Pg to bun (#148)

* start moving to bun

* changing more stuff

* more

* and yet more

* tests passing

* seems stable now

* more big changes

* small fix

* little fixes

vendor/github.com/jackc/pgx/v4/tx.go

@@ -0,0 +1,444 @@
+package pgx
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"strconv"
+
+	"github.com/jackc/pgconn"
+)
+
+type TxIsoLevel string
+
+// Transaction isolation levels
+const (
+	Serializable    = TxIsoLevel("serializable")
+	RepeatableRead  = TxIsoLevel("repeatable read")
+	ReadCommitted   = TxIsoLevel("read committed")
+	ReadUncommitted = TxIsoLevel("read uncommitted")
+)
+
+type TxAccessMode string
+
+// Transaction access modes
+const (
+	ReadWrite = TxAccessMode("read write")
+	ReadOnly  = TxAccessMode("read only")
+)
+
+type TxDeferrableMode string
+
+// Transaction deferrable modes
+const (
+	Deferrable    = TxDeferrableMode("deferrable")
+	NotDeferrable = TxDeferrableMode("not deferrable")
+)
+
+type TxOptions struct {
+	IsoLevel       TxIsoLevel
+	AccessMode     TxAccessMode
+	DeferrableMode TxDeferrableMode
+}
+
+var emptyTxOptions TxOptions
+
+func (txOptions TxOptions) beginSQL() string {
+	if txOptions == emptyTxOptions {
+		return "begin"
+	}
+	buf := &bytes.Buffer{}
+	buf.WriteString("begin")
+	if txOptions.IsoLevel != "" {
+		fmt.Fprintf(buf, " isolation level %s", txOptions.IsoLevel)
+	}
+	if txOptions.AccessMode != "" {
+		fmt.Fprintf(buf, " %s", txOptions.AccessMode)
+	}
+	if txOptions.DeferrableMode != "" {
+		fmt.Fprintf(buf, " %s", txOptions.DeferrableMode)
+	}
+
+	return buf.String()
+}
+
+var ErrTxClosed = errors.New("tx is closed")
+
+// ErrTxCommitRollback occurs when an error has occurred in a transaction and
+// Commit() is called. PostgreSQL accepts COMMIT on aborted transactions, but
+// it is treated as ROLLBACK.
+var ErrTxCommitRollback = errors.New("commit unexpectedly resulted in rollback")
+
+// Begin starts a transaction. Unlike database/sql, the context only affects the begin command. i.e. there is no
+// auto-rollback on context cancellation.
+func (c *Conn) Begin(ctx context.Context) (Tx, error) {
+	return c.BeginTx(ctx, TxOptions{})
+}
+
+// BeginTx starts a transaction with txOptions determining the transaction mode. Unlike database/sql, the context only
+// affects the begin command. i.e. there is no auto-rollback on context cancellation.
+func (c *Conn) BeginTx(ctx context.Context, txOptions TxOptions) (Tx, error) {
+	_, err := c.Exec(ctx, txOptions.beginSQL())
+	if err != nil {
+		// begin should never fail unless there is an underlying connection issue or
+		// a context timeout. In either case, the connection is possibly broken.
+		c.die(errors.New("failed to begin transaction"))
+		return nil, err
+	}
+
+	return &dbTx{conn: c}, nil
+}
+
+// BeginFunc starts a transaction and calls f. If f does not return an error the transaction is committed. If f returns
+// an error the transaction is rolled back. The context will be used when executing the transaction control statements
+// (BEGIN, ROLLBACK, and COMMIT) but does not otherwise affect the execution of f.
+func (c *Conn) BeginFunc(ctx context.Context, f func(Tx) error) (err error) {
+	return c.BeginTxFunc(ctx, TxOptions{}, f)
+}
+
+// BeginTxFunc starts a transaction with txOptions determining the transaction mode and calls f. If f does not return
+// an error the transaction is committed. If f returns an error the transaction is rolled back. The context will be
+// used when executing the transaction control statements (BEGIN, ROLLBACK, and COMMIT) but does not otherwise affect
+// the execution of f.
+func (c *Conn) BeginTxFunc(ctx context.Context, txOptions TxOptions, f func(Tx) error) (err error) {
