bitbake: layerindexlib: Initial layer index processing module implementation

The layer index module is expected to be used by various parts of the system
in order to access a layerindex-web (such as layers.openembedded.org) and
perform basic processing on the information, such as dependency scanning.

Along with the layerindex implementation are associated tests.  The tests
properly honor BB_SKIP_NETTESTS='yes' to prevent test failures.

Tests Implemented:
   - Branch, LayerItem, LayerBranch, LayerDependency, Recipe, Machine and
      Distro objects
   - LayerIndex setup using the layers.openembedded.org restapi
   - LayerIndex storing and retrieving from a file
   - LayerIndex verify dependency resolution ordering
   - LayerIndex setup using simulated cooker data

(Bitbake rev: fd0ee6c10dbb5592731e56f4c592fe687682a3e6)

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 1364 insertions, 0 deletions

diff --git a/bitbake/lib/layerindexlib/__init__.py b/bitbake/lib/layerindexlib/__init__.py
new file mode 100644
index 0000000000..74f3e2e93e
--- /dev/null
+++ b/bitbake/lib/layerindexlib/__init__.py
@@ -0,0 +1,1364 @@
+# Copyright (C) 2016-2018 Wind River Systems, Inc.
+#
+# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+import datetime
+
+import logging
+import imp
+
+from collections import OrderedDict
+from layerindexlib.plugin import LayerIndexPluginUrlError
+
+logger = logging.getLogger('BitBake.layerindexlib')
+
+# Exceptions
+
+class LayerIndexException(Exception):
+    '''LayerIndex Generic Exception'''
+    def __init__(self, message):
+         self.msg = message
+         Exception.__init__(self, message)
+
+    def __str__(self):
+         return self.msg
+
+class LayerIndexUrlError(LayerIndexException):
+    '''Exception raised when unable to access a URL for some reason'''
+    def __init__(self, url, message=""):
+        if message:
+            msg = "Unable to access layerindex url %s: %s" % (url, message)
+        else:
+            msg = "Unable to access layerindex url %s" % url
+        self.url = url
+        LayerIndexException.__init__(self, msg)
+
+class LayerIndexFetchError(LayerIndexException):
+    '''General layerindex fetcher exception when something fails'''
+    def __init__(self, url, message=""):
+        if message:
+            msg = "Unable to fetch layerindex url %s: %s" % (url, message)
+        else:
+            msg = "Unable to fetch layerindex url %s" % url
+        self.url = url
+        LayerIndexException.__init__(self, msg)
+
+
+# Interface to the overall layerindex system
+# the layer may contain one or more individual indexes
+class LayerIndex():
+    def __init__(self, d):
+        if not d:
+            raise LayerIndexException("Must be initialized with bb.data.")
+
+        self.data = d
+
+        # List of LayerIndexObj
+        self.indexes = []
+
+        self.plugins = []
+
+        import bb.utils
+        bb.utils.load_plugins(logger, self.plugins, os.path.dirname(__file__))
+        for plugin in self.plugins:
+            if hasattr(plugin, 'init'):
+                plugin.init(self)
+
+    def __add__(self, other):
+        newIndex = LayerIndex(self.data)
+
+        if self.__class__ != newIndex.__class__ or \
+           other.__class__ != newIndex.__class__:
+            raise TypeException("Can not add different types.")
+
+        for indexEnt in self.indexes:
+            newIndex.indexes.append(indexEnt)
+
+        for indexEnt in other.indexes:
+            newIndex.indexes.append(indexEnt)
+
+        return newIndex
+
+    def _parse_params(self, params):
+        '''Take a parameter list, return a dictionary of parameters.
+
+           Expected to be called from the data of urllib.parse.urlparse(url).params
+
+           If there are two conflicting parameters, last in wins...
+        '''
+
+        param_dict = {}
+        for param in params.split(';'):
+           if not param:
+               continue
+           item = param.split('=', 1)
+           logger.debug(1, item)
+           param_dict[item[0]] = item[1]
+
+        return param_dict
+
+    def _fetch_url(self, url, username=None, password=None, debuglevel=0):
+        '''Fetch data from a specific URL.
+
+           Fetch something from a specific URL.  This is specifically designed to
+           fetch data from a layerindex-web instance, but may be useful for other
+           raw fetch actions.
+
+           It is not designed to be used to fetch recipe sources or similar.  the
+           regular fetcher class should used for that.
+
+           It is the responsibility of the caller to check BB_NO_NETWORK and related
+           BB_ALLOWED_NETWORKS.
+        '''
+
+        if not url:
+            raise LayerIndexUrlError(url, "empty url")
+
+        import urllib
+        from urllib.request import urlopen, Request
+        from urllib.parse import urlparse
+
+        up = urlparse(url)
+
+        if username:
+            logger.debug(1, "Configuring authentication for %s..." % url)
+            password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()
+            password_mgr.add_password(None, "%s://%s" % (up.scheme, up.netloc), username, password)
+            handler = urllib.request.HTTPBasicAuthHandler(password_mgr)
+            opener = urllib.request.build_opener(handler, urllib.request.HTTPSHandler(debuglevel=debuglevel))
+        else:
+            opener = urllib.request.build_opener(urllib.request.HTTPSHandler(debuglevel=debuglevel))
+
+        urllib.request.install_opener(opener)
+
+        logger.debug(1, "Fetching %s (%s)..." % (url, ["without authentication", "with authentication"][bool(username)]))
+
+        try:
+            res = urlopen(Request(url, headers={'User-Agent': 'Mozilla/5.0 (bitbake/lib/layerindex)'}, unverifiable=True))
+        except urllib.error.HTTPError as e:
+            logger.debug(1, "HTTP Error: %s: %s" % (e.code, e.reason))
+            logger.debug(1, " Requested: %s" % (url))
+            logger.debug(1, " Actual:    %s" % (e.geturl()))
+
+            if e.code == 404:
+                logger.debug(1, "Request not found.")
