tvl-depot/absl/hash/internal/hash.h

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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// -----------------------------------------------------------------------------
// File: hash.h
// -----------------------------------------------------------------------------
//
#ifndef ABSL_HASH_INTERNAL_HASH_H_
#define ABSL_HASH_INTERNAL_HASH_H_
#include <algorithm>
#include <array>
#include <cmath>
#include <cstring>
#include <deque>
#include <forward_list>
#include <functional>
#include <iterator>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <set>
#include <string>
#include <tuple>
#include <type_traits>
#include <utility>
#include <vector>
#include "absl/base/internal/endian.h"
#include "absl/base/port.h"
#include "absl/container/fixed_array.h"
#include "absl/meta/type_traits.h"
#include "absl/numeric/int128.h"
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "absl/types/variant.h"
#include "absl/utility/utility.h"
#include "absl/hash/internal/city.h"
namespace absl {
Export of internal Abseil changes -- c99f979ad34f155fbeeea69b88bdc7458d89a21c by Derek Mauro <dmauro@google.com>: Remove a floating point division by zero test. This isn't testing behavior related to the library, and MSVC warns about it in opt mode. PiperOrigin-RevId: 285220804 -- 68b015491f0dbf1ab547994673281abd1f34cd4b by Gennadiy Rozental <rogeeff@google.com>: This CL introduces following changes to the class FlagImpl: * We eliminate the CommandLineFlagLocks struct. Instead callback guard and callback function are combined into a single CallbackData struct, while primary data lock is stored separately. * CallbackData member of class FlagImpl is initially set to be nullptr and is only allocated and initialized when a flag's callback is being set. For most flags we do not pay for the extra space and extra absl::Mutex now. * Primary data guard is stored in data_guard_ data member. This is a properly aligned character buffer of necessary size. During initialization of the flag we construct absl::Mutex in this space using placement new call. * We now avoid extra value copy after successful attempt to parse value out of string. Instead we swap flag's current value with tentative value we just produced. PiperOrigin-RevId: 285132636 -- ed45d118fb818969eb13094cf7827c885dfc562c by Tom Manshreck <shreck@google.com>: Change null-term* (and nul-term*) to NUL-term* in comments PiperOrigin-RevId: 285036610 -- 729619017944db895ce8d6d29c1995aa2e5628a5 by Derek Mauro <dmauro@google.com>: Use the Posix implementation of thread identity on MinGW. Some versions of MinGW suffer from thread_local bugs. PiperOrigin-RevId: 285022920 -- 39a25493503c76885bc3254c28f66a251c5b5bb0 by Greg Falcon <gfalcon@google.com>: Implementation detail change. Add further ABSL_NAMESPACE_BEGIN and _END annotation macros to files in Abseil. PiperOrigin-RevId: 285012012 GitOrigin-RevId: c99f979ad34f155fbeeea69b88bdc7458d89a21c Change-Id: I4c85d3704e45d11a9ac50d562f39640a6adbedc1
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ABSL_NAMESPACE_BEGIN
namespace hash_internal {
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
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class PiecewiseCombiner;
// Internal detail: Large buffers are hashed in smaller chunks. This function
// returns the size of these chunks.
Export of internal Abseil changes -- 7f6c15aadc4d97e217dd446518dbb4fdc86b36a3 by Derek Mauro <dmauro@google.com>: Upgrade GCC automated testing to use GCC 9.2 and Cmake 3.16.2 PiperOrigin-RevId: 288488783 -- a978cee848d3cf65b0826c981bfd81022fc36660 by Abseil Team <absl-team@google.com>: Removing formatting traits that were only used internally. ON_CALL/EXPECT_CALL do a sufficient job here. PiperOrigin-RevId: 288386509 -- fdec6f40293d5883220f1f0ea1261f7c5b60a66e by Derek Mauro <dmauro@google.com>: Upgrade MacOS tests to use Bazel 2.0.0 PiperOrigin-RevId: 288373298 -- 465865c4123e9481ab50ea0527e92b39519704dd by Derek Mauro <dmauro@google.com>: Changes to support GCC 9 * Fix several -Wredundant-move warnings * Remove FlatHashMap.Any test, which basically doesn't work on any platform any more (see https://cplusplus.github.io/LWG/lwg-active.html#3121) * Fix a constant sign-compare warning * Conditionally compile out the PoisonHash test which doesn't build PiperOrigin-RevId: 288360204 -- 57c4bb07fc58e7dd2a04f3c45027aab5ecaccf25 by Andy Soffer <asoffer@google.com>: Deflaking MockingBitGen test. Because MockingBitGen can return random values, it is inherently flaky. For log-unifrom, 2040 is a common enough value that tests failed unreasonably frequently. Replacing it with a significantly larger value so as to be much less common. 50000 is a good choice because it is (tied for) the least likely to occur randomly from this distribution, but is still in the distribution. PiperOrigin-RevId: 288360112 -- 86f38e4109899d972de353b1c556c018cfe37956 by Matt Calabrese <calabrese@google.com>: Remove construction tests for the internal `CompressedTuple<std::any>` instantiation. This was not guaranteed to work for the reasons that `std::tuple<std::any>` copy construction does not actually work by standard specification (some implementations introduce workarounds for this). In GCC9, `CompressedTuple<std::any>` and `std::tuple<std::any>` both fail for the same reasons, and a proper "fix" requires updating `std::any`, which is out of our control. PiperOrigin-RevId: 288351977 GitOrigin-RevId: 7f6c15aadc4d97e217dd446518dbb4fdc86b36a3 Change-Id: I5d5c62bd297dc0ff1f2970ff076bb5cd088a7e4c
2020-01-07 15:56:49 +01:00
constexpr size_t PiecewiseChunkSize() { return 1024; }
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
// HashStateBase
//
// A hash state object represents an intermediate state in the computation
// of an unspecified hash algorithm. `HashStateBase` provides a CRTP style
// base class for hash state implementations. Developers adding type support
// for `absl::Hash` should not rely on any parts of the state object other than
// the following member functions:
//
// * HashStateBase::combine()
// * HashStateBase::combine_contiguous()
//
// A derived hash state class of type `H` must provide a static member function
// with a signature similar to the following:
//
// `static H combine_contiguous(H state, const unsigned char*, size_t)`.
//
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
// `HashStateBase` will provide a complete implementation for a hash state
// object in terms of this method.
//
// Example:
//
// // Use CRTP to define your derived class.
// struct MyHashState : HashStateBase<MyHashState> {
// static H combine_contiguous(H state, const unsigned char*, size_t);
// using MyHashState::HashStateBase::combine;
// using MyHashState::HashStateBase::combine_contiguous;
// };
template <typename H>
class HashStateBase {
public:
// HashStateBase::combine()
//
// Combines an arbitrary number of values into a hash state, returning the
// updated state.
//
// Each of the value types `T` must be separately hashable by the Abseil
// hashing framework.
//
// NOTE:
//
// state = H::combine(std::move(state), value1, value2, value3);
//
// is guaranteed to produce the same hash expansion as:
//
// state = H::combine(std::move(state), value1);
// state = H::combine(std::move(state), value2);
// state = H::combine(std::move(state), value3);
template <typename T, typename... Ts>
static H combine(H state, const T& value, const Ts&... values);
static H combine(H state) { return state; }
// HashStateBase::combine_contiguous()
//
// Combines a contiguous array of `size` elements into a hash state, returning
// the updated state.
//
// NOTE:
//
// state = H::combine_contiguous(std::move(state), data, size);
//
// is NOT guaranteed to produce the same hash expansion as a for-loop (it may
// perform internal optimizations). If you need this guarantee, use the
// for-loop instead.
template <typename T>
static H combine_contiguous(H state, const T* data, size_t size);
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
private:
friend class PiecewiseCombiner;
};
// is_uniquely_represented
//
// `is_uniquely_represented<T>` is a trait class that indicates whether `T`
// is uniquely represented.
//
// A type is "uniquely represented" if two equal values of that type are
// guaranteed to have the same bytes in their underlying storage. In other
// words, if `a == b`, then `memcmp(&a, &b, sizeof(T))` is guaranteed to be
// zero. This property cannot be detected automatically, so this trait is false
// by default, but can be specialized by types that wish to assert that they are
// uniquely represented. This makes them eligible for certain optimizations.
//
// If you have any doubt whatsoever, do not specialize this template.
// The default is completely safe, and merely disables some optimizations
// that will not matter for most types. Specializing this template,
// on the other hand, can be very hazardous.
//
// To be uniquely represented, a type must not have multiple ways of
// representing the same value; for example, float and double are not
// uniquely represented, because they have distinct representations for
// +0 and -0. Furthermore, the type's byte representation must consist
// solely of user-controlled data, with no padding bits and no compiler-
// controlled data such as vptrs or sanitizer metadata. This is usually
// very difficult to guarantee, because in most cases the compiler can
// insert data and padding bits at its own discretion.
//
// If you specialize this template for a type `T`, you must do so in the file
// that defines that type (or in this file). If you define that specialization
// anywhere else, `is_uniquely_represented<T>` could have different meanings
// in different places.
//
// The Enable parameter is meaningless; it is provided as a convenience,
// to support certain SFINAE techniques when defining specializations.
template <typename T, typename Enable = void>
struct is_uniquely_represented : std::false_type {};
// is_uniquely_represented<unsigned char>
//
// unsigned char is a synonym for "byte", so it is guaranteed to be
// uniquely represented.
template <>
struct is_uniquely_represented<unsigned char> : std::true_type {};
// is_uniquely_represented for non-standard integral types
//
// Integral types other than bool should be uniquely represented on any
// platform that this will plausibly be ported to.
template <typename Integral>
struct is_uniquely_represented<
Integral, typename std::enable_if<std::is_integral<Integral>::value>::type>
: std::true_type {};
// is_uniquely_represented<bool>
//
//
template <>
struct is_uniquely_represented<bool> : std::false_type {};
// hash_bytes()
//
// Convenience function that combines `hash_state` with the byte representation
// of `value`.
template <typename H, typename T>
H hash_bytes(H hash_state, const T& value) {
const unsigned char* start = reinterpret_cast<const unsigned char*>(&value);
return H::combine_contiguous(std::move(hash_state), start, sizeof(value));
}
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
// PiecewiseCombiner
//
// PiecewiseCombiner is an internal-only helper class for hashing a piecewise
// buffer of `char` or `unsigned char` as though it were contiguous. This class
// provides two methods:
//
// H add_buffer(state, data, size)
// H finalize(state)
//
// `add_buffer` can be called zero or more times, followed by a single call to
// `finalize`. This will produce the same hash expansion as concatenating each
// buffer piece into a single contiguous buffer, and passing this to
// `H::combine_contiguous`.
