Remove the connection_t.outbuf_flushlen field

This was once used for rate-limiting, but now it's only for
accounting.  It hasn't served a useful purpose in a long time.

Closes ticket 33097.

src/lib/buf/buffers.c

@@ -685,17 +685,20 @@ buf_move_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen)
 }
 
 /** Moves all data from <b>buf_in</b> to <b>buf_out</b>, without copying.
+ * Return the number of bytes that were moved.
  */
-void
+size_t
 buf_move_all(buf_t *buf_out, buf_t *buf_in)
 {
   tor_assert(buf_out);
   if (!buf_in)
-    return;
+    return 0;
   if (BUG(buf_out->datalen > BUF_MAX_LEN || buf_in->datalen > BUF_MAX_LEN))
-    return;
+    return 0;
   if (BUG(buf_out->datalen > BUF_MAX_LEN - buf_in->datalen))
-    return;
+    return 0;
+
+  size_t n_bytes_moved = buf_in->datalen;
 
   if (buf_out->head == NULL) {
     buf_out->head = buf_in->head;
@@ -708,6 +711,8 @@ buf_move_all(buf_t *buf_out, buf_t *buf_in)
   buf_out->datalen += buf_in->datalen;
   buf_in->head = buf_in->tail = NULL;
   buf_in->datalen = 0;
+
+  return n_bytes_moved;
 }
 
 /** Internal structure: represents a position in a buffer. */

src/lib/buf/buffers.h

@@ -46,7 +46,7 @@ void buf_add_printf(buf_t *buf, const char *format, ...)
 void buf_add_vprintf(buf_t *buf, const char *format, va_list args)
   CHECK_PRINTF(2, 0);
 int buf_move_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen);
-void buf_move_all(buf_t *buf_out, buf_t *buf_in);
+size_t buf_move_all(buf_t *buf_out, buf_t *buf_in);
 void buf_peek(const buf_t *buf, char *string, size_t string_len);
 void buf_drain(buf_t *buf, size_t n);
 int buf_get_bytes(buf_t *buf, char *string, size_t string_len);

src/lib/net/buffers_net.c

@@ -137,13 +137,12 @@ buf_read_from_fd(buf_t *buf, int fd, size_t at_most,
 }
 
 /** Helper for buf_flush_to_socket(): try to write <b>sz</b> bytes from chunk
- * <b>chunk</b> of buffer <b>buf</b> onto file descriptor <b>fd</b>.  On
- * success, deduct the bytes written from *<b>buf_flushlen</b>.  Return the
- * number of bytes written on success, 0 on blocking, -1 on failure.
+ * <b>chunk</b> of buffer <b>buf</b> onto file descriptor <b>fd</b>.  Return
+ * the number of bytes written on success, 0 on blocking, -1 on failure.
  */
 static inline int
 flush_chunk(tor_socket_t fd, buf_t *buf, chunk_t *chunk, size_t sz,
-            size_t *buf_flushlen, bool is_socket)
+            bool is_socket)
 {
   ssize_t write_result;
 
@@ -168,7 +167,6 @@ flush_chunk(tor_socket_t fd, buf_t *buf, chunk_t *chunk, size_t sz,
     log_debug(LD_NET,"write() would block, returning.");
     return 0;
   } else {
-    *buf_flushlen -= write_result;
     buf_drain(buf, write_result);
     tor_assert(write_result <= BUF_MAX_LEN);
     return (int)write_result;
@@ -176,27 +174,22 @@ flush_chunk(tor_socket_t fd, buf_t *buf, chunk_t *chunk, size_t sz,
 }
 
 /** Write data from <b>buf</b> to the file descriptor <b>fd</b>.  Write at most
- * <b>sz</b> bytes, decrement *<b>buf_flushlen</b> by
- * the number of bytes actually written, and remove the written bytes
+ * <b>sz</b> bytes, and remove the written bytes
  * from the buffer.  Return the number of bytes written on success,
  * -1 on failure.  Return 0 if write() would block.
  */
 static int
 buf_flush_to_fd(buf_t *buf, int fd, size_t sz,
-                size_t *buf_flushlen, bool is_socket)
+                bool is_socket)
 {
   /* XXXX It's stupid to overload the return values for these functions:
    * "error status" and "number of bytes flushed" are not mutually exclusive.
    */
   int r;
   size_t flushed = 0;
-  tor_assert(buf_flushlen);
   tor_assert(SOCKET_OK(fd));
-  if (BUG(*buf_flushlen > buf->datalen)) {
-    *buf_flushlen = buf->datalen;
-  }
-  if (BUG(sz > *buf_flushlen)) {
-    sz = *buf_flushlen;
+  if (BUG(sz > buf->datalen)) {
+    sz = buf->datalen;
   }
 
   check();
@@ -208,7 +201,7 @@ buf_flush_to_fd(buf_t *buf, int fd, size_t sz,
     else
       flushlen0 = buf->head->datalen;
 
-    r = flush_chunk(fd, buf, buf->head, flushlen0, buf_flushlen, is_socket);
+    r = flush_chunk(fd, buf, buf->head, flushlen0, is_socket);
     check();
     if (r < 0)
       return r;
@@ -228,10 +221,9 @@ buf_flush_to_fd(buf_t *buf, int fd, size_t sz,
  * -1 on failure.  Return 0 if write() would block.
  */
 int
-buf_flush_to_socket(buf_t *buf, tor_socket_t s, size_t sz,
-                    size_t *buf_flushlen)
+buf_flush_to_socket(buf_t *buf, tor_socket_t s, size_t sz)
 {
-  return buf_flush_to_fd(buf, s, sz, buf_flushlen, true);
+  return buf_flush_to_fd(buf, s, sz, true);
 }
 