+                raise LayerIndexFetchError(url, e)
+            else:
+                logger.debug(1, "Headers:\n%s" % (e.headers))
+                raise LayerIndexFetchError(url, e)
+        except OSError as e:
+            error = 0
+            reason = ""
+
+            # Process base OSError first...
+            if hasattr(e, 'errno'):
+                error = e.errno
+                reason = e.strerror
+
+            # Process gaierror (socket error) subclass if available.
+            if hasattr(e, 'reason') and hasattr(e.reason, 'errno') and hasattr(e.reason, 'strerror'):
+                error = e.reason.errno
+                reason = e.reason.strerror
+                if error == -2:
+                    raise LayerIndexFetchError(url, "%s: %s" % (e, reason))
+
+            if error and error != 0:
+                raise LayerIndexFetchError(url, "Unexpected exception: [Error %s] %s" % (error, reason))
+            else:
+                raise LayerIndexFetchError(url, "Unable to fetch OSError exception: %s" % e)
+
+        finally:
+            logger.debug(1, "...fetching %s (%s), done." % (url, ["without authentication", "with authentication"][bool(username)]))
+
+        return res
+
+
+    def load_layerindex(self, indexURI, load=['layerDependencies', 'recipes', 'machines', 'distros'], reload=False):
+        '''Load the layerindex.
+
+           indexURI - An index to load.  (Use multiple calls to load multiple indexes)
+           
+           reload - If reload is True, then any previously loaded indexes will be forgotten.
+           
+           load - List of elements to load.  Default loads all items.
+                  Note: plugs may ignore this.
+
+The format of the indexURI:
+
+  <url>;branch=<branch>;cache=<cache>;desc=<description>
+
+  Note: the 'branch' parameter if set can select multiple branches by using
+  comma, such as 'branch=master,morty,pyro'.  However, many operations only look
+  at the -first- branch specified!
+
+  The cache value may be undefined, in this case a network failure will
+  result in an error, otherwise the system will look for a file of the cache
+  name and load that instead.
+
+  For example:
+
+  http://layers.openembedded.org/layerindex/api/;branch=master;desc=OpenEmbedded%20Layer%20Index
+  cooker://
+'''
+        if reload:
+            self.indexes = []
+
+        logger.debug(1, 'Loading: %s' % indexURI)
+
+        if not self.plugins:
+            raise LayerIndexException("No LayerIndex Plugins available")
+
+        for plugin in self.plugins:
+            # Check if the plugin was initialized
+            logger.debug(1, 'Trying %s' % plugin.__class__)
+            if not hasattr(plugin, 'type') or not plugin.type:
+                continue
+            try:
+                # TODO: Implement 'cache', for when the network is not available
+                indexEnt = plugin.load_index(indexURI, load)
+                break
+            except LayerIndexPluginUrlError as e:
+                logger.debug(1, "%s doesn't support %s" % (plugin.type, e.url))
+            except NotImplementedError:
+                pass
+        else:
+            logger.debug(1, "No plugins support %s" % indexURI)
+            raise LayerIndexException("No plugins support %s" % indexURI)
+
+        # Mark CONFIG data as something we've added...
+        indexEnt.config['local'] = []
+        indexEnt.config['local'].append('config')
+
+        # No longer permit changes..
+        indexEnt.lockData()
+
+        self.indexes.append(indexEnt)
+
+    def store_layerindex(self, indexURI, index=None):
+        '''Store one layerindex
+
+Typically this will be used to create a local cache file of a remote index.
+
+  file://<path>;branch=<branch>
+
+We can write out in either the restapi or django formats.  The split option
+will write out the individual elements split by layer and related components.
+'''
+        if not index:
+            logger.warning('No index to write, nothing to do.')
+            return
+
+        if not self.plugins:
+            raise LayerIndexException("No LayerIndex Plugins available")
+
+        for plugin in self.plugins:
+            # Check if the plugin was initialized
+            logger.debug(1, 'Trying %s' % plugin.__class__)
+            if not hasattr(plugin, 'type') or not plugin.type:
+                continue
+            try:
+                plugin.store_index(indexURI, index)
+                break
+            except LayerIndexPluginUrlError as e:
+                logger.debug(1, "%s doesn't support %s" % (plugin.type, e.url))
+            except NotImplementedError:
+                logger.debug(1, "Store not implemented in %s" % plugin.type)
+                pass
+        else:
+            logger.debug(1, "No plugins support %s" % url)
+            raise LayerIndexException("No plugins support %s" % url)
+
+
+    def is_empty(self):
+        '''Return True or False if the index has any usable data.
+
+We check the indexes entries to see if they have a branch set, as well as
+layerBranches set.  If not, they are effectively blank.'''
+
+        found = False
+        for index in self.indexes:
+            if index.__bool__():
+                found = True
+                break
+        return not found
+
+
+    def find_vcs_url(self, vcs_url, branch=None):
+        '''Return the first layerBranch with the given vcs_url
+
+           If a branch has not been specified, we will iterate over the branches in
+           the default configuration until the first vcs_url/branch match.'''
+
+        for index in self.indexes:
+            logger.debug(1, ' searching %s' % index.config['DESCRIPTION'])
+            layerBranch = index.find_vcs_url(vcs_url, [branch])
+            if layerBranch:
+                return layerBranch
+        return None
+
+    def find_collection(self, collection, version=None, branch=None):
+        '''Return the first layerBranch with the given collection name
+
+           If a branch has not been specified, we will iterate over the branches in
+           the default configuration until the first collection/branch match.'''
+
+        logger.debug(1, 'find_collection: %s (%s) %s' % (collection, version, branch))
+
+        if branch:
+            branches = [branch]
+        else:
+            branches = None
+
+        for index in self.indexes:
+            logger.debug(1, ' searching %s' % index.config['DESCRIPTION'])
+            layerBranch = index.find_collection(collection, version, branches)
+            if layerBranch:
+                return layerBranch
+        else:
+            logger.debug(1, 'Collection %s (%s) not found for branch (%s)' % (collection, version, branch))
+        return None
+
+    def find_layerbranch(self, name, branch=None):
+        '''Return the layerBranch item for a given name and branch
+
+           If a branch has not been specified, we will iterate over the branches in
+           the default configuration until the first name/branch match.'''
