#ifndef NINJA_MAP_H_
#define NINJA_MAP_H_
#include <algorithm>
#include <string.h>
#include "string_piece.h"
#include "util.h"
static inline
unsigned int MurmurHash2(const void* key, size_t len) {
static const unsigned int seed = 0xDECAFBAD;
const unsigned int m = 0x5bd1e995;
const int r = 24;
unsigned int h = seed ^ len;
const unsigned char* data = (const unsigned char*)key;
while (len >= 4) {
unsigned int k;
memcpy(&k, data, sizeof k);
k *= m;
k ^= k >> r;
k *= m;
h *= m;
h ^= k;
data += 4;
len -= 4;
}
switch (len) {
case 3: h ^= data[2] << 16;
NINJA_FALLTHROUGH;
case 2: h ^= data[1] << 8;
NINJA_FALLTHROUGH;
case 1: h ^= data[0];
h *= m;
};
h ^= h >> 13;
h *= m;
h ^= h >> 15;
return h;
}
#if (__cplusplus >= 201103L) || (_MSC_VER >= 1900)
#include <unordered_map>
namespace std {
template<>
struct hash<StringPiece> {
typedef StringPiece argument_type;
typedef size_t result_type;
size_t operator()(StringPiece key) const {
return MurmurHash2(key.str_, key.len_);
}
};
}
#elif defined(_MSC_VER)
#include <hash_map>
using stdext::hash_map;
using stdext::hash_compare;
struct StringPieceCmp : public hash_compare<StringPiece> {
size_t operator()(const StringPiece& key) const {
return MurmurHash2(key.str_, key.len_);
}
bool operator()(const StringPiece& a, const StringPiece& b) const {
int cmp = memcmp(a.str_, b.str_, min(a.len_, b.len_));
if (cmp < 0) {
return true;
} else if (cmp > 0) {
return false;
} else {
return a.len_ < b.len_;
}
}
};
#else
#include <ext/hash_map>
using __gnu_cxx::hash_map;
namespace __gnu_cxx {
template<>
struct hash<StringPiece> {
size_t operator()(StringPiece key) const {
return MurmurHash2(key.str_, key.len_);
}
};
}
#endif
template<typename V>
struct ExternalStringHashMap {
#if (__cplusplus >= 201103L) || (_MSC_VER >= 1900)
typedef std::unordered_map<StringPiece, V> Type;
#elif defined(_MSC_VER)
typedef hash_map<StringPiece, V, StringPieceCmp> Type;
#else
typedef hash_map<StringPiece, V> Type;
#endif
};
#endif