From 05dea702c35f30a42c293fc76a337e9d8125abb2 Mon Sep 17 00:00:00 2001
From: Fabian Schlenz <mail@fabianonline.de>
Date: Mon, 11 Jul 2016 06:21:34 +0200
Subject: [PATCH] Randomly choose file download block sizes in the hope of
 getting rid of FLOOD_WARN errors.

---
 src/main/java/de/fabianonline/telegram_backup/Config.java   | 6 +++++-
 .../de/fabianonline/telegram_backup/DownloadManager.java    | 4 +++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/main/java/de/fabianonline/telegram_backup/Config.java b/src/main/java/de/fabianonline/telegram_backup/Config.java
index 4b526d2..7714d42 100644
--- a/src/main/java/de/fabianonline/telegram_backup/Config.java
+++ b/src/main/java/de/fabianonline/telegram_backup/Config.java
@@ -34,7 +34,11 @@ public class Config {
     public static final String FILE_FILES_BASE = "files";
     public static final String FILE_STICKER_BASE = "stickers";
 
-    public static final int FILE_DOWNLOAD_BLOCK_SIZE = 1*1024*1024;
+    public static final int[] FILE_DOWNLOAD_BLOCK_SIZES = new int[]{
+    	1*1024*1024,
+    	512*1024,
+    	2*1024*1024,
+    	4*1024*1024};
     
     public static int DELAY_AFTER_GET_MESSAGES = 200;
     public static int DELAY_AFTER_GET_FILE = 1000;
diff --git a/src/main/java/de/fabianonline/telegram_backup/DownloadManager.java b/src/main/java/de/fabianonline/telegram_backup/DownloadManager.java
index 503e810..5f76844 100644
--- a/src/main/java/de/fabianonline/telegram_backup/DownloadManager.java
+++ b/src/main/java/de/fabianonline/telegram_backup/DownloadManager.java
@@ -38,6 +38,7 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.util.ArrayList;
 import java.util.LinkedList;
+import java.util.Random;
 import java.net.URL;
 import java.util.concurrent.TimeoutException;
 
@@ -221,7 +222,8 @@ public class DownloadManager {
 			int offset = 0;
 			TLFile response;
 			do {
-				TLRequestUploadGetFile req = new TLRequestUploadGetFile(loc, offset, Config.FILE_DOWNLOAD_BLOCK_SIZE);
+				int block_size = Config.FILE_DOWNLOAD_BLOCK_SIZES[new Random().nextInt(Config.FILE_DOWNLOAD_BLOCK_SIZES.length)];
+				TLRequestUploadGetFile req = new TLRequestUploadGetFile(loc, offset, block_size);
 				if (dcID==null) {
 					response = (TLFile) client.executeRpcQuery(req);
 				} else {