virtualenv/res/lib/patch.py
author cavaliet
Thu, 04 Aug 2011 12:54:02 +0200
changeset 125 5c3ed9c919bb
parent 50 0d59e0522d36
permissions -rw-r--r--
New search feature on top right corner. Advanced search included in published projects tab. Colored icons. Change css to avoid scroll on contents and projects table.

""" Patch utility to apply unified diffs

    Brute-force line-by-line non-recursive parsing 

    Copyright (c) 2008-2010 anatoly techtonik
    Available under the terms of MIT license

    Project home: http://code.google.com/p/python-patch/


    $Id: patch.py 76 2010-04-08 19:10:21Z techtonik $
    $HeadURL: https://python-patch.googlecode.com/svn/trunk/patch.py $
"""

__author__ = "techtonik.rainforce.org"
__version__ = "10.04"

import copy
import logging
import re
# cStringIO doesn't support unicode in 2.5
from StringIO import StringIO
from logging import debug, info, warning

from os.path import exists, isfile, abspath
from os import unlink


#------------------------------------------------
# Logging is controlled by "python_patch" logger

debugmode = False

logger = logging.getLogger("python_patch")
loghandler = logging.StreamHandler()
logger.addHandler(loghandler)

debug = logger.debug
info = logger.info
warning = logger.warning

#: disable library logging by default
logger.setLevel(logging.CRITICAL)

#------------------------------------------------


def fromfile(filename):
  """ Parse patch file and return Patch() object
  """

  info("reading patch from file %s" % filename)
  fp = open(filename, "rb")
  patch = Patch(fp)
  fp.close()
  return patch


def fromstring(s):
  """ Parse text string and return Patch() object
  """

  return Patch(
           StringIO.StringIO(s)    
         )



class HunkInfo(object):
  """ Parsed hunk data container (hunk starts with @@ -R +R @@) """

  def __init__(self):
    self.startsrc=None #: line count starts with 1
    self.linessrc=None
    self.starttgt=None
    self.linestgt=None
    self.invalid=False
    self.text=[]

  def copy(self):
    return copy.copy(self)

#  def apply(self, estream):
#    """ write hunk data into enumerable stream
#        return strings one by one until hunk is
#        over
#
#        enumerable stream are tuples (lineno, line)
#        where lineno starts with 0
#    """
#    pass



class Patch(object):

  def __init__(self, stream=None):

    # define Patch data members
    # table with a row for every source file

    #: list of source filenames
    self.source=None
    self.target=None
    #: list of lists of hunks
    self.hunks=None
    #: file endings statistics for every hunk
    self.hunkends=None

    if stream:
      self.parse(stream)

  def copy(self):
    return copy.copy(self)

  def parse(self, stream):
    """ parse unified diff """
    self.source = []
    self.target = []
    self.hunks = []
    self.hunkends = []

    # define possible file regions that will direct the parser flow
    header = False    # comments before the patch body
    filenames = False # lines starting with --- and +++

    hunkhead = False  # @@ -R +R @@ sequence
    hunkbody = False  #
    hunkskip = False  # skipping invalid hunk mode

    header = True
    lineends = dict(lf=0, crlf=0, cr=0)
    nextfileno = 0
    nexthunkno = 0    #: even if index starts with 0 user messages number hunks from 1

    # hunkinfo holds parsed values, hunkactual - calculated
    hunkinfo = HunkInfo()
    hunkactual = dict(linessrc=None, linestgt=None)

    fe = enumerate(stream)
    for lineno, line in fe:

      # analyze state
      if header and line.startswith("--- "):
        header = False
        # switch to filenames state
        filenames = True
      #: skip hunkskip and hunkbody code until you read definition of hunkhead
      if hunkbody:
        # process line first
        if re.match(r"^[- \+\\]", line):
            # gather stats about line endings
            if line.endswith("\r\n"):
              self.hunkends[nextfileno-1]["crlf"] += 1
            elif line.endswith("\n"):
              self.hunkends[nextfileno-1]["lf"] += 1
            elif line.endswith("\r"):
              self.hunkends[nextfileno-1]["cr"] += 1
              
            if line.startswith("-"):
              hunkactual["linessrc"] += 1
            elif line.startswith("+"):
              hunkactual["linestgt"] += 1
            elif not line.startswith("\\"):
              hunkactual["linessrc"] += 1
              hunkactual["linestgt"] += 1
            hunkinfo.text.append(line)
            # todo: handle \ No newline cases
        else:
            warning("invalid hunk no.%d at %d for target file %s" % (nexthunkno, lineno+1, self.target[nextfileno-1]))
            # add hunk status node
            self.hunks[nextfileno-1].append(hunkinfo.copy())
            self.hunks[nextfileno-1][nexthunkno-1]["invalid"] = True
            # switch to hunkskip state
            hunkbody = False
            hunkskip = True

