Squashed 'waflib/' changes from 6e726eb1..5ea8f99f

5ea8f99f Improve test output spacing
0e23b29f Raise exception when test suite fails to ensure non-zero exit status
d6de073b Show run time of unit tests
5b655541 Add short configure option for ultra-strict flags
4687ba6d Use gtest-like test output
258903d9 Fix failure count in test group summaries
da07e738 Fix verbose tests with Python 3

git-subtree-dir: waflib
git-subtree-split: 5ea8f99f6e1246079c1fe6bb590c38a53aadd40d

1 files changed, 39 insertions, 0 deletions

diff --git a/Tools/md5_tstamp.py b/Tools/md5_tstamp.py
new file mode 100644
index 00000000..6428e460
--- /dev/null
+++ b/Tools/md5_tstamp.py
@@ -0,0 +1,39 @@
+#! /usr/bin/env python
+# encoding: utf-8
+
+"""
+Re-calculate md5 hashes of files only when the file times or the file
+size have changed.
+
+The hashes can also reflect either the file contents (STRONGEST=True) or the
+file time and file size.
+
+The performance benefits of this module are usually insignificant.
+"""
+
+import os, stat
+from waflib import Utils, Build, Node
+
+STRONGEST = True
+
+Build.SAVED_ATTRS.append('hashes_md5_tstamp')
+def h_file(self):
+	filename = self.abspath()
+	st = os.stat(filename)
+
+	cache = self.ctx.hashes_md5_tstamp
+	if filename in cache and cache[filename][0] == st.st_mtime:
+		return cache[filename][1]
+
+	if STRONGEST:
+		ret = Utils.h_file(filename)
+	else:
+		if stat.S_ISDIR(st[stat.ST_MODE]):
+			raise IOError('Not a file')
+		ret = Utils.md5(str((st.st_mtime, st.st_size)).encode()).digest()
+
+	cache[filename] = (st.st_mtime, ret)
+	return ret
+h_file.__doc__ = Node.Node.h_file.__doc__
+Node.Node.h_file = h_file
+