tasks/common/persistence/sql/sqlplugin/postgresql/shard.go

// The MIT License
//
// Copyright (c) 2020 Temporal Technologies Inc.  All rights reserved.
//
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package postgresql

import (
	"context"
	"database/sql"

	"go.temporal.io/server/common/persistence/sql/sqlplugin"
)

const (
	createShardQry = `INSERT INTO
 shards (shard_id, range_id, data, data_encoding) VALUES ($1, $2, $3, $4)`

	getShardQry = `SELECT
 shard_id, range_id, data, data_encoding
 FROM shards WHERE shard_id = $1`

	updateShardQry = `UPDATE shards 
 SET range_id = $1, data = $2, data_encoding = $3 
 WHERE shard_id = $4`

	lockShardQry     = `SELECT range_id FROM shards WHERE shard_id = $1 FOR UPDATE`
	readLockShardQry = `SELECT range_id FROM shards WHERE shard_id = $1 FOR SHARE`
)

// InsertIntoShards inserts one or more rows into shards table
func (pdb *db) InsertIntoShards(
	ctx context.Context,
	row *sqlplugin.ShardsRow,
) (sql.Result, error) {
	return pdb.conn.ExecContext(ctx,
		createShardQry,
		row.ShardID,
		row.RangeID,
		row.Data,
		row.DataEncoding,
	)
}

// UpdateShards updates one or more rows into shards table
func (pdb *db) UpdateShards(
	ctx context.Context,
	row *sqlplugin.ShardsRow,
) (sql.Result, error) {
	return pdb.conn.ExecContext(ctx,
		updateShardQry,
		row.RangeID,
		row.Data,
		row.DataEncoding,
		row.ShardID,
	)
}

// SelectFromShards reads one or more rows from shards table
func (pdb *db) SelectFromShards(
	ctx context.Context,
	filter sqlplugin.ShardsFilter,
) (*sqlplugin.ShardsRow, error) {
	var row sqlplugin.ShardsRow
	err := pdb.conn.GetContext(ctx,
		&row,
		getShardQry,
		filter.ShardID,
	)
	if err != nil {
		return nil, err
	}
	return &row, nil
}

// ReadLockShards acquires a read lock on a single row in shards table
func (pdb *db) ReadLockShards(
	ctx context.Context,
	filter sqlplugin.ShardsFilter,
) (int64, error) {
	var rangeID int64
	err := pdb.conn.GetContext(ctx,
		&rangeID,
		readLockShardQry,
		filter.ShardID,
	)
	return rangeID, err
}

// WriteLockShards acquires a write lock on a single row in shards table
func (pdb *db) WriteLockShards(
	ctx context.Context,
	filter sqlplugin.ShardsFilter,
) (int64, error) {
	var rangeID int64
	err := pdb.conn.GetContext(ctx,
		&rangeID,
		lockShardQry,
		filter.ShardID,
	)
	return rangeID, err
}