+
+        if branch:
+            branches = [branch]
+        else:
+            branches = None
+
+        for index in self.indexes:
+            layerBranch = index.find_layerbranch(name, branches)
+            if layerBranch:
+                return layerBranch
+        return None
+
+    def find_dependencies(self, names=None, layerbranches=None, ignores=None):
+        '''Return a tuple of all dependencies and valid items for the list of (layer) names
+
+        The dependency scanning happens depth-first.  The returned
+        dependencies should be in the best order to define bblayers.
+
+          names - list of layer names (searching layerItems)
+          branches - when specified (with names) only this list of branches are evaluated
+
+          layerbranches - list of layerbranches to resolve dependencies
+
+          ignores - list of layer names to ignore
+
+        return: (dependencies, invalid)
+
+          dependencies[LayerItem.name] = [ LayerBranch, LayerDependency1, LayerDependency2, ... ]
+          invalid = [ LayerItem.name1, LayerItem.name2, ... ]
+        '''
+
+        invalid = []
+
+        # Convert name/branch to layerbranches
+        if layerbranches is None:
+            layerbranches = []
+
+        for name in names:
+            if ignores and name in ignores:
+                continue
+
+            for index in self.indexes:
+                layerbranch = index.find_layerbranch(name)
+                if not layerbranch:
+                    # Not in this index, hopefully it's in another...
+                    continue
+                layerbranches.append(layerbranch)
+                break
+            else:
+                invalid.append(name)
+
+
+        def _resolve_dependencies(layerbranches, ignores, dependencies, invalid):
+            for layerbranch in layerbranches:
+                if ignores and layerbranch.layer.name in ignores:
+                    continue
+
+                # Get a list of dependencies and then recursively process them
+                for layerdependency in layerbranch.index.layerDependencies_layerBranchId[layerbranch.id]:
+                    deplayerbranch = layerdependency.dependency_layerBranch
+
+                    if ignores and deplayerbranch.layer.name in ignores:
+                        continue
+
+                    # This little block is why we can't re-use the LayerIndexObj version,
+                    # we must be able to satisfy each dependencies across layer indexes and
+                    # use the layer index order for priority.  (r stands for replacement below)
+
+                    # If this is the primary index, we can fast path and skip this
+                    if deplayerbranch.index != self.indexes[0]:
+                        # Is there an entry in a prior index for this collection/version?
+                        rdeplayerbranch = self.find_collection(
+                                              collection=deplayerbranch.collection,
+                                              version=deplayerbranch.version
+                                          )
+                        if rdeplayerbranch != deplayerbranch:
+                                logger.debug(1, 'Replaced %s:%s:%s with %s:%s:%s' % \
+                                      (deplayerbranch.index.config['DESCRIPTION'],
+                                       deplayerbranch.branch.name,
+                                       deplayerbranch.layer.name,
+                                       rdeplayerbranch.index.config['DESCRIPTION'],
+                                       rdeplayerbranch.branch.name,
+                                       rdeplayerbranch.layer.name))
+                                deplayerbranch = rdeplayerbranch
+
+                    # New dependency, we need to resolve it now... depth-first
+                    if deplayerbranch.layer.name not in dependencies:
+                        (dependencies, invalid) = _resolve_dependencies([deplayerbranch], ignores, dependencies, invalid)
+
+                    if deplayerbranch.layer.name not in dependencies:
+                        dependencies[deplayerbranch.layer.name] = [deplayerbranch, layerdependency]
+                    else:
+                        if layerdependency not in dependencies[deplayerbranch.layer.name]:
+                            dependencies[deplayerbranch.layer.name].append(layerdependency)
+
+            return (dependencies, invalid)
+
+        # OK, resolve this one...
+        dependencies = OrderedDict()
+        (dependencies, invalid) = _resolve_dependencies(layerbranches, ignores, dependencies, invalid)
+
+        for layerbranch in layerbranches:
+            if layerbranch.layer.name not in dependencies:
+                dependencies[layerbranch.layer.name] = [layerbranch]
+
+        return (dependencies, invalid)
+
+
+    def list_obj(self, object):
+        '''Print via the plain logger object information
+
+This function is used to implement debugging and provide the user info.
