Get cached message count

app/src/main/java/com/sun/mail/imap/IMAPFolder.java

@@ -1659,6 +1659,28 @@ public class IMAPFolder extends Folder implements UIDFolder, ResponseHandler {
 	}
     }
 
+	public synchronized int getCachedCount() {
+		synchronized (messageCacheLock) {
+			if (messageCache == null)
+				return -1;
+
+			try {
+				int count = 0;
+				int size = messageCache.size();
+				for (int i = 1; i <= size; i++) {
+					Message message = messageCache.getMessage(i);
+					if (message != null && !message.isExpunged())
+						count++;
+				}
+
+				return count;
+			} catch (Throwable ex) {
+				eu.faircode.email.Log.e(ex);
+				return -1;
+			}
+		}
+	}
+
     /**
      * Get the new message count.
      */

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -29,6 +29,7 @@ import androidx.documentfile.provider.DocumentFile;
 import androidx.preference.PreferenceManager;
 
 import com.sun.mail.gimap.GmailMessage;
+import com.sun.mail.imap.IMAPFolder;
 import com.sun.mail.imap.IMAPMessage;
 import com.sun.mail.util.ASCIIUtility;
 import com.sun.mail.util.BASE64DecoderStream;
@@ -2286,6 +2287,13 @@ public class MessageHelper {
 
     static int getMessageCount(Folder folder) {
         try {
+            // Prevent pool lock
+            if (folder instanceof IMAPFolder) {
+                int count = ((IMAPFolder) folder).getCachedCount();
+                Log.i(folder.getFullName() + " total count=" + count);
+                return count;
+            }
+
             int count = 0;
             for (Message message : folder.getMessages())
                 if (!message.isExpunged())