tvl-depot/absl/container/internal/raw_hash_set.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
//
// http://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.
//
// An open-addressing
// hashtable with quadratic probing.
//
// This is a low level hashtable on top of which different interfaces can be
// implemented, like flat_hash_set, node_hash_set, string_hash_set, etc.
//
// The table interface is similar to that of std::unordered_set. Notable
// differences are that most member functions support heterogeneous keys when
// BOTH the hash and eq functions are marked as transparent. They do so by
// providing a typedef called `is_transparent`.
//
// When heterogeneous lookup is enabled, functions that take key_type act as if
// they have an overload set like:
//
// iterator find(const key_type& key);
// template <class K>
// iterator find(const K& key);
//
// size_type erase(const key_type& key);
// template <class K>
// size_type erase(const K& key);
//
// std::pair<iterator, iterator> equal_range(const key_type& key);
// template <class K>
// std::pair<iterator, iterator> equal_range(const K& key);
//
// When heterogeneous lookup is disabled, only the explicit `key_type` overloads
// exist.
//
// find() also supports passing the hash explicitly:
//
// iterator find(const key_type& key, size_t hash);
// template <class U>
// iterator find(const U& key, size_t hash);
//
// In addition the pointer to element and iterator stability guarantees are
// weaker: all iterators and pointers are invalidated after a new element is
// inserted.
//
// IMPLEMENTATION DETAILS
//
// The table stores elements inline in a slot array. In addition to the slot
// array the table maintains some control state per slot. The extra state is one
// byte per slot and stores empty or deleted marks, or alternatively 7 bits from
// the hash of an occupied slot. The table is split into logical groups of
// slots, like so:
//
// Group 1 Group 2 Group 3
// +---------------+---------------+---------------+
// | | | | | | | | | | | | | | | | | | | | | | | | |
// +---------------+---------------+---------------+
//
// On lookup the hash is split into two parts:
// - H2: 7 bits (those stored in the control bytes)
// - H1: the rest of the bits
// The groups are probed using H1. For each group the slots are matched to H2 in
// parallel. Because H2 is 7 bits (128 states) and the number of slots per group
// is low (8 or 16) in almost all cases a match in H2 is also a lookup hit.
//
// On insert, once the right group is found (as in lookup), its slots are
// filled in order.
//
// On erase a slot is cleared. In case the group did not have any empty slots
// before the erase, the erased slot is marked as deleted.
//
// Groups without empty slots (but maybe with deleted slots) extend the probe
// sequence. The probing algorithm is quadratic. Given N the number of groups,
// the probing function for the i'th probe is:
//
// P(0) = H1 % N
//
// P(i) = (P(i - 1) + i) % N
//
// This probing function guarantees that after N probes, all the groups of the
// table will be probed exactly once.
#ifndef ABSL_CONTAINER_INTERNAL_RAW_HASH_SET_H_
#define ABSL_CONTAINER_INTERNAL_RAW_HASH_SET_H_
#ifndef SWISSTABLE_HAVE_SSE2
Export of internal Abseil changes. -- ee19e203eca970ff88e8f25ce4e19c32e143b988 by Jon Cohen <cohenjon@google.com>: Exception safety testing no longer uses absl::optional PiperOrigin-RevId: 220336204 -- 460666eb0b316a8b4aeedc589644d53b05251bd1 by Derek Mauro <dmauro@google.com>: Rework SwissTable SSE2 support - Use SSE2 on MSVC when available https://github.com/abseil/abseil-cpp/issues/210 - Emulate _mm_cmpgt_epi8 with other SSE2 instructions when using -funsigned-char under GCC https://github.com/abseil/abseil-cpp/issues/209 PiperOrigin-RevId: 220312351 -- 1f4318ecedf8d539b7b698eb803d613ad6b69278 by Abseil Team <absl-team@google.com>: Change CollectPerfectRatios to use 10 trials to smooth out the outliers in the sample. PiperOrigin-RevId: 220286579 -- 6755abc2673553a7f578bb29c6e9ca8d991bc9c8 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 220274307 -- 8645b6187329ebf0aaf3c2de2888ba44466cd879 by Abseil Team <absl-team@google.com>: * #endif for a header guard should reference the guard macro in a comment PiperOrigin-RevId: 220206868 -- 3987a7ad11319230910931cd2468b60b3fd1b85c by Gennadiy Civil <misterg@google.com>: Internal Change PiperOrigin-RevId: 220136674 -- cc908c1db2ee0d4523dc813e33f600583bb986c5 by Abseil Team <absl-team@google.com>: absl: fix backoff logic in SpinLockWait There are 3 bugs in loop variable handling: 1. It starts with 0, but AbslInternalSpinLockDelay ignores loop == 0. So it does not actually wait when it should. 2. loop is incremented after successful state changes, but it should not (why would be increase backoff delay after that?). 3. loop is incremented after CAS failures, but it should not (why would be increase backoff delay after that?). Use the same handling of loop as used in SpinLock. PiperOrigin-RevId: 220136079 -- a0a1c6ef5910ebd28e07215d7df03cc0da0b3eed by Abseil Team <absl-team@google.com>: absl: relax unnecessarily strong memory ordering in SpinLock::SlowLock We don't need to acquire visibility over anything when setting kSpinLockSleeper. Replace the confusing and unnecessarily strong memory order with relaxed. PiperOrigin-RevId: 220023380 -- c50858b51af28b9fca1a62616324f85f3e84ea74 by Tom Manshreck <shreck@google.com>: Update comments in flat_hash_map, node_hash_{set, map} and the containers developer guide PiperOrigin-RevId: 219938692 -- e87b7d1a5f61e165b1c44d3b16d8d967197cdfce by CJ Johnson <johnsoncj@google.com>: Rearranges the public methods of InlinedVector and cleans up the comments PiperOrigin-RevId: 219896257 -- f3234c466f792e0fc4bfd21fc7919dba5e679375 by CJ Johnson <johnsoncj@google.com>: Adds branch prediction to exceptional early exit cases of inlined vector's API PiperOrigin-RevId: 219887173 -- 4dfccf1a81ca0425912d3da25a8470f78c532ce4 by CJ Johnson <johnsoncj@google.com>: Fixes the InlinedVector public interface to use the allocator type references instead of assuming the type Also cleans up some cruft in formatting and comments PiperOrigin-RevId: 219878876 -- 4bb6a2b892abb10bd6a424db7e94ed8640802470 by Tom Manshreck <shreck@google.com>: Add comments on constructor and assignment operator support to flat_hash_set PiperOrigin-RevId: 219825338 -- c23f973e2f7f4feea0da36bf8a9c3f8a8954bb74 by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 219823847 GitOrigin-RevId: ee19e203eca970ff88e8f25ce4e19c32e143b988 Change-Id: I288c927ca481dc57340420dbb4c278a05cf15e83
2018-11-06 22:01:25 +01:00
#if defined(__SSE2__) || \
(defined(_MSC_VER) && \
(defined(_M_X64) || (defined(_M_IX86) && _M_IX86_FP >= 2)))
#define SWISSTABLE_HAVE_SSE2 1
#else
#define SWISSTABLE_HAVE_SSE2 0
#endif
#endif
#ifndef SWISSTABLE_HAVE_SSSE3
#ifdef __SSSE3__
#define SWISSTABLE_HAVE_SSSE3 1
#else
#define SWISSTABLE_HAVE_SSSE3 0
#endif
#endif
#if SWISSTABLE_HAVE_SSSE3 && !SWISSTABLE_HAVE_SSE2
#error "Bad configuration!"
#endif
#if SWISSTABLE_HAVE_SSE2
Export of internal Abseil changes. -- ee19e203eca970ff88e8f25ce4e19c32e143b988 by Jon Cohen <cohenjon@google.com>: Exception safety testing no longer uses absl::optional PiperOrigin-RevId: 220336204 -- 460666eb0b316a8b4aeedc589644d53b05251bd1 by Derek Mauro <dmauro@google.com>: Rework SwissTable SSE2 support - Use SSE2 on MSVC when available https://github.com/abseil/abseil-cpp/issues/210 - Emulate _mm_cmpgt_epi8 with other SSE2 instructions when using -funsigned-char under GCC https://github.com/abseil/abseil-cpp/issues/209 PiperOrigin-RevId: 220312351 -- 1f4318ecedf8d539b7b698eb803d613ad6b69278 by Abseil Team <absl-team@google.com>: Change CollectPerfectRatios to use 10 trials to smooth out the outliers in the sample. PiperOrigin-RevId: 220286579 -- 6755abc2673553a7f578bb29c6e9ca8d991bc9c8 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 220274307 -- 8645b6187329ebf0aaf3c2de2888ba44466cd879 by Abseil Team <absl-team@google.com>: * #endif for a header guard should reference the guard macro in a comment PiperOrigin-RevId: 220206868 -- 3987a7ad11319230910931cd2468b60b3fd1b85c by Gennadiy Civil <misterg@google.com>: Internal Change PiperOrigin-RevId: 220136674 -- cc908c1db2ee0d4523dc813e33f600583bb986c5 by Abseil Team <absl-team@google.com>: absl: fix backoff logic in SpinLockWait There are 3 bugs in loop variable handling: 1. It starts with 0, but AbslInternalSpinLockDelay ignores loop == 0. So it does not actually wait when it should. 2. loop is incremented after successful state changes, but it should not (why would be increase backoff delay after that?). 3. loop is incremented after CAS failures, but it should not (why would be increase backoff delay after that?). Use the same handling of loop as used in SpinLock. PiperOrigin-RevId: 220136079 -- a0a1c6ef5910ebd28e07215d7df03cc0da0b3eed by Abseil Team <absl-team@google.com>: absl: relax unnecessarily strong memory ordering in SpinLock::SlowLock We don't need to acquire visibility over anything when setting kSpinLockSleeper. Replace the confusing and unnecessarily strong memory order with relaxed. PiperOrigin-RevId: 220023380 -- c50858b51af28b9fca1a62616324f85f3e84ea74 by Tom Manshreck <shreck@google.com>: Update comments in flat_hash_map, node_hash_{set, map} and the containers developer guide PiperOrigin-RevId: 219938692 -- e87b7d1a5f61e165b1c44d3b16d8d967197cdfce by CJ Johnson <johnsoncj@google.com>: Rearranges the public methods of InlinedVector and cleans up the comments PiperOrigin-RevId: 219896257 -- f3234c466f792e0fc4bfd21fc7919dba5e679375 by CJ Johnson <johnsoncj@google.com>: Adds branch prediction to exceptional early exit cases of inlined vector's API PiperOrigin-RevId: 219887173 -- 4dfccf1a81ca0425912d3da25a8470f78c532ce4 by CJ Johnson <johnsoncj@google.com>: Fixes the InlinedVector public interface to use the allocator type references instead of assuming the type Also cleans up some cruft in formatting and comments PiperOrigin-RevId: 219878876 -- 4bb6a2b892abb10bd6a424db7e94ed8640802470 by Tom Manshreck <shreck@google.com>: Add comments on constructor and assignment operator support to flat_hash_set PiperOrigin-RevId: 219825338 -- c23f973e2f7f4feea0da36bf8a9c3f8a8954bb74 by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 219823847 GitOrigin-RevId: ee19e203eca970ff88e8f25ce4e19c32e143b988 Change-Id: I288c927ca481dc57340420dbb4c278a05cf15e83
2018-11-06 22:01:25 +01:00
#include <emmintrin.h>
#endif
#if SWISSTABLE_HAVE_SSSE3
#include <tmmintrin.h>
#endif
#include <algorithm>
#include <cmath>
#include <cstdint>
#include <cstring>
#include <iterator>
#include <limits>
#include <memory>
#include <tuple>
#include <type_traits>
#include <utility>
#include "absl/base/internal/bits.h"
#include "absl/base/internal/endian.h"
#include "absl/base/port.h"
#include "absl/container/internal/compressed_tuple.h"
#include "absl/container/internal/container_memory.h"
#include "absl/container/internal/hash_policy_traits.h"
#include "absl/container/internal/hashtable_debug_hooks.h"
#include "absl/container/internal/layout.h"
#include "absl/memory/memory.h"
#include "absl/meta/type_traits.h"
#include "absl/types/optional.h"
#include "absl/utility/utility.h"
namespace absl {
namespace container_internal {
template <size_t Width>
class probe_seq {
public:
probe_seq(size_t hash, size_t mask) {
assert(((mask + 1) & mask) == 0 && "not a mask");
mask_ = mask;
offset_ = hash & mask_;
}
size_t offset() const { return offset_; }
size_t offset(size_t i) const { return (offset_ + i) & mask_; }
void next() {
index_ += Width;
offset_ += index_;
offset_ &= mask_;
}
// 0-based probe index. The i-th probe in the probe sequence.
size_t index() const { return index_; }
private:
size_t mask_;
size_t offset_;
size_t index_ = 0;
};
template <class ContainerKey, class Hash, class Eq>
struct RequireUsableKey {
template <class PassedKey, class... Args>
std::pair<
decltype(std::declval<const Hash&>()(std::declval<const PassedKey&>())),
decltype(std::declval<const Eq&>()(std::declval<const ContainerKey&>(),
std::declval<const PassedKey&>()))>*
operator()(const PassedKey&, const Args&...) const;
};
template <class E, class Policy, class Hash, class Eq, class... Ts>
struct IsDecomposable : std::false_type {};
template <class Policy, class Hash, class Eq, class... Ts>
struct IsDecomposable<
absl::void_t<decltype(
Policy::apply(RequireUsableKey<typename Policy::key_type, Hash, Eq>(),
std::declval<Ts>()...))>,
Policy, Hash, Eq, Ts...> : std::true_type {};
template <class, class = void>
struct IsTransparent : std::false_type {};
template <class T>
struct IsTransparent<T, absl::void_t<typename T::is_transparent>>
: std::true_type {};
// TODO(alkis): Switch to std::is_nothrow_swappable when gcc/clang supports it.