+'''
+        for lix in self.indexes:
+            if object not in lix:
+                continue
+
+            logger.plain ('')
+            logger.plain ('Index: %s' % lix.config['DESCRIPTION'])
+
+            output = []
+
+            if object == 'branches':
+                logger.plain ('%s %s %s' % ('{:26}'.format('branch'), '{:34}'.format('description'), '{:22}'.format('bitbake branch')))
+                logger.plain ('{:-^80}'.format(""))
+                for branchid in lix.branches:
+                    output.append('%s %s %s' % (
+                                  '{:26}'.format(lix.branches[branchid].name),
+                                  '{:34}'.format(lix.branches[branchid].short_description),
+                                  '{:22}'.format(lix.branches[branchid].bitbake_branch)
+                                 ))
+                for line in sorted(output):
+                    logger.plain (line)
+
+                continue
+
+            if object == 'layerItems':
+                logger.plain ('%s %s' % ('{:26}'.format('layer'), '{:34}'.format('description')))
+                logger.plain ('{:-^80}'.format(""))
+                for layerid in lix.layerItems:
+                    output.append('%s %s' % (
+                                  '{:26}'.format(lix.layerItems[layerid].name),
+                                  '{:34}'.format(lix.layerItems[layerid].summary)
+                                 ))
+                for line in sorted(output):
+                    logger.plain (line)
+
+                continue
+
+            if object == 'layerBranches':
+                logger.plain ('%s %s %s' % ('{:26}'.format('layer'), '{:34}'.format('description'), '{:19}'.format('collection:version')))
+                logger.plain ('{:-^80}'.format(""))
+                for layerbranchid in lix.layerBranches:
+                    output.append('%s %s %s' % (
+                                  '{:26}'.format(lix.layerBranches[layerbranchid].layer.name),
+                                  '{:34}'.format(lix.layerBranches[layerbranchid].layer.summary),
+                                  '{:19}'.format("%s:%s" %
+                                                          (lix.layerBranches[layerbranchid].collection,
+                                                           lix.layerBranches[layerbranchid].version)
+                                                )
+                                 ))
+                for line in sorted(output):
+                    logger.plain (line)
+
+                continue
+
+            if object == 'layerDependencies':
+                logger.plain ('%s %s %s %s' % ('{:19}'.format('branch'), '{:26}'.format('layer'), '{:11}'.format('dependency'), '{:26}'.format('layer')))
+                logger.plain ('{:-^80}'.format(""))
+                for layerDependency in lix.layerDependencies:
+                    if not lix.layerDependencies[layerDependency].dependency_layerBranch:
+                        continue
+
+                    output.append('%s %s %s %s' % (
+                                  '{:19}'.format(lix.layerDependencies[layerDependency].layerbranch.branch.name),
+                                  '{:26}'.format(lix.layerDependencies[layerDependency].layerbranch.layer.name),
+                                  '{:11}'.format('requires' if lix.layerDependencies[layerDependency].required else 'recommends'),
+                                  '{:26}'.format(lix.layerDependencies[layerDependency].dependency_layerBranch.layer.name)
+                                 ))
+                for line in sorted(output):
+                    logger.plain (line)
+
+                continue
+
+            if object == 'recipes':
+                logger.plain ('%s %s %s' % ('{:20}'.format('recipe'), '{:10}'.format('version'), 'layer'))
+                logger.plain ('{:-^80}'.format(""))
+                output = []
+                for recipe in lix.recipes:
+                    output.append('%s %s %s' % (
+                                  '{:30}'.format(lix.recipes[recipe].pn),
+                                  '{:30}'.format(lix.recipes[recipe].pv),
+                                  lix.recipes[recipe].layer.name
+                                 ))
+                for line in sorted(output):
+                    logger.plain (line)
+
+                continue
+
+            if object == 'machines':
+                logger.plain ('%s %s %s' % ('{:24}'.format('machine'), '{:34}'.format('description'), '{:19}'.format('layer')))
+                logger.plain ('{:-^80}'.format(""))
+                for machine in lix.machines:
+                    output.append('%s %s %s' % (
+                                  '{:24}'.format(lix.machines[machine].name),
+                                  '{:34}'.format(lix.machines[machine].description)[:34],
+                                  '{:19}'.format(lix.machines[machine].layerbranch.layer.name)
+                                 ))
+                for line in sorted(output):
+                    logger.plain (line)
+
+                continue
+
+            if object == 'distros':
+                logger.plain ('%s %s %s' % ('{:24}'.format('distro'), '{:34}'.format('description'), '{:19}'.format('layer')))
+                logger.plain ('{:-^80}'.format(""))
+                for distro in lix.distros:
+                    output.append('%s %s %s' % (
+                                  '{:24}'.format(lix.distros[distro].name),
+                                  '{:34}'.format(lix.distros[distro].description)[:34],
+                                  '{:19}'.format(lix.distros[distro].layerbranch.layer.name)
+                                 ))
+                for line in sorted(output):
+                    logger.plain (line)
+
+                continue
+
+        logger.plain ('')
+
+
+# This class holds a single layer index instance
+# The LayerIndexObj is made up of dictionary of elements, such as:
+#   index['config'] - configuration data for this index
+#   index['branches'] - dictionary of Branch objects, by id number
+#   index['layerItems'] - dictionary of layerItem objects, by id number
+#   ...etc...  (See: http://layers.openembedded.org/layerindex/api/)
+#
+# The class needs to manage the 'index' entries and allow easily adding
+# of new items, as well as simply loading of the items.
+class LayerIndexObj():
+    def __init__(self):
+        super().__setattr__('_index', {})
+        super().__setattr__('_lock', False)
+
+    def __bool__(self):
+        '''False if the index is effectively empty
+
+           We check the index to see if it has a branch set, as well as
+           layerbranches set.  If not, it is effectively blank.'''
+
+        if not bool(self._index):
+            return False
+
+        try:
+            if self.branches and self.layerBranches:
+                return True
+        except AttributeError:
+            pass
+
+        return False
+
+    def __getattr__(self, name):
+        if name.startswith('_'):
+            return super().__getattribute__(name)
+
+        if name not in self._index:
+            raise AttributeError('%s not in index datastore' % name)
+
+        return self._index[name]
+
+    def __setattr__(self, name, value):
+        if self.isLocked():
+            raise TypeError("Can not set attribute '%s': index is locked" % name)
+
+        if name.startswith('_'):
+            super().__setattr__(name, value)
+            return
+
+        self._index[name] = value
+
+    def __delattr__(self, name):
+        if self.isLocked():
+            raise TypeError("Can not delete attribute '%s': index is locked" % name)
+
+        if name.startswith('_'):
+            super().__delattr__(name)
+
+        self._index.pop(name)
+
+    def lockData(self):
+        '''Lock data object (make it readonly)'''
+        super().__setattr__("_lock", True)
+
+    def unlockData(self):
+        '''unlock data object (make it readonly)'''
+        super().__setattr__("_lock", False)
+
+        # When the data is unlocked, we have to clear the caches, as
+        # modification is allowed!
+        del(self._layerBranches_layerId_branchId)
+        del(self._layerDependencies_layerBranchId)
+        del(self._layerBranches_vcsUrl)
+
+    def isLocked(self):
+        '''Is this object locked (readonly)?'''
