// Copyright 2014 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "base/metrics/metrics_hashes.h" #include #include "base/check_op.h" #include "base/hash/md5.h" #include "base/sys_byteorder.h" namespace base { namespace { // Converts the 8-byte prefix of an MD5 hash into a uint64_t value. inline uint64_t DigestToUInt64(const base::MD5Digest& digest) { uint64_t value; DCHECK_GE(sizeof(digest.a), sizeof(value)); memcpy(&value, digest.a, sizeof(value)); return base::NetToHost64(value); } // Converts the 4-byte prefix of an MD5 hash into a uint32_t value. inline uint32_t DigestToUInt32(const base::MD5Digest& digest) { uint32_t value; DCHECK_GE(sizeof(digest.a), sizeof(value)); memcpy(&value, digest.a, sizeof(value)); return base::NetToHost32(value); } } // namespace uint64_t HashMetricName(base::StringPiece name) { // Corresponding Python code for quick look up: // // import struct // import hashlib // struct.unpack('>Q', hashlib.md5(name.encode('utf-8')).digest()[:8])[0] // base::MD5Digest digest; base::MD5Sum(name.data(), name.size(), &digest); return DigestToUInt64(digest); } uint32_t HashMetricNameAs32Bits(base::StringPiece name) { base::MD5Digest digest; base::MD5Sum(name.data(), name.size(), &digest); return DigestToUInt32(digest); } } // namespace base