summaryrefslogtreecommitdiff
path: root/absl/hash/internal
diff options
context:
space:
mode:
authorGravatar Abseil Team <absl-team@google.com>2018-12-04 11:01:12 -0800
committerGravatar Ashley Hedberg <ahedberg@google.com>2018-12-04 16:54:40 -0500
commitfcb104594b0bb4b8ac306cb2f55ecdad40974683 (patch)
treed2d79d246c6a894ca6716f47c15ebb7b8796b36a /absl/hash/internal
parent6c7de165d1c82684359ccb630bb5f83263fa5ebc (diff)
Creation of LTS branch "lts_2018_12_18"20181200
- 44b0fafc62d9b8f192e8180cbe9c4b806b339d57 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 926bfeb9fff223429c12224b7514243886323e8d Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 13327debebc5c2d1d4991b69fe50450e340e50e4 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 3088e76c597e068479e82508b1770a7ad0c806b6 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - f6ae816808cd913e0e2b3e2af14f328fa1071af0 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - a06c4a1d9093137b7217a5aaba8920d62e835dc0 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 7b46e1d31a6b08b1c6da2a13e7b151a20446fa07 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 070f6e47b33a2909d039e620c873204f78809492 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 7990fd459e9339467814ddb95000c87cb1e4d945 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - f95179062eb65ce40895cc76f1398cce25394369 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - cc8dcd307b76a575d2e3e0958a4fe4c7193c2f68 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - a705aa78dc76fc5c79d501e61dcc077eca68a8a4 Merge pull request #194 from Mizux/windows by Xiaoyi Zhang <zhangxy988@gmail.com> - a4c3ffff11eec0ee45742f915c255e9f870b7e0f Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 01174578651b73021d9b8c3820f6fea707dacdf0 Merge pull request #201 from ccawley2011/fix-byteswap by Matt Calabrese <38107210+mattcalabrese-google@users.noreply.github.com> - f86f9413856b65afdd61fea938d684b8ab73115a Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 94c298e2a0ae409e283cab96c954a685bd865a70 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 0884a6a04e4497d11b1b398cc0e422b118bf977a Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - c16d5557cd05119b5b7b1318ef778ebe3195b4a1 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 45221ccc4ed643e4209b0cc5798e97203f108fa8 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 2019e17a520575ab365b2b5134d71068182c70b8 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 5b70a8910b2e6fb0ce5193a41873139a126d2f7f Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - a00bdd176d66ef0b417d9576052a19091fbdf891 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - f340f773edab951656b19b6f1a77c964a78ec4c2 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 445998d7ac4e5d3c50411d377e3b50e960d2d6c2 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - e821380d69a549dc64900693942789d21aa4df5e Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - f21d187b80e3b7f08fb279775ea9c8b48c636030 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 5441bbe1db5d0f2ca24b5b60166367b0966790af Fix code snippet in comment (#174) by Loo Rong Jie <loorongjie@gmail.com> - 5aae0cffae8ffaacab965756169b34e511b353df Fix CMake build (#173) by Stephan Dollberg <stephan.dollberg@gmail.com> - 48cd2c3f351ff188bc85684b84a91b6e6d17d896 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - e291c279e458761e77a69b09b129d3d1e81f1e80 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - e01d95528ea2137a4a27a88d1f57c6cb260aafed Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 8ff1374008259719b54a8cb128ef951c02da164c Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 02451914b9ad5320f81f56a89f3eef1f8683227c Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 921fd5cf02ec0d665439a790148d59faa7d4a72c Merge pull request #166 from rongjiecomputer/cmake-test by Gennadiy Civil <gennadiycivil@users.noreply.github.com> - fb462224c058487763f263b7995d70efd0242c17 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - c075ad321696fa5072e097f0a51e4fe76a6fe13e Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 0f4bc966754ec6cd28d5f03467d56f1efdc598e3 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 6c7e5ffc43decd92f7bdfc510ad8a245a20b6dea Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - d6df769173bf0263489f98874b93034db0e479a2 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 28080f5f050c9530aa9f2b39c60d8217038d64ff Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 9c987f429bba32fb4446280fd3b91e2472d71d4d Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 5e7d459eeca7bc53deab0ee9634601386b53d7c0 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - bed5bd6e185c7e0311f3a1f2dab4c96083dac636 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - fefc83638fb69395d259ed245699310610429064 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - d8cfe9f2a77fbee02c09642491e62a3f3677e0f6 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - ad5c960b2eb914881d1ceba0e996a0a8f3f6ca59 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 86f0fe93ad9d6d033a319476736a3256369c1f75 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - f0f15c2778b0e4959244dd25e63f445a455870f5 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 29ff6d4860070bf8fcbd39c8805d0c32d56628a3 Removed "warning treated as error" flag from MSVC (#153) by vocaviking <vocaviking@users.noreply.github.com> - 083d04dd4a62ebbf037079b06e49b323c5e1192a Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - bea85b52733022294eef108a2e42d77b616ddca2 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 8f96be6ca60d967bd4b37f93d0a03bcff4145200 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 92e07e5590752d6b8e67f7f2f86c6286561e8cea Merge pull request #152 from clnperez/fix-multi-defines-p... by Derek Mauro <761129+derekmauro@users.noreply.github.com> - 2125e6444a9de9e41f21ecdc674dd7d8759c149d Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 9acad869d21731f5bc50430a33fe61cc0ffcbb0b Merge pull request #150 from OlafvdSpek/patch-2 by Jonathan Cohen <cohenjon@google.com> - c2e00d341913bf03b4597ade5b056042e23e8c58 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 9e060686d1c325f34f9806b45fe77bafeed00aee Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 7aa411ceafc1272a28579cca739a97a2fb79055a Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 2c5af55ed34850d8b7dd46177c8ca53fdfda920e Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 44aa275286baf97fc13529aca547a88b180beb08 Merge pull request #143 from rongjiecomputer/kernel by Xiaoyi Zhang <zhangxy988@gmail.com> - 42f22a28401c952f1fc5942231c7fdac80811bf5 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - b973bc53ef366f0253b85eeed9a79b241884a843 Merge pull request #139 from siepkes/smartos-support by ahedberg <ahedberg@google.com> - e0def7473e52336f58759e11db4cd9467e5e0356 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - f826f1d489b61b64df1d94afbe5981841a82e5fa Merge pull request #138 from edbaunton/remove-deprecated-... by ahedberg <ahedberg@google.com> - 7b50a4a94b0c7df68b3a854c850b551aaef0a8b4 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - a5030ca5125b9d557ecfeea8acc8b1a8e49f6d27 Merge pull request #144 from rongjiecomputer/winsock2 by Xiaoyi Zhang <zhangxy988@gmail.com> - 02687955b7ca8fc02ada9b14bc247deeb108d341 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 8f612ebb152fb7e05643a2bcf78cb89a8c0641ad Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 134496a31d8b324f762de3bee9a002658c984456 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - ba8d6cf07766263723e86736f20a51c1c9c67b19 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - be1e84b988fceabcea4fc9e93f899539f0c81901 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 16ac2ec2e38cdf47f9330a312e319d57da659c10 Merge pull request #134 from rongjiecomputer/cmake by Alex Strelnikov <strel@google.com> - 7efd8dc0f1075356e9c7caa950afd1ecf854e8b9 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 87a4c07856e7dc69958019d47b2f02ae47746ec0 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> - 4491d606df34c44efda47b6d17b605262f17e182 Export of internal Abseil changes. by Abseil Team <absl-team@google.com> GitOrigin-RevId: 44b0fafc62d9b8f192e8180cbe9c4b806b339d57 Change-Id: I2c427b5b41b2d34101922048b00f3d9dafcb498d
Diffstat (limited to 'absl/hash/internal')
-rw-r--r--absl/hash/internal/city.cc346
-rw-r--r--absl/hash/internal/city.h94
-rw-r--r--absl/hash/internal/city_test.cc595
-rw-r--r--absl/hash/internal/hash.cc25
-rw-r--r--absl/hash/internal/hash.h898
-rw-r--r--absl/hash/internal/print_hash_of.cc23
-rw-r--r--absl/hash/internal/spy_hash_state.h220
7 files changed, 2201 insertions, 0 deletions
diff --git a/absl/hash/internal/city.cc b/absl/hash/internal/city.cc
new file mode 100644
index 00000000..5c076fb5
--- /dev/null
+++ b/absl/hash/internal/city.cc
@@ -0,0 +1,346 @@
+// 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.
+//
+// This file provides CityHash64() and related functions.
+//
+// It's probably possible to create even faster hash functions by
+// writing a program that systematically explores some of the space of
+// possible hash functions, by using SIMD instructions, or by
+// compromising on hash quality.
+
+#include "absl/hash/internal/city.h"
+
+#include <string.h> // for memcpy and memset
+#include <algorithm>
+
+#include "absl/base/config.h"
+#include "absl/base/internal/endian.h"
+#include "absl/base/internal/unaligned_access.h"
+#include "absl/base/optimization.h"
+
+namespace absl {
+inline namespace lts_2018_12_18 {
+namespace hash_internal {
+
+#ifdef ABSL_IS_BIG_ENDIAN
+#define uint32_in_expected_order(x) (absl::gbswap_32(x))
+#define uint64_in_expected_order(x) (absl::gbswap_64(x))
+#else
+#define uint32_in_expected_order(x) (x)
+#define uint64_in_expected_order(x) (x)
+#endif
+
+static uint64_t Fetch64(const char *p) {
+ return uint64_in_expected_order(ABSL_INTERNAL_UNALIGNED_LOAD64(p));
+}
+
+static uint32_t Fetch32(const char *p) {
+ return uint32_in_expected_order(ABSL_INTERNAL_UNALIGNED_LOAD32(p));
+}
+
+// Some primes between 2^63 and 2^64 for various uses.
+static const uint64_t k0 = 0xc3a5c85c97cb3127ULL;
+static const uint64_t k1 = 0xb492b66fbe98f273ULL;
+static const uint64_t k2 = 0x9ae16a3b2f90404fULL;
+
+// Magic numbers for 32-bit hashing. Copied from Murmur3.
+static const uint32_t c1 = 0xcc9e2d51;
+static const uint32_t c2 = 0x1b873593;
+
+// A 32-bit to 32-bit integer hash copied from Murmur3.
+static uint32_t fmix(uint32_t h) {
+ h ^= h >> 16;
+ h *= 0x85ebca6b;
+ h ^= h >> 13;
+ h *= 0xc2b2ae35;
+ h ^= h >> 16;
+ return h;
+}
+
+static uint32_t Rotate32(uint32_t val, int shift) {
+ // Avoid shifting by 32: doing so yields an undefined result.
+ return shift == 0 ? val : ((val >> shift) | (val << (32 - shift)));
+}
+
+#undef PERMUTE3
+#define PERMUTE3(a, b, c) \
+ do { \
+ std::swap(a, b); \
+ std::swap(a, c); \
+ } while (0)
+
+static uint32_t Mur(uint32_t a, uint32_t h) {
+ // Helper from Murmur3 for combining two 32-bit values.
+ a *= c1;
+ a = Rotate32(a, 17);
+ a *= c2;
+ h ^= a;
+ h = Rotate32(h, 19);
+ return h * 5 + 0xe6546b64;
+}
+
+static uint32_t Hash32Len13to24(const char *s, size_t len) {
+ uint32_t a = Fetch32(s - 4 + (len >> 1));
+ uint32_t b = Fetch32(s + 4);
+ uint32_t c = Fetch32(s + len - 8);
+ uint32_t d = Fetch32(s + (len >> 1));
+ uint32_t e = Fetch32(s);
+ uint32_t f = Fetch32(s + len - 4);
+ uint32_t h = len;
+
+ return fmix(Mur(f, Mur(e, Mur(d, Mur(c, Mur(b, Mur(a, h)))))));
+}
+
+static uint32_t Hash32Len0to4(const char *s, size_t len) {
+ uint32_t b = 0;
+ uint32_t c = 9;
+ for (size_t i = 0; i < len; i++) {
+ signed char v = s[i];
+ b = b * c1 + v;
+ c ^= b;
+ }
+ return fmix(Mur(b, Mur(len, c)));
+}
+
+static uint32_t Hash32Len5to12(const char *s, size_t len) {
+ uint32_t a = len, b = len * 5, c = 9, d = b;
+ a += Fetch32(s);
+ b += Fetch32(s + len - 4);
+ c += Fetch32(s + ((len >> 1) & 4));
+ return fmix(Mur(c, Mur(b, Mur(a, d))));
+}
+
+uint32_t CityHash32(const char *s, size_t len) {
+ if (len <= 24) {
+ return len <= 12
+ ? (len <= 4 ? Hash32Len0to4(s, len) : Hash32Len5to12(s, len))
+ : Hash32Len13to24(s, len);
+ }
+
+ // len > 24
+ uint32_t h = len, g = c1 * len, f = g;
+
+ uint32_t a0 = Rotate32(Fetch32(s + len - 4) * c1, 17) * c2;
+ uint32_t a1 = Rotate32(Fetch32(s + len - 8) * c1, 17) * c2;
+ uint32_t a2 = Rotate32(Fetch32(s + len - 16) * c1, 17) * c2;
+ uint32_t a3 = Rotate32(Fetch32(s + len - 12) * c1, 17) * c2;
+ uint32_t a4 = Rotate32(Fetch32(s + len - 20) * c1, 17) * c2;
+ h ^= a0;
+ h = Rotate32(h, 19);
+ h = h * 5 + 0xe6546b64;
+ h ^= a2;
+ h = Rotate32(h, 19);
+ h = h * 5 + 0xe6546b64;
+ g ^= a1;
+ g = Rotate32(g, 19);
+ g = g * 5 + 0xe6546b64;
+ g ^= a3;
+ g = Rotate32(g, 19);
+ g = g * 5 + 0xe6546b64;
+ f += a4;
+ f = Rotate32(f, 19);
+ f = f * 5 + 0xe6546b64;
+ size_t iters = (len - 1) / 20;
+ do {
+ uint32_t b0 = Rotate32(Fetch32(s) * c1, 17) * c2;
+ uint32_t b1 = Fetch32(s + 4);
+ uint32_t b2 = Rotate32(Fetch32(s + 8) * c1, 17) * c2;
+ uint32_t b3 = Rotate32(Fetch32(s + 12) * c1, 17) * c2;
+ uint32_t b4 = Fetch32(s + 16);
+ h ^= b0;
+ h = Rotate32(h, 18);
+ h = h * 5 + 0xe6546b64;
+ f += b1;
+ f = Rotate32(f, 19);
+ f = f * c1;
+ g += b2;
+ g = Rotate32(g, 18);
+ g = g * 5 + 0xe6546b64;
+ h ^= b3 + b1;
+ h = Rotate32(h, 19);
+ h = h * 5 + 0xe6546b64;
+ g ^= b4;
+ g = absl::gbswap_32(g) * 5;
+ h += b4 * 5;
+ h = absl::gbswap_32(h);
+ f += b0;
+ PERMUTE3(f, h, g);
+ s += 20;
+ } while (--iters != 0);
+ g = Rotate32(g, 11) * c1;
+ g = Rotate32(g, 17) * c1;
+ f = Rotate32(f, 11) * c1;
+ f = Rotate32(f, 17) * c1;
+ h = Rotate32(h + g, 19);
+ h = h * 5 + 0xe6546b64;
+ h = Rotate32(h, 17) * c1;
+ h = Rotate32(h + f, 19);
+ h = h * 5 + 0xe6546b64;
+ h = Rotate32(h, 17) * c1;
+ return h;
+}
+
+// Bitwise right rotate. Normally this will compile to a single
+// instruction, especially if the shift is a manifest constant.