//
// Example usage:
// PiecewiseCombiner combiner;
// for (const auto& piece : pieces) {
// state = combiner.add_buffer(std::move(state), piece.data, piece.size);
// }
// return combiner.finalize(std::move(state));
class PiecewiseCombiner {
public:
PiecewiseCombiner() : position_(0) {}
PiecewiseCombiner(const PiecewiseCombiner&) = delete;
PiecewiseCombiner& operator=(const PiecewiseCombiner&) = delete;
// PiecewiseCombiner::add_buffer()
//
// Appends the given range of bytes to the sequence to be hashed, which may
// modify the provided hash state.
template <typename H>
H add_buffer(H state, const unsigned char* data, size_t size);
template <typename H>
H add_buffer(H state, const char* data, size_t size) {
return add_buffer(std::move(state),
reinterpret_cast<const unsigned char*>(data), size);
}
// PiecewiseCombiner::finalize()
//
// Finishes combining the hash sequence, which may may modify the provided
// hash state.
//
// Once finalize() is called, add_buffer() may no longer be called. The
// resulting hash state will be the same as if the pieces passed to
// add_buffer() were concatenated into a single flat buffer, and then provided
// to H::combine_contiguous().
template <typename H>
H finalize(H state);
private:
unsigned char buf_[PiecewiseChunkSize()];
size_t position_;
};
// -----------------------------------------------------------------------------
// AbslHashValue for Basic Types
// -----------------------------------------------------------------------------
// Note: Default `AbslHashValue` implementations live in `hash_internal`. This
// allows us to block lexical scope lookup when doing an unqualified call to
// `AbslHashValue` below. User-defined implementations of `AbslHashValue` can
// only be found via ADL.
// AbslHashValue() for hashing bool values
//
// We use SFINAE to ensure that this overload only accepts bool, not types that
// are convertible to bool.
template <typename H, typename B>
typename std::enable_if<std::is_same<B, bool>::value, H>::type AbslHashValue(
H hash_state, B value) {
return H::combine(std::move(hash_state),
static_cast<unsigned char>(value ? 1 : 0));
}
// AbslHashValue() for hashing enum values
template <typename H, typename Enum>
typename std::enable_if<std::is_enum<Enum>::value, H>::type AbslHashValue(
H hash_state, Enum e) {
// In practice, we could almost certainly just invoke hash_bytes directly,
// but it's possible that a sanitizer might one day want to
// store data in the unused bits of an enum. To avoid that risk, we
// convert to the underlying type before hashing. Hopefully this will get
// optimized away; if not, we can reopen discussion with c-toolchain-team.
return H::combine(std::move(hash_state),
static_cast<typename std::underlying_type<Enum>::type>(e));
}
// AbslHashValue() for hashing floating-point values
template <typename H, typename Float>
typename std::enable_if<std::is_same<Float, float>::value ||
std::is_same<Float, double>::value,
H>::type
AbslHashValue(H hash_state, Float value) {
return hash_internal::hash_bytes(std::move(hash_state),
value == 0 ? 0 : value);
}
// Long double has the property that it might have extra unused bytes in it.
// For example, in x86 sizeof(long double)==16 but it only really uses 80-bits
// of it. This means we can't use hash_bytes on a long double and have to
// convert it to something else first.
template <typename H, typename LongDouble>
typename std::enable_if<std::is_same<LongDouble, long double>::value, H>::type
AbslHashValue(H hash_state, LongDouble value) {
const int category = std::fpclassify(value);
switch (category) {
case FP_INFINITE:
// Add the sign bit to differentiate between +Inf and -Inf
hash_state = H::combine(std::move(hash_state), std::signbit(value));
break;
case FP_NAN:
case FP_ZERO:
default:
// Category is enough for these.
break;
case FP_NORMAL:
case FP_SUBNORMAL:
// We can't convert `value` directly to double because this would have
// undefined behavior if the value is out of range.
// std::frexp gives us a value in the range (-1, -.5] or [.5, 1) that is
// guaranteed to be in range for `double`. The truncation is
// implementation defined, but that works as long as it is deterministic.
int exp;
auto mantissa = static_cast<double>(std::frexp(value, &exp));
hash_state = H::combine(std::move(hash_state), mantissa, exp);
}
return H::combine(std::move(hash_state), category);
}
// AbslHashValue() for hashing pointers
template <typename H, typename T>
H AbslHashValue(H hash_state, T* ptr) {
Export of internal Abseil changes. -- 3d20ce6cd6541579abecaba169d4b8716d511272 by Jon Cohen <cohenjon@google.com>: Only use LSAN for clang version >= 3.5. This should fix https://github.com/abseil/abseil-cpp/issues/244 PiperOrigin-RevId: 234675129 -- e15bd4ec7a81aa95cc3d09fa1e0e81d58ae478fb by Conrad Parker <conradparker@google.com>: Fix errors in apply() sample code The following changes are made: * Make the example method public. * Give the two user functions different names to avoid confusion about whether apply() can select the correct overload of a function based on its tuple argument (it can't). * Pass tuple2 to the second example apply() invocation, instead of passing its contents individually. * Fix a s/tuple/tuple3/ typo in the third example apply() invocation. PiperOrigin-RevId: 234223407 -- de0ed71e21bc76ddf9fe715fdbaef74cd0df95c7 by Abseil Team <absl-team@google.com>: First test if a macro is defined to avoid -Wundef. ABSL clients may need to compile their code with the -Wundef warning flag. It will be helpful if ABSL header files can be compiled without the -Wundef warning. How to avoid the -Wundef warning: If a macro may be undefined, we need to first test whether the macro is defined before testing its value. We can't rely on the C preprocessor rule that an undefined macro has the value 0L. PiperOrigin-RevId: 234201123 -- fa484ad7dae0cac21140a96662809ecb0ec8eb5d by Abseil Team <absl-team@google.com>: Internal change. PiperOrigin-RevId: 234185697 -- d69b1baef681e27954b065375ecf9c2320463b2b by Samuel Benzaquen <sbenza@google.com>: Mix pointers more thoroughly. Some pointer alignments interact badly with the mixing constant. By mixing twice we reduce this problem. PiperOrigin-RevId: 234178401 -- 1041d0e474610f3a8fea0db90958857327d6da1c by Samuel Benzaquen <sbenza@google.com>: Record rehashes in the hashtablez struct. Only recording the probe length on insertion causes a huge overestimation of the total probe length at any given time. With natural growth, elements are inserted when the load factor is between (max load/2, max load). However, after a rehash the majority of elements are actually inserted when the load factor is less than max/2 and have a much lower average probe length. Also reset some values when the table is cleared. PiperOrigin-RevId: 234013580 -- 299205caf3c89c47339f7409bc831746602cea84 by Mark Barolak <mbar@google.com>: Fix a sample code snippet that assumes `absl::string_view::const_iterator` is `const char*`. This is generally true, however in C++17 builds, absl::string_view is an alias for std::string_view and on MSVC, the std::string_view::const_iterator is an object instead of just a pointer. PiperOrigin-RevId: 233844595 -- af6c6370cf51a1e6c1469c79dfb2a486a4009136 by Abseil Team <absl-team@google.com>: Internal change. PiperOrigin-RevId: 233773470 -- 6e59e4b8e2bb6101b448f0f32b0bea81fe399ccf by Abseil Team <absl-team@google.com>: fix typo in {Starts|Ends}WithIgnoreCase comment in match.h PiperOrigin-RevId: 233662951 GitOrigin-RevId: 3d20ce6cd6541579abecaba169d4b8716d511272 Change-Id: Ib9a29b1c38c6aedf5d9f3f7f00596e8d30e864dd
2019-02-19 23:29:09 +01:00
auto v = reinterpret_cast<uintptr_t>(ptr);
// Due to alignment, pointers tend to have low bits as zero, and the next few
// bits follow a pattern since they are also multiples of some base value.
// Mixing the pointer twice helps prevent stuck low bits for certain alignment
// values.
return H::combine(std::move(hash_state), v, v);
}
// AbslHashValue() for hashing nullptr_t
template <typename H>
H AbslHashValue(H hash_state, std::nullptr_t) {
return H::combine(std::move(hash_state), static_cast<void*>(nullptr));
}
// -----------------------------------------------------------------------------
// AbslHashValue for Composite Types
// -----------------------------------------------------------------------------
// is_hashable()
//
// Trait class which returns true if T is hashable by the absl::Hash framework.
