Adding Google benchmarking library.

third_party/google_benchmark/tools/gbench/report.py

Index: third_party/google_benchmark/tools/gbench/report.py
diff --git a/third_party/google_benchmark/tools/gbench/report.py b/third_party/google_benchmark/tools/gbench/report.py
new file mode 100644
index 0000000000000000000000000000000000000000..015d33d9e49fc8319543252b82cbdd51dc78d8e0
--- /dev/null
+++ b/third_party/google_benchmark/tools/gbench/report.py
@@ -0,0 +1,146 @@
+"""report.py - Utilities for reporting statistics about benchmark results
+"""
+import os
+
+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_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')
+
+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 generate_difference_report(json1, json2, use_color=True):
+    """
+    Calculate and report the difference between each test of two benchmarks
+    runs specified as 'json1' and 'json2'.
+    """
+    first_col_width = find_longest_name(json1['benchmarks']) + 5
+    def find_test(name):
+        for b in json2['benchmarks']:
+            if b['name'] == name:
+                return b
+        return None
+    first_line = "{:<{}s}     Time           CPU           Old           New".format(
+        'Benchmark', first_col_width)
+    output_strs = [first_line, '-' * len(first_line)]
+
+    gen = (bn for bn in json1['benchmarks'] if 'real_time' in bn and 'cpu_time' in bn)
+    for bn in gen:
+        other_bench = find_test(bn['name'])
+        if not other_bench:
+            continue
+
+        def get_color(res):
+            if res > 0.05:
+                return BC_FAIL
+            elif res > -0.07:
+                return BC_WHITE
+            else:
+                return BC_CYAN
+        fmt_str = "{}{:<{}s}{endc}{}{:+9.2f}{endc}{}{:+14.2f}{endc}{:14d}{:14d}"
+        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['cpu_time'], other_bench['cpu_time'],
+            endc=BC_ENDC)]
+    return output_strs
+
+###############################################################################
+# Unit tests
+
+import unittest
+
+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', '+0.00', '+0.00', '10', '10'],
+            ['BM_2xFaster', '-0.50', '-0.50', '50', '25'],
+            ['BM_2xSlower', '+1.00', '+1.00', '50', '100'],
+            ['BM_10PercentFaster', '-0.10', '-0.10', '100', '90'],
+            ['BM_10PercentSlower', '+0.10', '+0.10', '100', '110'],
+            ['BM_100xSlower', '+99.00', '+99.00', '100', '10000'],
+            ['BM_100xFaster', '-0.99', '-0.99', '10000', '100'],
+        ]
+        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".join(output_lines_with_header))
+        self.assertEqual(len(output_lines), len(expect_lines))
+        for i in xrange(0, len(output_lines)):
+            parts = [x for x in output_lines[i].split(' ') if x]
+            self.assertEqual(len(parts), 5)
+            self.assertEqual(parts, expect_lines[i])
+
+
+if __name__ == '__main__':
+    unittest.main()