+static uint64_t Rotate(uint64_t val, int shift) {
+ // Avoid shifting by 64: doing so yields an undefined result.
+ return shift == 0 ? val : ((val >> shift) | (val << (64 - shift)));
+}
+
+static uint64_t ShiftMix(uint64_t val) { return val ^ (val >> 47); }
+
+static uint64_t HashLen16(uint64_t u, uint64_t v) {
+ return Hash128to64(uint128(u, v));
+}
+
+static uint64_t HashLen16(uint64_t u, uint64_t v, uint64_t mul) {
+ // Murmur-inspired hashing.
+ uint64_t a = (u ^ v) * mul;
+ a ^= (a >> 47);
+ uint64_t b = (v ^ a) * mul;
+ b ^= (b >> 47);
+ b *= mul;
+ return b;
+}
+
+static uint64_t HashLen0to16(const char *s, size_t len) {
+ if (len >= 8) {
+ uint64_t mul = k2 + len * 2;
+ uint64_t a = Fetch64(s) + k2;
+ uint64_t b = Fetch64(s + len - 8);
+ uint64_t c = Rotate(b, 37) * mul + a;
+ uint64_t d = (Rotate(a, 25) + b) * mul;
+ return HashLen16(c, d, mul);
+ }
+ if (len >= 4) {
+ uint64_t mul = k2 + len * 2;
+ uint64_t a = Fetch32(s);
+ return HashLen16(len + (a << 3), Fetch32(s + len - 4), mul);
+ }
+ if (len > 0) {
+ uint8_t a = s[0];
+ uint8_t b = s[len >> 1];
+ uint8_t c = s[len - 1];
+ uint32_t y = static_cast<uint32_t>(a) + (static_cast<uint32_t>(b) << 8);
+ uint32_t z = len + (static_cast<uint32_t>(c) << 2);
+ return ShiftMix(y * k2 ^ z * k0) * k2;
+ }
+ return k2;
+}
+
+// This probably works well for 16-byte strings as well, but it may be overkill
+// in that case.
+static uint64_t HashLen17to32(const char *s, size_t len) {
+ uint64_t mul = k2 + len * 2;
+ uint64_t a = Fetch64(s) * k1;
+ uint64_t b = Fetch64(s + 8);
+ uint64_t c = Fetch64(s + len - 8) * mul;
+ uint64_t d = Fetch64(s + len - 16) * k2;
+ return HashLen16(Rotate(a + b, 43) + Rotate(c, 30) + d,
+ a + Rotate(b + k2, 18) + c, mul);
+}
+
+// Return a 16-byte hash for 48 bytes. Quick and dirty.
+// Callers do best to use "random-looking" values for a and b.
+static std::pair<uint64_t, uint64_t> WeakHashLen32WithSeeds(uint64_t w, uint64_t x,
+ uint64_t y, uint64_t z,
+ uint64_t a, uint64_t b) {
+ a += w;
+ b = Rotate(b + a + z, 21);
+ uint64_t c = a;
+ a += x;
+ a += y;
+ b += Rotate(a, 44);
+ return std::make_pair(a + z, b + c);
+}
+
+// Return a 16-byte hash for s[0] ... s[31], a, and b. Quick and dirty.
+static std::pair<uint64_t, uint64_t> WeakHashLen32WithSeeds(const char *s, uint64_t a,
+ uint64_t b) {
+ return WeakHashLen32WithSeeds(Fetch64(s), Fetch64(s + 8), Fetch64(s + 16),
+ Fetch64(s + 24), a, b);
+}
+
+// Return an 8-byte hash for 33 to 64 bytes.
+static uint64_t HashLen33to64(const char *s, size_t len) {
+ uint64_t mul = k2 + len * 2;
+ uint64_t a = Fetch64(s) * k2;
+ uint64_t b = Fetch64(s + 8);
+ uint64_t c = Fetch64(s + len - 24);
+ uint64_t d = Fetch64(s + len - 32);
+ uint64_t e = Fetch64(s + 16) * k2;
+ uint64_t f = Fetch64(s + 24) * 9;
+ uint64_t g = Fetch64(s + len - 8);
+ uint64_t h = Fetch64(s + len - 16) * mul;
+ uint64_t u = Rotate(a + g, 43) + (Rotate(b, 30) + c) * 9;
+ uint64_t v = ((a + g) ^ d) + f + 1;
+ uint64_t w = absl::gbswap_64((u + v) * mul) + h;
+ uint64_t x = Rotate(e + f, 42) + c;
+ uint64_t y = (absl::gbswap_64((v + w) * mul) + g) * mul;
+ uint64_t z = e + f + c;
+ a = absl::gbswap_64((x + z) * mul + y) + b;
+ b = ShiftMix((z + a) * mul + d + h) * mul;
+ return b + x;
+}
+
+uint64_t CityHash64(const char *s, size_t len) {
+ if (len <= 32) {
+ if (len <= 16) {
+ return HashLen0to16(s, len);
+ } else {
+ return HashLen17to32(s, len);
+ }
+ } else if (len <= 64) {
+ return HashLen33to64(s, len);
+ }
+
+ // For strings over 64 bytes we hash the end first, and then as we
+ // loop we keep 56 bytes of state: v, w, x, y, and z.
+ uint64_t x = Fetch64(s + len - 40);
+ uint64_t y = Fetch64(s + len - 16) + Fetch64(s + len - 56);
+ uint64_t z = HashLen16(Fetch64(s + len - 48) + len, Fetch64(s + len - 24));
+ std::pair<uint64_t, uint64_t> v = WeakHashLen32WithSeeds(s + len - 64, len, z);
+ std::pair<uint64_t, uint64_t> w = WeakHashLen32WithSeeds(s + len - 32, y + k1, x);
+ x = x * k1 + Fetch64(s);
+
+ // Decrease len to the nearest multiple of 64, and operate on 64-byte chunks.
+ len = (len - 1) & ~static_cast<size_t>(63);
+ do {
+ x = Rotate(x + y + v.first + Fetch64(s + 8), 37) * k1;
+ y = Rotate(y + v.second + Fetch64(s + 48), 42) * k1;
+ x ^= w.second;
+ y += v.first + Fetch64(s + 40);
+ z = Rotate(z + w.first, 33) * k1;
+ v = WeakHashLen32WithSeeds(s, v.second * k1, x + w.first);
+ w = WeakHashLen32WithSeeds(s + 32, z + w.second, y + Fetch64(s + 16));
+ std::swap(z, x);
+ s += 64;
+ len -= 64;
+ } while (len != 0);
+ return HashLen16(HashLen16(v.first, w.first) + ShiftMix(y) * k1 + z,
+ HashLen16(v.second, w.second) + x);
+}
+
+uint64_t CityHash64WithSeed(const char *s, size_t len, uint64_t seed) {
+ return CityHash64WithSeeds(s, len, k2, seed);
+}
+
+uint64_t CityHash64WithSeeds(const char *s, size_t len, uint64_t seed0,
+ uint64_t seed1) {
+ return HashLen16(CityHash64(s, len) - seed0, seed1);
+}
+
+} // namespace hash_internal
+} // inline namespace lts_2018_12_18
+} // namespace absl
diff --git a/absl/hash/internal/city.h b/absl/hash/internal/city.h
new file mode 100644
index 00000000..46c18ffa
--- /dev/null
+++ b/absl/hash/internal/city.h
@@ -0,0 +1,94 @@
+// 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.
+//
+// http://code.google.com/p/cityhash/
+//
+// This file provides a few functions for hashing strings. All of them are
+// high-quality functions in the sense that they pass standard tests such
+// as Austin Appleby's SMHasher. They are also fast.
+//
+// For 64-bit x86 code, on short strings, we don't know of anything faster than
+// CityHash64 that is of comparable quality. We believe our nearest competitor
+// is Murmur3. For 64-bit x86 code, CityHash64 is an excellent choice for hash
+// tables and most other hashing (excluding cryptography).
+//
+// For 32-bit x86 code, we don't know of anything faster than CityHash32 that
+// is of comparable quality. We believe our nearest competitor is Murmur3A.
+// (On 64-bit CPUs, it is typically faster to use the other CityHash variants.)
+//
+// Functions in the CityHash family are not suitable for cryptography.
+//
+// Please see CityHash's README file for more details on our performance
+// measurements and so on.
+//
+// WARNING: This code has been only lightly tested on big-endian platforms!
+// It is known to work well on little-endian platforms that have a small penalty
+// for unaligned reads, such as current Intel and AMD moderate-to-high-end CPUs.
+// It should work on all 32-bit and 64-bit platforms that allow unaligned reads;
+// bug reports are welcome.
+//
+// By the way, for some hash functions, given strings a and b, the hash
+// of a+b is easily derived from the hashes of a and b. This property
+// doesn't hold for any hash functions in this file.
+
+#ifndef ABSL_HASH_INTERNAL_CITY_H_
+#define ABSL_HASH_INTERNAL_CITY_H_
+
+#include <stdint.h>
+#include <stdlib.h> // for size_t.
+#include <utility>
+
+
+namespace absl {
+inline namespace lts_2018_12_18 {
+namespace hash_internal {
+
+typedef std::pair<uint64_t, uint64_t> uint128;
+
+inline uint64_t Uint128Low64(const uint128 &x) { return x.first; }
+inline uint64_t Uint128High64(const uint128 &x) { return x.second; }
+
+// Hash function for a byte array.
+uint64_t CityHash64(const char *s, size_t len);
+
+// Hash function for a byte array. For convenience, a 64-bit seed is also
+// hashed into the result.
+uint64_t CityHash64WithSeed(const char *s, size_t len, uint64_t seed);
+
+// Hash function for a byte array. For convenience, two seeds are also
+// hashed into the result.
+uint64_t CityHash64WithSeeds(const char *s, size_t len, uint64_t seed0,
+ uint64_t seed1);
+
+// Hash function for a byte array. Most useful in 32-bit binaries.
+uint32_t CityHash32(const char *s, size_t len);
+
+// Hash 128 input bits down to 64 bits of output.
+// This is intended to be a reasonably good hash function.
+inline uint64_t Hash128to64(const uint128 &x) {
+ // Murmur-inspired hashing.
+ const uint64_t kMul = 0x9ddfea08eb382d69ULL;
+ uint64_t a = (Uint128Low64(x) ^ Uint128High64(x)) * kMul;
+ a ^= (a >> 47);
+ uint64_t b = (Uint128High64(x) ^ a) * kMul;
+ b ^= (b >> 47);
+ b *= kMul;
+ return b;
+}
+
+} // namespace hash_internal
+} // inline namespace lts_2018_12_18
+} // namespace absl
+
+#endif // ABSL_HASH_INTERNAL_CITY_H_
diff --git a/absl/hash/internal/city_test.cc b/absl/hash/internal/city_test.cc
new file mode 100644
index 00000000..f305ed9e
--- /dev/null
+++ b/absl/hash/internal/city_test.cc
@@ -0,0 +1,595 @@
+// 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.
+
+#include "absl/hash/internal/city.h"
+
+#include <string.h>
+#include <cstdio>
+#include <iostream>
+#include "gtest/gtest.h"
+
+namespace absl {
+inline namespace lts_2018_12_18 {
+namespace hash_internal {
+
+static const uint64_t k0 = 0xc3a5c85c97cb3127ULL;
+static const uint64_t kSeed0 = 1234567;
+static const uint64_t kSeed1 = k0;
+static const int kDataSize = 1 << 20;
+static const int kTestSize = 300;
+
+static char data[kDataSize];
+
+// Initialize data to pseudorandom values.