        # check exit conditions
        if hunkactual["linessrc"] > hunkinfo.linessrc or hunkactual["linestgt"] > hunkinfo.linestgt:
            warning("extra hunk no.%d lines at %d for target %s" % (nexthunkno, lineno+1, self.target[nextfileno-1]))
            # add hunk status node
            self.hunks[nextfileno-1].append(hunkinfo.copy())
            self.hunks[nextfileno-1][nexthunkno-1]["invalid"] = True
            # switch to hunkskip state
            hunkbody = False
            hunkskip = True
        elif hunkinfo.linessrc == hunkactual["linessrc"] and hunkinfo.linestgt == hunkactual["linestgt"]:
            self.hunks[nextfileno-1].append(hunkinfo.copy())
            # switch to hunkskip state
            hunkbody = False
            hunkskip = True

            # detect mixed window/unix line ends
            ends = self.hunkends[nextfileno-1]
            if ((ends["cr"]!=0) + (ends["crlf"]!=0) + (ends["lf"]!=0)) > 1:
              warning("inconsistent line ends in patch hunks for %s" % self.source[nextfileno-1])
            if debugmode:
              debuglines = dict(ends)
              debuglines.update(file=self.target[nextfileno-1], hunk=nexthunkno)
              debug("crlf: %(crlf)d  lf: %(lf)d  cr: %(cr)d\t - file: %(file)s hunk: %(hunk)d" % debuglines)

      if hunkskip:
        match = re.match("^@@ -(\d+)(,(\d+))? \+(\d+)(,(\d+))?", line)
        if match:
          # switch to hunkhead state
          hunkskip = False
          hunkhead = True
        elif line.startswith("--- "):
          # switch to filenames state
          hunkskip = False
          filenames = True
          if debugmode and len(self.source) > 0:
            debug("- %2d hunks for %s" % (len(self.hunks[nextfileno-1]), self.source[nextfileno-1]))

      if filenames:
        if line.startswith("--- "):
          if nextfileno in self.source:
            warning("skipping invalid patch for %s" % self.source[nextfileno])
            del self.source[nextfileno]
            # double source filename line is encountered
            # attempt to restart from this second line
          re_filename = "^--- ([^\t]+)"
          match = re.match(re_filename, line)
          # todo: support spaces in filenames
          if match:
            self.source.append(match.group(1).strip())
          else:
            warning("skipping invalid filename at line %d" % lineno)
            # switch back to header state
            filenames = False
            header = True
        elif not line.startswith("+++ "):
          if nextfileno in self.source:
            warning("skipping invalid patch with no target for %s" % self.source[nextfileno])
            del self.source[nextfileno]
          else:
            # this should be unreachable
            warning("skipping invalid target patch")
          filenames = False
          header = True
        else:
          if nextfileno in self.target:
            warning("skipping invalid patch - double target at line %d" % lineno)
            del self.source[nextfileno]
            del self.target[nextfileno]
            nextfileno -= 1
            # double target filename line is encountered
            # switch back to header state
            filenames = False
            header = True
          else:
            re_filename = "^\+\+\+ ([^\t]+)"
            match = re.match(re_filename, line)
            if not match:
              warning("skipping invalid patch - no target filename at line %d" % lineno)
              # switch back to header state
              filenames = False
              header = True
            else:
              self.target.append(match.group(1).strip())
              nextfileno += 1
              # switch to hunkhead state
              filenames = False
              hunkhead = True
              nexthunkno = 0
              self.hunks.append([])
              self.hunkends.append(lineends.copy())
              continue

      if hunkhead:
        match = re.match("^@@ -(\d+)(,(\d+))? \+(\d+)(,(\d+))?", line)
        if not match:
          if nextfileno-1 not in self.hunks:
            warning("skipping invalid patch with no hunks for file %s" % self.target[nextfileno-1])
            # switch to header state
            hunkhead = False
            header = True
            continue
          else:
            # switch to header state
            hunkhead = False
            header = True
        else:
          hunkinfo.startsrc = int(match.group(1))
          hunkinfo.linessrc = 1
          if match.group(3): hunkinfo.linessrc = int(match.group(3))
          hunkinfo.starttgt = int(match.group(4))
          hunkinfo.linestgt = 1
          if match.group(6): hunkinfo.linestgt = int(match.group(6))
          hunkinfo.invalid = False
          hunkinfo.text = []