template <class T>
constexpr bool IsNoThrowSwappable() {
using std::swap;
return noexcept(swap(std::declval<T&>(), std::declval<T&>()));
}
template <typename T>
int TrailingZeros(T x) {
Export of internal Abseil changes. -- 178e7a9a76fc8fcd6df6335b59139cbe644a16b9 by Jon Cohen <cohenjon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 220523164 -- 59ef14fe7034a3148f1e9cef1f128b8ca264b444 by Jon Cohen <cohenjon@google.com>: Don't assume how much std::vector's constructors allocate in InlinedVector's test for scoped_allocator_adaptor support. PiperOrigin-RevId: 220464683 -- 6f8351be43a44a8f10bf20612b2cc744a4a911c7 by Jon Cohen <cohenjon@google.com>: Add VS Code and some Bazel output files to absl/.gitignore PiperOrigin-RevId: 220464362 -- 43fac22f8af6b6ed55309a784a9d25d837393d0e by Abseil Team <absl-team@google.com>: absl: fix SpinLock::EncodeWaitCycles If a thread has ever observed or set kSpinLockSleeper, it must never leave 0 in kWaitTimeMask because at this point it is expected to wake subsequent threads. Current calculations in EncodeWaitCycles can result in 0 in kWaitTimeMask and lead to missed wakeups. This is mostly theoretical today, because the futex call needs to finish within 128 cycles (futex can return immediately without waiting, but 128 cycles still look too low for this). But this can well fire in future if we bump granularity and/or threshold for recording contention. Use kSpinLockSleeper instead of 0. PiperOrigin-RevId: 220463123 -- def9b7e3d45c99d68cc52a4429256116d7f421f2 by Abseil Team <absl-team@google.com>: absl: optimize SpinLock::SlowLock Currently we record contention even after the first initial spin. This leads to several performance issues: 1. If we succeed in acquiring the lock after the initial spin, overall wait time can be within tens/hundreds of nanoseconds. Recording such low wait time looks completely unnecessary and excessive. From some point of view this is not even a wait, because we did not sleep. And, for example, Mutex does not record contention in this case. In majority of cases the lock should be acquired exactly during the initial spin, yet we still go through full overhead of submitting contention. 2. Whenever a thread submits contention it also calls FUTEX_WAKE (there is no way to understand if it's necessary or not when wait value is stored in the lock). So if there are just 2 threads and a brief contention, the second thread will still call FUTEX_WAKE which is completely unnecessary overhead. Don't record contention after the initial spin wait. FWIW this also removes 2 CycleClock::Now calls and EncodeWaitCycles from the common hot path. PiperOrigin-RevId: 220379972 -- 75b0c0cb214de904ea622f81ec3f4eabdc8695b0 by Derek Mauro <dmauro@google.com>: Supress MSVC warnings in raw_hash_set's use of TrailingZeros and LeadingZeros. https://github.com/abseil/abseil-cpp/issues/208 PiperOrigin-RevId: 220372204 GitOrigin-RevId: 178e7a9a76fc8fcd6df6335b59139cbe644a16b9 Change-Id: I3a66af4e050810a3274e45d4e055b2aa19ffba1b
2018-11-07 22:52:16 +01:00
return sizeof(T) == 8 ? base_internal::CountTrailingZerosNonZero64(
static_cast<uint64_t>(x))
: base_internal::CountTrailingZerosNonZero32(
static_cast<uint32_t>(x));
}
template <typename T>
int LeadingZeros(T x) {
Export of internal Abseil changes. -- 178e7a9a76fc8fcd6df6335b59139cbe644a16b9 by Jon Cohen <cohenjon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 220523164 -- 59ef14fe7034a3148f1e9cef1f128b8ca264b444 by Jon Cohen <cohenjon@google.com>: Don't assume how much std::vector's constructors allocate in InlinedVector's test for scoped_allocator_adaptor support. PiperOrigin-RevId: 220464683 -- 6f8351be43a44a8f10bf20612b2cc744a4a911c7 by Jon Cohen <cohenjon@google.com>: Add VS Code and some Bazel output files to absl/.gitignore PiperOrigin-RevId: 220464362 -- 43fac22f8af6b6ed55309a784a9d25d837393d0e by Abseil Team <absl-team@google.com>: absl: fix SpinLock::EncodeWaitCycles If a thread has ever observed or set kSpinLockSleeper, it must never leave 0 in kWaitTimeMask because at this point it is expected to wake subsequent threads. Current calculations in EncodeWaitCycles can result in 0 in kWaitTimeMask and lead to missed wakeups. This is mostly theoretical today, because the futex call needs to finish within 128 cycles (futex can return immediately without waiting, but 128 cycles still look too low for this). But this can well fire in future if we bump granularity and/or threshold for recording contention. Use kSpinLockSleeper instead of 0. PiperOrigin-RevId: 220463123 -- def9b7e3d45c99d68cc52a4429256116d7f421f2 by Abseil Team <absl-team@google.com>: absl: optimize SpinLock::SlowLock Currently we record contention even after the first initial spin. This leads to several performance issues: 1. If we succeed in acquiring the lock after the initial spin, overall wait time can be within tens/hundreds of nanoseconds. Recording such low wait time looks completely unnecessary and excessive. From some point of view this is not even a wait, because we did not sleep. And, for example, Mutex does not record contention in this case. In majority of cases the lock should be acquired exactly during the initial spin, yet we still go through full overhead of submitting contention. 2. Whenever a thread submits contention it also calls FUTEX_WAKE (there is no way to understand if it's necessary or not when wait value is stored in the lock). So if there are just 2 threads and a brief contention, the second thread will still call FUTEX_WAKE which is completely unnecessary overhead. Don't record contention after the initial spin wait. FWIW this also removes 2 CycleClock::Now calls and EncodeWaitCycles from the common hot path. PiperOrigin-RevId: 220379972 -- 75b0c0cb214de904ea622f81ec3f4eabdc8695b0 by Derek Mauro <dmauro@google.com>: Supress MSVC warnings in raw_hash_set's use of TrailingZeros and LeadingZeros. https://github.com/abseil/abseil-cpp/issues/208 PiperOrigin-RevId: 220372204 GitOrigin-RevId: 178e7a9a76fc8fcd6df6335b59139cbe644a16b9 Change-Id: I3a66af4e050810a3274e45d4e055b2aa19ffba1b
2018-11-07 22:52:16 +01:00
return sizeof(T) == 8
? base_internal::CountLeadingZeros64(static_cast<uint64_t>(x))
: base_internal::CountLeadingZeros32(static_cast<uint32_t>(x));
}
// An abstraction over a bitmask. It provides an easy way to iterate through the
// indexes of the set bits of a bitmask. When Shift=0 (platforms with SSE),
// this is a true bitmask. On non-SSE, platforms the arithematic used to
// emulate the SSE behavior works in bytes (Shift=3) and leaves each bytes as
// either 0x00 or 0x80.
//
// For example:
// for (int i : BitMask<uint32_t, 16>(0x5)) -> yields 0, 2
// for (int i : BitMask<uint64_t, 8, 3>(0x0000000080800000)) -> yields 2, 3
template <class T, int SignificantBits, int Shift = 0>
class BitMask {
static_assert(std::is_unsigned<T>::value, "");
static_assert(Shift == 0 || Shift == 3, "");
public:
// These are useful for unit tests (gunit).
using value_type = int;
using iterator = BitMask;
using const_iterator = BitMask;
explicit BitMask(T mask) : mask_(mask) {}
BitMask& operator++() {
mask_ &= (mask_ - 1);
return *this;
}
explicit operator bool() const { return mask_ != 0; }
int operator*() const { return LowestBitSet(); }
int LowestBitSet() const {
return container_internal::TrailingZeros(mask_) >> Shift;
}
int HighestBitSet() const {
return (sizeof(T) * CHAR_BIT - container_internal::LeadingZeros(mask_) -
1) >>
Shift;
}
BitMask begin() const { return *this; }
BitMask end() const { return BitMask(0); }
int TrailingZeros() const {
return container_internal::TrailingZeros(mask_) >> Shift;
}
int LeadingZeros() const {
constexpr int total_significant_bits = SignificantBits << Shift;
constexpr int extra_bits = sizeof(T) * 8 - total_significant_bits;
return container_internal::LeadingZeros(mask_ << extra_bits) >> Shift;
}
private:
friend bool operator==(const BitMask& a, const BitMask& b) {
return a.mask_ == b.mask_;
}
friend bool operator!=(const BitMask& a, const BitMask& b) {
return a.mask_ != b.mask_;
}
T mask_;
};
using ctrl_t = signed char;
using h2_t = uint8_t;
// The values here are selected for maximum performance. See the static asserts
// below for details.
enum Ctrl : ctrl_t {
kEmpty = -128, // 0b10000000
kDeleted = -2, // 0b11111110
kSentinel = -1, // 0b11111111
};
static_assert(
kEmpty & kDeleted & kSentinel & 0x80,
"Special markers need to have the MSB to make checking for them efficient");
static_assert(kEmpty < kSentinel && kDeleted < kSentinel,
"kEmpty and kDeleted must be smaller than kSentinel to make the "
"SIMD test of IsEmptyOrDeleted() efficient");
static_assert(kSentinel == -1,
"kSentinel must be -1 to elide loading it from memory into SIMD "
"registers (pcmpeqd xmm, xmm)");
static_assert(kEmpty == -128,
"kEmpty must be -128 to make the SIMD check for its "
"existence efficient (psignb xmm, xmm)");
static_assert(~kEmpty & ~kDeleted & kSentinel & 0x7F,
"kEmpty and kDeleted must share an unset bit that is not shared "
"by kSentinel to make the scalar test for MatchEmptyOrDeleted() "
"efficient");
static_assert(kDeleted == -2,
"kDeleted must be -2 to make the implementation of "
"ConvertSpecialToEmptyAndFullToDeleted efficient");
// A single block of empty control bytes for tables without any slots allocated.
// This enables removing a branch in the hot path of find().
inline ctrl_t* EmptyGroup() {
alignas(16) static constexpr ctrl_t empty_group[] = {
kSentinel, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty,
kEmpty, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty, kEmpty};
return const_cast<ctrl_t*>(empty_group);
}
// Mixes a randomly generated per-process seed with `hash` and `ctrl` to
// randomize insertion order within groups.
bool ShouldInsertBackwards(size_t hash, ctrl_t* ctrl);
// Returns a hash seed.
//
// The seed consists of the ctrl_ pointer, which adds enough entropy to ensure
// non-determinism of iteration order in most cases.
inline size_t HashSeed(const ctrl_t* ctrl) {
// The low bits of the pointer have little or no entropy because of
// alignment. We shift the pointer to try to use higher entropy bits. A
// good number seems to be 12 bits, because that aligns with page size.
return reinterpret_cast<uintptr_t>(ctrl) >> 12;
}
inline size_t H1(size_t hash, const ctrl_t* ctrl) {
return (hash >> 7) ^ HashSeed(ctrl);
}
inline ctrl_t H2(size_t hash) { return hash & 0x7F; }
inline bool IsEmpty(ctrl_t c) { return c == kEmpty; }
inline bool IsFull(ctrl_t c) { return c >= 0; }
inline bool IsDeleted(ctrl_t c) { return c == kDeleted; }
inline bool IsEmptyOrDeleted(ctrl_t c) { return c < kSentinel; }
#if SWISSTABLE_HAVE_SSE2
Export of internal Abseil changes. -- ee19e203eca970ff88e8f25ce4e19c32e143b988 by Jon Cohen <cohenjon@google.com>: Exception safety testing no longer uses absl::optional PiperOrigin-RevId: 220336204 -- 460666eb0b316a8b4aeedc589644d53b05251bd1 by Derek Mauro <dmauro@google.com>: Rework SwissTable SSE2 support - Use SSE2 on MSVC when available https://github.com/abseil/abseil-cpp/issues/210 - Emulate _mm_cmpgt_epi8 with other SSE2 instructions when using -funsigned-char under GCC https://github.com/abseil/abseil-cpp/issues/209 PiperOrigin-RevId: 220312351 -- 1f4318ecedf8d539b7b698eb803d613ad6b69278 by Abseil Team <absl-team@google.com>: Change CollectPerfectRatios to use 10 trials to smooth out the outliers in the sample. PiperOrigin-RevId: 220286579 -- 6755abc2673553a7f578bb29c6e9ca8d991bc9c8 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 220274307 -- 8645b6187329ebf0aaf3c2de2888ba44466cd879 by Abseil Team <absl-team@google.com>: * #endif for a header guard should reference the guard macro in a comment PiperOrigin-RevId: 220206868 -- 3987a7ad11319230910931cd2468b60b3fd1b85c by Gennadiy Civil <misterg@google.com>: Internal Change PiperOrigin-RevId: 220136674 -- cc908c1db2ee0d4523dc813e33f600583bb986c5 by Abseil Team <absl-team@google.com>: absl: fix backoff logic in SpinLockWait There are 3 bugs in loop variable handling: 1. It starts with 0, but AbslInternalSpinLockDelay ignores loop == 0. So it does not actually wait when it should. 2. loop is incremented after successful state changes, but it should not (why would be increase backoff delay after that?). 3. loop is incremented after CAS failures, but it should not (why would be increase backoff delay after that?). Use the same handling of loop as used in SpinLock. PiperOrigin-RevId: 220136079 -- a0a1c6ef5910ebd28e07215d7df03cc0da0b3eed by Abseil Team <absl-team@google.com>: absl: relax unnecessarily strong memory ordering in SpinLock::SlowLock We don't need to acquire visibility over anything when setting kSpinLockSleeper. Replace the confusing and unnecessarily strong memory order with relaxed. PiperOrigin-RevId: 220023380 -- c50858b51af28b9fca1a62616324f85f3e84ea74 by Tom Manshreck <shreck@google.com>: Update comments in flat_hash_map, node_hash_{set, map} and the containers developer guide PiperOrigin-RevId: 219938692 -- e87b7d1a5f61e165b1c44d3b16d8d967197cdfce by CJ Johnson <johnsoncj@google.com>: Rearranges the public methods of InlinedVector and cleans up the comments PiperOrigin-RevId: 219896257 -- f3234c466f792e0fc4bfd21fc7919dba5e679375 by CJ Johnson <johnsoncj@google.com>: Adds branch prediction to exceptional early exit cases of inlined vector's API PiperOrigin-RevId: 219887173 -- 4dfccf1a81ca0425912d3da25a8470f78c532ce4 by CJ Johnson <johnsoncj@google.com>: Fixes the InlinedVector public interface to use the allocator type references instead of assuming the type Also cleans up some cruft in formatting and comments PiperOrigin-RevId: 219878876 -- 4bb6a2b892abb10bd6a424db7e94ed8640802470 by Tom Manshreck <shreck@google.com>: Add comments on constructor and assignment operator support to flat_hash_set PiperOrigin-RevId: 219825338 -- c23f973e2f7f4feea0da36bf8a9c3f8a8954bb74 by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 219823847 GitOrigin-RevId: ee19e203eca970ff88e8f25ce4e19c32e143b988 Change-Id: I288c927ca481dc57340420dbb4c278a05cf15e83
2018-11-06 22:01:25 +01:00
// https://github.com/abseil/abseil-cpp/issues/209
// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87853
// _mm_cmpgt_epi8 is broken under GCC with -funsigned-char
// Work around this by using the portable implementation of Group
// when using -funsigned-char under GCC.
inline __m128i _mm_cmpgt_epi8_fixed(__m128i a, __m128i b) {
#if defined(__GNUC__) && !defined(__clang__)
if (std::is_unsigned<char>::value) {
const __m128i mask = _mm_set1_epi8(0x80);
const __m128i diff = _mm_subs_epi8(b, a);
return _mm_cmpeq_epi8(_mm_and_si128(diff, mask), mask);
}
#endif
return _mm_cmpgt_epi8(a, b);
}
struct GroupSse2Impl {
static constexpr size_t kWidth = 16; // the number of slots per group
explicit GroupSse2Impl(const ctrl_t* pos) {
ctrl = _mm_loadu_si128(reinterpret_cast<const __m128i*>(pos));
}
// Returns a bitmask representing the positions of slots that match hash.
BitMask<uint32_t, kWidth> Match(h2_t hash) const {
auto match = _mm_set1_epi8(hash);
return BitMask<uint32_t, kWidth>(
_mm_movemask_epi8(_mm_cmpeq_epi8(match, ctrl)));
}
// Returns a bitmask representing the positions of empty slots.
