overhaul everything

drivers/backend/backend.go

@@ -0,0 +1,72 @@
+// 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 backend provides a generic interface for manipulating a
+// BitTorrent tracker's consistent backend data store (usually for
+// a web application).
+package backend
+
+import (
+	"fmt"
+
+	"github.com/chihaya/chihaya/config"
+	"github.com/chihaya/chihaya/models"
+)
+
+var drivers = make(map[string]Driver)
+
+// Driver represents an interface to a long-running connection with a
+// consistent data store.
+type Driver interface {
+	New(*config.DataStore) Conn
+}
+
+// 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("backend: Register driver is nil")
+	}
+	if _, dup := drivers[name]; dup {
+		panic("backend: Register called twice for driver " + name)
+	}
+	drivers[name] = driver
+}
+
+// Open creates a connection specified by a models configuration.
+func Open(conf *config.DataStore) (Conn, error) {
+	driver, ok := drivers[conf.Driver]
+	if !ok {
+		return nil, fmt.Errorf(
+			"backend: unknown driver %q (forgotten import?)",
+			conf.Driver,
+		)
+	}
+	pool := driver.New(conf)
+	return pool, nil
+}
+
+// Conn represents a connection to the data store.
+type Conn interface {
+	// Close terminates connections to the database(s) and gracefully shuts
+	// down the driver
+	Close() error
+
+	// RecordAnnounce is called once per announce, and is passed the delta in
+	// statistics for the client peer since its last announce.
+	RecordAnnounce(delta *models.AnnounceDelta) error
+
+	// LoadTorrents fetches and returns the specified torrents.
+	LoadTorrents(ids []uint64) ([]*models.Torrent, error)
+
+	// LoadAllTorrents fetches and returns all torrents.
+	LoadAllTorrents() ([]*models.Torrent, error)
+
+	// LoadUsers fetches and returns the specified users.
+	LoadUsers(ids []uint64) ([]*models.User, error)
+
+	// LoadAllUsers fetches and returns all users.
+	LoadAllUsers(ids []uint64) ([]*models.User, error)
+}

drivers/backend/mock/driver.go

@@ -0,0 +1,81 @@
+// 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 mock implements the models interface for a BitTorrent tracker's
+// backend models. It can be used in production, but isn't recommended.
+// Stored values will not persist if the tracker is restarted.
+package mock
+
+import (
+	"sync"
+
+	"github.com/chihaya/chihaya/config"
+	"github.com/chihaya/chihaya/drivers/backend"
+	"github.com/chihaya/chihaya/models"
+)
+
+type driver struct{}
+
+// Mock is a concrete implementation of the backend.Conn interface (plus some
+// debugging methods) that stores deltas in memory.
+type Mock struct {
+	deltaHistory  []*models.AnnounceDelta
+	deltaHistoryM sync.RWMutex
+}
+
+func (d *driver) New(conf *config.DataStore) backend.Conn {
+	return &Mock{}
+}
+
+// Close returns nil.
+func (m *Mock) Close() error {
+	return nil
+}
+
+// RecordAnnounce adds a delta to the history.
+func (m *Mock) RecordAnnounce(delta *models.AnnounceDelta) error {
+	m.deltaHistoryM.Lock()
+	defer m.deltaHistoryM.Unlock()
+
+	m.deltaHistory = append(m.deltaHistory, delta)
+
+	return nil
+}
+
+// DeltaHistory safely copies and returns the history of recorded deltas.
+func (m *Mock) DeltaHistory() []models.AnnounceDelta {
+	m.deltaHistoryM.Lock()
+	defer m.deltaHistoryM.Unlock()
+
+	cp := make([]models.AnnounceDelta, len(m.deltaHistory))
+	for index, delta := range m.deltaHistory {
+		cp[index] = *delta
+	}
+
+	return cp
+}
+
+// LoadTorrents returns (nil, nil).
+func (m *Mock) LoadTorrents(ids []uint64) ([]*models.Torrent, error) {
+	return nil, nil
+}
+
+// LoadAllTorrents returns (nil, nil).
+func (m *Mock) LoadAllTorrents() ([]*models.Torrent, error) {
+	return nil, nil
+}
+
+// LoadUsers returns (nil, nil).
+func (m *Mock) LoadUsers(ids []uint64) ([]*models.User, error) {
+	return nil, nil
+}
+
+// LoadAllUsers returns (nil, nil).
+func (m *Mock) LoadAllUsers(ids []uint64) ([]*models.User, error) {
+	return nil, nil
+}
+
+func init() {
+	backend.Register("mock", &driver{})
+}