[Python-checkins] python/nondist/sandbox/pep262 install_db.py,NONE,1.1

2003年3月30日 09:05:16 -0800

Update of /cvsroot/python/python/nondist/sandbox/pep262
In directory sc8-pr-cvs1:/tmp/cvs-serv7316
Added Files:
	install_db.py 
Log Message:
Old installation database code that I have lying around. I haven't checked 
that it still works, but will begin working on it after lunch.
--- NEW FILE: install_db.py ---
"""distutils.install_db
Code for the database of installed Python packages.
"""
# XXX next steps:
# 1) write test cases for this module
# 2) integrate into install_* commands
# 2.5) take it to the Distutils-SIG
# 3) write a package manager
__revision__ = "$Id: install_db.py,v 1.1 2003年03月30日 17:05:13 akuchling Exp $"
import os, sys
import binascii, cStringIO, sha, rfc822
from distutils.dist import DistributionMetadata
INSTALLDB = ('%s%slib%spython%i.%i%sinstall' % (sys.prefix, os.sep, 
 os.sep,
 sys.version_info[0],
 sys.version_info[1],
 os.sep))
INSTALLDB = '/tmp/i'
_inst_db = None
def get_install_db ():
 global _inst_db
 if _inst_db is None:
 _inst_db = InstallationDatabase()
 return _inst_db
class InstallationDatabase:
 def __init__ (self, path=None):
 """InstallationDatabase(path:string)
 Read the installation database rooted at the specified path.
 If path is None, INSTALLDB is used as the default. 
 """
 if path is None:
 path = INSTALLDB
 self.path = path
 self._cache = {}

 def get_package (self, package_name):
 """get_package(package_name:string) : Package
 Get the object corresponding to a single package.
 """
 try:
 return self._cache[package_name]
 except KeyError:
 for package in self:
 if package.name == package_name:
 self._cache[package_name] = package
 return package
 return None

 def list_packages (self):
 """list_packages() : [Package]
 Return a list of all packages installed on the system, 
 enumerated in no particular order.
 """
 return list(self)

 def find_package (self, path):
 """find_file(path:string) : Package
 Search and return the package containing the file 'path'. 
 Returns None if the file doesn't belong to any package
 that the InstallationDatabase knows about.
 XXX should this work for directories?
 """
 for package in self:
 if package.has_file(path):
 return package
 return None

 def __iter__ (self):
 return _InstallDBIterator(self)

# class InstallationDatabase
class _InstallDBIterator:
 def __init__ (self, instdb):
 self.instdb = instdb
 self.queue = [instdb.path]

 def next (self):
 if len(self.queue) == 0:
 raise StopIteration
 while len(self.queue):
 filename = self.queue.pop(0)
 if os.path.isdir(filename):
 for fn2 in os.listdir(filename):
 self.queue.append( os.path.join(filename, fn2))
 else:
 break
 return Package(filename)

class Package(DistributionMetadata):
 """Instance attributes:
 filename : string
 Name of file in which the package's data is stored.
 files : {string : (size:int, perms:int, owner:string, group:string,
 digest:string)}
 Dictionary mapping the path of a file installed by this package 
 to information about the file.
 """
 def __init__ (self, filename=None):
 DistributionMetadata.__init__(self)
 self.files = {}
 self.filename = filename
 if filename is not None:
 self.read_file()

 def __repr__ (self):
 return '<Package %s: %s>' % (self.name, self.filename)
 def read_file (self):
 input = open(self.filename, 'rt')
 sections = input.readline().split()
 if 'PKG-INFO' in sections:
 m = rfc822.Message(input)
 self.read_pkg_info(m)

 if 'FILES' in sections:
 while 1:
 line = input.readline()
 if line.strip() == "":
 break
 line = line.split()
 line = line[:6]
 path, size, perms, owner, group, shasum = line
 self.files[path] = (int(size), int(perms),
 owner, group, shasum)
 input.close()

 def add_file (self, path):
 """add_file(path:string):None
 Record the size, ownership, &c., information for an installed file.
 XXX as written, this would stat() the file. Should the size/perms/
 checksum all be provided as parameters to this method instead?
 """
 if not os.path.isfile(path):
 return
 # XXX what to do when hashing: binary or text mode?
 input = open(path, 'rb')
 digest = _hash_file(input)
 input.close()
 stats = os.stat(path)
 self.files[path] = (stats.st_size, stats.st_mode,
 stats.st_uid, stats.st_gid, digest)

 def has_file (self, path):
 """has_file(path:string) : Boolean
 Returns true if the specified path belongs to a file in this
 package.
 """
 return self.files.has_key(path)
 def check_file (self, path):
 """check_file(path:string) : [string]
 Checks whether the file's size, checksum, and ownership match,
 returning a possibly-empty list of mismatches.
 """
 input = open(path, 'rb')
 digest = _hash_file(input)
 input.close()
 expected = self.files[path]
 stats = os.stat(path)
 L = []
 if stats.st_size != expected[0]:
 L.append('Modified size: %i (expected %i)' %
 (stats.st_size, expected[0]))
 if stats.st_mode != expected[1]:
 L.append('Modified mode: %i (expected %i)' %
 (stats.st_mode, expected[1]))
 if expected[2] != 'unknown' and stats.st_uid != expected[2]:
 L.append('Modified user ownership: %s (expected %s)' %
 (stats.st_uid, expected[2]))
 if expected[3] != 'unknown' and stats.st_gid != expected[3]:
 L.append('Modified group ownership: %s (expected %s)' %
 (stats.st_gid, expected[3]))
 if digest != expected[4]:
 L.append('Incorrect SHA digest')
 return L

 def as_text (self):
 output = cStringIO.StringIO()
 print >>output, 'PKG-INFO FILES'
 self._write_pkg_info(output)
 output.write('\n')
 for path, t in self.files.items():
 line = '%s\t%s\t%s\t%s\t%s\t%s' % (path,
 t[0], t[1], t[2], t[3], t[4])
 print >>output, line
 output.write('\n')
 return output.getvalue()

# class Package
def _hash_file (input):
 h = sha.new()
 while 1:
 data = input.read(4096)
 if data == "":
 break
 h.update(data)
 digest = binascii.b2a_hex(h.digest())
 return digest
if __name__ == '__main__':
 db = InstallationDatabase('/tmp/i/')
 for p in db:
 print p.__dict__
 print db.list_packages()
 f = open('/tmp/i2', 'wt')
 f.write(p.as_text())
 f.close()
 print p.check_file('/www/bin/apachectl')