??

server/memory_db.go

@@ -0,0 +1,121 @@
+package server
+
+import (
+	"log"
+	"os"
+	"sync"
+
+	"github.com/goccy/go-json"
+
+	"github.com/google/uuid"
+	"github.com/marcopeocchi/yt-dlp-web-ui/server/cli"
+)
+
+// In-Memory volatile Thread-Safe Key-Value Storage
+type MemoryDB struct {
+	table map[string]*Process
+	mu    sync.Mutex
+}
+
+// Inits the db with an empty map of string->Process pointer
+func (m *MemoryDB) New() {
+	m.table = make(map[string]*Process)
+}
+
+// Get a process pointer given its id
+func (m *MemoryDB) Get(id string) *Process {
+	m.mu.Lock()
+	res := m.table[id]
+	m.mu.Unlock()
+	return res
+}
+
+// Store a pointer of a process and return its id
+func (m *MemoryDB) Set(process *Process) string {
+	id := uuid.Must(uuid.NewRandom()).String()
+	m.mu.Lock()
+	m.table[id] = process
+	m.mu.Unlock()
+	return id
+}
+
+// Update a process info/metadata, given the process id
+func (m *MemoryDB) Update(id string, info DownloadInfo) {
+	m.mu.Lock()
+	if m.table[id] != nil {
+		m.table[id].Info = info
+	}
+	m.mu.Unlock()
+}
+
+// Update a process progress data, given the process id
+// Used for updating completition percentage or ETA
+func (m *MemoryDB) UpdateProgress(id string, progress DownloadProgress) {
+	m.mu.Lock()
+	if m.table[id] != nil {
+		m.table[id].Progress = progress
+	}
+	m.mu.Unlock()
+}
+
+// Removes a process progress, given the process id
+func (m *MemoryDB) Delete(id string) {
+	m.mu.Lock()
+	delete(m.table, id)
+	m.mu.Unlock()
+}
+
+// Returns a slice of all currently stored processes id
+func (m *MemoryDB) Keys() []string {
+	m.mu.Lock()
+	keys := make([]string, len(m.table))
+	i := 0
+	for k := range m.table {
+		keys[i] = k
+		i++
+	}
+	m.mu.Unlock()
+	return keys
+}
+
+// Returns a slice of all currently stored processes progess
+func (m *MemoryDB) All() []ProcessResponse {
+	running := make([]ProcessResponse, len(m.table))
+	i := 0
+	for k, v := range m.table {
+		if v != nil {
+			running[i] = ProcessResponse{
+				Id:       k,
+				Info:     v.Info,
+				Progress: v.Progress,
+			}
+			i++
+		}
+	}
+	return running
+}
+
+// WIP: Persist the database in a single file named "session.dat"
+func (m *MemoryDB) Persist() {
+	running := m.All()
+
+	session, err := json.Marshal(Session{
+		Processes: running,
+	})
+	if err != nil {
+		log.Println(cli.Red, "Failed to persist database", cli.Reset)
+		return
+	}
+
+	err = os.WriteFile("session.dat", session, 0700)
+	if err != nil {
+		log.Println(cli.Red, "Failed to persist database", cli.Reset)
+	}
+}
+
+// WIP: Restore a persisted state
+func (m *MemoryDB) Restore() {
+	feed, _ := os.ReadFile("session.dat")
+	session := Session{}
+	json.Unmarshal(feed, &session)
+}