Replace lastStmtSent with pgconn support

conn.go

@@ -45,8 +45,6 @@ type Conn struct {
 
 	causeOfDeath error
 
-	lastStmtSent bool
-
 	doneChan   chan struct{}
 	closedChan chan error
 
@@ -392,17 +390,6 @@ func connInfoFromRows(rows Rows, err error) (map[string]pgtype.OID, error) {
 	return nameOIDs, err
 }
 
-// LastStmtSent returns true if the last call to Query(Ex)/Exec(Ex) attempted to
-// send the statement over the wire. Each call to a Query(Ex)/Exec(Ex) resets
-// the value to false initially until the statement has been sent. This does
-// NOT mean that the statement was successful or even received, it just means
-// that a write was attempted and therefore it could have been executed. Calls
-// to prepare a statement are ignored, only when the prepared statement is
-// attempted to be executed will this return true.
-func (c *Conn) LastStmtSent() bool {
-	return c.lastStmtSent
-}
-
 // PgConn returns the underlying *pgconn.PgConn. This is an escape hatch method that allows lower level access to the
 // PostgreSQL connection than pgx exposes.
 //
@@ -413,8 +400,6 @@ func (c *Conn) PgConn() *pgconn.PgConn { return c.pgConn }
 // Exec executes sql. sql can be either a prepared statement name or an SQL string. arguments should be referenced
 // positionally from the sql string as $1, $2, etc.
 func (c *Conn) Exec(ctx context.Context, sql string, arguments ...interface{}) (pgconn.CommandTag, error) {
-	c.lastStmtSent = false
-
 	startTime := time.Now()
 
 	commandTag, err := c.exec(ctx, sql, arguments...)
@@ -462,13 +447,11 @@ func (c *Conn) exec(ctx context.Context, sql string, arguments ...interface{}) (
 			}
 		}
 
-		c.lastStmtSent = true
 		result := c.pgConn.ExecPrepared(ctx, ps.Name, paramValues, paramFormats, resultFormats).Read()
 		return result.CommandTag, result.Err
 	}
 
 	if len(arguments) == 0 {
-		c.lastStmtSent = true
 		results, err := c.pgConn.Exec(ctx, sql).ReadAll()
 		if err != nil {
 			return nil, err
@@ -529,7 +512,6 @@ func (c *Conn) exec(ctx context.Context, sql string, arguments ...interface{}) (
 			}
 		}
 
-		c.lastStmtSent = true
 		result := c.pgConn.ExecPrepared(ctx, psd.Name, paramValues, paramFormats, resultFormats).Read()
 		return result.CommandTag, result.Err
 	}

conn_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/jackc/pgx"
 	"github.com/jackc/pgx/pgtype"
 	"github.com/stretchr/testify/require"
+	errors "golang.org/x/xerrors"
 )
 
 func TestCrateDBConnect(t *testing.T) {
@@ -122,18 +123,12 @@ func TestExecFailure(t *testing.T) {
 	if _, err := conn.Exec(context.Background(), "selct;"); err == nil {
 		t.Fatal("Expected SQL syntax error")
 	}
-	if !conn.LastStmtSent() {
-		t.Error("Expected LastStmtSent to return true")
-	}
 
 	rows, _ := conn.Query(context.Background(), "select 1")
 	rows.Close()
 	if rows.Err() != nil {
 		t.Fatalf("Exec failure appears to have broken connection: %v", rows.Err())
 	}
-	if !conn.LastStmtSent() {
-		t.Error("Expected LastStmtSent to return true")
-	}
 }
 
 func TestExecFailureWithArguments(t *testing.T) {
@@ -142,11 +137,12 @@ func TestExecFailureWithArguments(t *testing.T) {
 	conn := mustConnectString(t, os.Getenv("PGX_TEST_DATABASE"))
 	defer closeConn(t, conn)
 
-	if _, err := conn.Exec(context.Background(), "selct $1;", 1); err == nil {
+	_, err := conn.Exec(context.Background(), "selct $1;", 1)
+	if err == nil {
 		t.Fatal("Expected SQL syntax error")
 	}
-	if conn.LastStmtSent() {
+	if errors.Is(err, pgconn.ErrNoBytesSent) {
-		t.Error("Expected LastStmtSent to return false")
+		t.Error("Expected bytes to be sent to server")
 	}
 }
 
@@ -164,10 +160,10 @@ func TestExecContextWithoutCancelation(t *testing.T) {
 		t.Fatal(err)
 	}
 	if string(commandTag) != "CREATE TABLE" {
-		t.Fatalf("Unexpected results from ExecEx: %v", commandTag)
+		t.Fatalf("Unexpected results from Exec: %v", commandTag)
 	}
-	if !conn.LastStmtSent() {
+	if errors.Is(err, pgconn.ErrNoBytesSent) {
-		t.Error("Expected LastStmtSent to return true")
+		t.Error("Expected bytes to be sent to server")
 	}
 }
 
