initial commit

pgstore.go

@@ -0,0 +1,193 @@
+package pgstore
+
+import (
+	"database/sql"
+	"encoding/base32"
+	"github.com/coopernurse/gorp"
+	"github.com/gorilla/securecookie"
+	"github.com/gorilla/sessions"
+	_ "github.com/lib/pq"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type PGStore struct {
+	Codecs  []securecookie.Codec
+	Options *sessions.Options
+	path    string
+	DbMap   *gorp.DbMap
+}
+
+// Session type
+type Session struct {
+	Id         int64     `db: "id"`
+	Key        string    `db: "key"`
+	Data       string    `db: "data"`
+	CreatedOn  time.Time `db: "created_on"`
+	ModifiedOn time.Time `db: "modified_on"`
+	ExpiresOn  time.Time `db: "expires_on"`
+}
+
+func NewPGStore(dbUrl string, keyPairs ...[]byte) *PGStore {
+	db, err := sql.Open("postgres", dbUrl)
+	dbmap := &gorp.DbMap{Db: db, Dialect: gorp.PostgresDialect{}}
+
+	dbStore := &PGStore{
+		Codecs: securecookie.CodecsFromPairs(keyPairs...),
+		Options: &sessions.Options{
+			Path:   "/",
+			MaxAge: 86400 * 30,
+		},
+		DbMap: dbmap,
+	}
+
+	if err != nil {
+		// Ignore and return nil
+		//fmt.Printf("SQL connection error: %s\n", err)
+		return nil
+	}
+
+	// Create table if it doesn't exist
+	dbmap.AddTableWithName(Session{}, "http_sessions").SetKeys(true, "Id")
+	err = dbmap.CreateTablesIfNotExists()
+
+	if err != nil {
+		// Ignore and return nil
+		//fmt.Printf("Failed to create table http_sessions. Error: %s\n", err)
+		return nil
+	}
+
+	return dbStore
+}
+
+func (db *PGStore) Close() {
+	db.DbMap.Db.Close()
+}
+
+// Fetches a session for a given name after it has been added to the registry.
+func (db *PGStore) Get(r *http.Request, name string) (*sessions.Session, error) {
+	return sessions.GetRegistry(r).Get(db, name)
+}
+
+// New returns a new session for the given name w/o adding it to the registry.
+func (db *PGStore) New(r *http.Request, name string) (*sessions.Session, error) {
+	session := sessions.NewSession(db, name)
+	if session == nil {
+		return session, nil
+	}
+	session.Options = &(*db.Options)
+	session.IsNew = true
+
+	var err error
+	if c, errCookie := r.Cookie(name); errCookie == nil {
+		err = securecookie.DecodeMulti(name, c.Value, &session.ID, db.Codecs...)
+		if err == nil {
+			err = db.load(session)
+			if err == nil {
+				session.IsNew = false
+			}
+		}
+	}
+
+	return session, err
+}
+
+func (db *PGStore) Save(r *http.Request, w http.ResponseWriter, session *sessions.Session) error {
+	// Set delete if max-age is < 0
+	if session.Options.MaxAge < 0 {
+		if err := db.destroy(session); err != nil {
+			return err
+		}
+		http.SetCookie(w, sessions.NewCookie(session.Name(), "", session.Options))
+		return nil
+	}
+
+	if session.ID == "" {
+		// Generate a random session ID key suitable for storage in the DB
+		session.ID = string(securecookie.GenerateRandomKey(32))
+		session.ID = strings.TrimRight(
+			base32.StdEncoding.EncodeToString(
+				securecookie.GenerateRandomKey(32)), "=")
+	}
+
+	if err := db.save(session); err != nil {
+		return err
+	}
+
+	// Keep the session ID key in a cookie so it can be looked up in DB later.
+	encoded, err := securecookie.EncodeMulti(session.Name(), session.ID, db.Codecs...)
+	if err != nil {
+		return err
+	}
+
+	http.SetCookie(w, sessions.NewCookie(session.Name(), encoded, session.Options))
+	return nil
+}
+
+//load fetches a session by ID from the database and decodes its content into session.Values
+func (db *PGStore) load(session *sessions.Session) error {
+	var s Session
+	err := db.DbMap.SelectOne(&s, "SELECT * FROM http_sessions WHERE key = $1", session.ID)
+
+	if err := securecookie.DecodeMulti(session.Name(), string(s.Data),
+		&session.Values, db.Codecs...); err != nil {
+		return err
+	}
+
+	return err
+}
+
+// save writes encoded session.Values to a database record.
+// writes to http_sessions table by default.
+func (db *PGStore) save(session *sessions.Session) error {
+	encoded, err := securecookie.EncodeMulti(session.Name(), session.Values,
+		db.Codecs...)
+
+	if err != nil {
+		return err
+	}
+
+	var createdOn time.Time
+	var expiresOn time.Time
+
+	crOn := session.Values["created_on"]
+	exOn := session.Values["expires_on"]
+
+	if crOn == nil {
+		createdOn = time.Now()
+	} else {
+		createdOn = crOn.(time.Time)
+	}
+
+	if exOn == nil {
+		expiresOn = time.Now().Add(time.Second * time.Duration(session.Options.MaxAge))
+	} else {
+		expiresOn = exOn.(time.Time)
+		if expiresOn.Sub(time.Now().Add(time.Second*time.Duration(session.Options.MaxAge))) < 0 {
+			expiresOn = time.Now().Add(time.Second * time.Duration(session.Options.MaxAge))
+		}
+	}
+
+	s := Session{
+		Key:        session.ID,
+		Data:       encoded,
+		CreatedOn:  createdOn,
+		ExpiresOn:  expiresOn,
+		ModifiedOn: time.Now(),
+	}
+
+	if session.IsNew {
+		err = db.DbMap.Insert(&s)
+	} else {
+		_, err = db.DbMap.Update(&s)
+	}
+
+	return err
+}
+
+// Delete session
+func (db *PGStore) destroy(session *sessions.Session) error {
+	_, err := db.DbMap.Db.Exec("DELETE FROM http_sessions WHERE key = $1", session.ID)
+	return err
+}