S3: Add fileprefix setting.

Remote/S3.hs

@@ -212,9 +212,11 @@ s3Action r noconn action = do
 bucketFile :: Remote -> Key -> FilePath
 bucketFile r = munge . show
 	where
-		munge s = case M.lookup "mungekeys" $ fromJust $ config r of
-			Just "ia" -> iaMunge s
-			_ -> s
+		munge s = case M.lookup "mungekeys" c of
+			Just "ia" -> iaMunge $ prefix ++ s
+			_ -> prefix ++ s
+		prefix = M.findWithDefault "" "fileprefix" c
+		c = fromJust $ config r
 
 bucketKey :: Remote -> String -> Key -> S3Object
 bucketKey r bucket k = S3Object bucket (bucketFile r k) "" [] L.empty

debian/changelog

@@ -1,3 +1,9 @@
+git-annex (3.20120808) UNRELEASED; urgency=low
+
+  * S3: Add fileprefix setting.
+
+ -- Joey Hess <joeyh@debian.org>  Thu, 09 Aug 2012 13:51:47 -0400
+
 git-annex (3.20120807) unstable; urgency=low
 
   * initremote: Avoid recording remote's description before checking

doc/special_remotes/S3.mdwn

@@ -36,5 +36,11 @@ the S3 remote.
   so by default, a bucket name is chosen based on the remote name
   and UUID. This can be specified to pick a bucket name.
 
+* `fileprefix` - By default, git-annex places files in a tree rooted at the
+  top of the S3 bucket. When this is set, it's prefixed to the filenames
+  used. For example, you could set it to "foo/" in one special remote,
+  and to "bar/" in another special remote, and both special remotes could
+  then use the same bucket.
+
 * `x-amz-*` are passed through as http headers when storing keys
   in S3.