1 files changed, 305 insertions, 0 deletions
diff --git a/matrix/rooms/roomcache.go b/matrix/rooms/roomcache.go
new file mode 100644
index 0000000..03e3ad8
--- /dev/null
+++ b/matrix/rooms/roomcache.go
@@ -0,0 +1,305 @@
+// gomuks - A terminal Matrix client written in Go.
+// Copyright (C) 2019 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package rooms
+
+import (
+	"compress/gzip"
+	"encoding/gob"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/pkg/errors"
+	sync "github.com/sasha-s/go-deadlock"
+
+	"maunium.net/go/gomuks/debug"
+)
+
+// RoomCache contains room state info in a hashmap and linked list.
+type RoomCache struct {
+	sync.Mutex
+
+	listPath  string
+	directory string
+	maxSize   int
+	maxAge    int64
+	getOwner  func() string
+
+	Map  map[string]*Room
+	head *Room
+	tail *Room
+	size int
+}
+
+func NewRoomCache(listPath, directory string, maxSize int, maxAge int64, getOwner func() string) *RoomCache {
+	return &RoomCache{
+		listPath:  listPath,
+		directory: directory,
+		maxSize:   maxSize,
+		maxAge:    maxAge,
+		getOwner:  getOwner,
+
+		Map: make(map[string]*Room),
+	}
+}
+
+func (cache *RoomCache) LoadList() error {
+	cache.Lock()
+	defer cache.Unlock()
+
+	// Open room list file
+	file, err := os.OpenFile(cache.listPath, os.O_RDONLY, 0600)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return errors.Wrap(err, "failed to open room list file for reading")
+	}
+	defer debugPrintError(file.Close, "Failed to close room list file after reading")
+
+	// Open gzip reader for room list file
+	cmpReader, err := gzip.NewReader(file)
+	if err != nil {
+		return errors.Wrap(err, "failed to read gzip room list")
+	}
+	defer debugPrintError(cmpReader.Close, "Failed to close room list gzip reader")
+
+	// Open gob decoder for gzip reader
+	dec := gob.NewDecoder(cmpReader)
+	// Read number of items in list
+	var size int
+	err = dec.Decode(&size)
+	if err != nil {
+		return errors.Wrap(err, "failed to read size of room list")
+	}
+
+	// Read list
+	cache.Map = make(map[string]*Room, size)
+	for i := 0; i < size; i++ {
+		room := &Room{}
+		err = dec.Decode(room)
+		if err != nil {
+			debug.Printf("Failed to decode %dth room list entry: %v", i+1, err)
+			continue
+		}
+		room.path = cache.roomPath(room.ID)
+		room.cache = cache
+		cache.Map[room.ID] = room
+	}
+	return nil
+}
+
+func (cache *RoomCache) SaveLoadedRooms() {
+	cache.Lock()
+	defer cache.Unlock()
+	cache.clean()
+	for node := cache.head; node != nil; node = node.prev {
+		node.Save()
+	}
+}
+
+func (cache *RoomCache) SaveList() error {
+	cache.Lock()
+	defer cache.Unlock()
+
+	debug.Print("Saving room list...")