// Used for the AbslHashValue implementations for composite types below.
template <typename T>
struct is_hashable;
// AbslHashValue() for hashing pairs
template <typename H, typename T1, typename T2>
typename std::enable_if<is_hashable<T1>::value && is_hashable<T2>::value,
H>::type
AbslHashValue(H hash_state, const std::pair<T1, T2>& p) {
return H::combine(std::move(hash_state), p.first, p.second);
}
// hash_tuple()
//
// Helper function for hashing a tuple. The third argument should
// be an index_sequence running from 0 to tuple_size<Tuple> - 1.
template <typename H, typename Tuple, size_t... Is>
H hash_tuple(H hash_state, const Tuple& t, absl::index_sequence<Is...>) {
return H::combine(std::move(hash_state), std::get<Is>(t)...);
}
// AbslHashValue for hashing tuples
template <typename H, typename... Ts>
Export of internal Abseil changes. -- 5f1ab09522226336830d9ea6ef7276d37f536ac5 by Abseil Team <absl-team@google.com>: Clarify the documentation of ABSL_MUST_USE_RESULT. PiperOrigin-RevId: 221663609 -- af4c8359a20d56369fd1dce318220cf3be03ca66 by Greg Falcon <gfalcon@google.com>: Internal change PiperOrigin-RevId: 221538448 -- 487cd09bd1942bf607080deeae38fee6ce66f294 by Eric Fiselier <ericwf@google.com>: Work around emscripten bugs and missing features in absl/time:time_test. The emscripten toolchain has a couple of issues that cause time_test to fail. Specifically: 1) emscripten doesn't support signals. 2) The javascript implementation of strftime/strptime use different expansions of '%c' that mean it doesn't round-trip. PiperOrigin-RevId: 221523701 -- 5823652e6a200b97b07334bc47128dfac40e20fc by Xiaoyi Zhang <zhangxy@google.com>: Fix MSVC compiler warning by explicitly casting to char. Currently our MSVC build breaks with the following error: raw_hash_set.h(406): warning C4309: 'argument': truncation of constant value PiperOrigin-RevId: 221492585 -- c5806358320711a5efbe5c523df13e14ab53a17d by Greg Falcon <gfalcon@google.com>: Replace calls to getpagesize() with the more portable sysconf(_SC_PAGESIZE); the latter is in POSIX 1.0 and is called out in the Linux `getpagesize` man page as a more portable spelling. PiperOrigin-RevId: 221492471 -- 19ffe82851072229bb7ce73f754ffe4c18e8c575 by Abseil Team <absl-team@google.com>: Fix -Wundef error in absl/hash/internal/hash.h. PiperOrigin-RevId: 221444120 -- b30f3d0a848563b6e4ec33f3dc085831dfabb748 by Jon Cohen <cohenjon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 221339736 GitOrigin-RevId: 5f1ab09522226336830d9ea6ef7276d37f536ac5 Change-Id: I96223d522d98bf6616dea88eb047c2d536eeddd0
2018-11-15 20:55:00 +01:00
#if defined(_MSC_VER)
// This SFINAE gets MSVC confused under some conditions. Let's just disable it
// for now.
H
Export of internal Abseil changes. -- 5f1ab09522226336830d9ea6ef7276d37f536ac5 by Abseil Team <absl-team@google.com>: Clarify the documentation of ABSL_MUST_USE_RESULT. PiperOrigin-RevId: 221663609 -- af4c8359a20d56369fd1dce318220cf3be03ca66 by Greg Falcon <gfalcon@google.com>: Internal change PiperOrigin-RevId: 221538448 -- 487cd09bd1942bf607080deeae38fee6ce66f294 by Eric Fiselier <ericwf@google.com>: Work around emscripten bugs and missing features in absl/time:time_test. The emscripten toolchain has a couple of issues that cause time_test to fail. Specifically: 1) emscripten doesn't support signals. 2) The javascript implementation of strftime/strptime use different expansions of '%c' that mean it doesn't round-trip. PiperOrigin-RevId: 221523701 -- 5823652e6a200b97b07334bc47128dfac40e20fc by Xiaoyi Zhang <zhangxy@google.com>: Fix MSVC compiler warning by explicitly casting to char. Currently our MSVC build breaks with the following error: raw_hash_set.h(406): warning C4309: 'argument': truncation of constant value PiperOrigin-RevId: 221492585 -- c5806358320711a5efbe5c523df13e14ab53a17d by Greg Falcon <gfalcon@google.com>: Replace calls to getpagesize() with the more portable sysconf(_SC_PAGESIZE); the latter is in POSIX 1.0 and is called out in the Linux `getpagesize` man page as a more portable spelling. PiperOrigin-RevId: 221492471 -- 19ffe82851072229bb7ce73f754ffe4c18e8c575 by Abseil Team <absl-team@google.com>: Fix -Wundef error in absl/hash/internal/hash.h. PiperOrigin-RevId: 221444120 -- b30f3d0a848563b6e4ec33f3dc085831dfabb748 by Jon Cohen <cohenjon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 221339736 GitOrigin-RevId: 5f1ab09522226336830d9ea6ef7276d37f536ac5 Change-Id: I96223d522d98bf6616dea88eb047c2d536eeddd0
2018-11-15 20:55:00 +01:00
#else // _MSC_VER
typename std::enable_if<absl::conjunction<is_hashable<Ts>...>::value, H>::type
Export of internal Abseil changes. -- 5f1ab09522226336830d9ea6ef7276d37f536ac5 by Abseil Team <absl-team@google.com>: Clarify the documentation of ABSL_MUST_USE_RESULT. PiperOrigin-RevId: 221663609 -- af4c8359a20d56369fd1dce318220cf3be03ca66 by Greg Falcon <gfalcon@google.com>: Internal change PiperOrigin-RevId: 221538448 -- 487cd09bd1942bf607080deeae38fee6ce66f294 by Eric Fiselier <ericwf@google.com>: Work around emscripten bugs and missing features in absl/time:time_test. The emscripten toolchain has a couple of issues that cause time_test to fail. Specifically: 1) emscripten doesn't support signals. 2) The javascript implementation of strftime/strptime use different expansions of '%c' that mean it doesn't round-trip. PiperOrigin-RevId: 221523701 -- 5823652e6a200b97b07334bc47128dfac40e20fc by Xiaoyi Zhang <zhangxy@google.com>: Fix MSVC compiler warning by explicitly casting to char. Currently our MSVC build breaks with the following error: raw_hash_set.h(406): warning C4309: 'argument': truncation of constant value PiperOrigin-RevId: 221492585 -- c5806358320711a5efbe5c523df13e14ab53a17d by Greg Falcon <gfalcon@google.com>: Replace calls to getpagesize() with the more portable sysconf(_SC_PAGESIZE); the latter is in POSIX 1.0 and is called out in the Linux `getpagesize` man page as a more portable spelling. PiperOrigin-RevId: 221492471 -- 19ffe82851072229bb7ce73f754ffe4c18e8c575 by Abseil Team <absl-team@google.com>: Fix -Wundef error in absl/hash/internal/hash.h. PiperOrigin-RevId: 221444120 -- b30f3d0a848563b6e4ec33f3dc085831dfabb748 by Jon Cohen <cohenjon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 221339736 GitOrigin-RevId: 5f1ab09522226336830d9ea6ef7276d37f536ac5 Change-Id: I96223d522d98bf6616dea88eb047c2d536eeddd0
2018-11-15 20:55:00 +01:00
#endif // _MSC_VER
AbslHashValue(H hash_state, const std::tuple<Ts...>& t) {
return hash_internal::hash_tuple(std::move(hash_state), t,
absl::make_index_sequence<sizeof...(Ts)>());
}
// -----------------------------------------------------------------------------
// AbslHashValue for Pointers
// -----------------------------------------------------------------------------
// AbslHashValue for hashing unique_ptr
template <typename H, typename T, typename D>
H AbslHashValue(H hash_state, const std::unique_ptr<T, D>& ptr) {
return H::combine(std::move(hash_state), ptr.get());
}
// AbslHashValue for hashing shared_ptr
template <typename H, typename T>
H AbslHashValue(H hash_state, const std::shared_ptr<T>& ptr) {
return H::combine(std::move(hash_state), ptr.get());
}
// -----------------------------------------------------------------------------
// AbslHashValue for String-Like Types
// -----------------------------------------------------------------------------
// AbslHashValue for hashing strings
//
// All the string-like types supported here provide the same hash expansion for
// the same character sequence. These types are:
//
// - `std::string` (and std::basic_string<char, std::char_traits<char>, A> for
// any allocator A)
// - `absl::string_view` and `std::string_view`
//
// For simplicity, we currently support only `char` strings. This support may
// be broadened, if necessary, but with some caution - this overload would
// misbehave in cases where the traits' `eq()` member isn't equivalent to `==`
// on the underlying character type.
