From 3897af4a8f5c1e4d29e0ef7a4ea271c0c572df2a Mon Sep 17 00:00:00 2001
From: Casey Bodley <cbodley@redhat.com>
Date: Mon, 12 Nov 2018 18:45:14 -0500
Subject: [PATCH] cls/log: cls_log_trim() uses cls_cxx_map_remove_range()

uses cls_cxx_map_get_keys() instead of cls_cxx_map_get_vals() to limit
the number of keys removed

Signed-off-by: Casey Bodley <cbodley@redhat.com>
---
 src/cls/log/cls_log.cc | 58 ++++++++++++++++++++++--------------------
 1 file changed, 30 insertions(+), 28 deletions(-)

diff --git a/src/cls/log/cls_log.cc b/src/cls/log/cls_log.cc
index 3de35484cb7..ad3de9499fa 100644
--- a/src/cls/log/cls_log.cc
+++ b/src/cls/log/cls_log.cc
@@ -216,12 +216,10 @@ static int cls_log_trim(cls_method_context_t hctx, bufferlist *in, bufferlist *o
   try {
     decode(op, in_iter);
   } catch (buffer::error& err) {
-    CLS_LOG(0, "ERROR: cls_log_list_op(): failed to decode entry");
+    CLS_LOG(0, "ERROR: cls_log_trim(): failed to decode entry");
     return -EINVAL;
   }
 
-  map<string, bufferlist> keys;
-
   string from_index;
   string to_index;
 
@@ -230,44 +228,48 @@ static int cls_log_trim(cls_method_context_t hctx, bufferlist *in, bufferlist *o
   } else {
     from_index = op.from_marker;
   }
+
+  // cls_cxx_map_remove_range() expects one-past-end
   if (op.to_marker.empty()) {
-    get_index_time_prefix(op.to_time, to_index);
+    auto t = op.to_time;
+    t.nsec_ref() += 1000; // equivalent to usec() += 1
+    t.normalize();
+    get_index_time_prefix(t, to_index);
   } else {
     to_index = op.to_marker;
+    to_index.append(1, '\0');
   }
 
-#define MAX_TRIM_ENTRIES 1000
-  size_t max_entries = MAX_TRIM_ENTRIES;
-  bool more;
+  // list a single key to detect whether the range is empty
+  const size_t max_entries = 1;
+  std::set<std::string> keys;
+  bool more = false;
 
-  int rc = cls_cxx_map_get_vals(hctx, from_index, log_index_prefix, max_entries, &keys, &more);
-  if (rc < 0)
+  int rc = cls_cxx_map_get_keys(hctx, from_index, max_entries, &keys, &more);
+  if (rc < 0) {
+    CLS_LOG(1, "ERROR: cls_cxx_map_get_keys failed rc=%d", rc);
     return rc;
+  }
 
-  map<string, bufferlist>::iterator iter = keys.begin();
-
-  bool removed = false;
-  for (; iter != keys.end(); ++iter) {
-    const string& index = iter->first;
-
-    CLS_LOG(20, "index=%s to_index=%s", index.c_str(), to_index.c_str());
+  if (keys.empty()) {
+    CLS_LOG(20, "range is empty from_index=%s", from_index.c_str());
+    return -ENODATA;
+  }
 
-    if (index.compare(0, to_index.size(), to_index) > 0)
-      break;
+  const std::string& first_key = *keys.begin();
+  if (to_index < first_key) {
+    CLS_LOG(20, "listed key %s past to_index=%s", first_key.c_str(), to_index.c_str());
+    return -ENODATA;
+  }
 
-    CLS_LOG(20, "removing key: index=%s", index.c_str());
+  CLS_LOG(20, "listed key %s, removing through %s", first_key.c_str(), to_index.c_str());
 
-    int rc = cls_cxx_map_remove_key(hctx, index);
-    if (rc < 0) {
-      CLS_LOG(1, "ERROR: cls_cxx_map_remove_key failed rc=%d", rc);
-      return -EINVAL;
-    }
-    removed = true;
+  rc = cls_cxx_map_remove_range(hctx, first_key, to_index);
+  if (rc < 0) {
+    CLS_LOG(1, "ERROR: cls_cxx_map_remove_range failed rc=%d", rc);
+    return rc;
   }
 
-  if (!removed)
-    return -ENODATA;
-
   return 0;
 }
 
-- 
2.39.5