+	// Open room list file
+	file, err := os.OpenFile(cache.listPath, os.O_WRONLY|os.O_CREATE, 0600)
+	if err != nil {
+		return errors.Wrap(err, "failed to open room list file for writing")
+	}
+	defer debugPrintError(file.Close, "Failed to close room list file after writing")
+
+	// Open gzip writer for room list file
+	cmpWriter := gzip.NewWriter(file)
+	defer debugPrintError(cmpWriter.Close, "Failed to close room list gzip writer")
+
+	// Open gob encoder for gzip writer
+	enc := gob.NewEncoder(cmpWriter)
+	// Write number of items in list
+	err = enc.Encode(len(cache.Map))
+	if err != nil {
+		return errors.Wrap(err, "failed to write size of room list")
+	}
+
+	// Write list
+	for _, node := range cache.Map {
+		err = enc.Encode(node)
+		if err != nil {
+			debug.Printf("Failed to encode room list entry of %s: %v", node.ID, err)
+		}
+	}
+	debug.Print("Room list saved to", cache.listPath, len(cache.Map), cache.size)
+	return nil
+}
+
+func (cache *RoomCache) Touch(roomID string) {
+	cache.Lock()
+	node, ok := cache.Map[roomID]
+	if !ok || node == nil {
+		cache.Unlock()
+		return
+	}
+	cache.touch(node)
+	cache.Unlock()
+}
+
+func (cache *RoomCache) TouchNode(node *Room) {
+	cache.Lock()
+	cache.touch(node)
+	cache.Unlock()
+}
+
+func (cache *RoomCache) touch(node *Room) {
+	if node == cache.head {
+		return
+	}
+	debug.Print("Touching", node.ID)
+	cache.llPop(node)
+	cache.llPush(node)
+	node.touch = time.Now().Unix()
+}
+
+func (cache *RoomCache) Get(roomID string) *Room {
+	cache.Lock()
+	node := cache.get(roomID)
+	cache.Unlock()
+	return node
+}
+
+func (cache *RoomCache) GetOrCreate(roomID string) *Room {
+	cache.Lock()
+	node := cache.get(roomID)
+	if node == nil {
+		node = cache.newRoom(roomID)
+		cache.llPush(node)
+	}
+	cache.Unlock()
+	return node
+}
+
+func (cache *RoomCache) get(roomID string) *Room {
+	node, ok := cache.Map[roomID]
+	if ok && node != nil && node.Loaded() {
+		cache.touch(node)
+		return node
+	}
+	return nil
+}
+func (cache *RoomCache) Put(room *Room) {
+	cache.Lock()
+	node := cache.get(room.ID)
+	if node != nil {
+		cache.touch(node)
+	} else {
+		cache.Map[room.ID] = room
+		if room.Loaded() {
+			cache.llPush(room)
+		}
+		node = room
+	}
+	cache.Unlock()
+	node.Save()
+}
+
+func (cache *RoomCache) roomPath(roomID string) string {
+	return filepath.Join(cache.directory, roomID+".gob.gz")
+}
+
+func (cache *RoomCache) Load(roomID string) *Room {
+	cache.Lock()
+	defer cache.Unlock()
+	node, ok := cache.Map[roomID]
+	if ok {
+		return node
+	}
+
+	node = NewRoom(roomID, cache)
+	node.Load()
+	return node
+}
+
+func (cache *RoomCache) llPop(node *Room) {
+	if node.prev == nil && node.next == nil {
+		return
+	}
+	if node.prev != nil {
+		node.prev.next = node.next
+	}
+	if node.next != nil {
+		node.next.prev = node.prev
+	}
+	if node == cache.tail {
+		cache.tail = node.next
+	}
+	if node == cache.head {
+		cache.head = node.prev
+	}
+	node.next = nil
+	node.prev = nil
+	cache.size--
+}
+
+func (cache *RoomCache) llPush(node *Room) {
+	if node.next != nil || node.prev != nil {
+		debug.PrintStack()
+		debug.Print("Tried to llPush node that is already in stack")
+		return
+	}
+	if node == cache.head {
+		return
+	}
+	if cache.head != nil {
+		cache.head.next = node
+	}
+	node.prev = cache.head
+	node.next = nil
+	cache.head = node
+	if cache.tail == nil {
+		cache.tail = node
+	}
+	cache.size++
+	cache.clean()
+}
+
+func (cache *RoomCache) clean() {
+	origSize := cache.size
+	maxTS := time.Now().Unix() - cache.maxAge
+	for cache.size > cache.maxSize {
+		if cache.tail.touch > maxTS {
+			break
+		}
+		cache.tail.Unload()
+		cache.llPop(cache.tail)
+	}
+	if cleaned := origSize - cache.size; cleaned > 0 {
+		debug.Print("Cleaned", cleaned, "rooms")
+	}
+}
+
+func (cache *RoomCache) Unload(node *Room) {
+	cache.Lock()
+	defer cache.Unlock()
+	cache.llPop(node)
+	node.Unload()
+}
+
+func (cache *RoomCache) newRoom(roomID string) *Room {
+	node := NewRoom(roomID, cache)
+	cache.Map[node.ID] = node
+	return node
+}