X-Git-Url: http://plrg.eecs.uci.edu/git/?p=folly.git;a=blobdiff_plain;f=folly%2FHash.h;h=916dfba81436f2f9c0d2aaa540fbe17b76e22912;hp=211dc44ed37838896036fca50a5f4e08cb98079d;hb=acbd746f5036bf795cc62022f0114b4b08032d82;hpb=83b9f93f4f5b536792b36de0e6d601e2a3b894bc

diff --git a/folly/Hash.h b/folly/Hash.h
index 211dc44e..916dfba8 100644
--- a/folly/Hash.h
+++ b/folly/Hash.h
@@ -16,510 +16,5 @@
 
 #pragma once
 
-#include <cstdint>
-#include <cstring>
-#include <limits>
-#include <string>
-#include <tuple>
-#include <type_traits>
-#include <utility>
-
-#include <folly/ApplyTuple.h>
-#include <folly/Bits.h>
-#include <folly/hash/SpookyHashV1.h>
-#include <folly/hash/SpookyHashV2.h>
-
-/*
- * Various hashing functions.
- */
-
-namespace folly { namespace hash {
-
-// This is a general-purpose way to create a single hash from multiple
-// hashable objects. hash_combine_generic takes a class Hasher implementing
-// hash<T>; hash_combine uses a default hasher StdHasher that uses std::hash.
-// hash_combine_generic hashes each argument and combines those hashes in
-// an order-dependent way to yield a new hash.
-
-
-// This is the Hash128to64 function from Google's cityhash (available
-// under the MIT License).  We use it to reduce multiple 64 bit hashes
-// into a single hash.
-inline uint64_t hash_128_to_64(const uint64_t upper, const uint64_t lower) {
-  // Murmur-inspired hashing.
-  const uint64_t kMul = 0x9ddfea08eb382d69ULL;
-  uint64_t a = (lower ^ upper) * kMul;
-  a ^= (a >> 47);
-  uint64_t b = (upper ^ a) * kMul;
-  b ^= (b >> 47);
-  b *= kMul;
-  return b;
-}
-
-// Never used, but gcc demands it.
-template <class Hasher>
-inline size_t hash_combine_generic() {
-  return 0;
-}
-
-template <
-    class Iter,
-    class Hash = std::hash<typename std::iterator_traits<Iter>::value_type>>
-uint64_t hash_range(Iter begin,
-                    Iter end,
-                    uint64_t hash = 0,
-                    Hash hasher = Hash()) {
-  for (; begin != end; ++begin) {
-    hash = hash_128_to_64(hash, hasher(*begin));
-  }
-  return hash;
-}
-
-inline uint32_t twang_32from64(uint64_t key);
-
-template <class Hasher, typename T, typename... Ts>
-size_t hash_combine_generic(const T& t, const Ts&... ts) {
-  size_t seed = Hasher::hash(t);
-  if (sizeof...(ts) == 0) {
-    return seed;
-  }
-  size_t remainder = hash_combine_generic<Hasher>(ts...);
-  /* static */ if (sizeof(size_t) == sizeof(uint32_t)) {
-    return twang_32from64((uint64_t(seed) << 32) | remainder);
-  } else {
-    return static_cast<size_t>(hash_128_to_64(seed, remainder));
-  }
-}
-
-// Simply uses std::hash to hash.  Note that std::hash is not guaranteed
-// to be a very good hash function; provided std::hash doesn't collide on
-// the individual inputs, you are fine, but that won't be true for, say,
-// strings or pairs
-class StdHasher {
- public:
-  template <typename T>
-  static size_t hash(const T& t) {
-    return std::hash<T>()(t);
-  }
-};
-
-template <typename T, typename... Ts>
-size_t hash_combine(const T& t, const Ts&... ts) {
-  return hash_combine_generic<StdHasher>(t, ts...);
-}
-
-//////////////////////////////////////////////////////////////////////
-
-/*
- * Thomas Wang 64 bit mix hash function
- */
-
-inline uint64_t twang_mix64(uint64_t key) {
-  key = (~key) + (key << 21);  // key *= (1 << 21) - 1; key -= 1;
-  key = key ^ (key >> 24);
-  key = key + (key << 3) + (key << 8);  // key *= 1 + (1 << 3) + (1 << 8)
-  key = key ^ (key >> 14);
-  key = key + (key << 2) + (key << 4);  // key *= 1 + (1 << 2) + (1 << 4)
-  key = key ^ (key >> 28);
-  key = key + (key << 31);  // key *= 1 + (1 << 31)
-  return key;
-}
-
-/*
- * Inverse of twang_mix64
- *
- * Note that twang_unmix64 is significantly slower than twang_mix64.
