Squashed 'waflib/' content from commit 391d285

git-subtree-dir: waflib
git-subtree-split: 391d2853c6c97efc90e466f187675e8155c866d6

1 files changed, 518 insertions, 0 deletions

diff --git a/extras/fast_partial.py b/extras/fast_partial.py
new file mode 100644
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+++ b/extras/fast_partial.py
@@ -0,0 +1,518 @@
+#! /usr/bin/env python
+# encoding: utf-8
+# Thomas Nagy, 2017-2018 (ita)
+
+"""
+A system for fast partial rebuilds
+
+Creating a large amount of task objects up front can take some time.
+By making a few assumptions, it is possible to avoid posting creating
+task objects for targets that are already up-to-date.
+
+On a silly benchmark the gain observed for 1M tasks can be 5m->10s
+for a single file change.
+
+Usage::
+
+	def options(opt):
+		opt.load('fast_partial')
+
+Assuptions:
+* Mostly for C/C++/Fortran targets with link tasks (object-only targets are not handled)
+* For full project builds: no --targets and no pruning from subfolders
+* The installation phase is ignored
+* `use=` dependencies are specified up front even across build groups
+* Task generator source files are not obtained from globs
+
+Implementation details:
+* The first layer obtains file timestamps to recalculate file hashes only
+  when necessary (similar to md5_tstamp); the timestamps are then stored
+  in a dedicated pickle file
+* A second layer associates each task generator to a file set to help
+  detecting changes. Task generators are to create their tasks only when
+  the related files have been modified. A specific db file is created
+  to store such data (5m -> 1m10)
+* A third layer binds build context proxies onto task generators, replacing
+  the default context. While loading data for the full build uses more memory
+  (4GB -> 9GB), partial builds are then much faster (1m10 -> 13s)
+* A fourth layer enables a 2-level cache on file signatures to
+  reduce the size of the main pickle file (13s -> 10s)
+"""
+
+import os
+from waflib import Build, Context, Errors, Logs, Task, TaskGen, Utils
+from waflib.TaskGen import feature, after_method, taskgen_method
+import waflib.Node
+
+DONE = 0
+DIRTY = 1
+NEEDED = 2
+
+SKIPPABLE = ['cshlib', 'cxxshlib', 'cstlib', 'cxxstlib', 'cprogram', 'cxxprogram']
+
+TSTAMP_DB = '.wafpickle_tstamp_db_file'
+
+SAVED_ATTRS = 'root node_sigs task_sigs imp_sigs raw_deps node_deps'.split()
+
+class bld_proxy(object):
+	def __init__(self, bld):
+		object.__setattr__(self, 'bld', bld)
+
+		object.__setattr__(self, 'node_class', type('Nod3', (waflib.Node.Node,), {}))
+		self.node_class.__module__ = 'waflib.Node'
+		self.node_class.ctx = self
+
+		object.__setattr__(self, 'root', self.node_class('', None))
+		for x in SAVED_ATTRS:
+			if x != 'root':
+				object.__setattr__(self, x, {})
+
+		self.fix_nodes()
+
+	def __setattr__(self, name, value):
+		bld = object.__getattribute__(self, 'bld')
+		setattr(bld, name, value)
+
+	def __delattr__(self, name):
+		bld = object.__getattribute__(self, 'bld')
+		delattr(bld, name)
+
+	def __getattribute__(self, name):
+		try:
+			return object.__getattribute__(self, name)
+		except AttributeError:
+			bld = object.__getattribute__(self, 'bld')
+			return getattr(bld, name)
+
+	def __call__(self, *k, **kw):
+		return self.bld(*k, **kw)
+
+	def fix_nodes(self):
+		for x in ('srcnode', 'path', 'bldnode'):
+			node = self.root.find_dir(getattr(self.bld, x).abspath())
+			object.__setattr__(self, x, node)
+
+	def set_key(self, store_key):
+		object.__setattr__(self, 'store_key', store_key)
+
+	def fix_tg_path(self, *tgs):
+		# changing Node objects on task generators is possible
+		# yet, all Node objects must belong to the same parent
+		for tg in tgs:
+			tg.path = self.root.make_node(tg.path.abspath())
+
+	def restore(self):
+		dbfn = os.path.join(self.variant_dir, Context.DBFILE + self.store_key)
