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Package provides simple serialization for Go.
I use it for storing HTTP logs and other use cases.
The package consists of 2 layers:
  • serialization of records (multiple key / value pairs) into a blob of bytes
  • framing those bytes into self-delimited data packet with a timestamp and a type

Writing records to a file

A common use case is writing a sequence of records to a file.
Let's say we want to log information about HTTP requests. A single record has information about a single HTTP request (like URL, HTTP response code etc.).
This information is represented as key / value pairs (both strings).
func createWriter() (*siser.Writer, error) {
	f, err := os.Create("http_access.log")
	if err != nil {
		return nil, err
	w := siser.NewWriter(f)
	return w, nil

func logHTTPRequest(w *siser.Writer, url string, ipAddr string, statusCode int) error {
	var rec siser.Record
	// you can append multiple key/value pairs at once
	rec.Append("url", url, "ipaddr", ipAddr)
	// or assemble with multiple calls
	rec.Append("code", strconv.Itoa(statusCode))
	_, err := w.WriteRecord(&rec)
	return err
The data will be written to writer underlying siser.Writer as:
61 1553488435903 httplog
code: 200
What it means:
  • 61 is the size of the data. This allows us to read the exact number of bytes in the record
  • 1553488435903 is a timestamp which is Unix epoch time in milliseconds (more precision than standard Unix time which is in seconds)
  • httplog is optional name of the record. This allows us to easily write multiple types of records to the same file
To read back all records from the file:
f, err := os.Open("http_access.log")
defer f.Close()
reader := siser.NewReader(f)
for reader.ReadNextRecord() {
	rec := r.Record
	name := rec.Name // "httplog"
	timestamp := rec.Timestamp
	code, ok := rec.Get("code")
	// get rest of values and and do something with them

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