Optimize extract_info: no process=True for YouTube

For YT, processing separate videos greatly increases extract_info time,
but unnecessary when obtaining only track title.

For Yandex, processing is much faster, and we NEED it to get title.

backend/ydl_pool.py

@@ -36,6 +36,9 @@ create_ydl_fn = {
 
 ydl_fn_keys = create_ydl_fn.keys()
 
+# need process=True for track title in extract_info output
+NP_YDLS = {'yandex'}
+
 
 class Downloader:
 
@@ -51,6 +54,7 @@ class Downloader:
         }
 
         self.cur_ydl: YoutubeDL | None = None
+        self.cur_site = ''
 
         self.progress_cb = progress_cb
         self.lyrics_cb = lyrics_cb
@@ -71,6 +75,7 @@ class Downloader:
                 ydl.params['cookiefile'] = str(cookies)
 
         self.cur_ydl = ydl
+        self.cur_site = site
 
     def get_cur_ydl(self) -> YoutubeDL:
 
@@ -86,12 +91,13 @@ class Downloader:
             Downloader._target_get_playlist_items,
             self.get_cur_ydl(),
             url,
+            self.cur_site in NP_YDLS,
         )
 
     @staticmethod
-    def _target_get_playlist_items(ydl: YoutubeDL, url: str) -> list[str]:
+    def _target_get_playlist_items(ydl: YoutubeDL, url: str, process: bool) -> list[str]:
 
-        info = ydl.extract_info(url, download=False, process=True)
+        info = ydl.extract_info(url, download=False, process=process)
         if info is None:
             raise RuntimeError('ydl.extract_info returned None')
         return [

frontend/index.html

@@ -24,7 +24,7 @@
     </div>
     <div id="items-container"></div>
     <div>
-      <button type="button">Download</button>
+      <button type="button" id="dl-btn">Download</button>
     </div>
     <div>
       <label>Progress: <span id="progress">not implemented</span></label>

frontend/script.js

@@ -15,4 +15,57 @@ addEventListener('DOMContentLoaded', () => {
       site.value = 'yandex'
     }
   })
+
+  const socket = new WebSocket('ws://127.0.0.1:4009')
+
+  const itemsDiv = document.getElementById('items-container')
+  let items = []
+
+  document.getElementById('items-btn').addEventListener('click', () => {
+    socket.send(JSON.stringify({
+      action: 'list',
+      site: site.value,
+      url: urlField.value,
+    }))
+  })
+
+  document.getElementById('dl-btn').addEventListener('click', () => {
+    socket.send(JSON.stringify({
+      action: 'download',
+      site: site.value,
+      url: urlField.value,
+      items: items,
+    }))
+    items = []
+  })
+
+  socket.addEventListener('message', ev => {
+    const msg = JSON.parse(ev.data)
+    switch (msg.type) {
+      case 'items':
+        itemsDiv.textContent = '' // clear
+        const len = msg.data.length
+        for (let i = 1; i <= len; i++) {
+          const itemElem = document.createElement('label')
+          const itemCheckbox = document.createElement('input')
+          itemCheckbox.type = 'checkbox'
+          itemCheckbox.addEventListener('change', () => {
+            if (itemCheckbox.checked) {
+              items.push(i)
+            } else {
+              items.splice(items.indexOf(i), 1)
+            }
+          })
+          itemElem.append(itemCheckbox)
+          itemText = document.createTextNode(msg.data[i - 1])
+          itemElem.append(itemText)
+          itemsDiv.append(itemElem)
+        }
+        break
+      case 'dl_progress':
+        break
+      case 'dl_end':
+        break
+    }
+  })
 })