1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "base/metrics/metrics_hashes.h" 6 7 #include "base/logging.h" 8 #include "base/md5.h" 9 #include "base/sys_byteorder.h" 10 11 namespace base { 12 13 namespace { 14 15 // Converts the 8-byte prefix of an MD5 hash into a uint64_t value. 16 inline uint64_t DigestToUInt64(const base::MD5Digest& digest) { 17 uint64_t value; 18 DCHECK_GE(sizeof(digest.a), sizeof(value)); 19 memcpy(&value, digest.a, sizeof(value)); 20 return base::NetToHost64(value); 21 } 22 23 } // namespace 24 25 uint64_t HashMetricName(base::StringPiece name) { 26 base::MD5Digest digest; 27 base::MD5Sum(name.data(), name.size(), &digest); 28 return DigestToUInt64(digest); 29 } 30 31 } // namespace metrics 32
