Python module to get (some) files from the repository.

With git it's not possible to simply export a set of paths from the server
directly. This module offers a similar functionality, but requires a local
clone of the repository. It calls git directly for maximum portability.

This is a prerequisite to making the deployment script used for Rockbox Utility
work again.

Change-Id: I1aca8ddd40d16b6268c1d6a2fc23ac59e964c3c6
This commit is contained in:
Dominik Riebeling 2012-02-05 19:17:53 +01:00
parent db3afb03a2
commit 909b96fa70

183
utils/common/gitscraper.py Executable file
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@ -0,0 +1,183 @@
#!/usr/bin/python
# __________ __ ___.
# Open \______ \ ____ ____ | | _\_ |__ _______ ___
# Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
# Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
# Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
# \/ \/ \/ \/ \/
#
# Copyright (c) 2012 Dominik Riebeling
#
# All files in this archive are subject to the GNU General Public License.
# See the file COPYING in the source tree root for full license agreement.
#
# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
# KIND, either express or implied.
#
'''Scrape files from a git repository.
This module provides functions to get a subset of files from a git repository.
The files to retrieve can be specified, and the git tree to work on can be
specified. That was arbitrary trees can be retrieved (like a subset of files
for a given tag).
Retrieved files can be packaged into a bzip2 compressed tarball or stored in a
given folder for processing afterwards.
Calls git commands directly for maximum compatibility.
'''
import re
import subprocess
import os
import tarfile
import tempfile
import shutil
def get_refs(repo):
'''Get dict matching refs to hashes from repository pointed to by repo.
@param repo Path to repository root.
@return Dict matching hashes to each ref.
'''
print "Getting list of refs"
output = subprocess.Popen(["git", "show-ref"], stdout=subprocess.PIPE,
stderr=subprocess.PIPE, cwd=repo)
cmdout = output.communicate()
refs = {}
if len(cmdout[1]) > 0:
print "An error occured!\n"
print cmdout[1]
return refs
for line in cmdout:
regex = re.findall(r'([a-f0-9]+)\s+(\S+)', line)
for r in regex:
# ref is the key, hash its value.
refs[r[1]] = r[0]
return refs
def get_lstree(repo, start, filterlist=[]):
'''Get recursive list of tree objects for a given tree.
@param repo Path to repository root.
@param start Hash identifying the tree.
@param filterlist List of paths to retrieve objecs hashes for.
An empty list will retrieve all paths.
@return Dict mapping filename to blob hash
'''
output = subprocess.Popen(["git", "ls-tree", "-r", start],
stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
cmdout = output.communicate()
objects = {}
if len(cmdout[1]) > 0:
print "An error occured!\n"
print cmdout[1]
return objects
for line in cmdout[0].split('\n'):
regex = re.findall(r'([0-9]+)\s+([a-z]+)\s+([0-9a-f]+)\s+(\S+)', line)
for rf in regex:
# filter
add = False
for f in filterlist:
if rf[3].find(f) == 0:
add = True
# If two files have the same content they have the same hash, so
# the filename has to be used as key.
if len(filterlist) == 0 or add == True:
if rf[3] in objects:
print "FATAL: key already exists in dict!"
return {}
objects[rf[3]] = rf[2]
return objects
def get_object(repo, blob, destfile):
'''Get an identified object from the repository.
@param repo Path to repository root.
@param blob hash for blob to retrieve.
@param destfile filename for blob output.
@return True if file was successfully written, False on error.
'''
output = subprocess.Popen(["git", "cat-file", "-p", blob],
stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
cmdout = output.communicate()
# make sure output path exists
if len(cmdout[1]) > 0:
print "An error occured!\n"
print cmdout[1]
return False
if not os.path.exists(os.path.dirname(destfile)):
os.makedirs(os.path.dirname(destfile))
f = open(destfile, 'w')
for line in cmdout[0]:
f.write(line)
f.close()
return True
def describe_treehash(repo, treehash):
'''Retrieve output of git-describe for a given hash.
@param repo Path to repository root.
@param treehash Hash identifying the tree / commit to describe.
@return Description string.
'''
output = subprocess.Popen(["git", "describe", treehash],
stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
cmdout = output.communicate()
if len(cmdout[1]) > 0:
print "An error occured!\n"
print cmdout[1]
return ""
return cmdout[0].rstrip()
def scrape_files(repo, treehash, filelist, dest=""):
'''Scrape list of files from repository.
@param repo Path to repository root.
@param treehash Hash identifying the tree.
@param filelist List of files to get from repository.
@param dest Destination path for files. Files will get retrieved with full
path from the repository, and the folder structure will get
created below dest as necessary.
@return Destination path.
'''
print "Scraping files from repository"
if dest == "":
dest = tempfile.mkdtemp()
treeobjects = get_lstree(repo, treehash, filelist)
for obj in treeobjects:
get_object(repo, treeobjects[obj], os.path.join(dest, obj))
return dest
def archive_files(repo, treehash, filelist, basename, tmpfolder=""):
'''Archive list of files into tarball.
@param repo Path to repository root.
@param treehash Hash identifying the tree.
@param filelist List of files to archive. All files in the archive if left
empty.
@param basename Basename (including path) of output file. Will get used as
basename inside of the archive as well (i.e. no tarbomb).
@param tmpfolder Folder to put intermediate files in. If no folder is given
a temporary one will get used.
@return Output filename.
'''
print "Archiving files from repository"
workfolder = scrape_files(repo, treehash, filelist, tmpfolder)
outfile = basename + ".tar.bz2"
tf = tarfile.open(outfile, "w:bz2")
tf.add(workfolder, basename)
tf.close()
if tmpfolder != workfolder:
shutil.rmtree(workfolder)
return outfile