BitMask<uint32_t, kWidth> MatchEmpty() const {
#if SWISSTABLE_HAVE_SSSE3
// This only works because kEmpty is -128.
return BitMask<uint32_t, kWidth>(
_mm_movemask_epi8(_mm_sign_epi8(ctrl, ctrl)));
#else
return Match(kEmpty);
#endif
}
// Returns a bitmask representing the positions of empty or deleted slots.
BitMask<uint32_t, kWidth> MatchEmptyOrDeleted() const {
auto special = _mm_set1_epi8(kSentinel);
return BitMask<uint32_t, kWidth>(
Export of internal Abseil changes. -- ee19e203eca970ff88e8f25ce4e19c32e143b988 by Jon Cohen <cohenjon@google.com>: Exception safety testing no longer uses absl::optional PiperOrigin-RevId: 220336204 -- 460666eb0b316a8b4aeedc589644d53b05251bd1 by Derek Mauro <dmauro@google.com>: Rework SwissTable SSE2 support - Use SSE2 on MSVC when available https://github.com/abseil/abseil-cpp/issues/210 - Emulate _mm_cmpgt_epi8 with other SSE2 instructions when using -funsigned-char under GCC https://github.com/abseil/abseil-cpp/issues/209 PiperOrigin-RevId: 220312351 -- 1f4318ecedf8d539b7b698eb803d613ad6b69278 by Abseil Team <absl-team@google.com>: Change CollectPerfectRatios to use 10 trials to smooth out the outliers in the sample. PiperOrigin-RevId: 220286579 -- 6755abc2673553a7f578bb29c6e9ca8d991bc9c8 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 220274307 -- 8645b6187329ebf0aaf3c2de2888ba44466cd879 by Abseil Team <absl-team@google.com>: * #endif for a header guard should reference the guard macro in a comment PiperOrigin-RevId: 220206868 -- 3987a7ad11319230910931cd2468b60b3fd1b85c by Gennadiy Civil <misterg@google.com>: Internal Change PiperOrigin-RevId: 220136674 -- cc908c1db2ee0d4523dc813e33f600583bb986c5 by Abseil Team <absl-team@google.com>: absl: fix backoff logic in SpinLockWait There are 3 bugs in loop variable handling: 1. It starts with 0, but AbslInternalSpinLockDelay ignores loop == 0. So it does not actually wait when it should. 2. loop is incremented after successful state changes, but it should not (why would be increase backoff delay after that?). 3. loop is incremented after CAS failures, but it should not (why would be increase backoff delay after that?). Use the same handling of loop as used in SpinLock. PiperOrigin-RevId: 220136079 -- a0a1c6ef5910ebd28e07215d7df03cc0da0b3eed by Abseil Team <absl-team@google.com>: absl: relax unnecessarily strong memory ordering in SpinLock::SlowLock We don't need to acquire visibility over anything when setting kSpinLockSleeper. Replace the confusing and unnecessarily strong memory order with relaxed. PiperOrigin-RevId: 220023380 -- c50858b51af28b9fca1a62616324f85f3e84ea74 by Tom Manshreck <shreck@google.com>: Update comments in flat_hash_map, node_hash_{set, map} and the containers developer guide PiperOrigin-RevId: 219938692 -- e87b7d1a5f61e165b1c44d3b16d8d967197cdfce by CJ Johnson <johnsoncj@google.com>: Rearranges the public methods of InlinedVector and cleans up the comments PiperOrigin-RevId: 219896257 -- f3234c466f792e0fc4bfd21fc7919dba5e679375 by CJ Johnson <johnsoncj@google.com>: Adds branch prediction to exceptional early exit cases of inlined vector's API PiperOrigin-RevId: 219887173 -- 4dfccf1a81ca0425912d3da25a8470f78c532ce4 by CJ Johnson <johnsoncj@google.com>: Fixes the InlinedVector public interface to use the allocator type references instead of assuming the type Also cleans up some cruft in formatting and comments PiperOrigin-RevId: 219878876 -- 4bb6a2b892abb10bd6a424db7e94ed8640802470 by Tom Manshreck <shreck@google.com>: Add comments on constructor and assignment operator support to flat_hash_set PiperOrigin-RevId: 219825338 -- c23f973e2f7f4feea0da36bf8a9c3f8a8954bb74 by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 219823847 GitOrigin-RevId: ee19e203eca970ff88e8f25ce4e19c32e143b988 Change-Id: I288c927ca481dc57340420dbb4c278a05cf15e83
2018-11-06 22:01:25 +01:00
_mm_movemask_epi8(_mm_cmpgt_epi8_fixed(special, ctrl)));
}
// Returns the number of trailing empty or deleted elements in the group.
uint32_t CountLeadingEmptyOrDeleted() const {
auto special = _mm_set1_epi8(kSentinel);
Export of internal Abseil changes. -- ee19e203eca970ff88e8f25ce4e19c32e143b988 by Jon Cohen <cohenjon@google.com>: Exception safety testing no longer uses absl::optional PiperOrigin-RevId: 220336204 -- 460666eb0b316a8b4aeedc589644d53b05251bd1 by Derek Mauro <dmauro@google.com>: Rework SwissTable SSE2 support - Use SSE2 on MSVC when available https://github.com/abseil/abseil-cpp/issues/210 - Emulate _mm_cmpgt_epi8 with other SSE2 instructions when using -funsigned-char under GCC https://github.com/abseil/abseil-cpp/issues/209 PiperOrigin-RevId: 220312351 -- 1f4318ecedf8d539b7b698eb803d613ad6b69278 by Abseil Team <absl-team@google.com>: Change CollectPerfectRatios to use 10 trials to smooth out the outliers in the sample. PiperOrigin-RevId: 220286579 -- 6755abc2673553a7f578bb29c6e9ca8d991bc9c8 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 220274307 -- 8645b6187329ebf0aaf3c2de2888ba44466cd879 by Abseil Team <absl-team@google.com>: * #endif for a header guard should reference the guard macro in a comment PiperOrigin-RevId: 220206868 -- 3987a7ad11319230910931cd2468b60b3fd1b85c by Gennadiy Civil <misterg@google.com>: Internal Change PiperOrigin-RevId: 220136674 -- cc908c1db2ee0d4523dc813e33f600583bb986c5 by Abseil Team <absl-team@google.com>: absl: fix backoff logic in SpinLockWait There are 3 bugs in loop variable handling: 1. It starts with 0, but AbslInternalSpinLockDelay ignores loop == 0. So it does not actually wait when it should. 2. loop is incremented after successful state changes, but it should not (why would be increase backoff delay after that?). 3. loop is incremented after CAS failures, but it should not (why would be increase backoff delay after that?). Use the same handling of loop as used in SpinLock. PiperOrigin-RevId: 220136079 -- a0a1c6ef5910ebd28e07215d7df03cc0da0b3eed by Abseil Team <absl-team@google.com>: absl: relax unnecessarily strong memory ordering in SpinLock::SlowLock We don't need to acquire visibility over anything when setting kSpinLockSleeper. Replace the confusing and unnecessarily strong memory order with relaxed. PiperOrigin-RevId: 220023380 -- c50858b51af28b9fca1a62616324f85f3e84ea74 by Tom Manshreck <shreck@google.com>: Update comments in flat_hash_map, node_hash_{set, map} and the containers developer guide PiperOrigin-RevId: 219938692 -- e87b7d1a5f61e165b1c44d3b16d8d967197cdfce by CJ Johnson <johnsoncj@google.com>: Rearranges the public methods of InlinedVector and cleans up the comments PiperOrigin-RevId: 219896257 -- f3234c466f792e0fc4bfd21fc7919dba5e679375 by CJ Johnson <johnsoncj@google.com>: Adds branch prediction to exceptional early exit cases of inlined vector's API PiperOrigin-RevId: 219887173 -- 4dfccf1a81ca0425912d3da25a8470f78c532ce4 by CJ Johnson <johnsoncj@google.com>: Fixes the InlinedVector public interface to use the allocator type references instead of assuming the type Also cleans up some cruft in formatting and comments PiperOrigin-RevId: 219878876 -- 4bb6a2b892abb10bd6a424db7e94ed8640802470 by Tom Manshreck <shreck@google.com>: Add comments on constructor and assignment operator support to flat_hash_set PiperOrigin-RevId: 219825338 -- c23f973e2f7f4feea0da36bf8a9c3f8a8954bb74 by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 219823847 GitOrigin-RevId: ee19e203eca970ff88e8f25ce4e19c32e143b988 Change-Id: I288c927ca481dc57340420dbb4c278a05cf15e83
2018-11-06 22:01:25 +01:00
return TrailingZeros(
_mm_movemask_epi8(_mm_cmpgt_epi8_fixed(special, ctrl)) + 1);
}
void ConvertSpecialToEmptyAndFullToDeleted(ctrl_t* dst) const {
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
auto msbs = _mm_set1_epi8(static_cast<char>(-128));
auto x126 = _mm_set1_epi8(126);
#if SWISSTABLE_HAVE_SSSE3
auto res = _mm_or_si128(_mm_shuffle_epi8(x126, ctrl), msbs);
#else
auto zero = _mm_setzero_si128();
Export of internal Abseil changes. -- ee19e203eca970ff88e8f25ce4e19c32e143b988 by Jon Cohen <cohenjon@google.com>: Exception safety testing no longer uses absl::optional PiperOrigin-RevId: 220336204 -- 460666eb0b316a8b4aeedc589644d53b05251bd1 by Derek Mauro <dmauro@google.com>: Rework SwissTable SSE2 support - Use SSE2 on MSVC when available https://github.com/abseil/abseil-cpp/issues/210 - Emulate _mm_cmpgt_epi8 with other SSE2 instructions when using -funsigned-char under GCC https://github.com/abseil/abseil-cpp/issues/209 PiperOrigin-RevId: 220312351 -- 1f4318ecedf8d539b7b698eb803d613ad6b69278 by Abseil Team <absl-team@google.com>: Change CollectPerfectRatios to use 10 trials to smooth out the outliers in the sample. PiperOrigin-RevId: 220286579 -- 6755abc2673553a7f578bb29c6e9ca8d991bc9c8 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 220274307 -- 8645b6187329ebf0aaf3c2de2888ba44466cd879 by Abseil Team <absl-team@google.com>: * #endif for a header guard should reference the guard macro in a comment PiperOrigin-RevId: 220206868 -- 3987a7ad11319230910931cd2468b60b3fd1b85c by Gennadiy Civil <misterg@google.com>: Internal Change PiperOrigin-RevId: 220136674 -- cc908c1db2ee0d4523dc813e33f600583bb986c5 by Abseil Team <absl-team@google.com>: absl: fix backoff logic in SpinLockWait There are 3 bugs in loop variable handling: 1. It starts with 0, but AbslInternalSpinLockDelay ignores loop == 0. So it does not actually wait when it should. 2. loop is incremented after successful state changes, but it should not (why would be increase backoff delay after that?). 3. loop is incremented after CAS failures, but it should not (why would be increase backoff delay after that?). Use the same handling of loop as used in SpinLock. PiperOrigin-RevId: 220136079 -- a0a1c6ef5910ebd28e07215d7df03cc0da0b3eed by Abseil Team <absl-team@google.com>: absl: relax unnecessarily strong memory ordering in SpinLock::SlowLock We don't need to acquire visibility over anything when setting kSpinLockSleeper. Replace the confusing and unnecessarily strong memory order with relaxed. PiperOrigin-RevId: 220023380 -- c50858b51af28b9fca1a62616324f85f3e84ea74 by Tom Manshreck <shreck@google.com>: Update comments in flat_hash_map, node_hash_{set, map} and the containers developer guide PiperOrigin-RevId: 219938692 -- e87b7d1a5f61e165b1c44d3b16d8d967197cdfce by CJ Johnson <johnsoncj@google.com>: Rearranges the public methods of InlinedVector and cleans up the comments PiperOrigin-RevId: 219896257 -- f3234c466f792e0fc4bfd21fc7919dba5e679375 by CJ Johnson <johnsoncj@google.com>: Adds branch prediction to exceptional early exit cases of inlined vector's API PiperOrigin-RevId: 219887173 -- 4dfccf1a81ca0425912d3da25a8470f78c532ce4 by CJ Johnson <johnsoncj@google.com>: Fixes the InlinedVector public interface to use the allocator type references instead of assuming the type Also cleans up some cruft in formatting and comments PiperOrigin-RevId: 219878876 -- 4bb6a2b892abb10bd6a424db7e94ed8640802470 by Tom Manshreck <shreck@google.com>: Add comments on constructor and assignment operator support to flat_hash_set PiperOrigin-RevId: 219825338 -- c23f973e2f7f4feea0da36bf8a9c3f8a8954bb74 by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 219823847 GitOrigin-RevId: ee19e203eca970ff88e8f25ce4e19c32e143b988 Change-Id: I288c927ca481dc57340420dbb4c278a05cf15e83
2018-11-06 22:01:25 +01:00
auto special_mask = _mm_cmpgt_epi8_fixed(zero, ctrl);
auto res = _mm_or_si128(msbs, _mm_andnot_si128(special_mask, x126));
#endif
_mm_storeu_si128(reinterpret_cast<__m128i*>(dst), res);
}
__m128i ctrl;
};
#endif // SWISSTABLE_HAVE_SSE2
struct GroupPortableImpl {
static constexpr size_t kWidth = 8;
explicit GroupPortableImpl(const ctrl_t* pos)
: ctrl(little_endian::Load64(pos)) {}
BitMask<uint64_t, kWidth, 3> Match(h2_t hash) const {
// For the technique, see:
// http://graphics.stanford.edu/~seander/bithacks.html##ValueInWord
// (Determine if a word has a byte equal to n).
