diff --git a/bitbake/lib/bb/cache.py b/bitbake/lib/bb/cache.py
new file mode 100644
index 0000000..ef4d660
--- /dev/null
+++ b/bitbake/lib/bb/cache.py
@@ -0,0 +1,837 @@
+# ex:ts=4:sw=4:sts=4:et
+# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
+#
+# BitBake Cache implementation
+#
+# Caching of bitbake variables before task execution
+
+# Copyright (C) 2006        Richard Purdie
+# Copyright (C) 2012        Intel Corporation
+
+# but small sections based on code from bin/bitbake:
+# Copyright (C) 2003, 2004  Chris Larson
+# Copyright (C) 2003, 2004  Phil Blundell
+# Copyright (C) 2003 - 2005 Michael 'Mickey' Lauer
+# Copyright (C) 2005        Holger Hans Peter Freyther
+# Copyright (C) 2005        ROAD GmbH
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import os
+import logging
+from collections import defaultdict
+import bb.utils
+
+logger = logging.getLogger("BitBake.Cache")
+
+try:
+    import cPickle as pickle
+except ImportError:
+    import pickle
+    logger.info("Importing cPickle failed. "
+                "Falling back to a very slow implementation.")
+
+__cache_version__ = "148"
+
+def getCacheFile(path, filename, data_hash):
+    return os.path.join(path, filename + "." + data_hash)
+
+# RecipeInfoCommon defines common data retrieving methods
+# from meta data for caches. CoreRecipeInfo as well as other
+# Extra RecipeInfo needs to inherit this class
+class RecipeInfoCommon(object):
+
+    @classmethod
+    def listvar(cls, var, metadata):
+        return cls.getvar(var, metadata).split()
+
+    @classmethod
+    def intvar(cls, var, metadata):
+        return int(cls.getvar(var, metadata) or 0)
+
+    @classmethod
+    def depvar(cls, var, metadata):
+        return bb.utils.explode_deps(cls.getvar(var, metadata))
+
+    @classmethod
+    def pkgvar(cls, var, packages, metadata):
+        return dict((pkg, cls.depvar("%s_%s" % (var, pkg), metadata))
+                    for pkg in packages)
+
+    @classmethod
+    def taskvar(cls, var, tasks, metadata):
+        return dict((task, cls.getvar("%s_task-%s" % (var, task), metadata))
+                    for task in tasks)
+
+    @classmethod
+    def flaglist(cls, flag, varlist, metadata, squash=False):
+        out_dict = dict((var, metadata.getVarFlag(var, flag, True))
+                    for var in varlist)
+        if squash:
+            return dict((k,v) for (k,v) in out_dict.iteritems() if v)
+        else:
+            return out_dict
+
+    @classmethod
+    def getvar(cls, var, metadata):
+        return metadata.getVar(var, True) or ''
+
+
+class CoreRecipeInfo(RecipeInfoCommon):
+    __slots__ = ()
+
+    cachefile = "bb_cache.dat"   
+
+    def __init__(self, filename, metadata):      
+        self.file_depends = metadata.getVar('__depends', False)
+        self.timestamp = bb.parse.cached_mtime(filename)
+        self.variants = self.listvar('__VARIANTS', metadata) + ['']
+        self.appends = self.listvar('__BBAPPEND', metadata)
+        self.nocache = self.getvar('__BB_DONT_CACHE', metadata)
+
+        self.skipreason = self.getvar('__SKIPPED', metadata)
+        if self.skipreason:
+            self.pn = self.getvar('PN', metadata) or bb.parse.BBHandler.vars_from_file(filename,metadata)[0]
+            self.skipped = True
+            self.provides  = self.depvar('PROVIDES', metadata)
+            self.rprovides = self.depvar('RPROVIDES', metadata)
+            return
+
+        self.tasks = metadata.getVar('__BBTASKS', False)
+
+        self.pn = self.getvar('PN', metadata)
