Bandwidth limit access filter

configure.ac

@@ -1175,6 +1175,7 @@ VLC_ADD_PLUGINS([i420_rgb rawvideo blend scale image logo magnify puzzle colorth
 VLC_ADD_PLUGINS([wav araw subtitle vobsub adpcm a52sys dtssys au ty voc xa nuv])
 VLC_ADD_PLUGINS([access_directory access_file access_udp access_tcp])
 VLC_ADD_PLUGINS([access_http access_mms access_ftp])
+VLC_ADD_PLUGINS([access_filter_bandwidth])
 VLC_ADD_PLUGINS([packetizer_mpegvideo packetizer_h264])
 VLC_ADD_PLUGINS([packetizer_mpeg4video packetizer_mpeg4audio])
 VLC_ADD_PLUGINS([packetizer_vc1])

modules/access_filter/Modules.am

 SOURCES_access_filter_timeshift = timeshift.c
 SOURCES_access_filter_record = record.c
 SOURCES_access_filter_dump = dump.c
+SOURCES_access_filter_bandwidth = bandwidth.c

modules/access_filter/bandwidth.c

+/*****************************************************************************
+ * bandwidth.c
+ *****************************************************************************
+ * Copyright © 2007 Rémi Denis-Courmont
+ * $Id: dump.c 19948 2007-04-26 19:53:53Z courmisch $
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#include <vlc/vlc.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <vlc_access.h>
+
+#define BANDWIDTH_TEXT N_("Bandwidth limit (bytes/s)")
+#define BANDWIDTH_LONGTEXT N_( \
+    "The bandwidth module will drop any data in excess of that many bytes " \
+    "per seconds." )
+
+static int  Open (vlc_object_t *);
+static void Close (vlc_object_t *);
+
+/* TODO: burst support */
+
+vlc_module_begin ();
+    set_shortname (_("Bandwidth"));
+    set_description (_("Bandwidth limiter"));
+    set_category (CAT_INPUT);
+    set_subcategory (SUBCAT_INPUT_ACCESS_FILTER);
+    set_capability ("access_filter", 0);
+    add_shortcut ("bandwidth");
+    set_callbacks (Open, Close);
+
+    add_integer ("access-bandwidth", 65536, NULL, BANDWIDTH_TEXT,
+                 BANDWIDTH_LONGTEXT, VLC_FALSE);
+vlc_module_end();
+
+static int Read (access_t *access, uint8_t *buffer, int len);
+static int Seek (access_t *access, int64_t offset);
+static int Control (access_t *access, int cmd, va_list ap);
+
+struct access_sys_t
+{
+    mtime_t last_time;
+    size_t  last_size;
+    size_t  bandwidth;
+};
+
+/**
+ * Open()
+ */
+static int Open (vlc_object_t *obj)
+{
+    access_t *access = (access_t*)obj;
+    access_t *src = access->p_source;
+
+    if (src->pf_read != NULL)
+        access->pf_read = Read;
+    else
+    {
+        msg_Err (obj, "block bandwidth limit not implemented");
+        return VLC_EGENERIC;
+    }
+
+    if (src->pf_seek != NULL)
+        access->pf_seek = Seek;
+
+    access->pf_control = Control;
+    access->info = src->info;
+
+    access_sys_t *p_sys = access->p_sys = malloc (sizeof (*p_sys));
+    if (p_sys == NULL)
+        return VLC_ENOMEM;
+
+    memset (p_sys, 0, sizeof (*p_sys));
+    p_sys->bandwidth = var_CreateGetInteger (access, "access-bandwidth");
+    p_sys->last_time = mdate ();
+
+    msg_Dbg (obj, "bandwidth limit: %u bytes/s", p_sys->bandwidth);
+    return VLC_SUCCESS;
+}
+
+
+/**
+ * Close()
+ */
+static void Close (vlc_object_t *obj)
+{
+    access_t *access = (access_t *)obj;
+    access_sys_t *p_sys = access->p_sys;
+    free (p_sys);
+}
+
+
+static int Read (access_t *access, uint8_t *buffer, int len)
+{
+    access_t *src = access->p_source;
+    access_sys_t *p_sys = access->p_sys;
+    mtime_t now;
+
+    if (len == 0)
+        return 0;
+
+retry:
+    now = mdate ();
+    if (now <= p_sys->last_time)
+    {
+        msg_Err (access, "*** ALERT *** System clock is going backward! ***");
+        return 0; /* Uho, your clock is broken. */
+    }
+
+    mtime_t delta = now - p_sys->last_time;
+    p_sys->last_time = now;
+
+    delta *= p_sys->bandwidth;
+    delta /= 1000000u;
+
+    if (delta == 0)
+    {
+        now += 1000000u / p_sys->bandwidth;
+        mwait (now);
+        goto retry;
+    }
+
+    if (len > delta)
+    {
+        msg_Dbg (access, "reading %u bytes instead of %u", (unsigned)delta,
+                 len);
+        len = (int)delta;
+    }
+
+
+    src->info.i_update = access->info.i_update;
+    len = src->pf_read (src, buffer, len);
+    access->info = src->info;
+
+    msg_Dbg (access, "read %u bytes", len);
+    return len;
+}
+
+
+static int Control (access_t *access, int cmd, va_list ap)
+{
+    access_t *src = access->p_source;
+    return src->pf_control (src, cmd, ap);
+}
+
+
+static int Seek (access_t *access, int64_t offset)
+{
+    access_t *src = access->p_source;
+
+    src->info.i_update = access->info.i_update;
+    int ret = src->pf_seek (src, offset);
+    access->info = src->info;
+    return ret;
+}