1#!/usr/bin/env python 2# Copyright (c) 2012 The Chromium Authors. All rights reserved. 3# Use of this source code is governed by a BSD-style license that can be 4# found in the LICENSE file. 5 6'''Support for formatting a data pack file used for platform agnostic resource 7files. 8''' 9 10import collections 11import exceptions 12import os 13import struct 14import sys 15if __name__ == '__main__': 16 sys.path.append(os.path.join(os.path.dirname(__file__), '../..')) 17 18from grit import util 19from grit.node import include 20from grit.node import message 21from grit.node import structure 22from grit.node import misc 23 24 25PACK_FILE_VERSION = 4 26HEADER_LENGTH = 2 * 4 + 1 # Two uint32s. (file version, number of entries) and 27 # one uint8 (encoding of text resources) 28BINARY, UTF8, UTF16 = range(3) 29 30 31class WrongFileVersion(Exception): 32 pass 33 34 35DataPackContents = collections.namedtuple( 36 'DataPackContents', 'resources encoding') 37 38 39def Format(root, lang='en', output_dir='.'): 40 '''Writes out the data pack file format (platform agnostic resource file).''' 41 data = {} 42 for node in root.ActiveDescendants(): 43 with node: 44 if isinstance(node, (include.IncludeNode, message.MessageNode, 45 structure.StructureNode)): 46 id, value = node.GetDataPackPair(lang, UTF8) 47 if value is not None: 48 data[id] = value 49 return WriteDataPackToString(data, UTF8) 50 51 52def ReadDataPack(input_file): 53 """Reads a data pack file and returns a dictionary.""" 54 data = util.ReadFile(input_file, util.BINARY) 55 original_data = data 56 57 # Read the header. 58 version, num_entries, encoding = struct.unpack("<IIB", data[:HEADER_LENGTH]) 59 if version != PACK_FILE_VERSION: 60 print "Wrong file version in ", input_file 61 raise WrongFileVersion 62 63 resources = {} 64 if num_entries == 0: 65 return DataPackContents(resources, encoding) 66 67 # Read the index and data. 68 data = data[HEADER_LENGTH:] 69 kIndexEntrySize = 2 + 4 # Each entry is a uint16 and a uint32. 70 for _ in range(num_entries): 71 id, offset = struct.unpack("<HI", data[:kIndexEntrySize]) 72 data = data[kIndexEntrySize:] 73 next_id, next_offset = struct.unpack("<HI", data[:kIndexEntrySize]) 74 resources[id] = original_data[offset:next_offset] 75 76 return DataPackContents(resources, encoding) 77 78 79def WriteDataPackToString(resources, encoding): 80 """Write a map of id=>data into a string in the data pack format and return 81 it.""" 82 ids = sorted(resources.keys()) 83 ret = [] 84 85 # Write file header. 86 ret.append(struct.pack("<IIB", PACK_FILE_VERSION, len(ids), encoding)) 87 HEADER_LENGTH = 2 * 4 + 1 # Two uint32s and one uint8. 88 89 # Each entry is a uint16 + a uint32s. We have one extra entry for the last 90 # item. 91 index_length = (len(ids) + 1) * (2 + 4) 92 93 # Write index. 94 data_offset = HEADER_LENGTH + index_length 95 for id in ids: 96 ret.append(struct.pack("<HI", id, data_offset)) 97 data_offset += len(resources[id]) 98 99 ret.append(struct.pack("<HI", 0, data_offset)) 100 101 # Write data. 102 for id in ids: 103 ret.append(resources[id]) 104 return ''.join(ret) 105 106 107def WriteDataPack(resources, output_file, encoding): 108 """Write a map of id=>data into output_file as a data pack.""" 109 content = WriteDataPackToString(resources, encoding) 110 with open(output_file, "wb") as file: 111 file.write(content) 112 113 114def RePack(output_file, input_files): 115 """Write a new data pack to |output_file| based on a list of filenames 116 (|input_files|)""" 117 resources = {} 118 encoding = None 119 for filename in input_files: 120 new_content = ReadDataPack(filename) 121 122 # Make sure we have no dups. 123 duplicate_keys = set(new_content.resources.keys()) & set(resources.keys()) 124 if len(duplicate_keys) != 0: 125 raise exceptions.KeyError("Duplicate keys: " + str(list(duplicate_keys))) 126 127 # Make sure encoding is consistent. 128 if encoding in (None, BINARY): 129 encoding = new_content.encoding 130 elif new_content.encoding not in (BINARY, encoding): 131 raise exceptions.KeyError("Inconsistent encodings: " + 132 str(encoding) + " vs " + 133 str(new_content.encoding)) 134 135 resources.update(new_content.resources) 136 137 # Encoding is 0 for BINARY, 1 for UTF8 and 2 for UTF16 138 if encoding is None: 139 encoding = BINARY 140 WriteDataPack(resources, output_file, encoding) 141 142 143# Temporary hack for external programs that import data_pack. 144# TODO(benrg): Remove this. 145class DataPack(object): 146 pass 147DataPack.ReadDataPack = staticmethod(ReadDataPack) 148DataPack.WriteDataPackToString = staticmethod(WriteDataPackToString) 149DataPack.WriteDataPack = staticmethod(WriteDataPack) 150DataPack.RePack = staticmethod(RePack) 151 152 153def main(): 154 if len(sys.argv) > 1: 155 # When an argument is given, read and explode the file to text 156 # format, for easier diffing. 157 data = ReadDataPack(sys.argv[1]) 158 print data.encoding 159 for (resource_id, text) in data.resources.iteritems(): 160 print "%s: %s" % (resource_id, text) 161 else: 162 # Just write a simple file. 163 data = { 1: "", 4: "this is id 4", 6: "this is id 6", 10: "" } 164 WriteDataPack(data, "datapack1.pak", UTF8) 165 data2 = { 1000: "test", 5: "five" } 166 WriteDataPack(data2, "datapack2.pak", UTF8) 167 print "wrote datapack1 and datapack2 to current directory." 168 169 170if __name__ == '__main__': 171 main() 172