+		Logs.debug('rev_use: reading %s', dbfn)
+		try:
+			data = Utils.readf(dbfn, 'rb')
+		except (EnvironmentError, EOFError):
+			# handle missing file/empty file
+			Logs.debug('rev_use: Could not load the build cache %s (missing)', dbfn)
+		else:
+			try:
+				waflib.Node.pickle_lock.acquire()
+				waflib.Node.Nod3 = self.node_class
+				try:
+					data = Build.cPickle.loads(data)
+				except Exception as e:
+					Logs.debug('rev_use: Could not pickle the build cache %s: %r', dbfn, e)
+				else:
+					for x in SAVED_ATTRS:
+						object.__setattr__(self, x, data.get(x, {}))
+			finally:
+				waflib.Node.pickle_lock.release()
+		self.fix_nodes()
+
+	def store(self):
+		data = {}
+		for x in Build.SAVED_ATTRS:
+			data[x] = getattr(self, x)
+		db = os.path.join(self.variant_dir, Context.DBFILE + self.store_key)
+
+		try:
+			waflib.Node.pickle_lock.acquire()
+			waflib.Node.Nod3 = self.node_class
+			x = Build.cPickle.dumps(data, Build.PROTOCOL)
+		finally:
+			waflib.Node.pickle_lock.release()
+
+		Logs.debug('rev_use: storing %s', db)
+		Utils.writef(db + '.tmp', x, m='wb')
+		try:
+			st = os.stat(db)
+			os.remove(db)
+			if not Utils.is_win32:
+				os.chown(db + '.tmp', st.st_uid, st.st_gid)
+		except (AttributeError, OSError):
+			pass
+		os.rename(db + '.tmp', db)
+
+class bld(Build.BuildContext):
+	def __init__(self, **kw):
+		super(bld, self).__init__(**kw)
+		self.hashes_md5_tstamp = {}
+
+	def __call__(self, *k, **kw):
+		# this is one way of doing it, one could use a task generator method too
+		bld = kw['bld'] = bld_proxy(self)
+		ret = TaskGen.task_gen(*k, **kw)
+		self.task_gen_cache_names = {}
+		self.add_to_group(ret, group=kw.get('group'))
+		ret.bld = bld
+		bld.set_key(ret.path.abspath().replace(os.sep, '') + str(ret.idx))
+		return ret
+
+	def is_dirty(self):
+		return True
+
+	def store_tstamps(self):
+		# Called after a build is finished
+		# For each task generator, record all files involved in task objects
+		# optimization: done only if there was something built
+		do_store = False
+		try:
+			f_deps = self.f_deps
+		except AttributeError:
+			f_deps = self.f_deps = {}
+			self.f_tstamps = {}
+
+		allfiles = set()
+		for g in self.groups:
+			for tg in g:
+				try:
+					staleness = tg.staleness
+				except AttributeError:
+					staleness = DIRTY
+
+				if staleness != DIRTY:
+					# DONE case: there was nothing built
+					# NEEDED case: the tg was brought in because of 'use' propagation
+					# but nothing really changed for them, there may be incomplete
+					# tasks (object files) and in this case it is best to let the next build
+					# figure out if an input/output file changed
+					continue
+
+				do_cache = False
+				for tsk in tg.tasks:
+					if tsk.hasrun == Task.SUCCESS:
+						do_cache = True
+						pass
+					elif tsk.hasrun == Task.SKIPPED:
+						pass
+					else:
+						# one failed task, clear the cache for this tg
+						try:
+							del f_deps[(tg.path.abspath(), tg.idx)]
+						except KeyError:
+							pass
+						else:
+							# just store the new state because there is a change
+							do_store = True
+
+						# skip the rest because there is no valid cache possible
+						break
+				else:
+					if not do_cache:
+						# all skipped, but is there anything in cache?
+						try:
+							f_deps[(tg.path.abspath(), tg.idx)]
+						except KeyError:
+							# probably cleared because a wscript file changed
+							# store it
+							do_cache = True
+
+					if do_cache:
+
+						# there was a rebuild, store the data structure too
+						tg.bld.store()
+
+						# all tasks skipped but no cache
+						# or a successful task build
+						do_store = True
+						st = set()
+						for tsk in tg.tasks:
+							st.update(tsk.inputs)
+							st.update(self.node_deps.get(tsk.uid(), []))
+
+						# TODO do last/when loading the tgs?
