Squashed 'third_party/google-benchmark/' content from commit 785e2c3

Change-Id: Iaaca5eca89f717081452e643a233e86425b03e89
git-subtree-dir: third_party/google-benchmark
git-subtree-split: 785e2c3158589e8ef48c59ba80e48d76bdbd8902
diff --git a/tools/gbench/report.py b/tools/gbench/report.py
new file mode 100644
index 0000000..5085b93
--- /dev/null
+++ b/tools/gbench/report.py
@@ -0,0 +1,522 @@
+import unittest
+"""report.py - Utilities for reporting statistics about benchmark results
+"""
+import os
+import re
+import copy
+
+from scipy.stats import mannwhitneyu
+
+
+class BenchmarkColor(object):
+    def __init__(self, name, code):
+        self.name = name
+        self.code = code
+
+    def __repr__(self):
+        return '%s%r' % (self.__class__.__name__,
+                         (self.name, self.code))
+
+    def __format__(self, format):
+        return self.code
+
+
+# Benchmark Colors Enumeration
+BC_NONE = BenchmarkColor('NONE', '')
+BC_MAGENTA = BenchmarkColor('MAGENTA', '\033[95m')
+BC_CYAN = BenchmarkColor('CYAN', '\033[96m')
+BC_OKBLUE = BenchmarkColor('OKBLUE', '\033[94m')
+BC_OKGREEN = BenchmarkColor('OKGREEN', '\033[32m')
+BC_HEADER = BenchmarkColor('HEADER', '\033[92m')
+BC_WARNING = BenchmarkColor('WARNING', '\033[93m')
+BC_WHITE = BenchmarkColor('WHITE', '\033[97m')
+BC_FAIL = BenchmarkColor('FAIL', '\033[91m')
+BC_ENDC = BenchmarkColor('ENDC', '\033[0m')
+BC_BOLD = BenchmarkColor('BOLD', '\033[1m')
+BC_UNDERLINE = BenchmarkColor('UNDERLINE', '\033[4m')
+
+UTEST_MIN_REPETITIONS = 2
+UTEST_OPTIMAL_REPETITIONS = 9  # Lowest reasonable number, More is better.
+UTEST_COL_NAME = "_pvalue"
+
+
+def color_format(use_color, fmt_str, *args, **kwargs):
+    """
+    Return the result of 'fmt_str.format(*args, **kwargs)' after transforming
+    'args' and 'kwargs' according to the value of 'use_color'. If 'use_color'
+    is False then all color codes in 'args' and 'kwargs' are replaced with
+    the empty string.
+    """
+    assert use_color is True or use_color is False
+    if not use_color:
+        args = [arg if not isinstance(arg, BenchmarkColor) else BC_NONE
+                for arg in args]
+        kwargs = {key: arg if not isinstance(arg, BenchmarkColor) else BC_NONE
+                  for key, arg in kwargs.items()}
+    return fmt_str.format(*args, **kwargs)
+
+
+def find_longest_name(benchmark_list):
+    """
+    Return the length of the longest benchmark name in a given list of
+    benchmark JSON objects
+    """
+    longest_name = 1
+    for bc in benchmark_list:
+        if len(bc['name']) > longest_name:
+            longest_name = len(bc['name'])
+    return longest_name
+
+
+def calculate_change(old_val, new_val):
+    """
+    Return a float representing the decimal change between old_val and new_val.
+    """
+    if old_val == 0 and new_val == 0:
+        return 0.0
+    if old_val == 0:
+        return float(new_val - old_val) / (float(old_val + new_val) / 2)
+    return float(new_val - old_val) / abs(old_val)
+
+
+def filter_benchmark(json_orig, family, replacement=""):
+    """
+    Apply a filter to the json, and only leave the 'family' of benchmarks.
+    """
+    regex = re.compile(family)
+    filtered = {}
+    filtered['benchmarks'] = []
+    for be in json_orig['benchmarks']:
+        if not regex.search(be['name']):
+            continue
+        filteredbench = copy.deepcopy(be)  # Do NOT modify the old name!
