// 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.
#ifndef BASE_METRICS_HISTOGRAM_MACROS_H_
#define BASE_METRICS_HISTOGRAM_MACROS_H_
#include "base/metrics/histogram.h"
#include "base/metrics/histogram_macros_internal.h"
#include "base/metrics/histogram_macros_local.h"
#include "base/time/time.h"
// Macros for efficient use of histograms.
//
// For best practices on deciding when to emit to a histogram and what form
// the histogram should take, see
// https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md
// TODO(rkaplow): Link to proper documentation on metric creation once we have
// it in a good state.
// All of these macros must be called with |name| as a runtime constant - it
// doesn't have to literally be a constant, but it must be the same string on
// all calls from a particular call site. If this rule is violated, it is
// possible the data will be written to the wrong histogram.
//------------------------------------------------------------------------------
// Enumeration histograms.
// These macros create histograms for enumerated data. Ideally, the data should
// be of the form of "event occurs, log the result". We recommended not putting
// related but not directly connected data as enums within the same histogram.
// You should be defining an associated Enum, and the input sample should be
// an element of the Enum.
// All of these macros must be called with |name| as a runtime constant.
// Sample usage:
// UMA_HISTOGRAM_ENUMERATION("My.Enumeration", VALUE, EVENT_MAX_VALUE);
// New Enum values can be added, but existing enums must never be renumbered or
// delete and reused. The value in |sample| must be strictly less than
// |enum_max|.
#define UMA_HISTOGRAM_ENUMERATION(name, sample, enum_max) \
INTERNAL_HISTOGRAM_ENUMERATION_WITH_FLAG( \
name, sample, enum_max, base::HistogramBase::kUmaTargetedHistogramFlag)
// Histogram for boolean values.
// Sample usage:
// UMA_HISTOGRAM_BOOLEAN("Histogram.Boolean", bool);
#define UMA_HISTOGRAM_BOOLEAN(name, sample) \
STATIC_HISTOGRAM_POINTER_BLOCK(name, AddBoolean(sample), \
base::BooleanHistogram::FactoryGet(name, \
base::HistogramBase::kUmaTargetedHistogramFlag))
//------------------------------------------------------------------------------
// Linear histograms.
// All of these macros must be called with |name| as a runtime constant.
// Used for capturing integer data with a linear bucketing scheme. This can be
// used when you want the exact value of some small numeric count, with a max of
// 100 or less. If you need to capture a range of greater than 100, we recommend
// the use of the COUNT histograms below.
// Sample usage:
// UMA_HISTOGRAM_EXACT_LINEAR("Histogram.Linear", count, 10);
#define UMA_HISTOGRAM_EXACT_LINEAR(name, sample, value_max) \
INTERNAL_HISTOGRAM_EXACT_LINEAR_WITH_FLAG( \
name, sample, value_max, base::HistogramBase::kUmaTargetedHistogramFlag)
// Used for capturing basic percentages. This will be 100 buckets of size 1.
// Sample usage:
// UMA_HISTOGRAM_PERCENTAGE("Histogram.Percent", percent_as_int);
#define UMA_HISTOGRAM_PERCENTAGE(name, percent_as_int) \
UMA_HISTOGRAM_EXACT_LINEAR(name, percent_as_int, 101)
//------------------------------------------------------------------------------
// Count histograms. These are used for collecting numeric data. Note that we
// have macros for more specialized use cases below (memory, time, percentages).
// The number suffixes here refer to the max size of the sample, i.e. COUNT_1000
// will be able to collect samples of counts up to 1000. The default number of
// buckets in all default macros is 50. We recommend erring on the side of too
// large a range versus too short a range.
// These macros default to exponential histograms - i.e. the lengths of the
// bucket ranges exponentially increase as the sample range increases.
// These should *not* be used if you are interested in exact counts, i.e. a
// bucket range of 1. In these cases, you should use the ENUMERATION macros
// defined later. These should also not be used to capture the number of some
// event, i.e. "button X was clicked N times". In this cases, an enum should be
// used, ideally with an appropriate baseline enum entry included.
// All of these macros must be called with |name| as a runtime constant.
// Sample usage:
// UMA_HISTOGRAM_COUNTS_1M("My.Histogram", sample);
#define UMA_HISTOGRAM_COUNTS_100(name, sample) UMA_HISTOGRAM_CUSTOM_COUNTS( \
name, sample, 1, 100, 50)
#define UMA_HISTOGRAM_COUNTS_1000(name, sample) UMA_HISTOGRAM_CUSTOM_COUNTS( \
name, sample, 1, 1000, 50)
#define UMA_HISTOGRAM_COUNTS_10000(name, sample) UMA_HISTOGRAM_CUSTOM_COUNTS( \
name, sample, 1, 10000, 50)
#define UMA_HISTOGRAM_COUNTS_100000(name, sample) UMA_HISTOGRAM_CUSTOM_COUNTS( \
name, sample, 1, 100000, 50)
#define UMA_HISTOGRAM_COUNTS_1M(name, sample) UMA_HISTOGRAM_CUSTOM_COUNTS( \
name, sample, 1, 1000000, 50)
#define UMA_HISTOGRAM_COUNTS_10M(name, sample) UMA_HISTOGRAM_CUSTOM_COUNTS( \
name, sample, 1, 10000000, 50)
// This can be used when the default ranges are not sufficient. This macro lets
// the metric developer customize the min and max of the sampled range, as well
// as the number of buckets recorded.
