auto import from //depot/cupcake/@135843

1 files changed, 352 insertions, 0 deletions

diff --git a/scripts/divide_and_compress.py b/scripts/divide_and_compress.py
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+#!/usr/bin/python2.4
+#
+# Copyright (C) 2008 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+"""Module to compress directories in to series of zip files.
+
+This module will take a directory and compress all its contents, including
+child directories into a series of zip files named N.zip where 'N' ranges from
+0 to infinity. The zip files will all be below a certain specified maximum
+threshold.
+
+The directory is compressed with a depth first traversal, each directory's
+file contents being compressed as it is visisted, before the compression of any
+child directory's contents. In this way the files within an archive are ordered
+and the archives themselves are ordered.
+
+The class also constructs a 'main.py' file intended for use with Google App
+Engine with a custom App Engine program not currently distributed with this
+code base. The custom App Engine runtime can leverage the index files written
+out by this class to more quickly locate which zip file to serve a given URL
+from.
+"""
+
+__author__ = 'jmatt@google.com (Justin Mattson)'
+
+from optparse import OptionParser
+import os
+import stat
+import sys
+import zipfile
+from zipfile import ZipFile
+import divide_and_compress_constants
+
+
+def Main(argv):
+  parser = CreateOptionsParser()
+  (options, args) = parser.parse_args()
+  VerifyArguments(options, parser)
+  zipper = DirectoryZipper(options.destination, 
+                           options.sourcefiles, 
+                           ParseSize(options.filesize),
+                           options.compress)
+  zipper.StartCompress()
+  
+
+def CreateOptionsParser():
+  rtn = OptionParser()
+  rtn.add_option('-s', '--sourcefiles', dest='sourcefiles', default=None,
+                 help='The directory containing the files to compress')
+  rtn.add_option('-d', '--destination', dest='destination', default=None,
+                 help=('Where to put the archive files, this should not be'
+                       ' a child of where the source files exist.'))
+  rtn.add_option('-f', '--filesize', dest='filesize', default='1M',
+                 help=('Maximum size of archive files. A number followed by' 
+                       'a magnitude indicator, eg. 1000000B == one million '
+                       'BYTES, 500K == five hundred KILOBYTES, 1.2M == one '
+                       'point two MEGABYTES. 1M == 1048576 BYTES'))
+  rtn.add_option('-n', '--nocompress', action='store_false', dest='compress',
+                 default=True, 
+                 help=('Whether the archive files should be compressed, or '
+                       'just a concatenation of the source files'))
+  return rtn
+
+
+def VerifyArguments(options, parser):
+  try:
+    if options.sourcefiles is None or options.destination is None:
+      parser.print_help()
+      sys.exit(-1)
+  except (AttributeError), err:
+    parser.print_help()
+    sys.exit(-1)
+
+
+def ParseSize(size_str):
+  if len(size_str) < 2:
+    raise ValueError(('filesize argument not understood, please include'
+                      ' a numeric value and magnitude indicator'))
+  magnitude = size_str[len(size_str)-1:]
+  if not magnitude in ('K', 'B', 'M'):
+    raise ValueError(('filesize magnitude indicator not valid, must be \'K\','
+                      '\'B\', or \'M\''))
+  numeral = float(size_str[0:len(size_str)-1])
+  if magnitude == 'K':
+    numeral *= 1024
+  elif magnitude == 'M':
+    numeral *= 1048576
+  return int(numeral)
+
+
+class DirectoryZipper(object):
+  """Class to compress a directory and all its sub-directories."""  
+  current_archive = None
+  output_dir = None
+  base_path = None
+  max_size = None
+  compress = None
+  index_fp = None
+
+  def __init__(self, output_path, base_dir, archive_size, enable_compression):
+    """DirectoryZipper constructor.
+
+    Args:
+      output_path: the path to write the archives and index file to
+      base_dir: the directory to compress
+      archive_size: the maximum size, in bytes, of a single archive file
+      enable_compression: whether or not compression should be enabled, if
+        disabled, the files will be written into an uncompresed zip
+    """
+    self.output_dir = output_path
+    self.current_archive = '0.zip'
+    self.base_path = base_dir
+    self.max_size = archive_size
+    self.compress = enable_compression
+
+  def StartCompress(self):
+    """Start compress of the directory.