template <typename H>
H AbslHashValue(H hash_state, absl::string_view str) {
return H::combine(
H::combine_contiguous(std::move(hash_state), str.data(), str.size()),
str.size());
}
Export of internal Abseil changes -- 049ac45508e335c6f010f2d28d71016b9fa65b4e by Derek Mauro <dmauro@google.com>: Fix librt detection PiperOrigin-RevId: 280207723 -- 6382c3a9fb2643af9dc031f92ca846c4a78e249c by Andy Getzendanner <durandal@google.com>: Fix Conan builds Import of https://github.com/abseil/abseil-cpp/pull/400 PiperOrigin-RevId: 280025424 -- aebcd52b1686ac82663a8d0193b60d0122a43372 by Samuel Benzaquen <sbenza@google.com>: Enable the assertion in the iterator's operator== and operator!= PiperOrigin-RevId: 279998951 -- 5b61d909e2159ac6fd45e0e456818db1e725ecd1 by Derek Mauro <dmauro@google.com>: Add best effort support for compiling much of Abseil with MinGW. This involves disabling ABSL_ATTRIBUTE_WEAK and adding link flags. A change to CCTZ is still necessary. Tests were not run yet, but most of them now build. PiperOrigin-RevId: 279966541 -- 4336f8b10cff906e2defdd7d1d449cde4907da5d by Abseil Team <absl-team@google.com>: Add comments and relax memory orders in base_internal::CallOnceImpl. Add a comment to document the memory order guarantee if base_internal::SpinLockWait() is called and returns kOnceDone. Add a comment for the load/store sequence in base_internal::CallOnceImpl based on Mike Burrows' explanation. The atomic load of 'control' in the #ifndef NDEBUG block does not need std::memory_order_acquire. It can use std::memory_order_relaxed. The atomic compare_exchange_strong of 'control' does not need std::memory_order_acquire in the success case. It can use std::memory_order_relaxed. PiperOrigin-RevId: 279814155 -- 407de3a5e9af957cded54a136ca0468bde620d4d by Abseil Team <absl-team@google.com>: Added a script to generate abseil.podspec from all BUILD.bazel files automatically. PiperOrigin-RevId: 279811441 -- 26139497d4a363d6c7bc989c554da593e8819a07 by Derek Mauro <dmauro@google.com>: Add missing copyright and Apache License to //absl/functional/BUILD.bazel PiperOrigin-RevId: 279795227 -- 98ed625b02af6e5834edf52a920d8ca2dab4cd90 by Matt Kulukundis <kfm@google.com>: Switch the implementation of hashtablez to *only* work on platforms that have a PER_THREAD_TLS. The old case is very slow (global mutex) and nobody collects data from that configuration anyway. PiperOrigin-RevId: 279775149 -- 07225900ef672c005c38f467ad3f92f38d0922b3 by Derek Mauro <dmauro@google.com>: Remove the minumum glibc version check PiperOrigin-RevId: 279750412 -- ec09956a951b4f52228ecc81968b8db7ae19ed15 by Derek Mauro <dmauro@google.com>: CMake only: link with -lrt to support older glibc versions PiperOrigin-RevId: 279741661 -- 97b113fb2e8246f6152c36330ba13793b37154b6 by Xiaoyi Zhang <zhangxy@google.com>: Internal change. PiperOrigin-RevId: 279390188 -- ca8f72f2721546cc9b01bd01b2ea144962e6e0c5 by Andy Getzendanner <durandal@google.com>: Expose PutTwoDigits for internal use within Abseil. PiperOrigin-RevId: 279374239 -- 14c6384cc03bbdfdefd2e4b635f104af5dd7e026 by Derek Mauro <dmauro@google.com>: Remove log_severity sources from the base target. They are already compiled as part of a separate library. PiperOrigin-RevId: 279372619 -- 3c5d926c718f8bf394e3bee87b6ba8d94601e0d3 by Abseil Team <absl-team@google.com>: s/indepdent/independent/g in SimpleAtof's documentation. PiperOrigin-RevId: 279350836 -- de2c44be8a8edf9efa1fe2007cba3564f3e5b0b8 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 279346990 -- 2ba078341423fcf6d0ba5ca1831f86570a26e615 by Samuel Benzaquen <sbenza@google.com>: Add hash support for std::wstring, std::u16string and std::u32string. PiperOrigin-RevId: 279320672 -- 3272d3ffcfa55283a04f90e5868701912da95ef7 by Andy Soffer <asoffer@google.com>: Removing a bunch of __restricts that amount to no performance differences. One of these is the cause of https://github.com/abseil/abseil-cpp/issues/396. In particular, in one of the Vector128Store functions, restricts on two pointers that were indeed aliased seems to be the root cause of the issues. Closes #396 PiperOrigin-RevId: 279318999 -- 342f338ab31cc24344d5de8f28cf455bbb629a17 by Jorg Brown <jorg@google.com>: Support uint128 in SimpleAtoi PiperOrigin-RevId: 279234038 -- 81cb0a04cf2dc4515d303679fc60968712191571 by Derek Mauro <dmauro@google.com>: Change the check for futex availability to support older Linux systems PiperOrigin-RevId: 279147079 -- cb4ca4aa4c8d2d710a5d483c56c4ce4f979e14b1 by Abseil Team <absl-team@google.com>: Add IWYU pragma: export for int128 .inc files. PiperOrigin-RevId: 279107098 -- b8df86ef610c366729f07326c726f3e34817b4dd by Abseil Team <absl-team@google.com>: An optimization for Waiter::Post() in the SEM waiter mode. Like the FUTEX waiter mode, Waiter::Post() only needs to call Poke() if it incremented the atomic variable from 0. PiperOrigin-RevId: 279086133 GitOrigin-RevId: 049ac45508e335c6f010f2d28d71016b9fa65b4e Change-Id: I4c1a4073fff62cb6a1fcb1c104aa7d62dad588c2
2019-11-13 17:54:32 +01:00
// Support std::wstring, std::u16string and std::u32string.
template <typename Char, typename Alloc, typename H,
typename = absl::enable_if_t<std::is_same<Char, wchar_t>::value ||
std::is_same<Char, char16_t>::value ||
std::is_same<Char, char32_t>::value>>
H AbslHashValue(
H hash_state,
const std::basic_string<Char, std::char_traits<Char>, Alloc>& str) {
return H::combine(
H::combine_contiguous(std::move(hash_state), str.data(), str.size()),
str.size());
}
// -----------------------------------------------------------------------------
// AbslHashValue for Sequence Containers
// -----------------------------------------------------------------------------
// AbslHashValue for hashing std::array
template <typename H, typename T, size_t N>
typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
H hash_state, const std::array<T, N>& array) {
return H::combine_contiguous(std::move(hash_state), array.data(),
array.size());
}
// AbslHashValue for hashing std::deque
template <typename H, typename T, typename Allocator>
typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
H hash_state, const std::deque<T, Allocator>& deque) {
// TODO(gromer): investigate a more efficient implementation taking
// advantage of the chunk structure.
for (const auto& t : deque) {
hash_state = H::combine(std::move(hash_state), t);
}
return H::combine(std::move(hash_state), deque.size());
}
// AbslHashValue for hashing std::forward_list
template <typename H, typename T, typename Allocator>
typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
H hash_state, const std::forward_list<T, Allocator>& list) {
size_t size = 0;
for (const T& t : list) {
hash_state = H::combine(std::move(hash_state), t);
++size;
}
return H::combine(std::move(hash_state), size);
}
// AbslHashValue for hashing std::list
template <typename H, typename T, typename Allocator>
typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
H hash_state, const std::list<T, Allocator>& list) {
for (const auto& t : list) {
hash_state = H::combine(std::move(hash_state), t);
}
return H::combine(std::move(hash_state), list.size());
}
// AbslHashValue for hashing std::vector
//
// Do not use this for vector<bool>. It does not have a .data(), and a fallback
// for std::hash<> is most likely faster.
template <typename H, typename T, typename Allocator>
typename std::enable_if<is_hashable<T>::value && !std::is_same<T, bool>::value,
H>::type
AbslHashValue(H hash_state, const std::vector<T, Allocator>& vector) {
return H::combine(H::combine_contiguous(std::move(hash_state), vector.data(),
vector.size()),
vector.size());
}
// -----------------------------------------------------------------------------
// AbslHashValue for Ordered Associative Containers
// -----------------------------------------------------------------------------
// AbslHashValue for hashing std::map
template <typename H, typename Key, typename T, typename Compare,
typename Allocator>
typename std::enable_if<is_hashable<Key>::value && is_hashable<T>::value,
H>::type
AbslHashValue(H hash_state, const std::map<Key, T, Compare, Allocator>& map) {
for (const auto& t : map) {
hash_state = H::combine(std::move(hash_state), t);
}
return H::combine(std::move(hash_state), map.size());
}
// AbslHashValue for hashing std::multimap
template <typename H, typename Key, typename T, typename Compare,
typename Allocator>
typename std::enable_if<is_hashable<Key>::value && is_hashable<T>::value,
H>::type
AbslHashValue(H hash_state,
const std::multimap<Key, T, Compare, Allocator>& map) {
for (const auto& t : map) {
hash_state = H::combine(std::move(hash_state), t);
}
return H::combine(std::move(hash_state), map.size());
}
// AbslHashValue for hashing std::set
template <typename H, typename Key, typename Compare, typename Allocator>
typename std::enable_if<is_hashable<Key>::value, H>::type AbslHashValue(
H hash_state, const std::set<Key, Compare, Allocator>& set) {
for (const auto& t : set) {
hash_state = H::combine(std::move(hash_state), t);
}
return H::combine(std::move(hash_state), set.size());
}
// AbslHashValue for hashing std::multiset
template <typename H, typename Key, typename Compare, typename Allocator>
typename std::enable_if<is_hashable<Key>::value, H>::type AbslHashValue(
H hash_state, const std::multiset<Key, Compare, Allocator>& set) {
for (const auto& t : set) {
hash_state = H::combine(std::move(hash_state), t);
}
return H::combine(std::move(hash_state), set.size());
}
// -----------------------------------------------------------------------------
// AbslHashValue for Wrapper Types
// -----------------------------------------------------------------------------
// AbslHashValue for hashing absl::optional
template <typename H, typename T>
typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
H hash_state, const absl::optional<T>& opt) {
if (opt) hash_state = H::combine(std::move(hash_state), *opt);
return H::combine(std::move(hash_state), opt.has_value());
}
// VariantVisitor
template <typename H>
struct VariantVisitor {
H&& hash_state;
template <typename T>
H operator()(const T& t) const {
return H::combine(std::move(hash_state), t);
}
};
// AbslHashValue for hashing absl::variant
template <typename H, typename... T>
typename std::enable_if<conjunction<is_hashable<T>...>::value, H>::type
AbslHashValue(H hash_state, const absl::variant<T...>& v) {
if (!v.valueless_by_exception()) {
hash_state = absl::visit(VariantVisitor<H>{std::move(hash_state)}, v);
}
return H::combine(std::move(hash_state), v.index());
}
// -----------------------------------------------------------------------------
// AbslHashValue for Other Types
// -----------------------------------------------------------------------------
// AbslHashValue for hashing std::bitset is not defined, for the same reason as
// for vector<bool> (see std::vector above): It does not expose the raw bytes,
// and a fallback to std::hash<> is most likely faster.
// -----------------------------------------------------------------------------
// hash_range_or_bytes()
//
// Mixes all values in the range [data, data+size) into the hash state.