+        filteredbench['name'] = regex.sub(replacement, filteredbench['name'])
+        filtered['benchmarks'].append(filteredbench)
+    return filtered
+
+
+def get_unique_benchmark_names(json):
+    """
+    While *keeping* the order, give all the unique 'names' used for benchmarks.
+    """
+    seen = set()
+    uniqued = [x['name'] for x in json['benchmarks']
+               if x['name'] not in seen and
+               (seen.add(x['name']) or True)]
+    return uniqued
+
+
+def intersect(list1, list2):
+    """
+    Given two lists, get a new list consisting of the elements only contained
+    in *both of the input lists*, while preserving the ordering.
+    """
+    return [x for x in list1 if x in list2]
+
+
+def partition_benchmarks(json1, json2):
+    """
+    While preserving the ordering, find benchmarks with the same names in
+    both of the inputs, and group them.
+    (i.e. partition/filter into groups with common name)
+    """
+    json1_unique_names = get_unique_benchmark_names(json1)
+    json2_unique_names = get_unique_benchmark_names(json2)
+    names = intersect(json1_unique_names, json2_unique_names)
+    partitions = []
+    for name in names:
+        # Pick the time unit from the first entry of the lhs benchmark.
+        time_unit = (x['time_unit']
+                     for x in json1['benchmarks'] if x['name'] == name).next()
+        # Filter by name and time unit.
+        lhs = [x for x in json1['benchmarks'] if x['name'] == name and
+               x['time_unit'] == time_unit]
+        rhs = [x for x in json2['benchmarks'] if x['name'] == name and
+               x['time_unit'] == time_unit]
+        partitions.append([lhs, rhs])
+    return partitions
+
+
+def extract_field(partition, field_name):
+    # The count of elements may be different. We want *all* of them.
+    lhs = [x[field_name] for x in partition[0]]
+    rhs = [x[field_name] for x in partition[1]]
+    return [lhs, rhs]
+
+
+def print_utest(partition, utest_alpha, first_col_width, use_color=True):
+    timings_time = extract_field(partition, 'real_time')
+    timings_cpu = extract_field(partition, 'cpu_time')
+
+    min_rep_cnt = min(len(timings_time[0]),
+                      len(timings_time[1]),
+                      len(timings_cpu[0]),
+                      len(timings_cpu[1]))
+
+    # Does *everything* has at least UTEST_MIN_REPETITIONS repetitions?
+    if min_rep_cnt < UTEST_MIN_REPETITIONS:
+        return []
+
+    def get_utest_color(pval):
+        return BC_FAIL if pval >= utest_alpha else BC_OKGREEN
+
+    time_pvalue = mannwhitneyu(
+        timings_time[0], timings_time[1], alternative='two-sided').pvalue
+    cpu_pvalue = mannwhitneyu(
+        timings_cpu[0], timings_cpu[1], alternative='two-sided').pvalue
+
+    dsc = "U Test, Repetitions: {} vs {}".format(
+        len(timings_cpu[0]), len(timings_cpu[1]))
+    dsc_color = BC_OKGREEN
+
+    if min_rep_cnt < UTEST_OPTIMAL_REPETITIONS:
+        dsc_color = BC_WARNING
+        dsc += ". WARNING: Results unreliable! {}+ repetitions recommended.".format(
+            UTEST_OPTIMAL_REPETITIONS)
+
+    special_str = "{}{:<{}s}{endc}{}{:16.4f}{endc}{}{:16.4f}{endc}{}      {}"
+
+    last_name = partition[0][0]['name']
+    return [color_format(use_color,
+                         special_str,
+                         BC_HEADER,
+                         "{}{}".format(last_name, UTEST_COL_NAME),
+                         first_col_width,
+                         get_utest_color(time_pvalue), time_pvalue,
+                         get_utest_color(cpu_pvalue), cpu_pvalue,
+                         dsc_color, dsc,
+                         endc=BC_ENDC)]
+
+
+def generate_difference_report(
+        json1,
+        json2,
+        display_aggregates_only=False,
+        utest=False,
+        utest_alpha=0.05,
+        use_color=True):
+    """
+    Calculate and report the difference between each test of two benchmarks
+    runs specified as 'json1' and 'json2'.
