Merge pull request ceph#4 from branch-predictor/wip-kv

kv/LevelDBStore, FileStore, MonDBStore: simpler code for single-key fetches
branch-predictor · Oct 23, 2015 · 574f3fc · 574f3fc
2 parents daa4041 + 6b6c5da
commit 574f3fc
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Showing 4 changed files with 33 additions and 13 deletions.
diff --git a/src/kv/LevelDBStore.cc b/src/kv/LevelDBStore.cc
@@ -229,6 +229,25 @@ int LevelDBStore::get(
   return 0;
 }
 
+int LevelDBStore::get(const string &prefix, 
+		  const string &key,
+		  bufferlist *value)
+{
+  utime_t start = ceph_clock_now(g_ceph_context);
+  int r = 0;
+  KeyValueDB::Iterator it = get_iterator(prefix);
+  it->lower_bound(key);
+  if (it->valid() && it->key() == key) {
+    *value = it->value();
+  } else {
+    r = -ENOENT;
+  }
+  utime_t lat = ceph_clock_now(g_ceph_context) - start;
+  logger->inc(l_leveldb_gets);
+  logger->tinc(l_leveldb_get_latency, lat);
+  return r;
+}
+
 string LevelDBStore::combine_strings(const string &prefix, const string &value)
 {
   string out = prefix;

diff --git a/src/kv/LevelDBStore.h b/src/kv/LevelDBStore.h
@@ -205,6 +205,10 @@ class LevelDBStore : public KeyValueDB {
     std::map<string, bufferlist> *out
     );
 
+  int get(const string &prefix, 
+    const string &key,   
+    bufferlist *value);
+
   class LevelDBWholeSpaceIteratorImpl :
     public KeyValueDB::WholeSpaceIteratorImpl {
   protected:

diff --git a/src/mon/MonitorDBStore.h b/src/mon/MonitorDBStore.h
@@ -507,14 +507,12 @@ class MonitorDBStore
   }
 
   int get(const string& prefix, const string& key, bufferlist& bl) {
-    set<string> k;
-    k.insert(key);
-    map<string,bufferlist> out;
-
-    db->get(prefix, k, &out);
-    if (out.empty())
+
+    bufferlist outbl;
+    db->get(prefix, key, &outbl);
+    if (outbl.length() == 0) 
       return -ENOENT;
-    bl.append(out[key]);
+    bl.append(outbl);
 
     return 0;
   }

diff --git a/src/os/DBObjectMap.cc b/src/os/DBObjectMap.cc
@@ -1089,17 +1089,16 @@ DBObjectMap::Header DBObjectMap::_lookup_map_header(
     }
   }
 
-  map<string, bufferlist> out;
-  set<string> to_get;
-  to_get.insert(map_header_key(oid));
-  int r = db->get(HOBJECT_TO_SEQ, to_get, &out);
-  if (r < 0 || out.empty()) {
+  bufferlist out;
+  int r = db->get(HOBJECT_TO_SEQ, map_header_key(oid), &out);
+  if (r < 0 || out.length()==0) {
     delete header;
     return Header();
   }
 
   Header ret(header, RemoveOnDelete(this));
-  bufferlist::iterator iter = out.begin()->second.begin();
+  bufferlist::iterator iter = out.begin();
+
   ret->decode(iter);
   {
     Mutex::Locker l(cache_lock);