From: Daniel Theophanes Date: Sun, 24 Sep 2017 02:38:32 +0000 (-0700) Subject: database/sql: allow drivers to only implement Context variants X-Git-Tag: go1.10beta1~620 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=532714829ee4e816e54b6ccfe0b28f011f1659b2;p=gostls13.git database/sql: allow drivers to only implement Context variants Drivers shouldn't need to implement both Queryer and QueryerContext, they should just implement QueryerContext. Same with Execer and ExecerContext. This CL tests for QueryContext and ExecerContext first so drivers do not need to implement Queryer and Execer with an empty definition. Fixes #21663 Change-Id: Ifbaa71da669f4bc60f8da8c41a04a4afed699a9f Reviewed-on: https://go-review.googlesource.com/65733 Reviewed-by: Ian Lance Taylor --- diff --git a/src/database/sql/ctxutil.go b/src/database/sql/ctxutil.go index b73ee86594..170ec7d8a0 100644 --- a/src/database/sql/ctxutil.go +++ b/src/database/sql/ctxutil.go @@ -26,8 +26,8 @@ func ctxDriverPrepare(ctx context.Context, ci driver.Conn, query string) (driver return si, err } -func ctxDriverExec(ctx context.Context, execer driver.Execer, query string, nvdargs []driver.NamedValue) (driver.Result, error) { - if execerCtx, is := execer.(driver.ExecerContext); is { +func ctxDriverExec(ctx context.Context, execerCtx driver.ExecerContext, execer driver.Execer, query string, nvdargs []driver.NamedValue) (driver.Result, error) { + if execerCtx != nil { return execerCtx.ExecContext(ctx, query, nvdargs) } dargs, err := namedValueToValue(nvdargs) @@ -43,10 +43,9 @@ func ctxDriverExec(ctx context.Context, execer driver.Execer, query string, nvda return execer.Exec(query, dargs) } -func ctxDriverQuery(ctx context.Context, queryer driver.Queryer, query string, nvdargs []driver.NamedValue) (driver.Rows, error) { - if queryerCtx, is := queryer.(driver.QueryerContext); is { - ret, err := queryerCtx.QueryContext(ctx, query, nvdargs) - return ret, err +func ctxDriverQuery(ctx context.Context, queryerCtx driver.QueryerContext, queryer driver.Queryer, query string, nvdargs []driver.NamedValue) (driver.Rows, error) { + if queryerCtx != nil { + return queryerCtx.QueryContext(ctx, query, nvdargs) } dargs, err := namedValueToValue(nvdargs) if err != nil { diff --git a/src/database/sql/sql.go b/src/database/sql/sql.go index 49d352fbf5..7c35710688 100644 --- a/src/database/sql/sql.go +++ b/src/database/sql/sql.go @@ -1276,15 +1276,20 @@ func (db *DB) execDC(ctx context.Context, dc *driverConn, release func(error), q defer func() { release(err) }() - if execer, ok := dc.ci.(driver.Execer); ok { - var dargs []driver.NamedValue - dargs, err = driverArgs(dc.ci, nil, args) + execerCtx, ok := dc.ci.(driver.ExecerContext) + var execer driver.Execer + if !ok { + execer, ok = dc.ci.(driver.Execer) + } + if ok { + var nvdargs []driver.NamedValue + nvdargs, err = driverArgs(dc.ci, nil, args) if err != nil { return nil, err } var resi driver.Result withLock(dc, func() { - resi, err = ctxDriverExec(ctx, execer, query, dargs) + resi, err = ctxDriverExec(ctx, execerCtx, execer, query, nvdargs) }) if err != driver.ErrSkip { if err != nil { @@ -1343,15 +1348,20 @@ func (db *DB) query(ctx context.Context, query string, args []interface{}, strat // The ctx context is from a query method and the txctx context is from an // optional transaction context. func (db *DB) queryDC(ctx, txctx context.Context, dc *driverConn, releaseConn func(error), query string, args []interface{}) (*Rows, error) { - if queryer, ok := dc.ci.(driver.Queryer); ok { - dargs, err := driverArgs(dc.ci, nil, args) + queryerCtx, ok := dc.ci.(driver.QueryerContext) + var queryer driver.Queryer + if !ok { + queryer, ok = dc.ci.