+    """
+    assert utest is True or utest is False
+    first_col_width = find_longest_name(json1['benchmarks'])
+
+    def find_test(name):
+        for b in json2['benchmarks']:
+            if b['name'] == name:
+                return b
+        return None
+
+    first_col_width = max(
+        first_col_width,
+        len('Benchmark'))
+    first_col_width += len(UTEST_COL_NAME)
+    first_line = "{:<{}s}Time             CPU      Time Old      Time New       CPU Old       CPU New".format(
+        'Benchmark', 12 + first_col_width)
+    output_strs = [first_line, '-' * len(first_line)]
+
+    partitions = partition_benchmarks(json1, json2)
+    for partition in partitions:
+        # Careful, we may have different repetition count.
+        for i in range(min(len(partition[0]), len(partition[1]))):
+            bn = partition[0][i]
+            other_bench = partition[1][i]
+
+            # *If* we were asked to only display aggregates,
+            # and if it is non-aggregate, then skip it.
+            if display_aggregates_only and 'run_type' in bn and 'run_type' in other_bench:
+                assert bn['run_type'] == other_bench['run_type']
+                if bn['run_type'] != 'aggregate':
+                    continue
+
+            fmt_str = "{}{:<{}s}{endc}{}{:+16.4f}{endc}{}{:+16.4f}{endc}{:14.0f}{:14.0f}{endc}{:14.0f}{:14.0f}"
+
+            def get_color(res):
+                if res > 0.05:
+                    return BC_FAIL
+                elif res > -0.07:
+                    return BC_WHITE
+                else:
+                    return BC_CYAN
+
+            tres = calculate_change(bn['real_time'], other_bench['real_time'])
+            cpures = calculate_change(bn['cpu_time'], other_bench['cpu_time'])
+            output_strs += [color_format(use_color,
+                                         fmt_str,
+                                         BC_HEADER,
+                                         bn['name'],
+                                         first_col_width,
+                                         get_color(tres),
+                                         tres,
+                                         get_color(cpures),
+                                         cpures,
+                                         bn['real_time'],
+                                         other_bench['real_time'],
+                                         bn['cpu_time'],
+                                         other_bench['cpu_time'],
+                                         endc=BC_ENDC)]
+
+        # After processing the whole partition, if requested, do the U test.
+        if utest:
+            output_strs += print_utest(partition,
+                                       utest_alpha=utest_alpha,
+                                       first_col_width=first_col_width,
+                                       use_color=use_color)
+
+    return output_strs
+
+
+###############################################################################
+# Unit tests
+
+
+class TestGetUniqueBenchmarkNames(unittest.TestCase):
+    def load_results(self):
+        import json
+        testInputs = os.path.join(
+            os.path.dirname(
+                os.path.realpath(__file__)),
+            'Inputs')
+        testOutput = os.path.join(testInputs, 'test3_run0.json')
+        with open(testOutput, 'r') as f:
+            json = json.load(f)
+        return json
+
+    def test_basic(self):
+        expect_lines = [
+            'BM_One',
+            'BM_Two',
+            'short',  # These two are not sorted
+            'medium',  # These two are not sorted
+        ]
+        json = self.load_results()
+        output_lines = get_unique_benchmark_names(json)
+        print("\n")
+        print("\n".join(output_lines))
+        self.assertEqual(len(output_lines), len(expect_lines))
+        for i in range(0, len(output_lines)):
+            self.assertEqual(expect_lines[i], output_lines[i])
+
+
+class TestReportDifference(unittest.TestCase):
+    def load_results(self):
+        import json
+        testInputs = os.path.join(
+            os.path.dirname(
+                os.path.realpath(__file__)),
