print "NOTE: Importing cPickle failed. Falling back to a very slow implementation."
class Cache:
-
+ """
+ BitBake Cache implementation
+ """
def __init__(self, cooker):
self.cachedir = bb.data.getVar("CACHE", cooker.configuration.data, True)
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]
self.depends_cache[fn] = {}
if fn != self.data_fn:
- bb.fatal("Parsing error data_fn %s and fn %s don't match" % (self.data_fn, 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
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, False
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 False, skipped
def cacheValid(self, fn):
+ """
+ Is the cache valid for fn?
+ Fast version, no timestamps checked.
+ """
# Is cache enabled?
if self.cachedir in [None, '']:
return False
return False
def cacheValidUpdate(self, fn):
+ """
+ Is the cache valid for fn?
+ Make thorough (slower) checks including timestamps.
+ """
# Is cache enabled?
if self.cachedir in [None, '']:
return False
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.note("Removing %s from cache" % fn)
if fn in self.depends_cache:
del self.depends_cache[fn]
def sync(self):
+ """
+ Save the cache
+ Called from the parser when complete (or exitting)
+ """
p = pickle.Pickler(file(self.cachefile, "wb" ), -1 )
p.dump(self.depends_cache)
return 0
def load_bbfile( self, bbfile , cooker):
- """Load and parse one .bb build file"""
+ """
+ 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
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)