pym/portage_db_flat.py

# Copyright 2004 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id: /var/cvsroot/gentoo-src/portage/pym/Attic/portage_db_flat.py,v 1.13.2.6 2005/04/19 07:14:17 ferringb Exp $


import types
import os
import stat

import portage_db_template

# since this format is massively deprecated, 
# we're hardcoding the previously weird line count
magic_line_count = 22

class database(portage_db_template.database):
	def module_init(self):
		self.lastkey  = None # Cache
		self.lastval  = None # Cache

		self.fullpath = self.path + "/" + self.category + "/"

		if not os.path.exists(self.fullpath):
			prevmask=os.umask(0)
			os.makedirs(self.fullpath, 02775)
			os.umask(prevmask)
			try:
				os.chown(self.fullpath, self.uid, self.gid)
				os.chmod(self.fullpath, 02775)
			except SystemExit, e:
				raise
			except:
				pass
		
	def has_key(self,key):
		if os.path.exists(self.fullpath+key):
			return 1
		return 0
	
	def keys(self):
		# XXX: NEED TOOLS SEPERATED
		# return portage.listdir(self.fullpath,filesonly=1)
		mykeys = []
		for x in os.listdir(self.fullpath):
			if os.path.isfile(self.fullpath+x) and not x.startswith(".update."):
				mykeys += [x]
		return mykeys

	def get_values(self,key, data=None):
		""" do not use data unless you know what it does."""

		if not key:
			raise KeyError, "key is not set to a valid value"

		mydict = {}
		if data == None:
			try:
				# give buffering a hint of the pretty much maximal cache size we deal with
				myf = open(self.fullpath+key, "r", 8192)
			except OSError:
				# either the file didn't exist, or it was removed under our feet.
				raise KeyError("failed reading key")

			# nuke the newlines right off the batt.
			data = myf.read().splitlines()
			mydict["_mtime_"] = os.fstat(myf.fileno()).st_mtime
			myf.close()
		else:
			mydict["_mtime_"] = data.pop(-1)

		# rely on exceptions to note differing line counts.
		try:
			for x in range(magic_line_count):
				mydict[self.dbkeys[x]] = data[x]

		except IndexError:
			raise ValueError, "Key count mistmatch"

		return mydict
	
	def set_values(self,key, val, raw=False):
		if not key:
			raise KeyError, "No key provided. key:%s val:%s" % (key,val)
		if not val:
			raise ValueError, "No value provided. key:%s val:%s" % (key,val)
			
		# XXX threaded cache updates won't play nice with this.
		# need a synchronization primitive, or locking (of the fileno, not a seperate file)
		# to correctly handle threading.

		update_fp = self.fullpath + ".update." + str(os.getpid()) + "." + key
		myf = open(update_fp,"w")
		if not raw:
			myf.writelines( [ str(val[x]) +"\n" for x in self.dbkeys] )
			if len(self.dbkeys) != magic_line_count:
				myf.writelines(["\n"] * len(self.dbkeys) - magic_line_count)
			mtime = val["_mtime_"]
		else:
			mtime = val.pop(-1)
			myf.writelines(val)
		myf.close()
		
		os.chown(update_fp, self.uid, self.gid)
		os.chmod(update_fp, 0664)
		os.utime(update_fp, (-1,long(mtime)))
		os.rename(update_fp, self.fullpath+key)

	def del_key(self,key):
		try:
			os.unlink(self.fullpath+key)
		except OSError, oe:
			# just attempt it without checking, due to the fact that
			# a cache update could be in progress.
			self.lastkey = None
			self.lastval = None
			return 0
		return 1
			
	def sync(self):
		return
	
	def close(self):
		return