Improve bincache accuracy: use md5 instead of mtime to verify that the binary files correspond

to the binary files being packaged.
mtime works well for binary files being compiled each time, but it is prone to be broken for
other patterns of usages. For instance, switching between different versions of a third-party
library (eg: wxPython) was totally broken without this fix, as only the newer binary file was
being packaged, not the current one.


git-svn-id: http://svn.pyinstaller.org/trunk@314 8dd32b29-ccff-0310-8a9a-9233e24343b1

Build.py

@@ -16,7 +16,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
-import sys, os, shutil, mf, archive, iu, carchive, pprint, time, py_compile, bindepend, tempfile
+import sys, os, shutil, mf, archive, iu, carchive, pprint, time, py_compile, bindepend, tempfile, md5
 
 STRINGTYPE = type('')
 TUPLETYPE = type((None,))
@@ -293,6 +293,11 @@ class PYZ(Target):
         outf.close()
         return 1
 
+def cacheDigest(fnm):
+    data = open(fnm, "rb").read()
+    digest = md5.new(data).digest()
+    return digest
+
 def checkCache(fnm, strip, upx):
     if not strip and not upx:
         return fnm
@@ -304,13 +309,23 @@ def checkCache(fnm, strip, upx):
         upx = 1
     else:
         upx = 0
+
+    # Load cache index
     cachedir = os.path.join(HOMEPATH, 'bincache%d%d' %  (strip, upx))
     if not os.path.exists(cachedir):
         os.makedirs(cachedir)
-    basenm = os.path.basename(fnm)
-    cachedfile = os.path.join(cachedir, basenm )
-    if os.path.exists(cachedfile):
-        if mtime(fnm) > mtime(cachedfile):
+    cacheindexfn = os.path.join(cachedir, "index.dat")
+    if os.path.exists(cacheindexfn):
+        cache_index = eval(open(cacheindexfn, "r").read())
+    else:
+        cache_index = {}
+
+    # Verify if the file we're looking for is present in the cache.
+    basenm = os.path.normcase(os.path.basename(fnm))
+    digest = cacheDigest(fnm)
+    cachedfile = os.path.join(cachedir, basenm)
+    if cache_index.has_key(basenm):
+        if digest != cache_index[basenm]:
             os.remove(cachedfile)
         else:
             return cachedfile
@@ -323,6 +338,13 @@ def checkCache(fnm, strip, upx):
     shutil.copy2(fnm, cachedfile)
     os.chmod(cachedfile, 0755)
     os.system(cmd)
+
+    # update cache index
+    cache_index[basenm] = digest
+    outf = open(cacheindexfn, 'w')
+    pprint.pprint(cache_index, outf)
+    outf.close()
+
     return cachedfile
 
 UNCOMPRESSED, COMPRESSED = range(2)