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/util.py b/tools/gbench/util.py
new file mode 100644
index 0000000..1f8e8e2
--- /dev/null
+++ b/tools/gbench/util.py
@@ -0,0 +1,164 @@
+"""util.py - General utilities for running, loading, and processing benchmarks
+"""
+import json
+import os
+import tempfile
+import subprocess
+import sys
+
+# Input file type enumeration
+IT_Invalid = 0
+IT_JSON = 1
+IT_Executable = 2
+
+_num_magic_bytes = 2 if sys.platform.startswith('win') else 4
+
+
+def is_executable_file(filename):
+ """
+ Return 'True' if 'filename' names a valid file which is likely
+ an executable. A file is considered an executable if it starts with the
+ magic bytes for a EXE, Mach O, or ELF file.
+ """
+ if not os.path.isfile(filename):
+ return False
+ with open(filename, mode='rb') as f:
+ magic_bytes = f.read(_num_magic_bytes)
+ if sys.platform == 'darwin':
+ return magic_bytes in [
+ b'\xfe\xed\xfa\xce', # MH_MAGIC
+ b'\xce\xfa\xed\xfe', # MH_CIGAM
+ b'\xfe\xed\xfa\xcf', # MH_MAGIC_64
+ b'\xcf\xfa\xed\xfe', # MH_CIGAM_64
+ b'\xca\xfe\xba\xbe', # FAT_MAGIC
+ b'\xbe\xba\xfe\xca' # FAT_CIGAM
+ ]
+ elif sys.platform.startswith('win'):
+ return magic_bytes == b'MZ'
+ else:
+ return magic_bytes == b'\x7FELF'
+
+
+def is_json_file(filename):
+ """
+ Returns 'True' if 'filename' names a valid JSON output file.
+ 'False' otherwise.
+ """
+ try:
+ with open(filename, 'r') as f:
+ json.load(f)
+ return True
+ except BaseException:
+ pass
+ return False
+
+
+def classify_input_file(filename):
+ """
+ Return a tuple (type, msg) where 'type' specifies the classified type
+ of 'filename'. If 'type' is 'IT_Invalid' then 'msg' is a human readable
+ string represeting the error.
+ """
+ ftype = IT_Invalid
+ err_msg = None
+ if not os.path.exists(filename):
+ err_msg = "'%s' does not exist" % filename
+ elif not os.path.isfile(filename):
+ err_msg = "'%s' does not name a file" % filename
+ elif is_executable_file(filename):
+ ftype = IT_Executable
+ elif is_json_file(filename):
+ ftype = IT_JSON
+ else:
+ err_msg = "'%s' does not name a valid benchmark executable or JSON file" % filename
+ return ftype, err_msg
+
+
+def check_input_file(filename):
+ """
+ Classify the file named by 'filename' and return the classification.
+ If the file is classified as 'IT_Invalid' print an error message and exit
+ the program.
+ """
+ ftype, msg = classify_input_file(filename)
+ if ftype == IT_Invalid:
+ print("Invalid input file: %s" % msg)
+ sys.exit(1)
+ return ftype
+
+
+def find_benchmark_flag(prefix, benchmark_flags):
+ """
+ Search the specified list of flags for a flag matching `<prefix><arg>` and
+ if it is found return the arg it specifies. If specified more than once the
+ last value is returned. If the flag is not found None is returned.
+ """
+ assert prefix.startswith('--') and prefix.endswith('=')
+ result = None
+ for f in benchmark_flags:
+ if f.startswith(prefix):
+ result = f[len(prefix):]
+ return result
+
+
+def remove_benchmark_flags(prefix, benchmark_flags):
+ """
+ Return a new list containing the specified benchmark_flags except those
+ with the specified prefix.
+ """
+ assert prefix.startswith('--') and prefix.endswith('=')
+ return [f for f in benchmark_flags if not f.startswith(prefix)]
+
+
+def load_benchmark_results(fname):
+ """
+ Read benchmark output from a file and return the JSON object.
+ REQUIRES: 'fname' names a file containing JSON benchmark output.
+ """
+ with open(fname, 'r') as f:
+ return json.load(f)
+
+
+def run_benchmark(exe_name, benchmark_flags):
+ """
+ Run a benchmark specified by 'exe_name' with the specified
+ 'benchmark_flags'. The benchmark is run directly as a subprocess to preserve
+ real time console output.
+ RETURNS: A JSON object representing the benchmark output
+ """
+ output_name = find_benchmark_flag('--benchmark_out=',
+ benchmark_flags)
+ is_temp_output = False
+ if output_name is None:
+ is_temp_output = True
+ thandle, output_name = tempfile.mkstemp()
+ os.close(thandle)
+ benchmark_flags = list(benchmark_flags) + \
+ ['--benchmark_out=%s' % output_name]
+
+ cmd = [exe_name] + benchmark_flags
+ print("RUNNING: %s" % ' '.join(cmd))
+ exitCode = subprocess.call(cmd)
+ if exitCode != 0:
+ print('TEST FAILED...')
+ sys.exit(exitCode)
+ json_res = load_benchmark_results(output_name)
+ if is_temp_output:
+ os.unlink(output_name)
+ return json_res
+
+
+def run_or_load_benchmark(filename, benchmark_flags):
+ """
+ Get the results for a specified benchmark. If 'filename' specifies
+ an executable benchmark then the results are generated by running the
+ benchmark. Otherwise 'filename' must name a valid JSON output file,
+ which is loaded and the result returned.
+ """
+ ftype = check_input_file(filename)
+ if ftype == IT_JSON:
+ return load_benchmark_results(filename)
+ elif ftype == IT_Executable:
+ return run_benchmark(filename, benchmark_flags)
+ else:
+ assert False # This branch is unreachable