waf/waflib/extras/md5_tstamp.py

69 lines
2.1 KiB
Python

#! /usr/bin/env python
# encoding: utf-8
"""
This module assumes that only one build context is running at a given time, which
is not the case if you want to execute configuration tests in parallel.
Store some values on the buildcontext mapping file paths to
stat values and md5 values (timestamp + md5)
this way the md5 hashes are computed only when timestamp change (can be faster)
There is usually little or no gain from enabling this, but it can be used to enable
the second level cache with timestamps (WAFCACHE)
You may have to run distclean or to remove the build directory before enabling/disabling
this hashing scheme
"""
import os, stat
from waflib import Utils, Build, Context
STRONGEST = True
try:
Build.BuildContext.store_real
except AttributeError:
Context.DBFILE += '_md5tstamp'
Build.hashes_md5_tstamp = {}
Build.SAVED_ATTRS.append('hashes_md5_tstamp')
def store(self):
# save the hash cache as part of the default pickle file
self.hashes_md5_tstamp = Build.hashes_md5_tstamp
self.store_real()
Build.BuildContext.store_real = Build.BuildContext.store
Build.BuildContext.store = store
def restore(self):
# we need a module variable for h_file below
self.restore_real()
try:
Build.hashes_md5_tstamp = self.hashes_md5_tstamp or {}
except AttributeError:
Build.hashes_md5_tstamp = {}
Build.BuildContext.restore_real = Build.BuildContext.restore
Build.BuildContext.restore = restore
def h_file(filename):
st = os.stat(filename)
if stat.S_ISDIR(st[stat.ST_MODE]): raise IOError('not a file')
if filename in Build.hashes_md5_tstamp:
if Build.hashes_md5_tstamp[filename][0] == str(st.st_mtime):
return Build.hashes_md5_tstamp[filename][1]
if STRONGEST:
ret = Utils.h_file_no_md5(filename)
Build.hashes_md5_tstamp[filename] = (str(st.st_mtime), ret)
return ret
else:
m = Utils.md5()
m.update(str(st.st_mtime))
m.update(str(st.st_size))
m.update(filename)
Build.hashes_md5_tstamp[filename] = (str(st.st_mtime), m.digest())
return m.digest()
Utils.h_file_no_md5 = Utils.h_file
Utils.h_file = h_file