+
+    This will start the compression process and write the archives to the
+    specified output directory. It will also produce an 'index.txt' file in the
+    output directory that maps from file to archive.
+    """
+    self.index_fp = open(''.join([self.output_dir, 'main.py']), 'w')
+    self.index_fp.write(divide_and_compress_constants.file_preamble)
+    os.path.walk(self.base_path, self.CompressDirectory, 1)
+    self.index_fp.write(divide_and_compress_constants.file_endpiece)
+    self.index_fp.close()
+
+  def RemoveLastFile(self, archive_path=None):
+    """Removes the last item in the archive.
+
+    This removes the last item in the archive by reading the items out of the
+    archive, adding them to a new archive, deleting the old archive, and
+    moving the new archive to the location of the old archive.
+
+    Args:
+      archive_path: Path to the archive to modify. This archive should not be
+        open elsewhere, since it will need to be deleted.
+    Return:
+      A new ZipFile object that points to the modified archive file
+    """
+    if archive_path is None:
+      archive_path = ''.join([self.output_dir, self.current_archive])
+
+    # Move the old file and create a new one at its old location
+    ext_offset = archive_path.rfind('.')
+    old_archive = ''.join([archive_path[0:ext_offset], '-old',
+                           archive_path[ext_offset:]])
+    os.rename(archive_path, old_archive)
+    old_fp = self.OpenZipFileAtPath(old_archive, mode='r')
+
+    if self.compress:
+      new_fp = self.OpenZipFileAtPath(archive_path,
+                                      mode='w',
+                                      compress=zipfile.ZIP_DEFLATED)
+    else:
+      new_fp = self.OpenZipFileAtPath(archive_path,
+                                      mode='w',
+                                      compress=zipfile.ZIP_STORED)
+    
+    # Read the old archive in a new archive, except the last one
+    zip_members = enumerate(old_fp.infolist())
+    num_members = len(old_fp.infolist())
+    while num_members > 1:
+      this_member = zip_members.next()[1]
+      new_fp.writestr(this_member.filename, old_fp.read(this_member.filename))
+      num_members -= 1
+
+    # Close files and delete the old one
+    old_fp.close()
+    new_fp.close()
+    os.unlink(old_archive)
+
+  def OpenZipFileAtPath(self, path, mode=None, compress=zipfile.ZIP_DEFLATED):
+    """This method is mainly for testing purposes, eg dependency injection."""
+    if mode is None:
+      if os.path.exists(path):
+        mode = 'a'
+      else:
+        mode = 'w'
+
+    if mode == 'r':
+      return ZipFile(path, mode)
+    else:
+      return ZipFile(path, mode, compress)
+
+  def CompressDirectory(self, irrelevant, dir_path, dir_contents):
+    """Method to compress the given directory.
+
+    This method compresses the directory 'dir_path'. It will add to an existing
+    zip file that still has space and create new ones as necessary to keep zip
+    file sizes under the maximum specified size. This also writes out the
+    mapping of files to archives to the self.index_fp file descriptor
+
+    Args:
+      irrelevant: a numeric identifier passed by the os.path.walk method, this
+        is not used by this method
+      dir_path: the path to the directory to compress
+      dir_contents: a list of directory contents to be compressed
+    """
+    
+    # construct the queue of files to be added that this method will use
+    # it seems that dir_contents is given in reverse alphabetical order,
+    # so put them in alphabetical order by inserting to front of the list
+    dir_contents.sort()
+    zip_queue = []
+    if dir_path[len(dir_path) - 1:] == os.sep:
+      for filename in dir_contents:
+        zip_queue.append(''.join([dir_path, filename]))
+    else:
+      for filename in dir_contents:
+        zip_queue.append(''.join([dir_path, os.sep, filename]))
+    compress_bit = zipfile.ZIP_DEFLATED
+    if not self.compress:
+      compress_bit = zipfile.ZIP_STORED
+
+    # zip all files in this directory, adding to existing archives and creating
+    # as necessary
+    while len(zip_queue) > 0:
+      target_file = zip_queue[0]
+      if os.path.isfile(target_file):
+        self.AddFileToArchive(target_file, compress_bit)
+        
+        # see if adding the new file made our archive too large
+        if not self.ArchiveIsValid():
+          
+          # IF fixing fails, the last added file was to large, skip it
+          # ELSE the current archive filled normally, make a new one and try
+          #  adding the file again
+          if not self.FixArchive('SIZE'):
+            zip_queue.pop(0)
+          else:
+            self.current_archive = '%i.zip' % (
+                int(self.current_archive[
+                    0:self.current_archive.rfind('.zip')]) + 1)
+        else:
+
+          # if this the first file in the archive, write an index record
+          self.WriteIndexRecord()
+          zip_queue.pop(0)
+      else:
+        zip_queue.pop(0)
+
+  def WriteIndexRecord(self):
+    """Write an index record to the index file.
