ClickHouse/src/Common/FileCacheFactory.cpp

#include "FileCacheFactory.h"
#include "FileCache.h"

namespace DB
{

namespace ErrorCodes
{
    extern const int BAD_ARGUMENTS;
}

FileCacheFactory & FileCacheFactory::instance()
{
    static FileCacheFactory ret;
    return ret;
}

FileCacheFactory::CacheByBasePath FileCacheFactory::getAll()
{
    std::lock_guard lock(mutex);
    return caches;
}

FileCachePtr FileCacheFactory::getImpl(const std::string & cache_base_path, std::lock_guard<std::mutex> &)
{
    auto it = caches.find(cache_base_path);
    if (it == caches.end())
        return nullptr;
    return it->second;
}

FileCachePtr FileCacheFactory::get(const std::string & cache_base_path)
{
    std::lock_guard lock(mutex);
    auto cache = getImpl(cache_base_path, lock);
    if (cache)
        return cache;

    throw Exception(ErrorCodes::BAD_ARGUMENTS, "No cache found by path: {}", cache_base_path);
}

FileCachePtr FileCacheFactory::getOrCreate(
    const std::string & cache_base_path, const FileCacheSettings & file_cache_settings)
{
    std::lock_guard lock(mutex);
    auto cache = getImpl(cache_base_path, lock);
    if (cache)
        return cache;

    cache = std::make_shared<LRUFileCache>(cache_base_path, file_cache_settings);
    caches.emplace(cache_base_path, cache);
    return cache;
}

}