patch.py - chromium/tools/depot_tools.git - Git at Google

 # coding=utf8
 # Copyright (c) 2011 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.
 """Utility functions to handle patches."""

 import posixpath
 import os
 import re


 class UnsupportedPatchFormat(Exception):
   def __init__(self, filename, status):
     super(UnsupportedPatchFormat, self).__init__(filename, status)
     self.filename = filename
     self.status = status

   def __str__(self):
     out = 'Can\'t process patch for file %s.' % self.filename
     if self.status:
       out += '\n%s' % self.status
     return out


 class FilePatchBase(object):
   """Defines a single file being modified.

   '/' is always used instead of os.sep for consistency.
   """
   is_delete = False
   is_binary = False

   def __init__(self, filename):
     self.filename = None
     self._set_filename(filename)

   def _set_filename(self, filename):
     self.filename = filename.replace('\\', '/')
     # Blacklist a few characters for simplicity.
     for i in ('%', '$', '..', '\'', '"'):
       if i in self.filename:
         self._fail('Can\'t use \'%s\' in filename.' % i)
     for i in ('/', 'CON', 'COM'):
       if self.filename.startswith(i):
         self._fail('Filename can\'t start with \'%s\'.' % i)

   def get(self):
     raise NotImplementedError('Nothing to grab')

   def set_relpath(self, relpath):
     if not relpath:
       return
     relpath = relpath.replace('\\', '/')
     if relpath[0] == '/':
       self._fail('Relative path starts with %s' % relpath[0])
     self._set_filename(posixpath.join(relpath, self.filename))

   def _fail(self, msg):
     raise UnsupportedPatchFormat(self.filename, msg)


 class FilePatchDelete(FilePatchBase):
   """Deletes a file."""
   is_delete = True

   def __init__(self, filename, is_binary):
     super(FilePatchDelete, self).__init__(filename)
     self.is_binary = is_binary

   def get(self):
     raise NotImplementedError('Nothing to grab')


 class FilePatchBinary(FilePatchBase):
   """Content of a new binary file."""
   is_binary = True

   def __init__(self, filename, data, svn_properties):
     super(FilePatchBinary, self).__init__(filename)
     self.data = data
     self.svn_properties = svn_properties or []

   def get(self):
     return self.data


 class FilePatchDiff(FilePatchBase):
   """Patch for a single file."""

   def __init__(self, filename, diff, svn_properties):
     super(FilePatchDiff, self).__init__(filename)
     if not diff:
       self._fail('File doesn\'t have a diff.')
     self.diff_header, self.diff_hunks = self._split_header(diff)
     self.svn_properties = svn_properties or []
     self.is_git_diff = self._is_git_diff_header(self.diff_header)
     self.patchlevel = 0
     if self.is_git_diff:
       self._verify_git_header()
       assert not svn_properties
     else:
       self._verify_svn_header()

   def get(self):
     return self.diff_header + self.diff_hunks

   def set_relpath(self, relpath):
     old_filename = self.filename
     super(FilePatchDiff, self).set_relpath(relpath)
     # Update the header too.
     self.diff_header = self.diff_header.replace(old_filename, self.filename)

   def _split_header(self, diff):
     """Splits a diff in two: the header and the hunks."""
     header = []
     hunks = diff.splitlines(True)
     while hunks:
       header.append(hunks.pop(0))
       if header[-1].startswith('--- '):
         break
     else:
       # Some diff may not have a ---/+++ set like a git rename with no change or
       # a svn diff with only property change.
       pass

     if hunks:
       if not hunks[0].startswith('+++ '):
         self._fail('Inconsistent header')
       header.append(hunks.pop(0))
       if hunks:
         if not hunks[0].startswith('@@ '):
           self._fail('Inconsistent hunk header')

     # Mangle any \\ in the header to /.
     header_lines = ('Index:', 'diff', 'copy', 'rename', '+++', '---')
     basename = os.path.basename(self.filename)
     for i in xrange(len(header)):
       if (header[i].split(' ', 1)[0] in header_lines or
           header[i].endswith(basename)):
         header[i] = header[i].replace('\\', '/')
     return ''.join(header), ''.join(hunks)

   @staticmethod
   def _is_git_diff_header(diff_header):
     """Returns True if the diff for a single files was generated with git."""
     # Delete: http://codereview.chromium.org/download/issue6368055_22_29.diff
     # Rename partial change:
     # http://codereview.chromium.org/download/issue6250123_3013_6010.diff
     # Rename no change:
     # http://codereview.chromium.org/download/issue6287022_3001_4010.diff
     return any(l.startswith('diff --git') for l in diff_header.splitlines())

   def mangle(self, string):
     """Mangle a file path."""
     return '/'.join(string.replace('\\', '/').split('/')[self.patchlevel:])

   def _verify_git_header(self):
     """Sanity checks the header.