// Any data outside the range here will be put in underflow and overflow
// buckets. Min values should be >=1 as emitted 0s will still go into the
// underflow bucket.
// Sample usage:
// UMA_HISTOGRAM_CUSTOM_COUNTS("My.Histogram", 1, 100000000, 100);
#define UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, bucket_count) \
INTERNAL_HISTOGRAM_CUSTOM_COUNTS_WITH_FLAG( \
name, sample, min, max, bucket_count, \
base::HistogramBase::kUmaTargetedHistogramFlag)
//------------------------------------------------------------------------------
// Timing histograms. These are used for collecting timing data (generally
// latencies).
// These macros create exponentially sized histograms (lengths of the bucket
// ranges exponentially increase as the sample range increases). The input
// sample is a base::TimeDelta. The output data is measured in ms granularity.
// All of these macros must be called with |name| as a runtime constant.
// Sample usage:
// UMA_HISTOGRAM_TIMES("My.Timing.Histogram", time_delta);
// Short timings - up to 10 seconds.
#define UMA_HISTOGRAM_TIMES(name, sample) UMA_HISTOGRAM_CUSTOM_TIMES( \
name, sample, base::TimeDelta::FromMilliseconds(1), \
base::TimeDelta::FromSeconds(10), 50)
// Medium timings - up to 3 minutes. Note this starts at 10ms (no good reason,
// but not worth changing).
#define UMA_HISTOGRAM_MEDIUM_TIMES(name, sample) UMA_HISTOGRAM_CUSTOM_TIMES( \
name, sample, base::TimeDelta::FromMilliseconds(10), \
base::TimeDelta::FromMinutes(3), 50)
// Long timings - up to an hour.
#define UMA_HISTOGRAM_LONG_TIMES(name, sample) UMA_HISTOGRAM_CUSTOM_TIMES( \
name, sample, base::TimeDelta::FromMilliseconds(1), \
base::TimeDelta::FromHours(1), 50)
// Long timings with higher granularity - up to an hour with 100 buckets.
#define UMA_HISTOGRAM_LONG_TIMES_100(name, sample) UMA_HISTOGRAM_CUSTOM_TIMES( \
name, sample, base::TimeDelta::FromMilliseconds(1), \
base::TimeDelta::FromHours(1), 100)
// This can be used when the default ranges are not sufficient. This macro lets
// the metric developer customize the min and max of the sampled range, as well
// as the number of buckets recorded.
// Sample usage:
// UMA_HISTOGRAM_CUSTOM_TIMES("Very.Long.Timing.Histogram", duration_in_ms,
// base::TimeDelta::FromSeconds(1), base::TimeDelta::FromDays(1), 100);
#define UMA_HISTOGRAM_CUSTOM_TIMES(name, sample, min, max, bucket_count) \
STATIC_HISTOGRAM_POINTER_BLOCK(name, AddTime(sample), \
base::Histogram::FactoryTimeGet(name, min, max, bucket_count, \
base::HistogramBase::kUmaTargetedHistogramFlag))
// Scoped class which logs its time on this earth as a UMA statistic. This is
// recommended for when you want a histogram which measures the time it takes
// for a method to execute. This measures up to 10 seconds. It uses
// UMA_HISTOGRAM_TIMES under the hood.
// Sample usage:
// void Function() {
// SCOPED_UMA_HISTOGRAM_TIMER("Component.FunctionTime");
// ...
// }
#define SCOPED_UMA_HISTOGRAM_TIMER(name) \
INTERNAL_SCOPED_UMA_HISTOGRAM_TIMER_EXPANDER(name, false, __COUNTER__)
// Similar scoped histogram timer, but this uses UMA_HISTOGRAM_LONG_TIMES_100,
// which measures up to an hour, and uses 100 buckets. This is more expensive
// to store, so only use if this often takes >10 seconds.
#define SCOPED_UMA_HISTOGRAM_LONG_TIMER(name) \
INTERNAL_SCOPED_UMA_HISTOGRAM_TIMER_EXPANDER(name, true, __COUNTER__)
//------------------------------------------------------------------------------
// Memory histograms.
// These macros create exponentially sized histograms (lengths of the bucket
// ranges exponentially increase as the sample range increases). The input
// sample must be a number measured in kilobytes.
// All of these macros must be called with |name| as a runtime constant.
// Sample usage:
// UMA_HISTOGRAM_MEMORY_KB("My.Memory.Histogram", memory_in_kb);
// Used to measure common KB-granularity memory stats. Range is up to 500000KB -
// approximately 500M.