 /** Read from socket <b>s</b>, writing onto end of <b>buf</b>.  Read at most
@@ -254,10 +246,9 @@ buf_read_from_socket(buf_t *buf, tor_socket_t s, size_t at_most,
  * -1 on failure.  Return 0 if write() would block.
  */
 int
-buf_flush_to_pipe(buf_t *buf, int fd, size_t sz,
-                  size_t *buf_flushlen)
+buf_flush_to_pipe(buf_t *buf, int fd, size_t sz)
 {
-  return buf_flush_to_fd(buf, fd, sz, buf_flushlen, false);
+  return buf_flush_to_fd(buf, fd, sz, false);
 }
 
 /** Read from pipe <b>fd</b>, writing onto end of <b>buf</b>.  Read at most

src/lib/net/buffers_net.h

@@ -21,14 +21,12 @@ int buf_read_from_socket(struct buf_t *buf, tor_socket_t s, size_t at_most,
                          int *reached_eof,
                          int *socket_error);
 
-int buf_flush_to_socket(struct buf_t *buf, tor_socket_t s, size_t sz,
-                        size_t *buf_flushlen);
+int buf_flush_to_socket(struct buf_t *buf, tor_socket_t s, size_t sz);
 
 int buf_read_from_pipe(struct buf_t *buf, int fd, size_t at_most,
                        int *reached_eof,
                        int *socket_error);
 
-int buf_flush_to_pipe(struct buf_t *buf, int fd, size_t sz,
-                      size_t *buf_flushlen);
+int buf_flush_to_pipe(struct buf_t *buf, int fd, size_t sz);
 
 #endif /* !defined(TOR_BUFFERS_NET_H) */

src/lib/process/process_unix.c

@@ -418,7 +418,7 @@ process_unix_write(process_t *process, buf_t *buffer)
   /* We have data to write and the kernel have told us to write it. */
   return buf_flush_to_pipe(buffer,
                            process_get_unix_process(process)->stdin_handle.fd,
-                           max_to_write, &buffer_flush_len);
+                           max_to_write);
 }
 
 /** Read data from the given process's standard output and put it into

src/lib/tls/buffers_tls.c

@@ -106,8 +106,7 @@ buf_read_from_tls(buf_t *buf, tor_tls_t *tls, size_t at_most)
  * written on success, and a TOR_TLS error code on failure or blocking.
  */
 static inline int
-flush_chunk_tls(tor_tls_t *tls, buf_t *buf, chunk_t *chunk,
-                size_t sz, size_t *buf_flushlen)
+flush_chunk_tls(tor_tls_t *tls, buf_t *buf, chunk_t *chunk, size_t sz)
 {
   int r;
   size_t forced;
@@ -126,13 +125,9 @@ flush_chunk_tls(tor_tls_t *tls, buf_t *buf, chunk_t *chunk,
   r = tor_tls_write(tls, data, sz);
   if (r < 0)
     return r;
-  if (*buf_flushlen > (size_t)r)
-    *buf_flushlen -= r;
-  else
-    *buf_flushlen = 0;
   buf_drain(buf, r);
-  log_debug(LD_NET,"flushed %d bytes, %d ready to flush, %d remain.",
-            r,(int)*buf_flushlen,(int)buf->datalen);
+  log_debug(LD_NET,"flushed %d bytes, %d remain.",
+            r,(int)buf->datalen);
   return r;
 }
 
@@ -140,18 +135,13 @@ flush_chunk_tls(tor_tls_t *tls, buf_t *buf, chunk_t *chunk,
  * more than <b>flushlen</b> bytes.
  */
 int
-buf_flush_to_tls(buf_t *buf, tor_tls_t *tls, size_t flushlen,
-              size_t *buf_flushlen)
+buf_flush_to_tls(buf_t *buf, tor_tls_t *tls, size_t flushlen)
 {
   int r;
   size_t flushed = 0;
   ssize_t sz;
-  tor_assert(buf_flushlen);
-  IF_BUG_ONCE(*buf_flushlen > buf->datalen) {
-    *buf_flushlen = buf->datalen;
-  }
-  IF_BUG_ONCE(flushlen > *buf_flushlen) {
-    flushlen = *buf_flushlen;
+  IF_BUG_ONCE(flushlen > buf->datalen) {
+    flushlen = buf->datalen;
   }
   sz = (ssize_t) flushlen;
 
@@ -170,7 +160,7 @@ buf_flush_to_tls(buf_t *buf, tor_tls_t *tls, size_t flushlen,
       flushlen0 = 0;
     }
 
-    r = flush_chunk_tls(tls, buf, buf->head, flushlen0, buf_flushlen);
+    r = flush_chunk_tls(tls, buf, buf->head, flushlen0);
     if (r < 0)
       return r;
     flushed += r;

src/lib/tls/buffers_tls.h

@@ -18,6 +18,6 @@ struct tor_tls_t;
 int buf_read_from_tls(struct buf_t *buf,
                       struct tor_tls_t *tls, size_t at_most);
 int buf_flush_to_tls(struct buf_t *buf, struct tor_tls_t *tls,
-                     size_t sz, size_t *buf_flushlen);
+                     size_t sz);
 
 #endif /* !defined(TOR_BUFFERS_TLS_H) */