Event ReaderWriter interface

Author: AndrewBurian

event.go

@@ -0,0 +1,82 @@
+package eventsource
+
+import (
+	"bytes"
+	"strconv"
+)
+
+// Holds the data for an event
+type Event struct {
+	id     []byte
+	data   [][]byte
+	event  []byte
+	retry  uint64
+	buf    bytes.Buffer
+	bufSet bool
+}
+
+// Read the event in wire format
+func (e *Event) Read(p []byte) (int, error) {
+	if e.bufSet {
+		return e.buf.Read(p)
+	}
+
+	// Wipe out any existing data
+	e.buf.Reset()
+
+	// event:
+	if len(e.event) > 0 {
+		e.buf.WriteString("event: ")
+		e.buf.Write(e.event)
+		e.buf.WriteByte('\n')
+	}
+
+	// id:
+	if len(e.id) > 0 {
+		e.buf.WriteString("id: ")
+		e.buf.Write(e.id)
+		e.buf.WriteByte('\n')
+	}
+
+	// data:
+	if len(e.data) > 0 {
+		for _, entry := range e.data {
+			e.buf.WriteString("data: ")
+			e.buf.Write(entry)
+			e.buf.WriteByte('\n')
+		}
+	}
+
+	// retry:
+	if e.retry > 0 {
+		e.buf.WriteString("retry: ")
+		e.buf.WriteString(strconv.FormatUint(e.retry, 10))
+		e.buf.WriteByte('\n')
+	}
+
+	e.buf.WriteByte('\n')
+	e.bufSet = true
+
+	return e.buf.Read(p)
+}
+
+// Write to the event. Buffer will be converted to one or more
+// `data` sections in wire format
+//
+// Successive calls to write will each create data entry lines
+//
+// Newlines will be split into multiple data entry lines, successive
+// newlines are discarded
+func (e *Event) Write(p []byte) (int, error) {
+	// split event on newlines
+	split := bytes.Split(p, []byte{'\n'})
+	for _, entry := range split {
+		// don't write empty entries
+		if len(entry) == 0 {
+			continue
+		}
+		e.data = append(e.data, entry)
+	}
+	e.bufSet = false
+	return len(p), nil
+}