SQLite cache

server/cache.go

@@ -1,61 +1,14 @@
 package server
 
 import (
-	"database/sql"
-	"time"
 	_ "github.com/mattn/go-sqlite3" // SQLite driver
+	"time"
 )
 
-const (
-	createTableQuery = `CREATE TABLE IF NOT EXISTS messages (
-		id VARCHAR(20) PRIMARY KEY,
-		time INT NOT NULL,
-		topic VARCHAR(64) NOT NULL,
-		message VARCHAR(1024) NOT NULL
-	)`
-	insertQuery         = `INSERT INTO messages (id, time, topic, message) VALUES (?, ?, ?, ?)`
-	pruneOlderThanQuery = `DELETE FROM messages WHERE time < ?`
-)
-
-type cache struct {
-	db *sql.DB
-	insert *sql.Stmt
-	prune *sql.Stmt
-}
-
-func newCache(filename string) (*cache, error) {
-	db, err := sql.Open("sqlite3", filename)
-	if err != nil {
-		return nil, err
-	}
-	if _, err := db.Exec(createTableQuery); err != nil {
-		return nil, err
-	}
-	insert, err := db.Prepare(insertQuery)
-	if err != nil {
-		return nil, err
-	}
-	prune, err := db.Prepare(pruneOlderThanQuery)
-	if err != nil {
-		return nil, err
-	}
-	return &cache{
-		db:     db,
-		insert: insert,
-		prune:  prune,
-	}, nil
-}
-
-func (c *cache) Load() (map[string]*topic, error) {
-
-}
-
-func (c *cache) Add(m *message) error {
-	_, err := c.insert.Exec(m.ID, m.Time, m.Topic, m.Message)
-	return err
-}
-
-func (c *cache) Prune(olderThan time.Duration) error {
-	_, err := c.prune.Exec(time.Now().Add(-1 * olderThan).Unix())
-	return err
+type cache interface {
+	AddMessage(m *message) error
+	Messages(topic string, since time.Time) ([]*message, error)
+	MessageCount(topic string) (int, error)
+	Topics() (map[string]*topic, error)
+	Prune(keep time.Duration) error
 }