+	var tx Tx
+	tx, err = c.BeginTx(ctx, txOptions)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		rollbackErr := tx.Rollback(ctx)
+		if !(rollbackErr == nil || errors.Is(rollbackErr, ErrTxClosed)) {
+			err = rollbackErr
+		}
+	}()
+
+	fErr := f(tx)
+	if fErr != nil {
+		_ = tx.Rollback(ctx) // ignore rollback error as there is already an error to return
+		return fErr
+	}
+
+	return tx.Commit(ctx)
+}
+
+// Tx represents a database transaction.
+//
+// Tx is an interface instead of a struct to enable connection pools to be implemented without relying on internal pgx
+// state, to support pseudo-nested transactions with savepoints, and to allow tests to mock transactions. However,
+// adding a method to an interface is technically a breaking change. If new methods are added to Conn it may be
+// desirable to add them to Tx as well. Because of this the Tx interface is partially excluded from semantic version
+// requirements. Methods will not be removed or changed, but new methods may be added.
+type Tx interface {
+	// Begin starts a pseudo nested transaction.
+	Begin(ctx context.Context) (Tx, error)
+
+	// BeginFunc starts a pseudo nested transaction and executes f. If f does not return an err the pseudo nested
+	// transaction will be committed. If it does then it will be rolled back.
+	BeginFunc(ctx context.Context, f func(Tx) error) (err error)
+
+	// Commit commits the transaction if this is a real transaction or releases the savepoint if this is a pseudo nested
+	// transaction. Commit will return ErrTxClosed if the Tx is already closed, but is otherwise safe to call multiple
+	// times. If the commit fails with a rollback status (e.g. the transaction was already in a broken state) then
+	// ErrTxCommitRollback will be returned.
+	Commit(ctx context.Context) error
+
+	// Rollback rolls back the transaction if this is a real transaction or rolls back to the savepoint if this is a
+	// pseudo nested transaction. Rollback will return ErrTxClosed if the Tx is already closed, but is otherwise safe to
+	// call multiple times. Hence, a defer tx.Rollback() is safe even if tx.Commit() will be called first in a non-error
+	// condition. Any other failure of a real transaction will result in the connection being closed.
+	Rollback(ctx context.Context) error
+
+	CopyFrom(ctx context.Context, tableName Identifier, columnNames []string, rowSrc CopyFromSource) (int64, error)
+	SendBatch(ctx context.Context, b *Batch) BatchResults
+	LargeObjects() LargeObjects
+
+	Prepare(ctx context.Context, name, sql string) (*pgconn.StatementDescription, error)
+
+	Exec(ctx context.Context, sql string, arguments ...interface{}) (commandTag pgconn.CommandTag, err error)
+	Query(ctx context.Context, sql string, args ...interface{}) (Rows, error)
+	QueryRow(ctx context.Context, sql string, args ...interface{}) Row
+	QueryFunc(ctx context.Context, sql string, args []interface{}, scans []interface{}, f func(QueryFuncRow) error) (pgconn.CommandTag, error)
+
+	// Conn returns the underlying *Conn that on which this transaction is executing.
+	Conn() *Conn
+}
+
+// dbTx represents a database transaction.
+//
+// All dbTx methods return ErrTxClosed if Commit or Rollback has already been
+// called on the dbTx.
+type dbTx struct {
+	conn         *Conn
+	err          error
+	savepointNum int64
+	closed       bool
+}
+
+// Begin starts a pseudo nested transaction implemented with a savepoint.
+func (tx *dbTx) Begin(ctx context.Context) (Tx, error) {
+	if tx.closed {
+		return nil, ErrTxClosed
+	}
+
+	tx.savepointNum++
+	_, err := tx.conn.Exec(ctx, "savepoint sp_"+strconv.FormatInt(tx.savepointNum, 10))
+	if err != nil {