+void setup() {
+ uint64_t a = 9;
+ uint64_t b = 777;
+ for (int i = 0; i < kDataSize; i++) {
+ a += b;
+ b += a;
+ a = (a ^ (a >> 41)) * k0;
+ b = (b ^ (b >> 41)) * k0 + i;
+ uint8_t u = b >> 37;
+ memcpy(data + i, &u, 1); // uint8_t -> char
+ }
+}
+
+#define C(x) 0x##x##ULL
+static const uint64_t testdata[kTestSize][4] = {
+ {C(9ae16a3b2f90404f), C(75106db890237a4a), C(3feac5f636039766),
+ C(dc56d17a)},
+ {C(541150e87f415e96), C(1aef0d24b3148a1a), C(bacc300e1e82345a),
+ C(99929334)},
+ {C(f3786a4b25827c1), C(34ee1a2bf767bd1c), C(2f15ca2ebfb631f2), C(4252edb7)},
+ {C(ef923a7a1af78eab), C(79163b1e1e9a9b18), C(df3b2aca6e1e4a30),
+ C(ebc34f3c)},
+ {C(11df592596f41d88), C(843ec0bce9042f9c), C(cce2ea1e08b1eb30),
+ C(26f2b463)},
+ {C(831f448bdc5600b3), C(62a24be3120a6919), C(1b44098a41e010da),
+ C(b042c047)},
+ {C(3eca803e70304894), C(d80de767e4a920a), C(a51cfbb292efd53d), C(e73bb0a8)},
+ {C(1b5a063fb4c7f9f1), C(318dbc24af66dee9), C(10ef7b32d5c719af),
+ C(91dfdd75)},
+ {C(a0f10149a0e538d6), C(69d008c20f87419f), C(41b36376185b3e9e),
+ C(c87f95de)},
+ {C(fb8d9c70660b910b), C(a45b0cc3476bff1b), C(b28d1996144f0207),
+ C(3f5538ef)},
+ {C(236827beae282a46), C(e43970221139c946), C(4f3ac6faa837a3aa),
+ C(70eb1a1f)},
+ {C(c385e435136ecf7c), C(d9d17368ff6c4a08), C(1b31eed4e5251a67),
+ C(cfd63b83)},
+ {C(e3f6828b6017086d), C(21b4d1900554b3b0), C(bef38be1809e24f1),
+ C(894a52ef)},
+ {C(851fff285561dca0), C(4d1277d73cdf416f), C(28ccffa61010ebe2),
+ C(9cde6a54)},
+ {C(61152a63595a96d9), C(d1a3a91ef3a7ba45), C(443b6bb4a493ad0c),
+ C(6c4898d5)},
+ {C(44473e03be306c88), C(30097761f872472a), C(9fd1b669bfad82d7),
+ C(13e1978e)},
+ {C(3ead5f21d344056), C(fb6420393cfb05c3), C(407932394cbbd303), C(51b4ba8)},
+ {C(6abbfde37ee03b5b), C(83febf188d2cc113), C(cda7b62d94d5b8ee),
+ C(b6b06e40)},
+ {C(943e7ed63b3c080), C(1ef207e9444ef7f8), C(ef4a9f9f8c6f9b4a), C(240a2f2)},
+ {C(d72ce05171ef8a1a), C(c6bd6bd869203894), C(c760e6396455d23a),
+ C(5dcefc30)},
+ {C(4182832b52d63735), C(337097e123eea414), C(b5a72ca0456df910),
+ C(7a48b105)},
+ {C(d6cdae892584a2cb), C(58de0fa4eca17dcd), C(43df30b8f5f1cb00),
+ C(fd55007b)},
+ {C(5c8e90bc267c5ee4), C(e9ae044075d992d9), C(f234cbfd1f0a1e59),
+ C(6b95894c)},
+ {C(bbd7f30ac310a6f3), C(b23b570d2666685f), C(fb13fb08c9814fe7),
+ C(3360e827)},
+ {C(36a097aa49519d97), C(8204380a73c4065), C(77c2004bdd9e276a), C(45177e0b)},
+ {C(dc78cb032c49217), C(112464083f83e03a), C(96ae53e28170c0f5), C(7c6fffe4)},
+ {C(441593e0da922dfe), C(936ef46061469b32), C(204a1921197ddd87),
+ C(bbc78da4)},
+ {C(2ba3883d71cc2133), C(72f2bbb32bed1a3c), C(27e1bd96d4843251),
+ C(c5c25d39)},
+ {C(f2b6d2adf8423600), C(7514e2f016a48722), C(43045743a50396ba),
+ C(b6e5d06e)},
+ {C(38fffe7f3680d63c), C(d513325255a7a6d1), C(31ed47790f6ca62f),
+ C(6178504e)},
+ {C(b7477bf0b9ce37c6), C(63b1c580a7fd02a4), C(f6433b9f10a5dac), C(bd4c3637)},
+ {C(55bdb0e71e3edebd), C(c7ab562bcf0568bc), C(43166332f9ee684f),
+ C(6e7ac474)},
+ {C(782fa1b08b475e7), C(fb7138951c61b23b), C(9829105e234fb11e), C(1fb4b518)},
+ {C(c5dc19b876d37a80), C(15ffcff666cfd710), C(e8c30c72003103e2),
+ C(31d13d6d)},
+ {C(5e1141711d2d6706), C(b537f6dee8de6933), C(3af0a1fbbe027c54),
+ C(26fa72e3)},
+ {C(782edf6da001234f), C(f48cbd5c66c48f3), C(808754d1e64e2a32), C(6a7433bf)},
+ {C(d26285842ff04d44), C(8f38d71341eacca9), C(5ca436f4db7a883c),
+ C(4e6df758)},
+ {C(c6ab830865a6bae6), C(6aa8e8dd4b98815c), C(efe3846713c371e5),
+ C(d57f63ea)},
+ {C(44b3a1929232892), C(61dca0e914fc217), C(a607cc142096b964), C(52ef73b3)},
+ {C(4b603d7932a8de4f), C(fae64c464b8a8f45), C(8fafab75661d602a), C(3cb36c3)},
+ {C(4ec0b54cf1566aff), C(30d2c7269b206bf4), C(77c22e82295e1061),
+ C(72c39bea)},
+ {C(ed8b7a4b34954ff7), C(56432de31f4ee757), C(85bd3abaa572b155),
+ C(a65aa25c)},
+ {C(5d28b43694176c26), C(714cc8bc12d060ae), C(3437726273a83fe6),
+ C(74740539)},
+ {C(6a1ef3639e1d202e), C(919bc1bd145ad928), C(30f3f7e48c28a773),
+ C(c3ae3c26)},
+ {C(159f4d9e0307b111), C(3e17914a5675a0c), C(af849bd425047b51), C(f29db8a2)},
+ {C(cc0a840725a7e25b), C(57c69454396e193a), C(976eaf7eee0b4540),
+ C(1ef4cbf4)},
+ {C(a2b27ee22f63c3f1), C(9ebde0ce1b3976b2), C(2fe6a92a257af308),
+ C(a9be6c41)},
+ {C(d8f2f234899bcab3), C(b10b037297c3a168), C(debea2c510ceda7f), C(fa31801)},
+ {C(584f28543864844f), C(d7cee9fc2d46f20d), C(a38dca5657387205),
+ C(8331c5d8)},
+ {C(a94be46dd9aa41af), C(a57e5b7723d3f9bd), C(34bf845a52fd2f), C(e9876db8)},
+ {C(9a87bea227491d20), C(a468657e2b9c43e7), C(af9ba60db8d89ef7),
+ C(27b0604e)},
+ {C(27688c24958d1a5c), C(e3b4a1c9429cf253), C(48a95811f70d64bc),
+ C(dcec07f2)},
+ {C(5d1d37790a1873ad), C(ed9cd4bcc5fa1090), C(ce51cde05d8cd96a),
+ C(cff0a82a)},
+ {C(1f03fd18b711eea9), C(566d89b1946d381a), C(6e96e83fc92563ab),
+ C(fec83621)},
+ {C(f0316f286cf527b6), C(f84c29538de1aa5a), C(7612ed3c923d4a71), C(743d8dc)},
+ {C(297008bcb3e3401d), C(61a8e407f82b0c69), C(a4a35bff0524fa0e),
+ C(64d41d26)},
+ {C(43c6252411ee3be), C(b4ca1b8077777168), C(2746dc3f7da1737f), C(acd90c81)},
+ {C(ce38a9a54fad6599), C(6d6f4a90b9e8755e), C(c3ecc79ff105de3f),
+ C(7c746a4b)},
+ {C(270a9305fef70cf), C(600193999d884f3a), C(f4d49eae09ed8a1), C(b1047e99)},
+ {C(e71be7c28e84d119), C(eb6ace59932736e6), C(70c4397807ba12c5),
+ C(d1fd1068)},
+ {C(b5b58c24b53aaa19), C(d2a6ab0773dd897f), C(ef762fe01ecb5b97),
+ C(56486077)},
+ {C(44dd59bd301995cf), C(3ccabd76493ada1a), C(540db4c87d55ef23),
+ C(6069be80)},
+ {C(b4d4789eb6f2630b), C(bf6973263ce8ef0e), C(d1c75c50844b9d3), C(2078359b)},
+ {C(12807833c463737c), C(58e927ea3b3776b4), C(72dd20ef1c2f8ad0),
+ C(9ea21004)},
+ {C(e88419922b87176f), C(bcf32f41a7ddbf6f), C(d6ebefd8085c1a0f),
+ C(9c9cfe88)},
+ {C(105191e0ec8f7f60), C(5918dbfcca971e79), C(6b285c8a944767b9),
+ C(b70a6ddd)},
+ {C(a5b88bf7399a9f07), C(fca3ddfd96461cc4), C(ebe738fdc0282fc6),
+ C(dea37298)},
+ {C(d08c3f5747d84f50), C(4e708b27d1b6f8ac), C(70f70fd734888606),
+ C(8f480819)},
+ {C(2f72d12a40044b4b), C(889689352fec53de), C(f03e6ad87eb2f36), C(30b3b16)},
+ {C(aa1f61fdc5c2e11e), C(c2c56cd11277ab27), C(a1e73069fdf1f94f),
+ C(f31bc4e8)},
+ {C(9489b36fe2246244), C(3355367033be74b8), C(5f57c2277cbce516),
+ C(419f953b)},
+ {C(358d7c0476a044cd), C(e0b7b47bcbd8854f), C(ffb42ec696705519),
+ C(20e9e76d)},
+ {C(b0c48df14275265a), C(9da4448975905efa), C(d716618e414ceb6d),
+ C(646f0ff8)},
+ {C(daa70bb300956588), C(410ea6883a240c6d), C(f5c8239fb5673eb3),
+ C(eeb7eca8)},
+ {C(4ec97a20b6c4c7c2), C(5913b1cd454f29fd), C(a9629f9daf06d685), C(8112bb9)},
+ {C(5c3323628435a2e8), C(1bea45ce9e72a6e3), C(904f0a7027ddb52e),
+ C(85a6d477)},
+ {C(c1ef26bea260abdb), C(6ee423f2137f9280), C(df2118b946ed0b43),
+ C(56f76c84)},
+ {C(6be7381b115d653a), C(ed046190758ea511), C(de6a45ffc3ed1159),
+ C(9af45d55)},
+ {C(ae3eece1711b2105), C(14fd3f4027f81a4a), C(abb7e45177d151db),
+ C(d1c33760)},
+ {C(376c28588b8fb389), C(6b045e84d8491ed2), C(4e857effb7d4e7dc),
+ C(c56bbf69)},
+ {C(58d943503bb6748f), C(419c6c8e88ac70f6), C(586760cbf3d3d368),
+ C(abecfb9b)},
+ {C(dfff5989f5cfd9a1), C(bcee2e7ea3a96f83), C(681c7874adb29017),
+ C(8de13255)},
+ {C(7fb19eb1a496e8f5), C(d49e5dfdb5c0833f), C(c0d5d7b2f7c48dc7),
+ C(a98ee299)},
+ {C(5dba5b0dadccdbaa), C(4ba8da8ded87fcdc), C(f693fdd25badf2f0),
+ C(3015f556)},
+ {C(688bef4b135a6829), C(8d31d82abcd54e8e), C(f95f8a30d55036d7),
+ C(5a430e29)},
+ {C(d8323be05433a412), C(8d48fa2b2b76141d), C(3d346f23978336a5),
+ C(2797add0)},
+ {C(3b5404278a55a7fc), C(23ca0b327c2d0a81), C(a6d65329571c892c),
+ C(27d55016)},
+ {C(2a96a3f96c5e9bbc), C(8caf8566e212dda8), C(904de559ca16e45e),
+ C(84945a82)},
+ {C(22bebfdcc26d18ff), C(4b4d8dcb10807ba1), C(40265eee30c6b896),
+ C(3ef7e224)},
+ {C(627a2249ec6bbcc2), C(c0578b462a46735a), C(4974b8ee1c2d4f1f),
+ C(35ed8dc8)},
+ {C(3abaf1667ba2f3e0), C(ee78476b5eeadc1), C(7e56ac0a6ca4f3f4), C(6a75e43d)},
+ {C(3931ac68c5f1b2c9), C(efe3892363ab0fb0), C(40b707268337cd36),
+ C(235d9805)},
+ {C(b98fb0606f416754), C(46a6e5547ba99c1e), C(c909d82112a8ed2), C(f7d69572)},
+ {C(7f7729a33e58fcc4), C(2e4bc1e7a023ead4), C(e707008ea7ca6222),
+ C(bacd0199)},
+ {C(42a0aa9ce82848b3), C(57232730e6bee175), C(f89bb3f370782031),
+ C(e428f50e)},
+ {C(6b2c6d38408a4889), C(de3ef6f68fb25885), C(20754f456c203361),
+ C(81eaaad3)},
+ {C(930380a3741e862a), C(348d28638dc71658), C(89dedcfd1654ea0d),
+ C(addbd3e3)},
+ {C(94808b5d2aa25f9a), C(cec72968128195e0), C(d9f4da2bdc1e130f),
+ C(e66dbca0)},
+ {C(b31abb08ae6e3d38), C(9eb9a95cbd9e8223), C(8019e79b7ee94ea9),
+ C(afe11fd5)},
+ {C(dccb5534a893ea1a), C(ce71c398708c6131), C(fe2396315457c164),
+ C(a71a406f)},
+ {C(6369163565814de6), C(8feb86fb38d08c2f), C(4976933485cc9a20),
+ C(9d90eaf5)},
+ {C(edee4ff253d9f9b3), C(96ef76fb279ef0ad), C(a4d204d179db2460),
+ C(6665db10)},
+ {C(941993df6e633214), C(929bc1beca5b72c6), C(141fc52b8d55572d),