// This overload accepts only uniquely-represented types, and hashes them by
// hashing the entire range of bytes.
template <typename H, typename T>
typename std::enable_if<is_uniquely_represented<T>::value, H>::type
hash_range_or_bytes(H hash_state, const T* data, size_t size) {
const auto* bytes = reinterpret_cast<const unsigned char*>(data);
return H::combine_contiguous(std::move(hash_state), bytes, sizeof(T) * size);
}
// hash_range_or_bytes()
template <typename H, typename T>
typename std::enable_if<!is_uniquely_represented<T>::value, H>::type
hash_range_or_bytes(H hash_state, const T* data, size_t size) {
for (const auto end = data + size; data < end; ++data) {
hash_state = H::combine(std::move(hash_state), *data);
}
return hash_state;
}
#if defined(ABSL_INTERNAL_LEGACY_HASH_NAMESPACE) && \
Export of internal Abseil changes. -- 6fdf24a197b964f9bacbebd0ceca305aef1654fc by Shaindel Schwartz <shaindel@google.com>: Internal change PiperOrigin-RevId: 231627312 -- 65f7faf52bff01384171efb85fee159378dedf70 by CJ Johnson <johnsoncj@google.com>: Relocates the definitions of the InputIterator-accepting parts of the InlinedVector API into the top-level. The removed functions had no other callers so there was no reason to keep the layer of indirection in the form of the function call. PiperOrigin-RevId: 231527459 -- 30e105b749b5ecc50fdaf26c7da589617efce425 by CJ Johnson <johnsoncj@google.com>: Relocates closing brace for absl namespace in InlinedVector to the correct end location PiperOrigin-RevId: 231477871 -- 063c1e8b9d1f032662c46d574e20ecc357b87d0c by Eric Fiselier <ericwf@google.com>: Cleanup std::hash probing metafunctions. Previously there were two different ways to probe for std::hash. One in hash.h and another in type_traits.h, and they were both implemented differently, and neither correctly worked around bad STL implementations. This patch unifies the implementations into a single IsHashable trait. It also: * Correctly checks for old libc++ versions where this won't work. * Avoids undefined behavior which resulted from calling std::is_constructible incomplete types. * Unifies the feature test macro used in the headers and the tests. Additionally it also slightly changes the behavior of when absl::variant is hashable. Previously we disable hashing when std::hash<T>()(key) was formed but when std::hash<T> couldn't be destructed. This seems wrong. If a user provides a evil specialization of std::hash, then it's OK for variant's hash to blow up. PiperOrigin-RevId: 231468345 -- 05d75dd4b07c893de9b104731644d0d207b01253 by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 231397518 -- a0ee9032f9e04039f3410ed17fcf45ae1a3868f5 by CJ Johnson <johnsoncj@google.com>: Remove unused EnableIfAtLeastInputIterator from InlinedVector PiperOrigin-RevId: 231348903 -- 4dcd4e9a6780a81d7a6974c7bf22a037e6482b49 by Abseil Team <absl-team@google.com>: Remove unnecessary register keyword from absl/base/internal/endian.h. PiperOrigin-RevId: 231316570 -- c8584836caa3a10f90a8604a85d4b831310b72ee by Abseil Team <absl-team@google.com>: Fix hashtablez_sampler compilation on older Android NDK builds PiperOrigin-RevId: 231283542 GitOrigin-RevId: 6fdf24a197b964f9bacbebd0ceca305aef1654fc Change-Id: I185b12fb8347e3ad0ffcb2cbb83a53450e5eb938
2019-01-30 19:59:43 +01:00
ABSL_META_INTERNAL_STD_HASH_SFINAE_FRIENDLY_
#define ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_ 1
Export of internal Abseil changes. -- 5f1ab09522226336830d9ea6ef7276d37f536ac5 by Abseil Team <absl-team@google.com>: Clarify the documentation of ABSL_MUST_USE_RESULT. PiperOrigin-RevId: 221663609 -- af4c8359a20d56369fd1dce318220cf3be03ca66 by Greg Falcon <gfalcon@google.com>: Internal change PiperOrigin-RevId: 221538448 -- 487cd09bd1942bf607080deeae38fee6ce66f294 by Eric Fiselier <ericwf@google.com>: Work around emscripten bugs and missing features in absl/time:time_test. The emscripten toolchain has a couple of issues that cause time_test to fail. Specifically: 1) emscripten doesn't support signals. 2) The javascript implementation of strftime/strptime use different expansions of '%c' that mean it doesn't round-trip. PiperOrigin-RevId: 221523701 -- 5823652e6a200b97b07334bc47128dfac40e20fc by Xiaoyi Zhang <zhangxy@google.com>: Fix MSVC compiler warning by explicitly casting to char. Currently our MSVC build breaks with the following error: raw_hash_set.h(406): warning C4309: 'argument': truncation of constant value PiperOrigin-RevId: 221492585 -- c5806358320711a5efbe5c523df13e14ab53a17d by Greg Falcon <gfalcon@google.com>: Replace calls to getpagesize() with the more portable sysconf(_SC_PAGESIZE); the latter is in POSIX 1.0 and is called out in the Linux `getpagesize` man page as a more portable spelling. PiperOrigin-RevId: 221492471 -- 19ffe82851072229bb7ce73f754ffe4c18e8c575 by Abseil Team <absl-team@google.com>: Fix -Wundef error in absl/hash/internal/hash.h. PiperOrigin-RevId: 221444120 -- b30f3d0a848563b6e4ec33f3dc085831dfabb748 by Jon Cohen <cohenjon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 221339736 GitOrigin-RevId: 5f1ab09522226336830d9ea6ef7276d37f536ac5 Change-Id: I96223d522d98bf6616dea88eb047c2d536eeddd0
2018-11-15 20:55:00 +01:00
#else
#define ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_ 0
#endif
// HashSelect
//
// Type trait to select the appropriate hash implementation to use.
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
// HashSelect::type<T> will give the proper hash implementation, to be invoked
// as:
// HashSelect::type<T>::Invoke(state, value)
// Also, HashSelect::type<T>::value is a boolean equal to `true` if there is a
// valid `Invoke` function. Types that are not hashable will have a ::value of
// `false`.
struct HashSelect {
private:
struct State : HashStateBase<State> {
static State combine_contiguous(State hash_state, const unsigned char*,
size_t);
using State::HashStateBase::combine_contiguous;
};
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
struct UniquelyRepresentedProbe {
template <typename H, typename T>
static auto Invoke(H state, const T& value)
-> absl::enable_if_t<is_uniquely_represented<T>::value, H> {
return hash_internal::hash_bytes(std::move(state), value);
}
};
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
struct HashValueProbe {
template <typename H, typename T>
static auto Invoke(H state, const T& value) -> absl::enable_if_t<
std::is_same<H,
decltype(AbslHashValue(std::move(state), value))>::value,
H> {
return AbslHashValue(std::move(state), value);
}
};
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
struct LegacyHashProbe {
#if ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
template <typename H, typename T>
static auto Invoke(H state, const T& value) -> absl::enable_if_t<
std::is_convertible<
decltype(ABSL_INTERNAL_LEGACY_HASH_NAMESPACE::hash<T>()(value)),
size_t>::value,
H> {
return hash_internal::hash_bytes(
std::move(state),
ABSL_INTERNAL_LEGACY_HASH_NAMESPACE::hash<T>{}(value));
}
#endif // ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
};
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
struct StdHashProbe {
template <typename H, typename T>
static auto Invoke(H state, const T& value)
-> absl::enable_if_t<type_traits_internal::IsHashable<T>::value, H> {
return hash_internal::hash_bytes(std::move(state), std::hash<T>{}(value));
}
};
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
template <typename Hash, typename T>
struct Probe : Hash {
private:
template <typename H, typename = decltype(H::Invoke(
std::declval<State>(), std::declval<const T&>()))>
static std::true_type Test(int);
template <typename U>
static std::false_type Test(char);
public:
static constexpr bool value = decltype(Test<Hash>(0))::value;
};
public:
// Probe each implementation in order.
Export of internal Abseil changes. -- 5a5dba4252e764e6737070bf0a31074bf23a3b41 by Abseil Team <absl-team@google.com>: Internal change. PiperOrigin-RevId: 244898913 -- 3eb7d5b445ffbf08a104e39cd15aecf568417333 by Matt Calabrese <calabrese@google.com>: Introduce absl::is_trivially_move_constructible and absl::is_trivially_move_assignable, and update the absl::is_trivially_copy_constructible and absl::is_trivially_copy_assignable traits to use similar techniques (should now be closer to the standard behavior). PiperOrigin-RevId: 244859015 -- 7da05a24fa786cab3985de0c39a186d73dcbcfb5 by Abseil Team <absl-team@google.com>: Fix misspellings in comments in raw_hash_set.h. PiperOrigin-RevId: 244754700 -- 5c057be96048f21473d5ec45005ab4dcd8dd354f by Derek Mauro <dmauro@google.com>: Internal change PiperOrigin-RevId: 244744239 -- 592394e3c2e98f1238d3fb6fcb0d20c3e3739ba9 by Derek Mauro <dmauro@google.com>: Limit the raw_hash_set prefetch test to x86-64. PiperOrigin-RevId: 244737534 -- 99ebe4e003633c8ff7838b035b31a827994879ef by Derek Mauro <dmauro@google.com>: Workaround warning 4091 in an MSVC header. PiperOrigin-RevId: 244701744 -- 0aa23f09a32efe7985ee55b0217190f08da42477 by Abseil Team <absl-team@google.com>: Fix comment typo. PiperOrigin-RevId: 244659371 -- c6cdb87e9f28062c8daa29b3d8d68182ecc16383 by Derek Mauro <dmauro@google.com>: Fix -Wundef warnings and support -Wundef. PiperOrigin-RevId: 244244968 -- 06b81245f7696b20c3c63b0618d33ac25e29cad6 by Abseil Team <absl-team@google.com>: Fix a typo in inlined_vector.h. PiperOrigin-RevId: 244230809 -- 94877a2125d2cfe837384240e4d6551f39d737e4 by Greg Falcon <gfalcon@google.com>: Fix sysinfo_test for emscripten. PiperOrigin-RevId: 244198804 -- ec7783531ef7f9df2da37d341d61f7cb2bf843f0 by Shaindel Schwartz <shaindel@google.com>: Import of CCTZ from GitHub. Fixes #291. PiperOrigin-RevId: 244184598 -- b652c14fa95ea206c217487ee713b11f5d1762b3 by Matt Calabrese <calabrese@google.com>: Emulate the `in_place_index` and `in_place_type` variable templates such that they are syntactically usable in C++11 with `any` and `variant`. Also pull in the variable templates from namespace std when available. The main observable differences here are: 1) The types of `in_place_index_t<I>` and `in_place_type_t<T>` become function pointer types rather than structs when using the implementation that is not an alias of the std equivalents. 2) The types of `in_place_index<I>` and `in_place_type<T>` are not directly `in_place_index_t<I>` and `in_place_type_t<T>`, but rather they become function types that decay to the corresponding function pointer types. 3) The default constructor for `in_place_index_t` and `in_place_type_t` instantiations is no longer explicit, but for these templates I think that's less important than for something like `in_place_t` since the _type_t and _index_t versions basically never have their template parameter non-deduced when participating in overload resolution with conflicting candidates. 4) While idiomatic usage of `in_place_type_t` and `in_place_index_t` with std::variant and std::any should not be affected, there is the possibility that strange, non-idiomatic uses may be affected in the wild. 5) Default construction (rather than value-initialization) leads to a default-constructed pointer. PiperOrigin-RevId: 244180003 -- b9ac5a96581837ffa24532117b7ea302a5569751 by Derek Mauro <dmauro@google.com>: Fix MSVC debug assertion. isprint is undefined for values not representable as unsigned char or EOF. PiperOrigin-RevId: 244083005 -- 41758be6137c2f25e84b50f23938e49484be2903 by Shaindel Schwartz <shaindel@google.com>: Update config settings for Apple platforms. PiperOrigin-RevId: 244040587 -- c90df6a26db94b0305a0c954455a621542a89d91 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 244024427 -- c71e9ceb89495354eca7d02bd905ffeaa9029aec by Derek Mauro <dmauro@google.com>: Adds missing ABSL_DEFAULT_COPTS and ABSL_TEST_COPTS to CMakeLists.txt Don't error on deprecated declarations in tests. It is completely reasonable to test that code marked deprecated still works. PiperOrigin-RevId: 244003941 -- e1326a96527a8ba9b8d120161545260da9c4562e by Abseil Team <absl-team@google.com>: Internal change. PiperOrigin-RevId: 243990623 -- 90b8e12934c7711e1bfcc0117d21288bf9220dee by Abseil Team <absl-team@google.com>: Add variation of absl::Base64Escape/WebSafeBase64Escape that directly returns its result. PiperOrigin-RevId: 243894308 -- 317fef3344481ebc5c35712d42f5d8a0fa64dff4 by Abseil Team <absl-team@google.com>: Enable raw logging in Emscripten builds. PiperOrigin-RevId: 243893705 GitOrigin-RevId: 5a5dba4252e764e6737070bf0a31074bf23a3b41 Change-Id: I19293aab73cc98d9e9bf6a9fdc30819764adb9db
2019-04-23 21:04:13 +02:00
// disjunction provides short circuiting wrt instantiation.
