ForeignStorageInterface.cpp

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/*
 * Copyright 2020 OmniSci, Inc.
 *
 * Licensed 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 "ForeignStorageInterface.h"
#include "Shared/StringTransform.h"

ForeignStorageBuffer::ForeignStorageBuffer(
    const ChunkKey& chunk_key,
    PersistentForeignStorageInterface* persistent_foreign_storage)
    : Data_Namespace::AbstractBuffer(0)
    , chunk_key_(chunk_key)
    , persistent_foreign_storage_(persistent_foreign_storage) {}

void ForeignStorageBuffer::read(int8_t* const dst,
                                const size_t numBytes,
                                const size_t offset,
                                const Data_Namespace::MemoryLevel dstBufferType,
                                const int dstDeviceId) {
  CHECK_EQ(size_t(0), offset);
  CHECK_EQ(-1, dstDeviceId);
  persistent_foreign_storage_->read(chunk_key_, sql_type_, dst, numBytes);
}

void ForeignStorageBuffer::append(int8_t* src,
                                  const size_t numBytes,
                                  const Data_Namespace::MemoryLevel srcBufferType,
                                  const int deviceId) {
  setAppended();
  buff_.insert(buff_.end(), src, src + numBytes);
  size_ += numBytes;
}

ForeignStorageBufferMgr::ForeignStorageBufferMgr(
    const int db_id,
    const int table_id,
    PersistentForeignStorageInterface* persistent_foreign_storage)
    : AbstractBufferMgr(0), persistent_foreign_storage_(persistent_foreign_storage) {}

void ForeignStorageBufferMgr::checkpoint() {
  // TODO(alex)
  std::vector<ForeignStorageColumnBuffer> column_buffers;
  for (auto& kv : chunk_index_) {
    const auto buffer = kv.second->moveBuffer();
    column_buffers.emplace_back(
        ForeignStorageColumnBuffer{kv.first, kv.second->getSqlType(), buffer});
  }
  persistent_foreign_storage_->append(column_buffers);
}

Data_Namespace::AbstractBuffer* ForeignStorageBufferMgr::createBuffer(
    const ChunkKey& key,
    const size_t pageSize,
    const size_t initialSize) {
  mapd_unique_lock<mapd_shared_mutex> chunk_index_write_lock(chunk_index_mutex_);
  const auto it_ok = chunk_index_.emplace(
      key, std::make_unique<ForeignStorageBuffer>(key, persistent_foreign_storage_));
  // this check fails if we create table, drop it and create again
  // CHECK(it_ok.second);
  return it_ok.first->second.get();
}

Data_Namespace::AbstractBuffer* ForeignStorageBufferMgr::getBuffer(
    const ChunkKey& key,
    const size_t numBytes) {
  mapd_shared_lock<mapd_shared_mutex> chunk_index_write_lock(chunk_index_mutex_);
  const auto it = chunk_index_.find(key);
  CHECK(it != chunk_index_.end());
  return it->second.get();
}

void ForeignStorageBufferMgr::fetchBuffer(const ChunkKey& key,
                                          Data_Namespace::AbstractBuffer* destBuffer,
                                          const size_t numBytes) {
  CHECK(numBytes);
  destBuffer->reserve(numBytes);
  auto file_buffer = getBuffer(key, numBytes);
  file_buffer->read(destBuffer->getMemoryPtr(), numBytes);
  destBuffer->setSize(numBytes);
  destBuffer->syncEncoder(file_buffer);
}

void ForeignStorageBufferMgr::getChunkMetadataVecForKeyPrefix(
    ChunkMetadataVector& chunkMetadataVec,
    const ChunkKey& keyPrefix) {
  mapd_unique_lock<mapd_shared_mutex> chunk_index_write_lock(
      chunk_index_mutex_);  // is this guarding the right structure?  it look slike we
                            // oly read here for chunk
  auto chunk_it = chunk_index_.lower_bound(keyPrefix);
  if (chunk_it == chunk_index_.end()) {
    CHECK(false);  // throw?
  }

  while (chunk_it != chunk_index_.end() &&
         std::search(chunk_it->first.begin(),
                     chunk_it->first.begin() + keyPrefix.size(),
                     keyPrefix.begin(),
                     keyPrefix.end()) != chunk_it->first.begin() + keyPrefix.size()) {
    const auto& chunk_key = chunk_it->first;
    if (chunk_key.size() == 5) {
      if (chunk_key[4] == 1) {
        const auto& buffer = *chunk_it->second;
        auto type = buffer.getSqlType();
        auto size = buffer.size();
        auto subkey = chunk_key;
        subkey[4] = 2;
        auto& index_buf = *(chunk_index_.find(subkey)->second);
        auto bs = index_buf.size() / index_buf.getSqlType().get_size();
        auto chunk_metadata =
            std::make_shared<ChunkMetadata>(type, size, bs, ChunkStats{});
        chunkMetadataVec.emplace_back(chunk_key, chunk_metadata);
      }
    } else {
      const auto& buffer = *chunk_it->second;
      auto chunk_metadata = std::make_shared<ChunkMetadata>();
      chunk_metadata->sqlType = buffer.getSqlType();
      buffer.getEncoder()->getMetadata(chunk_metadata);
      chunkMetadataVec.emplace_back(chunk_key, chunk_metadata);
    }
    chunk_it++;
  }
}

