0c88a7b475
This code needs to work against cockroachDB, so transactions must be retried when a retryable error is returned. This change puts migrate transactions into the dbutil.WithTx transactional helpers to achieve this in the easiest way. Change-Id: Ib930e82d55cb0257357a222ce9131e6e53372c03
64 lines
1.5 KiB
Go
64 lines
1.5 KiB
Go
// Copyright (C) 2019 Storj Labs, Inc.
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// See LICENSE for copying information.
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package migrate
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import (
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"context"
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"database/sql"
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"github.com/zeebo/errs"
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)
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// Error is the default migrate errs class
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var Error = errs.Class("migrate")
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// Create with a previous schema check
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func Create(identifier string, db DBX) error {
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// is this necessary? it's not immediately obvious why we roll back the transaction
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// when the schemas match.
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justRollbackPlease := errs.Class("only used to tell WithTx to do a rollback")
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err := WithTx(context.Background(), db, func(ctx context.Context, tx *sql.Tx) (err error) {
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schema := db.Schema()
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_, err = tx.Exec(db.Rebind(`CREATE TABLE IF NOT EXISTS table_schemas (id text, schemaText text);`))
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if err != nil {
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return err
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}
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row := tx.QueryRow(db.Rebind(`SELECT schemaText FROM table_schemas WHERE id = ?;`), identifier)
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var previousSchema string
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err = row.Scan(&previousSchema)
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// not created yet
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if err == sql.ErrNoRows {
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_, err := tx.Exec(schema)
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if err != nil {
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return err
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}
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_, err = tx.Exec(db.Rebind(`INSERT INTO table_schemas(id, schemaText) VALUES (?, ?);`), identifier, schema)
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if err != nil {
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return err
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}
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return nil
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}
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if err != nil {
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return err
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}
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if schema != previousSchema {
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return Error.New("schema mismatch:\nold %v\nnew %v", previousSchema, schema)
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}
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return justRollbackPlease.New("")
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})
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if justRollbackPlease.Has(err) {
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err = nil
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}
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return Error.Wrap(err)
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}
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