From 041e760440682af7640d75ed6de3365307dcb062 Mon Sep 17 00:00:00 2001
From: xinxinsh <xinxin.shu@intel.com>
Date: Mon, 31 Mar 2014 17:55:16 -0700
Subject: [PATCH] os/KeyValueDB: generic create(), test_init()

Let us create an implemenetation by name.  Include a test_init() method
that will instantiate an instance and verify it could start up.

Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 4bf929ef21b6710f60f01cb8f7095ad0a440709f)
---
 src/os/KeyValueDB.cc   | 32 ++++++++++++++++++++++++++++++++
 src/os/KeyValueDB.h    |  6 ++++++
 src/os/LevelDBStore.cc | 10 ++++++++++
 src/os/LevelDBStore.h  |  1 +
 src/os/Makefile.am     |  1 +
 5 files changed, 50 insertions(+)
 create mode 100644 src/os/KeyValueDB.cc

diff --git a/src/os/KeyValueDB.cc b/src/os/KeyValueDB.cc
new file mode 100644
index 0000000..8e590e2
--- /dev/null
+++ b/src/os/KeyValueDB.cc
@@ -0,0 +1,32 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "KeyValueDB.h"
+#include "LevelDBStore.h"
+
+KeyValueDB *KeyValueDB::create(CephContext *cct, const string& type,
+			       const string& dir)
+{
+  if (type == "leveldb") {
+    return new LevelDBStore(cct, dir);
+  }
+#ifdef HAVE_KINETIC
+  if (kv_type == KV_TYPE_KINETIC) {
+    store = new KineticStore(g_ceph_context);
+  }
+#endif
+  return NULL;
+}
+
+int KeyValueDB::test_init(const string& type, const string& dir)
+{
+  if (type == "leveldb"){
+    return LevelDBStore::_test_init(dir);
+  }
+#ifdef HAVE_KINETIC
+  if (kv_type == KV_TYPE_KINETIC) {
+    return 0;
+  }
+#endif
+  return -EINVAL;
+}
diff --git a/src/os/KeyValueDB.h b/src/os/KeyValueDB.h
index c581aa5..f8e0b68 100644
--- a/src/os/KeyValueDB.h
+++ b/src/os/KeyValueDB.h
@@ -64,6 +64,12 @@ public:
   };
   typedef ceph::shared_ptr< TransactionImpl > Transaction;
 
+  /// create a new instance
+  static KeyValueDB *create(CephContext *cct, const string& type,
+			    const string& dir);
+
+  /// test whether we can successfully initialize; may have side effects (e.g., create)
+  static int test_init(const string& type, const string& dir);
   virtual int init() = 0;
   virtual int open(ostream &out) = 0;
   virtual int create_and_open(ostream &out) = 0;
diff --git a/src/os/LevelDBStore.cc b/src/os/LevelDBStore.cc
index 326862f..818396a 100644
--- a/src/os/LevelDBStore.cc
+++ b/src/os/LevelDBStore.cc
@@ -92,6 +92,16 @@ int LevelDBStore::do_open(ostream &out, bool create_if_missing)
   return 0;
 }
 
+int LevelDBStore::_test_init(const string& dir)
+{
+  leveldb::Options options;
+  options.create_if_missing = true;
+  leveldb::DB *db;
+  leveldb::Status status = leveldb::DB::Open(options, dir, &db);
+  delete db;
+  return status.ok() ? 0 : -EIO;
+}
+
 LevelDBStore::~LevelDBStore()
 {
   close();
diff --git a/src/os/LevelDBStore.h b/src/os/LevelDBStore.h
index 26e7bbe..1c072da 100644
--- a/src/os/LevelDBStore.h
+++ b/src/os/LevelDBStore.h
@@ -154,6 +154,7 @@ public:
 
   ~LevelDBStore();
 
+  static int _test_init(const string& dir);
   int init();
 
   /// Opens underlying db
diff --git a/src/os/Makefile.am b/src/os/Makefile.am
index 39bbdb2..f2303fb 100644
--- a/src/os/Makefile.am
+++ b/src/os/Makefile.am
@@ -18,6 +18,7 @@ libos_la_SOURCES = \
 	os/LevelDBStore.cc \
 	os/LFNIndex.cc \
 	os/MemStore.cc \
+	os/KeyValueDB.cc \
 	os/KeyValueStore.cc \
 	os/ObjectStore.cc \
 	os/WBThrottle.cc \
-- 
1.9.3