+						lst = []
+						for k in ('wscript', 'wscript_build'):
+							n = tg.path.find_node(k)
+							if n:
+								n.get_bld_sig()
+								lst.append(n.abspath())
+
+						lst.extend(sorted(x.abspath() for x in st))
+						allfiles.update(lst)
+						f_deps[(tg.path.abspath(), tg.idx)] = lst
+
+		for x in allfiles:
+			# f_tstamps has everything, while md5_tstamp can be relatively empty on partial builds
+			self.f_tstamps[x] = self.hashes_md5_tstamp[x][0]
+
+		if do_store:
+			dbfn = os.path.join(self.variant_dir, TSTAMP_DB)
+			Logs.debug('rev_use: storing %s', dbfn)
+			dbfn_tmp = dbfn + '.tmp'
+			x = Build.cPickle.dumps([self.f_tstamps, f_deps], Build.PROTOCOL)
+			Utils.writef(dbfn_tmp, x, m='wb')
+			os.rename(dbfn_tmp, dbfn)
+			Logs.debug('rev_use: stored %s', dbfn)
+
+	def store(self):
+		self.store_tstamps()
+		if self.producer.dirty:
+			Build.BuildContext.store(self)
+
+	def compute_needed_tgs(self):
+		# assume the 'use' keys are not modified during the build phase
+
+		dbfn = os.path.join(self.variant_dir, TSTAMP_DB)
+		Logs.debug('rev_use: Loading %s', dbfn)
+		try:
+			data = Utils.readf(dbfn, 'rb')
+		except (EnvironmentError, EOFError):
+			Logs.debug('rev_use: Could not load the build cache %s (missing)', dbfn)
+			self.f_deps = {}
+			self.f_tstamps = {}
+		else:
+			try:
+				self.f_tstamps, self.f_deps = Build.cPickle.loads(data)
+			except Exception as e:
+				Logs.debug('rev_use: Could not pickle the build cache %s: %r', dbfn, e)
+				self.f_deps = {}
+				self.f_tstamps = {}
+			else:
+				Logs.debug('rev_use: Loaded %s', dbfn)
+
+
+		# 1. obtain task generators that contain rebuilds
+		# 2. obtain the 'use' graph and its dual
+		stales = set()
+		reverse_use_map = Utils.defaultdict(list)
+		use_map = Utils.defaultdict(list)
+
+		for g in self.groups:
+			for tg in g:
+				if tg.is_stale():
+					stales.add(tg)
+
+				try:
+					lst = tg.use = Utils.to_list(tg.use)
+				except AttributeError:
+					pass
+				else:
+					for x in lst:
+						try:
+							xtg = self.get_tgen_by_name(x)
+						except Errors.WafError:
+							pass
+						else:
+							use_map[tg].append(xtg)
+							reverse_use_map[xtg].append(tg)
+
+		Logs.debug('rev_use: found %r stale tgs', len(stales))
+
+		# 3. dfs to post downstream tg as stale
+		visited = set()
+		def mark_down(tg):
+			if tg in visited:
+				return
+			visited.add(tg)
+			Logs.debug('rev_use: marking down %r as stale', tg.name)
+			tg.staleness = DIRTY
+			for x in reverse_use_map[tg]:
+				mark_down(x)
+		for tg in stales:
+			mark_down(tg)
+
+		# 4. dfs to find ancestors tg to mark as needed
+		self.needed_tgs = needed_tgs = set()
+		def mark_needed(tg):
+			if tg in needed_tgs:
+				return
+			needed_tgs.add(tg)
+			if tg.staleness == DONE:
+				Logs.debug('rev_use: marking up %r as needed', tg.name)
+				tg.staleness = NEEDED
+			for x in use_map[tg]:
+				mark_needed(x)
+		for xx in visited:
+			mark_needed(xx)
+
+		# so we have the whole tg trees to post in the set "needed"
+		# load their build trees
+		for tg in needed_tgs:
+			tg.bld.restore()
+			tg.bld.fix_tg_path(tg)
+
+		# the stale ones should be fully build, while the needed ones
+		# may skip a few tasks, see create_compiled_task and apply_link_after below
+		Logs.debug('rev_use: amount of needed task gens: %r', len(needed_tgs))
+
+	def post_group(self):
+		# assumption: we can ignore the folder/subfolders cuts
+		def tgpost(tg):
+			try:
+				f = tg.post
+			except AttributeError:
+				pass
+			else:
+				f()
+
+		if not self.targets or self.targets == '*':
+			for tg in self.groups[self.current_group]:
+				# this can cut quite a lot of tg objects
+				if tg in self.needed_tgs:
+					tgpost(tg)
+		else:
+			# default implementation
+			return Build.BuildContext.post_group()
+
+	def get_build_iterator(self):
+		if not self.targets or self.targets == '*':
+			self.compute_needed_tgs()
+		return Build.BuildContext.get_build_iterator(self)
+
+@taskgen_method
+def is_stale(self):
+	# assume no globs
+	self.staleness = DIRTY
+
+	# 1. the case of always stale targets
+	if getattr(self, 'always_stale', False):
+		return True
+
+	# 2. check if the db file exists
+	db = os.path.join(self.bld.variant_dir, Context.DBFILE)
+	try:
+		dbstat = os.stat(db).st_mtime
+	except OSError:
+		Logs.debug('rev_use: must post %r because this is a clean build')
+		return True
+
+	# 3. check if the configuration changed
+	if os.stat(self.bld.bldnode.find_node('c4che/build.config.py').abspath()).st_mtime > dbstat:
+		Logs.debug('rev_use: must post %r because the configuration has changed', self.name)
+		return True
+
+	# 3.a any tstamp data?