+		return nil, err
+	}
+
+	return &dbSavepoint{tx: tx, savepointNum: tx.savepointNum}, nil
+}
+
+func (tx *dbTx) BeginFunc(ctx context.Context, f func(Tx) error) (err error) {
+	if tx.closed {
+		return ErrTxClosed
+	}
+
+	var savepoint Tx
+	savepoint, err = tx.Begin(ctx)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		rollbackErr := savepoint.Rollback(ctx)
+		if !(rollbackErr == nil || errors.Is(rollbackErr, ErrTxClosed)) {
+			err = rollbackErr
+		}
+	}()
+
+	fErr := f(savepoint)
+	if fErr != nil {
+		_ = savepoint.Rollback(ctx) // ignore rollback error as there is already an error to return
+		return fErr
+	}
+
+	return savepoint.Commit(ctx)
+}
+
+// Commit commits the transaction.
+func (tx *dbTx) Commit(ctx context.Context) error {
+	if tx.closed {
+		return ErrTxClosed
+	}
+
+	commandTag, err := tx.conn.Exec(ctx, "commit")
+	tx.closed = true
+	if err != nil {
+		if tx.conn.PgConn().TxStatus() != 'I' {
+			_ = tx.conn.Close(ctx) // already have error to return
+		}
+		return err
+	}
+	if string(commandTag) == "ROLLBACK" {
+		return ErrTxCommitRollback
+	}
+
+	return nil
+}
+
+// Rollback rolls back the transaction. Rollback will return ErrTxClosed if the
+// Tx is already closed, but is otherwise safe to call multiple times. Hence, a
+// defer tx.Rollback() is safe even if tx.Commit() will be called first in a
+// non-error condition.
+func (tx *dbTx) Rollback(ctx context.Context) error {
+	if tx.closed {
+		return ErrTxClosed
+	}
+
+	_, err := tx.conn.Exec(ctx, "rollback")
+	tx.closed = true
+	if err != nil {
+		// A rollback failure leaves the connection in an undefined state
+		tx.conn.die(fmt.Errorf("rollback failed: %w", err))
+		return err
+	}
+
+	return nil
+}
+
+// Exec delegates to the underlying *Conn
+func (tx *dbTx) Exec(ctx context.Context, sql string, arguments ...interface{}) (commandTag pgconn.CommandTag, err error) {
+	return tx.conn.Exec(ctx, sql, arguments...)
+}
+
+// Prepare delegates to the underlying *Conn
+func (tx *dbTx) Prepare(ctx context.Context, name, sql string) (*pgconn.StatementDescription, error) {
+	if tx.closed {
+		return nil, ErrTxClosed
+	}
+
+	return tx.conn.Prepare(ctx, name, sql)
+}
+
+// Query delegates to the underlying *Conn
+func (tx *dbTx) Query(ctx context.Context, sql string, args ...interface{}) (Rows, error) {
+	if tx.closed {
+		// Because checking for errors can be deferred to the *Rows, build one with the error
+		err := ErrTxClosed
+		return &connRows{closed: true, err: err}, err
+	}
+
+	return tx.conn.Query(ctx, sql, args...)
+}
+
+// QueryRow delegates to the underlying *Conn
+func (tx *dbTx) QueryRow(ctx context.Context, sql string, args ...interface{}) Row {
+	rows, _ := tx.Query(ctx, sql, args...)
+	return (*connRow)(rows.(*connRows))
+}
+
+// QueryFunc delegates to the underlying *Conn.
+func (tx *dbTx) QueryFunc(ctx context.Context, sql string, args []interface{}, scans []interface{}, f func(QueryFuncRow) error) (pgconn.CommandTag, error) {
+	if tx.closed {
+		return nil, ErrTxClosed
+	}
+
+	return tx.conn.QueryFunc(ctx, sql, args, scans, f)
+}
+
+// CopyFrom delegates to the underlying *Conn
+func (tx *dbTx) CopyFrom(ctx context.Context, tableName Identifier, columnNames []string, rowSrc CopyFromSource) (int64, error) {
+	if tx.closed {
+		return 0, ErrTxClosed
+	}
+
+	return tx.conn.CopyFrom(ctx, tableName, columnNames, rowSrc)
+}
+
+// SendBatch delegates to the underlying *Conn
+func (tx *dbTx) SendBatch(ctx context.Context, b *Batch) BatchResults {
+	if tx.closed {
+		return &batchResults{err: ErrTxClosed}
+	}
+
+	return tx.conn.SendBatch(ctx, b)
+}
+
+// LargeObjects returns a LargeObjects instance for the transaction.
