chore(3p/abseil_cpp): unvendor abseil_cpp r/3786

we weren't actually using these sources anymore, okay?

Change-Id: If701571d9716de308d3512e1eb22c35db0877a66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5248
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>

1 files changed, 0 insertions, 230 deletions

diff --git a/third_party/abseil_cpp/absl/random/internal/randen_engine.h b/third_party/abseil_cpp/absl/random/internal/randen_engine.h
deleted file mode 100644
index 6b33731336e7..000000000000
--- a/third_party/abseil_cpp/absl/random/internal/randen_engine.h
+++ /dev/null
@@ -1,230 +0,0 @@
-// 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_RANDEN_ENGINE_H_
-#define ABSL_RANDOM_INTERNAL_RANDEN_ENGINE_H_
-
-#include <algorithm>
-#include <cinttypes>
-#include <cstdlib>
-#include <iostream>
-#include <iterator>
-#include <limits>
-#include <type_traits>
-
-#include "absl/meta/type_traits.h"
-#include "absl/random/internal/iostream_state_saver.h"
-#include "absl/random/internal/randen.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace random_internal {
-
-// Deterministic pseudorandom byte generator with backtracking resistance
-// (leaking the state does not compromise prior outputs). Based on Reverie
-// (see "A Robust and Sponge-Like PRNG with Improved Efficiency") instantiated
-// with an improved Simpira-like permutation.
-// Returns values of type "T" (must be a built-in unsigned integer type).
-//
-// RANDen = RANDom generator or beetroots in Swiss High German.
-// 'Strong' (well-distributed, unpredictable, backtracking-resistant) random
-// generator, faster in some benchmarks than std::mt19937_64 and pcg64_c32.
-template <typename T>
-class alignas(16) randen_engine {
- public:
-  // C++11 URBG interface:
-  using result_type = T;
-  static_assert(std::is_unsigned<result_type>::value,
-                "randen_engine template argument must be a built-in unsigned "
-                "integer type");
-
-  static constexpr result_type(min)() {
-    return (std::numeric_limits<result_type>::min)();
-  }
-
-  static constexpr result_type(max)() {
-    return (std::numeric_limits<result_type>::max)();
-  }
-
-  explicit randen_engine(result_type seed_value = 0) { seed(seed_value); }
-
-  template <class SeedSequence,
-            typename = typename absl::enable_if_t<
-                !std::is_same<SeedSequence, randen_engine>::value>>
-  explicit randen_engine(SeedSequence&& seq) {
-    seed(seq);
-  }
-
-  randen_engine(const randen_engine&) = default;
-
-  // Returns random bits from the buffer in units of result_type.
-  result_type operator()() {
-    // Refill the buffer if needed (unlikely).
-    if (next_ >= kStateSizeT) {
-      next_ = kCapacityT;
-      impl_.Generate(state_);
-    }
-
-    return state_[next_++];
-  }
-
-  template <class SeedSequence>
-  typename absl::enable_if_t<
-      !std::is_convertible<SeedSequence, result_type>::value>
-  seed(SeedSequence&& seq) {
-    // Zeroes the state.
-    seed();
-    reseed(seq);
-  }
-
-  void seed(result_type seed_value = 0) {
-    next_ = kStateSizeT;
-    // Zeroes the inner state and fills the outer state with seed_value to
-    // mimics behaviour of reseed
-    std::fill(std::begin(state_), std::begin(state_) + kCapacityT, 0);
-    std::fill(std::begin(state_) + kCapacityT, std::end(state_), seed_value);
-  }
-
-  // Inserts entropy into (part of) the state. Calling this periodically with
-  // sufficient entropy ensures prediction resistance (attackers cannot predict
-  // future outputs even if state is compromised).
-  template <class SeedSequence>
-  void reseed(SeedSequence& seq) {
-    using sequence_result_type = typename SeedSequence::result_type;
-    static_assert(sizeof(sequence_result_type) == 4,
-                  "SeedSequence::result_type must be 32-bit");
-
-    constexpr size_t kBufferSize =
-        Randen::kSeedBytes / sizeof(sequence_result_type);
-    alignas(16) sequence_result_type buffer[kBufferSize];
-
-    // Randen::Absorb XORs the seed into state, which is then mixed by a call
-    // to Randen::Generate. Seeding with only the provided entropy is preferred
-    // to using an arbitrary generate() call, so use [rand.req.seed_seq]
-    // size as a proxy for the number of entropy units that can be generated