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
template <typename T>
using Apply = absl::disjunction< //
Probe<UniquelyRepresentedProbe, T>, //
Probe<HashValueProbe, T>, //
Probe<LegacyHashProbe, T>, //
Probe<StdHashProbe, T>, //
std::false_type>;
};
template <typename T>
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
struct is_hashable
: std::integral_constant<bool, HashSelect::template Apply<T>::value> {};
// CityHashState
Export of internal Abseil changes -- 8bdb2020150ed0fd4a4e520e454dc5f54e33f776 by Eric Fiselier <ericwf@google.com>: Workaround bug in GCC 9.2 and after. PiperOrigin-RevId: 291982551 -- 47ff4820e595f96c082a90d733725f6882d83e3b by Abseil Team <absl-team@google.com>: Improve ABSL_ATTRIBUTE_PACKED documentation Recommend to apply ABSL_ATTRIBUTE_PACKED to structure members instead of to an entire structure because applying this attribute to an entire structure may cause the compiler to generate suboptimal code. It reduces the alignment of the data structure from a value larger than one to one. When applied to a structure, ABSL_ATTRIBUTE_PACKED reduces the alignment of a structure (alignof()) to 1. As a result, the compiler can no longer assume that e.g. uint32 members are aligned on a four byte boundary and hence is forced to use single-byte load and store instructions on CPU architectures that do not support non-aligned loads or stores. PiperOrigin-RevId: 291977920 -- 902b7a86f860da699d3a2e5c738be5ef73ede3b4 by Mark Barolak <mbar@google.com>: Internal change PiperOrigin-RevId: 291963048 -- bb3bd3247e376d53a3080b105f13ec7566d3ae50 by Abseil Team <absl-team@google.com>: Support the C++17 insert_or_assign() API in btree_map. PiperOrigin-RevId: 291945474 -- ff3b3cfcbbc64f086f95501f48d49426bcde356f by Gennadiy Rozental <rogeeff@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 291861110 -- fd465cd9cbbacd3962f67a7346d6462edaddd809 by Derek Mauro <dmauro@google.com>: Add flaky=1 to beta_distribution_test. PiperOrigin-RevId: 291757364 -- 3603adfb59c4128c542b670952cce250d59e1f67 by Derek Mauro <dmauro@google.com>: Separate the initialization of NumCPUs() and NominalCPUFrequency() The OSS version of Abseil never needs to call NominalCPUFrequency(). In some configurations, initializing NominalCPUFrequency() requires spending at least 3ms measuring the CPU frequency. By separating the initialization from NumCPUs(), which is called in most configurations, we can save at least 3ms of program startup time. PiperOrigin-RevId: 291737273 -- bea9e4a6bff5a0351d340deab966641867e08c4d by Abseil Team <absl-team@google.com>: Change the cmake library names not to have a redundant `absl_` prefix. PiperOrigin-RevId: 291640501 -- 501b602ef260cd7c8c527342581ceffb3c5b6d4c by Gennadiy Rozental <rogeeff@google.com>: Introducing benchmark for absl::GetFlag. PiperOrigin-RevId: 291433394 -- 4eeaddc788da4b91c272a8adca77ca6dbbbc1d44 by Xiaoyi Zhang <zhangxy@google.com>: fix: Add support for more ARM processors detection Import of https://github.com/abseil/abseil-cpp/pull/608 PiperOrigin-RevId: 291420397 -- a3087a8e883c5d71de7d9bd4ec8f4db5142dfcf5 by Derek Mauro <dmauro@google.com>: Removes the flaky raw_hash_set prefetch test PiperOrigin-RevId: 291197079 -- aad6c2121c102ac36216e771c83227cf3e3bfd66 by Andy Soffer <asoffer@google.com>: Enable building Abseil as a DLL. This is currently experimental and unsupported. This CL does a few things: 1. Adds the ABSL_DLL macro to any class holding a static data member, or to global constants in headers. 2. Adds a whitelist of all files in the DLL and all the build targets that are conglomerated into the DLL. 3. When BUILD_SHARED_LIBS is specified, any build target that would be in the DLL still exists, but we swap out all of it's dependencies so it just depends on abseil_dll PiperOrigin-RevId: 291192055 -- 5e888cd6f2a7722805d41f872108a03a84e421c7 by Mark Barolak <mbar@google.com>: Move absl/strings/internal/escaping.{cc,h} into internal build targets. This puts absl/strings/internal/escaping.h behind a whitelist and it also resolves https://github.com/abseil/abseil-cpp/issues/604. PiperOrigin-RevId: 291173320 -- 166836d24970da87587c1728036f53f05a28f0af by Eric Fiselier <ericwf@google.com>: Internal Change. PiperOrigin-RevId: 291012718 -- 996ddb3dffda02440fa93f30ca5d71b14b688875 by Abseil Team <absl-team@google.com>: Fix shared libraries log spam for built-in types in absl::GetFlag PiperOrigin-RevId: 290772743 GitOrigin-RevId: 8bdb2020150ed0fd4a4e520e454dc5f54e33f776 Change-Id: I8bf2265dd14ebbace220a1b6b982bb5040ad2a26
2020-01-28 20:50:11 +01:00
class ABSL_DLL CityHashState
: public HashStateBase<CityHashState> {
// absl::uint128 is not an alias or a thin wrapper around the intrinsic.
// We use the intrinsic when available to improve performance.
#ifdef ABSL_HAVE_INTRINSIC_INT128
using uint128 = __uint128_t;
#else // ABSL_HAVE_INTRINSIC_INT128
using uint128 = absl::uint128;
#endif // ABSL_HAVE_INTRINSIC_INT128
static constexpr uint64_t kMul =
sizeof(size_t) == 4 ? uint64_t{0xcc9e2d51}
: uint64_t{0x9ddfea08eb382d69};
template <typename T>
using IntegralFastPath =
conjunction<std::is_integral<T>, is_uniquely_represented<T>>;
public:
// Move only
CityHashState(CityHashState&&) = default;
CityHashState& operator=(CityHashState&&) = default;
// CityHashState::combine_contiguous()
//
// Fundamental base case for hash recursion: mixes the given range of bytes
// into the hash state.
static CityHashState combine_contiguous(CityHashState hash_state,
const unsigned char* first,
size_t size) {
return CityHashState(
CombineContiguousImpl(hash_state.state_, first, size,
std::integral_constant<int, sizeof(size_t)>{}));
}
using CityHashState::HashStateBase::combine_contiguous;
// CityHashState::hash()
//
// For performance reasons in non-opt mode, we specialize this for
// integral types.
// Otherwise we would be instantiating and calling dozens of functions for
// something that is just one multiplication and a couple xor's.
// The result should be the same as running the whole algorithm, but faster.
template <typename T, absl::enable_if_t<IntegralFastPath<T>::value, int> = 0>
static size_t hash(T value) {
return static_cast<size_t>(Mix(Seed(), static_cast<uint64_t>(value)));
}
// Overload of CityHashState::hash()
template <typename T, absl::enable_if_t<!IntegralFastPath<T>::value, int> = 0>
static size_t hash(const T& value) {
return static_cast<size_t>(combine(CityHashState{}, value).state_);
}
private:
// Invoked only once for a given argument; that plus the fact that this is
// move-only ensures that there is only one non-moved-from object.
CityHashState() : state_(Seed()) {}
// Workaround for MSVC bug.
// We make the type copyable to fix the calling convention, even though we
// never actually copy it. Keep it private to not affect the public API of the
// type.
CityHashState(const CityHashState&) = default;
explicit CityHashState(uint64_t state) : state_(state) {}
// Implementation of the base case for combine_contiguous where we actually
// mix the bytes into the state.
// Dispatch to different implementations of the combine_contiguous depending
// on the value of `sizeof(size_t)`.
static uint64_t CombineContiguousImpl(uint64_t state,
const unsigned char* first, size_t len,
std::integral_constant<int, 4>
/* sizeof_size_t */);
static uint64_t CombineContiguousImpl(uint64_t state,
const unsigned char* first, size_t len,
std::integral_constant<int, 8>
/* sizeof_size_t*/);
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
// Slow dispatch path for calls to CombineContiguousImpl with a size argument
// larger than PiecewiseChunkSize(). Has the same effect as calling
// CombineContiguousImpl() repeatedly with the chunk stride size.
static uint64_t CombineLargeContiguousImpl32(uint64_t state,
const unsigned char* first,
size_t len);
static uint64_t CombineLargeContiguousImpl64(uint64_t state,
const unsigned char* first,
size_t len);
// Reads 9 to 16 bytes from p.
