Rewrite chunk queueing.
authorAndre Noll <maan@systemlinux.org>
Wed, 8 Aug 2007 22:00:45 +0000 (00:00 +0200)
committerAndre Noll <maan@systemlinux.org>
Wed, 8 Aug 2007 22:00:45 +0000 (00:00 +0200)
Since paraslash-0.2.16 the audio file is mmapped, so it is no longer neccessary
to make a copy of the chunk data in case a chunk can not be sent immediately
because the write would block. Just remember the chunk number and the number of
bytes of that chunk which were sent (non-zero in case of short writes).

The chunk data can then be retrieved by the new vss_get_chunk() function.

error.h
http_send.c
vss.c
vss.h

diff --git a/error.h b/error.h
index d82fe68..ffb3eed 100644 (file)
--- a/error.h
+++ b/error.h
@@ -275,6 +275,7 @@ extern const char **para_errlist[];
 
 #define VSS_ERRORS \
        PARA_ERROR(AUDIO_FORMAT, "audio format not recognized"), \
+       PARA_ERROR(CHUNK, "unable to get chunk"), \
 
 
 #define AFS_ERRORS \
index d09306b..414c375 100644 (file)
@@ -63,25 +63,25 @@ struct http_client {
        int check_w;
        /** The position of this client in the client list. */
        struct list_head node;
-       /** Te list of pending packets for this client. */
-       struct list_head packet_queue;
+       /** The list of pending chunks for this client. */
+       struct list_head chunk_queue;
        /** The number of pending bytes for this client. */
-       unsigned long pq_bytes;
+       unsigned long cq_bytes;
 };
 
 /**
- * Describes one queued data packet for a client.
+ * Describes one queued chunk of the chunk queue.
  *
  * The send function of the http sender checks each client fd for writing. If a
- * client fd is not ready, it tries to queue that packet for this client until
+ * client fd is not ready, it tries to queue that chunk for this client until
  * the number of queued bytes exceeds \p MAX_BACKLOG.
  */
-struct queued_packet {
-       /** The length of the packet in bytes. */
-       unsigned int len;
-       /** Pointer to the packet data. */
-       char *packet;
-       /** Position of the packet in the packet list. */
+struct queued_chunk {
+       /** The number of the queued chunk, -1U means header. */
+       unsigned chunk_num;
+       /** The number of bytes already sent. */
+       unsigned sent;
+       /** Position of the chunk in the chunk queue. */
        struct list_head node;
 };
 
@@ -102,16 +102,15 @@ static struct sender *self;
 
 static void http_shutdown_client(struct http_client *hc, const char *msg)
 {
-       struct queued_packet *qp, *tmp;
+       struct queued_chunk *qc, *tmp;
        PARA_INFO_LOG("shutting down %s on fd %d (%s)\n", CLIENT_ADDR(hc),
                hc->fd, msg);
        numclients--;
        close(hc->fd);
        del_close_on_fork_list(hc->fd);
-       list_for_each_entry_safe(qp, tmp, &hc->packet_queue, node) {
-               free(qp->packet);
-               list_del(&qp->node);
-               free(qp);
+       list_for_each_entry_safe(qc, tmp, &hc->chunk_queue, node) {
+               list_del(&qc->node);
+               free(qc);
        }
        list_del(&hc->node);
        free(hc);
@@ -145,50 +144,74 @@ static int http_send_err_msg(struct http_client *hc)
        return http_send_msg(hc, HTTP_ERR_MSG);
 }
 
-static int queue_packet(struct http_client *hc, const char *buf, size_t len)
+static int queue_chunk(struct http_client *hc, long unsigned chunk_num,
+       size_t sent)
 {
-       struct queued_packet *qp;
-       if (hc->pq_bytes + len > MAX_BACKLOG) {
-               http_shutdown_client(hc, "packet queue overrun");
+       struct queued_chunk *qc;
+       char *buf;
+       size_t len;
+       int ret;
+
+       if (chunk_num != -1U) {
+               ret = vss_get_chunk(chunk_num, &buf, &len);
+               if (ret < 0)
+                       return ret;
+       } else
+               buf = vss_get_header(&len);
+       if (hc->cq_bytes + len > MAX_BACKLOG)
                return -E_QUEUE;
-       }
-       qp = para_malloc(sizeof(struct queued_packet));
-       hc->pq_bytes += len;
-       qp->packet = para_malloc(len);
-       memcpy(qp->packet, buf, len);
-       qp->len = len;
-       list_add_tail(&qp->node, &hc->packet_queue);
-       PARA_INFO_LOG("%lu bytes queued for fd %d\n", hc->pq_bytes, hc->fd);
+       qc = para_malloc(sizeof(struct queued_chunk));
+       hc->cq_bytes += len;
+       qc->chunk_num = chunk_num;
+       qc->sent = sent;
+       list_add_tail(&qc->node, &hc->chunk_queue);
+       PARA_INFO_LOG("%lu bytes queued for fd %d\n", hc->cq_bytes, hc->fd);
        return 1;
 }
 
-static int send_queued_packets(struct http_client *hc)
+static int send_queued_chunks(struct http_client *hc)
 {
        int ret;
-       struct queued_packet *qp, *tmp;
+       struct queued_chunk *qc, *tmp;
 