          hunkactual["linessrc"] = hunkactual["linestgt"] = 0

          # switch to hunkbody state
          hunkhead = False
          hunkbody = True
          nexthunkno += 1
          continue
    else:
      if not hunkskip:
        warning("patch file incomplete - %s" % filename)
        # sys.exit(?)
      else:
        # duplicated message when an eof is reached
        if debugmode and len(self.source) > 0:
            debug("- %2d hunks for %s" % (len(self.hunks[nextfileno-1]), self.source[nextfileno-1]))

    info("total files: %d  total hunks: %d" % (len(self.source), sum(len(hset) for hset in self.hunks)))


  def apply(self):
    """ apply parsed patch """

    total = len(self.source)
    for fileno, filename in enumerate(self.source):

      f2patch = filename
      if not exists(f2patch):
        f2patch = self.target[fileno]
        if not exists(f2patch):
          warning("source/target file does not exist\n--- %s\n+++ %s" % (filename, f2patch))
          continue
      if not isfile(f2patch):
        warning("not a file - %s" % f2patch)
        continue
      filename = f2patch

      info("processing %d/%d:\t %s" % (fileno+1, total, filename))

      # validate before patching
      f2fp = open(filename)
      hunkno = 0
      hunk = self.hunks[fileno][hunkno]
      hunkfind = []
      hunkreplace = []
      validhunks = 0
      canpatch = False
      for lineno, line in enumerate(f2fp):
        if lineno+1 < hunk.startsrc:
          continue
        elif lineno+1 == hunk.startsrc:
          hunkfind = [x[1:].rstrip("\r\n") for x in hunk.text if x[0] in " -"]
          hunkreplace = [x[1:].rstrip("\r\n") for x in hunk.text if x[0] in " +"]
          #pprint(hunkreplace)
          hunklineno = 0

          # todo \ No newline at end of file

        # check hunks in source file
        if lineno+1 < hunk.startsrc+len(hunkfind)-1:
          if line.rstrip("\r\n") == hunkfind[hunklineno]:
            hunklineno+=1
          else:
            debug("hunk no.%d doesn't match source file %s" % (hunkno+1, filename))
            # file may be already patched, but we will check other hunks anyway
            hunkno += 1
            if hunkno < len(self.hunks[fileno]):
              hunk = self.hunks[fileno][hunkno]
              continue
            else:
              break

        # check if processed line is the last line
        if lineno+1 == hunk.startsrc+len(hunkfind)-1:
          debug("file %s hunk no.%d -- is ready to be patched" % (filename, hunkno+1))
          hunkno+=1
          validhunks+=1
          if hunkno < len(self.hunks[fileno]):
            hunk = self.hunks[fileno][hunkno]
          else:
            if validhunks == len(self.hunks[fileno]):
              # patch file
              canpatch = True
              break
      else:
        if hunkno < len(self.hunks[fileno]):
          warning("premature end of source file %s at hunk %d" % (filename, hunkno+1))

      f2fp.close()

      if validhunks < len(self.hunks[fileno]):
        if self._match_file_hunks(filename, self.hunks[fileno]):
          warning("already patched  %s" % filename)
        else:
          warning("source file is different - %s" % filename)
      if canpatch:
        backupname = filename+".orig"
        if exists(backupname):
          warning("can't backup original file to %s - aborting" % backupname)
        else:
          import shutil
          shutil.move(filename, backupname)
          if self.write_hunks(backupname, filename, self.hunks[fileno]):
            warning("successfully patched %s" % filename)
            unlink(backupname)
          else:
            warning("error patching file %s" % filename)
            shutil.copy(filename, filename+".invalid")
            warning("invalid version is saved to %s" % filename+".invalid")
            # todo: proper rejects
            shutil.move(backupname, filename)

    # todo: check for premature eof


  def can_patch(self, filename):
    """ Check if specified filename can be patched. Returns None if file can
    not be found among source filenames. False if patch can not be applied
    clearly. True otherwise.