+	try:
+		f_deps = self.bld.f_deps
+	except AttributeError:
+		Logs.debug('rev_use: must post %r because there is no f_deps', self.name)
+		return True
+
+	# 4. check if this is the first build (no cache)
+	try:
+		lst = f_deps[(self.path.abspath(), self.idx)]
+	except KeyError:
+		Logs.debug('rev_use: must post %r because there it has no cached data', self.name)
+		return True
+
+	try:
+		cache = self.bld.cache_tstamp_rev_use
+	except AttributeError:
+		cache = self.bld.cache_tstamp_rev_use = {}
+
+	# 5. check the timestamp of each dependency files listed is unchanged
+	f_tstamps = self.bld.f_tstamps
+	for x in lst:
+		try:
+			old_ts = f_tstamps[x]
+		except KeyError:
+			Logs.debug('rev_use: must post %r because %r is not in cache', self.name, x)
+			return True
+
+		try:
+			try:
+				ts = cache[x]
+			except KeyError:
+				ts = cache[x] = os.stat(x).st_mtime
+		except OSError:
+			del f_deps[(self.path.abspath(), self.idx)]
+			Logs.debug('rev_use: must post %r because %r does not exist anymore', self.name, x)
+			return True
+		else:
+			if ts != old_ts:
+				Logs.debug('rev_use: must post %r because the timestamp on %r changed %r %r', self.name, x, old_ts, ts)
+				return True
+
+	self.staleness = DONE
+	return False
+
+@taskgen_method
+def create_compiled_task(self, name, node):
+	# skip the creation of object files
+	# assumption: object-only targets are not skippable
+	if self.staleness == NEEDED:
+		# only libraries/programs can skip object files
+		for x in SKIPPABLE:
+			if x in self.features:
+				return None
+
+	out = '%s.%d.o' % (node.name, self.idx)
+	task = self.create_task(name, node, node.parent.find_or_declare(out))
+	try:
+		self.compiled_tasks.append(task)
+	except AttributeError:
+		self.compiled_tasks = [task]
+	return task
+
+@feature(*SKIPPABLE)
+@after_method('apply_link')
+def apply_link_after(self):
+	# cprogram/cxxprogram might be unnecessary
+	if self.staleness != NEEDED:
+		return
+	for tsk in self.tasks:
+		tsk.hasrun = Task.SKIPPED
+
+def path_from(self, node):
+	# handle nodes of distinct types
+	if node.ctx is not self.ctx:
+		node = self.ctx.root.make_node(node.abspath())
+	return self.default_path_from(node)
+waflib.Node.Node.default_path_from = waflib.Node.Node.path_from
+waflib.Node.Node.path_from = path_from
+
+def h_file(self):
+	# similar to md5_tstamp.py, but with 2-layer cache
+	# global_cache for the build context common for all task generators
+	# local_cache for the build context proxy (one by task generator)
+	#
+	# the global cache is not persistent
+	# the local cache is persistent and meant for partial builds
+	#
+	# assume all calls are made from a single thread
+	#
+	filename = self.abspath()
+	st = os.stat(filename)
+
+	global_cache = self.ctx.bld.hashes_md5_tstamp
+	local_cache = self.ctx.hashes_md5_tstamp
+
+	if filename in global_cache:
+		# value already calculated in this build
+		cval = global_cache[filename]
+
+		# the value in global cache is assumed to be calculated once
+		# reverifying it could cause task generators
+		# to get distinct tstamp values, thus missing rebuilds
+		local_cache[filename] = cval
+		return cval[1]
+
+	if filename in local_cache:
+		cval = local_cache[filename]
+		if cval[0] == st.st_mtime:
+			# correct value from a previous build
+			# put it in the global cache
+			global_cache[filename] = cval
+			return cval[1]
+
+	ret = Utils.h_file(filename)
+	local_cache[filename] = global_cache[filename] = (st.st_mtime, ret)
+	return ret
+waflib.Node.Node.h_file = h_file
+