jobqueue: Introduce jobqueue backed by a postgres database

Co-authored-by: sanne <sanne.raymaekers@gmail.com>

vendor/github.com/jackc/pgproto3/v2/command_complete.go

@@ -0,0 +1,53 @@
+package pgproto3
+
+import (
+	"bytes"
+	"encoding/json"
+
+	"github.com/jackc/pgio"
+)
+
+type CommandComplete struct {
+	CommandTag []byte
+}
+
+// Backend identifies this message as sendable by the PostgreSQL backend.
+func (*CommandComplete) Backend() {}
+
+// Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
+// type identifier and 4 byte message length.
+func (dst *CommandComplete) Decode(src []byte) error {
+	idx := bytes.IndexByte(src, 0)
+	if idx != len(src)-1 {
+		return &invalidMessageFormatErr{messageType: "CommandComplete"}
+	}
+
+	dst.CommandTag = src[:idx]
+
+	return nil
+}
+
+// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
+func (src *CommandComplete) Encode(dst []byte) []byte {
+	dst = append(dst, 'C')
+	sp := len(dst)
+	dst = pgio.AppendInt32(dst, -1)
+
+	dst = append(dst, src.CommandTag...)
+	dst = append(dst, 0)
+
+	pgio.SetInt32(dst[sp:], int32(len(dst[sp:])))
+
+	return dst
+}
+
+// MarshalJSON implements encoding/json.Marshaler.
+func (src CommandComplete) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Type       string
+		CommandTag string
+	}{
+		Type:       "CommandComplete",
+		CommandTag: string(src.CommandTag),
+	})
+}