From c00e11ed2b6e7209e935fc95ea54d467ced7eebf Mon Sep 17 00:00:00 2001
From: csoler <retroshare.project@gmail.com>
Date: Wed, 10 Nov 2010 22:05:34 +0000
Subject: [PATCH] switched random chunk strategy to true random

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@3777 b45a01b8-16f6-495d-af2f-9b41ad6348cc
---
 libretroshare/src/ft/ftchunkmap.cc   | 42 +++++++++++++++++-----------
 libretroshare/src/ft/ftcontroller.cc |  4 +--
 2 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/libretroshare/src/ft/ftchunkmap.cc b/libretroshare/src/ft/ftchunkmap.cc
index 2dbb0b7e9..1efa008a9 100644
--- a/libretroshare/src/ft/ftchunkmap.cc
+++ b/libretroshare/src/ft/ftchunkmap.cc
@@ -392,32 +392,40 @@ uint32_t ChunkMap::getAvailableChunk(const std::string& peer_id,bool& map_is_too
 	else
 		map_is_too_old = false ;// the map is not too old
 
-	uint32_t start_location = (_strategy == FileChunksInfo::CHUNK_STRATEGY_STREAMING)?0:(rand()%_map.size()) ;
+	uint32_t available_chunks = 0 ;
 
 	for(unsigned int i=0;i<_map.size();++i)
-	{
-		uint32_t j = (start_location+i)%(int)_map.size() ;	// index of the chunk
-
-		if(_map[j] == FileChunksInfo::CHUNK_OUTSTANDING && (peer_chunks->is_full || peer_chunks->cmap[j]))
+		if(_map[i] == FileChunksInfo::CHUNK_OUTSTANDING && (peer_chunks->is_full || peer_chunks->cmap[i]))
 		{
 			if(_strategy == FileChunksInfo::CHUNK_STRATEGY_STREAMING)
-				return j ;
-			else
 			{
-				// reserve a series of available chunks
-				//
-				uint32_t k=0 ;
-
-				for(;k+j<_map.size() && (_map[k+j] == FileChunksInfo::CHUNK_OUTSTANDING && (peer_chunks->is_full || peer_chunks->cmap[k+j]));++k) ;
-
 #ifdef DEBUG_FTCHUNK
-				std::cerr << "ChunkMap::getAvailableChunk: returning chunk " << j+k << " for peer " << peer_id << std::endl;
+				std::cerr << "ChunkMap::getAvailableChunk: returning chunk " << i << " for peer " << peer_id << std::endl;
 #endif
-				// ...and select one randomly
-				//
-				return (rand()%k) + j ;
+				return i ;
 			}
+			else
+				++available_chunks ;
 		}
+
+	if(available_chunks > 0)
+	{
+		uint32_t chosen_chunk_number = rand() % available_chunks ;
+		uint32_t j=0 ;
+
+		for(uint32_t i=0;i<_map.size();++i)
+			if(_map[i] == FileChunksInfo::CHUNK_OUTSTANDING && (peer_chunks->is_full || peer_chunks->cmap[i]))
+			{
+				if(j == chosen_chunk_number)
+				{
+#ifdef DEBUG_FTCHUNK
+					std::cerr << "ChunkMap::getAvailableChunk: returning chunk " << i << " for peer " << peer_id << std::endl;
+#endif
+					return i ;
+				}
+				else
+					++j ;
+			}
 	}
 
 #ifdef DEBUG_FTCHUNK
diff --git a/libretroshare/src/ft/ftcontroller.cc b/libretroshare/src/ft/ftcontroller.cc
index a3ba2833d..b64018900 100644
--- a/libretroshare/src/ft/ftcontroller.cc
+++ b/libretroshare/src/ft/ftcontroller.cc
@@ -1194,9 +1194,7 @@ bool 	ftController::FileRequest(const std::string& fname, const std::string& has
 			destination = mDownloadPath + "/" + fname;
 	} /******* UNLOCKED ********/
 
-  // We check that flags are consistent.  In particular, for know
-  // we can't send chunkmaps through normal traffic, so availability must be assumed whenever the traffic is not
-  // a turtle traffic:
+  // We check that flags are consistent.  
   
   	if(flags & RS_FILE_HINTS_NETWORK_WIDE)
 		mTurtle->monitorFileTunnels(fname,hash,size) ;