zeroinstall/zerostore/__init__.py

   1 # Copyright (C) 2006, Thomas Leonard
   2 # See the README file for details, or visit http://0install.net.
   3
   4 import os
   5 import shutil
   6 import traceback
   7 from tempfile import mkdtemp, mkstemp
   8 import sha
   9 import re
  10 from logging import debug, info, warn
  11
  12 import manifest
  13 from zeroinstall.injector import basedir
  14 from zeroinstall import SafeException
  15
  16 class BadDigest(SafeException): pass
  17 class NotStored(SafeException): pass
  18
  19 def copytree2(src, dst):
  20         names = os.listdir(src)
  21         assert os.path.isdir(dst)
  22         errors = []
  23         for name in names:
  24                 srcname = os.path.join(src, name)
  25                 dstname = os.path.join(dst, name)
  26                 if os.path.islink(srcname):
  27                         linkto = os.readlink(srcname)
  28                         os.symlink(linkto, dstname)
  29                 elif os.path.isdir(srcname):
  30                         os.mkdir(dstname)
  31                         mtime = os.lstat(srcname).st_mtime
  32                         copytree2(srcname, dstname)
  33                         os.utime(dstname, (mtime, mtime))
  34                 else:
  35                         shutil.copy2(srcname, dstname)
  36
  37 class Store:
  38         def __init__(self, dir):
  39                 self.dir = dir
  40
  41         def lookup(self, digest):
  42                 alg, value = digest.split('=', 1)
  43                 assert alg == 'sha1'
  44                 assert '/' not in value
  45                 int(value, 16)          # Check valid format
  46                 dir = os.path.join(self.dir, digest)
  47                 if os.path.isdir(dir):
  48                         return dir
  49                 return None
  50
  51         def add_archive_to_cache(self, required_digest, data, url, extract = None):
  52                 import unpack
  53                 assert required_digest.startswith('sha1=')
  54                 info("Caching new implementation (digest %s)", required_digest)
  55
  56                 if self.lookup(required_digest):
  57                         info("Not adding %s as it already exists!", required_digest)
  58                         return
  59
  60                 if not os.path.isdir(self.dir):
  61                         os.makedirs(self.dir)
  62                 tmp = mkdtemp(dir = self.dir, prefix = 'tmp-')
  63                 try:
  64                         unpack.unpack_archive(url, data, tmp, extract)
  65                 except:
  66                         shutil.rmtree(tmp)
  67                         raise
  68
  69                 try:
  70                         self.check_manifest_and_rename(required_digest, tmp, extract)
  71                 except Exception, ex:
  72                         warn("Leaving extracted directory as %s", tmp)
  73                         raise
  74
  75         def add_dir_to_cache(self, required_digest, path):
  76                 if self.lookup(required_digest):
  77                         info("Not adding %s as it already exists!", required_digest)
  78                         return
  79
  80                 if not os.path.isdir(self.dir):
  81                         os.makedirs(self.dir)
  82                 tmp = mkdtemp(dir = self.dir, prefix = 'tmp-')
  83                 copytree2(path, tmp)
  84                 try:
  85                         self.check_manifest_and_rename(required_digest, tmp)
  86                 except:
  87                         warn("Error importing directory.")
  88                         warn("Deleting %s", tmp)
  89                         shutil.rmtree(tmp)
  90                         raise
  91
  92         def check_manifest_and_rename(self, required_digest, tmp, extract = None):
  93                 if extract:
  94                         extracted = os.path.join(tmp, extract)
  95                         if not os.path.isdir(extracted):
  96                                 raise Exception('Directory %s not found in archive' % extract)
  97                 else:
  98                         extracted = tmp
  99
 100                 sha1 = 'sha1=' + manifest.add_manifest_file(extracted, sha.new()).hexdigest()
 101                 if sha1 != required_digest:
 102                         raise BadDigest('Incorrect manifest -- archive is corrupted.\n'
 103                                         'Required digest: %s\n'
 104                                         'Actual digest: %s\n' %
 105                                         (required_digest, sha1))
 106
 107                 final_name = os.path.join(self.dir, required_digest)
 108                 if os.path.isdir(final_name):
 109                         raise Exception("Item %s already stored." % final_name)
 110                 if extract:
 111                         os.rename(os.path.join(tmp, extract), final_name)
 112                         os.rmdir(tmp)
 113                 else:
 114                         os.rename(tmp, final_name)
 115
 116 class Stores(object):
 117         __slots__ = ['stores']
 118
 119         def __init__(self):
 120                 user_store = os.path.join(basedir.xdg_cache_home, '0install.net', 'implementations')
 121                 self.stores = [Store(user_store)]
 122
 123                 impl_dirs = basedir.load_first_config('0install.net', 'injector',
 124                                                           'implementation-dirs')
 125                 debug("Location of 'implementation-dirs' config file being used: '%s'", impl_dirs)
 126                 if impl_dirs:
 127                         dirs = file(impl_dirs)
 128                 else:
 129                         dirs = ['/var/cache/0install.net/implementations']
 130                 for directory in dirs:
 131                         directory = directory.strip()
 132                         if directory and not directory.startswith('#'):
 133                                 if os.path.isdir(directory):
 134                                         self.stores.append(Store(directory))
 135                                         debug("Added system store '%s'", directory)
 136                                 else:
 137                                         info("Ignoring non-directory store '%s'", directory)
 138
 139         def lookup(self, digest):
 140                 """Search for digest in all stores."""
 141                 assert digest
 142                 if '/' in digest or '=' not in digest:
 143                         raise BadDigest('Syntax error in digest (use ALG=VALUE)')
 144                 for store in self.stores:
 145                         path = store.lookup(digest)
 146                         if path:
 147                                 return path
 148                 raise NotStored("Item with digest '%s' not found in stores. Searched:\n- %s" %
 149                         (digest, '\n- '.join([s.dir for s in self.stores])))
 150
 151         def add_dir_to_cache(self, required_digest, dir):
 152                 self.stores[0].add_dir_to_cache(required_digest, dir)
 153
 154         def add_archive_to_cache(self, required_digest, data, url, extract = None):
 155                 self.stores[0].add_archive_to_cache(required_digest, data, url, extract)