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Diffstat (limited to 'extras/waf_xattr.py')
| -rw-r--r-- | extras/waf_xattr.py | 150 |
1 files changed, 0 insertions, 150 deletions
diff --git a/extras/waf_xattr.py b/extras/waf_xattr.py deleted file mode 100644 index 351dd63..0000000 --- a/extras/waf_xattr.py +++ /dev/null @@ -1,150 +0,0 @@ -#! /usr/bin/env python -# encoding: utf-8 - -""" -Use extended attributes instead of database files - -1. Input files will be made writable -2. This is only for systems providing extended filesystem attributes -3. By default, hashes are calculated only if timestamp/size change (HASH_CACHE below) -4. The module enables "deep_inputs" on all tasks by propagating task signatures -5. This module also skips task signature comparisons for task code changes due to point 4. -6. This module is for Python3/Linux only, but it could be extended to Python2/other systems - using the xattr library -7. For projects in which tasks always declare output files, it should be possible to - store the rest of build context attributes on output files (imp_sigs, raw_deps and node_deps) - but this is not done here - -On a simple C++ project benchmark, the variations before and after adding waf_xattr.py were observed: -total build time: 20s -> 22s -no-op build time: 2.4s -> 1.8s -pickle file size: 2.9MB -> 2.6MB -""" - -import os -from waflib import Logs, Node, Task, Utils, Errors -from waflib.Task import SKIP_ME, RUN_ME, CANCEL_ME, ASK_LATER, SKIPPED, MISSING - -HASH_CACHE = True -SIG_VAR = 'user.waf.sig' -SEP = ','.encode() -TEMPLATE = '%b%d,%d'.encode() - -try: - PermissionError -except NameError: - PermissionError = IOError - -def getxattr(self): - return os.getxattr(self.abspath(), SIG_VAR) - -def setxattr(self, val): - os.setxattr(self.abspath(), SIG_VAR, val) - -def h_file(self): - try: - ret = getxattr(self) - except OSError: - if HASH_CACHE: - st = os.stat(self.abspath()) - mtime = st.st_mtime - size = st.st_size - else: - if len(ret) == 16: - # for build directory files - return ret - - if HASH_CACHE: - # check if timestamp and mtime match to avoid re-hashing - st = os.stat(self.abspath()) - mtime, size = ret[16:].split(SEP) - if int(1000 * st.st_mtime) == int(mtime) and st.st_size == int(size): - return ret[:16] - - ret = Utils.h_file(self.abspath()) - if HASH_CACHE: - val = TEMPLATE % (ret, int(1000 * st.st_mtime), int(st.st_size)) - try: - setxattr(self, val) - except PermissionError: - os.chmod(self.abspath(), st.st_mode | 128) - setxattr(self, val) - return ret - -def runnable_status(self): - bld = self.generator.bld - if bld.is_install < 0: - return SKIP_ME - - for t in self.run_after: - if not t.hasrun: - return ASK_LATER - elif t.hasrun < SKIPPED: - # a dependency has an error - return CANCEL_ME - - # first compute the signature - try: - new_sig = self.signature() - except Errors.TaskNotReady: - return ASK_LATER - - if not self.outputs: - # compare the signature to a signature computed previously - # this part is only for tasks with no output files - key = self.uid() - try: - prev_sig = bld.task_sigs[key] - except KeyError: - Logs.debug('task: task %r must run: it was never run before or the task code changed', self) - return RUN_ME - if new_sig != prev_sig: - Logs.debug('task: task %r must run: the task signature changed', self) - return RUN_ME - - # compare the signatures of the outputs to make a decision - for node in self.outputs: - try: - sig = node.h_file() - except EnvironmentError: - Logs.debug('task: task %r must run: an output node does not exist', self) - return RUN_ME - if sig != new_sig: - Logs.debug('task: task %r must run: an output node is stale', self) - return RUN_ME - - return (self.always_run and RUN_ME) or SKIP_ME - -def post_run(self): - bld = self.generator.bld - sig = self.signature() - for node in self.outputs: - if not node.exists(): - self.hasrun = MISSING - self.err_msg = '-> missing file: %r' % node.abspath() - raise Errors.WafError(self.err_msg) - os.setxattr(node.abspath(), 'user.waf.sig', sig) - if not self.outputs: - # only for task with no outputs - bld.task_sigs[self.uid()] = sig - if not self.keep_last_cmd: - try: - del self.last_cmd - except AttributeError: - pass - -try: - os.getxattr -except AttributeError: - pass -else: - h_file.__doc__ = Node.Node.h_file.__doc__ - - # keep file hashes as file attributes - Node.Node.h_file = h_file - - # enable "deep_inputs" on all tasks - Task.Task.runnable_status = runnable_status - Task.Task.post_run = post_run - Task.Task.sig_deep_inputs = Utils.nada - |