@@ -180,11 +176,12 @@ func TestExecContextFailureWithoutCancelation(t *testing.T) {
 	ctx, cancelFunc := context.WithCancel(context.Background())
 	defer cancelFunc()
 
-	if _, err := conn.Exec(ctx, "selct;"); err == nil {
+	_, err := conn.Exec(ctx, "selct;")
+	if err == nil {
 		t.Fatal("Expected SQL syntax error")
 	}
-	if !conn.LastStmtSent() {
+	if errors.Is(err, pgconn.ErrNoBytesSent) {
-		t.Error("Expected LastStmtSent to return true")
+		t.Error("Expected bytes to be sent to server")
 	}
 
 	rows, _ := conn.Query(context.Background(), "select 1")
@@ -192,8 +189,8 @@ func TestExecContextFailureWithoutCancelation(t *testing.T) {
 	if rows.Err() != nil {
 		t.Fatalf("ExecEx failure appears to have broken connection: %v", rows.Err())
 	}
-	if !conn.LastStmtSent() {
+	if errors.Is(err, pgconn.ErrNoBytesSent) {
-		t.Error("Expected LastStmtSent to return true")
+		t.Error("Expected bytes to be sent to server")
 	}
 }
 
@@ -206,26 +203,27 @@ func TestExecContextFailureWithoutCancelationWithArguments(t *testing.T) {
 	ctx, cancelFunc := context.WithCancel(context.Background())
 	defer cancelFunc()
 
-	if _, err := conn.Exec(ctx, "selct $1;", 1); err == nil {
+	_, err := conn.Exec(ctx, "selct $1;", 1)
+	if err == nil {
 		t.Fatal("Expected SQL syntax error")
 	}
-	if conn.LastStmtSent() {
+	if errors.Is(err, pgconn.ErrNoBytesSent) {
-		t.Error("Expected LastStmtSent to return false")
+		t.Error("Expected bytes to be sent to server")
 	}
 }
 
 func TestExecFailureCloseBefore(t *testing.T) {
-	t.Skip("TODO: LastStmtSent needs to be ported / rewritten for pgconn")
 	t.Parallel()
 
 	conn := mustConnectString(t, os.Getenv("PGX_TEST_DATABASE"))
 	closeConn(t, conn)
 
-	if _, err := conn.Exec(context.Background(), "select 1"); err == nil {
+	_, err := conn.Exec(context.Background(), "select 1")
+	if err == nil {
 		t.Fatal("Expected network error")
 	}
-	if conn.LastStmtSent() {
+	if !errors.Is(err, pgconn.ErrNoBytesSent) {
-		t.Error("Expected LastStmtSent to return false")
+		t.Error("Expected no bytes to be sent to server")
 	}
 }
 
@@ -261,20 +259,6 @@ func TestExecExtendedProtocol(t *testing.T) {
 	ensureConnValid(t, conn)
 }
 
-func TestExecExFailureCloseBefore(t *testing.T) {
-	t.Parallel()
-
-	conn := mustConnectString(t, os.Getenv("PGX_TEST_DATABASE"))
-	closeConn(t, conn)
-
-	if _, err := conn.Exec(context.Background(), "select 1", nil); err == nil {
-		t.Fatal("Expected network error")
-	}
-	if conn.LastStmtSent() {
-		t.Error("Expected LastStmtSent to return false")
-	}
-}
-
 func TestPrepare(t *testing.T) {
 	t.Parallel()
 
@@ -478,7 +462,7 @@ func TestCatchSimultaneousConnectionQueries(t *testing.T) {
 	defer rows1.Close()
 
 	_, err = conn.Query(context.Background(), "select generate_series(1,$1)", 10)
-	if err != pgconn.ErrConnBusy {
+	if !errors.Is(err, pgconn.ErrConnBusy) {
 		t.Fatalf("conn.Query should have failed with pgconn.ErrConnBusy, but it was %v", err)
 	}
 }
@@ -496,7 +480,7 @@ func TestCatchSimultaneousConnectionQueryAndExec(t *testing.T) {
 	defer rows.Close()
 