+            'Inputs')
+        testOutput1 = os.path.join(testInputs, 'test1_run1.json')
+        testOutput2 = os.path.join(testInputs, 'test1_run2.json')
+        with open(testOutput1, 'r') as f:
+            json1 = json.load(f)
+        with open(testOutput2, 'r') as f:
+            json2 = json.load(f)
+        return json1, json2
+
+    def test_basic(self):
+        expect_lines = [
+            ['BM_SameTimes', '+0.0000', '+0.0000', '10', '10', '10', '10'],
+            ['BM_2xFaster', '-0.5000', '-0.5000', '50', '25', '50', '25'],
+            ['BM_2xSlower', '+1.0000', '+1.0000', '50', '100', '50', '100'],
+            ['BM_1PercentFaster', '-0.0100', '-0.0100', '100', '99', '100', '99'],
+            ['BM_1PercentSlower', '+0.0100', '+0.0100', '100', '101', '100', '101'],
+            ['BM_10PercentFaster', '-0.1000', '-0.1000', '100', '90', '100', '90'],
+            ['BM_10PercentSlower', '+0.1000', '+0.1000', '100', '110', '100', '110'],
+            ['BM_100xSlower', '+99.0000', '+99.0000',
+                '100', '10000', '100', '10000'],
+            ['BM_100xFaster', '-0.9900', '-0.9900',
+                '10000', '100', '10000', '100'],
+            ['BM_10PercentCPUToTime', '+0.1000',
+                '-0.1000', '100', '110', '100', '90'],
+            ['BM_ThirdFaster', '-0.3333', '-0.3334', '100', '67', '100', '67'],
+            ['BM_BadTimeUnit', '-0.9000', '+0.2000', '0', '0', '0', '1'],
+        ]
+        json1, json2 = self.load_results()
+        output_lines_with_header = generate_difference_report(
+            json1, json2, use_color=False)
+        output_lines = output_lines_with_header[2:]
+        print("\n")
+        print("\n".join(output_lines_with_header))
+        self.assertEqual(len(output_lines), len(expect_lines))
+        for i in range(0, len(output_lines)):
+            parts = [x for x in output_lines[i].split(' ') if x]
+            self.assertEqual(len(parts), 7)
+            self.assertEqual(expect_lines[i], parts)
+
+
+class TestReportDifferenceBetweenFamilies(unittest.TestCase):
+    def load_result(self):
+        import json
+        testInputs = os.path.join(
+            os.path.dirname(
+                os.path.realpath(__file__)),
+            'Inputs')
+        testOutput = os.path.join(testInputs, 'test2_run.json')
+        with open(testOutput, 'r') as f:
+            json = json.load(f)
+        return json
+
+    def test_basic(self):
+        expect_lines = [
+            ['.', '-0.5000', '-0.5000', '10', '5', '10', '5'],
+            ['./4', '-0.5000', '-0.5000', '40', '20', '40', '20'],
+            ['Prefix/.', '-0.5000', '-0.5000', '20', '10', '20', '10'],
+            ['Prefix/./3', '-0.5000', '-0.5000', '30', '15', '30', '15'],
+        ]
+        json = self.load_result()
+        json1 = filter_benchmark(json, "BM_Z.ro", ".")
+        json2 = filter_benchmark(json, "BM_O.e", ".")
+        output_lines_with_header = generate_difference_report(
+            json1, json2, use_color=False)
+        output_lines = output_lines_with_header[2:]
+        print("\n")
+        print("\n".join(output_lines_with_header))
+        self.assertEqual(len(output_lines), len(expect_lines))
+        for i in range(0, len(output_lines)):
+            parts = [x for x in output_lines[i].split(' ') if x]
+            self.assertEqual(len(parts), 7)
+            self.assertEqual(expect_lines[i], parts)
+
+
+class TestReportDifferenceWithUTest(unittest.TestCase):
+    def load_results(self):
+        import json
+        testInputs = os.path.join(
+            os.path.dirname(
+                os.path.realpath(__file__)),
+            'Inputs')
+        testOutput1 = os.path.join(testInputs, 'test3_run0.json')
+        testOutput2 = os.path.join(testInputs, 'test3_run1.json')
+        with open(testOutput1, 'r') as f:
+            json1 = json.load(f)
+        with open(testOutput2, 'r') as f:
+            json2 = json.load(f)
+        return json1, json2
+
+    def test_utest(self):
+        expect_lines = []
+        expect_lines = [
+            ['BM_One', '-0.1000', '+0.1000', '10', '9', '100', '110'],
+            ['BM_Two', '+0.1111', '-0.0111', '9', '10', '90', '89'],
