initial architecture overhaul

cache/cache.go

@@ -0,0 +1,84 @@
+// Copyright 2013 The Chihaya Authors. All rights reserved.
+// Use of this source code is governed by the BSD 2-Clause license,
+// which can be found in the LICENSE file.
+
+// Package storage provides a generic interface for manipulating a
+// BitTorrent tracker's cache.
+package cache
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/pushrax/chihaya/config"
+	"github.com/pushrax/chihaya/models"
+)
+
+var (
+	drivers   = make(map[string]Driver)
+	ErrTxDone = errors.New("storage: Transaction has already been committed or rolled back")
+)
+
+type Driver interface {
+	New(*config.Cache) Pool
+}
+
+// Register makes a database driver available by the provided name.
+// If Register is called twice with the same name or if driver is nil,
+// it panics.
+func Register(name string, driver Driver) {
+	if driver == nil {
+		panic("storage: Register driver is nil")
+	}
+	if _, dup := drivers[name]; dup {
+		panic("storage: Register called twice for driver " + name)
+	}
+	drivers[name] = driver
+}
+
+// Open creates a pool of data store connections specified by a storage configuration.
+func Open(conf *config.Cache) (Pool, error) {
+	driver, ok := drivers[conf.Driver]
+	if !ok {
+		return nil, fmt.Errorf(
+			"storage: unknown driver %q (forgotten import?)",
+			conf.Driver,
+		)
+	}
+	pool := driver.New(conf)
+	return pool, nil
+}
+
+// Pool represents a thread-safe pool of connections to the data store
+// that can be used to obtain transactions.
+type Pool interface {
+	Close() error
+	Get() (Tx, error)
+}
+
+// Tx represents an in-progress data store transaction.
+// A transaction must end with a call to Commit or Rollback.
+//
+// After a call to Commit or Rollback, all operations on the
+// transaction must fail with ErrTxDone.
+type Tx interface {
+	Commit() error
+	Rollback() error
+
+	// Reads
+	FindUser(passkey string) (*models.User, bool, error)
+	FindTorrent(infohash string) (*models.Torrent, bool, error)
+	ClientWhitelisted(peerID string) (bool, error)
+
+	// Writes
+	RecordSnatch(u *models.User, t *models.Torrent) error
+	MarkActive(t *models.Torrent) error
+	AddLeecher(t *models.Torrent, p *models.Peer) error
+	AddSeeder(t *models.Torrent, p *models.Peer) error
+	RemoveLeecher(t *models.Torrent, p *models.Peer) error
+	RemoveSeeder(t *models.Torrent, p *models.Peer) error
+	SetLeecher(t *models.Torrent, p *models.Peer) error
+	SetSeeder(t *models.Torrent, p *models.Peer) error
+	IncrementSlots(u *models.User) error
+	DecrementSlots(u *models.User) error
+}