 	_, err = conn.Exec(context.Background(), "create temporary table foo(spice timestamp[])")
-	if err != pgconn.ErrConnBusy {
+	if !errors.Is(err, pgconn.ErrConnBusy) {
 		t.Fatalf("conn.Exec should have failed with pgconn.ErrConnBusy, but it was %v", err)
 	}
 }

go.mod

@@ -4,10 +4,10 @@ go 1.12
 
 require (
 	github.com/cockroachdb/apd v1.1.0
-	github.com/jackc/pgconn v0.0.0-20190420161109-39e6ff5766bd
+	github.com/jackc/pgconn v0.0.0-20190420214824-7e0022ef6ba3
 	github.com/jackc/pgio v1.0.0
 	github.com/jackc/pgproto3 v1.1.0
-	github.com/jackc/pgproto3/v2 v2.0.0-alpha1.0.20190419041544-9b6a681f50bf
+	github.com/jackc/pgproto3/v2 v2.0.0-alpha1.0.20190420180111-c116219b62db
 	github.com/jackc/puddle v0.0.0-20190413234325-e4ced69a3a2b
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/lib/pq v1.0.0
@@ -20,5 +20,6 @@ require (
 	go.uber.org/atomic v1.3.2 // indirect
 	go.uber.org/multierr v1.1.0 // indirect
 	go.uber.org/zap v1.9.1
+	golang.org/x/xerrors v0.0.0-20190410155217-1f06c39b4373
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 )

go.sum

@@ -16,6 +16,8 @@ github.com/jackc/pgconn v0.0.0-20190419211655-3710e52a9a12 h1:PzGjcOqGl6npHTDt8y
 github.com/jackc/pgconn v0.0.0-20190419211655-3710e52a9a12/go.mod h1:UsnoyBN75lNxOeZXUT70J9xAvZffv2fxrxCrIPIH/Rk=
 github.com/jackc/pgconn v0.0.0-20190420161109-39e6ff5766bd h1:eSKDWtHcm6H/vELPrs6fh7bch3wBc2vUvqVnHw17+5c=
 github.com/jackc/pgconn v0.0.0-20190420161109-39e6ff5766bd/go.mod h1:UsnoyBN75lNxOeZXUT70J9xAvZffv2fxrxCrIPIH/Rk=
+github.com/jackc/pgconn v0.0.0-20190420214824-7e0022ef6ba3 h1:ZFYpB74Kq8xE9gmfxCmXD6QxZ27ja+j3HwGFc+YurhQ=
+github.com/jackc/pgconn v0.0.0-20190420214824-7e0022ef6ba3/go.mod h1:jkELnwuX+w9qN5YIfX0fl88Ehu4XC3keFuOJJk9pcnA=
 github.com/jackc/pgio v1.0.0 h1:g12B9UwVnzGhueNavwioyEEpAmqMe1E/BN9ES+8ovkE=
 github.com/jackc/pgio v1.0.0/go.mod h1:oP+2QK2wFfUWgr+gxjoBH9KGBb31Eio69xUb0w5bYf8=
 github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
@@ -26,6 +28,8 @@ github.com/jackc/pgproto3 v1.1.0 h1:FYYE4yRw+AgI8wXIinMlNjBbp/UitDJwfj5LqqewP1A=
 github.com/jackc/pgproto3 v1.1.0/go.mod h1:eR5FA3leWg7p9aeAqi37XOTgTIbkABlvcPB3E5rlc78=
 github.com/jackc/pgproto3/v2 v2.0.0-alpha1.0.20190419041544-9b6a681f50bf h1:wI8d/uq9/RfZOe6bKOpC4Skd4VgkTIGZqxmHu6IQGb8=
 github.com/jackc/pgproto3/v2 v2.0.0-alpha1.0.20190419041544-9b6a681f50bf/go.mod h1:bhq50y+xrl9n5mRYyCBFKkpRVTLYJVWeCc+mEAI3yXA=
+github.com/jackc/pgproto3/v2 v2.0.0-alpha1.0.20190420180111-c116219b62db h1:UpaKn/gYxzH6/zWyRQH1S260zvKqwJJ4h8+Kf09ooh0=
+github.com/jackc/pgproto3/v2 v2.0.0-alpha1.0.20190420180111-c116219b62db/go.mod h1:bhq50y+xrl9n5mRYyCBFKkpRVTLYJVWeCc+mEAI3yXA=
 github.com/jackc/puddle v0.0.0-20190413234325-e4ced69a3a2b h1:cIcUpcEP55F/QuZWEtXyqHoWk+IV4TBiLjtBkeq/Q1c=
 github.com/jackc/puddle v0.0.0-20190413234325-e4ced69a3a2b/go.mod h1:m4B5Dj62Y0fbyuIc15OsIqK0+JU8nkqQjsgx7dvjSWk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
@@ -70,5 +74,7 @@ golang.org/x/sys v0.0.0-20190403152447-81d4e9dc473e h1:nFYrTHrdrAOpShe27kaFHjsqY
 golang.org/x/sys v0.0.0-20190403152447-81d4e9dc473e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/xerrors v0.0.0-20190410155217-1f06c39b4373 h1:PPwnA7z1Pjf7XYaBP9GL1VAMZmcIWyFz7QCMSIIa3Bg=
+golang.org/x/xerrors v0.0.0-20190410155217-1f06c39b4373/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