+        self.packages = self.listvar('PACKAGES', metadata)
+        if not self.pn in self.packages:
+            self.packages.append(self.pn)
+
+        self.basetaskhashes = self.taskvar('BB_BASEHASH', self.tasks, metadata)
+        self.hashfilename = self.getvar('BB_HASHFILENAME', metadata)
+
+        self.task_deps = metadata.getVar('_task_deps', False) or {'tasks': [], 'parents': {}}
+
+        self.skipped = False
+        self.pe = self.getvar('PE', metadata)
+        self.pv = self.getvar('PV', metadata)
+        self.pr = self.getvar('PR', metadata)
+        self.defaultpref = self.intvar('DEFAULT_PREFERENCE', metadata)
+        self.not_world = self.getvar('EXCLUDE_FROM_WORLD', metadata)
+        self.stamp = self.getvar('STAMP', metadata)
+        self.stampclean = self.getvar('STAMPCLEAN', metadata)        
+        self.stamp_base = self.flaglist('stamp-base', self.tasks, metadata)
+        self.stamp_base_clean = self.flaglist('stamp-base-clean', self.tasks, metadata)
+        self.stamp_extrainfo = self.flaglist('stamp-extra-info', self.tasks, metadata)
+        self.file_checksums = self.flaglist('file-checksums', self.tasks, metadata, True)
+        self.packages_dynamic = self.listvar('PACKAGES_DYNAMIC', metadata)
+        self.depends          = self.depvar('DEPENDS', metadata)
+        self.provides         = self.depvar('PROVIDES', metadata)
+        self.rdepends         = self.depvar('RDEPENDS', metadata)
+        self.rprovides        = self.depvar('RPROVIDES', metadata)
+        self.rrecommends      = self.depvar('RRECOMMENDS', metadata)
+        self.rprovides_pkg    = self.pkgvar('RPROVIDES', self.packages, metadata)
+        self.rdepends_pkg     = self.pkgvar('RDEPENDS', self.packages, metadata)
+        self.rrecommends_pkg  = self.pkgvar('RRECOMMENDS', self.packages, metadata)
+        self.inherits         = self.getvar('__inherit_cache', metadata)
+        self.fakerootenv      = self.getvar('FAKEROOTENV', metadata)
+        self.fakerootdirs     = self.getvar('FAKEROOTDIRS', metadata)
+        self.fakerootnoenv    = self.getvar('FAKEROOTNOENV', metadata)
+
+    @classmethod
+    def init_cacheData(cls, cachedata):
+        # CacheData in Core RecipeInfo Class
+        cachedata.task_deps = {}
+        cachedata.pkg_fn = {}
+        cachedata.pkg_pn = defaultdict(list)
+        cachedata.pkg_pepvpr = {}
+        cachedata.pkg_dp = {}
+
+        cachedata.stamp = {}
+        cachedata.stampclean = {}
+        cachedata.stamp_base = {}
+        cachedata.stamp_base_clean = {}
+        cachedata.stamp_extrainfo = {}
+        cachedata.file_checksums = {}
+        cachedata.fn_provides = {}
+        cachedata.pn_provides = defaultdict(list)
+        cachedata.all_depends = []
+
+        cachedata.deps = defaultdict(list)
+        cachedata.packages = defaultdict(list)
+        cachedata.providers = defaultdict(list)
+        cachedata.rproviders = defaultdict(list)
+        cachedata.packages_dynamic = defaultdict(list)
+
+        cachedata.rundeps = defaultdict(lambda: defaultdict(list))
+        cachedata.runrecs = defaultdict(lambda: defaultdict(list))
+        cachedata.possible_world = []
+        cachedata.universe_target = []
+        cachedata.hashfn = {}
+
+        cachedata.basetaskhash = {}
+        cachedata.inherits = {}
+        cachedata.fakerootenv = {}
+        cachedata.fakerootnoenv = {}
+        cachedata.fakerootdirs = {}
+
+    def add_cacheData(self, cachedata, fn):
+        cachedata.task_deps[fn] = self.task_deps
+        cachedata.pkg_fn[fn] = self.pn