+            ['BM_Two', '-0.1250', '-0.1628', '8', '7', '86', '72'],
+            ['BM_Two_pvalue',
+             '0.6985',
+             '0.6985',
+             'U',
+             'Test,',
+             'Repetitions:',
+             '2',
+             'vs',
+             '2.',
+             'WARNING:',
+             'Results',
+             'unreliable!',
+             '9+',
+             'repetitions',
+             'recommended.'],
+            ['short', '-0.1250', '-0.0625', '8', '7', '80', '75'],
+            ['short', '-0.4325', '-0.1351', '8', '5', '77', '67'],
+            ['short_pvalue',
+             '0.7671',
+             '0.1489',
+             'U',
+             'Test,',
+             'Repetitions:',
+             '2',
+             'vs',
+             '3.',
+             'WARNING:',
+             'Results',
+             'unreliable!',
+             '9+',
+             'repetitions',
+             'recommended.'],
+            ['medium', '-0.3750', '-0.3375', '8', '5', '80', '53'],
+        ]
+        json1, json2 = self.load_results()
+        output_lines_with_header = generate_difference_report(
+            json1, json2, utest=True, utest_alpha=0.05, use_color=False)
+        output_lines = output_lines_with_header[2:]
+        print("\n")
+        print("\n".join(output_lines_with_header))
+        self.assertEqual(len(output_lines), len(expect_lines))
+        for i in range(0, len(output_lines)):
+            parts = [x for x in output_lines[i].split(' ') if x]
+            self.assertEqual(expect_lines[i], parts)
+
+
+class TestReportDifferenceWithUTestWhileDisplayingAggregatesOnly(
+        unittest.TestCase):
+    def load_results(self):
+        import json
+        testInputs = os.path.join(
+            os.path.dirname(
+                os.path.realpath(__file__)),
+            'Inputs')
+        testOutput1 = os.path.join(testInputs, 'test3_run0.json')
+        testOutput2 = os.path.join(testInputs, 'test3_run1.json')
+        with open(testOutput1, 'r') as f:
+            json1 = json.load(f)
+        with open(testOutput2, 'r') as f:
+            json2 = json.load(f)
+        return json1, json2
+
+    def test_utest(self):
+        expect_lines = []
+        expect_lines = [
+            ['BM_One', '-0.1000', '+0.1000', '10', '9', '100', '110'],
+            ['BM_Two', '+0.1111', '-0.0111', '9', '10', '90', '89'],
+            ['BM_Two', '-0.1250', '-0.1628', '8', '7', '86', '72'],
+            ['BM_Two_pvalue',
+             '0.6985',
+             '0.6985',
+             'U',
+             'Test,',
+             'Repetitions:',
+             '2',
+             'vs',
+             '2.',
+             'WARNING:',
+             'Results',
+             'unreliable!',
+             '9+',
+             'repetitions',
+             'recommended.'],
+            ['short', '-0.1250', '-0.0625', '8', '7', '80', '75'],
+            ['short', '-0.4325', '-0.1351', '8', '5', '77', '67'],
+            ['short_pvalue',
+             '0.7671',
+             '0.1489',
+             'U',
+             'Test,',
+             'Repetitions:',
+             '2',
+             'vs',
+             '3.',
+             'WARNING:',
+             'Results',
+             'unreliable!',
+             '9+',
+             'repetitions',
+             'recommended.'],
+        ]
+        json1, json2 = self.load_results()
+        output_lines_with_header = generate_difference_report(
+            json1, json2, display_aggregates_only=True,
+            utest=True, utest_alpha=0.05, use_color=False)
+        output_lines = output_lines_with_header[2:]
+        print("\n")
+        print("\n".join(output_lines_with_header))
+        self.assertEqual(len(output_lines), len(expect_lines))
+        for i in range(0, len(output_lines)):
+            parts = [x for x in output_lines[i].split(' ') if x]
+            self.assertEqual(expect_lines[i], parts)
+
+
+if __name__ == '__main__':
+    unittest.main()
+
+# vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4
+# kate: tab-width: 4; replace-tabs on; indent-width 4; tab-indents: off;
+# kate: indent-mode python; remove-trailing-spaces modified;