README
¶
boltstore
Package boltstore is a boltdb storage engine for the SCS session package.
This is a good option for local development, or a single-server deployment. Unlike memstore the data will survive server restarts.
Usage
Installation
Either:
$ go get github.com/alexedwards/scs/engine/boltstore
Or (recommended) use use gvt to vendor the engine/boltstore
and session
sub-packages:
$ gvt fetch github.com/alexedwards/scs/engine/boltstore
$ gvt fetch github.com/alexedwards/scs/session
Setup
package main
import (
"io"
"log"
"net/http"
"time"
"github.com/alexedwards/scs/engine/boltstore"
"github.com/alexedwards/scs/session"
"github.com/boltdb/bolt"
)
func main() {
// You provide a bolt.DB instance
db, err := bolt.Open("testing.db", 0600, nil)
if err != nil {
log.Fatal(err)
}
defer db.Close()
// Create a new boltstore instance with bolt.DB
// and a cleanup interval of 5 minutes.
engine := boltstore.New(db, 5*time.Minute)
sessionManager := session.Manage(engine)
http.HandleFunc("/put", putHandler)
http.HandleFunc("/get", getHandler)
http.ListenAndServe(":4000", sessionManager(http.DefaultServeMux))
}
func putHandler(w http.ResponseWriter, r *http.Request) {
err := session.PutString(r, "message", "Hello world!")
if err != nil {
http.Error(w, err.Error(), 500)
}
}
func getHandler(w http.ResponseWriter, r *http.Request) {
msg, err := session.GetString(r, "message")
if err != nil {
http.Error(w, err.Error(), 500)
}
io.WriteString(w, msg)
}
Cleaning up expired session data
The boltstore package provides a background 'cleanup' goroutine to delete expired session data. This stops the database file from holding on to invalid sessions indefinitely and growing unnecessarily large.
You can specify how frequently to run the cleanup when creating a new boltstore instance:
// Run a cleanup every 30 minutes.
boltstore.New(db, 30*time.Minute)
// Setting the cleanup interval to zero prevents the cleanup from being run.
boltstore.New(db, 0)
Terminating the cleanup goroutine
It's rare that the cleanup goroutine for a boltstore instance needs to be terminated. It is generally intended to be long-lived and run for the lifetime of your application.
However, there may be occasions when your use of a boltstore instance is transient. A common example would be using it in a short-lived test function. In this scenario, the cleanup goroutine (which will run forever) will prevent the boltstore object from being garbage collected even after the test function has finished. You can prevent this by manually calling StopCleanup()
.
For example:
func TestExample(t *testing.T) {
db, err := bolt.Open("testing.db", 0600, nil)
if err != nil {
t.Fatal(err)
}
defer db.Close()
engine := New(db, time.Second)
defer engine.StopCleanup()
// Run test...
}
Notes
The boltstore package is underpinned by the excellent boltdb.
Full godoc documentation: https://godoc.org/github.com/alexedwards/scs/engine/boltstore.
Documentation
¶
Overview ¶
Package boltstore is a boltdb based storage engine for the SCS session package.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type BoltStore ¶
type BoltStore struct {
// contains filtered or unexported fields
}
BoltStore is a SCS storage engine backed by a boltdb file.
func New ¶
New creates a BoltStore instance.
The cleanupInterval parameter controls how frequently expired session data is removed by the background cleanup goroutine. Setting it to 0 prevents the cleanup goroutine from running (i.e. expired sessions will not be removed).
func (*BoltStore) Find ¶
Find returns the data for a session token. If the session token is not found or is expired, the exists flag will be false.
func (*BoltStore) Save ¶
Save updates data for a given session token with a given expiry. Any existing data + expiry will be over-written.
func (*BoltStore) StopCleanup ¶
func (bs *BoltStore) StopCleanup()
StopCleanup terminates the background cleanup goroutine for the BoltStore instance. It's rare to terminate this; generally BoltStore instances and their cleanup goroutines are intended to be long-lived and run for the lifetime of your application.
There may be occasions though when your use of the BoltStore is transient. An example is creating a new BoltStore instance in a test function. In this scenario, the cleanup goroutine (which will run forever) will prevent the BoltStore object from being garbage collected even after the test function has finished. You can prevent this by manually calling StopCleanup.
Example:
func TestExample(t *testing.T) { db, err := bolt.Open("testing.db", 0600, nil) if err != nil { t.Fatal(err) } defer db.Close() engine := boltstore.New(db, time.Second) defer engine.StopCleanup() // Run test... }