+        cachedata.pkg_pn[self.pn].append(fn)
+        cachedata.pkg_pepvpr[fn] = (self.pe, self.pv, self.pr)
+        cachedata.pkg_dp[fn] = self.defaultpref
+        cachedata.stamp[fn] = self.stamp
+        cachedata.stampclean[fn] = self.stampclean
+        cachedata.stamp_base[fn] = self.stamp_base
+        cachedata.stamp_base_clean[fn] = self.stamp_base_clean
+        cachedata.stamp_extrainfo[fn] = self.stamp_extrainfo
+        cachedata.file_checksums[fn] = self.file_checksums
+
+        provides = [self.pn]
+        for provide in self.provides:
+            if provide not in provides:
+                provides.append(provide)
+        cachedata.fn_provides[fn] = provides
+
+        for provide in provides:
+            cachedata.providers[provide].append(fn)
+            if provide not in cachedata.pn_provides[self.pn]:
+                cachedata.pn_provides[self.pn].append(provide)
+
+        for dep in self.depends:
+            if dep not in cachedata.deps[fn]:
+                cachedata.deps[fn].append(dep)
+            if dep not in cachedata.all_depends:
+                cachedata.all_depends.append(dep)
+
+        rprovides = self.rprovides
+        for package in self.packages:
+            cachedata.packages[package].append(fn)
+            rprovides += self.rprovides_pkg[package]
+
+        for rprovide in rprovides:
+            cachedata.rproviders[rprovide].append(fn)
+
+        for package in self.packages_dynamic:
+            cachedata.packages_dynamic[package].append(fn)
+
+        # Build hash of runtime depends and recommends
+        for package in self.packages + [self.pn]:
+            cachedata.rundeps[fn][package] = list(self.rdepends) + self.rdepends_pkg[package]
+            cachedata.runrecs[fn][package] = list(self.rrecommends) + self.rrecommends_pkg[package]
+
+        # Collect files we may need for possible world-dep
+        # calculations
+        if self.not_world:
+            logger.debug(1, "EXCLUDE FROM WORLD: %s", fn)
+        else:
+            cachedata.possible_world.append(fn)
+
+        # create a collection of all targets for sanity checking
+        # tasks, such as upstream versions, license, and tools for
+        # task and image creation.
+        cachedata.universe_target.append(self.pn)
+
+        cachedata.hashfn[fn] = self.hashfilename
+        for task, taskhash in self.basetaskhashes.iteritems():
+            identifier = '%s.%s' % (fn, task)
+            cachedata.basetaskhash[identifier] = taskhash
+
+        cachedata.inherits[fn] = self.inherits
+        cachedata.fakerootenv[fn] = self.fakerootenv
+        cachedata.fakerootnoenv[fn] = self.fakerootnoenv
+        cachedata.fakerootdirs[fn] = self.fakerootdirs
+
+
+
+class Cache(object):
+    """
+    BitBake Cache implementation
+    """
+
+    def __init__(self, data, data_hash, caches_array):
+        # Pass caches_array information into Cache Constructor
+        # It will be used later for deciding whether we 
+        # need extra cache file dump/load support 
+        self.caches_array = caches_array
+        self.cachedir = data.getVar("CACHE", True)
+        self.clean = set()
+        self.checked = set()
+        self.depends_cache = {}
+        self.data = None
+        self.data_fn = None
+        self.cacheclean = True
+        self.data_hash = data_hash
+
+        if self.cachedir in [None, '']:
+            self.has_cache = False
+            logger.info("Not using a cache. "
+                        "Set CACHE = <directory> to enable.")