    :returns: True, False or None
    """
    idx = self._get_file_idx(filename, source=True)
    if idx == None:
      return None
    return self._match_file_hunks(filename, self.hunks[idx])
    

  def _match_file_hunks(self, filepath, hunks):
    matched = True
    fp = open(abspath(filepath))

    class NoMatch(Exception):
      pass

    lineno = 1
    line = fp.readline()
    hno = None
    try:
      for hno, h in enumerate(hunks):
        # skip to first line of the hunk
        while lineno < h.starttgt:
          if not len(line): # eof
            debug("check failed - premature eof before hunk: %d" % (hno+1))
            raise NoMatch
          line = fp.readline()
          lineno += 1
        for hline in h.text:
          if hline.startswith("-"):
            continue
          if not len(line):
            debug("check failed - premature eof on hunk: %d" % (hno+1))
            # todo: \ No newline at the end of file
            raise NoMatch
          if line.rstrip("\r\n") != hline[1:].rstrip("\r\n"):
            debug("file is not patched - failed hunk: %d" % (hno+1))
            raise NoMatch
          line = fp.readline()
          lineno += 1

    except NoMatch:
      matched = False
      # todo: display failed hunk, i.e. expected/found

    fp.close()
    return matched


  def patch_stream(self, instream, hunks):
    """ Generator that yields stream patched with hunks iterable
    
        Converts lineends in hunk lines to the best suitable format
        autodetected from input
    """

    # todo: At the moment substituted lineends may not be the same
    #       at the start and at the end of patching. Also issue a
    #       warning/throw about mixed lineends (is it really needed?)

    hunks = iter(hunks)

    srclineno = 1

    lineends = {'\n':0, '\r\n':0, '\r':0}
    def get_line():
      """
      local utility function - return line from source stream
      collecting line end statistics on the way
      """
      line = instream.readline()
        # 'U' mode works only with text files
      if line.endswith("\r\n"):
        lineends["\r\n"] += 1
      elif line.endswith("\n"):
        lineends["\n"] += 1
      elif line.endswith("\r"):
        lineends["\r"] += 1
      return line

    for hno, h in enumerate(hunks):
      debug("hunk %d" % (hno+1))
      # skip to line just before hunk starts
      while srclineno < h.startsrc:
        yield get_line()
        srclineno += 1

      for hline in h.text:
        # todo: check \ No newline at the end of file
        if hline.startswith("-") or hline.startswith("\\"):
          get_line()
          srclineno += 1
          continue
        else:
          if not hline.startswith("+"):
            get_line()
            srclineno += 1
          line2write = hline[1:]
          # detect if line ends are consistent in source file
          if sum([bool(lineends[x]) for x in lineends]) == 1:
            newline = [x for x in lineends if lineends[x] != 0][0]
            yield line2write.rstrip("\r\n")+newline
          else: # newlines are mixed
            yield line2write
     
    for line in instream:
      yield line


  def write_hunks(self, srcname, tgtname, hunks):
    src = open(srcname, "rb")
    tgt = open(tgtname, "wb")

    debug("processing target file %s" % tgtname)

    tgt.writelines(self.patch_stream(src, hunks))

    tgt.close()
    src.close()
    return True
  

  def _get_file_idx(self, filename, source=None):
    """ Detect index of given filename within patch.

        :param filename:
        :param source: search filename among sources (True),
                       targets (False), or both (None)
        :returns: int or None
    """
    filename = abspath(filename)
    if source == True or source == None:
      for i,fnm in enumerate(self.source):
        if filename == abspath(fnm):
          return i  
    if source == False or source == None:
      for i,fnm in enumerate(self.target):
        if filename == abspath(fnm):
          return i  




from optparse import OptionParser
from os.path import exists
import sys

if __name__ == "__main__":
  opt = OptionParser(usage="%prog [options] unipatch-file", version="python-patch %s" % __version__)
  opt.add_option("--debug", action="store_true", dest="debugmode", help="debug mode")
  (options, args) = opt.parse_args()

  if not args:
    opt.print_version()
    opt.print_help()
    sys.exit()
  debugmode = options.debugmode
  patchfile = args[0]
  if not exists(patchfile) or not isfile(patchfile):
    sys.exit("patch file does not exist - %s" % patchfile)


  if debugmode:
    loglevel = logging.DEBUG
    logformat = "%(levelname)8s %(message)s"
  else:
    loglevel = logging.INFO
    logformat = "%(message)s"
  logger.setLevel(loglevel)
  loghandler.setFormatter(logging.Formatter(logformat))



  patch = fromfile(patchfile)
  #pprint(patch)
  patch.apply()

  # todo: document and test line ends handling logic - patch.py detects proper line-endings
  #       for inserted hunks and issues a warning if patched file has incosistent line ends