tinfoil: rewrite as a wrapper around the UI

Rewrite tinfoil as a wrapper around the UI, instead of the earlier
approach of starting up just enough of cooker to do what we want. This
has several advantages:

* It now works when bitbake is memory-resident instead of failing with
  "ERROR: Only one copy of bitbake should be run against a build
  directory".

* We can now connect an actual UI, thus you get things like the recipe
  parsing / cache loading progress bar and parse error handling for free

* We can now handle events generated by the server if we wish to do so

* We can potentially extend this to do more stuff, e.g. actually running
  build operations - this needs to be made more practical before we can
  use it though (since you effectively have to become the UI yourself
  for this at the moment.)

The downside is that tinfoil no longer has direct access to cooker, the
global datastore, or the cache. To mitigate this I have extended
data_smart to provide remote access capability for the datastore, and
created "fake" cooker and cooker.recipecache / cooker.collection adapter
objects in order to avoid breaking too many tinfoil-using scripts that
might be out there (we've never officially documented tinfoil or
BitBake's internal code, but we can still make accommodations where
practical). I've at least gone far enough to support all of the
utilities that use tinfoil in OE-Core with some changes, but I know
there are scripts such as Chris Larson's "bb" out there that do make
other calls into BitBake code that I'm not currently providing access to
through the adapters.

Part of the fix for [YOCTO #5470].

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 74 insertions, 0 deletions

diff --git a/lib/bb/remotedata.py b/lib/bb/remotedata.py
new file mode 100644
index 000000000..932ee430e
--- /dev/null
+++ b/lib/bb/remotedata.py
@@ -0,0 +1,74 @@
+"""
+BitBake 'remotedata' module
+
+Provides support for using a datastore from the bitbake client
+"""
+
+# Copyright (C) 2016  Intel Corporation
+#
+# 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 bb.data
+
+class RemoteDatastores:
+    """Used on the server side to manage references to server-side datastores"""
+    def __init__(self, cooker):
+        self.cooker = cooker
+        self.datastores = {}
+        self.locked = []
+        self.nextindex = 1
+
+    def __len__(self):
+        return len(self.datastores)
+
+    def __getitem__(self, key):
+        if key is None:
+            return self.cooker.data
+        else:
+            return self.datastores[key]
+
+    def items(self):
+        return self.datastores.items()
+
+    def store(self, d, locked=False):
+        """
+        Put a datastore into the collection. If locked=True then the datastore
+        is understood to be managed externally and cannot be released by calling
+        release().
+        """
+        idx = self.nextindex
+        self.datastores[idx] = d
+        if locked:
+            self.locked.append(idx)
+        self.nextindex += 1
+        return idx
+
+    def check_store(self, d, locked=False):
+        """
+        Put a datastore into the collection if it's not already in there;
+        in either case return the index
+        """
+        for key, val in self.datastores.items():
+            if val is d:
+                idx = key
+                break
+        else:
+            idx = self.store(d, locked)
+        return idx
+
+    def release(self, idx):
+        """Discard a datastore in the collection"""
+        if idx in self.locked:
+            raise Exception('Tried to release locked datastore %d' % idx)
+        del self.datastores[idx]