//
// Caveat: there are false positives but:
// - they only occur if there is a real match
// - they never occur on kEmpty, kDeleted, kSentinel
// - they will be handled gracefully by subsequent checks in code
//
// Example:
// v = 0x1716151413121110
// hash = 0x12
// retval = (v - lsbs) & ~v & msbs = 0x0000000080800000
constexpr uint64_t msbs = 0x8080808080808080ULL;
constexpr uint64_t lsbs = 0x0101010101010101ULL;
auto x = ctrl ^ (lsbs * hash);
return BitMask<uint64_t, kWidth, 3>((x - lsbs) & ~x & msbs);
}
BitMask<uint64_t, kWidth, 3> MatchEmpty() const {
constexpr uint64_t msbs = 0x8080808080808080ULL;
return BitMask<uint64_t, kWidth, 3>((ctrl & (~ctrl << 6)) & msbs);
}
BitMask<uint64_t, kWidth, 3> MatchEmptyOrDeleted() const {
constexpr uint64_t msbs = 0x8080808080808080ULL;
return BitMask<uint64_t, kWidth, 3>((ctrl & (~ctrl << 7)) & msbs);
}
uint32_t CountLeadingEmptyOrDeleted() const {
constexpr uint64_t gaps = 0x00FEFEFEFEFEFEFEULL;
return (TrailingZeros(((~ctrl & (ctrl >> 7)) | gaps) + 1) + 7) >> 3;
}
void ConvertSpecialToEmptyAndFullToDeleted(ctrl_t* dst) const {
constexpr uint64_t msbs = 0x8080808080808080ULL;
constexpr uint64_t lsbs = 0x0101010101010101ULL;
auto x = ctrl & msbs;
auto res = (~x + (x >> 7)) & ~lsbs;
little_endian::Store64(dst, res);
}
uint64_t ctrl;
};
Export of internal Abseil changes. -- ee19e203eca970ff88e8f25ce4e19c32e143b988 by Jon Cohen <cohenjon@google.com>: Exception safety testing no longer uses absl::optional PiperOrigin-RevId: 220336204 -- 460666eb0b316a8b4aeedc589644d53b05251bd1 by Derek Mauro <dmauro@google.com>: Rework SwissTable SSE2 support - Use SSE2 on MSVC when available https://github.com/abseil/abseil-cpp/issues/210 - Emulate _mm_cmpgt_epi8 with other SSE2 instructions when using -funsigned-char under GCC https://github.com/abseil/abseil-cpp/issues/209 PiperOrigin-RevId: 220312351 -- 1f4318ecedf8d539b7b698eb803d613ad6b69278 by Abseil Team <absl-team@google.com>: Change CollectPerfectRatios to use 10 trials to smooth out the outliers in the sample. PiperOrigin-RevId: 220286579 -- 6755abc2673553a7f578bb29c6e9ca8d991bc9c8 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 220274307 -- 8645b6187329ebf0aaf3c2de2888ba44466cd879 by Abseil Team <absl-team@google.com>: * #endif for a header guard should reference the guard macro in a comment PiperOrigin-RevId: 220206868 -- 3987a7ad11319230910931cd2468b60b3fd1b85c by Gennadiy Civil <misterg@google.com>: Internal Change PiperOrigin-RevId: 220136674 -- cc908c1db2ee0d4523dc813e33f600583bb986c5 by Abseil Team <absl-team@google.com>: absl: fix backoff logic in SpinLockWait There are 3 bugs in loop variable handling: 1. It starts with 0, but AbslInternalSpinLockDelay ignores loop == 0. So it does not actually wait when it should. 2. loop is incremented after successful state changes, but it should not (why would be increase backoff delay after that?). 3. loop is incremented after CAS failures, but it should not (why would be increase backoff delay after that?). Use the same handling of loop as used in SpinLock. PiperOrigin-RevId: 220136079 -- a0a1c6ef5910ebd28e07215d7df03cc0da0b3eed by Abseil Team <absl-team@google.com>: absl: relax unnecessarily strong memory ordering in SpinLock::SlowLock We don't need to acquire visibility over anything when setting kSpinLockSleeper. Replace the confusing and unnecessarily strong memory order with relaxed. PiperOrigin-RevId: 220023380 -- c50858b51af28b9fca1a62616324f85f3e84ea74 by Tom Manshreck <shreck@google.com>: Update comments in flat_hash_map, node_hash_{set, map} and the containers developer guide PiperOrigin-RevId: 219938692 -- e87b7d1a5f61e165b1c44d3b16d8d967197cdfce by CJ Johnson <johnsoncj@google.com>: Rearranges the public methods of InlinedVector and cleans up the comments PiperOrigin-RevId: 219896257 -- f3234c466f792e0fc4bfd21fc7919dba5e679375 by CJ Johnson <johnsoncj@google.com>: Adds branch prediction to exceptional early exit cases of inlined vector's API PiperOrigin-RevId: 219887173 -- 4dfccf1a81ca0425912d3da25a8470f78c532ce4 by CJ Johnson <johnsoncj@google.com>: Fixes the InlinedVector public interface to use the allocator type references instead of assuming the type Also cleans up some cruft in formatting and comments PiperOrigin-RevId: 219878876 -- 4bb6a2b892abb10bd6a424db7e94ed8640802470 by Tom Manshreck <shreck@google.com>: Add comments on constructor and assignment operator support to flat_hash_set PiperOrigin-RevId: 219825338 -- c23f973e2f7f4feea0da36bf8a9c3f8a8954bb74 by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 219823847 GitOrigin-RevId: ee19e203eca970ff88e8f25ce4e19c32e143b988 Change-Id: I288c927ca481dc57340420dbb4c278a05cf15e83
2018-11-06 22:01:25 +01:00
#if SWISSTABLE_HAVE_SSE2
using Group = GroupSse2Impl;
#else
using Group = GroupPortableImpl;
#endif
template <class Policy, class Hash, class Eq, class Alloc>
class raw_hash_set;
inline bool IsValidCapacity(size_t n) {
return ((n + 1) & n) == 0 && n >= Group::kWidth - 1;
}
// PRECONDITION:
// IsValidCapacity(capacity)
// ctrl[capacity] == kSentinel
// ctrl[i] != kSentinel for all i < capacity
// Applies mapping for every byte in ctrl:
// DELETED -> EMPTY
// EMPTY -> EMPTY
// FULL -> DELETED
inline void ConvertDeletedToEmptyAndFullToDeleted(
ctrl_t* ctrl, size_t capacity) {
assert(ctrl[capacity] == kSentinel);
assert(IsValidCapacity(capacity));
for (ctrl_t* pos = ctrl; pos != ctrl + capacity + 1; pos += Group::kWidth) {
Group{pos}.ConvertSpecialToEmptyAndFullToDeleted(pos);
}
// Copy the cloned ctrl bytes.
std::memcpy(ctrl + capacity + 1, ctrl, Group::kWidth);
ctrl[capacity] = kSentinel;
}
// Rounds up the capacity to the next power of 2 minus 1 and ensures it is
// greater or equal to Group::kWidth - 1.
inline size_t NormalizeCapacity(size_t n) {
constexpr size_t kMinCapacity = Group::kWidth - 1;
return n <= kMinCapacity
? kMinCapacity
Export of internal Abseil changes. -- ba4dd47492748bd630462eb68b7959037fc6a11a by Abseil Team <absl-team@google.com>: Work around nvcc 9.0 compiler bug for open-source Tensorflow build. With the current implementation, when I (unintentionally and transitively) include absl/types/optional.h in a CUDA compilation unit, I get the following nvcc error message: INFO: From Compiling tensorflow/core/kernels/crop_and_resize_op_gpu.cu.cc: external/com_google_absl/absl/types/optional.h: In member function 'void absl::optional_internal::optional_data_dtor_base<T, <anonymous> >::destruct()': external/com_google_absl/absl/types/optional.h:185:50: error: '__T0' was not declared in this scope data_.~T(); I've also seen similar compilation failures online, for flat_hash_map: https://devtalk.nvidia.com/default/topic/1042599/nvcc-preprocessor-bug-causes-compilation-failure/ The bug is always around unnamed template parameters. Therefore, the workaround is to make them named. PiperOrigin-RevId: 219208288 -- dad2f40cb2e8d5017660985ef6fb57f3c3cdcc80 by CJ Johnson <johnsoncj@google.com>: Adds internal macros for catching and throwing unknown exception types PiperOrigin-RevId: 219207362 -- 0a9840328d2d86e8420b853435fdbf1f7a19d931 by Abseil Team <absl-team@google.com>: Fix typo in mutex.h comments. PiperOrigin-RevId: 219199397 -- 0d576dc7597564210bfdf91518075064756f0bf4 by Matt Calabrese <calabrese@google.com>: Internal change. PiperOrigin-RevId: 219185475 -- 66be156095571959fb19a76da8ad0b53ec37658e by Abseil Team <absl-team@google.com>: Fix alignment conformance for VS 2017 >= 15.8 (fix #193) PiperOrigin-RevId: 219129894 -- a6e1825a12587945f8194677ccfdcaba6f7aad1d by Abseil Team <absl-team@google.com>: Reapply PR #173 PiperOrigin-RevId: 219129361 -- cf72ade4881b25acc6ccaea468f69793a0fdce32 by Abseil Team <absl-team@google.com>: Update .gitignore PiperOrigin-RevId: 219127495 -- 0537490c6348a2cb489abe15638928ac5aa6982a by Jon Cohen <cohenjon@google.com>: Small refactor and reformat of error messages from the exception safety test framework. PiperOrigin-RevId: 218927773 -- 4c556ca45fa25698ad12002a00c713aeceefab73 by CJ Johnson <johnsoncj@google.com>: Updates the inlined vector swap tests to check for number of moves that took place if available PiperOrigin-RevId: 218900777 -- dcbfda0021a1e6dfa9586986b1269c06ec394053 by Mark Barolak <mbar@google.com>: Add parens around calls to std::numeric_limits<>::min and std::numeric_limits<>::max to prevent compilation errors on Windows platforms where min and max are defined as macros. PiperOrigin-RevId: 218888700 GitOrigin-RevId: ba4dd47492748bd630462eb68b7959037fc6a11a Change-Id: I0e393958eb8cb501b85f6114979f6d4d86ed996c
2018-10-29 23:53:34 +01:00
: (std::numeric_limits<size_t>::max)() >> LeadingZeros(n);
}
// The node_handle concept from C++17.
// We specialize node_handle for sets and maps. node_handle_base holds the
// common API of both.
template <typename Policy, typename Alloc>
class node_handle_base {
protected:
using PolicyTraits = hash_policy_traits<Policy>;
using slot_type = typename PolicyTraits::slot_type;
public:
using allocator_type = Alloc;
constexpr node_handle_base() {}
node_handle_base(node_handle_base&& other) noexcept {
*this = std::move(other);
}
~node_handle_base() { destroy(); }
node_handle_base& operator=(node_handle_base&& other) {
destroy();
if (!other.empty()) {
alloc_ = other.alloc_;
PolicyTraits::transfer(alloc(), slot(), other.slot());
other.reset();
}
return *this;
}
bool empty() const noexcept { return !alloc_; }
explicit operator bool() const noexcept { return !empty(); }
allocator_type get_allocator() const { return *alloc_; }
protected:
template <typename, typename, typename, typename>
friend class raw_hash_set;
node_handle_base(const allocator_type& a, slot_type* s) : alloc_(a) {
PolicyTraits::transfer(alloc(), slot(), s);
}
void destroy() {
if (!empty()) {
PolicyTraits::destroy(alloc(), slot());
reset();
}
}
void reset() {
assert(alloc_.has_value());
alloc_ = absl::nullopt;
}
slot_type* slot() const {
assert(!empty());
return reinterpret_cast<slot_type*>(std::addressof(slot_space_));
}
allocator_type* alloc() { return std::addressof(*alloc_); }
private:
absl::optional<allocator_type> alloc_;
mutable absl::aligned_storage_t<sizeof(slot_type), alignof(slot_type)>
slot_space_;
};
// For sets.
template <typename Policy, typename Alloc, typename = void>
class node_handle : public node_handle_base<Policy, Alloc> {
using Base = typename node_handle::node_handle_base;
public:
using value_type = typename Base::PolicyTraits::value_type;
constexpr node_handle() {}
value_type& value() const {
return Base::PolicyTraits::element(this->slot());
}
private:
template <typename, typename, typename, typename>
friend class raw_hash_set;
node_handle(const Alloc& a, typename Base::slot_type* s) : Base(a, s) {}
};
// For maps.
template <typename Policy, typename Alloc>
class node_handle<Policy, Alloc, absl::void_t<typename Policy::mapped_type>>
: public node_handle_base<Policy, Alloc> {
using Base = typename node_handle::node_handle_base;
public:
using key_type = typename Policy::key_type;
using mapped_type = typename Policy::mapped_type;
constexpr node_handle() {}
auto key() const -> decltype(Base::PolicyTraits::key(this->slot())) {
return Base::PolicyTraits::key(this->slot());
}
mapped_type& mapped() const {
return Base::PolicyTraits::value(
&Base::PolicyTraits::element(this->slot()));
}
private:
template <typename, typename, typename, typename>
friend class raw_hash_set;
node_handle(const Alloc& a, typename Base::slot_type* s) : Base(a, s) {}
};
// Implement the insert_return_type<> concept of C++17.
template <class Iterator, class NodeType>
struct insert_return_type {
Iterator position;
bool inserted;
NodeType node;
};
// Helper trait to allow or disallow arbitrary keys when the hash and
// eq functions are transparent.
// It is very important that the inner template is an alias and that the type it
// produces is not a dependent type. Otherwise, type deduction would fail.
template <bool is_transparent>
struct KeyArg {
// Transparent. Forward `K`.
template <typename K, typename key_type>
using type = K;
};
template <>
struct KeyArg<false> {
// Not transparent. Always use `key_type`.
template <typename K, typename key_type>
using type = key_type;
};
// Policy: a policy defines how to perform different operations on
// the slots of the hashtable (see hash_policy_traits.h for the full interface
// of policy).
//
// Hash: a (possibly polymorphic) functor that hashes keys of the hashtable. The
// functor should accept a key and return size_t as hash. For best performance
// it is important that the hash function provides high entropy across all bits
// of the hash.
//
// Eq: a (possibly polymorphic) functor that compares two keys for equality. It
// should accept two (of possibly different type) keys and return a bool: true
// if they are equal, false if they are not. If two keys compare equal, then
// their hash values as defined by Hash MUST be equal.
//
// Allocator: an Allocator [http://devdocs.io/cpp/concept/allocator] with which
// the storage of the hashtable will be allocated and the elements will be
// constructed and destroyed.
template <class Policy, class Hash, class Eq, class Alloc>
class raw_hash_set {
using PolicyTraits = hash_policy_traits<Policy>;
using KeyArgImpl = container_internal::KeyArg<IsTransparent<Eq>::value &&
IsTransparent<Hash>::value>;
public:
using init_type = typename PolicyTraits::init_type;
using key_type = typename PolicyTraits::key_type;
// TODO(sbenza): Hide slot_type as it is an implementation detail. Needs user
// code fixes!
using slot_type = typename PolicyTraits::slot_type;
using allocator_type = Alloc;
using size_type = size_t;
using difference_type = ptrdiff_t;
using hasher = Hash;
using key_equal = Eq;
using policy_type = Policy;
using value_type = typename PolicyTraits::value_type;
using reference = value_type&;
using const_reference = const value_type&;
using pointer = typename absl::allocator_traits<
allocator_type>::template rebind_traits<value_type>::pointer;
using const_pointer = typename absl::allocator_traits<
allocator_type>::template rebind_traits<value_type>::const_pointer;
// Alias used for heterogeneous lookup functions.
// `key_arg<K>` evaluates to `K` when the functors are transparent and to
// `key_type` otherwise. It permits template argument deduction on `K` for the
// transparent case.
template <class K>
using key_arg = typename KeyArgImpl::template type<K, key_type>;
private:
// Give an early error when key_type is not hashable/eq.
auto KeyTypeCanBeHashed(const Hash& h, const key_type& k) -> decltype(h(k));
auto KeyTypeCanBeEq(const Eq& eq, const key_type& k) -> decltype(eq(k, k));
using Layout = absl::container_internal::Layout<ctrl_t, slot_type>;
static Layout MakeLayout(size_t capacity) {
assert(IsValidCapacity(capacity));
return Layout(capacity + Group::kWidth + 1, capacity);
}
using AllocTraits = absl::allocator_traits<allocator_type>;
using SlotAlloc = typename absl::allocator_traits<
allocator_type>::template rebind_alloc<slot_type>;
using SlotAllocTraits = typename absl::allocator_traits<
allocator_type>::template rebind_traits<slot_type>;
static_assert(std::is_lvalue_reference<reference>::value,
"Policy::element() must return a reference");
template <typename T>
struct SameAsElementReference
: std::is_same<typename std::remove_cv<
typename std::remove_reference<reference>::type>::type,
typename std::remove_cv<
typename std::remove_reference<T>::type>::type> {};
// An enabler for insert(T&&): T must be convertible to init_type or be the
// same as [cv] value_type [ref].
