From 82d2d612e700f94a0bb2d9fb7555abf327be379b Mon Sep 17 00:00:00 2001
From: Yehuda Sadeh <yehuda@inktank.com>
Date: Thu, 17 Jul 2014 11:45:44 -0700
Subject: [PATCH] rgw: account common prefixes for MaxKeys in bucket listing

To be more in line with the S3 api. Beforehand we didn't account the
common prefixes towards the MaxKeys (a single common prefix counts as a
single key). Also need to adjust the marker now if it is pointing at a
common prefix.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
---
 src/rgw/rgw_rados.cc | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/src/rgw/rgw_rados.cc b/src/rgw/rgw_rados.cc
index ea33bfbc784b8..383976557f6e3 100644
--- a/src/rgw/rgw_rados.cc
+++ b/src/rgw/rgw_rados.cc
@@ -2257,7 +2257,7 @@ int RGWRados::list_objects(rgw_bucket& bucket, int max, string& prefix, string&
                            bool *is_truncated, RGWAccessListFilter *filter)
 {
   int count = 0;
-  bool truncated;
+  bool truncated = true;
 
   if (bucket_is_system(bucket)) {
     return -EINVAL;
@@ -2290,7 +2290,16 @@ int RGWRados::list_objects(rgw_bucket& bucket, int max, string& prefix, string&
 
   string skip_after_delim;
 
-  do {
+  /* if marker points at a common prefix, fast forward it into its upperbound string */
+  if (!delim.empty()) {
+    int delim_pos = cur_marker.find(delim, prefix.size());
+    if (delim_pos >= 0) {
+      cur_marker = cur_marker.substr(0, delim_pos);
+      cur_marker.append(bigger_than_delim);
+    }
+  }
+
+  while (truncated && count < max) {
     if (skip_after_delim > cur_marker) {
       cur_marker = skip_after_delim;
       ldout(cct, 20) << "setting cur_marker=" << cur_marker << dendl;
@@ -2333,12 +2342,21 @@ int RGWRados::list_objects(rgw_bucket& bucket, int max, string& prefix, string&
         int delim_pos = obj.find(delim, prefix.size());
 
         if (delim_pos >= 0) {
-          common_prefixes[obj.substr(0, delim_pos + 1)] = true;
+          string prefix_key = obj.substr(0, delim_pos + 1);
+
+          if (common_prefixes.find(prefix_key) == common_prefixes.end()) {
+            if (next_marker) {
+              *next_marker = prefix_key;
+            }
+            common_prefixes[prefix_key] = true;
 
-          skip_after_delim = obj.substr(0, delim_pos);
-          skip_after_delim.append(bigger_than_delim);
+            skip_after_delim = obj.substr(0, delim_pos);
+            skip_after_delim.append(bigger_than_delim);
 
-          ldout(cct, 20) << "skip_after_delim=" << skip_after_delim << dendl;
+            ldout(cct, 20) << "skip_after_delim=" << skip_after_delim << dendl;
+
+            count++;
+          }
 
           continue;
         }
@@ -2350,7 +2368,7 @@ int RGWRados::list_objects(rgw_bucket& bucket, int max, string& prefix, string&
       result.push_back(ent);
       count++;
     }
-  } while (truncated && count < max);
+  }
 
 done:
   if (is_truncated)
-- 
2.39.5