cloudfoundry-incubator/stratos

package sessiondata

import (
    "database/sql"
    "fmt"
    "strconv"
    "time"

    log "github.com/sirupsen/logrus"

    "github.com/cloudfoundry-incubator/stratos/src/jetstream/datastore"
    "github.com/cloudfoundry-incubator/stratos/src/jetstream/repository/interfaces"
)

var getSessionDataValues = `SELECT name, value FROM session_data WHERE expired=false AND session=$1 AND groupName = $1`

var insertSessionDataValue = `INSERT INTO session_data (session, groupName, name, value, keep_on_expire) VALUES ($1, $2, $3, $4, $5)`

var deleteSessionGroupData = `DELETE FROM session_data WHERE session=$1 AND groupName=$2`

// Expire data for sessions that no longer exist
var expireSessionData = `UPDATE session_data SET expired=true WHERE session NOT IN (SELECT id from sessions)`

// Delete data for sessions that no longer exist
var deleteSessionData = `DELETE FROM session_data WHERE expired=true AND keep_on_expire=false`

// Check if a session valid
var isValidSession = `SELECT id, expires_on from sessions WHERE id=$1`

// SessionDataRepository is a RDB-backed Session Data repository
type SessionDataRepository struct {
    db *sql.DB
}

// NewPostgresSessionDataRepository will create a new instance of the SessionDataRepository
func NewPostgresSessionDataRepository(dcp *sql.DB) (interfaces.SessionDataStore, error) {
    return &SessionDataRepository{db: dcp}, nil
}

// InitRepositoryProvider - One time init for the given DB Provider
func InitRepositoryProvider(databaseProvider string) {
    // Modify the database statements if needed, for the given database type
    getSessionDataValues = datastore.ModifySQLStatement(getSessionDataValues, databaseProvider)
    insertSessionDataValue = datastore.ModifySQLStatement(insertSessionDataValue, databaseProvider)
    deleteSessionGroupData = datastore.ModifySQLStatement(deleteSessionGroupData, databaseProvider)
    expireSessionData = datastore.ModifySQLStatement(expireSessionData, databaseProvider)
    deleteSessionData = datastore.ModifySQLStatement(deleteSessionData, databaseProvider)
    isValidSession = datastore.ModifySQLStatement(isValidSession, databaseProvider)
}

// GetValues returns all values from the config table as a map
func (c *SessionDataRepository) GetValues(session, group string) (map[string]string, error) {
    log.Debug("SessionDataRepository GetValues")
    rows, err := c.db.Query(getSessionDataValues, session, group)
    if err != nil {
        return nil, fmt.Errorf("Unable to retrieve session data records: %v", err)
    }
    defer rows.Close()

    var values = make(map[string]string)
    for rows.Next() {
        var (
            name  string
            value string
        )

        err := rows.Scan(&name, &value)
        if err != nil {
            return nil, fmt.Errorf("Unable to scan session data records: %v", err)
        }

        values[name] = value
    }

    if err = rows.Err(); err != nil {
        return nil, fmt.Errorf("Unable to get session data records: %v", err)
    }

    return values, nil
}

// DeleteValues deletes all values for the session and group
func (c *SessionDataRepository) DeleteValues(session, group string) error {
    log.Debug("SessionDataRepository DeleteValue")
    if _, err := c.db.Exec(deleteSessionGroupData, session, group); err != nil {
        return fmt.Errorf("Unable to delete session data values: %v", err)
    }

    return nil
}

// SetValues replaces existing group values with those provided
func (c *SessionDataRepository) SetValues(session, group string, values map[string]string, autoExpire bool) error {
    err := c.DeleteValues(session, group)
    if err != nil {
        return fmt.Errorf("SetValues: Unable to clear existing values: %v", err)
    }

    for key, value := range values {
        if _, err := c.db.Exec(insertSessionDataValue, session, group, key, value, autoExpire); err != nil {
            msg := "Unable to INSERT session data value: %v"
            log.Debugf(msg, err)
            return fmt.Errorf(msg, err)
        }
    }

    return nil
}

// IsValidSession - Determines if the given session ID is still valid (has not expired)
func (c *SessionDataRepository) IsValidSession(session int) (bool, error) {
    var (
        id     string
        expiry time.Time
    )

    err := c.db.QueryRow(isValidSession, strconv.Itoa(session)).Scan(&id, &expiry)

    switch {
    case err == sql.ErrNoRows:
        // No record with this ID - session does not exist
        return false, nil
    case err != nil:
        return false, fmt.Errorf("Error trying to find Session record: %v", err)
    default:
        // do nothing
    }

    // Check if the session has expired
    now := time.Now()
    return expiry.After(now), nil
}