// Note: we separate SameAsElementReference into its own type to avoid using
// reference unless we need to. MSVC doesn't seem to like it in some
// cases.
template <class T>
using RequiresInsertable = typename std::enable_if<
absl::disjunction<std::is_convertible<T, init_type>,
SameAsElementReference<T>>::value,
int>::type;
// RequiresNotInit is a workaround for gcc prior to 7.1.
// See https://godbolt.org/g/Y4xsUh.
template <class T>
using RequiresNotInit =
typename std::enable_if<!std::is_same<T, init_type>::value, int>::type;
template <class... Ts>
using IsDecomposable = IsDecomposable<void, PolicyTraits, Hash, Eq, Ts...>;
public:
static_assert(std::is_same<pointer, value_type*>::value,
"Allocators with custom pointer types are not supported");
static_assert(std::is_same<const_pointer, const value_type*>::value,
"Allocators with custom pointer types are not supported");
class iterator {
friend class raw_hash_set;
public:
using iterator_category = std::forward_iterator_tag;
using value_type = typename raw_hash_set::value_type;
using reference =
absl::conditional_t<PolicyTraits::constant_iterators::value,
const value_type&, value_type&>;
using pointer = absl::remove_reference_t<reference>*;
using difference_type = typename raw_hash_set::difference_type;
iterator() {}
// PRECONDITION: not an end() iterator.
reference operator*() const { return PolicyTraits::element(slot_); }
// PRECONDITION: not an end() iterator.
pointer operator->() const { return &operator*(); }
// PRECONDITION: not an end() iterator.
iterator& operator++() {
++ctrl_;
++slot_;
skip_empty_or_deleted();
return *this;
}
// PRECONDITION: not an end() iterator.
iterator operator++(int) {
auto tmp = *this;
++*this;
return tmp;
}
friend bool operator==(const iterator& a, const iterator& b) {
return a.ctrl_ == b.ctrl_;
}
friend bool operator!=(const iterator& a, const iterator& b) {
return !(a == b);
}
private:
iterator(ctrl_t* ctrl) : ctrl_(ctrl) {} // for end()
iterator(ctrl_t* ctrl, slot_type* slot) : ctrl_(ctrl), slot_(slot) {}
void skip_empty_or_deleted() {
while (IsEmptyOrDeleted(*ctrl_)) {
// ctrl is not necessarily aligned to Group::kWidth. It is also likely
// to read past the space for ctrl bytes and into slots. This is ok
// because ctrl has sizeof() == 1 and slot has sizeof() >= 1 so there
// is no way to read outside the combined slot array.
uint32_t shift = Group{ctrl_}.CountLeadingEmptyOrDeleted();
ctrl_ += shift;
slot_ += shift;
}
}
ctrl_t* ctrl_ = nullptr;
slot_type* slot_;
};
class const_iterator {
friend class raw_hash_set;
public:
using iterator_category = typename iterator::iterator_category;
using value_type = typename raw_hash_set::value_type;
using reference = typename raw_hash_set::const_reference;
using pointer = typename raw_hash_set::const_pointer;
using difference_type = typename raw_hash_set::difference_type;
const_iterator() {}
// Implicit construction from iterator.
const_iterator(iterator i) : inner_(std::move(i)) {}
reference operator*() const { return *inner_; }
pointer operator->() const { return inner_.operator->(); }
const_iterator& operator++() {
++inner_;
return *this;
}
const_iterator operator++(int) { return inner_++; }
friend bool operator==(const const_iterator& a, const const_iterator& b) {
return a.inner_ == b.inner_;
}
friend bool operator!=(const const_iterator& a, const const_iterator& b) {
return !(a == b);
}
private:
const_iterator(const ctrl_t* ctrl, const slot_type* slot)
: inner_(const_cast<ctrl_t*>(ctrl), const_cast<slot_type*>(slot)) {}
iterator inner_;
};
using node_type = container_internal::node_handle<Policy, Alloc>;
raw_hash_set() noexcept(
std::is_nothrow_default_constructible<hasher>::value&&
std::is_nothrow_default_constructible<key_equal>::value&&
std::is_nothrow_default_constructible<allocator_type>::value) {}
explicit raw_hash_set(size_t bucket_count, const hasher& hash = hasher(),
const key_equal& eq = key_equal(),
const allocator_type& alloc = allocator_type())
: ctrl_(EmptyGroup()), settings_(0, hash, eq, alloc) {
if (bucket_count) {
capacity_ = NormalizeCapacity(bucket_count);
growth_left() = static_cast<size_t>(capacity_ * kMaxLoadFactor);
initialize_slots();
}
}
raw_hash_set(size_t bucket_count, const hasher& hash,
const allocator_type& alloc)
: raw_hash_set(bucket_count, hash, key_equal(), alloc) {}
raw_hash_set(size_t bucket_count, const allocator_type& alloc)
: raw_hash_set(bucket_count, hasher(), key_equal(), alloc) {}
explicit raw_hash_set(const allocator_type& alloc)
: raw_hash_set(0, hasher(), key_equal(), alloc) {}
template <class InputIter>
raw_hash_set(InputIter first, InputIter last, size_t bucket_count = 0,
const hasher& hash = hasher(), const key_equal& eq = key_equal(),
const allocator_type& alloc = allocator_type())
: raw_hash_set(bucket_count, hash, eq, alloc) {
insert(first, last);
}
template <class InputIter>
raw_hash_set(InputIter first, InputIter last, size_t bucket_count,
const hasher& hash, const allocator_type& alloc)
: raw_hash_set(first, last, bucket_count, hash, key_equal(), alloc) {}
template <class InputIter>
raw_hash_set(InputIter first, InputIter last, size_t bucket_count,
const allocator_type& alloc)
: raw_hash_set(first, last, bucket_count, hasher(), key_equal(), alloc) {}
template <class InputIter>
raw_hash_set(InputIter first, InputIter last, const allocator_type& alloc)
: raw_hash_set(first, last, 0, hasher(), key_equal(), alloc) {}
// Instead of accepting std::initializer_list<value_type> as the first
// argument like std::unordered_set<value_type> does, we have two overloads
// that accept std::initializer_list<T> and std::initializer_list<init_type>.
// This is advantageous for performance.
//
// // Turns {"abc", "def"} into std::initializer_list<std::string>, then copies
// // the strings into the set.
// std::unordered_set<std::string> s = {"abc", "def"};
//
// // Turns {"abc", "def"} into std::initializer_list<const char*>, then
// // copies the strings into the set.
// absl::flat_hash_set<std::string> s = {"abc", "def"};
//
// The same trick is used in insert().
//
// The enabler is necessary to prevent this constructor from triggering where
// the copy constructor is meant to be called.
//
// absl::flat_hash_set<int> a, b{a};
//
// RequiresNotInit<T> is a workaround for gcc prior to 7.1.
template <class T, RequiresNotInit<T> = 0, RequiresInsertable<T> = 0>
raw_hash_set(std::initializer_list<T> init, size_t bucket_count = 0,
const hasher& hash = hasher(), const key_equal& eq = key_equal(),
const allocator_type& alloc = allocator_type())
: raw_hash_set(init.begin(), init.end(), bucket_count, hash, eq, alloc) {}
raw_hash_set(std::initializer_list<init_type> init, size_t bucket_count = 0,
const hasher& hash = hasher(), const key_equal& eq = key_equal(),
const allocator_type& alloc = allocator_type())
: raw_hash_set(init.begin(), init.end(), bucket_count, hash, eq, alloc) {}
template <class T, RequiresNotInit<T> = 0, RequiresInsertable<T> = 0>
raw_hash_set(std::initializer_list<T> init, size_t bucket_count,
const hasher& hash, const allocator_type& alloc)
: raw_hash_set(init, bucket_count, hash, key_equal(), alloc) {}
raw_hash_set(std::initializer_list<init_type> init, size_t bucket_count,
const hasher& hash, const allocator_type& alloc)
: raw_hash_set(init, bucket_count, hash, key_equal(), alloc) {}
template <class T, RequiresNotInit<T> = 0, RequiresInsertable<T> = 0>
raw_hash_set(std::initializer_list<T> init, size_t bucket_count,
const allocator_type& alloc)
: raw_hash_set(init, bucket_count, hasher(), key_equal(), alloc) {}
raw_hash_set(std::initializer_list<init_type> init, size_t bucket_count,
const allocator_type& alloc)
: raw_hash_set(init, bucket_count, hasher(), key_equal(), alloc) {}
template <class T, RequiresNotInit<T> = 0, RequiresInsertable<T> = 0>
raw_hash_set(std::initializer_list<T> init, const allocator_type& alloc)
: raw_hash_set(init, 0, hasher(), key_equal(), alloc) {}
raw_hash_set(std::initializer_list<init_type> init,
const allocator_type& alloc)
: raw_hash_set(init, 0, hasher(), key_equal(), alloc) {}
raw_hash_set(const raw_hash_set& that)
: raw_hash_set(that, AllocTraits::select_on_container_copy_construction(
that.alloc_ref())) {}
raw_hash_set(const raw_hash_set& that, const allocator_type& a)
: raw_hash_set(0, that.hash_ref(), that.eq_ref(), a) {
reserve(that.size());
// Because the table is guaranteed to be empty, we can do something faster
// than a full `insert`.
for (const auto& v : that) {
const size_t hash = PolicyTraits::apply(HashElement{hash_ref()}, v);
const size_t i = find_first_non_full(hash);
set_ctrl(i, H2(hash));
emplace_at(i, v);
}
size_ = that.size();
growth_left() -= that.size();
}
raw_hash_set(raw_hash_set&& that) noexcept(
std::is_nothrow_copy_constructible<hasher>::value&&
std::is_nothrow_copy_constructible<key_equal>::value&&
std::is_nothrow_copy_constructible<allocator_type>::value)
: ctrl_(absl::exchange(that.ctrl_, EmptyGroup())),
slots_(absl::exchange(that.slots_, nullptr)),
size_(absl::exchange(that.size_, 0)),
capacity_(absl::exchange(that.capacity_, 0)),
// Hash, equality and allocator are copied instead of moved because
// `that` must be left valid. If Hash is std::function<Key>, moving it
// would create a nullptr functor that cannot be called.
settings_(that.settings_) {
// growth_left was copied above, reset the one from `that`.
that.growth_left() = 0;
}
raw_hash_set(raw_hash_set&& that, const allocator_type& a)
: ctrl_(EmptyGroup()),
slots_(nullptr),
size_(0),
capacity_(0),
settings_(0, that.hash_ref(), that.eq_ref(), a) {
if (a == that.alloc_ref()) {
std::swap(ctrl_, that.ctrl_);
std::swap(slots_, that.slots_);
std::swap(size_, that.size_);
std::swap(capacity_, that.capacity_);
std::swap(growth_left(), that.growth_left());
} else {
reserve(that.size());
// Note: this will copy elements of dense_set and unordered_set instead of
// moving them. This can be fixed if it ever becomes an issue.
for (auto& elem : that) insert(std::move(elem));
}
}
raw_hash_set& operator=(const raw_hash_set& that) {
raw_hash_set tmp(that,
AllocTraits::propagate_on_container_copy_assignment::value
? that.alloc_ref()
: alloc_ref());
swap(tmp);
return *this;
}
raw_hash_set& operator=(raw_hash_set&& that) noexcept(
absl::allocator_traits<allocator_type>::is_always_equal::value&&
std::is_nothrow_move_assignable<hasher>::value&&
std::is_nothrow_move_assignable<key_equal>::value) {
// TODO(sbenza): We should only use the operations from the noexcept clause
// to make sure we actually adhere to that contract.
return move_assign(
std::move(that),
typename AllocTraits::propagate_on_container_move_assignment());
}
~raw_hash_set() { destroy_slots(); }
iterator begin() {
auto it = iterator_at(0);
it.skip_empty_or_deleted();
return it;
}
iterator end() { return {ctrl_ + capacity_}; }
const_iterator begin() const {
return const_cast<raw_hash_set*>(this)->begin();
}
const_iterator end() const { return const_cast<raw_hash_set*>(this)->end(); }
const_iterator cbegin() const { return begin(); }
const_iterator cend() const { return end(); }
bool empty() const { return !size(); }
size_t size() const { return size_; }
size_t capacity() const { return capacity_; }
Export of internal Abseil changes. -- ba4dd47492748bd630462eb68b7959037fc6a11a by Abseil Team <absl-team@google.com>: Work around nvcc 9.0 compiler bug for open-source Tensorflow build. With the current implementation, when I (unintentionally and transitively) include absl/types/optional.h in a CUDA compilation unit, I get the following nvcc error message: INFO: From Compiling tensorflow/core/kernels/crop_and_resize_op_gpu.cu.cc: external/com_google_absl/absl/types/optional.h: In member function 'void absl::optional_internal::optional_data_dtor_base<T, <anonymous> >::destruct()': external/com_google_absl/absl/types/optional.h:185:50: error: '__T0' was not declared in this scope data_.~T(); I've also seen similar compilation failures online, for flat_hash_map: https://devtalk.nvidia.com/default/topic/1042599/nvcc-preprocessor-bug-causes-compilation-failure/ The bug is always around unnamed template parameters. Therefore, the workaround is to make them named. PiperOrigin-RevId: 219208288 -- dad2f40cb2e8d5017660985ef6fb57f3c3cdcc80 by CJ Johnson <johnsoncj@google.com>: Adds internal macros for catching and throwing unknown exception types PiperOrigin-RevId: 219207362 -- 0a9840328d2d86e8420b853435fdbf1f7a19d931 by Abseil Team <absl-team@google.com>: Fix typo in mutex.h comments. PiperOrigin-RevId: 219199397 -- 0d576dc7597564210bfdf91518075064756f0bf4 by Matt Calabrese <calabrese@google.com>: Internal change. PiperOrigin-RevId: 219185475 -- 66be156095571959fb19a76da8ad0b53ec37658e by Abseil Team <absl-team@google.com>: Fix alignment conformance for VS 2017 >= 15.8 (fix #193) PiperOrigin-RevId: 219129894 -- a6e1825a12587945f8194677ccfdcaba6f7aad1d by Abseil Team <absl-team@google.com>: Reapply PR #173 PiperOrigin-RevId: 219129361 -- cf72ade4881b25acc6ccaea468f69793a0fdce32 by Abseil Team <absl-team@google.com>: Update .gitignore PiperOrigin-RevId: 219127495 -- 0537490c6348a2cb489abe15638928ac5aa6982a by Jon Cohen <cohenjon@google.com>: Small refactor and reformat of error messages from the exception safety test framework. PiperOrigin-RevId: 218927773 -- 4c556ca45fa25698ad12002a00c713aeceefab73 by CJ Johnson <johnsoncj@google.com>: Updates the inlined vector swap tests to check for number of moves that took place if available PiperOrigin-RevId: 218900777 -- dcbfda0021a1e6dfa9586986b1269c06ec394053 by Mark Barolak <mbar@google.com>: Add parens around calls to std::numeric_limits<>::min and std::numeric_limits<>::max to prevent compilation errors on Windows platforms where min and max are defined as macros. PiperOrigin-RevId: 218888700 GitOrigin-RevId: ba4dd47492748bd630462eb68b7959037fc6a11a Change-Id: I0e393958eb8cb501b85f6114979f6d4d86ed996c
2018-10-29 23:53:34 +01:00
size_t max_size() const { return (std::numeric_limits<size_t>::max)(); }
void clear() {
// Iterating over this container is O(bucket_count()). When bucket_count()
// is much greater than size(), iteration becomes prohibitively expensive.
