replacement cache subsystem that's gestated in 2.1 and 3.0.

it rocks your world, baby.

svn path=/main/branches/2.0/; revision=2257

1 files changed, 129 insertions, 0 deletions

diff --git a/pym/cache/flat_hash.py b/pym/cache/flat_hash.py
new file mode 100644
index 000000000..6882afd7e
--- /dev/null
+++ b/pym/cache/flat_hash.py
@@ -0,0 +1,129 @@
+# Copyright: 2005 Gentoo Foundation
+# Author(s): Brian Harring (ferringb@gentoo.org)
+# License: GPL2
+# $Id: flat_list.py 1911 2005-08-25 03:44:21Z ferringb $
+
+import fs_template
+import cache_errors
+import os, stat
+from mappings import LazyLoad, ProtectedDict
+from template import reconstruct_eclasses
+# store the current key order *here*.
+class database(fs_template.FsBased):
+
+	autocommits = True
+
+	def __init__(self, *args, **config):
+		super(database,self).__init__(*args, **config)
+		self.location = os.path.join(self.location, 
+			self.label.lstrip(os.path.sep).rstrip(os.path.sep))
+
+		if not os.path.exists(self.location):
+			self._ensure_dirs()
+
+	def __getitem__(self, cpv):
+		fp = os.path.join(self.location, cpv)
+		try:
+			def curry(*args):
+				def callit(*args2):
+					return args[0](*args[1:]+args2)
+				return callit
+			return ProtectedDict(LazyLoad(curry(self._pull, fp, cpv), initial_items=[("_mtime_", os.stat(fp).st_mtime)]))
+		except OSError:
+			raise KeyError(cpv)
+		return self._getitem(cpv)
+
+	def _pull(self, fp, cpv):
+		try:
+			myf = open(fp,"r")
+		except IOError:
+			raise KeyError(cpv)
+		except OSError, e:
+			raise cache_errors.CacheCorruption(cpv, e)
+		try:
+			d = self._parse_data(myf, cpv)
+		except (OSError, ValueError), e:
+			myf.close()
+			raise cache_errors.CacheCorruption(cpv, e)
+		myf.close()
+		return d
+
+
+	def _parse_data(self, data, cpv, mtime=0):
+		d = dict(map(lambda x:x.rstrip().split("=", 1), data))
+		if mtime != 0:
+			d["_mtime_"] = long(mtime)
+		if "_eclasses_" in d:
+			d["_eclasses_"] = reconstruct_eclasses(cpv, d["_eclasses_"])
+		return d
+		
+		for x in self._known_keys:
+			if x not in d:
+				d[x] = ''
+
+
+		return d
+
+
+	def _setitem(self, cpv, values):
+#		import pdb;pdb.set_trace()
+		s = cpv.rfind("/")
+		fp = os.path.join(self.location,cpv[:s],".update.%i.%s" % (os.getpid(), cpv[s+1:]))
+		try:	myf=open(fp, "w")
+		except IOError, ie:
+			if ie.errno == 2:
+				try:
+					self._ensure_dirs(cpv)
+					myf=open(fp,"w")
+				except (OSError, IOError),e:
+					raise cache_errors.CacheCorruption(cpv, e)
+		except OSError, e:
+			raise cache_errors.CacheCorruption(cpv, e)
+		
+		for k, v in values.items():
+			if k != "_mtime_":
+				myf.writelines("%s=%s\n" % (k, v))
+
+		myf.close()
+		self._ensure_access(fp, mtime=values["_mtime_"])
+
+		#update written.  now we move it.
+
+		new_fp = os.path.join(self.location,cpv)
+		try:	os.rename(fp, new_fp)
+		except (OSError, IOError), e:
+			os.remove(fp)
+			raise cache_errors.CacheCorruption(cpv, e)
+
+
+	def _delitem(self, cpv):
+#		import pdb;pdb.set_trace()
+		try:
+			os.remove(os.path.join(self.location,cpv))
+		except OSError, e:
+			if e.errno == 2:
+				raise KeyError(cpv)
+			else:
+				raise cache_errors.CacheCorruption(cpv, e)
+
+
+	def has_key(self, cpv):
+		return os.path.exists(os.path.join(self.location, cpv))
+
+
+	def iterkeys(self):
+		"""generator for walking the dir struct"""
+		dirs = [self.location]
+		len_base = len(self.location)
+		while len(dirs):
+			for l in os.listdir(dirs[0]):
+				if l.endswith(".cpickle"):
+					continue
+				p = os.path.join(dirs[0],l)
+				st = os.lstat(p)
+				if stat.S_ISDIR(st.st_mode):
+					dirs.append(p)
+					continue
+				yield p[len_base+1:]
+			dirs.pop(0)
+