Merge "Disentangle BUCK caches for internally built and downloaded artifacts"

.buckconfig

diff --git a/.buckconfig b/.buckconfig
index 20954d7..7b75225 100644
--- a/.buckconfig
+++ b/.buckconfig
@@ -27,4 +27,4 @@
 
 [cache]
   mode = dir
-  dir = ~/.gerritcodereview/buck-cache/cache
+  dir = ~/.gerritcodereview/buck-cache/locally-built-artifacts

Documentation/dev-buck.txt

diff --git a/Documentation/dev-buck.txt b/Documentation/dev-buck.txt
index e307391..de3e6de 100644
--- a/Documentation/dev-buck.txt
+++ b/Documentation/dev-buck.txt
@@ -510,7 +510,7 @@
 === Cleaning The Buck Cache
 
 The cache for the Gerrit Code Review project is located in
-`~/.gerritcodereview/buck-cache/cache`.
+`~/.gerritcodereview/buck-cache/locally-built-artifacts`.
 
 The Buck cache should never need to be manually deleted. If you find yourself
 deleting the Buck cache regularly, then it is likely that there is something
@@ -519,11 +519,12 @@
 If you really do need to clean the cache manually, then:
 
 ----
- rm -rf ~/.gerritcodereview/buck-cache/cache
+ rm -rf ~/.gerritcodereview/buck-cache/locally-built-artifacts
 ----
 
-Note that the root `buck-cache` folder should not be deleted as this is where
-downloaded artifacts are stored.
+Note that the root `buck-cache` folder should not be deleted as it also contains
+the `downloaded-artifacts` directory, which holds the artifacts that got
+downloaded (not built locally).
 
 [[buck-daemon]]
 === Using Buck daemon

tools/download_file.py

diff --git a/tools/download_file.py b/tools/download_file.py
index 061d67c..97d982f 100755
--- a/tools/download_file.py
+++ b/tools/download_file.py
@@ -25,7 +25,11 @@
 from zipfile import ZipFile, BadZipfile, LargeZipFile
 
 GERRIT_HOME = path.expanduser('~/.gerritcodereview')
-CACHE_DIR = path.join(GERRIT_HOME, 'buck-cache')
+CACHE_DIR = path.join(GERRIT_HOME, 'buck-cache', 'downloaded-artifacts')
+# LEGACY_CACHE_DIR is only used to allow existing workspaces to move already
+# downloaded files to the new cache directory.
+# Please remove after 3 months (2015-10-07).
+LEGACY_CACHE_DIR = path.join(GERRIT_HOME, 'buck-cache')
 LOCAL_PROPERTIES = 'local.properties'
 
 
@@ -85,6 +89,15 @@
   name = '%s-%s' % (path.basename(args.o), h)
   return path.join(CACHE_DIR, name)
 
+# Please remove after 3 months (2015-10-07). See LEGACY_CACHE_DIR above.
+def legacy_cache_entry(args):
+  if args.v:
+    h = args.v
+  else:
+    h = sha1(args.u.encode('utf-8')).hexdigest()
+  name = '%s-%s' % (path.basename(args.o), h)
+  return path.join(LEGACY_CACHE_DIR, name)
+
 
 opts = OptionParser()
 opts.add_option('-o', help='local output file')
@@ -103,8 +116,19 @@
 
 redirects = download_properties(root_dir)
 cache_ent = cache_entry(args)
+legacy_cache_ent = legacy_cache_entry(args)
 src_url = resolve_url(args.u, redirects)
 
+# Please remove after 3 months (2015-10-07). See LEGACY_CACHE_DIR above.
+if not path.exists(cache_ent) and path.exists(legacy_cache_ent):
+  try:
+    safe_mkdirs(path.dirname(cache_ent))
+  except OSError as err:
+    print('error creating directory %s: %s' %
+          (path.dirname(cache_ent), err), file=stderr)
+    exit(1)
+  shutil.move(legacy_cache_ent, cache_ent)
+
 if not path.exists(cache_ent):
   try:
     safe_mkdirs(path.dirname(cache_ent))