From 8c9df30e28a3b95efe537afe9930de2150999441 Mon Sep 17 00:00:00 2001
From: Jack Zampolin <jack.zampolin@gmail.com>
Date: Mon, 4 Mar 2019 22:56:46 -0800
Subject: [PATCH] libs/db: Add cleveldb.Stats() (#3379)

Fixes: #3378

* Add stats to cleveldb implementation

* update changelog

* remote TODO

also
- sort keys
- preallocate memory

* fix const initializer []string literal is not a constant

* add test
---
 CHANGELOG_PENDING.md       |  9 +++++++++
 libs/db/c_level_db.go      | 14 +++++++++++---
 libs/db/c_level_db_test.go |  9 +++++++++
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG_PENDING.md b/CHANGELOG_PENDING.md
index fe9a87d8a..cbb4077c7 100644
--- a/CHANGELOG_PENDING.md
+++ b/CHANGELOG_PENDING.md
@@ -30,6 +30,15 @@ Special thanks to external contributors on this release:
 
 ### IMPROVEMENTS:
 - [libs/common] \#3238 exit with zero (0) code upon receiving SIGTERM/SIGINT
+- [libs/db] \#3378 CLevelDB#Stats now returns the following properties:
+  - leveldb.num-files-at-level{n}
+  - leveldb.stats
+  - leveldb.sstables
+  - leveldb.blockpool
+  - leveldb.cachedblock
+  - leveldb.openedtables
+  - leveldb.alivesnaps
+  - leveldb.aliveiters
 
 ### BUG FIXES:
 
diff --git a/libs/db/c_level_db.go b/libs/db/c_level_db.go
index 7f74b2a71..e411dfdd0 100644
--- a/libs/db/c_level_db.go
+++ b/libs/db/c_level_db.go
@@ -128,10 +128,18 @@ func (db *CLevelDB) Print() {
 
 // Implements DB.
 func (db *CLevelDB) Stats() map[string]string {
-	// TODO: Find the available properties for the C LevelDB implementation
-	keys := []string{}
+	keys := []string{
+		"leveldb.aliveiters",
+		"leveldb.alivesnaps",
+		"leveldb.blockpool",
+		"leveldb.cachedblock",
+		"leveldb.num-files-at-level{n}",
+		"leveldb.openedtables",
+		"leveldb.sstables",
+		"leveldb.stats",
+	}
 
-	stats := make(map[string]string)
+	stats := make(map[string]string, len(keys))
 	for _, key := range keys {
 		str := db.db.PropertyValue(key)
 		stats[key] = str
diff --git a/libs/db/c_level_db_test.go b/libs/db/c_level_db_test.go
index eab3dfc41..e71dee0c1 100644
--- a/libs/db/c_level_db_test.go
+++ b/libs/db/c_level_db_test.go
@@ -99,3 +99,12 @@ func TestCLevelDBBackend(t *testing.T) {
 	_, ok := db.(*CLevelDB)
 	assert.True(t, ok)
 }
+
+func TestCLevelDBStats(t *testing.T) {
+	name := fmt.Sprintf("test_%x", cmn.RandStr(12))
+	dir := os.TempDir()
+	db := NewDB(name, LevelDBBackend, dir)
+	defer cleanupDBDir(dir, name)
+
+	assert.NotEmpty(t, db.Stats())
+}