+            return
+
+        self.has_cache = True
+        self.cachefile = getCacheFile(self.cachedir, "bb_cache.dat", self.data_hash)
+
+        logger.debug(1, "Using cache in '%s'", self.cachedir)
+        bb.utils.mkdirhier(self.cachedir)
+
+        cache_ok = True
+        if self.caches_array:
+            for cache_class in self.caches_array:
+                if type(cache_class) is type and issubclass(cache_class, RecipeInfoCommon):
+                    cachefile = getCacheFile(self.cachedir, cache_class.cachefile, self.data_hash)
+                    cache_ok = cache_ok and os.path.exists(cachefile)
+                    cache_class.init_cacheData(self)
+        if cache_ok:
+            self.load_cachefile()
+        elif os.path.isfile(self.cachefile):
+            logger.info("Out of date cache found, rebuilding...")
+
+    def load_cachefile(self):
+        # Firstly, using core cache file information for
+        # valid checking
+        with open(self.cachefile, "rb") as cachefile:
+            pickled = pickle.Unpickler(cachefile)
+            try:
+                cache_ver = pickled.load()
+                bitbake_ver = pickled.load()
+            except Exception:
+                logger.info('Invalid cache, rebuilding...')
+                return
+
+            if cache_ver != __cache_version__:
+                logger.info('Cache version mismatch, rebuilding...')
+                return
+            elif bitbake_ver != bb.__version__:
+                logger.info('Bitbake version mismatch, rebuilding...')
+                return
+
+
+        cachesize = 0
+        previous_progress = 0
+        previous_percent = 0
+
+        # Calculate the correct cachesize of all those cache files
+        for cache_class in self.caches_array:
+            if type(cache_class) is type and issubclass(cache_class, RecipeInfoCommon):
+                cachefile = getCacheFile(self.cachedir, cache_class.cachefile, self.data_hash)
+                with open(cachefile, "rb") as cachefile:
+                    cachesize += os.fstat(cachefile.fileno()).st_size
+
+        bb.event.fire(bb.event.CacheLoadStarted(cachesize), self.data)
+        
+        for cache_class in self.caches_array:
+            if type(cache_class) is type and issubclass(cache_class, RecipeInfoCommon):
+                cachefile = getCacheFile(self.cachedir, cache_class.cachefile, self.data_hash)
+                with open(cachefile, "rb") as cachefile:
+                    pickled = pickle.Unpickler(cachefile)                    
+                    while cachefile:
+                        try:
+                            key = pickled.load()
+                            value = pickled.load()
+                        except Exception:
+                            break
+                        if self.depends_cache.has_key(key):
+                            self.depends_cache[key].append(value)
+                        else:
+                            self.depends_cache[key] = [value]
+                        # only fire events on even percentage boundaries
+                        current_progress = cachefile.tell() + previous_progress
+                        current_percent = 100 * current_progress / cachesize
+                        if current_percent > previous_percent:
+                            previous_percent = current_percent
+                            bb.event.fire(bb.event.CacheLoadProgress(current_progress, cachesize),
+                                          self.data)
+
+                    previous_progress += current_progress
+
+        # Note: depends cache number is corresponding to the parsing file numbers.
+        # The same file has several caches, still regarded as one item in the cache
+        bb.event.fire(bb.event.CacheLoadCompleted(cachesize,
+                                                  len(self.depends_cache)),
+                      self.data)
+
+    
+    @staticmethod
+    def virtualfn2realfn(virtualfn):
+        """
+        Convert a virtual file name to a real one + the associated subclass keyword
+        """
+
+        fn = virtualfn
+        cls = ""
+        if virtualfn.startswith('virtual:'):
+            elems = virtualfn.split(':')
+            cls = ":".join(elems[1:-1])
+            fn = elems[-1]
+        return (fn, cls)
+
+    @staticmethod
+    def realfn2virtual(realfn, cls):
+        """
+        Convert a real filename + the associated subclass keyword to a virtual filename
+        """
+        if cls == "":
+            return realfn
+        return "virtual:" + cls + ":" + realfn
+
+    @classmethod
+    def loadDataFull(cls, virtualfn, appends, cfgData):
+        """
+        Return a complete set of data for fn.