// For clear() it is more important to reuse the allocated array when the
// container is small because allocation takes comparatively long time
// compared to destruction of the elements of the container. So we pick the
// largest bucket_count() threshold for which iteration is still fast and
// past that we simply deallocate the array.
if (capacity_ > 127) {
destroy_slots();
} else if (capacity_) {
for (size_t i = 0; i != capacity_; ++i) {
if (IsFull(ctrl_[i])) {
PolicyTraits::destroy(&alloc_ref(), slots_ + i);
}
}
size_ = 0;
reset_ctrl();
growth_left() = static_cast<size_t>(capacity_ * kMaxLoadFactor);
}
assert(empty());
}
// This overload kicks in when the argument is an rvalue of insertable and
// decomposable type other than init_type.
//
// flat_hash_map<std::string, int> m;
// m.insert(std::make_pair("abc", 42));
template <class T, RequiresInsertable<T> = 0,
typename std::enable_if<IsDecomposable<T>::value, int>::type = 0,
T* = nullptr>
std::pair<iterator, bool> insert(T&& value) {
return emplace(std::forward<T>(value));
}
// This overload kicks in when the argument is a bitfield or an lvalue of
// insertable and decomposable type.
//
// union { int n : 1; };
// flat_hash_set<int> s;
// s.insert(n);
//
// flat_hash_set<std::string> s;
// const char* p = "hello";
// s.insert(p);
//
// TODO(romanp): Once we stop supporting gcc 5.1 and below, replace
// RequiresInsertable<T> with RequiresInsertable<const T&>.
// We are hitting this bug: https://godbolt.org/g/1Vht4f.
template <
class T, RequiresInsertable<T> = 0,
typename std::enable_if<IsDecomposable<const T&>::value, int>::type = 0>
std::pair<iterator, bool> insert(const T& value) {
return emplace(value);
}
// This overload kicks in when the argument is an rvalue of init_type. Its
// purpose is to handle brace-init-list arguments.
//
// flat_hash_set<std::string, int> s;
// s.insert({"abc", 42});
std::pair<iterator, bool> insert(init_type&& value) {
return emplace(std::move(value));
}
template <class T, RequiresInsertable<T> = 0,
typename std::enable_if<IsDecomposable<T>::value, int>::type = 0,
T* = nullptr>
iterator insert(const_iterator, T&& value) {
return insert(std::forward<T>(value)).first;
}
// TODO(romanp): Once we stop supporting gcc 5.1 and below, replace
// RequiresInsertable<T> with RequiresInsertable<const T&>.
// We are hitting this bug: https://godbolt.org/g/1Vht4f.
template <
class T, RequiresInsertable<T> = 0,
typename std::enable_if<IsDecomposable<const T&>::value, int>::type = 0>
iterator insert(const_iterator, const T& value) {
return insert(value).first;
}
iterator insert(const_iterator, init_type&& value) {
return insert(std::move(value)).first;
}
template <class InputIt>
void insert(InputIt first, InputIt last) {
for (; first != last; ++first) insert(*first);
}
template <class T, RequiresNotInit<T> = 0, RequiresInsertable<const T&> = 0>
void insert(std::initializer_list<T> ilist) {
insert(ilist.begin(), ilist.end());
}
void insert(std::initializer_list<init_type> ilist) {
insert(ilist.begin(), ilist.end());
}
insert_return_type<iterator, node_type> insert(node_type&& node) {
if (!node) return {end(), false, node_type()};
const auto& elem = PolicyTraits::element(node.slot());
auto res = PolicyTraits::apply(
InsertSlot<false>{*this, std::move(*node.slot())}, elem);
if (res.second) {
node.reset();
return {res.first, true, node_type()};
} else {
return {res.first, false, std::move(node)};
}
}
iterator insert(const_iterator, node_type&& node) {
return insert(std::move(node)).first;
}
// This overload kicks in if we can deduce the key from args. This enables us
// to avoid constructing value_type if an entry with the same key already
// exists.
//
// For example:
//
// flat_hash_map<std::string, std::string> m = {{"abc", "def"}};
// // Creates no std::string copies and makes no heap allocations.
// m.emplace("abc", "xyz");
template <class... Args, typename std::enable_if<
IsDecomposable<Args...>::value, int>::type = 0>
std::pair<iterator, bool> emplace(Args&&... args) {
return PolicyTraits::apply(EmplaceDecomposable{*this},
std::forward<Args>(args)...);
}
// This overload kicks in if we cannot deduce the key from args. It constructs
// value_type unconditionally and then either moves it into the table or
// destroys.
template <class... Args, typename std::enable_if<
!IsDecomposable<Args...>::value, int>::type = 0>
std::pair<iterator, bool> emplace(Args&&... args) {
typename std::aligned_storage<sizeof(slot_type), alignof(slot_type)>::type
raw;
slot_type* slot = reinterpret_cast<slot_type*>(&raw);
PolicyTraits::construct(&alloc_ref(), slot, std::forward<Args>(args)...);
const auto& elem = PolicyTraits::element(slot);
return PolicyTraits::apply(InsertSlot<true>{*this, std::move(*slot)}, elem);
}
template <class... Args>
iterator emplace_hint(const_iterator, Args&&... args) {
return emplace(std::forward<Args>(args)...).first;
}
// Extension API: support for lazy emplace.
//
// Looks up key in the table. If found, returns the iterator to the element.
// Otherwise calls f with one argument of type raw_hash_set::constructor. f
// MUST call raw_hash_set::constructor with arguments as if a
// raw_hash_set::value_type is constructed, otherwise the behavior is
// undefined.
//
// For example:
//
// std::unordered_set<ArenaString> s;
// // Makes ArenaStr even if "abc" is in the map.
// s.insert(ArenaString(&arena, "abc"));
//
// flat_hash_set<ArenaStr> s;
// // Makes ArenaStr only if "abc" is not in the map.
// s.lazy_emplace("abc", [&](const constructor& ctor) {
// ctor(&arena, "abc");
// });
//
// WARNING: This API is currently experimental. If there is a way to implement
// the same thing with the rest of the API, prefer that.
class constructor {
friend class raw_hash_set;
public:
template <class... Args>
void operator()(Args&&... args) const {
assert(*slot_);
PolicyTraits::construct(alloc_, *slot_, std::forward<Args>(args)...);
*slot_ = nullptr;
}
private:
constructor(allocator_type* a, slot_type** slot) : alloc_(a), slot_(slot) {}
allocator_type* alloc_;
slot_type** slot_;
};
template <class K = key_type, class F>
iterator lazy_emplace(const key_arg<K>& key, F&& f) {
auto res = find_or_prepare_insert(key);
if (res.second) {
slot_type* slot = slots_ + res.first;
std::forward<F>(f)(constructor(&alloc_ref(), &slot));
assert(!slot);
}
return iterator_at(res.first);
}
// Extension API: support for heterogeneous keys.
//
// std::unordered_set<std::string> s;
// // Turns "abc" into std::string.
// s.erase("abc");
//
// flat_hash_set<std::string> s;
// // Uses "abc" directly without copying it into std::string.
// s.erase("abc");
template <class K = key_type>
size_type erase(const key_arg<K>& key) {
auto it = find(key);
if (it == end()) return 0;
erase(it);
return 1;
}
// Erases the element pointed to by `it`. Unlike `std::unordered_set::erase`,
// this method returns void to reduce algorithmic complexity to O(1). In
// order to erase while iterating across a map, use the following idiom (which
// also works for standard containers):
//
// for (auto it = m.begin(), end = m.end(); it != end;) {
// if (<pred>) {
// m.erase(it++);
// } else {
// ++it;
// }
// }
void erase(const_iterator cit) { erase(cit.inner_); }
// This overload is necessary because otherwise erase<K>(const K&) would be
// a better match if non-const iterator is passed as an argument.
void erase(iterator it) {
assert(it != end());
PolicyTraits::destroy(&alloc_ref(), it.slot_);
erase_meta_only(it);
}
iterator erase(const_iterator first, const_iterator last) {
while (first != last) {
erase(first++);
}
return last.inner_;
}
// Moves elements from `src` into `this`.
// If the element already exists in `this`, it is left unmodified in `src`.
template <typename H, typename E>
void merge(raw_hash_set<Policy, H, E, Alloc>& src) { // NOLINT
assert(this != &src);
for (auto it = src.begin(), e = src.end(); it != e; ++it) {
if (PolicyTraits::apply(InsertSlot<false>{*this, std::move(*it.slot_)},
PolicyTraits::element(it.slot_))
.second) {
src.erase_meta_only(it);
}
}
}
template <typename H, typename E>
void merge(raw_hash_set<Policy, H, E, Alloc>&& src) {
merge(src);
}
node_type extract(const_iterator position) {
node_type node(alloc_ref(), position.inner_.slot_);
erase_meta_only(position);
return node;
}
template <
class K = key_type,
typename std::enable_if<!std::is_same<K, iterator>::value, int>::type = 0>
node_type extract(const key_arg<K>& key) {
auto it = find(key);
return it == end() ? node_type() : extract(const_iterator{it});
}
void swap(raw_hash_set& that) noexcept(
IsNoThrowSwappable<hasher>() && IsNoThrowSwappable<key_equal>() &&
(!AllocTraits::propagate_on_container_swap::value ||
IsNoThrowSwappable<allocator_type>())) {
using std::swap;
swap(ctrl_, that.ctrl_);
swap(slots_, that.slots_);
swap(size_, that.size_);
swap(capacity_, that.capacity_);
swap(growth_left(), that.growth_left());
swap(hash_ref(), that.hash_ref());
swap(eq_ref(), that.eq_ref());
if (AllocTraits::propagate_on_container_swap::value) {
swap(alloc_ref(), that.alloc_ref());
} else {
// If the allocators do not compare equal it is officially undefined
// behavior. We choose to do nothing.
}
}
void rehash(size_t n) {
if (n == 0 && capacity_ == 0) return;
if (n == 0 && size_ == 0) return destroy_slots();
Export of internal Abseil changes. -- 1c1d6e2404dfc6caa022b335df5acdac6da50fe1 by Derek Mauro <dmauro@google.com>: Fix the internal namespacing in unaligned_access.h PiperOrigin-RevId: 215434506 -- 17d4400aebf025a230690fc1c7a968ef8d85bbba by Eric Fiselier <ericwf@google.com>: gtest depends on the GCC extension allowing variadic macros to be passed a empty parameter pack for ..., but LLVM diagnoses this as a GNU extension. This patch suppresses the warning when building the absl tests. PiperOrigin-RevId: 215426161 -- f2c49dde23a9f445b9de963f1bbe840ebb568b30 by Eric Fiselier <ericwf@google.com>: Use EXPECT_DEATH_IF_SUPPORTED instead of EXPECT_DEATH. This avoids breaking the test when gtest doesn't support death tests. PiperOrigin-RevId: 215423849 -- cd687c1e121709603f4fc3726b534f6a9c52cc89 by Eric Fiselier <ericwf@google.com>: Disable LLVM's -Wmissing-variable-declarations in tests. GCC's configuration already disables this via -Wno-missing-declarations, this change makes LLVM do the same. The warning would otherwise flag most tests which use ABSL_FLAG. PiperOrigin-RevId: 215407429 -- d14098824c84e3a8c8f6fb920e0335fb48fe2010 by Eric Fiselier <ericwf@google.com>: Fix local variable shadowing in city hash implementation. PiperOrigin-RevId: 215407249 -- 4b5e140ba743f0d231790a26c49083abb4329e2c by Abseil Team <absl-team@google.com>: Make raw_hash_set::reserve 2X fast when reserve doesn't do any allocation. Make raw_hash_set::reserve ~1% faster when reserve does some (128~4k) allocation. PiperOrigin-RevId: 215348727 -- 461161e65e04b801480aa117af2534c594654ccf by Eric Fiselier <ericwf@google.com>: Internal change PiperOrigin-RevId: 215272283 -- 50413ae31ad3d3a177257416acd8ede47a17bff2 by Eric Fiselier <ericwf@google.com>: Internal Change PiperOrigin-RevId: 215233183 -- 477be54c43d61019a8fe4e190e340eb52737d383 by Abseil Team <absl-team@google.com>: Clarify misleading comment on ABSL_ATTRIBUTE_UNUSED PiperOrigin-RevId: 215185496 -- 2cafa2b5287507d3a946682aee9ab13af6d471c9 by Matt Kulukundis <kfm@google.com>: Add support for absl::Hash to various absl in types. PiperOrigin-RevId: 215039569 -- 082248901991aa3d29be0ea3689c7f213cf0fd83 by Derek Mauro <dmauro@google.com>: Remove an instance of HAS_GLOBAL_STRING from hash_function_defaults.h PiperOrigin-RevId: 214989094 -- b929f61907f0786a6133e3a9d7287e339c0a0acb by Derek Mauro <dmauro@google.com>: Internal import of Github #174 Fix code snippet in comment https://github.com/abseil/abseil-cpp/pull/174 PiperOrigin-RevId: 214958849 -- f2c5e829eca11c352e121f56eefbf87083305023 by Derek Mauro <dmauro@google.com>: Internal import of GitHub #173 Fix CMake build for absl::container. https://github.com/abseil/abseil-cpp/pull/173 PiperOrigin-RevId: 214957796 -- d704f860f9fddafb99e34e6c5032e49f73874e10 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 214828181 GitOrigin-RevId: 1c1d6e2404dfc6caa022b335df5acdac6da50fe1 Change-Id: I551de2b1ba0cbaf6856cd5959358cf6651179dea
2018-10-02 21:09:18 +02:00
auto m = NormalizeCapacity(std::max(n, NumSlotsFast(size())));
// n == 0 unconditionally rehashes as per the standard.
