From 010670457359862da5622baa24d50f0d5bf42557 Mon Sep 17 00:00:00 2001
From: JackyWoo <wuchienchao@qq.com>
Date: Wed, 31 May 2023 16:31:06 +0800
Subject: [PATCH] add truncate to redis storage

---
 src/Storages/StorageRedis.cpp                | 11 +++---
 tests/integration/test_storage_redis/test.py | 37 ++++++++++++++++++++
 2 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/src/Storages/StorageRedis.cpp b/src/Storages/StorageRedis.cpp
index f9a25470e2d..dd33f6e6839 100644
--- a/src/Storages/StorageRedis.cpp
+++ b/src/Storages/StorageRedis.cpp
@@ -87,6 +87,7 @@ public:
         return storage.getBySerializedKeys(raw_keys, nullptr);
     }
 
+    /// TODO scan may get duplicated keys
     Chunk generateFullScan()
     {
         /// redis scan ending
@@ -480,17 +481,16 @@ SinkToStoragePtr StorageRedis::write(
     return std::make_shared<RedisSink>(*this, metadata_snapshot);
 }
 
-/// TODO use scan to reduce latency
 void StorageRedis::truncate(const ASTPtr &, const StorageMetadataPtr &, ContextPtr, TableExclusiveLockHolder &)
 {
     auto connection = getRedisConnection(pool, configuration);
 
     RedisCommand cmd_flush_db("FLUSHDB");
-    cmd_flush_db << toString(configuration.db_index);
-    auto ret = connection->client->execute<RedisBulkString>(cmd_flush_db);
+    cmd_flush_db.add("ASYNC");
+    auto ret = connection->client->execute<RedisSimpleString>(cmd_flush_db);
 
-    if (ret.isNull() || ret.value() != "OK")
-        throw Exception(ErrorCodes::INTERNAL_REDIS_ERROR, "Fail to truncate redis table {}, for {}", table_id.getFullNameNotQuoted(), ret.value());
+    if (ret != "OK")
+        throw Exception(ErrorCodes::INTERNAL_REDIS_ERROR, "Fail to truncate redis table {}, for {}", table_id.getFullNameNotQuoted(), ret);
 }
 
 void StorageRedis::checkMutationIsPossible(const MutationCommands & commands, const Settings & /* settings */) const
@@ -580,6 +580,7 @@ void StorageRedis::mutate(const MutationCommands & commands, ContextPtr context_
     }
 }
 
+/// TODO support ttl
 void registerStorageRedis(StorageFactory & factory)
 {
     StorageFactory::StorageFeatures features{
diff --git a/tests/integration/test_storage_redis/test.py b/tests/integration/test_storage_redis/test.py
index e77de99c649..ad1b0ada068 100644
--- a/tests/integration/test_storage_redis/test.py
+++ b/tests/integration/test_storage_redis/test.py
@@ -332,3 +332,40 @@ def test_delete(started_cluster):
     response = TSV.toMat(node.query("SELECT k, m, n FROM test_delete FORMAT TSV"))
     assert (len(response) == 0)
 
+
+def test_truncate(started_cluster):
+    client = get_redis_connection()
+    address = get_address_for_ch()
+    # clean all
+    client.flushall()
+    drop_table('test_truncate')
+
+    node.query(
+        f"""
+        CREATE TABLE test_truncate(
+            k UInt32, 
+            m DateTime,
+            n String
+        ) Engine=Redis('{address}', 0, 'clickhouse') PRIMARY KEY (k)
+        """
+    )
+
+    node.query(
+        """
+        INSERT INTO test_truncate Values 
+        (1, '2023-06-01 00:00:00', 'lili'), (2, '2023-06-02 00:00:00', 'lucy')
+        """
+    )
+
+    response = node.query(
+        """
+        TRUNCATE TABLE test_truncate
+        """
+    )
+
+    print("truncate table response: ",  response)
+
+    response = TSV.toMat(node.query("SELECT COUNT(*) FROM test_truncate FORMAT TSV"))
+    assert (len(response) == 1)
+    assert (response[0] == ['0'])
+