+ C(9c977cbf)},
+ {C(859838293f64cd4c), C(484403b39d44ad79), C(bf674e64d64b9339),
+ C(ee83ddd4)},
+ {C(c19b5648e0d9f555), C(328e47b2b7562993), C(e756b92ba4bd6a51), C(26519cc)},
+ {C(f963b63b9006c248), C(9e9bf727ffaa00bc), C(c73bacc75b917e3a),
+ C(a485a53f)},
+ {C(6a8aa0852a8c1f3b), C(c8f1e5e206a21016), C(2aa554aed1ebb524),
+ C(f62bc412)},
+ {C(740428b4d45e5fb8), C(4c95a4ce922cb0a5), C(e99c3ba78feae796),
+ C(8975a436)},
+ {C(658b883b3a872b86), C(2f0e303f0f64827a), C(975337e23dc45e1), C(94ff7f41)},
+ {C(6df0a977da5d27d4), C(891dd0e7cb19508), C(fd65434a0b71e680), C(760aa031)},
+ {C(a900275464ae07ef), C(11f2cfda34beb4a3), C(9abf91e5a1c38e4), C(3bda76df)},
+ {C(810bc8aa0c40bcb0), C(448a019568d01441), C(f60ec52f60d3aeae),
+ C(498e2e65)},
+ {C(22036327deb59ed7), C(adc05ceb97026a02), C(48bff0654262672b),
+ C(d38deb48)},
+ {C(7d14dfa9772b00c8), C(595735efc7eeaed7), C(29872854f94c3507),
+ C(82b3fb6b)},
+ {C(2d777cddb912675d), C(278d7b10722a13f9), C(f5c02bfb7cc078af),
+ C(e500e25f)},
+ {C(f2ec98824e8aa613), C(5eb7e3fb53fe3bed), C(12c22860466e1dd4),
+ C(bd2bb07c)},
+ {C(5e763988e21f487f), C(24189de8065d8dc5), C(d1519d2403b62aa0),
+ C(3a2b431d)},
+ {C(48949dc327bb96ad), C(e1fd21636c5c50b4), C(3f6eb7f13a8712b4),
+ C(7322a83d)},
+ {C(b7c4209fb24a85c5), C(b35feb319c79ce10), C(f0d3de191833b922),
+ C(a645ca1c)},
+ {C(9c9e5be0943d4b05), C(b73dc69e45201cbb), C(aab17180bfe5083d),
+ C(8909a45a)},
+ {C(3898bca4dfd6638d), C(f911ff35efef0167), C(24bdf69e5091fc88),
+ C(bd30074c)},
+ {C(5b5d2557400e68e7), C(98d610033574cee), C(dfd08772ce385deb), C(c17cf001)},
+ {C(a927ed8b2bf09bb6), C(606e52f10ae94eca), C(71c2203feb35a9ee),
+ C(26ffd25a)},
+ {C(8d25746414aedf28), C(34b1629d28b33d3a), C(4d5394aea5f82d7b),
+ C(f1d8ce3c)},
+ {C(b5bbdb73458712f2), C(1ff887b3c2a35137), C(7f7231f702d0ace9),
+ C(3ee8fb17)},
+ {C(3d32a26e3ab9d254), C(fc4070574dc30d3a), C(f02629579c2b27c9),
+ C(a77acc2a)},
+ {C(9371d3c35fa5e9a5), C(42967cf4d01f30), C(652d1eeae704145c), C(f4556dee)},
+ {C(cbaa3cb8f64f54e0), C(76c3b48ee5c08417), C(9f7d24e87e61ce9), C(de287a64)},
+ {C(b2e23e8116c2ba9f), C(7e4d9c0060101151), C(3310da5e5028f367),
+ C(878e55b9)},
+ {C(8aa77f52d7868eb9), C(4d55bd587584e6e2), C(d2db37041f495f5), C(7648486)},
+ {C(858fea922c7fe0c3), C(cfe8326bf733bc6f), C(4e5e2018cf8f7dfc),
+ C(57ac0fb1)},
+ {C(46ef25fdec8392b1), C(e48d7b6d42a5cd35), C(56a6fe1c175299ca),
+ C(d01967ca)},
+ {C(8d078f726b2df464), C(b50ee71cdcabb299), C(f4af300106f9c7ba),
+ C(96ecdf74)},
+ {C(35ea86e6960ca950), C(34fe1fe234fc5c76), C(a00207a3dc2a72b7),
+ C(779f5506)},
+ {C(8aee9edbc15dd011), C(51f5839dc8462695), C(b2213e17c37dca2d),
+ C(3c94c2de)},
+ {C(c3e142ba98432dda), C(911d060cab126188), C(b753fbfa8365b844),
+ C(39f98faf)},
+ {C(123ba6b99c8cd8db), C(448e582672ee07c4), C(cebe379292db9e65),
+ C(7af31199)},
+ {C(ba87acef79d14f53), C(b3e0fcae63a11558), C(d5ac313a593a9f45),
+ C(e341a9d6)},
+ {C(bcd3957d5717dc3), C(2da746741b03a007), C(873816f4b1ece472), C(ca24aeeb)},
+ {C(61442ff55609168e), C(6447c5fc76e8c9cf), C(6a846de83ae15728),
+ C(b2252b57)},
+ {C(dbe4b1b2d174757f), C(506512da18712656), C(6857f3e0b8dd95f), C(72c81da1)},
+ {C(531e8e77b363161c), C(eece0b43e2dae030), C(8294b82c78f34ed1),
+ C(6b9fce95)},
+ {C(f71e9c926d711e2b), C(d77af2853a4ceaa1), C(9aa0d6d76a36fae7),
+ C(19399857)},
+ {C(cb20ac28f52df368), C(e6705ee7880996de), C(9b665cc3ec6972f2),
+ C(3c57a994)},
+ {C(e4a794b4acb94b55), C(89795358057b661b), C(9c4cdcec176d7a70),
+ C(c053e729)},
+ {C(cb942e91443e7208), C(e335de8125567c2a), C(d4d74d268b86df1f),
+ C(51cbbba7)},
+ {C(ecca7563c203f7ba), C(177ae2423ef34bb2), C(f60b7243400c5731),
+ C(1acde79a)},
+ {C(1652cb940177c8b5), C(8c4fe7d85d2a6d6d), C(f6216ad097e54e72),
+ C(2d160d13)},
+ {C(31fed0fc04c13ce8), C(3d5d03dbf7ff240a), C(727c5c9b51581203),
+ C(787f5801)},
+ {C(e7b668947590b9b3), C(baa41ad32938d3fa), C(abcbc8d4ca4b39e4),
+ C(c9629828)},
+ {C(1de2119923e8ef3c), C(6ab27c096cf2fe14), C(8c3658edca958891),
+ C(be139231)},
+ {C(1269df1e69e14fa7), C(992f9d58ac5041b7), C(e97fcf695a7cbbb4),
+ C(7df699ef)},
+ {C(820826d7aba567ff), C(1f73d28e036a52f3), C(41c4c5a73f3b0893),
+ C(8ce6b96d)},
+ {C(ffe0547e4923cef9), C(3534ed49b9da5b02), C(548a273700fba03d),
+ C(6f9ed99c)},
+ {C(72da8d1b11d8bc8b), C(ba94b56b91b681c6), C(4e8cc51bd9b0fc8c),
+ C(e0244796)},
+ {C(d62ab4e3f88fc797), C(ea86c7aeb6283ae4), C(b5b93e09a7fe465), C(4ccf7e75)},
+ {C(d0f06c28c7b36823), C(1008cb0874de4bb8), C(d6c7ff816c7a737b),
+ C(915cef86)},
+ {C(99b7042460d72ec6), C(2a53e5e2b8e795c2), C(53a78132d9e1b3e3),
+ C(5cb59482)},
+ {C(4f4dfcfc0ec2bae5), C(841233148268a1b8), C(9248a76ab8be0d3), C(6ca3f532)},
+ {C(fe86bf9d4422b9ae), C(ebce89c90641ef9c), C(1c84e2292c0b5659),
+ C(e24f3859)},
+ {C(a90d81060932dbb0), C(8acfaa88c5fbe92b), C(7c6f3447e90f7f3f),
+ C(adf5a9c7)},
+ {C(17938a1b0e7f5952), C(22cadd2f56f8a4be), C(84b0d1183d5ed7c1),
+ C(32264b75)},
+ {C(de9e0cb0e16f6e6d), C(238e6283aa4f6594), C(4fb9c914c2f0a13b),
+ C(a64b3376)},
+ {C(6d4b876d9b146d1a), C(aab2d64ce8f26739), C(d315f93600e83fe5), C(d33890e)},
+ {C(e698fa3f54e6ea22), C(bd28e20e7455358c), C(9ace161f6ea76e66),
+ C(926d4b63)},
+ {C(7bc0deed4fb349f7), C(1771aff25dc722fa), C(19ff0644d9681917),
+ C(d51ba539)},
+ {C(db4b15e88533f622), C(256d6d2419b41ce9), C(9d7c5378396765d5),
+ C(7f37636d)},
+ {C(922834735e86ecb2), C(363382685b88328e), C(e9c92960d7144630),
+ C(b98026c0)},
+ {C(30f1d72c812f1eb8), C(b567cd4a69cd8989), C(820b6c992a51f0bc),
+ C(b877767e)},
+ {C(168884267f3817e9), C(5b376e050f637645), C(1c18314abd34497a), C(aefae77)},
+ {C(82e78596ee3e56a7), C(25697d9c87f30d98), C(7600a8342834924d), C(f686911)},
+ {C(aa2d6cf22e3cc252), C(9b4dec4f5e179f16), C(76fb0fba1d99a99a),
+ C(3deadf12)},
+ {C(7bf5ffd7f69385c7), C(fc077b1d8bc82879), C(9c04e36f9ed83a24),
+ C(ccf02a4e)},
+ {C(e89c8ff9f9c6e34b), C(f54c0f669a49f6c4), C(fc3e46f5d846adef),
+ C(176c1722)},
+ {C(a18fbcdccd11e1f4), C(8248216751dfd65e), C(40c089f208d89d7c), C(26f82ad)},
+ {C(2d54f40cc4088b17), C(59d15633b0cd1399), C(a8cc04bb1bffd15b),
+ C(b5244f42)},
+ {C(69276946cb4e87c7), C(62bdbe6183be6fa9), C(3ba9773dac442a1a),
+ C(49a689e5)},
+ {C(668174a3f443df1d), C(407299392da1ce86), C(c2a3f7d7f2c5be28), C(59fcdd3)},
+ {C(5e29be847bd5046), C(b561c7f19c8f80c3), C(5e5abd5021ccaeaf), C(4f4b04e9)},
+ {C(cd0d79f2164da014), C(4c386bb5c5d6ca0c), C(8e771b03647c3b63),
+ C(8b00f891)},
+ {C(e0e6fc0b1628af1d), C(29be5fb4c27a2949), C(1c3f781a604d3630),
+ C(16e114f3)},
+ {C(2058927664adfd93), C(6e8f968c7963baa5), C(af3dced6fff7c394),
+ C(d6b6dadc)},
+ {C(dc107285fd8e1af7), C(a8641a0609321f3f), C(db06e89ffdc54466),
+ C(897e20ac)},
+ {C(fbba1afe2e3280f1), C(755a5f392f07fce), C(9e44a9a15402809a), C(f996e05d)},
+ {C(bfa10785ddc1011b), C(b6e1c4d2f670f7de), C(517d95604e4fcc1f),
+ C(c4306af6)},
+ {C(534cc35f0ee1eb4e), C(b703820f1f3b3dce), C(884aa164cf22363), C(6dcad433)},
+ {C(7ca6e3933995dac), C(fd118c77daa8188), C(3aceb7b5e7da6545), C(3c07374d)},
+ {C(f0d6044f6efd7598), C(e044d6ba4369856e), C(91968e4f8c8a1a4c),
+ C(f0f4602c)},
+ {C(3d69e52049879d61), C(76610636ea9f74fe), C(e9bf5602f89310c0),
+ C(3e1ea071)},
+ {C(79da242a16acae31), C(183c5f438e29d40), C(6d351710ae92f3de), C(67580f0c)},
+ {C(461c82656a74fb57), C(d84b491b275aa0f7), C(8f262cb29a6eb8b2),
+ C(4e109454)},
+ {C(53c1a66d0b13003), C(731f060e6fe797fc), C(daa56811791371e3), C(88a474a7)},
+ {C(d3a2efec0f047e9), C(1cabce58853e58ea), C(7a17b2eae3256be4), C(5b5bedd)},
+ {C(43c64d7484f7f9b2), C(5da002b64aafaeb7), C(b576c1e45800a716),
+ C(1aaddfa7)},
+ {C(a7dec6ad81cf7fa1), C(180c1ab708683063), C(95e0fd7008d67cff),
+ C(5be07fd8)},
+ {C(5408a1df99d4aff), C(b9565e588740f6bd), C(abf241813b08006e), C(cbca8606)},
+ {C(a8b27a6bcaeeed4b), C(aec1eeded6a87e39), C(9daf246d6fed8326),
+ C(bde64d01)},
+ {C(9a952a8246fdc269), C(d0dcfcac74ef278c), C(250f7139836f0f1f),
+ C(ee90cf33)},
+ {C(c930841d1d88684f), C(5eb66eb18b7f9672), C(e455d413008a2546),
+ C(4305c3ce)},
+ {C(94dc6971e3cf071a), C(994c7003b73b2b34), C(ea16e85978694e5), C(4b3a1d76)},
+ {C(7fc98006e25cac9), C(77fee0484cda86a7), C(376ec3d447060456), C(a8bb6d80)},
+ {C(bd781c4454103f6), C(612197322f49c931), C(b9cf17fd7e5462d5), C(1f9fa607)},
+ {C(da60e6b14479f9df), C(3bdccf69ece16792), C(18ebf45c4fecfdc9),
+ C(8d0e4ed2)},
+ {C(4ca56a348b6c4d3), C(60618537c3872514), C(2fbb9f0e65871b09), C(1bf31347)},
+ {C(ebd22d4b70946401), C(6863602bf7139017), C(c0b1ac4e11b00666),
+ C(1ae3fc5b)},
+ {C(3cc4693d6cbcb0c), C(501689ea1c70ffa), C(10a4353e9c89e364), C(459c3930)},
+ {C(38908e43f7ba5ef0), C(1ab035d4e7781e76), C(41d133e8c0a68ff7),
+ C(e00c4184)},
+ {C(34983ccc6aa40205), C(21802cad34e72bc4), C(1943e8fb3c17bb8), C(ffc7a781)},
+ {C(86215c45dcac9905), C(ea546afe851cae4b), C(d85b6457e489e374),
+ C(6a125480)},
+ {C(420fc255c38db175), C(d503cd0f3c1208d1), C(d4684e74c825a0bc),
+ C(88a1512b)},
