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authorShooterIT <wangyuancode@163.com>2020-04-14 23:56:34 +0800
committerShooterIT <wangyuancode@163.com>2020-04-14 23:56:34 +0800
commit9cf500a3f67e4e2ce51414c354e3472faf095d5b (patch)
treebbb2b6f9fdd91ffaed655fe0e7a28e8275eede00
parent7428f5121755f0f49aaf5f46321da64cd122aa1a (diff)
downloadredis-9cf500a3f67e4e2ce51414c354e3472faf095d5b.tar.gz
Implements sendfile for redis.
-rw-r--r--src/config.h6
-rw-r--r--src/replication.c51
2 files changed, 55 insertions, 2 deletions
diff --git a/src/config.h b/src/config.h
index efa9d11f2..058d73932 100644
--- a/src/config.h
+++ b/src/config.h
@@ -133,6 +133,12 @@ void setproctitle(const char *fmt, ...);
/* Byte ordering detection */
#include <sys/types.h> /* This will likely define BYTE_ORDER */
+/* Define redis_sendfile. */
+#if defined(__linux__) || (defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_5))
+#define HAVE_SENDFILE 1
+ssize_t redis_sendfile(int out_fd, int in_fd, off_t offset, size_t count);
+#endif
+
#ifndef BYTE_ORDER
#if (BSD >= 199103)
# include <machine/endian.h>
diff --git a/src/replication.c b/src/replication.c
index 3e9910374..4a3bbbdcf 100644
--- a/src/replication.c
+++ b/src/replication.c
@@ -972,10 +972,41 @@ void removeRDBUsedToSyncReplicas(void) {
}
}
+#if HAVE_SENDFILE
+/* Implements redis_sendfile to transfer data between file descriptors and
+ * avoid transferring data to and from user space.
+ *
+ * The function prototype is just like sendfile(2) on Linux. in_fd is a file
+ * descriptor opened for reading and out_fd is a descriptor opened for writing.
+ * offset specifies where to start reading data from in_fd. count is the number
+ * of bytes to copy between the file descriptors.
+ *
+ * The return value is the number of bytes written to out_fd, if the transfer
+ * was successful. On error, -1 is returned, and errno is set appropriately. */
+ssize_t redis_sendfile(int out_fd, int in_fd, off_t offset, size_t count) {
+#if defined(__linux__)
+ #include <sys/sendfile.h>
+ return sendfile(out_fd, in_fd, &offset, count);
+
+#elif defined(__APPLE__)
+ off_t len = count;
+ /* Notice that it may return -1 and errno is set to EAGAIN even if some
+ * bytes have been sent successfully and the len argument is set correctly
+ * when using a socket marked for non-blocking I/O. */
+ if (sendfile(in_fd, out_fd, offset, &len, NULL, 0) == -1 &&
+ errno != EAGAIN) return -1;
+ else
+ return (ssize_t)len;
+
+#endif
+ errno = ENOSYS;
+ return -1;
+}
+#endif
+
void sendBulkToSlave(connection *conn) {
client *slave = connGetPrivateData(conn);
- char buf[PROTO_IOBUF_LEN];
- ssize_t nwritten, buflen;
+ ssize_t nwritten;
/* Before sending the RDB file, we send the preamble as configured by the
* replication process. Currently the preamble is just the bulk count of
@@ -1001,6 +1032,21 @@ void sendBulkToSlave(connection *conn) {
}
/* If the preamble was already transferred, send the RDB bulk data. */
+#if HAVE_SENDFILE
+ if ((nwritten = redis_sendfile(conn->fd,slave->repldbfd,
+ slave->repldboff,PROTO_IOBUF_LEN)) == -1)
+ {
+ if (errno != EAGAIN) {
+ serverLog(LL_WARNING,"Sendfile error sending DB to replica: %s",
+ strerror(errno));
+ freeClient(slave);
+ }
+ return;
+ }
+#else
+ ssize_t buflen;
+ char buf[PROTO_IOBUF_LEN];
+
lseek(slave->repldbfd,slave->repldboff,SEEK_SET);
buflen = read(slave->repldbfd,buf,PROTO_IOBUF_LEN);
if (buflen <= 0) {
@@ -1017,6 +1063,7 @@ void sendBulkToSlave(connection *conn) {
}
return;
}
+#endif
slave->repldboff += nwritten;
server.stat_net_output_bytes += nwritten;
if (slave->repldboff == slave->repldbsize) {