blob: 808c0bb555653c3cb26a4fb20a5df52cc2712ba2 [file] [log] [blame]
#!/usr/bin/env python
# Copyright 2014 The PDFium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Expands a hand-written PDF testcase (template) into a valid PDF file.
There are several places in a PDF file where byte-offsets are required. This
script replaces {{name}}-style variables in the input with calculated results
{{include path/to/file}} - inserts file's contents into stream.
{{header}} - expands to the header comment required for PDF files.
{{xref}} - expands to a generated xref table, noting the offset.
{{trailer}} - expands to a standard trailer with "1 0 R" as the /Root.
{{trailersize}} - expands to |/Size n|, to be used in non-standard trailers.
{{startxref} - expands to a startxref directive followed by correct offset.
{{object x y}} - expands to |x y obj| declaration, noting the offset.
{{streamlen}} - expands to |/Length n|.
"""
import cStringIO
import optparse
import os
import re
import sys
# Line Endings.
WINDOWS_LINE_ENDING = b'\r\n'
UNIX_LINE_ENDING = b'\n'
# List of extensions whose line endings should be modified after parsing.
EXTENSION_OVERRIDE_LINE_ENDINGS = [
'.js',
'.fragment',
'.in',
'.xml',
]
class StreamLenState:
START = 1
FIND_STREAM = 2
FIND_ENDSTREAM = 3
class TemplateProcessor:
HEADER_TOKEN = '{{header}}'
HEADER_REPLACEMENT = '%PDF-1.7\n%\xa0\xf2\xa4\xf4'
XREF_TOKEN = '{{xref}}'
XREF_REPLACEMENT = 'xref\n%d %d\n'
XREF_REPLACEMENT_N = '%010d %05d n \n'
XREF_REPLACEMENT_F = '0000000000 65535 f \n'
# XREF rows must be exactly 20 bytes - space required.
assert len(XREF_REPLACEMENT_F) == 20
TRAILER_TOKEN = '{{trailer}}'
TRAILER_REPLACEMENT = 'trailer <<\n /Root 1 0 R\n /Size %d\n>>'
TRAILERSIZE_TOKEN = '{{trailersize}}'
TRAILERSIZE_REPLACEMENT = '/Size %d'
STARTXREF_TOKEN = '{{startxref}}'
STARTXREF_REPLACEMENT = 'startxref\n%d'
OBJECT_PATTERN = r'\{\{object\s+(\d+)\s+(\d+)\}\}'
OBJECT_REPLACEMENT = r'\1 \2 obj'
STREAMLEN_TOKEN = '{{streamlen}}'
STREAMLEN_REPLACEMENT = '/Length %d'
def __init__(self):
self.streamlen_state = StreamLenState.START
self.streamlens = []
self.offset = 0
self.xref_offset = 0
self.max_object_number = 0
self.objects = {}
def insert_xref_entry(self, object_number, generation_number):
self.objects[object_number] = (self.offset, generation_number)
self.max_object_number = max(self.max_object_number, object_number)
def generate_xref_table(self):
result = self.XREF_REPLACEMENT % (0, self.max_object_number + 1)
for i in range(0, self.max_object_number + 1):
if i in self.objects:
result += self.XREF_REPLACEMENT_N % self.objects[i]
else:
result += self.XREF_REPLACEMENT_F
return result
def preprocess_line(self, line):
if self.STREAMLEN_TOKEN in line:
assert self.streamlen_state == StreamLenState.START
self.streamlen_state = StreamLenState.FIND_STREAM
self.streamlens.append(0)
return
if (self.streamlen_state == StreamLenState.FIND_STREAM and
line.rstrip() == 'stream'):
self.streamlen_state = StreamLenState.FIND_ENDSTREAM
return
if self.streamlen_state == StreamLenState.FIND_ENDSTREAM:
if line.rstrip() == 'endstream':
self.streamlen_state = StreamLenState.START
else:
self.streamlens[-1] += len(line)
def process_line(self, line):
if self.HEADER_TOKEN in line:
line = line.replace(self.HEADER_TOKEN, self.HEADER_REPLACEMENT)
if self.STREAMLEN_TOKEN in line:
sub = self.STREAMLEN_REPLACEMENT % self.streamlens.pop(0)
line = re.sub(self.STREAMLEN_TOKEN, sub, line)
if self.XREF_TOKEN in line:
self.xref_offset = self.offset
line = self.generate_xref_table()
if self.TRAILER_TOKEN in line:
replacement = self.TRAILER_REPLACEMENT % (self.max_object_number + 1)
line = line.replace(self.TRAILER_TOKEN, replacement)
if self.TRAILERSIZE_TOKEN in line:
replacement = self.TRAILERSIZE_REPLACEMENT % (self.max_object_number + 1)
line = line.replace(self.TRAILERSIZE_TOKEN, replacement)
if self.STARTXREF_TOKEN in line:
replacement = self.STARTXREF_REPLACEMENT % self.xref_offset
line = line.replace(self.STARTXREF_TOKEN, replacement)
match = re.match(self.OBJECT_PATTERN, line)
if match:
self.insert_xref_entry(int(match.group(1)), int(match.group(2)))
line = re.sub(self.OBJECT_PATTERN, self.OBJECT_REPLACEMENT, line)
self.offset += len(line)
return line
def expand_file(infile, output_path):
processor = TemplateProcessor()
try:
with open(output_path, 'wb') as outfile:
preprocessed = cStringIO.StringIO()
for line in infile:
preprocessed.write(line)
processor.preprocess_line(line)
preprocessed.seek(0)
for line in preprocessed:
outfile.write(processor.process_line(line))
except IOError:
print >> sys.stderr, 'failed to process %s' % input_path
def insert_includes(input_path, output_file, visited_set):
input_path = os.path.normpath(input_path)
if input_path in visited_set:
print >> sys.stderr, 'Circular inclusion %s, ignoring' % input_path
return
visited_set.add(input_path)
try:
with open(input_path, 'rb') as infile:
for line in infile:
match = re.match(r'\s*\{\{include\s+(.+)\}\}', line)
if match:
insert_includes(
os.path.join(os.path.dirname(input_path), match.group(1)),
output_file, visited_set)
else:
# Replace CRLF with LF line endings for .in files.
_, file_extension = os.path.splitext(input_path)
if file_extension in EXTENSION_OVERRIDE_LINE_ENDINGS:
line = line.replace(WINDOWS_LINE_ENDING, UNIX_LINE_ENDING)
output_file.write(line)
except IOError:
print >> sys.stderr, 'failed to include %s' % input_path
raise
visited_set.discard(input_path)
def main():
parser = optparse.OptionParser()
parser.add_option('--output-dir', default='')
options, args = parser.parse_args()
for testcase_path in args:
testcase_filename = os.path.basename(testcase_path)
testcase_root, _ = os.path.splitext(testcase_filename)
output_dir = os.path.dirname(testcase_path)
if options.output_dir:
output_dir = options.output_dir
intermediate_stream = cStringIO.StringIO()
insert_includes(testcase_path, intermediate_stream, set())
intermediate_stream.seek(0)
output_path = os.path.join(output_dir, testcase_root + '.pdf')
expand_file(intermediate_stream, output_path)
return 0
if __name__ == '__main__':
sys.exit(main())