d5dbe546e4
* Always defer *sql.Rows.Close and consult with Err database/sql.Rows.Next() makes sure to call Close only after exhausting result rows which would NOT happen when returning early from a bad Scan. Close being idempotent makes it a great candidate to get always deferred regardless of what happens later on the result set. This change also makes sure call Err() after exhausting Next() and propagate non-nil results from it as the documentation advises. Closes #764 Signed-off-by: Kiril Vladimiroff <kiril@vladimiroff.org> * Override named result parameters in last returns Signed-off-by: Kiril Vladimiroff <kiril@vladimiroff.org> * Do the same over new changes that got merged Signed-off-by: Kiril Vladimiroff <kiril@vladimiroff.org> Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
120 lines
3.4 KiB
Go
120 lines
3.4 KiB
Go
// Copyright 2018 New Vector Ltd
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package postgres
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import (
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"context"
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"database/sql"
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)
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const backwardExtremitiesSchema = `
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-- Stores output room events received from the roomserver.
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CREATE TABLE IF NOT EXISTS syncapi_backward_extremities (
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-- The 'room_id' key for the event.
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room_id TEXT NOT NULL,
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-- The event ID for the event.
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event_id TEXT NOT NULL,
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PRIMARY KEY(room_id, event_id)
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);
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`
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const insertBackwardExtremitySQL = "" +
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"INSERT INTO syncapi_backward_extremities (room_id, event_id)" +
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" VALUES ($1, $2)" +
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" ON CONFLICT DO NOTHING"
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const selectBackwardExtremitiesForRoomSQL = "" +
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"SELECT event_id FROM syncapi_backward_extremities WHERE room_id = $1"
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const isBackwardExtremitySQL = "" +
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"SELECT EXISTS (" +
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" SELECT TRUE FROM syncapi_backward_extremities" +
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" WHERE room_id = $1 AND event_id = $2" +
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")"
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const deleteBackwardExtremitySQL = "" +
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"DELETE FROM syncapi_backward_extremities WHERE room_id = $1 AND event_id = $2"
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type backwardExtremitiesStatements struct {
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insertBackwardExtremityStmt *sql.Stmt
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selectBackwardExtremitiesForRoomStmt *sql.Stmt
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isBackwardExtremityStmt *sql.Stmt
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deleteBackwardExtremityStmt *sql.Stmt
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}
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func (s *backwardExtremitiesStatements) prepare(db *sql.DB) (err error) {
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_, err = db.Exec(backwardExtremitiesSchema)
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if err != nil {
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return
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}
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if s.insertBackwardExtremityStmt, err = db.Prepare(insertBackwardExtremitySQL); err != nil {
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return
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}
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if s.selectBackwardExtremitiesForRoomStmt, err = db.Prepare(selectBackwardExtremitiesForRoomSQL); err != nil {
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return
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}
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if s.isBackwardExtremityStmt, err = db.Prepare(isBackwardExtremitySQL); err != nil {
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return
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}
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if s.deleteBackwardExtremityStmt, err = db.Prepare(deleteBackwardExtremitySQL); err != nil {
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return
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}
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return
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}
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func (s *backwardExtremitiesStatements) insertsBackwardExtremity(
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ctx context.Context, roomID, eventID string,
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) (err error) {
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_, err = s.insertBackwardExtremityStmt.ExecContext(ctx, roomID, eventID)
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return
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}
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func (s *backwardExtremitiesStatements) selectBackwardExtremitiesForRoom(
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ctx context.Context, roomID string,
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) (eventIDs []string, err error) {
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eventIDs = make([]string, 0)
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rows, err := s.selectBackwardExtremitiesForRoomStmt.QueryContext(ctx, roomID)
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if err != nil {
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return
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}
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defer rows.Close() // nolint: errcheck
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for rows.Next() {
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var eID string
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if err = rows.Scan(&eID); err != nil {
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return
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}
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eventIDs = append(eventIDs, eID)
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}
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return eventIDs, rows.Err()
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}
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func (s *backwardExtremitiesStatements) isBackwardExtremity(
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ctx context.Context, roomID, eventID string,
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) (isBE bool, err error) {
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err = s.isBackwardExtremityStmt.QueryRowContext(ctx, roomID, eventID).Scan(&isBE)
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return
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}
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func (s *backwardExtremitiesStatements) deleteBackwardExtremity(
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ctx context.Context, roomID, eventID string,
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) (err error) {
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_, err = s.insertBackwardExtremityStmt.ExecContext(ctx, roomID, eventID)
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return
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}
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