Add user-defined counters. (#262)
* Added user counters, and move use of bytes_processed and items_processed to user counter logic.
Each counter is a string-value pair. The counters were
made available through the State class. Two helper virtual
methods were added to the Fixture class to allow convenient
initialization and termination of the counters: InitState()
and TerminateState(). The reporting of the counters is buggy
and is still a work in progress, to be completed in the next commits.
* fix bad removal of BenchmarkCounters code during the merge
* add myself to AUTHORS/CONTRIBUTORS
* fix printing to std::cout in csv_reporter
* bytes_per_second and items_per_second are now in the UserCounters class
* add user counters to json reporter
* moving bytes_per_second and items_per_second to their old state
* console reporter dealing ok with user counters.
* update unit tests for user counters
* CSVReporter now prints user counters too.
* cleanup user counters
* reverted changes to cmake files which should have gone into later commits
* fixture_test: fix gcc 4.6 compilation
* remove ctor with default argument
see https://github.com/google/benchmark/pull/262#discussion_r72298055
* use (auto-defined) BENCHMARK_HAS_CXX11 instead of BENCHMARK_INITLIST.
https://github.com/google/benchmark/pull/262#discussion_r72298310
* leanify counters API
Discussions:
API complexity: https://github.com/google/benchmark/pull/262#discussion_r72298731
remove std::string dependency (WIP): https://github.com/google/benchmark/pull/262#discussion_r72298142
spacing & alignment: https://github.com/google/benchmark/pull/262#discussion_r72298422
* remove std::string dependency on public API - changed counter name storage to char*
* Counter ctor: use overloads instead of default arguments
discussion:
https://github.com/google/benchmark/pull/262#discussion_r72298055
* Use raw pointers to remove dependency on std::vector from public API .
For more info, see discussion at https://github.com/google/benchmark/pull/262#discussion_r72319678 .
* Move counter implementation from benchmark.cc to counter.cc.
See discussion: https://github.com/google/benchmark/pull/262#discussion_r72298980 .
* Remove unused (commented-out) code.
* Moved thread counters to ThreadStats.
* Counters: fixed copy and move constructors.
* Counter: use an inplace buffer for small names.
* benchmark_test: move counters test out of CXX11 preprocessor conditional.
* Counter: fix VS2013 compilation error in char[] initialization.
* Fix typo.
* Expose counters from State.
See discussion: https://github.com/google/benchmark/pull/262#issuecomment-237156951
* Changed counters interface to map-like.
* Fix printing of user counters in ConsoleReporter.
* Applied clang-format to counter.cc and console_reporter.cc.
Command was `clang-format -style=Google -i counter.cc console_reporter.cc`
I also applied to all other files, but the changes were very
far-reaching so I rolled those back.
* Rename Counter::Flags_e to Counter::Flags
* Fix use of reserved names in Counter and BenchmarkCounters.
* Counter: Fix move ctor bug + change order of members.
* Fixture: remove tentative methods InitState() and TerminateState().
* Update fixture_test to the new Fixture interface.
* BenchmarkCounters: fixed a bug in the move ctor. Remove call to CHECK_LT().
CHECK_LT() was making the size_t lookup take ~double the time of a string lookup!
* BenchmarkCounters: add option to not print zero counters (defaults to false).
* Add test to compare counter storage and access with std::map.
* README: clarify cost of counter access modes.
* move counter access test to an own test.
* BenchmarkCounters: add move Insert()
* Counters access test: add accelerated lookup by name.
* Fix old range syntax.
* Fix missing include of cstdio
* Fix Visual Studio warning
* VS2013 and lower: fix use of snprintf()
* VS2013: fix use of char[] as a member of std::pair<>.
* change counter storage to std::map
* Remove skipZeroCounters logic
* Fix VS compilation error.
* Implemented request changes to PR #262.
* PR #262: More requested changes.
* README: cleanup counter text.
* PR #262: remove clang-format changes for preexisting code
* Complexity+Counters: fix counter flags which were being ignored.
* Document all Counter::Flag members
* fixed loss of counter values
* ConsoleReporter: remove tabular printing of user counters.
* ConsoleReporter: header printing should not be contingent on user counter names.
* Minor white space and alignment fixes.
* cxx03_test + counters: reuse the BM_empty() function.
* user counters: add note to README on how counters are gathered across threads
diff --git a/README.md b/README.md
index 2cfb70b..456b0a6 100644
--- a/README.md
+++ b/README.md
@@ -432,6 +432,65 @@
/* BarTest is now registered */
```
+
+## User-defined counters
+
+You can add your own counters with user-defined names. The example below
+will add columns "Foo", "Bar" and "Baz" in its output:
+
+```c++
+static void UserCountersExample1(benchmark::State& state) {
+ double numFoos = 0, numBars = 0, numBazs = 0;
+ while (state.KeepRunning()) {
+ // ... count Foo,Bar,Baz events
+ }
+ state.counters["Foo"] = numFoos;
+ state.counters["Bar"] = numBars;
+ state.counters["Baz"] = numBazs;
+}
+```
+
+The `state.counters` object is a `std::map` with `std::string` keys
+and `Counter` values. The latter is a `double`-like class, via an implicit
+conversion to `double&`. Thus you can use all of the standard arithmetic
+assignment operators (`=,+=,-=,*=,/=`) to change the value of each counter.
+
+In multithreaded benchmarks, each counter is set on the calling thread only.
+When the benchmark finishes, the counters from each thread will be summed;
+the resulting sum is the value which will be shown for the benchmark.
+
+The `Counter` constructor accepts two parameters: the value as a `double`
+and a bit flag which allows you to show counters as rates and/or as
+per-thread averages:
+
+```c++
+ // sets a simple counter
+ state.counters["Foo"] = numFoos;
+
+ // Set the counter as a rate. It will be presented divided
+ // by the duration of the benchmark.
+ state.counters["FooRate"] = Counter(numFoos, benchmark::Counter::kIsRate);
+
+ // Set the counter as a thread-average quantity. It will
+ // be presented divided by the number of threads.
+ state.counters["FooAvg"] = Counter(numFoos, benchmark::Counter::kAvgThreads);
+
+ // There's also a combined flag:
+ state.counters["FooAvgRate"] = Counter(numFoos,benchmark::Counter::kAvgThreadsRate);
+```
+
+When you're compiling in C++11 mode or later you can use `insert()` with
+`std::initializer_list`:
+
+```c++
+ // With C++11, this can be done:
+ state.counters.insert({{"Foo", numFoos}, {"Bar", numBars}, {"Baz", numBazs}});
+ // ... instead of:
+ state.counters["Foo"] = numFoos;
+ state.counters["Bar"] = numBars;
+ state.counters["Baz"] = numBazs;
+```
+
## Exiting Benchmarks in Error
When errors caused by external influences, such as file I/O and network
@@ -503,7 +562,7 @@
information about the CPU and the date.
The `benchmarks` attribute contains a list of ever benchmark run. Example json
output looks like:
-``` json
+```json
{
"context": {
"date": "2015/03/17-18:40:25",