(driver.Queryer) + } + if ok { + nvdargs, err := driverArgs(dc.ci, nil, args) if err != nil { releaseConn(err) return nil, err } var rowsi driver.Rows withLock(dc, func() { - rowsi, err = ctxDriverQuery(ctx, queryer, query, dargs) + rowsi, err = ctxDriverQuery(ctx, queryerCtx, queryer, query, nvdargs) }) if err != driver.ErrSkip { if err != nil { diff --git a/src/database/sql/sql_test.go b/src/database/sql/sql_test.go index 046d95aff4..3551366369 100644 --- a/src/database/sql/sql_test.go +++ b/src/database/sql/sql_test.go @@ -3487,6 +3487,127 @@ func TestNamedValueCheckerSkip(t *testing.T) { } } +type ctxOnlyDriver struct { + fakeDriver +} + +func (d *ctxOnlyDriver) Open(dsn string) (driver.Conn, error) { + conn, err := d.fakeDriver.Open(dsn) + if err != nil { + return nil, err + } + return &ctxOnlyConn{fc: conn.(*fakeConn)}, nil +} + +var ( + _ driver.Conn = &ctxOnlyConn{} + _ driver.QueryerContext = &ctxOnlyConn{} + _ driver.ExecerContext = &ctxOnlyConn{} +) + +type ctxOnlyConn struct { + fc *fakeConn + + queryCtxCalled bool + execCtxCalled bool +} + +func (c *ctxOnlyConn) Begin() (driver.Tx, error) { + return c.fc.Begin() +} + +func (c *ctxOnlyConn) Close() error { + return c.fc.Close() +} + +// Prepare is still part of the Conn interface, so while it isn't used +// must be defined for compatibility. +func (c *ctxOnlyConn) Prepare(q string) (driver.Stmt, error) { + panic("not used") +} + +func (c *ctxOnlyConn) PrepareContext(ctx context.Context, q string) (driver.Stmt, error) { + return c.fc.PrepareContext(ctx, q) +} + +func (c *ctxOnlyConn) QueryContext(ctx context.Context, q string, args []driver.NamedValue) (driver.Rows, error) { + c.queryCtxCalled = true + return c.fc.QueryContext(ctx, q, args) +} + +func (c *ctxOnlyConn) ExecContext(ctx context.Context, q string, args []driver.NamedValue) (driver.Result, error) { + c.execCtxCalled = true + return c.fc.ExecContext(ctx, q, args) +} + +// TestQueryExecContextOnly ensures drivers only need to implement QueryContext +// and ExecContext methods. +func TestQueryExecContextOnly(t *testing.T) { + // Ensure connection does not implment non-context interfaces. + var connType driver.Conn = &ctxOnlyConn{} + if _, ok := connType.(driver.Execer); ok { + t.Fatalf("%T must not implement driver.Execer", connType) + } + if _, ok := connType.(driver.Queryer); ok { + t.Fatalf("%T must not implement driver.Queryer", connType) + } + + Register("ContextOnly", &ctxOnlyDriver{}) + db, err := Open("ContextOnly", "") + if err != nil { + t.Fatal(err) + } + defer db.Close() + + ctx, cancel := context.WithCancel(context.Background()) + defer cancel() + + conn, err := db.Conn(ctx) + if err != nil { + t.Fatal("db.Conn", err) + } + defer conn.Close() + + _, err = conn.ExecContext(ctx, "WIPE") + if err != nil { + t.Fatal("exec wipe", err) + } + + _, err = conn.ExecContext(ctx, "CREATE|keys|v1=string") + if err != nil { + t.Fatal("exec create", err) + } + expectedValue := "value1" + _, err = conn.ExecContext(ctx, "INSERT|keys|v1=?", expectedValue) + if err != nil { + t.Fatal("exec insert", err) + } + rows, err := conn.QueryContext(ctx, "SELECT|keys|v1|") + if err != nil { + t.Fatal("query select", err) + } + v1 := "" + for rows.Next() { + err = rows.Scan(&v1) + if err != nil { + t.Fatal("rows scan", err) + } + } + rows.Close() + + if v1 != expectedValue { + t.Fatalf("expected %q, got %q", expectedValue, v1) + } + + coc := conn.dc.ci.(*ctxOnlyConn) + if !coc.execCtxCalled { + t.Error("ExecContext not called") + } + if !coc.queryCtxCalled { + t.Error("QueryContext not called") + } +} + // badConn implements a bad driver.Conn, for TestBadDriver. // The Exec method panics. type badConn struct{}