components/rappor/rappor_parameters.h

   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 #ifndef COMPONENTS_RAPPOR_RAPPOR_PARAMETERS_H_
   6 #define COMPONENTS_RAPPOR_RAPPOR_PARAMETERS_H_
   7
   8 #include <string>
   9
  10 namespace rappor {
  11
  12 enum Probability {
  13   PROBABILITY_75,    // 75%
  14   PROBABILITY_50,    // 50%
  15 };
  16
  17 // An object describing a rappor metric and the parameters used to generate it.
  18 //
  19 // For a full description of the rappor metrics, see
  20 // http://www.chromium.org/developers/design-documents/rappor
  21 struct RapporParameters {
  22   // Get a string representing the parameters, for DCHECK_EQ.
  23   std::string ToString() const;
  24
  25   // The number of bytes stored in the Bloom filter.
  26   int bloom_filter_size_bytes;
  27   // The number of hash functions used in the Bloom filter.
  28   int bloom_filter_hash_function_count;
  29
  30   // The probability that a bit will be redacted with fake data.
  31   Probability fake_prob;
  32   // The probability that a fake bit will be a one.
  33   Probability fake_one_prob;
  34
  35   // The probability that a one bit in the redacted data reports as one.
  36   Probability one_coin_prob;
  37   // The probability that a zero bit in the redacted data reports as one.
  38   Probability zero_coin_prob;
  39 };
  40
  41 }  // namespace rappor
  42
  43 #endif  // COMPONENTS_RAPPOR_RAPPOR_PARAMETERS_H_