1 files changed, 306 insertions, 0 deletions

diff --git a/bitbake/lib/bb/cache.py b/bitbake/lib/bb/cache.py
new file mode 100644
index 0000000000..921a9f7589
--- /dev/null
+++ b/bitbake/lib/bb/cache.py
@@ -0,0 +1,306 @@
+#!/usr/bin/env python
+# ex:ts=4:sw=4:sts=4:et
+# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
+"""
+BitBake 'Event' implementation
+
+Caching of bitbake variables before task execution
+
+# Copyright (C) 2006        Richard Purdie
+
+# 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 as published by the Free Software
+Foundation; either version 2 of the License, or (at your option) any later
+version.
+
+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 os, re
+import bb.data
+import bb.utils
+
+try:
+    import cPickle as pickle
+except ImportError:
+    import pickle
+    print "NOTE: Importing cPickle failed. Falling back to a very slow implementation."
+
+# __cache_version__ = "123"
+__cache_version__ = "124" # changes the __depends structure
+
+class Cache:
+    """
+    BitBake Cache implementation
+    """
+    def __init__(self, cooker):
+
+
+        self.cachedir = bb.data.getVar("CACHE", cooker.configuration.data, True)
+        self.clean = {}
+        self.depends_cache = {}
+        self.data = None
+        self.data_fn = None
+
+        if self.cachedir in [None, '']:
+            self.has_cache = False
+            if cooker.cb is not None:
+                print "NOTE: Not using a cache. Set CACHE = <directory> to enable."
+        else:
+            self.has_cache = True
+            self.cachefile = os.path.join(self.cachedir,"bb_cache.dat")
+            
+            if cooker.cb is not None:
+                print "NOTE: Using cache in '%s'" % self.cachedir
+            try:
+                os.stat( self.cachedir )
+            except OSError:
+                bb.mkdirhier( self.cachedir )
+
+        if self.has_cache and (self.mtime(self.cachefile)):
+            try:
+                p = pickle.Unpickler( file(self.cachefile,"rb"))
+                self.depends_cache, version_data = p.load()
+                if version_data['CACHE_VER'] != __cache_version__:
+                    raise ValueError, 'Cache Version Mismatch'
+                if version_data['BITBAKE_VER'] != bb.__version__:
+                    raise ValueError, 'Bitbake Version Mismatch'
+            except (ValueError, KeyError):
+                bb.note("Invalid cache found, rebuilding...")
+                self.depends_cache = {}
+
+        if self.depends_cache:
+            for fn in self.depends_cache.keys():
+                self.clean[fn] = ""
+                self.cacheValidUpdate(fn)
+
+    def getVar(self, var, fn, exp = 0):
+        """
+        Gets the value of a variable
+        (similar to getVar in the data class)
+        
+        There are two scenarios:
+          1. We have cached data - serve from depends_cache[fn]
+          2. We're learning what data to cache - serve from data 
+             backend but add a copy of the data to the cache.
+        """
+
+        if fn in self.clean:
+            return self.depends_cache[fn][var]
+
+        if not fn in self.depends_cache:
+            self.depends_cache[fn] = {}
+
+        if fn != self.data_fn:
+            # We're trying to access data in the cache which doesn't exist
+            # yet setData hasn't been called to setup the right access. Very bad.
+            bb.error("Parsing error data_fn %s and fn %s don't match" % (self.data_fn, fn))
+
+        result = bb.data.getVar(var, self.data, exp)
+        self.depends_cache[fn][var] = result
+        return result
+
+    def setData(self, fn, data):
+        """
+        Called to prime bb_cache ready to learn which variables to cache.
+        Will be followed by calls to self.getVar which aren't cached
+        but can be fulfilled from self.data.
+        """
+        self.data_fn = fn
+        self.data = data
+
+        # Make sure __depends makes the depends_cache
+        self.getVar("__depends", fn, True)
+        self.depends_cache[fn]["CACHETIMESTAMP"] = bb.parse.cached_mtime(fn)
+
+    def loadDataFull(self, fn, cooker):
+        """
+        Return a complete set of data for fn.
+        To do this, we need to parse the file.
+        """
+        bb_data, skipped = self.load_bbfile(fn, cooker)
+        return bb_data
+
+    def loadData(self, fn, cooker):
+        """
+        Load a subset of data for fn.
+        If the cached data is valid we do nothing,
+        To do this, we need to parse the file and set the system
+        to record the variables accessed.