// The first 8 bytes are in .first, the rest (zero padded) bytes are in
// .second.
static std::pair<uint64_t, uint64_t> Read9To16(const unsigned char* p,
size_t len) {
uint64_t high = little_endian::Load64(p + len - 8);
return {little_endian::Load64(p), high >> (128 - len * 8)};
}
// Reads 4 to 8 bytes from p. Zero pads to fill uint64_t.
static uint64_t Read4To8(const unsigned char* p, size_t len) {
return (static_cast<uint64_t>(little_endian::Load32(p + len - 4))
<< (len - 4) * 8) |
little_endian::Load32(p);
}
// Reads 1 to 3 bytes from p. Zero pads to fill uint32_t.
static uint32_t Read1To3(const unsigned char* p, size_t len) {
return static_cast<uint32_t>((p[0]) | //
(p[len / 2] << (len / 2 * 8)) | //
(p[len - 1] << ((len - 1) * 8)));
}
ABSL_ATTRIBUTE_ALWAYS_INLINE static uint64_t Mix(uint64_t state, uint64_t v) {
using MultType =
absl::conditional_t<sizeof(size_t) == 4, uint64_t, uint128>;
// We do the addition in 64-bit space to make sure the 128-bit
// multiplication is fast. If we were to do it as MultType the compiler has
// to assume that the high word is non-zero and needs to perform 2
// multiplications instead of one.
MultType m = state + v;
m *= kMul;
return static_cast<uint64_t>(m ^ (m >> (sizeof(m) * 8 / 2)));
}
// Seed()
//
// A non-deterministic seed.
//
// The current purpose of this seed is to generate non-deterministic results
// and prevent having users depend on the particular hash values.
// It is not meant as a security feature right now, but it leaves the door
// open to upgrade it to a true per-process random seed. A true random seed
// costs more and we don't need to pay for that right now.
//
// On platforms with ASLR, we take advantage of it to make a per-process
// random value.
// See https://en.wikipedia.org/wiki/Address_space_layout_randomization
//
// On other platforms this is still going to be non-deterministic but most
// probably per-build and not per-process.
ABSL_ATTRIBUTE_ALWAYS_INLINE static uint64_t Seed() {
return static_cast<uint64_t>(reinterpret_cast<uintptr_t>(kSeed));
}
static const void* const kSeed;
uint64_t state_;
};
// CityHashState::CombineContiguousImpl()
inline uint64_t CityHashState::CombineContiguousImpl(
uint64_t state, const unsigned char* first, size_t len,
std::integral_constant<int, 4> /* sizeof_size_t */) {
// For large values we use CityHash, for small ones we just use a
// multiplicative hash.
uint64_t v;
if (len > 8) {
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
if (ABSL_PREDICT_FALSE(len > PiecewiseChunkSize())) {
return CombineLargeContiguousImpl32(state, first, len);
}
v = absl::hash_internal::CityHash32(reinterpret_cast<const char*>(first), len);
} else if (len >= 4) {
v = Read4To8(first, len);
} else if (len > 0) {
v = Read1To3(first, len);
} else {
// Empty ranges have no effect.
return state;
}
return Mix(state, v);
}
// Overload of CityHashState::CombineContiguousImpl()
inline uint64_t CityHashState::CombineContiguousImpl(
uint64_t state, const unsigned char* first, size_t len,
std::integral_constant<int, 8> /* sizeof_size_t */) {
// For large values we use CityHash, for small ones we just use a
// multiplicative hash.
uint64_t v;
if (len > 16) {
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
if (ABSL_PREDICT_FALSE(len > PiecewiseChunkSize())) {
return CombineLargeContiguousImpl64(state, first, len);
}
v = absl::hash_internal::CityHash64(reinterpret_cast<const char*>(first), len);
} else if (len > 8) {
auto p = Read9To16(first, len);
state = Mix(state, p.first);
v = p.second;
} else if (len >= 4) {
v = Read4To8(first, len);
} else if (len > 0) {
v = Read1To3(first, len);
} else {
// Empty ranges have no effect.
return state;
}
return Mix(state, v);
}
struct AggregateBarrier {};
// HashImpl
// Add a private base class to make sure this type is not an aggregate.
// Aggregates can be aggregate initialized even if the default constructor is
// deleted.
struct PoisonedHash : private AggregateBarrier {
PoisonedHash() = delete;
PoisonedHash(const PoisonedHash&) = delete;
PoisonedHash& operator=(const PoisonedHash&) = delete;
};
template <typename T>
struct HashImpl {
size_t operator()(const T& value) const { return CityHashState::hash(value); }
};
template <typename T>
struct Hash
: absl::conditional_t<is_hashable<T>::value, HashImpl<T>, PoisonedHash> {};
template <typename H>
template <typename T, typename... Ts>
H HashStateBase<H>::combine(H state, const T& value, const Ts&... values) {
Export of internal Abseil changes. -- 5dc8d7504b7c11710b19365a6582c288c8992366 by Derek Mauro <dmauro@google.com>: Fix constexpr Span::last under MSVC and add Span constexpr tests. PiperOrigin-RevId: 237515952 -- 5ea8c146e653bbc49ff7e698699478242df7de35 by Derek Mauro <dmauro@google.com>: Implement Span::first and Span::last from C++20. https://github.com/abseil/abseil-cpp/pull/274 PiperOrigin-RevId: 237494399 -- 08db3417f1d8fe4556255d57a2f0df51b09bdd9a by Derek Mauro <dmauro@google.com>: HTTPS in more URLs. PiperOrigin-RevId: 237486823 -- 83ec63a7f8e47b62af619546f9f7b3bf72e74e86 by Derek Mauro <dmauro@google.com>: Changed HTTP URLs to HTTPS where possible. https://github.com/abseil/abseil-cpp/pull/270 PiperOrigin-RevId: 237445310 -- 220bf279c14cb31efa239500d1a70e0ac0c32e3c by Abseil Team <absl-team@google.com>: Support parsing decltype(nullptr) as a type. PiperOrigin-RevId: 237336739 -- ced234bbe78f5d495c3f6f6a9c2e0a95f7c080a5 by Gennadiy Rozental <rogeeff@google.com>: Introduce internal interface for setting environment variable value in scope PiperOrigin-RevId: 237275806 -- 1f1acb4e294af24d9f7598e85163d5e1d9958ae9 by Samuel Benzaquen <sbenza@google.com>: Avoid using aliases in the SFINAE expressions to make it more compatible with MSVC. Turn on the tests in MSVC. PiperOrigin-RevId: 237261456 -- 06cf7de6250a0572ef90fa1176f742ca0451ce71 by Derek Mauro <dmauro@google.com>: Fix unused variable warning. PiperOrigin-RevId: 237108006 GitOrigin-RevId: 5dc8d7504b7c11710b19365a6582c288c8992366 Change-Id: Ife5182c80942945c4e8700844c8febb482d6ad82
2019-03-08 23:06:50 +01:00
return H::combine(hash_internal::HashSelect::template Apply<T>::Invoke(
std::move(state), value),
values...);
}
// HashStateBase::combine_contiguous()
template <typename H>
template <typename T>
H HashStateBase<H>::combine_contiguous(H state, const T* data, size_t size) {
return hash_internal::hash_range_or_bytes(std::move(state), data, size);
}
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
// HashStateBase::PiecewiseCombiner::add_buffer()
template <typename H>
H PiecewiseCombiner::add_buffer(H state, const unsigned char* data,
size_t size) {
if (position_ + size < PiecewiseChunkSize()) {
// This partial chunk does not fill our existing buffer
memcpy(buf_ + position_, data, size);
position_ += size;
Export of internal Abseil changes -- 7f6c15aadc4d97e217dd446518dbb4fdc86b36a3 by Derek Mauro <dmauro@google.com>: Upgrade GCC automated testing to use GCC 9.2 and Cmake 3.16.2 PiperOrigin-RevId: 288488783 -- a978cee848d3cf65b0826c981bfd81022fc36660 by Abseil Team <absl-team@google.com>: Removing formatting traits that were only used internally. ON_CALL/EXPECT_CALL do a sufficient job here. PiperOrigin-RevId: 288386509 -- fdec6f40293d5883220f1f0ea1261f7c5b60a66e by Derek Mauro <dmauro@google.com>: Upgrade MacOS tests to use Bazel 2.0.0 PiperOrigin-RevId: 288373298 -- 465865c4123e9481ab50ea0527e92b39519704dd by Derek Mauro <dmauro@google.com>: Changes to support GCC 9 * Fix several -Wredundant-move warnings * Remove FlatHashMap.Any test, which basically doesn't work on any platform any more (see https://cplusplus.github.io/LWG/lwg-active.html#3121) * Fix a constant sign-compare warning * Conditionally compile out the PoisonHash test which doesn't build PiperOrigin-RevId: 288360204 -- 57c4bb07fc58e7dd2a04f3c45027aab5ecaccf25 by Andy Soffer <asoffer@google.com>: Deflaking MockingBitGen test. Because MockingBitGen can return random values, it is inherently flaky. For log-unifrom, 2040 is a common enough value that tests failed unreasonably frequently. Replacing it with a significantly larger value so as to be much less common. 50000 is a good choice because it is (tied for) the least likely to occur randomly from this distribution, but is still in the distribution. PiperOrigin-RevId: 288360112 -- 86f38e4109899d972de353b1c556c018cfe37956 by Matt Calabrese <calabrese@google.com>: Remove construction tests for the internal `CompressedTuple<std::any>` instantiation. This was not guaranteed to work for the reasons that `std::tuple<std::any>` copy construction does not actually work by standard specification (some implementations introduce workarounds for this). In GCC9, `CompressedTuple<std::any>` and `std::tuple<std::any>` both fail for the same reasons, and a proper "fix" requires updating `std::any`, which is out of our control. PiperOrigin-RevId: 288351977 GitOrigin-RevId: 7f6c15aadc4d97e217dd446518dbb4fdc86b36a3 Change-Id: I5d5c62bd297dc0ff1f2970ff076bb5cd088a7e4c
2020-01-07 15:56:49 +01:00
return state;
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
}
