Multi-dimension rappor metrics

components/rappor/bloom_filter.cc

 // 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 "components/rappor/bloom_filter.h"
 
 #include "base/logging.h"
 #include "third_party/smhasher/src/City.h"
 
 namespace rappor {
 
-BloomFilter::BloomFilter(uint32_t bytes_size,
-                         uint32_t hash_function_count,
-                         uint32_t hash_seed_offset)
-    : bytes_(bytes_size),
-      hash_function_count_(hash_function_count),
-      hash_seed_offset_(hash_seed_offset) {
-  DCHECK_GT(bytes_size, 0u);
-}
+namespace internal {
 
-BloomFilter::~BloomFilter() {}
-
-void BloomFilter::SetString(const std::string& str) {
-  for (size_t i = 0; i < bytes_.size(); ++i) {
-    bytes_[i] = 0;
+void SetBloomBits(uint32_t bytes_size,
+                  uint32_t hash_function_count,
+                  uint32_t hash_seed_offset,
+                  const std::string& str,
+                  ByteVector* output) {
+  DCHECK_GE(output->size(), bytes_size);
+  for (size_t i = 0; i < bytes_size; ++i) {
+    (*output)[i] = 0;
   }
-  for (size_t i = 0; i < hash_function_count_; ++i) {
+  for (size_t i = 0; i < hash_function_count; ++i) {
     // Using CityHash here because we have support for it in Dremel.  Many hash
     // functions, such as MD5, SHA1, or Murmur, would probably also work.
     uint32_t index =
-        CityHash64WithSeed(str.data(), str.size(), hash_seed_offset_ + i);
+        CityHash64WithSeed(str.data(), str.size(), hash_seed_offset + i);
     // Note that the "bytes" are uint8_t, so they are always 8-bits.
-    uint32_t byte_index = (index / 8) % bytes_.size();
+    uint32_t byte_index = (index / 8) % bytes_size;
     uint32_t bit_index = index % 8;
-    bytes_[byte_index] |= 1 << bit_index;
+    (*output)[byte_index] |= 1 << bit_index;
   }
 }
 
-void BloomFilter::SetBytesForTesting(const ByteVector& bytes) {
-  DCHECK_EQ(bytes_.size(), bytes.size());
-  for (size_t i = 0; i < bytes_.size(); ++i) {
-    bytes_[i] = bytes[i];
-  }
-}
+}  // namespace internal
 
 }  // namespace rappor