+        return self._lock
+
+    def add_element(self, indexname, objs):
+        '''Add a layer index object to index.<indexname>'''
+        if indexname not in self._index:
+            self._index[indexname] = {}
+
+        for obj in objs:
+            if obj.id in self._index[indexname]:
+                if self._index[indexname][obj.id] == obj:
+                    continue
+                raise LayerIndexError('Conflict adding object %s(%s) to index' % (indexname, obj.id))
+            self._index[indexname][obj.id] = obj
+
+    def add_raw_element(self, indexname, objtype, rawobjs):
+        '''Convert a raw layer index data item to a layer index item object and add to the index'''
+        objs = []
+        for entry in rawobjs:
+            objs.append(objtype(self, entry))
+        self.add_element(indexname, objs)
+
+    # Quick lookup table for searching layerId and branchID combos
+    @property
+    def layerBranches_layerId_branchId(self):
+        def createCache(self):
+            cache = {}
+            for layerbranchid in self.layerBranches:
+                layerbranch = self.layerBranches[layerbranchid]
+                cache["%s:%s" % (layerbranch.layer_id, layerbranch.branch_id)] = layerbranch
+            return cache
+
+        if self.isLocked():
+            cache = getattr(self, '_layerBranches_layerId_branchId', None)
+        else:
+            cache = None
+
+        if not cache:
+            cache = createCache(self)
+
+        if self.isLocked():
+            super().__setattr__('_layerBranches_layerId_branchId', cache)
+
+        return cache
+
+    # Quick lookup table for finding all dependencies of a layerBranch
+    @property
+    def layerDependencies_layerBranchId(self):
+        def createCache(self):
+            cache = {}
+            # This ensures empty lists for all branchids
+            for layerbranchid in self.layerBranches:
+                cache[layerbranchid] = []
+
+            for layerdependencyid in self.layerDependencies:
+                layerdependency = self.layerDependencies[layerdependencyid]
+                cache[layerdependency.layerbranch_id].append(layerdependency)
+            return cache
+
+        if self.isLocked():
+            cache = getattr(self, '_layerDependencies_layerBranchId', None)
+        else:
+            cache = None
+
+        if not cache:
+            cache = createCache(self)
+
+        if self.isLocked():
+            super().__setattr__('_layerDependencies_layerBranchId', cache)
+
+        return cache
+
+    # Quick lookup table for finding all instances of a vcs_url
+    @property
+    def layerBranches_vcsUrl(self):
+        def createCache(self):
+            cache = {}
+            for layerbranchid in self.layerBranches:
+                layerbranch = self.layerBranches[layerbranchid]
+                if layerbranch.layer.vcs_url not in cache:
+                   cache[layerbranch.layer.vcs_url] = [layerbranch]
+                else:
+                   cache[layerbranch.layer.vcs_url].append(layerbranch)
+            return cache
+
+        if self.isLocked():
+            cache = getattr(self, '_layerBranches_vcsUrl', None)
+        else:
+            cache = None
+
+        if not cache:
+            cache = createCache(self)
+
+        if self.isLocked():
+            super().__setattr__('_layerBranches_vcsUrl', cache)
+
+        return cache
+
+
+    def find_vcs_url(self, vcs_url, branches=None):
+        ''''Return the first layerBranch with the given vcs_url
+
+            If a list of branches has not been specified, we will iterate on
+            all branches until the first vcs_url is found.'''
+
+        if not self.__bool__():
+            return None
+
+        for layerbranch in self.layerBranches_vcsUrl:
+            if branches and layerbranch.branch.name not in branches:
+                continue
+
+            return layerbranch
+
+        return None
+
+
+    def find_collection(self, collection, version=None, branches=None):
+        '''Return the first layerBranch with the given collection name
+
+           If a list of branches has not been specified, we will iterate on
+           all branches until the first collection is found.'''
+
+        if not self.__bool__():
+            return None
+
+        for layerbranchid in self.layerBranches:
+            layerbranch = self.layerBranches[layerbranchid]
+            if branches and layerbranch.branch.name not in branches:
+                continue
+
+            if layerbranch.collection == collection and \
+                (version is None or version == layerbranch.version):
+                return layerbranch
+
+        return None
+
+
+    def find_layerbranch(self, name, branches=None):
+        '''Return the first layerbranch whose layer name matches
+
+           If a list of branches has not been specified, we will iterate on
+           all branches until the first layer with that name is found.'''
+
+        if not self.__bool__():
+            return None
+
+        for layerbranchid in self.layerBranches:
+            layerbranch = self.layerBranches[layerbranchid]
+            if branches and layerbranch.branch.name not in branches:
+                continue
+
+            if layerbranch.layer.name == name:
+                return layerbranch
+
+        return None
+
+    def find_dependencies(self, names=None, branches=None, layerBranches=None, ignores=None):
+        '''Return a tuple of all dependencies and valid items for the list of (layer) names
+
+        The dependency scanning happens depth-first.  The returned
+        dependencies should be in the best order to define bblayers.
+
+          names - list of layer names (searching layerItems)
+          branches - when specified (with names) only this list of branches are evaluated
+
+          layerBranches - list of layerBranches to resolve dependencies
+
+          ignores - list of layer names to ignore
+
+        return: (dependencies, invalid)
+
+          dependencies[LayerItem.name] = [ LayerBranch, LayerDependency1, LayerDependency2, ... ]
+          invalid = [ LayerItem.name1, LayerItem.name2, ... ]'''
+
+        invalid = []
+
+        # Convert name/branch to layerBranches
+        if layerbranches is None:
+            layerbranches = []
+
+        for name in names:
+            if ignores and name in ignores:
+                continue
+
+            layerbranch = self.find_layerbranch(name, branches)
+            if not layerbranch:
+                invalid.append(name)
+            else:
+                layerbranches.append(layerbranch)
+
+        for layerbranch in layerbranches:
+            if layerbranch.index != self:
+                raise LayerIndexException("Can not resolve dependencies across indexes with this class function!")