if (n == 0 || m > capacity_) {
resize(m);
}
}
void reserve(size_t n) {
Export of internal Abseil changes. -- 1c1d6e2404dfc6caa022b335df5acdac6da50fe1 by Derek Mauro <dmauro@google.com>: Fix the internal namespacing in unaligned_access.h PiperOrigin-RevId: 215434506 -- 17d4400aebf025a230690fc1c7a968ef8d85bbba by Eric Fiselier <ericwf@google.com>: gtest depends on the GCC extension allowing variadic macros to be passed a empty parameter pack for ..., but LLVM diagnoses this as a GNU extension. This patch suppresses the warning when building the absl tests. PiperOrigin-RevId: 215426161 -- f2c49dde23a9f445b9de963f1bbe840ebb568b30 by Eric Fiselier <ericwf@google.com>: Use EXPECT_DEATH_IF_SUPPORTED instead of EXPECT_DEATH. This avoids breaking the test when gtest doesn't support death tests. PiperOrigin-RevId: 215423849 -- cd687c1e121709603f4fc3726b534f6a9c52cc89 by Eric Fiselier <ericwf@google.com>: Disable LLVM's -Wmissing-variable-declarations in tests. GCC's configuration already disables this via -Wno-missing-declarations, this change makes LLVM do the same. The warning would otherwise flag most tests which use ABSL_FLAG. PiperOrigin-RevId: 215407429 -- d14098824c84e3a8c8f6fb920e0335fb48fe2010 by Eric Fiselier <ericwf@google.com>: Fix local variable shadowing in city hash implementation. PiperOrigin-RevId: 215407249 -- 4b5e140ba743f0d231790a26c49083abb4329e2c by Abseil Team <absl-team@google.com>: Make raw_hash_set::reserve 2X fast when reserve doesn't do any allocation. Make raw_hash_set::reserve ~1% faster when reserve does some (128~4k) allocation. PiperOrigin-RevId: 215348727 -- 461161e65e04b801480aa117af2534c594654ccf by Eric Fiselier <ericwf@google.com>: Internal change PiperOrigin-RevId: 215272283 -- 50413ae31ad3d3a177257416acd8ede47a17bff2 by Eric Fiselier <ericwf@google.com>: Internal Change PiperOrigin-RevId: 215233183 -- 477be54c43d61019a8fe4e190e340eb52737d383 by Abseil Team <absl-team@google.com>: Clarify misleading comment on ABSL_ATTRIBUTE_UNUSED PiperOrigin-RevId: 215185496 -- 2cafa2b5287507d3a946682aee9ab13af6d471c9 by Matt Kulukundis <kfm@google.com>: Add support for absl::Hash to various absl in types. PiperOrigin-RevId: 215039569 -- 082248901991aa3d29be0ea3689c7f213cf0fd83 by Derek Mauro <dmauro@google.com>: Remove an instance of HAS_GLOBAL_STRING from hash_function_defaults.h PiperOrigin-RevId: 214989094 -- b929f61907f0786a6133e3a9d7287e339c0a0acb by Derek Mauro <dmauro@google.com>: Internal import of Github #174 Fix code snippet in comment https://github.com/abseil/abseil-cpp/pull/174 PiperOrigin-RevId: 214958849 -- f2c5e829eca11c352e121f56eefbf87083305023 by Derek Mauro <dmauro@google.com>: Internal import of GitHub #173 Fix CMake build for absl::container. https://github.com/abseil/abseil-cpp/pull/173 PiperOrigin-RevId: 214957796 -- d704f860f9fddafb99e34e6c5032e49f73874e10 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 214828181 GitOrigin-RevId: 1c1d6e2404dfc6caa022b335df5acdac6da50fe1 Change-Id: I551de2b1ba0cbaf6856cd5959358cf6651179dea
2018-10-02 21:09:18 +02:00
rehash(NumSlotsFast(n));
}
// Extension API: support for heterogeneous keys.
//
// std::unordered_set<std::string> s;
// // Turns "abc" into std::string.
// s.count("abc");
//
// ch_set<std::string> s;
// // Uses "abc" directly without copying it into std::string.
// s.count("abc");
template <class K = key_type>
size_t count(const key_arg<K>& key) const {
return find(key) == end() ? 0 : 1;
}
// Issues CPU prefetch instructions for the memory needed to find or insert
// a key. Like all lookup functions, this support heterogeneous keys.
//
// NOTE: This is a very low level operation and should not be used without
// specific benchmarks indicating its importance.
template <class K = key_type>
void prefetch(const key_arg<K>& key) const {
(void)key;
#if defined(__GNUC__)
auto seq = probe(hash_ref()(key));
__builtin_prefetch(static_cast<const void*>(ctrl_ + seq.offset()));
__builtin_prefetch(static_cast<const void*>(slots_ + seq.offset()));
#endif // __GNUC__
}
// The API of find() has two extensions.
//
// 1. The hash can be passed by the user. It must be equal to the hash of the
// key.
//
// 2. The type of the key argument doesn't have to be key_type. This is so
// called heterogeneous key support.
template <class K = key_type>
iterator find(const key_arg<K>& key, size_t hash) {
auto seq = probe(hash);
while (true) {
Group g{ctrl_ + seq.offset()};
for (int i : g.Match(H2(hash))) {
if (ABSL_PREDICT_TRUE(PolicyTraits::apply(
EqualElement<K>{key, eq_ref()},
PolicyTraits::element(slots_ + seq.offset(i)))))
return iterator_at(seq.offset(i));
}
if (ABSL_PREDICT_TRUE(g.MatchEmpty())) return end();
seq.next();
}
}
template <class K = key_type>
iterator find(const key_arg<K>& key) {
return find(key, hash_ref()(key));
}
template <class K = key_type>
const_iterator find(const key_arg<K>& key, size_t hash) const {
return const_cast<raw_hash_set*>(this)->find(key, hash);
}
template <class K = key_type>
const_iterator find(const key_arg<K>& key) const {
return find(key, hash_ref()(key));
}
template <class K = key_type>
bool contains(const key_arg<K>& key) const {
return find(key) != end();
}
template <class K = key_type>
std::pair<iterator, iterator> equal_range(const key_arg<K>& key) {
auto it = find(key);
if (it != end()) return {it, std::next(it)};
return {it, it};
}
template <class K = key_type>
std::pair<const_iterator, const_iterator> equal_range(
const key_arg<K>& key) const {
auto it = find(key);
if (it != end()) return {it, std::next(it)};
return {it, it};
}
size_t bucket_count() const { return capacity_; }
float load_factor() const {
return capacity_ ? static_cast<double>(size()) / capacity_ : 0.0;
}
float max_load_factor() const { return 1.0f; }
void max_load_factor(float) {
// Does nothing.
}
hasher hash_function() const { return hash_ref(); }
key_equal key_eq() const { return eq_ref(); }
allocator_type get_allocator() const { return alloc_ref(); }
friend bool operator==(const raw_hash_set& a, const raw_hash_set& b) {
if (a.size() != b.size()) return false;
const raw_hash_set* outer = &a;
const raw_hash_set* inner = &b;
if (outer->capacity() > inner->capacity()) std::swap(outer, inner);
for (const value_type& elem : *outer)
if (!inner->has_element(elem)) return false;
return true;
}
friend bool operator!=(const raw_hash_set& a, const raw_hash_set& b) {
return !(a == b);
}
friend void swap(raw_hash_set& a,
raw_hash_set& b) noexcept(noexcept(a.swap(b))) {
a.swap(b);
}
private:
template <class Container, typename Enabler>
friend struct absl::container_internal::hashtable_debug_internal::
HashtableDebugAccess;
struct FindElement {
template <class K, class... Args>
const_iterator operator()(const K& key, Args&&...) const {
return s.find(key);
}
const raw_hash_set& s;
};
struct HashElement {
template <class K, class... Args>
size_t operator()(const K& key, Args&&...) const {
return h(key);
}
const hasher& h;
};
template <class K1>
struct EqualElement {
template <class K2, class... Args>
bool operator()(const K2& lhs, Args&&...) const {
return eq(lhs, rhs);
}
const K1& rhs;
const key_equal& eq;
};
struct EmplaceDecomposable {
template <class K, class... Args>
std::pair<iterator, bool> operator()(const K& key, Args&&... args) const {
auto res = s.find_or_prepare_insert(key);
if (res.second) {
s.emplace_at(res.first, std::forward<Args>(args)...);
}
return {s.iterator_at(res.first), res.second};
}
raw_hash_set& s;
};
template <bool do_destroy>
struct InsertSlot {
template <class K, class... Args>
std::pair<iterator, bool> operator()(const K& key, Args&&...) && {
auto res = s.find_or_prepare_insert(key);
if (res.second) {
PolicyTraits::transfer(&s.alloc_ref(), s.slots_ + res.first, &slot);
} else if (do_destroy) {
PolicyTraits::destroy(&s.alloc_ref(), &slot);
}
return {s.iterator_at(res.first), res.second};
}
raw_hash_set& s;
// Constructed slot. Either moved into place or destroyed.
slot_type&& slot;
};
Export of internal Abseil changes. -- 1c1d6e2404dfc6caa022b335df5acdac6da50fe1 by Derek Mauro <dmauro@google.com>: Fix the internal namespacing in unaligned_access.h PiperOrigin-RevId: 215434506 -- 17d4400aebf025a230690fc1c7a968ef8d85bbba by Eric Fiselier <ericwf@google.com>: gtest depends on the GCC extension allowing variadic macros to be passed a empty parameter pack for ..., but LLVM diagnoses this as a GNU extension. This patch suppresses the warning when building the absl tests. PiperOrigin-RevId: 215426161 -- f2c49dde23a9f445b9de963f1bbe840ebb568b30 by Eric Fiselier <ericwf@google.com>: Use EXPECT_DEATH_IF_SUPPORTED instead of EXPECT_DEATH. This avoids breaking the test when gtest doesn't support death tests. PiperOrigin-RevId: 215423849 -- cd687c1e121709603f4fc3726b534f6a9c52cc89 by Eric Fiselier <ericwf@google.com>: Disable LLVM's -Wmissing-variable-declarations in tests. GCC's configuration already disables this via -Wno-missing-declarations, this change makes LLVM do the same. The warning would otherwise flag most tests which use ABSL_FLAG. PiperOrigin-RevId: 215407429 -- d14098824c84e3a8c8f6fb920e0335fb48fe2010 by Eric Fiselier <ericwf@google.com>: Fix local variable shadowing in city hash implementation. PiperOrigin-RevId: 215407249 -- 4b5e140ba743f0d231790a26c49083abb4329e2c by Abseil Team <absl-team@google.com>: Make raw_hash_set::reserve 2X fast when reserve doesn't do any allocation. Make raw_hash_set::reserve ~1% faster when reserve does some (128~4k) allocation. PiperOrigin-RevId: 215348727 -- 461161e65e04b801480aa117af2534c594654ccf by Eric Fiselier <ericwf@google.com>: Internal change PiperOrigin-RevId: 215272283 -- 50413ae31ad3d3a177257416acd8ede47a17bff2 by Eric Fiselier <ericwf@google.com>: Internal Change PiperOrigin-RevId: 215233183 -- 477be54c43d61019a8fe4e190e340eb52737d383 by Abseil Team <absl-team@google.com>: Clarify misleading comment on ABSL_ATTRIBUTE_UNUSED PiperOrigin-RevId: 215185496 -- 2cafa2b5287507d3a946682aee9ab13af6d471c9 by Matt Kulukundis <kfm@google.com>: Add support for absl::Hash to various absl in types. PiperOrigin-RevId: 215039569 -- 082248901991aa3d29be0ea3689c7f213cf0fd83 by Derek Mauro <dmauro@google.com>: Remove an instance of HAS_GLOBAL_STRING from hash_function_defaults.h PiperOrigin-RevId: 214989094 -- b929f61907f0786a6133e3a9d7287e339c0a0acb by Derek Mauro <dmauro@google.com>: Internal import of Github #174 Fix code snippet in comment https://github.com/abseil/abseil-cpp/pull/174 PiperOrigin-RevId: 214958849 -- f2c5e829eca11c352e121f56eefbf87083305023 by Derek Mauro <dmauro@google.com>: Internal import of GitHub #173 Fix CMake build for absl::container. https://github.com/abseil/abseil-cpp/pull/173 PiperOrigin-RevId: 214957796 -- d704f860f9fddafb99e34e6c5032e49f73874e10 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 214828181 GitOrigin-RevId: 1c1d6e2404dfc6caa022b335df5acdac6da50fe1 Change-Id: I551de2b1ba0cbaf6856cd5959358cf6651179dea
2018-10-02 21:09:18 +02:00
// Computes std::ceil(n / kMaxLoadFactor). Faster than calling std::ceil.
static inline size_t NumSlotsFast(size_t n) {
return static_cast<size_t>(
(n * kMaxLoadFactorDenominator + (kMaxLoadFactorNumerator - 1)) /
kMaxLoadFactorNumerator);
}
// "erases" the object from the container, except that it doesn't actually
// destroy the object. It only updates all the metadata of the class.
// This can be used in conjunction with Policy::transfer to move the object to
// another place.
void erase_meta_only(const_iterator it) {
assert(IsFull(*it.inner_.ctrl_) && "erasing a dangling iterator");
--size_;
const size_t index = it.inner_.ctrl_ - ctrl_;
const size_t index_before = (index - Group::kWidth) & capacity_;
const auto empty_after = Group(it.inner_.ctrl_).MatchEmpty();
const auto empty_before = Group(ctrl_ + index_before).MatchEmpty();
// We count how many consecutive non empties we have to the right and to the
// left of `it`. If the sum is >= kWidth then there is at least one probe
// window that might have seen a full group.
bool was_never_full =
empty_before && empty_after &&
static_cast<size_t>(empty_after.TrailingZeros() +
empty_before.LeadingZeros()) < Group::kWidth;
set_ctrl(index, was_never_full ? kEmpty : kDeleted);
growth_left() += was_never_full;
}
void initialize_slots() {
assert(capacity_);
auto layout = MakeLayout(capacity_);
char* mem = static_cast<char*>(
Allocate<Layout::Alignment()>(&alloc_ref(), layout.AllocSize()));
ctrl_ = reinterpret_cast<ctrl_t*>(layout.template Pointer<0>(mem));
slots_ = layout.template Pointer<1>(mem);
reset_ctrl();
growth_left() = static_cast<size_t>(capacity_ * kMaxLoadFactor) - size_;
}
void destroy_slots() {
if (!capacity_) return;
for (size_t i = 0; i != capacity_; ++i) {
if (IsFull(ctrl_[i])) {
PolicyTraits::destroy(&alloc_ref(), slots_ + i);
}
}
auto layout = MakeLayout(capacity_);
// Unpoison before returning the memory to the allocator.