Export of internal Abseil changes -- a3e58c1870a9626039f4d178d2d599319bd9f8a8 by Matt Kulukundis <kfm@google.com>: Allow MakeCordFromExternal to take a zero arg releaser. PiperOrigin-RevId: 298650274 -- 01897c4a9bb99f3dc329a794019498ad345ddebd by Samuel Benzaquen <sbenza@google.com>: Reduce library bloat for absl::Flag by moving the definition of base virtual functions to a .cc file. This removes the duplicate symbols in user translation units and has the side effect of moving the vtable definition too (re key function) PiperOrigin-RevId: 298617920 -- 190f0d3782c63aed01046886d7fbc1be5bca2de9 by Derek Mauro <dmauro@google.com>: Import GitHub #596: Unbreak stacktrace code for UWP apps PiperOrigin-RevId: 298600834 -- cd5cf6f8c87b35b85a9584e94da2a99057345b73 by Gennadiy Rozental <rogeeff@google.com>: Use union of heap allocated pointer, one word atomic and two word atomic to represent flags value. Any type T, which is trivially copy-able and with with sizeof(T) <= 8, will be stored in atomic int64_t. Any type T, which is trivially copy-able and with with 8 < sizeof(T) <= 16, will be stored in atomic AlignedTwoWords. We also introducing value storage type to distinguish these cases. PiperOrigin-RevId: 298497200 -- f8fe7bd53bfed601f002f521e34ab4bc083fc28b by Matthew Brown <matthewbr@google.com>: Ensure a deep copy and proper equality on absl::Status::ErasePayload PiperOrigin-RevId: 298482742 -- a5c9ccddf4b04f444e3f7e27dbc14faf1fcb5373 by Gennadiy Rozental <rogeeff@google.com>: Change ChunkIterator implementation to use fixed capacity collection of CordRep*. We can now assume that depth never exceeds 91. That makes comparison operator exception safe. I've tested that with this CL we do not observe an overhead of chunk_end. Compiler optimized this iterator completely. PiperOrigin-RevId: 298458472 -- 327ea5e8910bc388b03389c730763f9823abfce5 by Abseil Team <absl-team@google.com>: Minor cleanups in b-tree code: - Rename some variables: fix issues of different param names between definition/declaration, move away from `x` as a default meaningless variable name. - Make init_leaf/init_internal be non-static methods (they already take the node as the first parameter). - In internal_emplace/try_shrink, update root/rightmost the same way as in insert_unique/insert_multi. - Replace a TODO with a comment. PiperOrigin-RevId: 298432836 -- 8020ce9ec8558ee712d9733ae3d660ac1d3ffe1a by Abseil Team <absl-team@google.com>: Guard against unnecessary copy in case the buffer is empty. This is important in cases were the user is explicitly tuning their chunks to match PiecewiseChunkSize(). PiperOrigin-RevId: 298366044 -- 89324441d1c0c697c90ba7d8fc63639805fcaa9d by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 298219363 GitOrigin-RevId: a3e58c1870a9626039f4d178d2d599319bd9f8a8 Change-Id: I28dffc684b6fd0292b94807b88ec6664d5d0e183
2020-03-03 20:22:10 +01:00
// If the buffer is partially filled we need to complete the buffer
// and hash it.
if (position_ != 0) {
const size_t bytes_needed = PiecewiseChunkSize() - position_;
memcpy(buf_ + position_, data, bytes_needed);
state = H::combine_contiguous(std::move(state), buf_, PiecewiseChunkSize());
data += bytes_needed;
size -= bytes_needed;
}
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
// Hash whatever chunks we can without copying
while (size >= PiecewiseChunkSize()) {
state = H::combine_contiguous(std::move(state), data, PiecewiseChunkSize());
data += PiecewiseChunkSize();
size -= PiecewiseChunkSize();
}
// Fill the buffer with the remainder
memcpy(buf_, data, size);
position_ = size;
Export of internal Abseil changes -- 7f6c15aadc4d97e217dd446518dbb4fdc86b36a3 by Derek Mauro <dmauro@google.com>: Upgrade GCC automated testing to use GCC 9.2 and Cmake 3.16.2 PiperOrigin-RevId: 288488783 -- a978cee848d3cf65b0826c981bfd81022fc36660 by Abseil Team <absl-team@google.com>: Removing formatting traits that were only used internally. ON_CALL/EXPECT_CALL do a sufficient job here. PiperOrigin-RevId: 288386509 -- fdec6f40293d5883220f1f0ea1261f7c5b60a66e by Derek Mauro <dmauro@google.com>: Upgrade MacOS tests to use Bazel 2.0.0 PiperOrigin-RevId: 288373298 -- 465865c4123e9481ab50ea0527e92b39519704dd by Derek Mauro <dmauro@google.com>: Changes to support GCC 9 * Fix several -Wredundant-move warnings * Remove FlatHashMap.Any test, which basically doesn't work on any platform any more (see https://cplusplus.github.io/LWG/lwg-active.html#3121) * Fix a constant sign-compare warning * Conditionally compile out the PoisonHash test which doesn't build PiperOrigin-RevId: 288360204 -- 57c4bb07fc58e7dd2a04f3c45027aab5ecaccf25 by Andy Soffer <asoffer@google.com>: Deflaking MockingBitGen test. Because MockingBitGen can return random values, it is inherently flaky. For log-unifrom, 2040 is a common enough value that tests failed unreasonably frequently. Replacing it with a significantly larger value so as to be much less common. 50000 is a good choice because it is (tied for) the least likely to occur randomly from this distribution, but is still in the distribution. PiperOrigin-RevId: 288360112 -- 86f38e4109899d972de353b1c556c018cfe37956 by Matt Calabrese <calabrese@google.com>: Remove construction tests for the internal `CompressedTuple<std::any>` instantiation. This was not guaranteed to work for the reasons that `std::tuple<std::any>` copy construction does not actually work by standard specification (some implementations introduce workarounds for this). In GCC9, `CompressedTuple<std::any>` and `std::tuple<std::any>` both fail for the same reasons, and a proper "fix" requires updating `std::any`, which is out of our control. PiperOrigin-RevId: 288351977 GitOrigin-RevId: 7f6c15aadc4d97e217dd446518dbb4fdc86b36a3 Change-Id: I5d5c62bd297dc0ff1f2970ff076bb5cd088a7e4c
2020-01-07 15:56:49 +01:00
return state;
Export of internal Abseil changes -- 074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>: nit: Add return info for StrCat PiperOrigin-RevId: 278647298 -- d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>: Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress. PiperOrigin-RevId: 278440548 -- 445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>: ResetThreadIdentity does not need to clear identity->waiter_state. ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is only called by CreateThreadIdentity. CreateThreadIdentity calls PerThreadSem::Init, which initializes identity->waiter_state, immediately after calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear identity->waiter_state. PiperOrigin-RevId: 278429844 -- c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>: Delete the f->header.magic check in LowLevelAlloc::Free(). The f->header.magic check in LowLevelAlloc::Free() is redundant, because AddToFreeList() will immediately perform the same check. Also fix a typo in the comment that documents the lock requirements for Next(). The comment should say "L >= arena->mu", which is equivalent to EXCLUSIVE_LOCKS_REQUIRED(arena->mu). NOTE: LowLevelAlloc::Free() performs the f->header.magic check without holding the arena lock. This may have caused the TSAN data race warning reported in bug 143697235. PiperOrigin-RevId: 278414140 -- 5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>: Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise. PiperOrigin-RevId: 278388902 GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 18:49:15 +01:00
}
// HashStateBase::PiecewiseCombiner::finalize()
template <typename H>
H PiecewiseCombiner::finalize(H state) {
// Hash the remainder left in the buffer, which may be empty
return H::combine_contiguous(std::move(state), buf_, position_);
}
} // namespace hash_internal
Export of internal Abseil changes -- c99f979ad34f155fbeeea69b88bdc7458d89a21c by Derek Mauro <dmauro@google.com>: Remove a floating point division by zero test. This isn't testing behavior related to the library, and MSVC warns about it in opt mode. PiperOrigin-RevId: 285220804 -- 68b015491f0dbf1ab547994673281abd1f34cd4b by Gennadiy Rozental <rogeeff@google.com>: This CL introduces following changes to the class FlagImpl: * We eliminate the CommandLineFlagLocks struct. Instead callback guard and callback function are combined into a single CallbackData struct, while primary data lock is stored separately. * CallbackData member of class FlagImpl is initially set to be nullptr and is only allocated and initialized when a flag's callback is being set. For most flags we do not pay for the extra space and extra absl::Mutex now. * Primary data guard is stored in data_guard_ data member. This is a properly aligned character buffer of necessary size. During initialization of the flag we construct absl::Mutex in this space using placement new call. * We now avoid extra value copy after successful attempt to parse value out of string. Instead we swap flag's current value with tentative value we just produced. PiperOrigin-RevId: 285132636 -- ed45d118fb818969eb13094cf7827c885dfc562c by Tom Manshreck <shreck@google.com>: Change null-term* (and nul-term*) to NUL-term* in comments PiperOrigin-RevId: 285036610 -- 729619017944db895ce8d6d29c1995aa2e5628a5 by Derek Mauro <dmauro@google.com>: Use the Posix implementation of thread identity on MinGW. Some versions of MinGW suffer from thread_local bugs. PiperOrigin-RevId: 285022920 -- 39a25493503c76885bc3254c28f66a251c5b5bb0 by Greg Falcon <gfalcon@google.com>: Implementation detail change. Add further ABSL_NAMESPACE_BEGIN and _END annotation macros to files in Abseil. PiperOrigin-RevId: 285012012 GitOrigin-RevId: c99f979ad34f155fbeeea69b88bdc7458d89a21c Change-Id: I4c85d3704e45d11a9ac50d562f39640a6adbedc1
2019-12-12 19:36:03 +01:00
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_HASH_INTERNAL_HASH_H_