removed the cache from the task level, it usually degrades performance and is better implemented on the compiler level

ChangeLog

@@ -1,7 +1,7 @@
 NEW IN WAF 1.8.0
 ----------------
 * Do not propagate external static libraries uselib vars #1320
-* 
+* Removed the Waf cache from the task level
 
 NEW IN WAF 1.7.11
 -----------------

docs/book/execution.txt

@@ -370,7 +370,6 @@ Options:
   -j JOBS, --jobs=JOBS  amount of parallel jobs (2)
   -k, --keep            keep running happily even if errors are found
   -v, --verbose         verbosity level -v -vv or -vvv [default: 0]
-  --nocache             ignore the WAFCACHE (if set)
   --zones=ZONES         debugging zones (task_gen, deps, tasks, etc)
 
   configure options:

waflib/Build.py

@@ -96,8 +96,6 @@ class BuildContext(Context.Context):
 		self.jobs = Options.options.jobs
 		self.targets = Options.options.targets
 		self.keep = Options.options.keep
-		self.cache_global = Options.cache_global
-		self.nocache = Options.options.nocache
 		self.progress_bar = Options.options.progress_bar
 
 		############ stuff below has not been reviewed

waflib/Options.py

@@ -36,8 +36,6 @@ List of commands to execute extracted from the command-line. This list is consum
 """
 
 lockfile = os.environ.get('WAFLOCK', '.lock-waf_%s_build' % sys.platform)
-try: cache_global = os.path.abspath(os.environ['WAFCACHE'])
-except KeyError: cache_global = ''
 platform = Utils.unversioned_sys_platform()
 
 
@@ -56,7 +54,6 @@ class opt_parser(optparse.OptionParser):
 		p('-j', '--jobs',     dest='jobs',    default=jobs, type='int', help='amount of parallel jobs (%r)' % jobs)
 		p('-k', '--keep',     dest='keep',    default=0,     action='count', help='keep running happily even if errors are found')
 		p('-v', '--verbose',  dest='verbose', default=0,     action='count', help='verbosity level -v -vv or -vvv [default: 0]')
-		p('--nocache',        dest='nocache', default=False, action='store_true', help='ignore the WAFCACHE (if set)')
 		p('--zones',          dest='zones',   default='',    action='store', help='debugging zones (task_gen, deps, tasks, etc)')
 
 		gr = optparse.OptionGroup(self, 'configure options')

waflib/Task.py

@@ -63,40 +63,6 @@ def f(tsk):
 	return tsk.exec_command(lst, cwd=wd, env=env.env or None)
 '''
 
-def cache_outputs(cls):
-	"""
-	Task class decorator applied to all task classes by default unless they define the attribute 'nocache'::
-
-		from waflib import Task
-		class foo(Task.Task):
-			nocache = True
-
-	If bld.cache_global is defined and if the task instances produces output nodes,
-	the files will be copied into a folder in the cache directory
-
-	The files may also be retrieved from that folder, if it exists
-	"""
-	m1 = cls.run
-	def run(self):
-		bld = self.generator.bld
-		if bld.cache_global and not bld.nocache:
-			if self.can_retrieve_cache():
-				return 0
-		return m1(self)
-	cls.run = run
-
-	m2 = cls.post_run
-	def post_run(self):
-		bld = self.generator.bld
-		ret = m2(self)
-		if bld.cache_global and not bld.nocache:
-			self.put_files_cache()
-		return ret
-	cls.post_run = post_run
-
-	return cls
-
-
 classes = {}
 "class tasks created by user scripts or Waf tools are kept in this dict name -> class object"
 
@@ -128,9 +94,6 @@ class store_task_type(type):
 				# getattr(cls, 'hcode') would look in the upper classes
 				cls.hcode = Utils.h_fun(cls.run)
 
-			if not getattr(cls, 'nocache', None):
-				cls = cache_outputs(cls)
-
 			# be creative
 			getattr(cls, 'register', classes)[name] = cls
 
@@ -811,107 +774,6 @@ class Task(TaskBase):
 					#print "task is not ready..."
 					raise Errors.TaskNotReady('not ready')
 