+
+        def _resolve_dependencies(layerbranches, ignores, dependencies, invalid):
+            for layerbranch in layerbranches:
+                if ignores and layerBranch.layer.name in ignores:
+                    continue
+
+                for layerdependency in layerbranch.index.layerDependencies_layerBranchId[layerBranch.id]:
+                    deplayerbranch = layerDependency.dependency_layerBranch
+
+                    if ignores and deplayerbranch.layer.name in ignores:
+                        continue
+
+                    # New dependency, we need to resolve it now... depth-first
+                    if deplayerbranch.layer.name not in dependencies:
+                        (dependencies, invalid) = _resolve_dependencies([deplayerbranch], ignores, dependencies, invalid)
+
+                    if deplayerbranch.layer.name not in dependencies:
+                        dependencies[deplayerbranch.layer.name] = [deplayerbranch, layerdependency]
+                    else:
+                        if layerdependency not in dependencies[deplayerbranch.layer.name]:
+                            dependencies[deplayerbranch.layer.name].append(layerdependency)
+
+                return (dependencies, invalid)
+
+        # OK, resolve this one...
+        dependencies = OrderedDict()
+        (dependencies, invalid) = _resolve_dependencies(layerbranches, ignores, dependencies, invalid)
+
+        # Is this item already in the list, if not add it
+        for layerbranch in layerbranches:
+            if layerbranch.layer.name not in dependencies:
+                dependencies[layerbranch.layer.name] = [layerbranch]
+
+        return (dependencies, invalid)
+
+
+# Define a basic LayerIndexItemObj.  This object forms the basis for all other
+# objects.  The raw Layer Index data is stored in the _data element, but we
+# do not want users to access data directly.  So wrap this and protect it
+# from direct manipulation.
+#
+# It is up to the insantiators of the objects to fill them out, and once done
+# lock the objects to prevent further accidently manipulation.
+#
+# Using the getattr, setattr and properties we can access and manipulate
+# the data within the data element.
+class LayerIndexItemObj():
+    def __init__(self, index, data=None, lock=False):
+        if data is None:
+            data = {}
+
+        if type(data) != type(dict()):
+            raise TypeError('data (%s) is not a dict' % type(data))
+
+        super().__setattr__('_lock',  lock)
+        super().__setattr__('index', index)
+        super().__setattr__('_data',  data)
+
+    def __eq__(self, other):
+        if self.__class__ != other.__class__:
+            return False
+        res=(self._data == other._data)
+        return res
+
+    def __bool__(self):
+        return bool(self._data)
+
+    def __getattr__(self, name):
+        # These are internal to THIS class, and not part of data
+        if name == "index" or name.startswith('_'):
+            return super().__getattribute__(name)
+
+        if name not in self._data:
+            raise AttributeError('%s not in datastore' % name)
+
+        return self._data[name]
+
+    def _setattr(self, name, value, prop=True):
+        '''__setattr__ like function, but with control over property object behavior'''
+        if self.isLocked():
+            raise TypeError("Can not set attribute '%s': Object data is locked" % name)
+
+        if name.startswith('_'):
+            super().__setattr__(name, value)
+            return
+
+        # Since __setattr__ runs before properties, we need to check if
+        # there is a setter property and then execute it
+        # ... or return self._data[name]
+        propertyobj = getattr(self.__class__, name, None)
+        if prop and isinstance(propertyobj, property):
+            if propertyobj.fset:
+                propertyobj.fset(self, value)
+            else:
+                raise AttributeError('Attribute %s is readonly, and may not be set' % name)
+        else:
+            self._data[name] = value
+
+    def __setattr__(self, name, value):
+        self._setattr(name, value, prop=True)
+
+    def _delattr(self, name, prop=True):
+        # Since __delattr__ runs before properties, we need to check if
+        # there is a deleter property and then execute it
+        # ... or we pop it ourselves..
+        propertyobj = getattr(self.__class__, name, None)
+        if prop and isinstance(propertyobj, property):
+            if propertyobj.fdel:
+                propertyobj.fdel(self)
+            else:
+                raise AttributeError('Attribute %s is readonly, and may not be deleted' % name)
+        else:
+            self._data.pop(name)
+
+    def __delattr__(self, name):
+        self._delattr(name, prop=True)
+
+    def lockData(self):
+        '''Lock data object (make it readonly)'''
+        super().__setattr__("_lock", True)
+
+    def unlockData(self):
+        '''unlock data object (make it readonly)'''
+        super().__setattr__("_lock", False)
+
+    def isLocked(self):
+        '''Is this object locked (readonly)?'''