+ {C(1d7a31f5bc8fe2f9), C(4763991092dcf836), C(ed695f55b97416f4),
+ C(549bbbe5)},
+ {C(94129a84c376a26e), C(c245e859dc231933), C(1b8f74fecf917453),
+ C(c133d38c)},
+ {C(1d3a9809dab05c8d), C(adddeb4f71c93e8), C(ef342eb36631edb), C(fcace348)},
+ {C(90fa3ccbd60848da), C(dfa6e0595b569e11), C(e585d067a1f5135d),
+ C(ed7b6f9a)},
+ {C(2dbb4fc71b554514), C(9650e04b86be0f82), C(60f2304fba9274d3),
+ C(6d907dda)},
+ {C(b98bf4274d18374a), C(1b669fd4c7f9a19a), C(b1f5972b88ba2b7a),
+ C(7a4d48d5)},
+ {C(d6781d0b5e18eb68), C(b992913cae09b533), C(58f6021caaee3a40),
+ C(e686f3db)},
+ {C(226651cf18f4884c), C(595052a874f0f51c), C(c9b75162b23bab42), C(cce7c55)},
+ {C(a734fb047d3162d6), C(e523170d240ba3a5), C(125a6972809730e8), C(f58b96b)},
+ {C(c6df6364a24f75a3), C(c294e2c84c4f5df8), C(a88df65c6a89313b),
+ C(1bbf6f60)},
+ {C(d8d1364c1fbcd10), C(2d7cc7f54832deaa), C(4e22c876a7c57625), C(ce5e0cc2)},
+ {C(aae06f9146db885f), C(3598736441e280d9), C(fba339b117083e55),
+ C(584cfd6f)},
+ {C(8955ef07631e3bcc), C(7d70965ea3926f83), C(39aed4134f8b2db6),
+ C(8f9bbc33)},
+ {C(ad611c609cfbe412), C(d3c00b18bf253877), C(90b2172e1f3d0bfd),
+ C(d7640d95)},
+ {C(d5339adc295d5d69), C(b633cc1dcb8b586a), C(ee84184cf5b1aeaf), C(3d12a2b)},
+ {C(40d0aeff521375a8), C(77ba1ad7ecebd506), C(547c6f1a7d9df427),
+ C(aaeafed0)},
+ {C(8b2d54ae1a3df769), C(11e7adaee3216679), C(3483781efc563e03),
+ C(95b9b814)},
+ {C(99c175819b4eae28), C(932e8ff9f7a40043), C(ec78dcab07ca9f7c),
+ C(45fbe66e)},
+ {C(2a418335779b82fc), C(af0295987849a76b), C(c12bc5ff0213f46e),
+ C(b4baa7a8)},
+ {C(3b1fc6a3d279e67d), C(70ea1e49c226396), C(25505adcf104697c), C(83e962fe)},
+ {C(d97eacdf10f1c3c9), C(b54f4654043a36e0), C(b128f6eb09d1234), C(aac3531c)},
+ {C(293a5c1c4e203cd4), C(6b3329f1c130cefe), C(f2e32f8ec76aac91),
+ C(2b1db7cc)},
+ {C(4290e018ffaedde7), C(a14948545418eb5e), C(72d851b202284636),
+ C(cf00cd31)},
+ {C(f919a59cbde8bf2f), C(a56d04203b2dc5a5), C(38b06753ac871e48),
+ C(7d3c43b8)},
+ {C(1d70a3f5521d7fa4), C(fb97b3fdc5891965), C(299d49bbbe3535af),
+ C(cbd5fac6)},
+ {C(6af98d7b656d0d7c), C(d2e99ae96d6b5c0c), C(f63bd1603ef80627),
+ C(76d0fec4)},
+ {C(395b7a8adb96ab75), C(582df7165b20f4a), C(e52bd30e9ff657f9), C(405e3402)},
+ {C(3822dd82c7df012f), C(b9029b40bd9f122b), C(fd25b988468266c4),
+ C(c732c481)},
+ {C(79f7efe4a80b951a), C(dd3a3fddfc6c9c41), C(ab4c812f9e27aa40),
+ C(a8d123c9)},
+ {C(ae6e59f5f055921a), C(e9d9b7bf68e82), C(5ce4e4a5b269cc59), C(1e80ad7d)},
+ {C(8959dbbf07387d36), C(b4658afce48ea35d), C(8f3f82437d8cb8d6),
+ C(52aeb863)},
+ {C(4739613234278a49), C(99ea5bcd340bf663), C(258640912e712b12),
+ C(ef7c0c18)},
+ {C(420e6c926bc54841), C(96dbbf6f4e7c75cd), C(d8d40fa70c3c67bb),
+ C(b6ad4b68)},
+ {C(c8601bab561bc1b7), C(72b26272a0ff869a), C(56fdfc986d6bc3c4),
+ C(c1e46b17)},
+ {C(b2d294931a0e20eb), C(284ffd9a0815bc38), C(1f8a103aac9bbe6), C(57b8df25)},
+ {C(7966f53c37b6c6d7), C(8e6abcfb3aa2b88f), C(7f2e5e0724e5f345),
+ C(e9fa36d6)},
+ {C(be9bb0abd03b7368), C(13bca93a3031be55), C(e864f4f52b55b472),
+ C(8f8daefc)},
+ {C(a08d128c5f1649be), C(a8166c3dbbe19aad), C(cb9f914f829ec62c), C(6e1bb7e)},
+ {C(7c386f0ffe0465ac), C(530419c9d843dbf3), C(7450e3a4f72b8d8c),
+ C(fd0076f0)},
+ {C(bb362094e7ef4f8), C(ff3c2a48966f9725), C(55152803acd4a7fe), C(899b17b6)},
+ {C(cd80dea24321eea4), C(52b4fdc8130c2b15), C(f3ea100b154bfb82),
+ C(e3e84e31)},
+ {C(d599a04125372c3a), C(313136c56a56f363), C(1e993c3677625832),
+ C(eef79b6b)},
+ {C(dbbf541e9dfda0a), C(1479fceb6db4f844), C(31ab576b59062534), C(868e3315)},
+ {C(c2ee3288be4fe2bf), C(c65d2f5ddf32b92), C(af6ecdf121ba5485), C(4639a426)},
+ {C(d86603ced1ed4730), C(f9de718aaada7709), C(db8b9755194c6535),
+ C(f3213646)},
+ {C(915263c671b28809), C(a815378e7ad762fd), C(abec6dc9b669f559),
+ C(17f148e9)},
+ {C(2b67cdd38c307a5e), C(cb1d45bb5c9fe1c), C(800baf2a02ec18ad), C(bfd94880)},
+ {C(2d107419073b9cd0), C(a96db0740cef8f54), C(ec41ee91b3ecdc1b),
+ C(bb1fa7f3)},
+ {C(f3e9487ec0e26dfc), C(1ab1f63224e837fa), C(119983bb5a8125d8), C(88816b1)},
+ {C(1160987c8fe86f7d), C(879e6db1481eb91b), C(d7dcb802bfe6885d),
+ C(5c2faeb3)},
+ {C(eab8112c560b967b), C(97f550b58e89dbae), C(846ed506d304051f),
+ C(51b5fc6f)},
+ {C(1addcf0386d35351), C(b5f436561f8f1484), C(85d38e22181c9bb1),
+ C(33d94752)},
+ {C(d445ba84bf803e09), C(1216c2497038f804), C(2293216ea2237207),
+ C(b0c92948)},
+ {C(37235a096a8be435), C(d9b73130493589c2), C(3b1024f59378d3be),
+ C(c7171590)},
+ {C(763ad6ea2fe1c99d), C(cf7af5368ac1e26b), C(4d5e451b3bb8d3d4),
+ C(240a67fb)},
+ {C(ea627fc84cd1b857), C(85e372494520071f), C(69ec61800845780b),
+ C(e1843cd5)},
+ {C(1f2ffd79f2cdc0c8), C(726a1bc31b337aaa), C(678b7f275ef96434),
+ C(fda1452b)},
+ {C(39a9e146ec4b3210), C(f63f75802a78b1ac), C(e2e22539c94741c3),
+ C(a2cad330)},
+ {C(74cba303e2dd9d6d), C(692699b83289fad1), C(dfb9aa7874678480),
+ C(53467e16)},
+ {C(4cbc2b73a43071e0), C(56c5db4c4ca4e0b7), C(1b275a162f46bd3d),
+ C(da14a8d0)},
+ {C(875638b9715d2221), C(d9ba0615c0c58740), C(616d4be2dfe825aa),
+ C(67333551)},
+ {C(fb686b2782994a8d), C(edee60693756bb48), C(e6bc3cae0ded2ef5),
+ C(a0ebd66e)},
+ {C(ab21d81a911e6723), C(4c31b07354852f59), C(835da384c9384744),
+ C(4b769593)},
+ {C(33d013cc0cd46ecf), C(3de726423aea122c), C(116af51117fe21a9),
+ C(6aa75624)},
+ {C(8ca92c7cd39fae5d), C(317e620e1bf20f1), C(4f0b33bf2194b97f), C(602a3f96)},
+ {C(fdde3b03f018f43e), C(38f932946c78660), C(c84084ce946851ee), C(cd183c4d)},
+ {C(9c8502050e9c9458), C(d6d2a1a69964beb9), C(1675766f480229b5),
+ C(960a4d07)},
+ {C(348176ca2fa2fdd2), C(3a89c514cc360c2d), C(9f90b8afb318d6d0),
+ C(9ae998c4)},
+ {C(4a3d3dfbbaea130b), C(4e221c920f61ed01), C(553fd6cd1304531f),
+ C(74e2179d)},
+ {C(b371f768cdf4edb9), C(bdef2ace6d2de0f0), C(e05b4100f7f1baec),
+ C(ee9bae25)},
+ {C(7a1d2e96934f61f), C(eb1760ae6af7d961), C(887eb0da063005df), C(b66edf10)},
+ {C(8be53d466d4728f2), C(86a5ac8e0d416640), C(984aa464cdb5c8bb),
+ C(d6209737)},
+ {C(829677eb03abf042), C(43cad004b6bc2c0), C(f2f224756803971a), C(b994a88)},
+ {C(754435bae3496fc), C(5707fc006f094dcf), C(8951c86ab19d8e40), C(a05d43c0)},
+ {C(fda9877ea8e3805f), C(31e868b6ffd521b7), C(b08c90681fb6a0fd),
+ C(c79f73a8)},
+ {C(2e36f523ca8f5eb5), C(8b22932f89b27513), C(331cd6ecbfadc1bb),
+ C(a490aff5)},
+ {C(21a378ef76828208), C(a5c13037fa841da2), C(506d22a53fbe9812),
+ C(dfad65b4)},
+ {C(ccdd5600054b16ca), C(f78846e84204cb7b), C(1f9faec82c24eac9), C(1d07dfb)},
+ {C(7854468f4e0cabd0), C(3a3f6b4f098d0692), C(ae2423ec7799d30d),
+ C(416df9a0)},
+ {C(7f88db5346d8f997), C(88eac9aacc653798), C(68a4d0295f8eefa1),
+ C(1f8fb9cc)},
+ {C(bb3fb5fb01d60fcf), C(1b7cc0847a215eb6), C(1246c994437990a1),
+ C(7abf48e3)},
+ {C(2e783e1761acd84d), C(39158042bac975a0), C(1cd21c5a8071188d),
+ C(dea4e3dd)},
+ {C(392058251cf22acc), C(944ec4475ead4620), C(b330a10b5cb94166),
+ C(c6064f22)},
+ {C(adf5c1e5d6419947), C(2a9747bc659d28aa), C(95c5b8cb1f5d62c), C(743bed9c)},
+ {C(6bc1db2c2bee5aba), C(e63b0ed635307398), C(7b2eca111f30dbbc),
+ C(fce254d5)},
+ {C(b00f898229efa508), C(83b7590ad7f6985c), C(2780e70a0592e41d),
+ C(e47ec9d1)},
+ {C(b56eb769ce0d9a8c), C(ce196117bfbcaf04), C(b26c3c3797d66165),
+ C(334a145c)},
+ {C(70c0637675b94150), C(259e1669305b0a15), C(46e1dd9fd387a58d),
+ C(adec1e3c)},
+ {C(74c0b8a6821faafe), C(abac39d7491370e7), C(faf0b2a48a4e6aed),
+ C(f6a9fbf8)},
+ {C(5fb5e48ac7b7fa4f), C(a96170f08f5acbc7), C(bbf5c63d4f52a1e5),
+ C(5398210c)},
+};
+
+void TestUnchanging(const uint64_t* expected, int offset, int len) {
+ EXPECT_EQ(expected[0], CityHash64(data + offset, len));
+ EXPECT_EQ(expected[3], CityHash32(data + offset, len));
+ EXPECT_EQ(expected[1], CityHash64WithSeed(data + offset, len, kSeed0));
+ EXPECT_EQ(expected[2],
+ CityHash64WithSeeds(data + offset, len, kSeed0, kSeed1));
+}
+
+TEST(CityHashTest, Unchanging) {
+ setup();
+ int i = 0;
+ for (; i < kTestSize - 1; i++) {
+ TestUnchanging(testdata[i], i * i, i);
+ }
+ TestUnchanging(testdata[i], 0, kDataSize);
+}
+
+} // namespace hash_internal
+} // inline namespace lts_2018_12_18
+} // namespace absl
diff --git a/absl/hash/internal/hash.cc b/absl/hash/internal/hash.cc
new file mode 100644
index 00000000..3e553625
--- /dev/null
+++ b/absl/hash/internal/hash.cc
@@ -0,0 +1,25 @@
+// 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.
+
+#include "absl/hash/internal/hash.h"
+
+namespace absl {
+inline namespace lts_2018_12_18 {
+namespace hash_internal {
+
+ABSL_CONST_INIT const void* const CityHashState::kSeed = &kSeed;
+
+} // namespace hash_internal
+} // inline namespace lts_2018_12_18
+} // namespace absl
diff --git a/absl/hash/internal/hash.h b/absl/hash/internal/hash.h
new file mode 100644
index 00000000..a51ca954
--- /dev/null
+++ b/absl/hash/internal/hash.h
@@ -0,0 +1,898 @@
+// 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.