- */
-
-inline uint64_t twang_unmix64(uint64_t key) {
-  // See the comments in jenkins_rev_unmix32 for an explanation as to how this
-  // was generated
-  key *= 4611686016279904257U;
-  key ^= (key >> 28) ^ (key >> 56);
-  key *= 14933078535860113213U;
-  key ^= (key >> 14) ^ (key >> 28) ^ (key >> 42) ^ (key >> 56);
-  key *= 15244667743933553977U;
-  key ^= (key >> 24) ^ (key >> 48);
-  key = (key + 1) * 9223367638806167551U;
-  return key;
-}
-
-/*
- * Thomas Wang downscaling hash function
- */
-
-inline uint32_t twang_32from64(uint64_t key) {
-  key = (~key) + (key << 18);
-  key = key ^ (key >> 31);
-  key = key * 21;
-  key = key ^ (key >> 11);
-  key = key + (key << 6);
-  key = key ^ (key >> 22);
-  return (uint32_t) key;
-}
-
-/*
- * Robert Jenkins' reversible 32 bit mix hash function
- */
-
-inline uint32_t jenkins_rev_mix32(uint32_t key) {
-  key += (key << 12);  // key *= (1 + (1 << 12))
-  key ^= (key >> 22);
-  key += (key << 4);   // key *= (1 + (1 << 4))
-  key ^= (key >> 9);
-  key += (key << 10);  // key *= (1 + (1 << 10))
-  key ^= (key >> 2);
-  // key *= (1 + (1 << 7)) * (1 + (1 << 12))
-  key += (key << 7);
-  key += (key << 12);
-  return key;
-}
-
-/*
- * Inverse of jenkins_rev_mix32
- *
- * Note that jenkinks_rev_unmix32 is significantly slower than
- * jenkins_rev_mix32.
- */
-
-inline uint32_t jenkins_rev_unmix32(uint32_t key) {
-  // These are the modular multiplicative inverses (in Z_2^32) of the
-  // multiplication factors in jenkins_rev_mix32, in reverse order.  They were
-  // computed using the Extended Euclidean algorithm, see
-  // http://en.wikipedia.org/wiki/Modular_multiplicative_inverse
-  key *= 2364026753U;
-
-  // The inverse of a ^= (a >> n) is
-  // b = a
-  // for (int i = n; i < 32; i += n) {
-  //   b ^= (a >> i);
-  // }
-  key ^=
-    (key >> 2) ^ (key >> 4) ^ (key >> 6) ^ (key >> 8) ^
-    (key >> 10) ^ (key >> 12) ^ (key >> 14) ^ (key >> 16) ^
-    (key >> 18) ^ (key >> 20) ^ (key >> 22) ^ (key >> 24) ^
-    (key >> 26) ^ (key >> 28) ^ (key >> 30);
-  key *= 3222273025U;
-  key ^= (key >> 9) ^ (key >> 18) ^ (key >> 27);
-  key *= 4042322161U;
-  key ^= (key >> 22);
-  key *= 16773121U;
-  return key;
-}
-
-/*
- * Fowler / Noll / Vo (FNV) Hash
- *     http://www.isthe.com/chongo/tech/comp/fnv/
- */
-
-const uint32_t FNV_32_HASH_START = 2166136261UL;
-const uint64_t FNV_64_HASH_START = 14695981039346656037ULL;
-const uint64_t FNVA_64_HASH_START = 14695981039346656037ULL;
-
-inline uint32_t fnv32(const char* buf, uint32_t hash = FNV_32_HASH_START) {
-  // forcing signed char, since other platforms can use unsigned
-  const signed char* s = reinterpret_cast<const signed char*>(buf);
-
-  for (; *s; ++s) {
-    hash += (hash << 1) + (hash << 4) + (hash << 7) +
-            (hash << 8) + (hash << 24);
-    hash ^= *s;
-  }
-  return hash;
-}
-
-inline uint32_t fnv32_buf(const void* buf,
-                          size_t n,
-                          uint32_t hash = FNV_32_HASH_START) {
-  // forcing signed char, since other platforms can use unsigned
-  const signed char* char_buf = reinterpret_cast<const signed char*>(buf);
-
-  for (size_t i = 0; i < n; ++i) {
-    hash += (hash << 1) + (hash << 4) + (hash << 7) +
-            (hash << 8) + (hash << 24);
-    hash ^= char_buf[i];
-  }
-
-  return hash;
-}
-
-inline uint32_t fnv32(const std::string& str,
-                      uint32_t hash = FNV_32_HASH_START) {
-  return fnv32_buf(str.data(), str.size(), hash);
-}
-
-inline uint64_t fnv64(const char* buf, uint64_t hash = FNV_64_HASH_START) {
-  // forcing signed char, since other platforms can use unsigned