     Expects the following format:

     <garbagge>
     diff --git (|a/)<filename> (|b/)<filename>
     <similarity>
     <filemode changes>
     <index>
     <copy|rename from>
     <copy|rename to>
     --- <filename>
     +++ <filename>

     Everything is optional except the diff --git line.
     """
     lines = self.diff_header.splitlines()

     # Verify the diff --git line.
     old = None
     new = None
     while lines:
       match = re.match(r'^diff \-\-git (.*?) (.*)$', lines.pop(0))
       if not match:
         continue
       old = match.group(1).replace('\\', '/')
       new = match.group(2).replace('\\', '/')
       if old.startswith('a/') and new.startswith('b/'):
         self.patchlevel = 1
         old = old[2:]
         new = new[2:]
       # The rename is about the new file so the old file can be anything.
       if new not in (self.filename, 'dev/null'):
         self._fail('Unexpected git diff output name %s.' % new)
       if old == 'dev/null' and new == 'dev/null':
         self._fail('Unexpected /dev/null git diff.')
       break

     if not old or not new:
       self._fail('Unexpected git diff; couldn\'t find git header.')

     # Handle these:
     # rename from <>
     # rename to <>
     # copy from <>
     # copy to <>
     while lines:
       if lines[0].startswith('--- '):
         break
       match = re.match(r'^(rename|copy) from (.+)$', lines.pop(0))
       if not match:
         continue
       if old != match.group(2):
         self._fail('Unexpected git diff input name for %s.' % match.group(1))
       if not lines:
         self._fail('Missing git diff output name for %s.' % match.group(1))
       match = re.match(r'^(rename|copy) to (.+)$', lines.pop(0))
       if not match:
         self._fail('Missing git diff output name for %s.' % match.group(1))
       if new != match.group(2):
         self._fail('Unexpected git diff output name for %s.' % match.group(1))

     # Handle ---/+++
     while lines:
       match = re.match(r'^--- (.*)$', lines.pop(0))
       if not match:
         continue
       if old != self.mangle(match.group(1)) and match.group(1) != '/dev/null':
         self._fail('Unexpected git diff: %s != %s.' % (old, match.group(1)))
       if not lines:
         self._fail('Missing git diff output name.')
       match = re.match(r'^\+\+\+ (.*)$', lines.pop(0))
       if not match:
         self._fail('Unexpected git diff: --- not following +++.')
       if new != self.mangle(match.group(1)) and '/dev/null' != match.group(1):
         self._fail('Unexpected git diff: %s != %s.' % (new, match.group(1)))
       assert not lines, '_split_header() is broken'
       break

   def _verify_svn_header(self):
     """Sanity checks the header.

     A svn diff can contain only property changes, in that case there will be no
     proper header. To make things worse, this property change header is
     localized.
     """
     lines = self.diff_header.splitlines()
     while lines:
       match = re.match(r'^--- ([^\t]+).*$', lines.pop(0))
       if not match:
         continue
       # For copy and renames, it's possible that the -- line doesn't match +++,
       # so don't check match.group(1) to match self.filename or '/dev/null', it
       # can be anything else.
       # TODO(maruel): Handle rename/copy explicitly.
       # if match.group(1) not in (self.filename, '/dev/null'):
       #  self.source_file = match.group(1)
       if not lines:
         self._fail('Nothing after header.')
       match = re.match(r'^\+\+\+ ([^\t]+).*$', lines.pop(0))
       if not match:
         self._fail('Unexpected diff: --- not following +++.')
       if match.group(1) not in (self.filename, '/dev/null'):
         self._fail('Unexpected diff: %s.' % match.group(1))
       assert not lines, '_split_header() is broken'
       break
     else:
       # Cheap check to make sure the file name is at least mentioned in the
       # 'diff' header. That the only remaining invariant.
       if not self.filename in self.diff_header:
         self._fail('Diff seems corrupted.')


 class PatchSet(object):
   """A list of FilePatch* objects."""

   def __init__(self, patches):
     self.patches = patches
     for p in self.patches:
       assert isinstance(p, FilePatchBase)

   def set_relpath(self, relpath):
     """Used to offset the patch into a subdirectory."""
     for patch in self.patches:
       patch.set_relpath(relpath)

   def __iter__(self):
     for patch in self.patches:
       yield patch

   @property
   def filenames(self):
     return [p.filename for p in self.patches]
	# coding=utf8
	# Copyright (c) 2011 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.
	"""Utility functions to handle patches."""

	import posixpath
	import os
	import re


	class UnsupportedPatchFormat(Exception):
	def __init__(self, filename, status):
	super(UnsupportedPatchFormat, self).__init__(filename, status)
	self.filename = filename
	self.status = status

	def __str__(self):
	out = 'Can\'t process patch for file %s.' % self.filename
	if self.status:
	out += '\n%s' % self.status
	return out


	class FilePatchBase(object):
	"""Defines a single file being modified.