+        To do this, we need to parse the file.
+        """
+
+        (fn, virtual) = cls.virtualfn2realfn(virtualfn)
+
+        logger.debug(1, "Parsing %s (full)", fn)
+
+        cfgData.setVar("__ONLYFINALISE", virtual or "default")
+        bb_data = cls.load_bbfile(fn, appends, cfgData)
+        return bb_data[virtual]
+
+    @classmethod
+    def parse(cls, filename, appends, configdata, caches_array):
+        """Parse the specified filename, returning the recipe information"""
+        infos = []
+        datastores = cls.load_bbfile(filename, appends, configdata)
+        depends = []
+        for variant, data in sorted(datastores.iteritems(),
+                                    key=lambda i: i[0],
+                                    reverse=True):
+            virtualfn = cls.realfn2virtual(filename, variant)
+            depends = depends + (data.getVar("__depends", False) or [])
+            if depends and not variant:
+                data.setVar("__depends", depends)
+
+            info_array = []
+            for cache_class in caches_array:
+                if type(cache_class) is type and issubclass(cache_class, RecipeInfoCommon):
+                    info = cache_class(filename, data)
+                    info_array.append(info)
+            infos.append((virtualfn, info_array))
+
+        return infos
+
+    def load(self, filename, appends, configdata):
+        """Obtain the recipe information for the specified filename,
+        using cached values if available, otherwise parsing.
+
+        Note that if it does parse to obtain the info, it will not
+        automatically add the information to the cache or to your
+        CacheData.  Use the add or add_info method to do so after
+        running this, or use loadData instead."""
+        cached = self.cacheValid(filename, appends)
+        if cached:
+            infos = []
+            # info_array item is a list of [CoreRecipeInfo, XXXRecipeInfo]
+            info_array = self.depends_cache[filename]
+            for variant in info_array[0].variants:
+                virtualfn = self.realfn2virtual(filename, variant)
+                infos.append((virtualfn, self.depends_cache[virtualfn]))
+        else:
+            logger.debug(1, "Parsing %s", filename)
+            return self.parse(filename, appends, configdata, self.caches_array)
+
+        return cached, infos
+
+    def loadData(self, fn, appends, cfgData, cacheData):
+        """Load the recipe info for the specified filename,
+        parsing and adding to the cache if necessary, and adding
+        the recipe information to the supplied CacheData instance."""
+        skipped, virtuals = 0, 0
+
+        cached, infos = self.load(fn, appends, cfgData)
+        for virtualfn, info_array in infos:
+            if info_array[0].skipped:
+                logger.debug(1, "Skipping %s: %s", virtualfn, info_array[0].skipreason)
+                skipped += 1
+            else:
+                self.add_info(virtualfn, info_array, cacheData, not cached)
+                virtuals += 1
+
+        return cached, skipped, virtuals
+
+    def cacheValid(self, fn, appends):
+        """
+        Is the cache valid for fn?
+        Fast version, no timestamps checked.
+        """
+        if fn not in self.checked:
+            self.cacheValidUpdate(fn, appends)
+
+        # Is cache enabled?
+        if not self.has_cache:
+            return False
+        if fn in self.clean:
+            return True
+        return False
+
+    def cacheValidUpdate(self, fn, appends):
+        """
+        Is the cache valid for fn?
+        Make thorough (slower) checks including timestamps.
+        """
+        # Is cache enabled?
