[svn] New option `--limit-rate'.

[wget] / src / retr.c

diff --git a/src/retr.c b/src/retr.c
index f4b80fdd50b609f8289653c7a8ee2b073403ca81..9930cc1e0f4782bf27eea814672329ca344e2696 100644 (file)
--- a/src/retr.c
+++ b/src/retr.c
@@ -52,6 +52,50 @@ extern int errno;
 int global_download_count;
 
 \f
+static struct {
+  long bytes;
+  long dltime;
+} limit_data;
+
+static void
+limit_bandwidth_reset (void)
+{
+  limit_data.bytes  = 0;
+  limit_data.dltime = 0;
+}
+
+/* Limit the bandwidth by pausing the download for an amount of time.
+   BYTES is the number of bytes received from the network, DELTA is
+   how long it took to receive them, DLTIME the current download time,
+   TIMER the timer, and ADJUSTMENT the previous.  */
+
+static void
+limit_bandwidth (long bytes, long delta)
+{
+  long expected;
+
+  limit_data.bytes += bytes;
+  limit_data.dltime += delta;
+
+  expected = (long)(1000.0 * limit_data.bytes / opt.limit_rate);
+
+  if (expected > limit_data.dltime)
+    {
+      long slp = expected - limit_data.dltime;
+      if (slp < 200)
+       {
+         DEBUGP (("deferring a %ld ms sleep (%ld/%ld) until later.\n",
+                  slp, limit_data.bytes, limit_data.dltime));
+         return;
+       }
+      DEBUGP (("sleeping %ld ms\n", slp));
+      usleep (1000 * slp);
+    }
+
+  limit_data.bytes = 0;
+  limit_data.dltime = 0;
+}
+
 #define MIN(i, j) ((i) <= (j) ? (i) : (j))
 
 /* Reads the contents of file descriptor FD, until it is closed, or a
@@ -82,14 +126,13 @@ get_contents (int fd, FILE *fp, long *len, long restval, long expected,
   int res = 0;
   static char c[8192];
   void *progress = NULL;
-  struct wget_timer *timer = NULL;
+  struct wget_timer *timer = wtimer_allocate ();
+  long dltime = 0, last_dltime = 0;
 
   *len = restval;
 
   if (opt.verbose)
     progress = progress_create (restval, expected);
-  if (opt.verbose || elapsed != NULL)
-    timer = wtimer_new ();
 
   if (rbuf && RBUF_FD (rbuf) == fd)
     {
@@ -108,8 +151,13 @@ get_contents (int fd, FILE *fp, long *len, long restval, long expected,
          goto out;
        }
       if (opt.verbose)
-       progress_update (progress, sz, wtimer_elapsed (timer));
+       progress_update (progress, sz, 0);
     }
+
+  if (opt.limit_rate)
+    limit_bandwidth_reset ();
+  wtimer_reset (timer);
+
   /* Read from fd while there is available data.
 
      Normally, if expected is 0, it means that it is not known how
@@ -121,14 +169,12 @@ get_contents (int fd, FILE *fp, long *len, long restval, long expected,
                            ? MIN (expected - *len, sizeof (c))
                            : sizeof (c));
 #ifdef HAVE_SSL
-               if (rbuf->ssl!=NULL) {
-                 res = ssl_iread (rbuf->ssl, c, amount_to_read);
-               } else {
-#endif /* HAVE_SSL */
-                 res = iread (fd, c, amount_to_read);
-#ifdef HAVE_SSL
-               }
+      if (rbuf->ssl!=NULL)
+       res = ssl_iread (rbuf->ssl, c, amount_to_read);
+      else
 #endif /* HAVE_SSL */
+       res = iread (fd, c, amount_to_read);
+
       if (res > 0)
        {
          fwrite (c, sizeof (char), res, fp);
@@ -141,8 +187,19 @@ get_contents (int fd, FILE *fp, long *len, long restval, long expected,
              res = -2;
              goto out;
            }
+
+         /* If bandwidth is not limited, one call to wtimer_elapsed
+            is sufficient.  */
+         dltime = wtimer_elapsed (timer);
+         if (opt.limit_rate)
+           {
+             limit_bandwidth (res, dltime - last_dltime);
+             dltime = wtimer_elapsed (timer);
+             last_dltime = dltime;
+           }
+
          if (opt.verbose)
-           progress_update (progress, res, wtimer_elapsed (timer));
+           progress_update (progress, res, dltime);
          *len += res;
        }
       else
@@ -152,15 +209,12 @@ get_contents (int fd, FILE *fp, long *len, long restval, long expected,
     res = -1;
 
  out:
-  if (timer)
-    {
-      long dltime = wtimer_elapsed (timer);
-      if (opt.verbose)
-       progress_finish (progress, dltime);
-      if (elapsed)
-       *elapsed = dltime;
-      wtimer_delete (timer);
-    }
+  if (opt.verbose)
+    progress_finish (progress, dltime);
+  if (elapsed)
+    *elapsed = dltime;
+  wtimer_delete (timer);
+
   return res;
 }
 \f