query.go

@@ -286,7 +286,6 @@ type QueryResultFormats []int16
 // Query executes sql with args. If there is an error the returned Rows will be returned in an error state. So it is
 // allowed to ignore the error returned from Query and handle it in Rows.
 func (c *Conn) Query(ctx context.Context, sql string, args ...interface{}) (Rows, error) {
-	c.lastStmtSent = false
 	// rows = c.getRows(sql, args)
 
 	var resultFormats QueryResultFormats
@@ -369,7 +368,6 @@ optionLoop:
 		}
 	}
 
-	c.lastStmtSent = true
 	rows.resultReader = c.pgConn.ExecPrepared(ctx, ps.Name, paramValues, paramFormats, resultFormats)
 
 	return rows, rows.err

query_test.go

@@ -18,6 +18,7 @@ import (
 	satori "github.com/jackc/pgx/pgtype/ext/satori-uuid"
 	uuid "github.com/satori/go.uuid"
 	"github.com/shopspring/decimal"
+	errors "golang.org/x/xerrors"
 )
 
 func TestConnQueryScan(t *testing.T) {
@@ -285,8 +286,8 @@ func TestConnQueryCloseEarlyWithErrorOnWire(t *testing.T) {
 	if err != nil {
 		t.Fatalf("conn.Query failed: %v", err)
 	}
-	if !conn.LastStmtSent() {
+	if errors.Is(err, pgconn.ErrNoBytesSent) {
-		t.Error("Expected LastStmtSent to return true")
+		t.Error("Expected bytes to be sent to server")
 	}
 	rows.Close()
 
@@ -436,8 +437,8 @@ func TestQueryEncodeError(t *testing.T) {
 	if err != nil {
 		t.Errorf("conn.Query failure: %v", err)
 	}
-	if !conn.LastStmtSent() {
+	if errors.Is(err, pgconn.ErrNoBytesSent) {
-		t.Error("Expected LastStmtSent to return true")
+		t.Error("Expected bytes to be sent to server")
 	}
 	defer rows.Close()
 
@@ -1158,9 +1159,6 @@ func TestQueryContextSuccess(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if !conn.LastStmtSent() {
-		t.Error("Expected LastStmtSent to return true")
-	}
 
 	var result, rowCount int
 	for rows.Next() {
@@ -1239,9 +1237,6 @@ func TestQueryRowContextSuccess(t *testing.T) {
 	if result != 42 {
 		t.Fatalf("Expected result 42, got %d", result)
 	}
-	if !conn.LastStmtSent() {
-		t.Error("Expected LastStmtSent to return true")
-	}
 
 	ensureConnValid(t, conn)
 }
@@ -1270,10 +1265,11 @@ func TestQueryCloseBefore(t *testing.T) {
 	conn := mustConnectString(t, os.Getenv("PGX_TEST_DATABASE"))
 	closeConn(t, conn)
 
-	if _, err := conn.Query(context.Background(), "select 1"); err == nil {
+	_, err := conn.Query(context.Background(), "select 1")
+	if err == nil {
 		t.Fatal("Expected network error")
 	}
-	if conn.LastStmtSent() {
+	if !errors.Is(err, pgconn.ErrNoBytesSent) {
-		t.Error("Expected LastStmtSent to return false")
+		t.Error("Expected bytes to be sent to server")
 	}
 }

stdlib/sql.go

@@ -80,8 +80,9 @@ import (
 	"sync"
 	"time"
 
-	"github.com/pkg/errors"
+	errors "golang.org/x/xerrors"
 
+	"github.com/jackc/pgconn"
 	"github.com/jackc/pgx"
 	"github.com/jackc/pgx/pgtype"
 )
@@ -226,8 +227,9 @@ func (c *Conn) ExecContext(ctx context.Context, query string, argsV []driver.Nam
 
 	commandTag, err := c.conn.Exec(ctx, query, args...)
 	// if we got a network error before we had a chance to send the query, retry
-	if err != nil && !c.conn.LastStmtSent() {
+	if err != nil {
-		if _, is := err.(net.Error); is {
+		var netErr net.Error
+		if is := errors.As(err, &netErr); is && errors.Is(err, pgconn.ErrNoBytesSent) {
 			return nil, driver.ErrBadConn
 		}
 	}