gecko/mfbt/HashFunctions.cpp

38 lines
970 B
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* Implementations of hash functions. */
#include "mozilla/HashFunctions.h"
#include <string.h>
namespace mozilla {
MFBT_API(uint32_t)
HashBytes(const void* bytes, size_t length)
{
uint32_t hash = 0;
const char* b = reinterpret_cast<const char*>(bytes);
/* Walk word by word. */
size_t i = 0;
for (; i < length - (length % sizeof(size_t)); i += sizeof(size_t)) {
/* Do an explicitly unaligned load of the data. */
size_t data;
memcpy(&data, b + i, sizeof(size_t));
hash = AddToHash(hash, data, sizeof(data));
}
/* Get the remaining bytes. */
for (; i < length; i++)
hash = AddToHash(hash, b[i]);
return hash;
}
} /* namespace mozilla */