Python library for writing data pack files (see base/data_pack*).

tools/data_pack/DataPack.py

+#!/usr/bin/python

[tony, 2009/01/08 00:44:53]

Nit: this file should be named data_pack.py or something.

+# Copyright (c) 2008 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.
+
+"""A simple utility function to produce data pack files.
+See base/pack_file* for details.
+"""
+
+import struct
+
+version = 1
+
+def WriteDataPack(resources, output_file):
+  """Write a map of id=>data into output_file as a data pack."""
+  ids = sorted(resources.keys())
+  file = open(output_file, "wb")
+
+  # Write file header.
+  file.write(struct.pack("<II", version, len(ids)))
+  header_length = 2 * 4             # Two uint32s.
+
+  index_length = len(ids) * 3 * 4   # Each entry is 3 uint32s.
+
+  # Write index.
+  data_offset = header_length + index_length
+  for id in ids:
+    file.write(struct.pack("<III", id, data_offset, len(resources[id])))
+    data_offset += len(resources[id])
+
+  # Write data.
+  for id in ids:
+    file.write(resources[id])
+
+def main():
+  # Just write a simple file.
+  data = { 1: "", 4: "this is id 4", 6: "this is id 6", 10: "" }

[tony, 2009/01/08 00:44:53]

Maybe include some embedded nulls?

+  WriteDataPack(data, "datapack")
+  print "wrote datapack to current directory."
+
+if __name__ == '__main__':
+  main()