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.

2 files changed, 10 insertions, 5 deletions

diff --git a/src/lib/buf/buffers.c b/src/lib/buf/buffers.c
index 95b384bf06..aa0af69072 100644
--- a/src/lib/buf/buffers.c
+++ b/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. */
diff --git a/src/lib/buf/buffers.h b/src/lib/buf/buffers.h
index d8a77feb72..1361a02eba 100644
--- a/src/lib/buf/buffers.h
+++ b/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);