	'/' is always used instead of os.sep for consistency.
	"""
	is_delete = False
	is_binary = False

	def __init__(self, filename):
	self.filename = None
	self._set_filename(filename)

	def _set_filename(self, filename):
	self.filename = filename.replace('\\', '/')
	# Blacklist a few characters for simplicity.
	for i in ('%', '$', '..', '\'', '"'):
	if i in self.filename:
	self._fail('Can\'t use \'%s\' in filename.' % i)
	for i in ('/', 'CON', 'COM'):
	if self.filename.startswith(i):
	self._fail('Filename can\'t start with \'%s\'.' % i)

	def get(self):
	raise NotImplementedError('Nothing to grab')

	def set_relpath(self, relpath):
	if not relpath:
	return
	relpath = relpath.replace('\\', '/')
	if relpath[0] == '/':
	self._fail('Relative path starts with %s' % relpath[0])
	self._set_filename(posixpath.join(relpath, self.filename))

	def _fail(self, msg):
	raise UnsupportedPatchFormat(self.filename, msg)


	class FilePatchDelete(FilePatchBase):
	"""Deletes a file."""
	is_delete = True

	def __init__(self, filename, is_binary):
	super(FilePatchDelete, self).__init__(filename)
	self.is_binary = is_binary

	def get(self):
	raise NotImplementedError('Nothing to grab')


	class FilePatchBinary(FilePatchBase):
	"""Content of a new binary file."""
	is_binary = True

	def __init__(self, filename, data, svn_properties):
	super(FilePatchBinary, self).__init__(filename)
	self.data = data
	self.svn_properties = svn_properties or []

	def get(self):
	return self.data


	class FilePatchDiff(FilePatchBase):
	"""Patch for a single file."""

	def __init__(self, filename, diff, svn_properties):
	super(FilePatchDiff, self).__init__(filename)
	if not diff:
	self._fail('File doesn\'t have a diff.')
	self.diff_header, self.diff_hunks = self._split_header(diff)
	self.svn_properties = svn_properties or []
	self.is_git_diff = self._is_git_diff_header(self.diff_header)
	self.patchlevel = 0
	if self.is_git_diff:
	self._verify_git_header()
	assert not svn_properties
	else:
	self._verify_svn_header()

	def get(self):
	return self.diff_header + self.diff_hunks

	def set_relpath(self, relpath):
	old_filename = self.filename
	super(FilePatchDiff, self).set_relpath(relpath)
	# Update the header too.
	self.diff_header = self.diff_header.replace(old_filename, self.filename)

	def _split_header(self, diff):
	"""Splits a diff in two: the header and the hunks."""
	header = []
	hunks = diff.splitlines(True)
	while hunks:
	header.append(hunks.pop(0))
	if header[-1].startswith('--- '):
	break
	else:
	# Some diff may not have a ---/+++ set like a git rename with no change or
	# a svn diff with only property change.
	pass

	if hunks:
	if not hunks[0].startswith('+++ '):
	self._fail('Inconsistent header')
	header.append(hunks.pop(0))
	if hunks:
	if not hunks[0].startswith('@@ '):
	self._fail('Inconsistent hunk header')

	# Mangle any \\ in the header to /.
	header_lines = ('Index:', 'diff', 'copy', 'rename', '+++', '---')
	basename = os.path.basename(self.filename)
	for i in xrange(len(header)):
	if (header[i].split(' ', 1)[0] in header_lines or
	header[i].endswith(basename)):
	header[i] = header[i].replace('\\', '/')
	return ''.join(header), ''.join(hunks)

	@staticmethod
	def _is_git_diff_header(diff_header):
	"""Returns True if the diff for a single files was generated with git."""
	# Delete: http://codereview.chromium.org/download/issue6368055_22_29.diff
	# Rename partial change:
	# http://codereview.chromium.org/download/issue6250123_3013_6010.diff
	# Rename no change:
	# http://codereview.chromium.org/download/issue6287022_3001_4010.diff
	return any(l.startswith('diff --git') for l in diff_header.splitlines())

	def mangle(self, string):
	"""Mangle a file path."""
	return '/'.join(string.replace('\\', '/').split('/')[self.patchlevel:])

	def _verify_git_header(self):
	"""Sanity checks the header.