+        return self._lock
+
+# Branch object
+class Branch(LayerIndexItemObj):
+    def define_data(self, id, name, bitbake_branch,
+                 short_description=None, sort_priority=1,
+                 updates_enabled=True, updated=None,
+                 update_environment=None):
+        self.id = id
+        self.name = name
+        self.bitbake_branch = bitbake_branch
+        self.short_description = short_description or name
+        self.sort_priority = sort_priority
+        self.updates_enabled = updates_enabled
+        self.updated = updated or datetime.datetime.today().isoformat()
+        self.update_environment = update_environment
+
+    @property
+    def name(self):
+        return self.__getattr__('name')
+
+    @name.setter
+    def name(self, value):
+        self._data['name'] = value
+
+        if self.bitbake_branch == value:
+            self.bitbake_branch = ""
+
+    @name.deleter
+    def name(self):
+        self._delattr('name', prop=False)
+
+    @property
+    def bitbake_branch(self):
+        try:
+            return self.__getattr__('bitbake_branch')
+        except AttributeError:
+            return self.name
+
+    @bitbake_branch.setter
+    def bitbake_branch(self, value):
+        if self.name == value:
+            self._data['bitbake_branch'] = ""
+        else:
+            self._data['bitbake_branch'] = value
+
+    @bitbake_branch.deleter
+    def bitbake_branch(self):
+        self._delattr('bitbake_branch', prop=False)
+
+
+class LayerItem(LayerIndexItemObj):
+    def define_data(self, id, name, status='P',
+                 layer_type='A', summary=None,
+                 description=None,
+                 vcs_url=None, vcs_web_url=None,
+                 vcs_web_tree_base_url=None,
+                 vcs_web_file_base_url=None,
+                 usage_url=None,
+                 mailing_list_url=None,
+                 index_preference=1,
+                 classic=False,
+                 updated=None):
+        self.id = id
+        self.name = name
+        self.status = status
+        self.layer_type = layer_type
+        self.summary = summary or name
+        self.description = description or summary or name
+        self.vcs_url = vcs_url
+        self.vcs_web_url = vcs_web_url
+        self.vcs_web_tree_base_url = vcs_web_tree_base_url
+        self.vcs_web_file_base_url = vcs_web_file_base_url
+        self.index_preference = index_preference
+        self.classic = classic
+        self.updated = updated or datetime.datetime.today().isoformat()
+
+
+class LayerBranch(LayerIndexItemObj):
+    def define_data(self, id, collection, version, layer, branch,
+                 vcs_subdir="", vcs_last_fetch=None,
+                 vcs_last_rev=None, vcs_last_commit=None,
+                 actual_branch="",
+                 updated=None):
+        self.id = id
+        self.collection = collection
+        self.version = version
+        if type(layer) != type(LayerItem):
+            self.layer_id = layer
+        else:
+            self.layer = layer
+
+        if type(branch) != type(Branch):
+            self.branch_id = branch
+        else:
+            self.branch = branch
+
+        self.vcs_subdir = vcs_subdir
+        self.vcs_last_fetch = vcs_last_fetch
+        self.vcs_last_rev = vcs_last_rev
+        self.vcs_last_commit = vcs_last_commit
+        self.actual_branch = actual_branch
+        self.updated = updated or datetime.datetime.today().isoformat()
+
+    # This is a little odd, the _data attribute is 'layer', but it's really
+    # referring to the layer id.. so lets adjust this to make it useful
+    @property
+    def layer_id(self):
+        return self.__getattr__('layer')
+
+    @layer_id.setter
+    def layer_id(self, value):
+        self._setattr('layer', value, prop=False)
+
+    @layer_id.deleter
+    def layer_id(self):
+        self._delattr('layer', prop=False)
+
+    @property
+    def layer(self):
+        try:
+            return self.index.layerItems[self.layer_id]
+        except KeyError:
+            raise AttributeError('Unable to find layerItems in index to map layer_id %s' % self.layer_id)
+        except IndexError:
+            raise AttributeError('Unable to find layer_id %s in index layerItems' % self.layer_id)
+
+    @layer.setter
+    def layer(self, value):
+        if type(value) != type(LayerItem):
+            raise TypeError('value is not a LayerItem')
+        if self.index != value.index:
+            raise AttributeError('Object and value do not share the same index and thus key set.')
+        self.layer_id = value.id
+
+    @layer.deleter
+    def layer(self):
+        del self.layer_id
+
+    @property
+    def branch_id(self):
+        return self.__getattr__('branch')
+
+    @branch_id.setter
+    def branch_id(self, value):
+        self._setattr('branch', value, prop=False)
+
+    @branch_id.deleter
+    def branch_id(self):
+        self._delattr('branch', prop=False)
+
+    @property
+    def branch(self):
+        try:
+            logger.debug(1, "Get branch object from branches[%s]" % (self.branch_id))
+            return self.index.branches[self.branch_id]
+        except KeyError:
+            raise AttributeError('Unable to find branches in index to map branch_id %s' % self.branch_id)
+        except IndexError:
+            raise AttributeError('Unable to find branch_id %s in index branches' % self.branch_id)
+
+    @branch.setter
+    def branch(self, value):
+        if type(value) != type(LayerItem):
+            raise TypeError('value is not a LayerItem')
+        if self.index != value.index:
+            raise AttributeError('Object and value do not share the same index and thus key set.')
+        self.branch_id = value.id
+
+    @branch.deleter
+    def branch(self):
+        del self.branch_id
+
+    @property
+    def actual_branch(self):
+        if self.__getattr__('actual_branch'):
+            return self.__getattr__('actual_branch')
+        else:
+            return self.branch.name
+
+    @actual_branch.setter
+    def actual_branch(self, value):
+        logger.debug(1, "Set actual_branch to %s .. name is %s" % (value, self.branch.name))
+        if value != self.branch.name:
+            self._setattr('actual_branch', value, prop=False)
+        else:
+            self._setattr('actual_branch', '', prop=False)
+
+    @actual_branch.deleter
+    def actual_branch(self):
+        self._delattr('actual_branch', prop=False)
+
+# Extend LayerIndexItemObj with common LayerBranch manipulations
+# All of the remaining LayerIndex objects refer to layerbranch, and it is
+# up to the user to follow that back through the LayerBranch object into
+# the layer object to get various attributes.  So add an intermediate set
+# of attributes that can easily get us the layerbranch as well as layer.
+
+class LayerIndexItemObj_LayerBranch(LayerIndexItemObj):
+    @property
+    def layerbranch_id(self):
+        return self.__getattr__('layerbranch')
+
+    @layerbranch_id.setter
+    def layerbranch_id(self, value):
+        self._setattr('layerbranch', value, prop=False)
+
+    @layerbranch_id.deleter
+    def layerbranch_id(self):
+        self._delattr('layerbranch', prop=False)
+
+    @property
+    def layerbranch(self):
+        try:
+            return self.index.layerBranches[self.layerbranch_id]
+        except KeyError:
+            raise AttributeError('Unable to find layerBranches in index to map layerbranch_id %s' % self.layerbranch_id)
+        except IndexError:
+            raise AttributeError('Unable to find layerbranch_id %s in index branches' % self.layerbranch_id)
+
+    @layerbranch.setter
+    def layerbranch(self, value):
+        if type(value) != type(LayerBranch):
+            raise TypeError('value (%s) is not a layerBranch' % type(value))
+        if self.index != value.index:
+            raise AttributeError('Object and value do not share the same index and thus key set.')
