From d07a80dc48a3e1e7564dbef9d8b0ea7189cf9978 Mon Sep 17 00:00:00 2001
From: Jens Axboe <jens.axboe@oracle.com>
Date: Mon, 4 Jun 2007 12:35:37 -0700
Subject: [PATCH] vmsplice-touser: example

---
 Makefile          |   2 +-
 vmsplice-touser.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 115 insertions(+), 1 deletion(-)
 create mode 100644 vmsplice-touser.c

diff --git a/Makefile b/Makefile
index 20255ed..e6a6d53 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 CC	= gcc
 CFLAGS	= -Wall -O2 -g -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
-PROGS	= ktee ktee-net splice-cp splice-in splice-out splice-tonet splice-fromnet splice-test4c splice-test4s vmsplice splice-bench vmsplice2
+PROGS	= ktee ktee-net splice-cp splice-in splice-out splice-tonet splice-fromnet splice-test4c splice-test4s vmsplice splice-bench vmsplice2 vmsplice-touser
 MANS	= splice.2 tee.2 vmsplice.2
 
 all: depend $(PROGS)
diff --git a/vmsplice-touser.c b/vmsplice-touser.c
new file mode 100644
index 0000000..1536904
--- /dev/null
+++ b/vmsplice-touser.c
@@ -0,0 +1,114 @@
+/*
+ * Use vmsplice to splice data from a pipe to user space memory.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <limits.h>
+#include <string.h>
+#include <getopt.h>
+#include <sys/poll.h>
+#include <sys/types.h>
+
+#include "splice.h"
+
+static int do_dump;
+static int splice_flags;
+
+int do_vmsplice(int fd, void *buf, int len)
+{
+	struct pollfd pfd = { .fd = fd, .events = POLLIN, };
+	struct iovec iov;
+	int written;
+	int ret;
+
+	iov.iov_base = buf;
+	iov.iov_len = len;
+	ret = 0;
+
+	while (len) {
+		/*
+		 * in a real app you'd be more clever with poll of course,
+		 * here we are basically just blocking on output room and
+		 * not using the free time for anything interesting.
+		 */
+		if (poll(&pfd, 1, -1) < 0)
+			return error("poll");
+
+		written = vmsplice(fd, &iov, 1, splice_flags);
+
+		if (written < 0)
+			return error("vmsplice");
+		else if (!written)
+			break;
+
+		len -= written;
+		ret += written;
+		if (len) {
+			iov.iov_len -= written;
+			iov.iov_base += written;
+		}
+	}
+
+	return ret;
+}
+
+static int usage(char *name)
+{
+	fprintf(stderr, "| %s [-d(ump)]\n", name);
+	return 1;
+}
+
+static int parse_options(int argc, char *argv[])
+{
+	int c, index = 1;
+
+	while ((c = getopt(argc, argv, "d")) != -1) {
+		switch (c) {
+		case 'd':
+			do_dump = 1;
+			index++;
+			break;
+		default:
+			return -1;
+		}
+	}
+
+	return index;
+}
+
+static void hexdump(unsigned char *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		printf("%02x", buf[i]);
+	printf("\n");
+}
+
+int main(int argc, char *argv[])
+{
+	unsigned char *buf;
+	int ret;
+
+	if (parse_options(argc, argv) < 0)
+		return usage(argv[0]);
+
+	if (check_input_pipe())
+		return usage(argv[0]);
+
+	buf = malloc(4096);
+
+	memset(buf, 0, 4096);
+
+	ret = do_vmsplice(STDIN_FILENO, buf, 4096);
+	if (ret < 0)
+		return 1;
+
+	printf("splice %d\n", ret);
+
+	if (do_dump)
+		hexdump(buf, ret);
+
+	return 0;
+}
-- 
2.25.1