From 5c7ec0622427a3ddd3dd2e8778332a3299537040 Mon Sep 17 00:00:00 2001
From: Roman Hargrave <roman@hargrave.info>
Date: Fri, 23 Dec 2022 20:06:18 -0800
Subject: [PATCH] Simplify S3 object name generation

The previous design used an extremely long prefix including a forward
slash that could have made managing uploaded objects extremely
difficult for operators.
---
 mod_s3_upload/src/mod_s3_upload.erl | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/mod_s3_upload/src/mod_s3_upload.erl b/mod_s3_upload/src/mod_s3_upload.erl
index 7af9a80..168dce7 100644
--- a/mod_s3_upload/src/mod_s3_upload.erl
+++ b/mod_s3_upload/src/mod_s3_upload.erl
@@ -447,16 +447,8 @@ object_url(BucketURL, FileName) ->
         FileName :: binary()
        ) ->
           ObjectName :: binary().
-% generate a unique-in-time object name. the name consists of a hash
-% derived from the file, node, time, and a random number, a
-% forward-slash, and the original filename. this ensures that it does
-% not collide with other objects, while the forward slash ensures that
-% the client displays only the original file name.
+% generate reasonably unique sortable (by time first) object name.
 object_name(FileName) ->
-    MD = crypto:hash_init(sha256),
-    MDFilename = crypto:hash_update(MD, FileName),
-    MDNodeName = crypto:hash_update(MDFilename, atom_to_list(node())),
-    MDTime = crypto:hash_update(MDNodeName, <<(os:system_time())>>),
-    MDRand = crypto:hash_update(MDTime, crypto:strong_rand_bytes(256)),
-    Hash = crypto:hash_final(MDRand),
-    <<(str:to_hexlist(Hash))/binary, "/", FileName/binary>>.
+    str:format("~.36B~.36B-~s", [os:system_time(microsecond),
+                                  erlang:phash2(node()),
+                                  FileName]).