+
+    Only write an index record if this is the first file to go into archive
+
+    Returns:
+      True if an archive record is written, False if it isn't
+    """
+    archive = self.OpenZipFileAtPath(
+        ''.join([self.output_dir, self.current_archive]), 'r')
+    archive_index = archive.infolist()
+    if len(archive_index) == 1:
+      self.index_fp.write(
+          '[\'%s\', \'%s\'],\n' % (self.current_archive,
+                                   archive_index[0].filename))
+      archive.close()
+      return True
+    else:
+      archive.close()
+      return False
+
+  def FixArchive(self, problem):
+    """Make the archive compliant.
+
+    Args:
+      problem: the reason the archive is invalid
+
+    Returns:
+      Whether the file(s) removed to fix the archive could conceivably be
+      in an archive, but for some reason can't be added to this one.
+    """
+    archive_path = ''.join([self.output_dir, self.current_archive])
+    rtn_value = None
+    
+    if problem == 'SIZE':
+      archive_obj = self.OpenZipFileAtPath(archive_path, mode='r')
+      num_archive_files = len(archive_obj.infolist())
+      
+      # IF there is a single file, that means its too large to compress,
+      # delete the created archive
+      # ELSE do normal finalization
+      if num_archive_files == 1:
+        print ('WARNING: %s%s is too large to store.' % (
+            self.base_path, archive_obj.infolist()[0].filename))
+        archive_obj.close()
+        os.unlink(archive_path)
+        rtn_value = False
+      else:
+        self.RemoveLastFile(''.join([self.output_dir, self.current_archive]))
+        archive_obj.close()
+        print 'Final archive size for %s is %i' % (
+            self.current_archive, os.stat(archive_path)[stat.ST_SIZE])
+        rtn_value = True
+    return rtn_value
+
+  def AddFileToArchive(self, filepath, compress_bit):
+    """Add the file at filepath to the current archive.
+
+    Args:
+      filepath: the path of the file to add
+      compress_bit: whether or not this fiel should be compressed when added
+
+    Returns:
+      True if the file could be added (typically because this is a file) or
+      False if it couldn't be added (typically because its a directory)
+    """
+    curr_archive_path = ''.join([self.output_dir, self.current_archive])
+    if os.path.isfile(filepath):
+      if os.stat(filepath)[stat.ST_SIZE] > 1048576:
+        print 'Warning: %s is potentially too large to serve on GAE' % filepath
+      archive = self.OpenZipFileAtPath(curr_archive_path,
+                                       compress=compress_bit)
+      # add the file to the archive
+      archive.write(filepath, filepath[len(self.base_path):])
+      archive.close()
+      return True
+    else:
+      return False
+
+  def ArchiveIsValid(self):
+    """Check whether the archive is valid.
+
+    Currently this only checks whether the archive is under the required size.
+    The thought is that eventually this will do additional validation
+
+    Returns:
+      True if the archive is valid, False if its not
+    """
+    archive_path = ''.join([self.output_dir, self.current_archive])
+    if os.stat(archive_path)[stat.ST_SIZE] > self.max_size:
+      return False
+    else:
+      return True
+
+if __name__ == '__main__':
+  Main(sys.argv)