csvutil/csvdriver: implement new database/sql/driver.XyzContext

Updates #720.

csvutil/csvdriver/driver.go

@@ -6,6 +6,7 @@
 package csvdriver // import "go-hep.org/x/hep/csvutil/csvdriver"
 
 import (
+	"context"
 	"database/sql"
 	"database/sql/driver"
 	"encoding/json"
@@ -21,13 +22,19 @@ import (
 )
 
 var (
-	_ driver.Driver  = (*csvDriver)(nil)
-	_ driver.Conn    = (*csvConn)(nil)
-	_ driver.Execer  = (*csvConn)(nil)
-	_ driver.Queryer = (*csvConn)(nil)
-	_ driver.Tx      = (*csvConn)(nil)
+	_ driver.Driver         = (*csvDriver)(nil)
+	_ drvConn               = (*csvConn)(nil)
+	_ driver.ExecerContext  = (*csvConn)(nil)
+	_ driver.QueryerContext = (*csvConn)(nil)
+	_ driver.Tx             = (*csvConn)(nil)
 )
 
+type drvConn interface {
+	driver.Conn
+	driver.ConnBeginTx
+	driver.ConnPrepareContext
+}
+
 // Conn describes how a connection to the CSV-driver should be established.
 type Conn struct {
 	File    string      `json:"file"`    // name of the file to be open
@@ -50,7 +57,6 @@ func (c *Conn) setDefaults() {
 	if c.Comment == 0 {
 		c.Comment = '#'
 	}
-	return
 }
 
 func (c Conn) toJSON() (string, error) {
@@ -194,9 +200,9 @@ type csvConn struct {
 	drv  *csvDriver
 	refs int
 
-	conn  driver.Conn
-	exec  driver.Execer
-	query driver.Queryer
+	conn  drvConn
+	exec  driver.ExecerContext
+	query driver.QueryerContext
 	tx    driver.Tx
 }
 
@@ -206,15 +212,42 @@ func (conn *csvConn) initDB() error {
 		return err
 	}
 
-	conn.conn = c
-	conn.exec = c.(driver.Execer)
-	conn.query = c.(driver.Queryer)
+	conn.conn = connWrap(c)
+	conn.exec = c.(driver.ExecerContext)
+	conn.query = c.(driver.QueryerContext)
 	return nil
 }
 
+func connWrap(c driver.Conn) drvConn {
+	if c, ok := c.(drvConn); ok {
+		return c
+	}
+
+	wrap := &drvConnWrap{
+		Conn:               c,
+		ConnPrepareContext: c.(driver.ConnPrepareContext),
+	}
+	return wrap
+}
+
+type drvConnWrap struct {
+	driver.Conn
+	driver.ConnPrepareContext
+}
+
+func (drv *drvConnWrap) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) {
+	// FIXME(sbinet): drop this hack when modernc.org/ql implements driver.ConnBeginTx.
+	return drv.Conn.Begin() //lint:ignore SA1019 drop this hack when modernc.org/ql supports driver.ConnBeginTx
+}
+
+// PrepareContext returns a prepared statement, bound to this connection.
+func (conn *csvConn) PrepareContext(ctx context.Context, query string) (driver.Stmt, error) {
+	return conn.conn.PrepareContext(ctx, query)
+}
+
 // Prepare returns a prepared statement, bound to this connection.
 func (conn *csvConn) Prepare(query string) (driver.Stmt, error) {
-	return conn.conn.Prepare(query)
+	return conn.conn.PrepareContext(context.Background(), query)
 }
 
 // Close invalidates and potentially stops any current
@@ -256,22 +289,27 @@ func (conn *csvConn) Close() error {
 	return err
 }
 
-// Begin starts and returns a new transaction.
-func (conn *csvConn) Begin() (driver.Tx, error) {
-	tx, err := conn.conn.Begin()
+// BeginTx starts and returns a new transaction.
+func (conn *csvConn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) {
+	tx, err := conn.conn.BeginTx(ctx, opts)
 	if err != nil {
 		return nil, err
 	}
 	conn.tx = tx
 	return tx, err
 }
 
-func (conn *csvConn) Exec(query string, args []driver.Value) (driver.Result, error) {
-	return conn.exec.Exec(query, args)
+// Begin starts and returns a new transaction.
+func (conn *csvConn) Begin() (driver.Tx, error) {
+	return conn.BeginTx(context.Background(), driver.TxOptions{})
+}
+
+func (conn *csvConn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
+	return conn.exec.ExecContext(ctx, query, args)
 }
 
-func (conn *csvConn) Query(query string, args []driver.Value) (driver.Rows, error) {
-	rows, err := conn.query.Query(query, args)
+func (conn *csvConn) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
+	rows, err := conn.query.QueryContext(ctx, query, args)
 	if err != nil {
 		return nil, err
 	}

csvutil/csvdriver/import.go

@@ -5,6 +5,7 @@
 package csvdriver
 
 import (
+	"context"
 	"database/sql/driver"
 	"fmt"
 	"io"
@@ -36,12 +37,14 @@ func (conn *csvConn) importCSV() error {
 	}
 	defer tx.Commit()
 
-	_, err = conn.Exec("create table csv ("+schema.Decl()+")", nil)
+	ctx := context.Background()
+
+	_, err = conn.ExecContext(ctx, "create table csv ("+schema.Decl()+")", nil)
 	if err != nil {
 		return err
 	}
 
-	_, err = conn.Exec("create index csv_id on csv (id());", nil)
+	_, err = conn.ExecContext(ctx, "create index csv_id on csv (id());", nil)
 	if err != nil {
 		return err
 	}
@@ -65,9 +68,9 @@ func (conn *csvConn) importCSV() error {
 			return err
 		}
 		for i, arg := range pargs {
-			vargs[i] = reflect.ValueOf(arg).Elem().Interface()
+			vargs[i].Value = reflect.ValueOf(arg).Elem().Interface()
 		}
-		_, err = conn.Exec(insert, vargs)
+		_, err = conn.ExecContext(ctx, insert, vargs)
 		if err != nil {
 			return err
 		}
@@ -177,12 +180,16 @@ func (st *schemaType) Decl() string {
 	return strings.Join(o, ", ")
 }
 
-func (st *schemaType) Args() ([]driver.Value, []interface{}) {
-	vargs := make([]driver.Value, len(*st))
+func (st *schemaType) Args() ([]driver.NamedValue, []interface{}) {
+	vargs := make([]driver.NamedValue, len(*st))
 	pargs := make([]interface{}, len(*st))
 	for i, v := range *st {
 		ptr := reflect.New(v.v.Type())
-		vargs[i] = ptr.Elem().Interface()
+		vargs[i] = driver.NamedValue{
+			Name:    v.n,
+			Ordinal: i + 1,
+			Value:   ptr.Elem().Interface(),
+		}
 		pargs[i] = ptr.Interface()
 	}
 	return vargs, pargs