YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

//--------------------------------------------------------------------------------------------------

// Copyright (c) YugaByte, 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 "yb/yql/pggate/pg_memctx.h"

#include "yb/util/status.h"

#include "yb/yql/pggate/pg_tabledesc.h"

namespace yb {

namespace pggate {

PgMemctx::PgMemctx() {

}

PgMemctx::~PgMemctx() {

  Clear();

}

namespace {

  // Table of memory contexts.

  // - Although defined in Yugabyte, this table is owned and managed by Postgres process.

  //   Other processes cannot control "pggate::PgMemctx" to avoid memory violations.

  // - Table "postgres_process_memctxs" is to help releasing the references to PgStatement when

  //   Postgres Process (a C program) is exiting.

  // - Transaction layer and Postgres BOTH hold references to PgStatement objects, and those

  //   PgGate objects wouldn't be destroyed unless both layers release their references or both

  //   layers are terminated.

  std::unordered_map<PgMemctx *, PgMemctx::SharedPtr> postgres_process_memctxs;

} // namespace

PgMemctx *PgMemctx::Create() {

  auto memctx = std::make_shared<PgMemctx>();

  postgres_process_memctxs[memctx.get()] = memctx;

  return memctx.get();

}

Status PgMemctx::Destroy(PgMemctx *handle) {

  if (handle) {

    SCHECK(postgres_process_memctxs.find(handle) != postgres_process_memctxs.end(),

           InternalError, "Invalid memory context handle");

    postgres_process_memctxs.erase(handle);

  }

  return Status::OK();

}

Status PgMemctx::Reset(PgMemctx *handle) {

  if (handle) {

    SCHECK(postgres_process_memctxs.find(handle) != postgres_process_memctxs.end(),

           InternalError, "Invalid memory context handle");

    handle->Clear();

  }

  return Status::OK();

}

void PgMemctx::Register(Registrable *obj) {

  registered_objects_.push_back(*obj);

  obj->memctx_ = this;

}

void PgMemctx::Destroy(Registrable *obj) {

  auto& objs = obj->memctx_->registered_objects_;

  objs.erase_and_dispose(objs.iterator_to(*obj), std::default_delete<Registrable>());

}

void PgMemctx::Clear() {

  tabledesc_map_.clear();

  registered_objects_.clear_and_dispose(std::default_delete<Registrable>());

}

void PgMemctx::Cache(size_t hash_id, const PgTableDescPtr &table_desc) {

  // Add table descriptor to table.

  tabledesc_map_[hash_id] = table_desc;

}

void PgMemctx::GetCache(size_t hash_id, PgTableDesc **handle) {

  // Read table descriptor to table.

  const auto iter = tabledesc_map_.find(hash_id);

  if (iter == tabledesc_map_.end()) {

    *handle = nullptr;

  } else {

    *handle = iter->second.get();

  }

}

void ClearGlobalPgMemctxMap() {

  postgres_process_memctxs.clear();

}

}  // namespace pggate

}  // namespace yb