-	def can_retrieve_cache(self):
-		"""
-		Used by :py:meth:`waflib.Task.cache_outputs`
-
-		Retrieve build nodes from the cache
-		update the file timestamps to help cleaning the least used entries from the cache
-		additionally, set an attribute 'cached' to avoid re-creating the same cache files
-
-		Suppose there are files in `cache/dir1/file1` and `cache/dir2/file2`:
-
-		#. read the timestamp of dir1
-		#. try to copy the files
-		#. look at the timestamp again, if it has changed, the data may have been corrupt (cache update by another process)
-		#. should an exception occur, ignore the data
-		"""
-
-		if not getattr(self, 'outputs', None):
-			return None
-
-		sig = self.signature()
-		ssig = Utils.to_hex(self.uid()) + Utils.to_hex(sig)
-
-		# first try to access the cache folder for the task
-		dname = os.path.join(self.generator.bld.cache_global, ssig)
-		try:
-			t1 = os.stat(dname).st_mtime
-		except OSError:
-			return None
-
-		for node in self.outputs:
-			orig = os.path.join(dname, node.name)
-			try:
-				shutil.copy2(orig, node.abspath())
-				# mark the cache file as used recently (modified)
-				os.utime(orig, None)
-			except (OSError, IOError):
-				Logs.debug('task: failed retrieving file')
-				return None
-
-		# is it the same folder?
-		try:
-			t2 = os.stat(dname).st_mtime
-		except OSError:
-			return None
-
-		if t1 != t2:
-			return None
-
-		for node in self.outputs:
-			node.sig = sig
-			if self.generator.bld.progress_bar < 1:
-				self.generator.bld.to_log('restoring from cache %r\n' % node.abspath())
-
-		self.cached = True
-		return True
-
-	def put_files_cache(self):
-		"""
-		Used by :py:func:`waflib.Task.cache_outputs` to store the build files in the cache
-		"""
-
-		# file caching, if possible
-		# try to avoid data corruption as much as possible
-		if getattr(self, 'cached', None):
-			return None
-		if not getattr(self, 'outputs', None):
-			return None
-
-		sig = self.signature()
-		ssig = Utils.to_hex(self.uid()) + Utils.to_hex(sig)
-		dname = os.path.join(self.generator.bld.cache_global, ssig)
-		tmpdir = tempfile.mkdtemp(prefix=self.generator.bld.cache_global + os.sep + 'waf')
-
-		try:
-			shutil.rmtree(dname)
-		except Exception:
-			pass
-
-		try:
-			for node in self.outputs:
-				dest = os.path.join(tmpdir, node.name)
-				shutil.copy2(node.abspath(), dest)
-		except (OSError, IOError):
-			try:
-				shutil.rmtree(tmpdir)
-			except Exception:
-				pass
-		else:
-			try:
-				os.rename(tmpdir, dname)
-			except OSError:
-				try:
-					shutil.rmtree(tmpdir)
-				except Exception:
-					pass
-			else:
-				try:
-					os.chmod(dname, Utils.O755)
-				except Exception:
-					pass
-
 def is_before(t1, t2):
 	"""
 	Return a non-zero value if task t1 is to be executed before task t2::

waflib/Tools/c_config.py

@@ -1190,8 +1190,6 @@ def multicheck(self, *k, **kw):
 	class par(object):
 		def __init__(self):
 			self.keep = False
-			self.cache_global = Options.cache_global
-			self.nocache = Options.options.nocache
 			self.returned_tasks = []
 			self.task_sigs = {}
 		def total(self):

waflib/Tools/fc.py

@@ -160,10 +160,6 @@ class fcshlib(fcprogram):
 class fcprogram_test(fcprogram):
 	"""Custom link task to obtain the compiler outputs for fortran configuration tests"""
 
-	def can_retrieve_cache(self):
-		"""This task is always executed"""
-		return False
-
 	def runnable_status(self):
 		"""This task is always executed"""
 		ret = super(fcprogram_test, self).runnable_status()

waflib/Tools/javaw.py

@@ -236,11 +236,6 @@ class javac(Task.Task):
 	"""
 	color   = 'BLUE'
 
-	nocache = True
-	"""
-	The .class files cannot be put into a cache at the moment
-	"""
-
 	vars = ['CLASSPATH', 'JAVACFLAGS', 'JAVAC', 'OUTDIR']
 	"""
 	The javac task will be executed again if the variables CLASSPATH, JAVACFLAGS, JAVAC or OUTDIR change.

waflib/extras/batched_cc.py

@@ -141,21 +141,8 @@ for x in ['c', 'cxx']:
 		#self.executed=1
 		pass
 
-	def can_retrieve_cache(self):
-		if self.old_can_retrieve_cache():
-			for m in self.generator.allmasters:
-				try:
-					m.slaves.remove(self)
-				except ValueError:
-					pass #this task wasn't included in that master
-			return 1
-		else:
-			return None
-
 	setattr(t, 'oldrun', t.__dict__['run'])
 	setattr(t, 'run', run)
 	setattr(t, 'old_post_run', t.post_run)
 	setattr(t, 'post_run', post_run)
-	setattr(t, 'old_can_retrieve_cache', t.can_retrieve_cache)
-	setattr(t, 'can_retrieve_cache', can_retrieve_cache)