+//
+// -----------------------------------------------------------------------------
+// File: hash.h
+// -----------------------------------------------------------------------------
+//
+#ifndef ABSL_HASH_INTERNAL_HASH_H_
+#define ABSL_HASH_INTERNAL_HASH_H_
+
+#include <algorithm>
+#include <array>
+#include <cmath>
+#include <cstring>
+#include <deque>
+#include <forward_list>
+#include <functional>
+#include <iterator>
+#include <limits>
+#include <list>
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include "absl/base/internal/endian.h"
+#include "absl/base/port.h"
+#include "absl/container/fixed_array.h"
+#include "absl/meta/type_traits.h"
+#include "absl/numeric/int128.h"
+#include "absl/strings/string_view.h"
+#include "absl/types/optional.h"
+#include "absl/types/variant.h"
+#include "absl/utility/utility.h"
+#include "absl/hash/internal/city.h"
+
+namespace absl {
+inline namespace lts_2018_12_18 {
+namespace hash_internal {
+
+// HashStateBase
+//
+// A hash state object represents an intermediate state in the computation
+// of an unspecified hash algorithm. `HashStateBase` provides a CRTP style
+// base class for hash state implementations. Developers adding type support
+// for `absl::Hash` should not rely on any parts of the state object other than
+// the following member functions:
+//
+// * HashStateBase::combine()
+// * HashStateBase::combine_contiguous()
+//
+// A derived hash state class of type `H` must provide a static member function
+// with a signature similar to the following:
+//
+// `static H combine_contiguous(H state, const unsigned char*, size_t)`.
+//
+// `HashStateBase` will provide a complete implementations for a hash state
+// object in terms of this method.
+//
+// Example:
+//
+// // Use CRTP to define your derived class.
+// struct MyHashState : HashStateBase<MyHashState> {
+// static H combine_contiguous(H state, const unsigned char*, size_t);
+// using MyHashState::HashStateBase::combine;
+// using MyHashState::HashStateBase::combine_contiguous;
+// };
+template <typename H>
+class HashStateBase {
+ public:
+ // HashStateBase::combine()
+ //
+ // Combines an arbitrary number of values into a hash state, returning the
+ // updated state.
+ //
+ // Each of the value types `T` must be separately hashable by the Abseil
+ // hashing framework.
+ //
+ // NOTE:
+ //
+ // state = H::combine(std::move(state), value1, value2, value3);
+ //
+ // is guaranteed to produce the same hash expansion as:
+ //
+ // state = H::combine(std::move(state), value1);
+ // state = H::combine(std::move(state), value2);
+ // state = H::combine(std::move(state), value3);
+ template <typename T, typename... Ts>
+ static H combine(H state, const T& value, const Ts&... values);
+ static H combine(H state) { return state; }
+
+ // HashStateBase::combine_contiguous()
+ //
+ // Combines a contiguous array of `size` elements into a hash state, returning
+ // the updated state.
+ //
+ // NOTE:
+ //
+ // state = H::combine_contiguous(std::move(state), data, size);
+ //
+ // is NOT guaranteed to produce the same hash expansion as a for-loop (it may
+ // perform internal optimizations). If you need this guarantee, use the
+ // for-loop instead.
+ template <typename T>
+ static H combine_contiguous(H state, const T* data, size_t size);
+};
+
+// is_uniquely_represented
+//
+// `is_uniquely_represented<T>` is a trait class that indicates whether `T`
+// is uniquely represented.
+//
+// A type is "uniquely represented" if two equal values of that type are
+// guaranteed to have the same bytes in their underlying storage. In other
+// words, if `a == b`, then `memcmp(&a, &b, sizeof(T))` is guaranteed to be
+// zero. This property cannot be detected automatically, so this trait is false
+// by default, but can be specialized by types that wish to assert that they are
+// uniquely represented. This makes them eligible for certain optimizations.
+//
+// If you have any doubt whatsoever, do not specialize this template.
+// The default is completely safe, and merely disables some optimizations
+// that will not matter for most types. Specializing this template,
+// on the other hand, can be very hazardous.
+//
+// To be uniquely represented, a type must not have multiple ways of
+// representing the same value; for example, float and double are not
+// uniquely represented, because they have distinct representations for
+// +0 and -0. Furthermore, the type's byte representation must consist
+// solely of user-controlled data, with no padding bits and no compiler-
+// controlled data such as vptrs or sanitizer metadata. This is usually
+// very difficult to guarantee, because in most cases the compiler can
+// insert data and padding bits at its own discretion.
+//
+// If you specialize this template for a type `T`, you must do so in the file
+// that defines that type (or in this file). If you define that specialization
+// anywhere else, `is_uniquely_represented<T>` could have different meanings
+// in different places.
+//
+// The Enable parameter is meaningless; it is provided as a convenience,
+// to support certain SFINAE techniques when defining specializations.
+template <typename T, typename Enable = void>
+struct is_uniquely_represented : std::false_type {};
+
+// is_uniquely_represented<unsigned char>
+//
+// unsigned char is a synonym for "byte", so it is guaranteed to be
+// uniquely represented.
+template <>
+struct is_uniquely_represented<unsigned char> : std::true_type {};
+
+// is_uniquely_represented for non-standard integral types
+//
+// Integral types other than bool should be uniquely represented on any
+// platform that this will plausibly be ported to.
+template <typename Integral>
+struct is_uniquely_represented<
+ Integral, typename std::enable_if<std::is_integral<Integral>::value>::type>
+ : std::true_type {};
+
+// is_uniquely_represented<bool>
+//
+//
+template <>
+struct is_uniquely_represented<bool> : std::false_type {};
+
+// hash_bytes()
+//
+// Convenience function that combines `hash_state` with the byte representation
+// of `value`.
+template <typename H, typename T>
+H hash_bytes(H hash_state, const T& value) {
+ const unsigned char* start = reinterpret_cast<const unsigned char*>(&value);
+ return H::combine_contiguous(std::move(hash_state), start, sizeof(value));
+}
+
+// -----------------------------------------------------------------------------
+// AbslHashValue for Basic Types
+// -----------------------------------------------------------------------------
+
+// Note: Default `AbslHashValue` implementations live in `hash_internal`. This
+// allows us to block lexical scope lookup when doing an unqualified call to
+// `AbslHashValue` below. User-defined implementations of `AbslHashValue` can
+// only be found via ADL.
+
+// AbslHashValue() for hashing bool values
+//
+// We use SFINAE to ensure that this overload only accepts bool, not types that
+// are convertible to bool.
+template <typename H, typename B>
+typename std::enable_if<std::is_same<B, bool>::value, H>::type AbslHashValue(
+ H hash_state, B value) {
+ return H::combine(std::move(hash_state),
+ static_cast<unsigned char>(value ? 1 : 0));
+}
+
+// AbslHashValue() for hashing enum values
+template <typename H, typename Enum>
+typename std::enable_if<std::is_enum<Enum>::value, H>::type AbslHashValue(
+ H hash_state, Enum e) {
+ // In practice, we could almost certainly just invoke hash_bytes directly,
+ // but it's possible that a sanitizer might one day want to
+ // store data in the unused bits of an enum. To avoid that risk, we
+ // convert to the underlying type before hashing. Hopefully this will get
+ // optimized away; if not, we can reopen discussion with c-toolchain-team.
+ return H::combine(std::move(hash_state),
+ static_cast<typename std::underlying_type<Enum>::type>(e));
+}
+// AbslHashValue() for hashing floating-point values
+template <typename H, typename Float>
+typename std::enable_if<std::is_floating_point<Float>::value, H>::type
+AbslHashValue(H hash_state, Float value) {
+ return hash_internal::hash_bytes(std::move(hash_state),
+ value == 0 ? 0 : value);
+}
+
+// Long double has the property that it might have extra unused bytes in it.
+// For example, in x86 sizeof(long double)==16 but it only really uses 80-bits
+// of it. This means we can't use hash_bytes on a long double and have to
+// convert it to something else first.
+template <typename H>
+H AbslHashValue(H hash_state, long double value) {
+ const int category = std::fpclassify(value);
+ switch (category) {
+ case FP_INFINITE:
+ // Add the sign bit to differentiate between +Inf and -Inf
+ hash_state = H::combine(std::move(hash_state), std::signbit(value));
+ break;
+
+ case FP_NAN:
+ case FP_ZERO:
+ default:
+ // Category is enough for these.
+ break;
+
+ case FP_NORMAL:
+ case FP_SUBNORMAL:
+ // We can't convert `value` directly to double because this would have
+ // undefined behavior if the value is out of range.
+ // std::frexp gives us a value in the range (-1, -.5] or [.5, 1) that is
+ // guaranteed to be in range for `double`. The truncation is
+ // implementation defined, but that works as long as it is deterministic.
+ int exp;
+ auto mantissa = static_cast<double>(std::frexp(value, &exp));
+ hash_state = H::combine(std::move(hash_state), mantissa, exp);
+ }
+
+ return H::combine(std::move(hash_state), category);
+}
+
+// AbslHashValue() for hashing pointers
+template <typename H, typename T>
+H AbslHashValue(H hash_state, T* ptr) {
+ return hash_internal::hash_bytes(std::move(hash_state), ptr);
+}
+
+// AbslHashValue() for hashing nullptr_t
+template <typename H>
+H AbslHashValue(H hash_state, std::nullptr_t) {
+ return H::combine(std::move(hash_state), static_cast<void*>(nullptr));
+}
+
+// -----------------------------------------------------------------------------
+// AbslHashValue for Composite Types
+// -----------------------------------------------------------------------------
+
+// is_hashable()
+//
+// Trait class which returns true if T is hashable by the absl::Hash framework.
+// Used for the AbslHashValue implementations for composite types below.
+template <typename T>
+struct is_hashable;
+
+// AbslHashValue() for hashing pairs
+template <typename H, typename T1, typename T2>
+typename std::enable_if<is_hashable<T1>::value && is_hashable<T2>::value,
+ H>::type
+AbslHashValue(H hash_state, const std::pair<T1, T2>& p) {
+ return H::combine(std::move(hash_state), p.first, p.second);
+}
+
+// hash_tuple()
+//
+// Helper function for hashing a tuple. The third argument should
+// be an index_sequence running from 0 to tuple_size<Tuple> - 1.
+template <typename H, typename Tuple, size_t... Is>
+H hash_tuple(H hash_state, const Tuple& t, absl::index_sequence<Is...>) {
+ return H::combine(std::move(hash_state), std::get<Is>(t)...);
+}
+
+// AbslHashValue for hashing tuples
+template <typename H, typename... Ts>
+#if defined(_MSC_VER)
+// This SFINAE gets MSVC confused under some conditions. Let's just disable it
+// for now.
+H
+#else // _MSC_VER
+typename std::enable_if<absl::conjunction<is_hashable<Ts>...>::value, H>::type
+#endif // _MSC_VER
+AbslHashValue(H hash_state, const std::tuple<Ts...>& t) {
+ return hash_internal::hash_tuple(std::move(hash_state), t,
+ absl::make_index_sequence<sizeof...(Ts)>());
+}
+
+// -----------------------------------------------------------------------------
+// AbslHashValue for Pointers
+// -----------------------------------------------------------------------------
+
+// AbslHashValue for hashing unique_ptr
+template <typename H, typename T, typename D>
+H AbslHashValue(H hash_state, const std::unique_ptr<T, D>& ptr) {
+ return H::combine(std::move(hash_state), ptr.get());
+}
+
+// AbslHashValue for hashing shared_ptr
+template <typename H, typename T>
+H AbslHashValue(H hash_state, const std::shared_ptr<T>& ptr) {
+ return H::combine(std::move(hash_state), ptr.get());
+}
+
+// -----------------------------------------------------------------------------
+// AbslHashValue for String-Like Types
+// -----------------------------------------------------------------------------
+
+// AbslHashValue for hashing strings
+//
+// All the string-like types supported here provide the same hash expansion for
+// the same character sequence. These types are:
+//
+// - `std::string` (and std::basic_string<char, std::char_traits<char>, A> for
+// any allocator A)
+// - `absl::string_view` and `std::string_view`
+//
+// For simplicity, we currently support only `char` strings. This support may
+// be broadened, if necessary, but with some caution - this overload would
+// misbehave in cases where the traits' `eq()` member isn't equivalent to `==`
+// on the underlying character type.
+template <typename H>
+H AbslHashValue(H hash_state, absl::string_view str) {
+ return H::combine(
+ H::combine_contiguous(std::move(hash_state), str.data(), str.size()),
+ str.size());
+}
+
+// -----------------------------------------------------------------------------
+// AbslHashValue for Sequence Containers
+// -----------------------------------------------------------------------------
+
+// AbslHashValue for hashing std::array
+template <typename H, typename T, size_t N>
+typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
+ H hash_state, const std::array<T, N>& array) {
+ return H::combine_contiguous(std::move(hash_state), array.data(),
+ array.size());
+}
+
+// AbslHashValue for hashing std::deque
+template <typename H, typename T, typename Allocator>
+typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
+ H hash_state, const std::deque<T, Allocator>& deque) {
+ // TODO(gromer): investigate a more efficient implementation taking
+ // advantage of the chunk structure.
+ for (const auto& t : deque) {
+ hash_state = H::combine(std::move(hash_state), t);
+ }
+ return H::combine(std::move(hash_state), deque.size());
+}
+
+// AbslHashValue for hashing std::forward_list
+template <typename H, typename T, typename Allocator>
+typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
+ H hash_state, const std::forward_list<T, Allocator>& list) {
+ size_t size = 0;
+ for (const T& t : list) {
+ hash_state = H::combine(std::move(hash_state), t);
+ ++size;
+ }
+ return H::combine(std::move(hash_state), size);
+}
+
+// AbslHashValue for hashing std::list
+template <typename H, typename T, typename Allocator>
+typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
+ H hash_state, const std::list<T, Allocator>& list) {
+ for (const auto& t : list) {
+ hash_state = H::combine(std::move(hash_state), t);
+ }
+ return H::combine(std::move(hash_state), list.size());
+}
+
+// AbslHashValue for hashing std::vector
+//
+// Do not use this for vector<bool>. It does not have a .data(), and a fallback
+// for std::hash<> is most likely faster.
