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	optimize binary file transfers: use sendfile(2) syscall if supported - geomyida…
	git clone git://bitreich.org/geomyidae/ git://enlrupgkhuxnvlhsf6lc3fziv5h2hhfri…
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	---
	commit d8b18c7bfa0d75f38bbceefde217c83813473e5f
	parent 1c6dfdef1faabdb80161e5490526491e2a02c28c
	Author: Hiltjo Posthuma <[email protected]>
	Date: Sat, 23 Sep 2017 16:08:28 +0200

	optimize binary file transfers: use sendfile(2) syscall if supported

	The OS supporting sendfile(2) are (for now): Linux, FreeBSD, DragonFlyBSD.

	When the file is empty or has no filesize information (such as block,
	character devices etc) fallback to the normal read/write loop in userland.
	A platform with no sendfile(2) support always uses this loop.

	Optimize the buffer size in the normal read/write loop by using the block size
	information, fallback to BUFSIZ.

	Set socket options TCP_CORK (Linux), TCP_NOPUSH (BSDs) and TCP_NODELAY to
	optimize packet transfers for large file transfers.

	Tested on Linux (glibc and musl), FreeBSD, DragonFlyBSD and OpenBSD.

	Signed-off-by: Christoph Lohmann <[email protected]>

	Diffstat:
	M handlr.c \| 14 +++-----------
	M ind.c \| 68 +++++++++++++++++++++++++++++…
	M ind.h \| 1 +

	3 files changed, 72 insertions(+), 11 deletions(-)
	---
	diff --git a/handlr.c b/handlr.c
	@@ -104,8 +104,7 @@ void
	handlebin(int sock, char file, char port, char base, char args,
	char sear, char ohost)
	{
	- char sendb[1024];
	- int len, fd, sent;
	+ int fd;

	USED(port);
	USED(base);
	@@ -115,15 +114,8 @@ handlebin(int sock, char file, char port, char *base, ch…

	fd = open(file, O_RDONLY);
	if(fd >= 0) {
	- while((len = read(fd, sendb, sizeof(sendb))) > 0) {
	- while(len > 0) {
	- if ((sent = send(sock, sendb, len, 0)) < 0) {
	- close(fd);
	- return;
	- }
	- len -= sent;
	- }
	- }
	+ if(xsendfile(fd, sock) < 0)
	+ perror("sendfile");
	close(fd);
	}
	}
	diff --git a/ind.c b/ind.c
	@@ -12,9 +12,19 @@
	#include <stdlib.h>
	#include <netdb.h>
	#include <sys/socket.h>
	+#include <sys/stat.h>
	#include <netinet/in.h>
	+#include <netinet/tcp.h>
	#include <arpa/inet.h>

	+/* for sendfile(2) */
	+#ifdef __linux__
	+#include <sys/sendfile.h>
	+#elif defined(__FreeBSD__) \|\| defined(__DragonFly__)
	+#include <sys/types.h>
	+#include <sys/uio.h>
	+#endif
	+
	#include "ind.h"
	#include "handlr.h"

	@@ -42,6 +52,64 @@ filetype type[] = {
	{nil, nil, nil},
	};

	+int
	+xsendfile(int fd, int sock)
	+{
	+ struct stat st;
	+ char *sendb;
	+ size_t bufsiz = BUFSIZ, count = 0;
	+ int len, sent, optval;
	+
	+#ifdef TCP_CORK
	+ optval = 1;
	+ setsockopt(sock, IPPROTO_TCP, TCP_CORK, &optval, sizeof(int));
	+#endif
	+
	+#ifdef TCP_NOPUSH
	+ optval = 1;
	+ setsockopt(sock, IPPROTO_TCP, TCP_NOPUSH, &optval, sizeof(int));
	+#endif
	+
	+#ifdef TCP_NODELAY
	+ optval = 0;
	+ setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &optval, sizeof(int));
	+#endif
	+
	+ if(fstat(fd, &st) >= 0) {
	+ if((bufsiz = st.st_blksize) < BUFSIZ)
	+ bufsiz = BUFSIZ;
	+ count = st.st_size;
	+ }
	+
	+#if !defined(__linux__) && !defined(__FreeBSD__) && !defined(__DragonFly__)
	+ count = 0;
	+#endif
	+
	+ if (count == 0) {
	+ sendb = xmalloc(bufsiz);
	+ while((len = read(fd, sendb, bufsiz)) > 0) {
	+ while(len > 0) {
	+ if ((sent = send(sock, sendb, len, 0)) < 0) {
	+ close(fd);
	+ free(sendb);
	+ return -1;
	+ }
	+ len -= sent;
	+ }
	+ }
	+ free(sendb);
	+ return 0;
	+ }
	+
	+#ifdef __linux__
	+ return sendfile(sock, fd, NULL, count);
	+#endif
	+#if defined(__FreeBSD__) \|\| defined(__DragonFly__)
	+ return sendfile(fd, sock, 0, count, NULL, NULL, 0);
	+#endif
	+ return -1;
	+}
	+
	void *
	xcalloc(size_t nmemb, size_t size)
	{
	diff --git a/ind.h b/ind.h
	@@ -35,6 +35,7 @@ void *xcalloc(size_t, size_t);
	void *xmalloc(size_t);
	void xrealloc(void , size_t);
	char xstrdup(const char str);
	+int xsendfile(int, int);
	Indexs scanfile(char fname);
	Elems getadv(char str);
	int printelem(int fd, Elems el, char addr, char *port);