tvl-depot/absl/random/internal/nonsecure_base.h

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Export of internal Abseil changes. -- 7a6ff16a85beb730c172d5d25cf1b5e1be885c56 by Laramie Leavitt <lar@google.com>: Internal change. PiperOrigin-RevId: 254454546 -- ff8f9bafaefc26d451f576ea4a06d150aed63f6f by Andy Soffer <asoffer@google.com>: Internal changes PiperOrigin-RevId: 254451562 -- deefc5b651b479ce36f0b4ef203e119c0c8936f2 by CJ Johnson <johnsoncj@google.com>: Account for subtracting unsigned values from the size of InlinedVector PiperOrigin-RevId: 254450625 -- 3c677316a27bcadc17e41957c809ca472d5fef14 by Andy Soffer <asoffer@google.com>: Add C++17's std::make_from_tuple to absl/utility/utility.h PiperOrigin-RevId: 254411573 -- 4ee3536a918830eeec402a28fc31a62c7c90b940 by CJ Johnson <johnsoncj@google.com>: Adds benchmark for the rest of the InlinedVector public API PiperOrigin-RevId: 254408378 -- e5a21a00700ee83498ff1efbf649169756463ee4 by CJ Johnson <johnsoncj@google.com>: Updates the definition of InlinedVector::shrink_to_fit() to be exception safe and adds exception safety tests for it. PiperOrigin-RevId: 254401387 -- 2ea82e72b86d82d78b4e4712a63a55981b53c64b by Laramie Leavitt <lar@google.com>: Use absl::InsecureBitGen in place of std::mt19937 in tests absl/random/...distribution_test.cc PiperOrigin-RevId: 254289444 -- fa099e02c413a7ffda732415e8105cad26a90337 by Andy Soffer <asoffer@google.com>: Internal changes PiperOrigin-RevId: 254286334 -- ce34b7f36933b30cfa35b9c9a5697a792b5666e4 by Andy Soffer <asoffer@google.com>: Internal changes PiperOrigin-RevId: 254273059 -- 6f9c473da7c2090c2e85a37c5f00622e8a912a89 by Jorg Brown <jorg@google.com>: Change absl::container_internal::CompressedTuple to instantiate its internal Storage class with the name of the type it's holding, rather than the name of the Tuple. This is not an externally-visible change, other than less compiler memory is used and less debug information is generated. PiperOrigin-RevId: 254269285 -- 8bd3c186bf2fc0c55d8a2dd6f28a5327502c9fba by Andy Soffer <asoffer@google.com>: Adding short-hand IntervalClosed for IntervalClosedClosed and IntervalOpen for IntervalOpenOpen. PiperOrigin-RevId: 254252419 -- ea957f99b6a04fccd42aa05605605f3b44b1ecfd by Abseil Team <absl-team@google.com>: Do not directly use __SIZEOF_INT128__. In order to avoid linker errors when building with clang-cl (__fixunsdfti, __udivti3 and __fixunssfti are undefined), this CL uses ABSL_HAVE_INTRINSIC_INT128 which is not defined for clang-cl. PiperOrigin-RevId: 254250739 -- 89ab385cd26b34d64130bce856253aaba96d2345 by Andy Soffer <asoffer@google.com>: Internal changes PiperOrigin-RevId: 254242321 -- cffc793d93eca6d6bdf7de733847b6ab4a255ae9 by CJ Johnson <johnsoncj@google.com>: Adds benchmark for InlinedVector::reserve(size_type) PiperOrigin-RevId: 254199226 -- c90c7a9fa3c8f0c9d5114036979548b055ea2f2a by Gennadiy Rozental <rogeeff@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 254072387 -- c4c388beae016c9570ab54ffa1d52660e4a85b7b by Laramie Leavitt <lar@google.com>: Internal cleanup. PiperOrigin-RevId: 254062381 -- d3c992e221cc74e5372d0c8fa410170b6a43c062 by Tom Manshreck <shreck@google.com>: Update distributions.h to Abseil standards PiperOrigin-RevId: 254054946 -- d15ad0035c34ef11b14fadc5a4a2d3ec415f5518 by CJ Johnson <johnsoncj@google.com>: Removes functions with only one caller from the implementation details of InlinedVector by manually inlining the definitions PiperOrigin-RevId: 254005427 -- 2f37e807efc3a8ef1f4b539bdd379917d4151520 by Andy Soffer <asoffer@google.com>: Initial release of Abseil Random PiperOrigin-RevId: 253999861 -- 24ed1694b6430791d781ed533a8f8ccf6cac5856 by CJ Johnson <johnsoncj@google.com>: Updates the definition of InlinedVector::assign(...)/InlinedVector::operator=(...) to new, exception-safe implementations with exception safety tests to boot PiperOrigin-RevId: 253993691 -- 5613d95f5a7e34a535cfaeadce801441e990843e by CJ Johnson <johnsoncj@google.com>: Adds benchmarks for InlinedVector::shrink_to_fit() PiperOrigin-RevId: 253989647 -- 2a96ddfdac40bbb8cb6a7f1aeab90917067c6e63 by Abseil Team <absl-team@google.com>: Initial release of Abseil Random PiperOrigin-RevId: 253927497 -- bf1aff8fc9ffa921ad74643e9525ecf25b0d8dc1 by Andy Soffer <asoffer@google.com>: Initial release of Abseil Random PiperOrigin-RevId: 253920512 -- bfc03f4a3dcda3cf3a4b84bdb84cda24e3394f41 by Laramie Leavitt <lar@google.com>: Internal change. PiperOrigin-RevId: 253886486 -- 05036cfcc078ca7c5f581a00dfb0daed568cbb69 by Eric Fiselier <ericwf@google.com>: Don't include `winsock2.h` because it drags in `windows.h` and friends, and they define awful macros like OPAQUE, ERROR, and more. This has the potential to break abseil users. Instead we only forward declare `timeval` and require Windows users include `winsock2.h` themselves. This is both inconsistent and poor QoI, but so including 'windows.h' is bad too. PiperOrigin-RevId: 253852615 GitOrigin-RevId: 7a6ff16a85beb730c172d5d25cf1b5e1be885c56 Change-Id: Icd6aff87da26f29ec8915da856f051129987cef6
