Initial commit

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

@@ -0,0 +1,209 @@
+package pgx
+
+import (
+	"context"
+	"errors"
+
+	"github.com/jackc/pgconn"
+)
+
+type batchItem struct {
+	query     string
+	arguments []interface{}
+}
+
+// Batch queries are a way of bundling multiple queries together to avoid
+// unnecessary network round trips.
+type Batch struct {
+	items []*batchItem
+}
+
+// Queue queues a query to batch b. query can be an SQL query or the name of a prepared statement.
+func (b *Batch) Queue(query string, arguments ...interface{}) {
+	b.items = append(b.items, &batchItem{
+		query:     query,
+		arguments: arguments,
+	})
+}
+
+// Len returns number of queries that have been queued so far.
+func (b *Batch) Len() int {
+	return len(b.items)
+}
+
+type BatchResults interface {
+	// Exec reads the results from the next query in the batch as if the query has been sent with Conn.Exec.
+	Exec() (pgconn.CommandTag, error)
+
+	// Query reads the results from the next query in the batch as if the query has been sent with Conn.Query.
+	Query() (Rows, error)
+
+	// QueryRow reads the results from the next query in the batch as if the query has been sent with Conn.QueryRow.
+	QueryRow() Row
+
+	// QueryFunc reads the results from the next query in the batch as if the query has been sent with Conn.QueryFunc.
+	QueryFunc(scans []interface{}, f func(QueryFuncRow) error) (pgconn.CommandTag, error)
+
+	// Close closes the batch operation. This must be called before the underlying connection can be used again. Any error
+	// that occurred during a batch operation may have made it impossible to resyncronize the connection with the server.
+	// In this case the underlying connection will have been closed.
+	Close() error
+}
+
+type batchResults struct {
+	ctx  context.Context
+	conn *Conn
+	mrr  *pgconn.MultiResultReader
+	err  error
+	b    *Batch
+	ix   int
+}
+
+// Exec reads the results from the next query in the batch as if the query has been sent with Exec.
+func (br *batchResults) Exec() (pgconn.CommandTag, error) {
+	if br.err != nil {
+		return nil, br.err
+	}
+
+	query, arguments, _ := br.nextQueryAndArgs()
+
+	if !br.mrr.NextResult() {
+		err := br.mrr.Close()
+		if err == nil {
+			err = errors.New("no result")
+		}
+		if br.conn.shouldLog(LogLevelError) {
+			br.conn.log(br.ctx, LogLevelError, "BatchResult.Exec", map[string]interface{}{
+				"sql":  query,
+				"args": logQueryArgs(arguments),
+				"err":  err,
+			})
+		}
+		return nil, err
+	}
+
+	commandTag, err := br.mrr.ResultReader().Close()
+
+	if err != nil {
+		if br.conn.shouldLog(LogLevelError) {
+			br.conn.log(br.ctx, LogLevelError, "BatchResult.Exec", map[string]interface{}{
+				"sql":  query,
+				"args": logQueryArgs(arguments),
+				"err":  err,
+			})
+		}
+	} else if br.conn.shouldLog(LogLevelInfo) {
+		br.conn.log(br.ctx, LogLevelInfo, "BatchResult.Exec", map[string]interface{}{
+			"sql":        query,
+			"args":       logQueryArgs(arguments),
+			"commandTag": commandTag,
+		})
+	}
+
+	return commandTag, err
+}
+
+// Query reads the results from the next query in the batch as if the query has been sent with Query.
+func (br *batchResults) Query() (Rows, error) {
+	query, arguments, ok := br.nextQueryAndArgs()
+	if !ok {
+		query = "batch query"
+	}
+
+	if br.err != nil {
+		return &connRows{err: br.err, closed: true}, br.err
+	}
+
+	rows := br.conn.getRows(br.ctx, query, arguments)
+
+	if !br.mrr.NextResult() {
+		rows.err = br.mrr.Close()
+		if rows.err == nil {
+			rows.err = errors.New("no result")
+		}
+		rows.closed = true
+
+		if br.conn.shouldLog(LogLevelError) {
+			br.conn.log(br.ctx, LogLevelError, "BatchResult.Query", map[string]interface{}{
+				"sql":  query,
+				"args": logQueryArgs(arguments),
+				"err":  rows.err,
+			})
+		}
+
+		return rows, rows.err
+	}
+
+	rows.resultReader = br.mrr.ResultReader()
+	return rows, nil
+}
+
+// QueryFunc reads the results from the next query in the batch as if the query has been sent with Conn.QueryFunc.
+func (br *batchResults) QueryFunc(scans []interface{}, f func(QueryFuncRow) error) (pgconn.CommandTag, error) {
+	rows, err := br.Query()
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		err = rows.Scan(scans...)
+		if err != nil {
+			return nil, err
+		}
+
+		err = f(rows)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return rows.CommandTag(), nil
+}
+
+// QueryRow reads the results from the next query in the batch as if the query has been sent with QueryRow.
+func (br *batchResults) QueryRow() Row {
+	rows, _ := br.Query()
+	return (*connRow)(rows.(*connRows))
+
+}
+
+// Close closes the batch operation. Any error that occurred during a batch operation may have made it impossible to
+// resyncronize the connection with the server. In this case the underlying connection will have been closed.
+func (br *batchResults) Close() error {
+	if br.err != nil {
+		return br.err
+	}
+
+	// log any queries that haven't yet been logged by Exec or Query
+	for {
+		query, args, ok := br.nextQueryAndArgs()
+		if !ok {
+			break
+		}
+
+		if br.conn.shouldLog(LogLevelInfo) {
+			br.conn.log(br.ctx, LogLevelInfo, "BatchResult.Close", map[string]interface{}{
+				"sql":  query,
+				"args": logQueryArgs(args),
+			})
+		}
+	}
+
+	return br.mrr.Close()
+}
+
+func (br *batchResults) nextQueryAndArgs() (query string, args []interface{}, ok bool) {
+	if br.b != nil && br.ix < len(br.b.items) {
+		bi := br.b.items[br.ix]
+		query = bi.query
+		args = bi.arguments
+		ok = true
+		br.ix++
+	}
+	return
+}