+template <typename H, typename T, typename Allocator>
+typename std::enable_if<is_hashable<T>::value && !std::is_same<T, bool>::value,
+ H>::type
+AbslHashValue(H hash_state, const std::vector<T, Allocator>& vector) {
+ return H::combine(H::combine_contiguous(std::move(hash_state), vector.data(),
+ vector.size()),
+ vector.size());
+}
+
+// -----------------------------------------------------------------------------
+// AbslHashValue for Ordered Associative Containers
+// -----------------------------------------------------------------------------
+
+// AbslHashValue for hashing std::map
+template <typename H, typename Key, typename T, typename Compare,
+ typename Allocator>
+typename std::enable_if<is_hashable<Key>::value && is_hashable<T>::value,
+ H>::type
+AbslHashValue(H hash_state, const std::map<Key, T, Compare, Allocator>& map) {
+ for (const auto& t : map) {
+ hash_state = H::combine(std::move(hash_state), t);
+ }
+ return H::combine(std::move(hash_state), map.size());
+}
+
+// AbslHashValue for hashing std::multimap
+template <typename H, typename Key, typename T, typename Compare,
+ typename Allocator>
+typename std::enable_if<is_hashable<Key>::value && is_hashable<T>::value,
+ H>::type
+AbslHashValue(H hash_state,
+ const std::multimap<Key, T, Compare, Allocator>& map) {
+ for (const auto& t : map) {
+ hash_state = H::combine(std::move(hash_state), t);
+ }
+ return H::combine(std::move(hash_state), map.size());
+}
+
+// AbslHashValue for hashing std::set
+template <typename H, typename Key, typename Compare, typename Allocator>
+typename std::enable_if<is_hashable<Key>::value, H>::type AbslHashValue(
+ H hash_state, const std::set<Key, Compare, Allocator>& set) {
+ for (const auto& t : set) {
+ hash_state = H::combine(std::move(hash_state), t);
+ }
+ return H::combine(std::move(hash_state), set.size());
+}
+
+// AbslHashValue for hashing std::multiset
+template <typename H, typename Key, typename Compare, typename Allocator>
+typename std::enable_if<is_hashable<Key>::value, H>::type AbslHashValue(
+ H hash_state, const std::multiset<Key, Compare, Allocator>& set) {
+ for (const auto& t : set) {
+ hash_state = H::combine(std::move(hash_state), t);
+ }
+ return H::combine(std::move(hash_state), set.size());
+}
+
+// -----------------------------------------------------------------------------
+// AbslHashValue for Wrapper Types
+// -----------------------------------------------------------------------------
+
+// AbslHashValue for hashing absl::optional
+template <typename H, typename T>
+typename std::enable_if<is_hashable<T>::value, H>::type AbslHashValue(
+ H hash_state, const absl::optional<T>& opt) {
+ if (opt) hash_state = H::combine(std::move(hash_state), *opt);
+ return H::combine(std::move(hash_state), opt.has_value());
+}
+
+// VariantVisitor
+template <typename H>
+struct VariantVisitor {
+ H&& hash_state;
+ template <typename T>
+ H operator()(const T& t) const {
+ return H::combine(std::move(hash_state), t);
+ }
+};
+
+// AbslHashValue for hashing absl::variant
+template <typename H, typename... T>
+typename std::enable_if<conjunction<is_hashable<T>...>::value, H>::type
+AbslHashValue(H hash_state, const absl::variant<T...>& v) {
+ if (!v.valueless_by_exception()) {
+ hash_state = absl::visit(VariantVisitor<H>{std::move(hash_state)}, v);
+ }
+ return H::combine(std::move(hash_state), v.index());
+}
+
+// -----------------------------------------------------------------------------
+// AbslHashValue for Other Types
+// -----------------------------------------------------------------------------
+
+// AbslHashValue for hashing std::bitset is not defined, for the same reason as
+// for vector<bool> (see std::vector above): It does not expose the raw bytes,
+// and a fallback to std::hash<> is most likely faster.
+
+// -----------------------------------------------------------------------------
+
+// hash_range_or_bytes()
+//
+// Mixes all values in the range [data, data+size) into the hash state.
+// This overload accepts only uniquely-represented types, and hashes them by
+// hashing the entire range of bytes.
+template <typename H, typename T>
+typename std::enable_if<is_uniquely_represented<T>::value, H>::type
+hash_range_or_bytes(H hash_state, const T* data, size_t size) {
+ const auto* bytes = reinterpret_cast<const unsigned char*>(data);
+ return H::combine_contiguous(std::move(hash_state), bytes, sizeof(T) * size);
+}
+
+// hash_range_or_bytes()
+template <typename H, typename T>
+typename std::enable_if<!is_uniquely_represented<T>::value, H>::type
+hash_range_or_bytes(H hash_state, const T* data, size_t size) {
+ for (const auto end = data + size; data < end; ++data) {
+ hash_state = H::combine(std::move(hash_state), *data);
+ }
+ return hash_state;
+}
+
+// InvokeHashTag
+//
+// InvokeHash(H, const T&) invokes the appropriate hash implementation for a
+// hasher of type `H` and a value of type `T`. If `T` is not hashable, there
+// will be no matching overload of InvokeHash().
+// Note: Some platforms (eg MSVC) do not support the detect idiom on
+// std::hash. In those platforms the last fallback will be std::hash and
+// InvokeHash() will always have a valid overload even if std::hash<T> is not
+// valid.
+//
+// We try the following options in order:
+// * If is_uniquely_represented, hash bytes directly.
+// * ADL AbslHashValue(H, const T&) call.
+// * std::hash<T>
+
+// In MSVC we can't probe std::hash or stdext::hash because it triggers a
+// static_assert instead of failing substitution.
+#if defined(_MSC_VER)
+#define ABSL_HASH_INTERNAL_CAN_POISON_ 0
+#else // _MSC_VER
+#define ABSL_HASH_INTERNAL_CAN_POISON_ 1
+#endif // _MSC_VER
+
+#if defined(ABSL_INTERNAL_LEGACY_HASH_NAMESPACE) && \
+ ABSL_HASH_INTERNAL_CAN_POISON_
+#define ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_ 1
+#else
+#define ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_ 0
+#endif
+
+enum class InvokeHashTag {
+ kUniquelyRepresented,
+ kHashValue,
+#if ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
+ kLegacyHash,
+#endif // ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
+ kStdHash,
+ kNone
+};
+
+// HashSelect
+//
+// Type trait to select the appropriate hash implementation to use.
+// HashSelect<T>::value is an instance of InvokeHashTag that indicates the best
+// available hashing mechanism.
+// See `Note` above about MSVC.
+template <typename T>
+struct HashSelect {
+ private:
+ struct State : HashStateBase<State> {
+ static State combine_contiguous(State hash_state, const unsigned char*,
+ size_t);
+ using State::HashStateBase::combine_contiguous;
+ };
+
+ // `Probe<V, Tag>::value` evaluates to `V<T>::value` if it is a valid
+ // expression, and `false` otherwise.
+ // `Probe<V, Tag>::tag` always evaluates to `Tag`.
+ template <template <typename> class V, InvokeHashTag Tag>
+ struct Probe {
+ private:
+ template <typename U, typename std::enable_if<V<U>::value, int>::type = 0>
+ static std::true_type Test(int);
+ template <typename U>
+ static std::false_type Test(char);
+
+ public:
+ static constexpr InvokeHashTag kTag = Tag;
+ static constexpr bool value = decltype(
+ Test<absl::remove_const_t<absl::remove_reference_t<T>>>(0))::value;
+ };
+
+ template <typename U>
+ using ProbeUniquelyRepresented = is_uniquely_represented<U>;
+
+ template <typename U>
+ using ProbeHashValue =
+ std::is_same<State, decltype(AbslHashValue(std::declval<State>(),
+ std::declval<const U&>()))>;
+
+#if ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
+ template <typename U>
+ using ProbeLegacyHash =
+ std::is_convertible<decltype(ABSL_INTERNAL_LEGACY_HASH_NAMESPACE::hash<
+ U>()(std::declval<const U&>())),
+ size_t>;
+#endif // ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
+
+ template <typename U>
+ using ProbeStdHash =
+#if ABSL_HASH_INTERNAL_CAN_POISON_
+ std::is_convertible<decltype(std::hash<U>()(std::declval<const U&>())),
+ size_t>;
+#else // ABSL_HASH_INTERNAL_CAN_POISON_
+ std::true_type;
+#endif // ABSL_HASH_INTERNAL_CAN_POISON_
+
+ template <typename U>
+ using ProbeNone = std::true_type;
+
+ public:
+ // Probe each implementation in order.
+ // disjunction provides short circuting wrt instantiation.
+ static constexpr InvokeHashTag value = absl::disjunction<
+ Probe<ProbeUniquelyRepresented, InvokeHashTag::kUniquelyRepresented>,
+ Probe<ProbeHashValue, InvokeHashTag::kHashValue>,
+#if ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
+ Probe<ProbeLegacyHash, InvokeHashTag::kLegacyHash>,
+#endif // ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
+ Probe<ProbeStdHash, InvokeHashTag::kStdHash>,
+ Probe<ProbeNone, InvokeHashTag::kNone>>::kTag;
+};
+
+template <typename T>
+struct is_hashable : std::integral_constant<bool, HashSelect<T>::value !=
+ InvokeHashTag::kNone> {};
+
+template <typename H, typename T>
+absl::enable_if_t<HashSelect<T>::value == InvokeHashTag::kUniquelyRepresented,
+ H>
+InvokeHash(H state, const T& value) {
+ return hash_internal::hash_bytes(std::move(state), value);
+}
+
+template <typename H, typename T>
+absl::enable_if_t<HashSelect<T>::value == InvokeHashTag::kHashValue, H>
+InvokeHash(H state, const T& value) {
+ return AbslHashValue(std::move(state), value);
+}
+
+#if ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
+template <typename H, typename T>
+absl::enable_if_t<HashSelect<T>::value == InvokeHashTag::kLegacyHash, H>
+InvokeHash(H state, const T& value) {
+ return hash_internal::hash_bytes(
+ std::move(state), ABSL_INTERNAL_LEGACY_HASH_NAMESPACE::hash<T>{}(value));
+}
+#endif // ABSL_HASH_INTERNAL_SUPPORT_LEGACY_HASH_
+
+template <typename H, typename T>
+absl::enable_if_t<HashSelect<T>::value == InvokeHashTag::kStdHash, H>
+InvokeHash(H state, const T& value) {
+ return hash_internal::hash_bytes(std::move(state), std::hash<T>{}(value));
+}
+
+// CityHashState
+class CityHashState : public HashStateBase<CityHashState> {
+ // absl::uint128 is not an alias or a thin wrapper around the intrinsic.
+ // We use the intrinsic when available to improve performance.
+#ifdef ABSL_HAVE_INTRINSIC_INT128
+ using uint128 = __uint128_t;
+#else // ABSL_HAVE_INTRINSIC_INT128
+ using uint128 = absl::uint128;
+#endif // ABSL_HAVE_INTRINSIC_INT128
+
+ static constexpr uint64_t kMul =
+ sizeof(size_t) == 4 ? uint64_t{0xcc9e2d51} : uint64_t{0x9ddfea08eb382d69};
+
+ template <typename T>
+ using IntegralFastPath =
+ conjunction<std::is_integral<T>, is_uniquely_represented<T>>;
+
+ public:
+ // Move only
+ CityHashState(CityHashState&&) = default;
+ CityHashState& operator=(CityHashState&&) = default;
+
+ // CityHashState::combine_contiguous()
+ //
+ // Fundamental base case for hash recursion: mixes the given range of bytes
+ // into the hash state.
+ static CityHashState combine_contiguous(CityHashState hash_state,
+ const unsigned char* first,
+ size_t size) {
+ return CityHashState(
+ CombineContiguousImpl(hash_state.state_, first, size,
+ std::integral_constant<int, sizeof(size_t)>{}));
+ }
+ using CityHashState::HashStateBase::combine_contiguous;
+
+ // CityHashState::hash()
+ //
+ // For performance reasons in non-opt mode, we specialize this for
+ // integral types.
+ // Otherwise we would be instantiating and calling dozens of functions for
+ // something that is just one multiplication and a couple xor's.
+ // The result should be the same as running the whole algorithm, but faster.
+ template <typename T, absl::enable_if_t<IntegralFastPath<T>::value, int> = 0>
+ static size_t hash(T value) {
+ return static_cast<size_t>(Mix(Seed(), static_cast<uint64_t>(value)));
+ }
+
+ // Overload of CityHashState::hash()
+ template <typename T, absl::enable_if_t<!IntegralFastPath<T>::value, int> = 0>
+ static size_t hash(const T& value) {
+ return static_cast<size_t>(combine(CityHashState{}, value).state_);
+ }
+
+ private:
+ // Invoked only once for a given argument; that plus the fact that this is
+ // move-only ensures that there is only one non-moved-from object.
+ CityHashState() : state_(Seed()) {}
+
+ // Workaround for MSVC bug.
+ // We make the type copyable to fix the calling convention, even though we
+ // never actually copy it. Keep it private to not affect the public API of the
+ // type.
+ CityHashState(const CityHashState&) = default;
+
+ explicit CityHashState(uint64_t state) : state_(state) {}
+
+ // Implementation of the base case for combine_contiguous where we actually
+ // mix the bytes into the state.
+ // Dispatch to different implementations of the combine_contiguous depending
+ // on the value of `sizeof(size_t)`.
+ static uint64_t CombineContiguousImpl(uint64_t state,
+ const unsigned char* first, size_t len,
+ std::integral_constant<int, 4>
+ /* sizeof_size_t */);
+ static uint64_t CombineContiguousImpl(uint64_t state,
+ const unsigned char* first, size_t len,
+ std::integral_constant<int, 8>
+ /* sizeof_size_t*/);
+
+ // Reads 9 to 16 bytes from p.