Data_Namespace::AbstractBufferMgr* ForeignStorageInterface::lookupBufferManager(
    const int db_id,
    const int table_id) {
  auto key = std::make_pair(db_id, table_id);
  if (managers_map_.count(key)) {
    return managers_map_[key].get();
  }

  std::lock_guard<std::mutex> persistent_storage_interfaces_lock(
      persistent_storage_interfaces_mutex_);
  const auto it = table_persistent_storage_interface_map_.find(key);
  if (it == table_persistent_storage_interface_map_.end()) {
    return nullptr;
  }
  const auto it_ok = managers_map_.emplace(
      key, std::make_unique<ForeignStorageBufferMgr>(db_id, table_id, it->second));
  CHECK(it_ok.second);
  return it_ok.first->second.get();
}

void ForeignStorageInterface::registerPersistentStorageInterface(
    std::unique_ptr<PersistentForeignStorageInterface> persistent_foreign_storage) {
  std::lock_guard<std::mutex> persistent_storage_interfaces_lock(
      persistent_storage_interfaces_mutex_);
  const auto it_ok = persistent_storage_interfaces_.emplace(
      persistent_foreign_storage->getType(), std::move(persistent_foreign_storage));
  CHECK(it_ok.second);
}

std::pair<std::string, std::string> parseStorageType(const std::string& type) {
  size_t sep = type.find_first_of(':'), sep2 = sep != std::string::npos ? sep + 1 : sep;
  auto res = std::make_pair(to_upper(type.substr(0, sep)), type.substr(sep2));
  return res;
}

void ForeignStorageInterface::prepareTable(const int db_id,
                                           TableDescriptor& td,
                                           std::list<ColumnDescriptor>& cols) {
  auto type = parseStorageType(td.storageType);
  std::unique_lock<std::mutex> persistent_storage_interfaces_lock(
      persistent_storage_interfaces_mutex_);
  const auto it = persistent_storage_interfaces_.find(type.first);
  if (it == persistent_storage_interfaces_.end()) {
    throw std::runtime_error("storage type " + type.first + " not supported");
  }
  auto& p = it->second;
  persistent_storage_interfaces_lock.unlock();
  p->prepareTable(db_id, type.second, td, cols);
}

void ForeignStorageInterface::registerTable(Catalog_Namespace::Catalog* catalog,
                                            const TableDescriptor& td,
                                            const std::list<ColumnDescriptor>& cols) {
  const int table_id = td.tableId;
  auto type = parseStorageType(td.storageType);

  std::unique_lock<std::mutex> persistent_storage_interfaces_lock(
      persistent_storage_interfaces_mutex_);
  const auto it = persistent_storage_interfaces_.find(type.first);
  if (it == persistent_storage_interfaces_.end()) {
    throw std::runtime_error("storage type " + type.first + " not supported");
  }

  auto db_id = catalog->getCurrentDB().dbId;
  const auto it_ok = table_persistent_storage_interface_map_.emplace(
      std::make_pair(db_id, table_id), it->second.get());
  // this check fails if we create table, drop it and create again
  // CHECK(it_ok.second);
  persistent_storage_interfaces_lock.unlock();
  it_ok.first->second->registerTable(catalog,
                                     it_ok.first->first,
                                     type.second,
                                     td,
                                     cols,
                                     lookupBufferManager(db_id, table_id));
}

void ForeignStorageInterface::destroy() {
  persistent_storage_interfaces_.clear();
  managers_map_.clear();
}

std::unordered_map<std::string, std::unique_ptr<PersistentForeignStorageInterface>>
    ForeignStorageInterface::persistent_storage_interfaces_;
std::map<std::pair<int, int>, PersistentForeignStorageInterface*>
    ForeignStorageInterface::table_persistent_storage_interface_map_;
std::map<std::pair<int, int>, std::unique_ptr<ForeignStorageBufferMgr>>
    ForeignStorageInterface::managers_map_;
std::mutex ForeignStorageInterface::persistent_storage_interfaces_mutex_;