+        if not self.has_cache:
+            return False
+
+        self.checked.add(fn)
+
+        # File isn't in depends_cache
+        if not fn in self.depends_cache:
+            logger.debug(2, "Cache: %s is not cached", fn)
+            return False
+
+        mtime = bb.parse.cached_mtime_noerror(fn)
+
+        # Check file still exists
+        if mtime == 0:
+            logger.debug(2, "Cache: %s no longer exists", fn)
+            self.remove(fn)
+            return False
+
+        info_array = self.depends_cache[fn]
+        # Check the file's timestamp
+        if mtime != info_array[0].timestamp:
+            logger.debug(2, "Cache: %s changed", fn)
+            self.remove(fn)
+            return False
+
+        # Check dependencies are still valid
+        depends = info_array[0].file_depends
+        if depends:
+            for f, old_mtime in depends:
+                fmtime = bb.parse.cached_mtime_noerror(f)
+                # Check if file still exists
+                if old_mtime != 0 and fmtime == 0:
+                    logger.debug(2, "Cache: %s's dependency %s was removed",
+                                    fn, f)
+                    self.remove(fn)
+                    return False
+
+                if (fmtime != old_mtime):
+                    logger.debug(2, "Cache: %s's dependency %s changed",
+                                    fn, f)
+                    self.remove(fn)
+                    return False
+
+        if hasattr(info_array[0], 'file_checksums'):
+            for _, fl in info_array[0].file_checksums.items():
+                for f in fl.split():
+                    if "*" in f:
+                        continue
+                    f, exist = f.split(":")
+                    if (exist == "True" and not os.path.exists(f)) or (exist == "False" and os.path.exists(f)):
+                        logger.debug(2, "Cache: %s's file checksum list file %s changed",
+                                        fn, f)
+                        self.remove(fn)
+                        return False
+
+        if appends != info_array[0].appends:
+            logger.debug(2, "Cache: appends for %s changed", fn)
+            logger.debug(2, "%s to %s" % (str(appends), str(info_array[0].appends)))
+            self.remove(fn)
+            return False
+
+        invalid = False
+        for cls in info_array[0].variants:
+            virtualfn = self.realfn2virtual(fn, cls)
+            self.clean.add(virtualfn)
+            if virtualfn not in self.depends_cache:
+                logger.debug(2, "Cache: %s is not cached", virtualfn)
+                invalid = True
+
+        # If any one of the variants is not present, mark as invalid for all
+        if invalid:
+            for cls in info_array[0].variants:
+                virtualfn = self.realfn2virtual(fn, cls)
+                if virtualfn in self.clean:
+                    logger.debug(2, "Cache: Removing %s from cache", virtualfn)
+                    self.clean.remove(virtualfn)
+            if fn in self.clean:
+                logger.debug(2, "Cache: Marking %s as not clean", fn)
+                self.clean.remove(fn)
+            return False
+
+        self.clean.add(fn)
+        return True
+
+    def remove(self, fn):
+        """
+        Remove a fn from the cache
+        Called from the parser in error cases
+        """
+        if fn in self.depends_cache:
+            logger.debug(1, "Removing %s from cache", fn)
+            del self.depends_cache[fn]
+        if fn in self.clean:
+            logger.debug(1, "Marking %s as unclean", fn)
+            self.clean.remove(fn)
+
+    def sync(self):
+        """
+        Save the cache
+        Called from the parser when complete (or exiting)
+        """
+
+        if not self.has_cache:
+            return
+
+        if self.cacheclean:
+            logger.debug(2, "Cache is clean, not saving.")
