1 files changed, 67 insertions, 0 deletions
diff --git a/third_party/waf/waflib/extras/md5_tstamp.py b/third_party/waf/waflib/extras/md5_tstamp.py
new file mode 100644
index 00000000000..63b71d8d27a
--- /dev/null
+++ b/third_party/waf/waflib/extras/md5_tstamp.py
@@ -0,0 +1,67 @@
+#! /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