-  const signed char* s = reinterpret_cast<const signed char*>(buf);
-
-  for (; *s; ++s) {
-    hash += (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) +
-      (hash << 8) + (hash << 40);
-    hash ^= *s;
-  }
-  return hash;
-}
-
-inline uint64_t fnv64_buf(const void* buf,
-                          size_t n,
-                          uint64_t hash = FNV_64_HASH_START) {
-  // forcing signed char, since other platforms can use unsigned
-  const signed char* char_buf = reinterpret_cast<const signed char*>(buf);
-
-  for (size_t i = 0; i < n; ++i) {
-    hash += (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) +
-      (hash << 8) + (hash << 40);
-    hash ^= char_buf[i];
-  }
-  return hash;
-}
-
-inline uint64_t fnv64(const std::string& str,
-                      uint64_t hash = FNV_64_HASH_START) {
-  return fnv64_buf(str.data(), str.size(), hash);
-}
-
-inline uint64_t fnva64_buf(const void* buf,
-                           size_t n,
-                           uint64_t hash = FNVA_64_HASH_START) {
-  const uint8_t* char_buf = reinterpret_cast<const uint8_t*>(buf);
-
-  for (size_t i = 0; i < n; ++i) {
-    hash ^= char_buf[i];
-    hash += (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) +
-            (hash << 8) + (hash << 40);
-  }
-  return hash;
-}
-
-inline uint64_t fnva64(const std::string& str,
-                       uint64_t hash = FNVA_64_HASH_START) {
-  return fnva64_buf(str.data(), str.size(), hash);
-}
-
-/*
- * Paul Hsieh: http://www.azillionmonkeys.com/qed/hash.html
- */
-
-#define get16bits(d) folly::loadUnaligned<uint16_t>(d)
-
-inline uint32_t hsieh_hash32_buf(const void* buf, size_t len) {
-  // forcing signed char, since other platforms can use unsigned
-  const unsigned char* s = reinterpret_cast<const unsigned char*>(buf);
-  uint32_t hash = static_cast<uint32_t>(len);
-  uint32_t tmp;
-  size_t rem;
-
-  if (len <= 0 || buf == 0) {
-    return 0;
-  }
-
-  rem = len & 3;
-  len >>= 2;
-
-  /* Main loop */
-  for (;len > 0; len--) {
-    hash  += get16bits (s);
-    tmp    = (get16bits (s+2) << 11) ^ hash;
-    hash   = (hash << 16) ^ tmp;
-    s  += 2*sizeof (uint16_t);
-    hash  += hash >> 11;
-  }
-
-  /* Handle end cases */
-  switch (rem) {
-  case 3:
-    hash += get16bits(s);
-    hash ^= hash << 16;
-    hash ^= s[sizeof (uint16_t)] << 18;
-    hash += hash >> 11;
-    break;
-  case 2:
-    hash += get16bits(s);
-    hash ^= hash << 11;
-    hash += hash >> 17;
-    break;
-  case 1:
-    hash += *s;
-    hash ^= hash << 10;
-    hash += hash >> 1;
-  }
-
-  /* Force "avalanching" of final 127 bits */
-  hash ^= hash << 3;
-  hash += hash >> 5;
-  hash ^= hash << 4;
-  hash += hash >> 17;
-  hash ^= hash << 25;
-  hash += hash >> 6;
-
-  return hash;
-};
-
-#undef get16bits
-
-inline uint32_t hsieh_hash32(const char* s) {
-  return hsieh_hash32_buf(s, std::strlen(s));
-}
-
-inline uint32_t hsieh_hash32_str(const std::string& str) {
-  return hsieh_hash32_buf(str.data(), str.size());
-}
-
-//////////////////////////////////////////////////////////////////////
-
-} // namespace hash
-
-template <class Key, class Enable = void>
-struct hasher;
-
-struct Hash {
-  template <class T>
-  size_t operator()(const T& v) const {
-    return hasher<T>()(v);
-  }
-
-  template <class T, class... Ts>
-  size_t operator()(const T& t, const Ts&... ts) const {
-    return hash::hash_128_to_64((*this)(t), (*this)(ts...));
-  }
-};
-
-template <>
-struct hasher<bool> {
-  size_t operator()(bool key) const {
-    // Make sure that all the output bits depend on the input.