-    // without relying on seed sequence mixing...
-    const size_t entropy_size = seq.size();
-    if (entropy_size < kBufferSize) {
-      // ... and only request that many values, or 256-bits, when unspecified.
-      const size_t requested_entropy = (entropy_size == 0) ? 8u : entropy_size;
-      std::fill(std::begin(buffer) + requested_entropy, std::end(buffer), 0);
-      seq.generate(std::begin(buffer), std::begin(buffer) + requested_entropy);
-      // The Randen paper suggests preferentially initializing even-numbered
-      // 128-bit vectors of the randen state (there are 16 such vectors).
-      // The seed data is merged into the state offset by 128-bits, which
-      // implies prefering seed bytes [16..31, ..., 208..223]. Since the
-      // buffer is 32-bit values, we swap the corresponding buffer positions in
-      // 128-bit chunks.
-      size_t dst = kBufferSize;
-      while (dst > 7) {
-        // leave the odd bucket as-is.
-        dst -= 4;
-        size_t src = dst >> 1;
-        // swap 128-bits into the even bucket
-        std::swap(buffer[--dst], buffer[--src]);
-        std::swap(buffer[--dst], buffer[--src]);
-        std::swap(buffer[--dst], buffer[--src]);
-        std::swap(buffer[--dst], buffer[--src]);
-      }
-    } else {
-      seq.generate(std::begin(buffer), std::end(buffer));
-    }
-    impl_.Absorb(buffer, state_);
-
-    // Generate will be called when operator() is called
-    next_ = kStateSizeT;
-  }
-
-  void discard(uint64_t count) {
-    uint64_t step = std::min<uint64_t>(kStateSizeT - next_, count);
-    count -= step;
-
-    constexpr uint64_t kRateT = kStateSizeT - kCapacityT;
-    while (count > 0) {
-      next_ = kCapacityT;
-      impl_.Generate(state_);
-      step = std::min<uint64_t>(kRateT, count);
-      count -= step;
-    }
-    next_ += step;
-  }
-
-  bool operator==(const randen_engine& other) const {
-    return next_ == other.next_ &&
-           std::equal(std::begin(state_), std::end(state_),
-                      std::begin(other.state_));
-  }
-
-  bool operator!=(const randen_engine& other) const {
-    return !(*this == other);
-  }
-
-  template <class CharT, class Traits>
-  friend std::basic_ostream<CharT, Traits>& operator<<(
-      std::basic_ostream<CharT, Traits>& os,  // NOLINT(runtime/references)
-      const randen_engine<T>& engine) {       // NOLINT(runtime/references)
-    using numeric_type =
-        typename random_internal::stream_format_type<result_type>::type;
-    auto saver = random_internal::make_ostream_state_saver(os);
-    for (const auto& elem : engine.state_) {
-      // In the case that `elem` is `uint8_t`, it must be cast to something
-      // larger so that it prints as an integer rather than a character. For
-      // simplicity, apply the cast all circumstances.
-      os << static_cast<numeric_type>(elem) << os.fill();
-    }
-    os << engine.next_;
-    return os;
-  }
-
-  template <class CharT, class Traits>
-  friend std::basic_istream<CharT, Traits>& operator>>(
-      std::basic_istream<CharT, Traits>& is,  // NOLINT(runtime/references)
-      randen_engine<T>& engine) {             // NOLINT(runtime/references)
-    using numeric_type =
-        typename random_internal::stream_format_type<result_type>::type;
-    result_type state[kStateSizeT];
-    size_t next;
-    for (auto& elem : state) {
-      // It is not possible to read uint8_t from wide streams, so it is
-      // necessary to read a wider type and then cast it to uint8_t.
-      numeric_type value;
-      is >> value;
-      elem = static_cast<result_type>(value);
-    }
-    is >> next;
-    if (is.fail()) {
-      return is;
-    }
-    std::memcpy(engine.state_, state, sizeof(engine.state_));
-    engine.next_ = next;
-    return is;
-  }
-
- private:
-  static constexpr size_t kStateSizeT =
-      Randen::kStateBytes / sizeof(result_type);
-  static constexpr size_t kCapacityT =
-      Randen::kCapacityBytes / sizeof(result_type);
-
-  // First kCapacityT are `inner', the others are accessible random bits.
-  alignas(16) result_type state_[kStateSizeT];
-  size_t next_;  // index within state_
-  Randen impl_;
-};
-
-}  // namespace random_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_RANDOM_INTERNAL_RANDEN_ENGINE_H_