2019-06-21 22:11:42 +02:00
// Copyright 2017 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef ABSL_RANDOM_INTERNAL_NONSECURE_BASE_H_
#define ABSL_RANDOM_INTERNAL_NONSECURE_BASE_H_
#include <algorithm>
#include <cstdint>
#include <iostream>
#include <iterator>
#include <random>
#include <string>
#include <type_traits>
#include <vector>
#include "absl/base/macros.h"
#include "absl/meta/type_traits.h"
#include "absl/random/internal/pool_urbg.h"
#include "absl/random/internal/salted_seed_seq.h"
#include "absl/random/internal/seed_material.h"
#include "absl/types/optional.h"
#include "absl/types/span.h"
namespace absl {
namespace random_internal {
// Each instance of NonsecureURBGBase<URBG> will be seeded by variates produced
// by a thread-unique URBG-instance.
template <typename URBG>
class NonsecureURBGBase {
public:
using result_type = typename URBG::result_type;
// Default constructor
NonsecureURBGBase() : urbg_(ConstructURBG()) {}
// Copy disallowed, move allowed.
NonsecureURBGBase(const NonsecureURBGBase&) = delete;
NonsecureURBGBase& operator=(const NonsecureURBGBase&) = delete;
NonsecureURBGBase(NonsecureURBGBase&&) = default;
NonsecureURBGBase& operator=(NonsecureURBGBase&&) = default;
// Constructor using a seed
template <class SSeq, typename = typename absl::enable_if_t<
!std::is_same<SSeq, NonsecureURBGBase>::value>>
explicit NonsecureURBGBase(SSeq&& seq)
: urbg_(ConstructURBG(std::forward<SSeq>(seq))) {}
// Note: on MSVC, min() or max() can be interpreted as MIN() or MAX(), so we
// enclose min() or max() in parens as (min)() and (max)().
// Additionally, clang-format requires no space before this construction.
// NonsecureURBGBase::min()
static constexpr result_type(min)() { return (URBG::min)(); }
// NonsecureURBGBase::max()
static constexpr result_type(max)() { return (URBG::max)(); }
// NonsecureURBGBase::operator()()
result_type operator()() { return urbg_(); }
// NonsecureURBGBase::discard()
void discard(unsigned long long values) { // NOLINT(runtime/int)
urbg_.discard(values);
}
bool operator==(const NonsecureURBGBase& other) const {
return urbg_ == other.urbg_;
}
bool operator!=(const NonsecureURBGBase& other) const {
return !(urbg_ == other.urbg_);
}
private:
// Seeder is a custom seed sequence type where generate() fills the provided
// buffer via the RandenPool entropy source.
struct Seeder {
using result_type = uint32_t;
size_t size() { return 0; }
template <typename OutIterator>
void param(OutIterator) const {}
template <typename RandomAccessIterator>
void generate(RandomAccessIterator begin, RandomAccessIterator end) {
if (begin != end) {
// begin, end must be random access iterators assignable from uint32_t.
generate_impl(
std::integral_constant<bool, sizeof(*begin) == sizeof(uint32_t)>{},
begin, end);
}
}
// Commonly, generate is invoked with a pointer to a buffer which
// can be cast to a uint32_t.
template <typename RandomAccessIterator>
void generate_impl(std::integral_constant<bool, true>,
RandomAccessIterator begin, RandomAccessIterator end) {
auto buffer = absl::MakeSpan(begin, end);
auto target = absl::MakeSpan(reinterpret_cast<uint32_t*>(buffer.data()),
buffer.size());
RandenPool<uint32_t>::Fill(target);
}
// The non-uint32_t case should be uncommon, and involves an extra copy,
// filling the uint32_t buffer and then mixing into the output.
template <typename RandomAccessIterator>
void generate_impl(std::integral_constant<bool, false>,
RandomAccessIterator begin, RandomAccessIterator end) {
const size_t n = std::distance(begin, end);
absl::InlinedVector<uint32_t, 8> data(n, 0);
RandenPool<uint32_t>::Fill(absl::MakeSpan(data.begin(), data.end()));
std::copy(std::begin(data), std::end(data), begin);
}
};
static URBG ConstructURBG() {
Seeder seeder;
return URBG(seeder);
}
template <typename SSeq>
static URBG ConstructURBG(SSeq&& seq) { // NOLINT(runtime/references)
auto salted_seq =
random_internal::MakeSaltedSeedSeq(std::forward<SSeq>(seq));
return URBG(salted_seq);
}
URBG urbg_;
};
} // namespace random_internal
} // namespace absl
#endif // ABSL_RANDOM_INTERNAL_NONSECURE_BASE_H_