1 #!/usr/bin/env python 2 # Copyright 2014 The PDFium 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 """Expands a hand-written PDF testcase (template) into a valid PDF file. 7 8 There are several places in a PDF file where byte-offsets are required. This 9 script replaces {{name}}-style variables in the input with calculated results 10 11 {{header}} - expands to the header comment required for PDF files. 12 {{xref}} - expands to a generated xref table, noting the offset. 13 {{startxref} - expands to a startxref directive followed by correct offset. 14 {{object x y}} - expands to |x y obj| declaration, noting the offset.""" 15 16 import optparse 17 import os 18 import re 19 import sys 20 21 class TemplateProcessor: 22 HEADER_TOKEN = '{{header}}' 23 HEADER_REPLACEMENT = '%PDF-1.7\n%\xa0\xf2\xa4\xf4' 24 25 XREF_TOKEN = '{{xref}}' 26 XREF_REPLACEMENT = 'xref\n%d %d\n' 27 28 # XREF rows must be exactly 20 bytes - space required. 29 XREF_REPLACEMENT_N = '%010d %05d n \n' 30 XREF_REPLACEMENT_F = '0000000000 65535 f \n' 31 32 STARTXREF_TOKEN= '{{startxref}}' 33 STARTXREF_REPLACEMENT = 'startxref\n%d' 34 35 OBJECT_PATTERN = r'\{\{object\s+(\d+)\s+(\d+)\}\}' 36 OBJECT_REPLACEMENT = r'\1 \2 obj' 37 38 def __init__(self): 39 self.offset = 0 40 self.xref_offset = 0 41 self.max_object_number = 0 42 self.objects = { } 43 44 def insert_xref_entry(self, object_number, generation_number): 45 self.objects[object_number] = (self.offset, generation_number) 46 self.max_object_number = max(self.max_object_number, object_number) 47 48 def generate_xref_table(self): 49 result = self.XREF_REPLACEMENT % (0, self.max_object_number + 1) 50 for i in range(0, self.max_object_number + 1): 51 if i in self.objects: 52 result += self.XREF_REPLACEMENT_N % self.objects[i] 53 else: 54 result += self.XREF_REPLACEMENT_F 55 return result 56 57 def process_line(self, line): 58 if self.HEADER_TOKEN in line: 59 line = line.replace(self.HEADER_TOKEN, self.HEADER_REPLACEMENT) 60 if self.XREF_TOKEN in line: 61 self.xref_offset = self.offset 62 line = self.generate_xref_table() 63 if self.STARTXREF_TOKEN in line: 64 replacement = self.STARTXREF_REPLACEMENT % self.xref_offset 65 line = line.replace(self.STARTXREF_TOKEN, replacement) 66 match = re.match(self.OBJECT_PATTERN, line) 67 if match: 68 self.insert_xref_entry(int(match.group(1)), int(match.group(2))) 69 line = re.sub(self.OBJECT_PATTERN, self.OBJECT_REPLACEMENT, line) 70 self.offset += len(line) 71 return line 72 73 74 def expand_file(input_path, output_path): 75 processor = TemplateProcessor() 76 try: 77 with open(input_path, 'rb') as infile: 78 with open(output_path, 'wb') as outfile: 79 for line in infile: 80 outfile.write(processor.process_line(line)) 81 except IOError: 82 print >> sys.stderr, 'failed to process %s' % input_path 83 84 85 def main(): 86 parser = optparse.OptionParser() 87 parser.add_option('--output-dir', default='') 88 options, args = parser.parse_args() 89 for testcase_path in args: 90 testcase_filename = os.path.basename(testcase_path) 91 testcase_root, _ = os.path.splitext(testcase_filename) 92 output_dir = os.path.dirname(testcase_path) 93 if options.output_dir: 94 output_dir = options.output_dir 95 output_path = os.path.join(output_dir, testcase_root + '.pdf') 96 expand_file(testcase_path, output_path) 97 return 0 98 99 100 if __name__ == '__main__': 101 sys.exit(main()) 102