+func (tx *dbTx) LargeObjects() LargeObjects {
+	return LargeObjects{tx: tx}
+}
+
+func (tx *dbTx) Conn() *Conn {
+	return tx.conn
+}
+
+// dbSavepoint represents a nested transaction implemented by a savepoint.
+type dbSavepoint struct {
+	tx           Tx
+	savepointNum int64
+	closed       bool
+}
+
+// Begin starts a pseudo nested transaction implemented with a savepoint.
+func (sp *dbSavepoint) Begin(ctx context.Context) (Tx, error) {
+	if sp.closed {
+		return nil, ErrTxClosed
+	}
+
+	return sp.tx.Begin(ctx)
+}
+
+func (sp *dbSavepoint) BeginFunc(ctx context.Context, f func(Tx) error) (err error) {
+	if sp.closed {
+		return ErrTxClosed
+	}
+
+	return sp.tx.BeginFunc(ctx, f)
+}
+
+// Commit releases the savepoint essentially committing the pseudo nested transaction.
+func (sp *dbSavepoint) Commit(ctx context.Context) error {
+	if sp.closed {
+		return ErrTxClosed
+	}
+
+	_, err := sp.Exec(ctx, "release savepoint sp_"+strconv.FormatInt(sp.savepointNum, 10))
+	sp.closed = true
+	return err
+}
+
+// Rollback rolls back to the savepoint essentially rolling back the pseudo nested transaction. Rollback will return
+// ErrTxClosed if the dbSavepoint is already closed, but is otherwise safe to call multiple times. Hence, a defer sp.Rollback()
+// is safe even if sp.Commit() will be called first in a non-error condition.
+func (sp *dbSavepoint) Rollback(ctx context.Context) error {
+	if sp.closed {
+		return ErrTxClosed
+	}
+
+	_, err := sp.Exec(ctx, "rollback to savepoint sp_"+strconv.FormatInt(sp.savepointNum, 10))
+	sp.closed = true
+	return err
+}
+
+// Exec delegates to the underlying Tx
+func (sp *dbSavepoint) Exec(ctx context.Context, sql string, arguments ...interface{}) (commandTag pgconn.CommandTag, err error) {
+	if sp.closed {
+		return nil, ErrTxClosed
+	}
+
+	return sp.tx.Exec(ctx, sql, arguments...)
+}
+
+// Prepare delegates to the underlying Tx
+func (sp *dbSavepoint) Prepare(ctx context.Context, name, sql string) (*pgconn.StatementDescription, error) {
+	if sp.closed {
+		return nil, ErrTxClosed
+	}
+
+	return sp.tx.Prepare(ctx, name, sql)
+}
+
+// Query delegates to the underlying Tx
+func (sp *dbSavepoint) Query(ctx context.Context, sql string, args ...interface{}) (Rows, error) {
+	if sp.closed {
+		// Because checking for errors can be deferred to the *Rows, build one with the error
+		err := ErrTxClosed
+		return &connRows{closed: true, err: err}, err
+	}
+
+	return sp.tx.Query(ctx, sql, args...)
+}
+
+// QueryRow delegates to the underlying Tx
+func (sp *dbSavepoint) QueryRow(ctx context.Context, sql string, args ...interface{}) Row {
+	rows, _ := sp.Query(ctx, sql, args...)
+	return (*connRow)(rows.(*connRows))
+}
+
+// QueryFunc delegates to the underlying Tx.
+func (sp *dbSavepoint) QueryFunc(ctx context.Context, sql string, args []interface{}, scans []interface{}, f func(QueryFuncRow) error) (pgconn.CommandTag, error) {
+	if sp.closed {
+		return nil, ErrTxClosed
+	}
+
+	return sp.tx.QueryFunc(ctx, sql, args, scans, f)
+}
+
+// CopyFrom delegates to the underlying *Conn
+func (sp *dbSavepoint) CopyFrom(ctx context.Context, tableName Identifier, columnNames []string, rowSrc CopyFromSource) (int64, error) {
+	if sp.closed {
+		return 0, ErrTxClosed
+	}
+
+	return sp.tx.CopyFrom(ctx, tableName, columnNames, rowSrc)
+}
+
+// SendBatch delegates to the underlying *Conn
+func (sp *dbSavepoint) SendBatch(ctx context.Context, b *Batch) BatchResults {
+	if sp.closed {
+		return &batchResults{err: ErrTxClosed}
+	}
+
+	return sp.tx.SendBatch(ctx, b)
+}
+
+func (sp *dbSavepoint) LargeObjects() LargeObjects {
+	return LargeObjects{tx: sp}
+}
+
+func (sp *dbSavepoint) Conn() *Conn {
+	return sp.tx.Conn()
+}