+        Return the cache status and whether the file was skipped when parsed
+        """
+        if self.cacheValid(fn):
+            if "SKIPPED" in self.depends_cache[fn]:
+                return True, True
+            return True, False
+
+        bb_data, skipped = self.load_bbfile(fn, cooker)
+        self.setData(fn, bb_data)
+        return False, skipped
+
+    def cacheValid(self, fn):
+        """
+        Is the cache valid for fn?
+        Fast version, no timestamps checked.
+        """
+        # Is cache enabled?
+        if not self.has_cache:
+            return False
+        if fn in self.clean:
+            return True
+        return False
+
+    def cacheValidUpdate(self, fn):
+        """
+        Is the cache valid for fn?
+        Make thorough (slower) checks including timestamps.
+        """
+        # Is cache enabled?
+        if not self.has_cache:
+            return False
+
+        # Check file still exists
+        if self.mtime(fn) == 0:
+            bb.debug(2, "Cache: %s not longer exists" % fn)
+            self.remove(fn)
+            return False
+
+        # File isn't in depends_cache
+        if not fn in self.depends_cache:
+            bb.debug(2, "Cache: %s is not cached" % fn)
+            self.remove(fn)
+            return False
+
+        # Check the file's timestamp
+        if bb.parse.cached_mtime(fn) > self.getVar("CACHETIMESTAMP", fn, True):
+            bb.debug(2, "Cache: %s changed" % fn)
+            self.remove(fn)
+            return False
+
+        # Check dependencies are still valid
+        depends = self.getVar("__depends", fn, True)
+        for f,old_mtime in depends:
+            new_mtime = bb.parse.cached_mtime(f)
+            if (new_mtime > old_mtime):
+                bb.debug(2, "Cache: %s's dependency %s changed" % (fn, f))
+                self.remove(fn)
+                return False
+
+        bb.debug(2, "Depends Cache: %s is clean" % fn)
+        if not fn in self.clean:
+            self.clean[fn] = ""
+
+        return True
+
+    def skip(self, fn):
+        """
+        Mark a fn as skipped
+        Called from the parser
+        """
+        if not fn in self.depends_cache:
+            self.depends_cache[fn] = {}
+        self.depends_cache[fn]["SKIPPED"] = "1"
+
+    def remove(self, fn):
+        """
+        Remove a fn from the cache
+        Called from the parser in error cases
+        """
+        bb.debug(1, "Removing %s from cache" % fn)
+        if fn in self.depends_cache:
+            del self.depends_cache[fn]
+        if fn in self.clean:
+            del self.clean[fn]
+
+    def sync(self):
+        """
+        Save the cache
+        Called from the parser when complete (or exitting)
+        """
+
+        if not self.has_cache:
+            return
+
+        version_data = {}
+        version_data['CACHE_VER'] = __cache_version__
+        version_data['BITBAKE_VER'] = bb.__version__
+
+        p = pickle.Pickler(file(self.cachefile, "wb" ), -1 )
+        p.dump([self.depends_cache, version_data])
+
+    def mtime(self, cachefile):
+        try:
+            return os.stat(cachefile)[8]
+        except OSError:
+            return 0
+
+    def load_bbfile( self, bbfile , cooker):
+        """
+        Load and parse one .bb build file
+        Return the data and whether parsing resulted in the file being skipped
+        """
+
+        import bb
+        from bb import utils, data, parse, debug, event, fatal
+
+        topdir = data.getVar('TOPDIR', cooker.configuration.data)
+        if not topdir:
+            topdir = os.path.abspath(os.getcwd())
+            # set topdir to here
+            data.setVar('TOPDIR', topdir, cooker.configuration)
+        bbfile = os.path.abspath(bbfile)
+        bbfile_loc = os.path.abspath(os.path.dirname(bbfile))
+        # expand tmpdir to include this topdir
+        data.setVar('TMPDIR', data.getVar('TMPDIR', cooker.configuration.data, 1) or "", cooker.configuration.data)
+        # set topdir to location of .bb file
+        topdir = bbfile_loc
+        #data.setVar('TOPDIR', topdir, cfg)
+        # go there
+        oldpath = os.path.abspath(os.getcwd())
+        if self.mtime(topdir):
+            os.chdir(topdir)
+        bb_data = data.init_db(cooker.configuration.data)
+        try:
+            parse.handle(bbfile, bb_data) # read .bb data
+            os.chdir(oldpath)
+            return bb_data, False
+        except bb.parse.SkipPackage:
+            os.chdir(oldpath)
+            return bb_data, True
+        except:
+            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.SkipPackage exception
+
+    Files causing parsing errors are evicted from the cache.
+
+    """
+    return Cache(cooker)
+