Add CopyFrom to Tx and ConnPool

fixes #248

bench_test.go

@@ -485,27 +485,27 @@ const benchmarkWriteTableInsertSQL = `insert into t(
 	$13::bool
 )`
 
-type benchmarkWriteTableCopyToSrc struct {
+type benchmarkWriteTableCopyFromSrc struct {
 	count int
 	idx   int
 	row   []interface{}
 }
 
-func (s *benchmarkWriteTableCopyToSrc) Next() bool {
+func (s *benchmarkWriteTableCopyFromSrc) Next() bool {
 	s.idx++
 	return s.idx < s.count
 }
 
-func (s *benchmarkWriteTableCopyToSrc) Values() ([]interface{}, error) {
+func (s *benchmarkWriteTableCopyFromSrc) Values() ([]interface{}, error) {
 	return s.row, nil
 }
 
-func (s *benchmarkWriteTableCopyToSrc) Err() error {
+func (s *benchmarkWriteTableCopyFromSrc) Err() error {
 	return nil
 }
 
-func newBenchmarkWriteTableCopyToSrc(count int) pgx.CopyToSource {
-	return &benchmarkWriteTableCopyToSrc{
+func newBenchmarkWriteTableCopyFromSrc(count int) pgx.CopyFromSource {
+	return &benchmarkWriteTableCopyFromSrc{
 		count: count,
 		row: []interface{}{
 			"varchar_1",
@@ -538,7 +538,7 @@ func benchmarkWriteNRowsViaInsert(b *testing.B, n int) {
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
-		src := newBenchmarkWriteTableCopyToSrc(n)
+		src := newBenchmarkWriteTableCopyFromSrc(n)
 
 		tx, err := conn.Begin()
 		if err != nil {
@@ -561,7 +561,7 @@ func benchmarkWriteNRowsViaInsert(b *testing.B, n int) {
 
 // note this function is only used for benchmarks -- it doesn't escape tableName
 // or columnNames
-func multiInsert(conn *pgx.Conn, tableName string, columnNames []string, rowSrc pgx.CopyToSource) (int, error) {
+func multiInsert(conn *pgx.Conn, tableName string, columnNames []string, rowSrc pgx.CopyFromSource) (int, error) {
 	maxRowsPerInsert := 65535 / len(columnNames)
 	rowsThisInsert := 0
 	rowCount := 0
@@ -649,7 +649,7 @@ func benchmarkWriteNRowsViaMultiInsert(b *testing.B, n int) {
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
-		src := newBenchmarkWriteTableCopyToSrc(n)
+		src := newBenchmarkWriteTableCopyFromSrc(n)
 
 		_, err := multiInsert(conn, "t",
 			[]string{"varchar_1",
@@ -681,9 +681,9 @@ func benchmarkWriteNRowsViaCopy(b *testing.B, n int) {
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
-		src := newBenchmarkWriteTableCopyToSrc(n)
+		src := newBenchmarkWriteTableCopyFromSrc(n)
 
-		_, err := conn.CopyTo("t",
+		_, err := conn.CopyFrom(pgx.Identifier{"t"},
 			[]string{"varchar_1",
 				"varchar_2",
 				"varchar_null_1",

conn_pool.go

@@ -504,7 +504,8 @@ func (p *ConnPool) BeginIso(iso string) (*Tx, error) {
 	}
 }
 
-// CopyTo acquires a connection, delegates the call to that connection, and releases the connection
+// Deprecated. Use CopyFrom instead. CopyTo acquires a connection, delegates the
+// call to that connection, and releases the connection.
 func (p *ConnPool) CopyTo(tableName string, columnNames []string, rowSrc CopyToSource) (int, error) {
 	c, err := p.Acquire()
 	if err != nil {
@@ -514,3 +515,15 @@ func (p *ConnPool) CopyTo(tableName string, columnNames []string, rowSrc CopyToS
 
 	return c.CopyTo(tableName, columnNames, rowSrc)
 }
+
+// CopyFrom acquires a connection, delegates the call to that connection, and
+// releases the connection.
+func (p *ConnPool) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyToSource) (int, error) {
+	c, err := p.Acquire()
+	if err != nil {
+		return 0, err
+	}
+	defer p.Release(c)
+
+	return c.CopyFrom(tableName, columnNames, rowSrc)
+}

tx.go

@@ -158,7 +158,7 @@ func (tx *Tx) QueryRow(sql string, args ...interface{}) *Row {
 	return (*Row)(rows)
 }
 
-// CopyTo delegates to the underlying *Conn
+// Deprecated. Use CopyFrom instead. CopyTo delegates to the underlying *Conn
 func (tx *Tx) CopyTo(tableName string, columnNames []string, rowSrc CopyToSource) (int, error) {
 	if tx.status != TxStatusInProgress {
 		return 0, ErrTxClosed
@@ -167,6 +167,15 @@ func (tx *Tx) CopyTo(tableName string, columnNames []string, rowSrc CopyToSource
 	return tx.conn.CopyTo(tableName, columnNames, rowSrc)
 }
 
+// CopyFrom delegates to the underlying *Conn
+func (tx *Tx) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyToSource) (int, error) {
+	if tx.status != TxStatusInProgress {
+		return 0, ErrTxClosed
+	}
+
+	return tx.conn.CopyFrom(tableName, columnNames, rowSrc)
+}
+
 // Conn returns the *Conn this transaction is using.
 func (tx *Tx) Conn() *Conn {
 	return tx.conn