// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you under the Apache License, Version 2.0 (the

// "License"); you may not use this file except in compliance

// with the License.  You may obtain a copy of the License at

//

//   http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing,

// software distributed under the License is distributed on an

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied.  See the License for the

// specific language governing permissions and limitations

// under the License.

#include "storage/tablet/tablet_schema_cache.h"

#include <gen_cpp/olap_file.pb.h>

#include <glog/logging.h>

#include <json2pb/pb_to_json.h>

#include "bvar/bvar.h"

#include "storage/tablet/tablet_schema.h"

#include "util/sha.h"

bvar::Adder<int64_t> g_tablet_schema_cache_count("tablet_schema_cache_count");

bvar::Adder<int64_t> g_tablet_schema_cache_columns_count("tablet_schema_cache_columns_count");

bvar::Adder<int64_t> g_tablet_schema_cache_hit_count("tablet_schema_cache_hit_count");

namespace doris {

// to reduce the memory consumption of the serialized TabletSchema as key.

// use sha256 to prevent from hash collision

static std::string get_key_signature(const std::string& origin) {

    SHA256Digest digest;

    digest.reset(origin.data(), origin.length());

    return std::string {digest.digest().data(), digest.digest().length()};

}

std::pair<Cache::Handle*, TabletSchemaSPtr> TabletSchemaCache::insert(const std::string& key) {

    std::string key_signature = get_key_signature(key);

    auto* lru_handle = lookup(key_signature);

    TabletSchemaSPtr tablet_schema_ptr;

    if (lru_handle) {

        auto* value = (CacheValue*)LRUCachePolicy::value(lru_handle);

        tablet_schema_ptr = value->tablet_schema;

        g_tablet_schema_cache_hit_count << 1;

    } else {

        auto* value = new CacheValue;

        tablet_schema_ptr = std::make_shared<TabletSchema>();

        TabletSchemaPB pb;

        pb.ParseFromString(key);

        // We should reuse the memory of the same TabletColumn/TabletIndex object, set reuse_cached_column to true

        tablet_schema_ptr->init_from_pb(pb, false, true);

        value->tablet_schema = tablet_schema_ptr;

        lru_handle = LRUCachePolicy::insert(key_signature, value, tablet_schema_ptr->num_columns(),

                                            tablet_schema_ptr->mem_size(), CachePriority::NORMAL);

        g_tablet_schema_cache_count << 1;

        g_tablet_schema_cache_columns_count << tablet_schema_ptr->num_columns();

    }

    DCHECK(lru_handle != nullptr);

    return std::make_pair(lru_handle, tablet_schema_ptr);

}

void TabletSchemaCache::release(Cache::Handle* lru_handle) {

    LRUCachePolicy::release(lru_handle);

}

TabletSchemaCache::CacheValue::~CacheValue() {

    g_tablet_schema_cache_count << -1;

    g_tablet_schema_cache_columns_count << -tablet_schema->num_columns();

}

} // namespace doris