From 0d99a5da3caa5a35ccc6048e6ec995487379e61e Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Wed, 2 Sep 2020 18:39:24 -0700
Subject: [PATCH] c*: support kv operations

---
 weed/filer/cassandra/cassandra_store_kv.go | 51 ++++++++++++++++++++--
 1 file changed, 47 insertions(+), 4 deletions(-)

diff --git a/weed/filer/cassandra/cassandra_store_kv.go b/weed/filer/cassandra/cassandra_store_kv.go
index f7668746f..b6238cf0e 100644
--- a/weed/filer/cassandra/cassandra_store_kv.go
+++ b/weed/filer/cassandra/cassandra_store_kv.go
@@ -2,17 +2,60 @@ package cassandra
 
 import (
 	"context"
+	"fmt"
 	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/gocql/gocql"
 )
 
 func (store *CassandraStore) KvPut(ctx context.Context, key []byte, value []byte) (err error) {
-	return filer.ErrKvNotImplemented
+	dir, name := genDirAndName(key)
+
+	if err := store.session.Query(
+		"INSERT INTO filemeta (directory,name,meta) VALUES(?,?,?) USING TTL ? ",
+		dir, name, value, 0).Exec(); err != nil {
+		return fmt.Errorf("kv insert: %s", err)
+	}
+
+	return nil
 }
 
-func (store *CassandraStore) KvGet(ctx context.Context, key []byte) (value []byte, err error) {
-	return nil, filer.ErrKvNotImplemented
+func (store *CassandraStore) KvGet(ctx context.Context, key []byte) (data []byte, err error) {
+	dir, name := genDirAndName(key)
+
+	if err := store.session.Query(
+		"SELECT meta FROM filemeta WHERE directory=? AND name=?",
+		dir, name).Consistency(gocql.One).Scan(&data); err != nil {
+		if err != gocql.ErrNotFound {
+			return nil, filer.ErrKvNotFound
+		}
+	}
+
+	if len(data) == 0 {
+		return nil, filer.ErrKvNotFound
+	}
+
+	return data, nil
 }
 
 func (store *CassandraStore) KvDelete(ctx context.Context, key []byte) (err error) {
-	return filer.ErrKvNotImplemented
+	dir, name := genDirAndName(key)
+
+	if err := store.session.Query(
+		"DELETE FROM filemeta WHERE directory=? AND name=?",
+		dir, name).Exec(); err != nil {
+		return fmt.Errorf("kv delete: %v", err)
+	}
+
+	return nil
+}
+
+func genDirAndName(key []byte) (dir string, name string) {
+	for len(key) < 8 {
+		key = append(key, 0)
+	}
+
+	dir = string(key[:8])
+	name = string(key[8:])
+
+	return
 }