+        self.layerbranch_id = value.id
+
+    @layerbranch.deleter
+    def layerbranch(self):
+        del self.layerbranch_id
+
+    @property
+    def layer_id(self):
+        return self.layerbranch.layer_id
+
+    # Doesn't make sense to set or delete layer_id
+
+    @property
+    def layer(self):
+        return self.layerbranch.layer
+
+    # Doesn't make sense to set or delete layer
+
+
+class LayerDependency(LayerIndexItemObj_LayerBranch):
+    def define_data(self, id, layerbranch, dependency, required=True):
+        self.id = id
+        if type(layerbranch) != type(LayerBranch):
+            self.layerbranch_id = layerbranch
+        else:
+            self.layerbranch = layerbranch
+        if type(dependency) != type(LayerDependency):
+            self.dependency_id = dependency
+        else:
+            self.dependency = dependency
+        self.required = required
+
+    @property
+    def dependency_id(self):
+        return self.__getattr__('dependency')
+
+    @dependency_id.setter
+    def dependency_id(self, value):
+        self._setattr('dependency', value, prop=False)
+
+    @dependency_id.deleter
+    def dependency_id(self):
+        self._delattr('dependency', prop=False)
+
+    @property
+    def dependency(self):
+        try:
+            return self.index.layerItems[self.dependency_id]
+        except KeyError:
+            raise AttributeError('Unable to find layerItems in index to map layerbranch_id %s' % self.dependency_id)
+        except IndexError:
+            raise AttributeError('Unable to find dependency_id %s in index layerItems' % self.dependency_id)
+
+    @dependency.setter
+    def dependency(self, value):
+        if type(value) != type(LayerDependency):
+            raise TypeError('value (%s) is not a dependency' % type(value))
+        if self.index != value.index:
+            raise AttributeError('Object and value do not share the same index and thus key set.')
+        self.dependency_id = value.id
+
+    @dependency.deleter
+    def dependency(self):
+        self._delattr('dependency', prop=False)
+
+    @property
+    def dependency_layerBranch(self):
+        layerid = self.dependency_id
+        branchid = self.layerbranch.branch_id
+
+        try:
+            return self.index.layerBranches_layerId_branchId["%s:%s" % (layerid, branchid)]
+        except IndexError:
+            # layerBranches_layerId_branchId -- but not layerId:branchId
+            raise AttributeError('Unable to find layerId:branchId %s:%s in index layerBranches_layerId_branchId' % (layerid, branchid))
+        except KeyError:
+            raise AttributeError('Unable to find layerId:branchId %s:%s in layerItems and layerBranches' % (layerid, branchid))
+
+    # dependency_layerBranch doesn't make sense to set or del
+
+
+class Recipe(LayerIndexItemObj_LayerBranch):
+    def define_data(self, id,
+                    filename, filepath, pn, pv, layerbranch,
+                    summary="", description="", section="", license="",
+                    homepage="", bugtracker="", provides="", bbclassextend="",
+                    inherits="", blacklisted="", updated=None):
+        self.id = id
+        self.filename = filename
+        self.filepath = filepath
+        self.pn = pn
+        self.pv = pv
+        self.summary = summary
+        self.description = description
+        self.section = section
+        self.license = license
+        self.homepage = homepage
+        self.bugtracker = bugtracker
+        self.provides = provides
+        self.bbclassextend = bbclassextend
+        self.inherits = inherits
+        self.updated = updated or datetime.datetime.today().isoformat()
+        self.blacklisted = blacklisted
+        if type(layerbranch) != type(LayerBranch):
+            self.layerbranch_id = layerbranch
+        else:
+            self.layerbranch = layerbranch
+
+    @property
+    def fullpath(self):
+        return os.path.join(self.filepath, self.filename)
+
+    # Set would need to understand how to split it
+    # del would we del both parts?
+
+    @property
+    def inherits(self):
+        if 'inherits' not in self._data:
+            # Older indexes may not have this, so emulate it
+            if '-image-' in self.pn:
+                return 'image'
+        return self.__getattr__('inherits')
+
+    @inherits.setter
+    def inherits(self, value):
+        return self._setattr('inherits', value, prop=False)
+
+    @inherits.deleter
+    def inherits(self):
+        return self._delattr('inherits', prop=False)
+
+
+class Machine(LayerIndexItemObj_LayerBranch):
+    def define_data(self, id,
+                    name, description, layerbranch,
+                    updated=None):
+        self.id = id
+        self.name = name
+        self.description = description
+        if type(layerbranch) != type(LayerBranch):
+            self.layerbranch_id = layerbranch
+        else:
+            self.layerbranch = layerbranch
+        self.updated = updated or datetime.datetime.today().isoformat()
+
+class Distro(LayerIndexItemObj_LayerBranch):
+    def define_data(self, id,
+                    name, description, layerbranch,
+                    updated=None):
+        self.id = id
+        self.name = name
+        self.description = description
+        if type(layerbranch) != type(LayerBranch):
+            self.layerbranch_id = layerbranch
+        else:
+            self.layerbranch = layerbranch
+        self.updated = updated or datetime.datetime.today().isoformat()
+
+
+# When performing certain actions, we may need to sort the data.
+# This will allow us to keep it consistent from run to run.
+def sort_entry(item):
+    newitem = item
+    try:
+        if type(newitem) == type(dict()):
+            newitem = OrderedDict(sorted(newitem.items(), key=lambda t: t[0]))
+            for index in newitem:
+                newitem[index] = sort_entry(newitem[index])
+        elif type(newitem) == type(list()):
+            newitem.sort(key=lambda obj: obj['id'])
+            for index, _ in enumerate(newitem):
+                newitem[index] = sort_entry(newitem[index])
+    except:
+        logger.error('Sort failed for item %s' % type(item))
+        pass
+
+    return newitem