-    return key ? std::numeric_limits<size_t>::max() : 0;
-  }
-};
-
-template <> struct hasher<int32_t> {
-  size_t operator()(int32_t key) const {
-    return hash::jenkins_rev_mix32(uint32_t(key));
-  }
-};
-
-template <> struct hasher<uint32_t> {
-  size_t operator()(uint32_t key) const {
-    return hash::jenkins_rev_mix32(key);
-  }
-};
-
-template <> struct hasher<int16_t> {
-  size_t operator()(int16_t key) const {
-    return hasher<int32_t>()(key); // as impl accident, sign-extends
-  }
-};
-
-template <> struct hasher<uint16_t> {
-  size_t operator()(uint16_t key) const {
-    return hasher<uint32_t>()(key);
-  }
-};
-
-template <> struct hasher<int8_t> {
-  size_t operator()(int8_t key) const {
-    return hasher<int32_t>()(key); // as impl accident, sign-extends
-  }
-};
-
-template <> struct hasher<uint8_t> {
-  size_t operator()(uint8_t key) const {
-    return hasher<uint32_t>()(key);
-  }
-};
-
-template <> struct hasher<char> {
-  using explicit_type =
-      std::conditional<std::is_signed<char>::value, int8_t, uint8_t>::type;
-  size_t operator()(char key) const {
-    return hasher<explicit_type>()(key); // as impl accident, sign-extends
-  }
-};
-
-template <> struct hasher<int64_t> {
-  size_t operator()(int64_t key) const {
-    return static_cast<size_t>(hash::twang_mix64(uint64_t(key)));
-  }
-};
-
-template <> struct hasher<uint64_t> {
-  size_t operator()(uint64_t key) const {
-    return static_cast<size_t>(hash::twang_mix64(key));
-  }
-};
-
-template <> struct hasher<std::string> {
-  size_t operator()(const std::string& key) const {
-    return static_cast<size_t>(
-        hash::SpookyHashV2::Hash64(key.data(), key.size(), 0));
-  }
-};
-
-template <class T>
-struct hasher<T, typename std::enable_if<std::is_enum<T>::value, void>::type> {
-  size_t operator()(T key) const {
-    return Hash()(static_cast<typename std::underlying_type<T>::type>(key));
-  }
-};
-
-template <class T1, class T2>
-struct hasher<std::pair<T1, T2>> {
-  size_t operator()(const std::pair<T1, T2>& key) const {
-    return Hash()(key.first, key.second);
-  }
-};
-
-template <typename... Ts>
-struct hasher<std::tuple<Ts...>> {
-  size_t operator() (const std::tuple<Ts...>& key) const {
-    return applyTuple(Hash(), key);
-  }
-};
-
-// recursion
-template <size_t index, typename... Ts>
-struct TupleHasher {
-  size_t operator()(std::tuple<Ts...> const& key) const {
-    return hash::hash_combine(
-      TupleHasher<index - 1, Ts...>()(key),
-      std::get<index>(key));
-  }
-};
-
-// base
-template <typename... Ts>
-struct TupleHasher<0, Ts...> {
-  size_t operator()(std::tuple<Ts...> const& key) const {
-    // we could do std::hash here directly, but hash_combine hides all the
-    // ugly templating implicitly
-    return hash::hash_combine(std::get<0>(key));
-  }
-};
-
-} // namespace folly
-
-// Custom hash functions.
-namespace std {
-  // Hash function for pairs. Requires default hash functions for both
-  // items in the pair.
-  template <typename T1, typename T2>
-  struct hash<std::pair<T1, T2> > {
-   public:
-    size_t operator()(const std::pair<T1, T2>& x) const {
-      return folly::hash::hash_combine(x.first, x.second);
-    }
-  };
-
-  // Hash function for tuples. Requires default hash functions for all types.
-  template <typename... Ts>
-  struct hash<std::tuple<Ts...>> {
-    size_t operator()(std::tuple<Ts...> const& key) const {
-      folly::TupleHasher<
-        std::tuple_size<std::tuple<Ts...>>::value - 1, // start index
-        Ts...> hasher;
-
-      return hasher(key);
-    }
-  };
-} // namespace std
+//  shims:
+#include <folly/hash/Hash.h>