Index: components/rappor/rappor_metric.cc |
diff --git a/components/rappor/rappor_metric.cc b/components/rappor/rappor_metric.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..38a5342af46164ff776304259c9ff94c240bc73f |
--- /dev/null |
+++ b/components/rappor/rappor_metric.cc |
@@ -0,0 +1,45 @@ |
+// Copyright (c) 2012 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/rappor_metric.h" |
+ |
+namespace rappor { |
+ |
+RapporMetric::RapporMetric(const RapporParameters& parameters) |
+ : parameters_(parameters), |
+ bloom_(parameters.bloom_filter_size_bytes, |
+ parameters.bloom_filter_hash_count) {} |
+ |
+void RapporMetric::AddSamples(const std::vector<std::string>& strings) { |
+ bloom_.AddStrings(strings); |
+} |
+ |
+void RapporMetric::AddSample(const std::string& str) { bloom_.AddString(str); } |
+ |
+const ByteVector& RapporMetric::GetBytes() const { return bloom_.bytes(); } |
+ |
+ByteVector RapporMetric::GetReport(const std::string& secret) const { |
+ ByteVector real_bits(GetBytes()); |
+ |
+ HmacByteVectorGenerator hmac_generator(real_bits.size(), |
+ secret + parameters()->rappor_name); |
+ const ByteVector fake_mask = |
+ hmac_generator.GetWeightedRandomByteVector(parameters()->fake_prob); |
+ const ByteVector fake_ones = |
+ hmac_generator.GetWeightedRandomByteVector(parameters()->fake_one_prob); |
+ |
+ const ByteVector* onebits = ByteVectorMerge(&real_bits, fake_ones, fake_mask); |
+ |
+ ByteVectorGenerator coinGenerator(real_bits.size()); |
+ ByteVector zero_coins = |
+ coinGenerator.GetWeightedRandomByteVector(parameters()->zero_coin_prob); |
+ const ByteVector one_coins = |
+ coinGenerator.GetWeightedRandomByteVector(parameters()->one_coin_prob); |
+ |
+ const ByteVector* output = ByteVectorMerge(&zero_coins, one_coins, *onebits); |
+ |
+ return *output; |
+} |
+ |
+} // namespace rappor |