+            return
+
+        file_dict = {}
+        pickler_dict = {}
+        for cache_class in self.caches_array:
+            if type(cache_class) is type and issubclass(cache_class, RecipeInfoCommon):
+                cache_class_name = cache_class.__name__
+                cachefile = getCacheFile(self.cachedir, cache_class.cachefile, self.data_hash)
+                file_dict[cache_class_name] = open(cachefile, "wb")
+                pickler_dict[cache_class_name] =  pickle.Pickler(file_dict[cache_class_name], pickle.HIGHEST_PROTOCOL)
+                   
+        pickler_dict['CoreRecipeInfo'].dump(__cache_version__)
+        pickler_dict['CoreRecipeInfo'].dump(bb.__version__)
+
+        try:
+            for key, info_array in self.depends_cache.iteritems():
+                for info in info_array:
+                    if isinstance(info, RecipeInfoCommon):
+                        cache_class_name = info.__class__.__name__
+                        pickler_dict[cache_class_name].dump(key)
+                        pickler_dict[cache_class_name].dump(info)
+        finally:
+            for cache_class in self.caches_array:
+                if type(cache_class) is type and issubclass(cache_class, RecipeInfoCommon):
+                    cache_class_name = cache_class.__name__
+                    file_dict[cache_class_name].close()
+
+        del self.depends_cache
+
+    @staticmethod
+    def mtime(cachefile):
+        return bb.parse.cached_mtime_noerror(cachefile)
+
+    def add_info(self, filename, info_array, cacheData, parsed=None, watcher=None):
+        if isinstance(info_array[0], CoreRecipeInfo) and (not info_array[0].skipped):
+            cacheData.add_from_recipeinfo(filename, info_array)
+
+            if watcher:
+                watcher(info_array[0].file_depends)
+
+        if not self.has_cache:
+            return
+
+        if (info_array[0].skipped or 'SRCREVINACTION' not in info_array[0].pv) and not info_array[0].nocache:
+            if parsed:
+                self.cacheclean = False
+            self.depends_cache[filename] = info_array
+
+    def add(self, file_name, data, cacheData, parsed=None):
+        """
+        Save data we need into the cache
+        """
+
+        realfn = self.virtualfn2realfn(file_name)[0]
+
+        info_array = []
+        for cache_class in self.caches_array:
+            if type(cache_class) is type and issubclass(cache_class, RecipeInfoCommon):
+                info_array.append(cache_class(realfn, data))
+        self.add_info(file_name, info_array, cacheData, parsed)
+
+    @staticmethod
+    def load_bbfile(bbfile, appends, config):
+        """
+        Load and parse one .bb build file
+        Return the data and whether parsing resulted in the file being skipped
+        """
+        chdir_back = False
+
+        from bb import parse
+
+        # expand tmpdir to include this topdir
+        config.setVar('TMPDIR', config.getVar('TMPDIR', True) or "")
+        bbfile_loc = os.path.abspath(os.path.dirname(bbfile))
+        oldpath = os.path.abspath(os.getcwd())
+        parse.cached_mtime_noerror(bbfile_loc)
+        bb_data = config.createCopy()
+        # The ConfHandler first looks if there is a TOPDIR and if not
+        # then it would call getcwd().
+        # Previously, we chdir()ed to bbfile_loc, called the handler
+        # and finally chdir()ed back, a couple of thousand times. We now
+        # just fill in TOPDIR to point to bbfile_loc if there is no TOPDIR yet.
+        if not bb_data.getVar('TOPDIR', False):
+            chdir_back = True
+            bb_data.setVar('TOPDIR', bbfile_loc)
+        try:
+            if appends:
+                bb_data.setVar('__BBAPPEND', " ".join(appends))
+            bb_data = parse.handle(bbfile, bb_data)
+            if chdir_back:
+                os.chdir(oldpath)
+            return bb_data
+        except:
+            if chdir_back:
+                os.chdir(oldpath)
+            raise
+
+
+def init(cooker):
+    """
+    The Objective: Cache the minimum amount of data possible yet get to the
+    stage of building packages (i.e. tryBuild) without reparsing any .bb files.
+
+    To do this, we intercept getVar calls and only cache the variables we see
+    being accessed. We rely on the cache getVar calls being made for all
+    variables bitbake might need to use to reach this stage. For each cached
+    file we need to track:
+
+    * Its mtime
+    * The mtimes of all its dependencies
+    * Whether it caused a parse.SkipRecipe exception
+
+    Files causing parsing errors are evicted from the cache.
