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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 // | 4 // |
5 // BucketRanges stores the vector of ranges that delimit what samples are | 5 // BucketRanges stores the vector of ranges that delimit what samples are |
6 // tallied in the corresponding buckets of a histogram. Histograms that have | 6 // tallied in the corresponding buckets of a histogram. Histograms that have |
7 // same ranges for all their corresponding buckets should share the same | 7 // same ranges for all their corresponding buckets should share the same |
8 // BucketRanges object. | 8 // BucketRanges object. |
9 // | 9 // |
10 // E.g. A 5 buckets LinearHistogram with 1 as minimal value and 4 as maximal | 10 // E.g. A 5 buckets LinearHistogram with 1 as minimal value and 4 as maximal |
11 // value will need a BucketRanges with 6 ranges: | 11 // value will need a BucketRanges with 6 ranges: |
12 // 0, 1, 2, 3, 4, INT_MAX | 12 // 0, 1, 2, 3, 4, INT_MAX |
13 // | 13 // |
14 // TODO(kaiwang): Currently we keep all negative values in 0~1 bucket. Consider | 14 // TODO(kaiwang): Currently we keep all negative values in 0~1 bucket. Consider |
15 // changing 0 to INT_MIN. | 15 // changing 0 to INT_MIN. |
16 | 16 |
17 #ifndef BASE_METRICS_BUCKET_RANGES_H_ | 17 #ifndef BASE_METRICS_BUCKET_RANGES_H_ |
18 #define BASE_METRICS_BUCKET_RANGES_H_ | 18 #define BASE_METRICS_BUCKET_RANGES_H_ |
19 | 19 |
| 20 #include <stddef.h> |
| 21 #include <stdint.h> |
| 22 |
20 #include <vector> | 23 #include <vector> |
21 | 24 |
| 25 #include <limits.h> |
| 26 |
22 #include "base/base_export.h" | 27 #include "base/base_export.h" |
23 #include "base/basictypes.h" | 28 #include "base/macros.h" |
24 #include "base/metrics/histogram_base.h" | 29 #include "base/metrics/histogram_base.h" |
25 | 30 |
26 namespace base { | 31 namespace base { |
27 | 32 |
28 class BASE_EXPORT BucketRanges { | 33 class BASE_EXPORT BucketRanges { |
29 public: | 34 public: |
30 typedef std::vector<HistogramBase::Sample> Ranges; | 35 typedef std::vector<HistogramBase::Sample> Ranges; |
31 | 36 |
32 explicit BucketRanges(size_t num_ranges); | 37 explicit BucketRanges(size_t num_ranges); |
33 ~BucketRanges(); | 38 ~BucketRanges(); |
34 | 39 |
35 size_t size() const { return ranges_.size(); } | 40 size_t size() const { return ranges_.size(); } |
36 HistogramBase::Sample range(size_t i) const { return ranges_[i]; } | 41 HistogramBase::Sample range(size_t i) const { return ranges_[i]; } |
37 void set_range(size_t i, HistogramBase::Sample value); | 42 void set_range(size_t i, HistogramBase::Sample value); |
38 uint32 checksum() const { return checksum_; } | 43 uint32_t checksum() const { return checksum_; } |
39 void set_checksum(uint32 checksum) { checksum_ = checksum; } | 44 void set_checksum(uint32_t checksum) { checksum_ = checksum; } |
40 | 45 |
41 // A bucket is defined by a consecutive pair of entries in |ranges|, so there | 46 // A bucket is defined by a consecutive pair of entries in |ranges|, so there |
42 // is one fewer bucket than there are ranges. For example, if |ranges| is | 47 // is one fewer bucket than there are ranges. For example, if |ranges| is |
43 // [0, 1, 3, 7, INT_MAX], then the buckets in this histogram are | 48 // [0, 1, 3, 7, INT_MAX], then the buckets in this histogram are |
44 // [0, 1), [1, 3), [3, 7), and [7, INT_MAX). | 49 // [0, 1), [1, 3), [3, 7), and [7, INT_MAX). |
45 size_t bucket_count() const { return ranges_.size() - 1; } | 50 size_t bucket_count() const { return ranges_.size() - 1; } |
46 | 51 |
47 // Checksum methods to verify whether the ranges are corrupted (e.g. bad | 52 // Checksum methods to verify whether the ranges are corrupted (e.g. bad |
48 // memory access). | 53 // memory access). |
49 uint32 CalculateChecksum() const; | 54 uint32_t CalculateChecksum() const; |
50 bool HasValidChecksum() const; | 55 bool HasValidChecksum() const; |
51 void ResetChecksum(); | 56 void ResetChecksum(); |
52 | 57 |
53 // Return true iff |other| object has same ranges_ as |this| object's ranges_. | 58 // Return true iff |other| object has same ranges_ as |this| object's ranges_. |
54 bool Equals(const BucketRanges* other) const; | 59 bool Equals(const BucketRanges* other) const; |
55 | 60 |
56 private: | 61 private: |
57 // A monotonically increasing list of values which determine which bucket to | 62 // A monotonically increasing list of values which determine which bucket to |
58 // put a sample into. For each index, show the smallest sample that can be | 63 // put a sample into. For each index, show the smallest sample that can be |
59 // added to the corresponding bucket. | 64 // added to the corresponding bucket. |
60 Ranges ranges_; | 65 Ranges ranges_; |
61 | 66 |
62 // Checksum for the conntents of ranges_. Used to detect random over-writes | 67 // Checksum for the conntents of ranges_. Used to detect random over-writes |
63 // of our data, and to quickly see if some other BucketRanges instance is | 68 // of our data, and to quickly see if some other BucketRanges instance is |
64 // possibly Equal() to this instance. | 69 // possibly Equal() to this instance. |
65 // TODO(kaiwang): Consider change this to uint64. Because we see a lot of | 70 // TODO(kaiwang): Consider change this to uint64_t. Because we see a lot of |
66 // noise on UMA dashboard. | 71 // noise on UMA dashboard. |
67 uint32 checksum_; | 72 uint32_t checksum_; |
68 | 73 |
69 DISALLOW_COPY_AND_ASSIGN(BucketRanges); | 74 DISALLOW_COPY_AND_ASSIGN(BucketRanges); |
70 }; | 75 }; |
71 | 76 |
72 ////////////////////////////////////////////////////////////////////////////// | 77 ////////////////////////////////////////////////////////////////////////////// |
73 // Expose only for test. | 78 // Expose only for test. |
74 BASE_EXPORT extern const uint32 kCrcTable[256]; | 79 BASE_EXPORT extern const uint32_t kCrcTable[256]; |
75 | 80 |
76 } // namespace base | 81 } // namespace base |
77 | 82 |
78 #endif // BASE_METRICS_BUCKET_RANGES_H_ | 83 #endif // BASE_METRICS_BUCKET_RANGES_H_ |
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