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 "components/metrics/metrics_hashes.h" 6 7 #include "base/logging.h" 8 #include "base/md5.h" 9 #include "base/sys_byteorder.h" 10 11 namespace metrics { 12 13 namespace { 14 15 // Converts the 8-byte prefix of an MD5 hash into a uint64 value. 16 inline uint64 HashToUInt64(const std::string& hash) { 17 uint64 value; 18 DCHECK_GE(hash.size(), sizeof(value)); 19 memcpy(&value, hash.data(), sizeof(value)); 20 return base::HostToNet64(value); 21 } 22 23 } // namespace 24 25 uint64 HashMetricName(const std::string& name) { 26 // Create an MD5 hash of the given |name|, represented as a byte buffer 27 // encoded as an std::string. 28 base::MD5Context context; 29 base::MD5Init(&context); 30 base::MD5Update(&context, name); 31 32 base::MD5Digest digest; 33 base::MD5Final(&digest, &context); 34 35 std::string hash_str(reinterpret_cast<char*>(digest.a), arraysize(digest.a)); 36 return HashToUInt64(hash_str); 37 } 38 39 } // namespace metrics 40