+
+    """
+    return Cache(cooker.configuration.data, cooker.configuration.data_hash)
+
+
+class CacheData(object):
+    """
+    The data structures we compile from the cached data
+    """
+
+    def __init__(self, caches_array):
+        self.caches_array = caches_array
+        for cache_class in self.caches_array:
+            if type(cache_class) is type and issubclass(cache_class, RecipeInfoCommon):
+                cache_class.init_cacheData(self)        
+
+        # Direct cache variables
+        self.task_queues = {}
+        self.preferred = {}
+        self.tasks = {}
+        # Indirect Cache variables (set elsewhere)
+        self.ignored_dependencies = []
+        self.world_target = set()
+        self.bbfile_priority = {}
+
+    def add_from_recipeinfo(self, fn, info_array):
+        for info in info_array:
+            info.add_cacheData(self, fn)
+
+class MultiProcessCache(object):
+    """
+    BitBake multi-process cache implementation
+
+    Used by the codeparser & file checksum caches
+    """
+
+    def __init__(self):
+        self.cachefile = None
+        self.cachedata = self.create_cachedata()
+        self.cachedata_extras = self.create_cachedata()
+
+    def init_cache(self, d):
+        cachedir = (d.getVar("PERSISTENT_DIR", True) or
+                    d.getVar("CACHE", True))
+        if cachedir in [None, '']:
+            return
+        bb.utils.mkdirhier(cachedir)
+        self.cachefile = os.path.join(cachedir, self.__class__.cache_file_name)
+        logger.debug(1, "Using cache in '%s'", self.cachefile)
+
+        glf = bb.utils.lockfile(self.cachefile + ".lock")
+
+        try:
+            with open(self.cachefile, "rb") as f:
+                p = pickle.Unpickler(f)
+                data, version = p.load()
+        except:
+            bb.utils.unlockfile(glf)
+            return
+
+        bb.utils.unlockfile(glf)
+
+        if version != self.__class__.CACHE_VERSION:
+            return
+
+        self.cachedata = data
+
+    def create_cachedata(self):
+        data = [{}]
+        return data
+
+    def save_extras(self, d):
+        if not self.cachefile:
+            return
+
+        glf = bb.utils.lockfile(self.cachefile + ".lock", shared=True)
+
+        i = os.getpid()
+        lf = None
+        while not lf:
+            lf = bb.utils.lockfile(self.cachefile + ".lock." + str(i), retry=False)
+            if not lf or os.path.exists(self.cachefile + "-" + str(i)):
+                if lf:
+                    bb.utils.unlockfile(lf)
+                    lf = None
+                i = i + 1
+                continue
+
+            with open(self.cachefile + "-" + str(i), "wb") as f:
+                p = pickle.Pickler(f, -1)
+                p.dump([self.cachedata_extras, self.__class__.CACHE_VERSION])
+
+        bb.utils.unlockfile(lf)
+        bb.utils.unlockfile(glf)
+
+    def merge_data(self, source, dest):
+        for j in range(0,len(dest)):
+            for h in source[j]:
+                if h not in dest[j]:
+                    dest[j][h] = source[j][h]
+
+    def save_merge(self, d):
+        if not self.cachefile:
+            return
+
+        glf = bb.utils.lockfile(self.cachefile + ".lock")
+
+        data = self.cachedata
+
+        for f in [y for y in os.listdir(os.path.dirname(self.cachefile)) if y.startswith(os.path.basename(self.cachefile) + '-')]:
+            f = os.path.join(os.path.dirname(self.cachefile), f)
+            try:
+                with open(f, "rb") as fd:
+                    p = pickle.Unpickler(fd)
+                    extradata, version = p.load()
+            except (IOError, EOFError):
+                os.unlink(f)
+                continue
+
+            if version != self.__class__.CACHE_VERSION:
+                os.unlink(f)
+                continue
+
+            self.merge_data(extradata, data)
+            os.unlink(f)
+
+        with open(self.cachefile, "wb") as f:
+            p = pickle.Pickler(f, -1)
+            p.dump([data, self.__class__.CACHE_VERSION])
+
+        bb.utils.unlockfile(glf)
+