[gin] Fingerprint the V8 snapshot files on Windows and verify before loading the snapshot.

gin/fingerprint/fingerprint_v8_snapshot.py

Index: gin/fingerprint/fingerprint_v8_snapshot.py
diff --git a/gin/fingerprint/fingerprint_v8_snapshot.py b/gin/fingerprint/fingerprint_v8_snapshot.py
new file mode 100755
index 0000000000000000000000000000000000000000..11da9e613917c6e57a4917ed2cd920359b048eba
--- /dev/null
+++ b/gin/fingerprint/fingerprint_v8_snapshot.py
@@ -0,0 +1,86 @@
+#!/usr/bin/env python
+#
+# Copyright 2015 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.
+
+"""Fingerprints the V8 snapshot blob files.
+
+Constructs a SHA256 fingerprint of the V8 natives and snapshot blob files and
+creates a .cc file which includes these fingerprint as variables.
+"""
+
+import hashlib
+import optparse
+import os
+import sys
+
+_HEADER = """// Copyright (c) 2015 The Chromium Authors. All rights reserved.

[grt (UTC plus 2), 2015/01/07 19:27:18]

nit: no "(c)" in new copyright notices
(http://www.chromium.org/developers/coding-style#TOC-File-headers)

[rmcilroy, 2015/01/08 15:05:35]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file was generated by fingerprint_v8_snapshot.py.
+
+namespace gin {
+"""
+
+_FOOTER = """
+}  // namespace gin
+"""
+
+
+def FingerprintFile(file_path):
+  input_file = open(file_path, 'rb')
+  sha256 = hashlib.sha256()
+  while True:
+    block = input_file.read(sha256.block_size)
+    if not block:
+      break
+    sha256.update(block)
+  return sha256.digest()
+
+
+def WriteFingerprint(output_file, variable_name, fingerprint):
+  output_file.write('\nextern const unsigned char %s[] = { ' % variable_name)
+  for byte in fingerprint:
+    output_file.write(str(ord(byte)) + ', ')
+  output_file.write('};\n')
+
+
+def WriteOutputFile(natives_fingerprint,
+                    snapshot_fingerprint,
+                    output_file_path):
+  output_dir_path = os.path.dirname(output_file_path)
+  if not os.path.exists(output_dir_path):
+    os.makedirs(output_dir_path)
+  output_file = open(output_file_path, 'w')
+
+  output_file.write(_HEADER)
+  WriteFingerprint(output_file, 'g_natives_fingerprint', natives_fingerprint)
+  output_file.write('\n')
+  WriteFingerprint(output_file, 'g_snapshot_fingerprint', snapshot_fingerprint)
+  output_file.write(_FOOTER)
+
+
+def main():
+  parser = optparse.OptionParser()
+
+  parser.add_option('--snapshot_file',
+                    help='The input V8 snapshot blob file path.')
+  parser.add_option('--natives_file',
+                    help='The input V8 natives blob file path.')
+  parser.add_option('--output_file',
+                    help='The path for the output cc file which will be write.')
+
+  options, _ = parser.parse_args()
+
+  natives_fingerprint = FingerprintFile(options.natives_file)
+  snapshot_fingerprint = FingerprintFile(options.snapshot_file)
+  WriteOutputFile(
+      natives_fingerprint, snapshot_fingerprint, options.output_file)
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())