	Expects the following format:

	<garbagge>
	diff --git (\|a/)<filename> (\|b/)<filename>
	<similarity>
	<filemode changes>
	<index>
	<copy\|rename from>
	<copy\|rename to>
	--- <filename>
	+++ <filename>

	Everything is optional except the diff --git line.
	"""
	lines = self.diff_header.splitlines()

	# Verify the diff --git line.
	old = None
	new = None
	while lines:
	match = re.match(r'^diff \-\-git (.?) (.)$', lines.pop(0))
	if not match:
	continue
	old = match.group(1).replace('\\', '/')
	new = match.group(2).replace('\\', '/')
	if old.startswith('a/') and new.startswith('b/'):
	self.patchlevel = 1
	old = old[2:]
	new = new[2:]
	# The rename is about the new file so the old file can be anything.
	if new not in (self.filename, 'dev/null'):
	self._fail('Unexpected git diff output name %s.' % new)
	if old == 'dev/null' and new == 'dev/null':
	self._fail('Unexpected /dev/null git diff.')
	break

	if not old or not new:
	self._fail('Unexpected git diff; couldn\'t find git header.')

	# Handle these:
	# rename from <>
	# rename to <>
	# copy from <>
	# copy to <>
	while lines:
	if lines[0].startswith('--- '):
	break
	match = re.match(r'^(rename\|copy) from (.+)$', lines.pop(0))
	if not match:
	continue
	if old != match.group(2):
	self._fail('Unexpected git diff input name for %s.' % match.group(1))
	if not lines:
	self._fail('Missing git diff output name for %s.' % match.group(1))
	match = re.match(r'^(rename\|copy) to (.+)$', lines.pop(0))
	if not match:
	self._fail('Missing git diff output name for %s.' % match.group(1))
	if new != match.group(2):
	self._fail('Unexpected git diff output name for %s.' % match.group(1))

	# Handle ---/+++
	while lines:
	match = re.match(r'^--- (.*)$', lines.pop(0))
	if not match:
	continue
	if old != self.mangle(match.group(1)) and match.group(1) != '/dev/null':
	self._fail('Unexpected git diff: %s != %s.' % (old, match.group(1)))
	if not lines:
	self._fail('Missing git diff output name.')
	match = re.match(r'^\+\+\+ (.*)$', lines.pop(0))
	if not match:
	self._fail('Unexpected git diff: --- not following +++.')
	if new != self.mangle(match.group(1)) and '/dev/null' != match.group(1):
	self._fail('Unexpected git diff: %s != %s.' % (new, match.group(1)))
	assert not lines, '_split_header() is broken'
	break

	def _verify_svn_header(self):
	"""Sanity checks the header.

	A svn diff can contain only property changes, in that case there will be no
	proper header. To make things worse, this property change header is
	localized.
	"""
	lines = self.diff_header.splitlines()
	while lines:
	match = re.match(r'^--- ([^\t]+).*$', lines.pop(0))
	if not match:
	continue
	# For copy and renames, it's possible that the -- line doesn't match +++,
	# so don't check match.group(1) to match self.filename or '/dev/null', it
	# can be anything else.
	# TODO(maruel): Handle rename/copy explicitly.
	# if match.group(1) not in (self.filename, '/dev/null'):
	# self.source_file = match.group(1)
	if not lines:
	self._fail('Nothing after header.')
	match = re.match(r'^\+\+\+ ([^\t]+).*$', lines.pop(0))
	if not match:
	self._fail('Unexpected diff: --- not following +++.')
	if match.group(1) not in (self.filename, '/dev/null'):
	self._fail('Unexpected diff: %s.' % match.group(1))
	assert not lines, '_split_header() is broken'
	break
	else:
	# Cheap check to make sure the file name is at least mentioned in the
	# 'diff' header. That the only remaining invariant.
	if not self.filename in self.diff_header:
	self._fail('Diff seems corrupted.')


	class PatchSet(object):
	"""A list of FilePatch* objects."""

	def __init__(self, patches):
	self.patches = patches
	for p in self.patches:
	assert isinstance(p, FilePatchBase)

	def set_relpath(self, relpath):
	"""Used to offset the patch into a subdirectory."""
	for patch in self.patches:
	patch.set_relpath(relpath)

	def __iter__(self):
	for patch in self.patches:
	yield patch

	@property
	def filenames(self):
	return [p.filename for p in self.patches]