From 12de56d09f34360b97cfbd61920fc253eb34349d Mon Sep 17 00:00:00 2001
From: Wilfried Goesgens <dothebart@citadel.org>
Date: Sun, 10 Jun 2012 17:12:58 +0200
Subject: [PATCH] FileSendChunked(): replace sendfile by splice()
 FileSendChunked+FileRecvChunked: handle situations in which the first splice
 reads more then the second can send.

---
 libcitadel/lib/libcitadel.h |  1 +
 libcitadel/lib/stringbuf.c  | 55 +++++++++++++++++++++++++++----------
 2 files changed, 41 insertions(+), 15 deletions(-)

diff --git a/libcitadel/lib/libcitadel.h b/libcitadel/lib/libcitadel.h
index 3eee3728f..4258341c1 100644
--- a/libcitadel/lib/libcitadel.h
+++ b/libcitadel/lib/libcitadel.h
@@ -255,6 +255,7 @@ typedef struct __fd_iobuffer {
 	IOBuffer *IOB;
 	int OtherFD;
 	int SplicePipe[2];
+	int PipeSize;
 	long TotalSendSize;
 	long TotalSentAlready;
 	long ChunkSize;
diff --git a/libcitadel/lib/stringbuf.c b/libcitadel/lib/stringbuf.c
index 359538d96..79b5f5d2f 100644
--- a/libcitadel/lib/stringbuf.c
+++ b/libcitadel/lib/stringbuf.c
@@ -3909,17 +3909,38 @@ void FDIOBufferDelete(FDIOBuffer *FDB)
 
 int FileSendChunked(FDIOBuffer *FDB, const char **Err)
 {
+	ssize_t sent, pipesize;
 #ifdef LINUX_SPLICE
-	ssize_t sent;
-	sent = sendfile(FDB->IOB->fd, FDB->OtherFD, &FDB->TotalSentAlready, FDB->ChunkSendRemain);
+	if (FDB->PipeSize == 0)
+	{
+		pipesize = splice(FDB->OtherFD,
+				  &FDB->TotalSentAlready, 
+				  FDB->SplicePipe[1],
+				  NULL, 
+				  FDB->ChunkSendRemain, 
+				  SPLICE_F_MOVE);
+	
+		if (pipesize == -1)
+		{
+			*Err = strerror(errno);
+			return pipesize;
+		}
+		FDB->PipeSize = pipesize;
+	}
+	sent =  splice(FDB->SplicePipe[0],
+		       NULL, 
+		       FDB->IOB->fd,
+		       NULL, 
+		       FDB->PipeSize,
+		       SPLICE_F_MORE | SPLICE_F_MOVE | SPLICE_F_NONBLOCK);
 	if (sent == -1)
 	{
 		*Err = strerror(errno);
 		return sent;
 	}
+	FDB->PipeSize -= sent;
 	FDB->ChunkSendRemain -= sent;
-	FDB->TotalSentAlready += sent;
-	return FDB->ChunkSendRemain;
+	return sent;
 #else
 
 	char *pRead;
@@ -3956,18 +3977,21 @@ int FileRecvChunked(FDIOBuffer *FDB, const char **Err)
 	ssize_t sent, pipesize;
 
 #ifdef LINUX_SPLICE
-
-	pipesize = splice(FDB->IOB->fd,
-			  NULL, 
-			  FDB->SplicePipe[1],
-			  NULL, 
-			  FDB->ChunkSendRemain, 
-			  SPLICE_F_MORE | SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
-
-	if (pipesize == -1)
+	if (FDB->PipeSize == 0)
 	{
-		*Err = strerror(errno);
-		return pipesize;
+		pipesize = splice(FDB->IOB->fd,
+				  NULL, 
+				  FDB->SplicePipe[1],
+				  NULL, 
+				  FDB->ChunkSendRemain, 
+				  SPLICE_F_MORE | SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
+
+		if (pipesize == -1)
+		{
+			*Err = strerror(errno);
+			return pipesize;
+		}
+		FDB->PipeSize = pipesize;
 	}
 	
 	sent = splice(FDB->SplicePipe[0],
@@ -3982,6 +4006,7 @@ int FileRecvChunked(FDIOBuffer *FDB, const char **Err)
 		*Err = strerror(errno);
 		return sent;
 	}
+	FDB->PipeSize -= sent;
 	FDB->ChunkSendRemain -= sent;
 	return sent;
 #else
-- 
2.30.2