+ // The first 8 bytes are in .first, the rest (zero padded) bytes are in
+ // .second.
+ static std::pair<uint64_t, uint64_t> Read9To16(const unsigned char* p,
+ size_t len) {
+ uint64_t high = little_endian::Load64(p + len - 8);
+ return {little_endian::Load64(p), high >> (128 - len * 8)};
+ }
+
+ // Reads 4 to 8 bytes from p. Zero pads to fill uint64_t.
+ static uint64_t Read4To8(const unsigned char* p, size_t len) {
+ return (static_cast<uint64_t>(little_endian::Load32(p + len - 4))
+ << (len - 4) * 8) |
+ little_endian::Load32(p);
+ }
+
+ // Reads 1 to 3 bytes from p. Zero pads to fill uint32_t.
+ static uint32_t Read1To3(const unsigned char* p, size_t len) {
+ return static_cast<uint32_t>((p[0]) | //
+ (p[len / 2] << (len / 2 * 8)) | //
+ (p[len - 1] << ((len - 1) * 8)));
+ }
+
+ ABSL_ATTRIBUTE_ALWAYS_INLINE static uint64_t Mix(uint64_t state, uint64_t v) {
+ using MultType =
+ absl::conditional_t<sizeof(size_t) == 4, uint64_t, uint128>;
+ // We do the addition in 64-bit space to make sure the 128-bit
+ // multiplication is fast. If we were to do it as MultType the compiler has
+ // to assume that the high word is non-zero and needs to perform 2
+ // multiplications instead of one.
+ MultType m = state + v;
+ m *= kMul;
+ return static_cast<uint64_t>(m ^ (m >> (sizeof(m) * 8 / 2)));
+ }
+
+ // Seed()
+ //
+ // A non-deterministic seed.
+ //
+ // The current purpose of this seed is to generate non-deterministic results
+ // and prevent having users depend on the particular hash values.
+ // It is not meant as a security feature right now, but it leaves the door
+ // open to upgrade it to a true per-process random seed. A true random seed
+ // costs more and we don't need to pay for that right now.
+ //
+ // On platforms with ASLR, we take advantage of it to make a per-process
+ // random value.
+ // See https://en.wikipedia.org/wiki/Address_space_layout_randomization
+ //
+ // On other platforms this is still going to be non-deterministic but most
+ // probably per-build and not per-process.
+ ABSL_ATTRIBUTE_ALWAYS_INLINE static uint64_t Seed() {
+ return static_cast<uint64_t>(reinterpret_cast<uintptr_t>(kSeed));
+ }
+ static const void* const kSeed;
+
+ uint64_t state_;
+};
+
+// CityHashState::CombineContiguousImpl()
+inline uint64_t CityHashState::CombineContiguousImpl(
+ uint64_t state, const unsigned char* first, size_t len,
+ std::integral_constant<int, 4> /* sizeof_size_t */) {
+ // For large values we use CityHash, for small ones we just use a
+ // multiplicative hash.
+ uint64_t v;
+ if (len > 8) {
+ v = absl::hash_internal::CityHash32(reinterpret_cast<const char*>(first), len);
+ } else if (len >= 4) {
+ v = Read4To8(first, len);
+ } else if (len > 0) {
+ v = Read1To3(first, len);
+ } else {
+ // Empty ranges have no effect.
+ return state;
+ }
+ return Mix(state, v);
+}
+
+// Overload of CityHashState::CombineContiguousImpl()
+inline uint64_t CityHashState::CombineContiguousImpl(
+ uint64_t state, const unsigned char* first, size_t len,
+ std::integral_constant<int, 8> /* sizeof_size_t */) {
+ // For large values we use CityHash, for small ones we just use a
+ // multiplicative hash.
+ uint64_t v;
+ if (len > 16) {
+ v = absl::hash_internal::CityHash64(reinterpret_cast<const char*>(first), len);
+ } else if (len > 8) {
+ auto p = Read9To16(first, len);
+ state = Mix(state, p.first);
+ v = p.second;
+ } else if (len >= 4) {
+ v = Read4To8(first, len);
+ } else if (len > 0) {
+ v = Read1To3(first, len);
+ } else {
+ // Empty ranges have no effect.
+ return state;
+ }
+ return Mix(state, v);
+}
+
+
+struct AggregateBarrier {};
+
+// HashImpl
+
+// Add a private base class to make sure this type is not an aggregate.
+// Aggregates can be aggregate initialized even if the default constructor is
+// deleted.
+struct PoisonedHash : private AggregateBarrier {
+ PoisonedHash() = delete;
+ PoisonedHash(const PoisonedHash&) = delete;
+ PoisonedHash& operator=(const PoisonedHash&) = delete;
+};
+
+template <typename T>
+struct HashImpl {
+ size_t operator()(const T& value) const { return CityHashState::hash(value); }
+};
+
+template <typename T>
+struct Hash
+ : absl::conditional_t<is_hashable<T>::value, HashImpl<T>, PoisonedHash> {};
+
+template <typename H>
+template <typename T, typename... Ts>
+H HashStateBase<H>::combine(H state, const T& value, const Ts&... values) {
+ return H::combine(hash_internal::InvokeHash(std::move(state), value),
+ values...);
+}
+
+// HashStateBase::combine_contiguous()
+template <typename H>
+template <typename T>
+H HashStateBase<H>::combine_contiguous(H state, const T* data, size_t size) {
+ return hash_internal::hash_range_or_bytes(std::move(state), data, size);
+}
+} // namespace hash_internal
+} // inline namespace lts_2018_12_18
+} // namespace absl
+
+#endif // ABSL_HASH_INTERNAL_HASH_H_
diff --git a/absl/hash/internal/print_hash_of.cc b/absl/hash/internal/print_hash_of.cc
new file mode 100644
index 00000000..b6df31cc
--- /dev/null
+++ b/absl/hash/internal/print_hash_of.cc
@@ -0,0 +1,23 @@
+// 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.
+
+#include <cstdlib>
+
+#include "absl/hash/hash.h"
+
+// Prints the hash of argv[1].
+int main(int argc, char** argv) {
+ if (argc < 2) return 1;
+ printf("%zu\n", absl::Hash<int>{}(std::atoi(argv[1]))); // NOLINT
+}
diff --git a/absl/hash/internal/spy_hash_state.h b/absl/hash/internal/spy_hash_state.h
new file mode 100644
index 00000000..1886d2ef
--- /dev/null
+++ b/absl/hash/internal/spy_hash_state.h
@@ -0,0 +1,220 @@
+// 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.
+
+#ifndef ABSL_HASH_INTERNAL_SPY_HASH_STATE_H_
+#define ABSL_HASH_INTERNAL_SPY_HASH_STATE_H_
+
+#include <ostream>
+#include <string>
+#include <vector>
+
+#include "absl/hash/hash.h"
+#include "absl/strings/match.h"
+#include "absl/strings/str_format.h"
+#include "absl/strings/str_join.h"
+
+namespace absl {
+inline namespace lts_2018_12_18 {
+namespace hash_internal {
+
+// SpyHashState is an implementation of the HashState API that simply
+// accumulates all input bytes in an internal buffer. This makes it useful
+// for testing AbslHashValue overloads (so long as they are templated on the
+// HashState parameter), since it can report the exact hash representation
+// that the AbslHashValue overload produces.
+//
+// Sample usage:
+// EXPECT_EQ(SpyHashState::combine(SpyHashState(), foo),
+// SpyHashState::combine(SpyHashState(), bar));
+template <typename T>
+class SpyHashStateImpl : public HashStateBase<SpyHashStateImpl<T>> {
+ public:
+ SpyHashStateImpl()
+ : error_(std::make_shared<absl::optional<std::string>>()) {
+ static_assert(std::is_void<T>::value, "");
+ }
+
+ // Move-only
+ SpyHashStateImpl(const SpyHashStateImpl&) = delete;
+ SpyHashStateImpl& operator=(const SpyHashStateImpl&) = delete;
+
+ SpyHashStateImpl(SpyHashStateImpl&& other) noexcept {
+ *this = std::move(other);
+ }
+
+ SpyHashStateImpl& operator=(SpyHashStateImpl&& other) noexcept {
+ hash_representation_ = std::move(other.hash_representation_);
+ error_ = other.error_;
+ moved_from_ = other.moved_from_;
+ other.moved_from_ = true;
+ return *this;
+ }
+
+ template <typename U>
+ SpyHashStateImpl(SpyHashStateImpl<U>&& other) { // NOLINT
+ hash_representation_ = std::move(other.hash_representation_);
+ error_ = other.error_;
+ moved_from_ = other.moved_from_;
+ other.moved_from_ = true;
+ }
+
+ template <typename A, typename... Args>
+ static SpyHashStateImpl combine(SpyHashStateImpl s, const A& a,
+ const Args&... args) {
+ // Pass an instance of SpyHashStateImpl<A> when trying to combine `A`. This
+ // allows us to test that the user only uses this instance for combine calls
+ // and does not call AbslHashValue directly.
+ // See AbslHashValue implementation at the bottom.
+ s = SpyHashStateImpl<A>::HashStateBase::combine(std::move(s), a);
+ return SpyHashStateImpl::combine(std::move(s), args...);
+ }
+ static SpyHashStateImpl combine(SpyHashStateImpl s) {
+ if (direct_absl_hash_value_error_) {
+ *s.error_ = "AbslHashValue should not be invoked directly.";
+ } else if (s.moved_from_) {
+ *s.error_ = "Used moved-from instance of the hash state object.";
+ }
+ return s;
+ }
+
+ static void SetDirectAbslHashValueError() {
+ direct_absl_hash_value_error_ = true;
+ }
+
+ // Two SpyHashStateImpl objects are equal if they hold equal hash
+ // representations.
+ friend bool operator==(const SpyHashStateImpl& lhs,
+ const SpyHashStateImpl& rhs) {
+ return lhs.hash_representation_ == rhs.hash_representation_;
+ }
+
+ friend bool operator!=(const SpyHashStateImpl& lhs,
+ const SpyHashStateImpl& rhs) {
+ return !(lhs == rhs);
+ }
+
+ enum class CompareResult {
+ kEqual,
+ kASuffixB,
+ kBSuffixA,
+ kUnequal,
+ };
+
+ static CompareResult Compare(const SpyHashStateImpl& a,
+ const SpyHashStateImpl& b) {
+ const std::string a_flat = absl::StrJoin(a.hash_representation_, "");
+ const std::string b_flat = absl::StrJoin(b.hash_representation_, "");
+ if (a_flat == b_flat) return CompareResult::kEqual;
+ if (absl::EndsWith(a_flat, b_flat)) return CompareResult::kBSuffixA;
+ if (absl::EndsWith(b_flat, a_flat)) return CompareResult::kASuffixB;
+ return CompareResult::kUnequal;
+ }
+
+ // operator<< prints the hash representation as a hex and ASCII dump, to
+ // facilitate debugging.
+ friend std::ostream& operator<<(std::ostream& out,
+ const SpyHashStateImpl& hash_state) {
+ out << "[\n";
+ for (auto& s : hash_state.hash_representation_) {
+ size_t offset = 0;
+ for (char c : s) {
+ if (offset % 16 == 0) {
+ out << absl::StreamFormat("\n0x%04x: ", offset);
+ }
+ if (offset % 2 == 0) {
+ out << " ";
+ }
+ out << absl::StreamFormat("%02x", c);
+ ++offset;
+ }
+ out << "\n";
+ }
+ return out << "]";
+ }
+
+ // The base case of the combine recursion, which writes raw bytes into the
+ // internal buffer.
+ static SpyHashStateImpl combine_contiguous(SpyHashStateImpl hash_state,
+ const unsigned char* begin,
+ size_t size) {
+ hash_state.hash_representation_.emplace_back(
+ reinterpret_cast<const char*>(begin), size);
+ return hash_state;
+ }
+
+ using SpyHashStateImpl::HashStateBase::combine_contiguous;
+
+ absl::optional<std::string> error() const {
+ if (moved_from_) {
+ return "Returned a moved-from instance of the hash state object.";
+ }
+ return *error_;
+ }
+
+ private:
+ template <typename U>
+ friend class SpyHashStateImpl;
+
+ // This is true if SpyHashStateImpl<T> has been passed to a call of
+ // AbslHashValue with the wrong type. This detects that the user called
+ // AbslHashValue directly (because the hash state type does not match).
+ static bool direct_absl_hash_value_error_;
+
+
+ std::vector<std::string> hash_representation_;
+ // This is a shared_ptr because we want all instances of the particular
+ // SpyHashState run to share the field. This way we can set the error for
+ // use-after-move and all the copies will see it.
+ std::shared_ptr<absl::optional<std::string>> error_;
+ bool moved_from_ = false;
+};
+
+template <typename T>
+bool SpyHashStateImpl<T>::direct_absl_hash_value_error_;
+
+template <bool& B>
+struct OdrUse {
+ constexpr OdrUse() {}
+ bool& b = B;
+};
+
+template <void (*)()>
+struct RunOnStartup {
+ static bool run;
+ static constexpr OdrUse<run> kOdrUse{};
+};
+
+template <void (*f)()>
+bool RunOnStartup<f>::run = (f(), true);
+
+template <
+ typename T, typename U,
+ // Only trigger for when (T != U),
+ absl::enable_if_t<!std::is_same<T, U>::value, int> = 0,
+ // This statement works in two ways:
+ // - First, it instantiates RunOnStartup and forces the initialization of
+ // `run`, which set the global variable.
+ // - Second, it triggers a SFINAE error disabling the overload to prevent
+ // compile time errors. If we didn't disable the overload we would get
+ // ambiguous overload errors, which we don't want.
+ int = RunOnStartup<SpyHashStateImpl<T>::SetDirectAbslHashValueError>::run>
+void AbslHashValue(SpyHashStateImpl<T>, const U&);
+
+using SpyHashState = SpyHashStateImpl<void>;
+
+} // namespace hash_internal
+} // inline namespace lts_2018_12_18
+} // namespace absl
+
+#endif // ABSL_HASH_INTERNAL_SPY_HASH_STATE_H_