#define UMA_HISTOGRAM_MEMORY_KB(name, sample) \
UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, 1000, 500000, 50)
// Used to measure common MB-granularity memory stats. Range is up to ~64G.
#define UMA_HISTOGRAM_MEMORY_LARGE_MB(name, sample) \
UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, 1, 64000, 100)
//------------------------------------------------------------------------------
// Stability-specific histograms.
// Histograms logged in as stability histograms will be included in the initial
// stability log. See comments by declaration of
// MetricsService::PrepareInitialStabilityLog().
// All of these macros must be called with |name| as a runtime constant.
// For details on usage, see the documentation on the non-stability equivalents.
#define UMA_STABILITY_HISTOGRAM_COUNTS_100(name, sample) \
UMA_STABILITY_HISTOGRAM_CUSTOM_COUNTS(name, sample, 1, 100, 50)
#define UMA_STABILITY_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, \
bucket_count) \
INTERNAL_HISTOGRAM_CUSTOM_COUNTS_WITH_FLAG( \
name, sample, min, max, bucket_count, \
base::HistogramBase::kUmaStabilityHistogramFlag)
#define UMA_STABILITY_HISTOGRAM_ENUMERATION(name, sample, enum_max) \
INTERNAL_HISTOGRAM_ENUMERATION_WITH_FLAG( \
name, sample, enum_max, \
base::HistogramBase::kUmaStabilityHistogramFlag)
//------------------------------------------------------------------------------
// Sparse histograms.
// Sparse histograms are well suited for recording counts of exact sample values
// that are sparsely distributed over a large range.
//
// UMA_HISTOGRAM_SPARSE_SLOWLY is good for sparsely distributed and/or
// infrequently recorded values since the implementation is slower
// and takes more memory.
//
// For instance, Sqlite.Version.* are sparse because for any given database,
// there's going to be exactly one version logged.
// The |sample| can be a negative or non-negative number.
#define UMA_HISTOGRAM_SPARSE_SLOWLY(name, sample) \
INTERNAL_HISTOGRAM_SPARSE_SLOWLY(name, sample)
//------------------------------------------------------------------------------
// Histogram instantiation helpers.
// Support a collection of histograms, perhaps one for each entry in an
// enumeration. This macro manages a block of pointers, adding to a specific
// one by its index.
//
// A typical instantiation looks something like this:
// STATIC_HISTOGRAM_POINTER_GROUP(
// GetHistogramNameForIndex(histogram_index),
// histogram_index, MAXIMUM_HISTOGRAM_INDEX, Add(some_delta),
// base::Histogram::FactoryGet(
// GetHistogramNameForIndex(histogram_index),
// MINIMUM_SAMPLE, MAXIMUM_SAMPLE, BUCKET_COUNT,
// base::HistogramBase::kUmaTargetedHistogramFlag));
//
// Though it seems inefficient to generate the name twice, the first
// instance will be used only for DCHECK builds and the second will
// execute only during the first access to the given index, after which
// the pointer is cached and the name never needed again.
#define STATIC_HISTOGRAM_POINTER_GROUP(constant_histogram_name, index, \
constant_maximum, \
histogram_add_method_invocation, \
histogram_factory_get_invocation) \
do { \
static base::subtle::AtomicWord atomic_histograms[constant_maximum]; \
DCHECK_LE(0, index); \
DCHECK_LT(index, constant_maximum); \
HISTOGRAM_POINTER_USE(&atomic_histograms[index], constant_histogram_name, \
histogram_add_method_invocation, \
histogram_factory_get_invocation); \
} while (0)
//------------------------------------------------------------------------------
// Deprecated histogram macros. Not recommended for current use.
// Legacy name for UMA_HISTOGRAM_COUNTS_1M. Suggest using explicit naming
// and not using this macro going forward.
#define UMA_HISTOGRAM_COUNTS(name, sample) UMA_HISTOGRAM_CUSTOM_COUNTS( \
name, sample, 1, 1000000, 50)
// MB-granularity memory metric. This has a short max (1G).
#define UMA_HISTOGRAM_MEMORY_MB(name, sample) \
UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, 1, 1000, 50)
// For an enum with customized range. In general, sparse histograms should be
// used instead.
// Samples should be one of the std::vector<int> list provided via
// |custom_ranges|. See comments above CustomRanges::FactoryGet about the
// requirement of |custom_ranges|. You can use the helper function
// CustomHistogram::ArrayToCustomRanges to transform a C-style array of valid
// sample values to a std::vector<int>.
#define UMA_HISTOGRAM_CUSTOM_ENUMERATION(name, sample, custom_ranges) \
STATIC_HISTOGRAM_POINTER_BLOCK(name, Add(sample), \
base::CustomHistogram::FactoryGet(name, custom_ranges, \
base::HistogramBase::kUmaTargetedHistogramFlag))
#endif // BASE_METRICS_HISTOGRAM_MACROS_H_