SanitizerUnpoisonMemoryRegion(slots_, sizeof(slot_type) * capacity_);
Deallocate<Layout::Alignment()>(&alloc_ref(), ctrl_, layout.AllocSize());
ctrl_ = EmptyGroup();
slots_ = nullptr;
size_ = 0;
capacity_ = 0;
growth_left() = 0;
}
void resize(size_t new_capacity) {
assert(IsValidCapacity(new_capacity));
auto* old_ctrl = ctrl_;
auto* old_slots = slots_;
const size_t old_capacity = capacity_;
capacity_ = new_capacity;
initialize_slots();
for (size_t i = 0; i != old_capacity; ++i) {
if (IsFull(old_ctrl[i])) {
size_t hash = PolicyTraits::apply(HashElement{hash_ref()},
PolicyTraits::element(old_slots + i));
size_t new_i = find_first_non_full(hash);
set_ctrl(new_i, H2(hash));
PolicyTraits::transfer(&alloc_ref(), slots_ + new_i, old_slots + i);
}
}
if (old_capacity) {
SanitizerUnpoisonMemoryRegion(old_slots,
sizeof(slot_type) * old_capacity);
auto layout = MakeLayout(old_capacity);
Deallocate<Layout::Alignment()>(&alloc_ref(), old_ctrl,
layout.AllocSize());
}
}
void drop_deletes_without_resize() ABSL_ATTRIBUTE_NOINLINE {
assert(IsValidCapacity(capacity_));
// Algorithm:
// - mark all DELETED slots as EMPTY
// - mark all FULL slots as DELETED
// - for each slot marked as DELETED
// hash = Hash(element)
// target = find_first_non_full(hash)
// if target is in the same group
// mark slot as FULL
// else if target is EMPTY
// transfer element to target
// mark slot as EMPTY
// mark target as FULL
// else if target is DELETED
// swap current element with target element
// mark target as FULL
// repeat procedure for current slot with moved from element (target)
ConvertDeletedToEmptyAndFullToDeleted(ctrl_, capacity_);
typename std::aligned_storage<sizeof(slot_type), alignof(slot_type)>::type
raw;
slot_type* slot = reinterpret_cast<slot_type*>(&raw);
for (size_t i = 0; i != capacity_; ++i) {
if (!IsDeleted(ctrl_[i])) continue;
size_t hash = PolicyTraits::apply(HashElement{hash_ref()},
PolicyTraits::element(slots_ + i));
size_t new_i = find_first_non_full(hash);
// Verify if the old and new i fall within the same group wrt the hash.
// If they do, we don't need to move the object as it falls already in the
// best probe we can.
const auto probe_index = [&](size_t pos) {
return ((pos - probe(hash).offset()) & capacity_) / Group::kWidth;
};
// Element doesn't move.
if (ABSL_PREDICT_TRUE(probe_index(new_i) == probe_index(i))) {
set_ctrl(i, H2(hash));
continue;
}
if (IsEmpty(ctrl_[new_i])) {
// Transfer element to the empty spot.
// set_ctrl poisons/unpoisons the slots so we have to call it at the
// right time.
set_ctrl(new_i, H2(hash));
PolicyTraits::transfer(&alloc_ref(), slots_ + new_i, slots_ + i);
set_ctrl(i, kEmpty);
} else {
assert(IsDeleted(ctrl_[new_i]));
set_ctrl(new_i, H2(hash));
// Until we are done rehashing, DELETED marks previously FULL slots.
// Swap i and new_i elements.
PolicyTraits::transfer(&alloc_ref(), slot, slots_ + i);
PolicyTraits::transfer(&alloc_ref(), slots_ + i, slots_ + new_i);
PolicyTraits::transfer(&alloc_ref(), slots_ + new_i, slot);
--i; // repeat
}
}
growth_left() = static_cast<size_t>(capacity_ * kMaxLoadFactor) - size_;
}
void rehash_and_grow_if_necessary() {
if (capacity_ == 0) {
resize(Group::kWidth - 1);
} else if (size() <= kMaxLoadFactor / 2 * capacity_) {
// Squash DELETED without growing if there is enough capacity.
drop_deletes_without_resize();
} else {
// Otherwise grow the container.
resize(capacity_ * 2 + 1);
}
}
bool has_element(const value_type& elem) const {
size_t hash = PolicyTraits::apply(HashElement{hash_ref()}, elem);
auto seq = probe(hash);
while (true) {
Group g{ctrl_ + seq.offset()};
for (int i : g.Match(H2(hash))) {
if (ABSL_PREDICT_TRUE(PolicyTraits::element(slots_ + seq.offset(i)) ==
elem))
return true;
}
if (ABSL_PREDICT_TRUE(g.MatchEmpty())) return false;
seq.next();
assert(seq.index() < capacity_ && "full table!");
}
return false;
}
// Probes the raw_hash_set with the probe sequence for hash and returns the
// pointer to the first empty or deleted slot.
// NOTE: this function must work with tables having both kEmpty and kDelete
// in one group. Such tables appears during drop_deletes_without_resize.
//
// This function is very useful when insertions happen and:
// - the input is already a set
// - there are enough slots
// - the element with the hash is not in the table
size_t find_first_non_full(size_t hash) {
auto seq = probe(hash);
while (true) {
Group g{ctrl_ + seq.offset()};
auto mask = g.MatchEmptyOrDeleted();
if (mask) {
#if !defined(NDEBUG)
// We want to force small tables to have random entries too, so
// in debug build we will randomly insert in either the front or back of
// the group.
// TODO(kfm,sbenza): revisit after we do unconditional mixing
if (ShouldInsertBackwards(hash, ctrl_))
return seq.offset(mask.HighestBitSet());
else
return seq.offset(mask.LowestBitSet());
#else
return seq.offset(mask.LowestBitSet());
#endif
}
assert(seq.index() < capacity_ && "full table!");
seq.next();
}
}
// TODO(alkis): Optimize this assuming *this and that don't overlap.
raw_hash_set& move_assign(raw_hash_set&& that, std::true_type) {
raw_hash_set tmp(std::move(that));
swap(tmp);
return *this;
}
raw_hash_set& move_assign(raw_hash_set&& that, std::false_type) {
raw_hash_set tmp(std::move(that), alloc_ref());
swap(tmp);
return *this;
}
protected:
template <class K>
std::pair<size_t, bool> find_or_prepare_insert(const K& key) {
auto hash = hash_ref()(key);
auto seq = probe(hash);
while (true) {
Group g{ctrl_ + seq.offset()};
for (int i : g.Match(H2(hash))) {
if (ABSL_PREDICT_TRUE(PolicyTraits::apply(
EqualElement<K>{key, eq_ref()},
PolicyTraits::element(slots_ + seq.offset(i)))))
return {seq.offset(i), false};
}
if (ABSL_PREDICT_TRUE(g.MatchEmpty())) break;
seq.next();
}
return {prepare_insert(hash), true};
}
size_t prepare_insert(size_t hash) ABSL_ATTRIBUTE_NOINLINE {
size_t target = find_first_non_full(hash);
if (ABSL_PREDICT_FALSE(growth_left() == 0 && !IsDeleted(ctrl_[target]))) {
rehash_and_grow_if_necessary();
target = find_first_non_full(hash);
}
++size_;
growth_left() -= IsEmpty(ctrl_[target]);
set_ctrl(target, H2(hash));
return target;
}
// Constructs the value in the space pointed by the iterator. This only works
// after an unsuccessful find_or_prepare_insert() and before any other
// modifications happen in the raw_hash_set.
//
// PRECONDITION: i is an index returned from find_or_prepare_insert(k), where
// k is the key decomposed from `forward<Args>(args)...`, and the bool
// returned by find_or_prepare_insert(k) was true.
// POSTCONDITION: *m.iterator_at(i) == value_type(forward<Args>(args)...).
template <class... Args>
void emplace_at(size_t i, Args&&... args) {
PolicyTraits::construct(&alloc_ref(), slots_ + i,
std::forward<Args>(args)...);
assert(PolicyTraits::apply(FindElement{*this}, *iterator_at(i)) ==
iterator_at(i) &&
"constructed value does not match the lookup key");
}
iterator iterator_at(size_t i) { return {ctrl_ + i, slots_ + i}; }
const_iterator iterator_at(size_t i) const { return {ctrl_ + i, slots_ + i}; }
private:
friend struct RawHashSetTestOnlyAccess;
probe_seq<Group::kWidth> probe(size_t hash) const {
return probe_seq<Group::kWidth>(H1(hash, ctrl_), capacity_);
}
// Reset all ctrl bytes back to kEmpty, except the sentinel.
void reset_ctrl() {
std::memset(ctrl_, kEmpty, capacity_ + Group::kWidth);
ctrl_[capacity_] = kSentinel;
SanitizerPoisonMemoryRegion(slots_, sizeof(slot_type) * capacity_);
}
// Sets the control byte, and if `i < Group::kWidth`, set the cloned byte at
// the end too.
void set_ctrl(size_t i, ctrl_t h) {
assert(i < capacity_);
if (IsFull(h)) {
SanitizerUnpoisonObject(slots_ + i);
} else {
SanitizerPoisonObject(slots_ + i);
}
ctrl_[i] = h;
ctrl_[((i - Group::kWidth) & capacity_) + Group::kWidth] = h;
}
size_t& growth_left() { return settings_.template get<0>(); }
hasher& hash_ref() { return settings_.template get<1>(); }
const hasher& hash_ref() const { return settings_.template get<1>(); }
key_equal& eq_ref() { return settings_.template get<2>(); }
const key_equal& eq_ref() const { return settings_.template get<2>(); }
allocator_type& alloc_ref() { return settings_.template get<3>(); }
const allocator_type& alloc_ref() const {
return settings_.template get<3>();
}
// On average each group has 2 empty slot (for the vectorized case).
Export of internal Abseil changes. -- 1c1d6e2404dfc6caa022b335df5acdac6da50fe1 by Derek Mauro <dmauro@google.com>: Fix the internal namespacing in unaligned_access.h PiperOrigin-RevId: 215434506 -- 17d4400aebf025a230690fc1c7a968ef8d85bbba by Eric Fiselier <ericwf@google.com>: gtest depends on the GCC extension allowing variadic macros to be passed a empty parameter pack for ..., but LLVM diagnoses this as a GNU extension. This patch suppresses the warning when building the absl tests. PiperOrigin-RevId: 215426161 -- f2c49dde23a9f445b9de963f1bbe840ebb568b30 by Eric Fiselier <ericwf@google.com>: Use EXPECT_DEATH_IF_SUPPORTED instead of EXPECT_DEATH. This avoids breaking the test when gtest doesn't support death tests. PiperOrigin-RevId: 215423849 -- cd687c1e121709603f4fc3726b534f6a9c52cc89 by Eric Fiselier <ericwf@google.com>: Disable LLVM's -Wmissing-variable-declarations in tests. GCC's configuration already disables this via -Wno-missing-declarations, this change makes LLVM do the same. The warning would otherwise flag most tests which use ABSL_FLAG. PiperOrigin-RevId: 215407429 -- d14098824c84e3a8c8f6fb920e0335fb48fe2010 by Eric Fiselier <ericwf@google.com>: Fix local variable shadowing in city hash implementation. PiperOrigin-RevId: 215407249 -- 4b5e140ba743f0d231790a26c49083abb4329e2c by Abseil Team <absl-team@google.com>: Make raw_hash_set::reserve 2X fast when reserve doesn't do any allocation. Make raw_hash_set::reserve ~1% faster when reserve does some (128~4k) allocation. PiperOrigin-RevId: 215348727 -- 461161e65e04b801480aa117af2534c594654ccf by Eric Fiselier <ericwf@google.com>: Internal change PiperOrigin-RevId: 215272283 -- 50413ae31ad3d3a177257416acd8ede47a17bff2 by Eric Fiselier <ericwf@google.com>: Internal Change PiperOrigin-RevId: 215233183 -- 477be54c43d61019a8fe4e190e340eb52737d383 by Abseil Team <absl-team@google.com>: Clarify misleading comment on ABSL_ATTRIBUTE_UNUSED PiperOrigin-RevId: 215185496 -- 2cafa2b5287507d3a946682aee9ab13af6d471c9 by Matt Kulukundis <kfm@google.com>: Add support for absl::Hash to various absl in types. PiperOrigin-RevId: 215039569 -- 082248901991aa3d29be0ea3689c7f213cf0fd83 by Derek Mauro <dmauro@google.com>: Remove an instance of HAS_GLOBAL_STRING from hash_function_defaults.h PiperOrigin-RevId: 214989094 -- b929f61907f0786a6133e3a9d7287e339c0a0acb by Derek Mauro <dmauro@google.com>: Internal import of Github #174 Fix code snippet in comment https://github.com/abseil/abseil-cpp/pull/174 PiperOrigin-RevId: 214958849 -- f2c5e829eca11c352e121f56eefbf87083305023 by Derek Mauro <dmauro@google.com>: Internal import of GitHub #173 Fix CMake build for absl::container. https://github.com/abseil/abseil-cpp/pull/173 PiperOrigin-RevId: 214957796 -- d704f860f9fddafb99e34e6c5032e49f73874e10 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 214828181 GitOrigin-RevId: 1c1d6e2404dfc6caa022b335df5acdac6da50fe1 Change-Id: I551de2b1ba0cbaf6856cd5959358cf6651179dea
2018-10-02 21:09:18 +02:00
static constexpr int64_t kMaxLoadFactorNumerator = 14;
static constexpr int64_t kMaxLoadFactorDenominator = 16;
static constexpr float kMaxLoadFactor =
1.0 * kMaxLoadFactorNumerator / kMaxLoadFactorDenominator;
// TODO(alkis): Investigate removing some of these fields:
// - ctrl/slots can be derived from each other
// - size can be moved into the slot array
ctrl_t* ctrl_ = EmptyGroup(); // [(capacity + 1) * ctrl_t]
slot_type* slots_ = nullptr; // [capacity * slot_type]
size_t size_ = 0; // number of full slots
size_t capacity_ = 0; // total number of slots
absl::container_internal::CompressedTuple<size_t /* growth_left */, hasher,
key_equal, allocator_type>
settings_{0, hasher{}, key_equal{}, allocator_type{}};
};
namespace hashtable_debug_internal {
template <typename Set>
struct HashtableDebugAccess<Set, absl::void_t<typename Set::raw_hash_set>> {
using Traits = typename Set::PolicyTraits;
using Slot = typename Traits::slot_type;
static size_t GetNumProbes(const Set& set,
const typename Set::key_type& key) {
size_t num_probes = 0;
size_t hash = set.hash_ref()(key);
auto seq = set.probe(hash);
while (true) {
container_internal::Group g{set.ctrl_ + seq.offset()};
for (int i : g.Match(container_internal::H2(hash))) {
if (Traits::apply(
typename Set::template EqualElement<typename Set::key_type>{
key, set.eq_ref()},
Traits::element(set.slots_ + seq.offset(i))))
return num_probes;
++num_probes;
}
if (g.MatchEmpty()) return num_probes;
seq.next();
++num_probes;
}
}
static size_t AllocatedByteSize(const Set& c) {
size_t capacity = c.capacity_;
if (capacity == 0) return 0;
auto layout = Set::MakeLayout(capacity);
size_t m = layout.AllocSize();
size_t per_slot = Traits::space_used(static_cast<const Slot*>(nullptr));
if (per_slot != ~size_t{}) {
m += per_slot * c.size();
} else {
for (size_t i = 0; i != capacity; ++i) {
if (container_internal::IsFull(c.ctrl_[i])) {
m += Traits::space_used(c.slots_ + i);
}
}
}
return m;
}
static size_t LowerBoundAllocatedByteSize(size_t size) {
size_t capacity = container_internal::NormalizeCapacity(
std::ceil(size / Set::kMaxLoadFactor));
if (capacity == 0) return 0;
auto layout = Set::MakeLayout(capacity);
size_t m = layout.AllocSize();
size_t per_slot = Traits::space_used(static_cast<const Slot*>(nullptr));
if (per_slot != ~size_t{}) {
m += per_slot * size;
}
return m;
}
};
} // namespace hashtable_debug_internal
} // namespace container_internal
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_RAW_HASH_SET_H_