redis-cli pipe mode: don't stay in the write loop forever.

The code was broken and resulted in redis-cli --pipe to, most of the
times, writing everything received in the standard input to the Redis
connection socket without ever reading back the replies, until all the
content to write was written.

This means that Redis had to accumulate all the output in the output
buffers of the client, consuming a lot of memory.

Fixed thanks to the original report of anomalies in the behavior
provided by Twitter user @fsaintjacques.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/redis-cli.c b/src/redis-cli.c
index 825162b81..92e294127 100644
--- a/src/redis-cli.c
+++ b/src/redis-cli.c
@@ -1397,6 +1397,7 @@ static void getRDB(void) {
  * Bulk import (pipe) mode
  *--------------------------------------------------------------------------- */
 
+#define PIPEMODE_WRITE_LOOP_MAX_BYTES (128*1024)
 static void pipeMode(void) {
     int fd = context->fd;
     long long errors = 0, replies = 0, obuf_len = 0, obuf_pos = 0;
@@ -1473,6 +1474,8 @@ static void pipeMode(void) {
 
         /* Handle the writable state: we can send protocol to the server. */
         if (mask & AE_WRITABLE) {
+            ssize_t loop_nwritten = 0;
+
             while(1) {
                 /* Transfer current buffer to server. */
                 if (obuf_len != 0) {
@@ -1489,6 +1492,7 @@ static void pipeMode(void) {
                     }
                     obuf_len -= nwritten;
                     obuf_pos += nwritten;
+                    loop_nwritten += nwritten;
                     if (obuf_len != 0) break; /* Can't accept more data. */
                 }
                 /* If buffer is empty, load from stdin. */
@@ -1524,7 +1528,8 @@ static void pipeMode(void) {
                         obuf_pos = 0;
                     }
                 }
-                if (obuf_len == 0 && eof) break;
+                if ((obuf_len == 0 && eof) ||
+                    loop_nwritten > PIPEMODE_WRITE_LOOP_MAX_BYTES) break;
             }
         }