add a func to get the version of the loaded leveldb

README.md

@@ -13,7 +13,7 @@ You'll need the shared library build of
 [LevelDB](http://code.google.com/p/leveldb/) installed on your machine. The
 current LevelDB will build it by default.
 
-The minimum version of LevelDB required is currently 1.6. If you require the
+The minimum version of LevelDB required is currently 1.7. If you require the
 use of an older version of LevelDB, see the [fork of levigo for LevelDB
 1.4](https://github.com/jmhodges/levigo_leveldb_1.4). Prefer putting in the
 work to be up to date as LevelDB moves very quickly.

leveldb_test.go

@@ -16,6 +16,10 @@ func init() {
 
 // This testcase is a port of leveldb's c_test.c.
 func TestC(t *testing.T) {
+	if GetLevelDBMajorVersion() <= 0 {
+		t.Errorf("Major version cannot be less than zero")
+	}
+
 	dbname := tempDir(t)
 	defer deleteDBDirectory(t, dbname)
 	env := NewDefaultEnv()

version.go

@@ -0,0 +1,15 @@
+package levigo
+
+/*
+#cgo LDFLAGS: -lleveldb
+#include "leveldb/c.h"
+*/
+import "C"
+
+func GetLevelDBMajorVersion() int {
+	return int(C.leveldb_major_version())
+}
+
+func GetLevelDBMinorVersion() int {
+	return int(C.leveldb_minor_version())
+}