From de1ec4be8b0c7bc8c36e88a460e64b3be38cff35 Mon Sep 17 00:00:00 2001
From: Peter Scheibel <scheibel1@llnl.gov>
Date: Mon, 6 Jun 2016 12:26:13 -0700
Subject: [PATCH] change source archive caching to omit digest from name and
 instead calculate and compare the checksum. This achieves the original goal
 of discarding stale cache files without preserving multiple files for the
 same version.

---
 lib/spack/spack/fetch_strategy.py | 23 +++++++++++++++++++++--
 lib/spack/spack/mirror.py         |  8 +-------
 lib/spack/spack/package.py        |  9 ---------
 3 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/lib/spack/spack/fetch_strategy.py b/lib/spack/spack/fetch_strategy.py
index 4bbf7bb34c..fde2a8805e 100644
--- a/lib/spack/spack/fetch_strategy.py
+++ b/lib/spack/spack/fetch_strategy.py
@@ -343,7 +343,7 @@ def reset(self):
 
     def __repr__(self):
         url = self.url if self.url else "no url"
-        return "URLFetchStrategy<%s>" % url
+        return "%s<%s>" % (self.__class__.__name__, url)
 
     def __str__(self):
         if self.url:
@@ -352,6 +352,25 @@ def __str__(self):
             return "[no url]"
 
 
+class URLMirrorFetchStrategy(URLFetchStrategy):
+    """The resource associated with a URL at a mirror may be out of date.
+    """
+    def __init__(self, *args, **kwargs):
+        super(URLMirrorFetchStrategy, self).__init__(*args, **kwargs)
+    
+    @_needs_stage
+    def fetch(self):
+        super(URLMirrorFetchStrategy, self).fetch()
+        if self.digest:
+            try:
+                self.check()
+            except ChecksumError:
+                # Future fetchers will assume they don't need to download if the
+                # file remains
+                os.remove(self.archive_file)
+                raise
+
+
 class VCSFetchStrategy(FetchStrategy):
     def __init__(self, name, *rev_types, **kwargs):
         super(VCSFetchStrategy, self).__init__()
@@ -816,7 +835,7 @@ def store(self, copyCmd, relativeDst):
         
     def fetcher(self, targetPath, digest):
         url = "file://" + join_path(self.root, targetPath)
-        return URLFetchStrategy(url, digest)
+        return URLMirrorFetchStrategy(url, digest)
 
 
 class FetchError(spack.error.SpackError):
diff --git a/lib/spack/spack/mirror.py b/lib/spack/spack/mirror.py
index 81a2f6afb7..0bbcfba6b4 100644
--- a/lib/spack/spack/mirror.py
+++ b/lib/spack/spack/mirror.py
@@ -61,13 +61,7 @@ def mirror_archive_filename(spec, fetcher):
         # Otherwise we'll make a .tar.gz ourselves
         ext = 'tar.gz'
 
-    tokens = [spec.package.name, spec.version]
-    digests = spec.package.digests
-    if digests:
-        # If a package has multiple digests, any one is sufficient to identify it
-        digestType, digest = sorted(digests.iteritems())[0]
-        tokens.extend([digestType, digest])
-    filename = '-'.join(str(t) for t in tokens)
+    filename = "%s-%s" % (spec.package.name, spec.version)
     if ext:
         filename += ".%s" % ext
     return filename
diff --git a/lib/spack/spack/package.py b/lib/spack/spack/package.py
index 70ec243726..cbf50e56f6 100644
--- a/lib/spack/spack/package.py
+++ b/lib/spack/spack/package.py
@@ -413,15 +413,6 @@ def version(self):
             raise ValueError("Can only get of package with concrete version.")
         return self.spec.versions[0]
 
-    @property
-    def digests(self):
-        """All digests for the concretized package version."""
-        versionInfo = self.versions[self.version]
-        digests = {}
-        if 'md5' in versionInfo:
-            digests['md5'] = versionInfo['md5']
-        return digests 
-
     @memoized
     def version_urls(self):
         """Return a list of URLs for different versions of this