-       if (list_empty(&hc->packet_queue))
+       if (list_empty(&hc->chunk_queue))
                return 1;
-       list_for_each_entry_safe(qp, tmp, &hc->packet_queue, node) {
+       list_for_each_entry_safe(qc, tmp, &hc->chunk_queue, node) {
+               char *buf;
+               size_t len;
                ret = write_ok(hc->fd);
                if (ret <= 0)
                        return ret? -E_WRITE_OK : 0;
-               ret = write(hc->fd, qp->packet, qp->len);
+               if (qc->chunk_num != -1U) {
+                       ret = vss_get_chunk(qc->chunk_num, &buf, &len);
+                       if (ret < 0)
+                               return ret;
+               } else
+                       buf = vss_get_header(&len);
+               assert(len && len > qc->sent);
+               ret = write(hc->fd, buf + qc->sent, len - qc->sent);
                if (ret < 0)
-                       return ret;
-               if (ret != qp->len) {
-                       qp->len -= ret;
-                       memmove(qp->packet, qp->packet + ret, qp->len);
+                       return -1; /* FIXME */
+               hc->cq_bytes -= ret;
+               if (ret != len - qc->sent) {
+                       qc->sent += ret;
                        return 0;
                }
-               hc->pq_bytes -= qp->len;
-               free(qp->packet);
-               list_del(&qp->node);
-               free(qp);
+               list_del(&qc->node);
+               free(qc);
        }
        return 1;
 }
 
+static int queue_chunk_or_shutdown(struct http_client *hc, long unsigned chunk_num,
+       size_t sent)
+{
+       int ret = queue_chunk(hc, chunk_num, sent);
+       if (ret < 0)
+               http_shutdown_client(hc, "queue error");
+       return ret;
+}
+
 static void http_send( long unsigned current_chunk,
        __a_unused long unsigned chunks_sent, const char *buf, size_t len)
 {
@@ -205,34 +228,35 @@ static void http_send( long unsigned current_chunk,
                        if (hbuf && hlen > 0 && current_chunk) {
                                /* need to send header */
                                PARA_INFO_LOG("queueing header: %d\n", hlen);
-                               if (queue_packet(hc, hbuf, hlen) < 0)
+                               if (queue_chunk_or_shutdown(hc, -1U, 0) < 0)
                                        continue;
                        } else
-                               PARA_INFO_LOG("%s", "no need to queue header\n");
+                               PARA_INFO_LOG("no need to queue header\n");
                        hc->status = HTTP_STREAMING;
                }
-               ret = send_queued_packets(hc);
+               ret = send_queued_chunks(hc);
                if (ret < 0) {
-                       http_shutdown_client(hc, "send error");
+                       http_shutdown_client(hc, "queue send error");
                        continue;
                }
                if (!len)
                        continue;
                if (!ret || write_ok(hc->fd) <= 0) {
                        PARA_INFO_LOG("fd %d not ready (%lu bytes queued),"
-                               " trying to queue packet\n", hc->fd,
-                               hc->pq_bytes);
-                       queue_packet(hc, buf, len);
+                               " trying to queue chunk\n", hc->fd,
+                               hc->cq_bytes);
+                       queue_chunk_or_shutdown(hc, current_chunk, 0);
                        continue;
                }
 //             PARA_DEBUG_LOG("sending %d -> %s\n", len, CLIENT_ADDR(hc));
                ret = write(hc->fd, buf, len);
+//             PARA_DEBUG_LOG("ret: %d\n", ret);
                if (ret < 0) {
                        http_shutdown_client(hc, "send error");
                        continue;
                }
                if (ret != len)
-                       queue_packet(hc, buf + ret, len - ret);
+                       queue_chunk_or_shutdown(hc, current_chunk, ret);
        }
 }
 
@@ -312,7 +336,7 @@ static void http_post_select(fd_set *rfds, fd_set *wfds)
                goto err_out;
        }
        hc->status = HTTP_CONNECTED;
-       INIT_LIST_HEAD(&hc->packet_queue);
+       INIT_LIST_HEAD(&hc->chunk_queue);
        PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", numclients,
                CLIENT_ADDR(hc), hc->fd);
        numclients++;
diff --git a/vss.c b/vss.c
index 7892fb1..a16b006 100644 (file)
--- a/vss.c
+++ b/vss.c
@@ -495,6 +495,32 @@ again:
        return ret;
 }
 
+static void get_chunk(long unsigned chunk_num, char **buf, size_t *len)
+{
+       size_t pos = mmd->afi.chunk_table[chunk_num];
+       *buf = map + pos;
+       *len = mmd->afi.chunk_table[chunk_num + 1] - pos;
+}
+
+/**
+ * Get the data of the given chunk.
+ *
+ * \param chunk_num The number of the desired chunk.
+ * \param buf Chunk data.
+ * \param len Chunk length in bytes.
+ *
+ * \return Positive on success, negative on errors.
+ */
+int vss_get_chunk(long unsigned chunk_num, char **buf, size_t *len)
+{
+       if (mmd->audio_format < 0 || !map || !vss_playing())
+               return -E_CHUNK;
+       if (chunk_num >= mmd->afi.chunks_total)
+               return -E_CHUNK;
+       get_chunk(chunk_num, buf, len);
+       return 1;
+}
+
 /**
  * main sending function
  *
@@ -508,8 +534,6 @@ void vss_send_chunk(void)
 {
        int i;
        struct audio_format_handler *af;
-       ssize_t pos;
-       size_t len;
        struct timeval now, due;
 
        if (mmd->audio_format < 0 || !map || !vss_playing())
@@ -529,8 +553,6 @@ void vss_send_chunk(void)
                mmd->new_vss_status_flags |= VSS_NEXT;
                return vss_eof();
        }
-       pos = mmd->afi.chunk_table[mmd->current_chunk];
-       len = mmd->afi.chunk_table[mmd->current_chunk + 1] - pos;
        /*
         * We call the send function also in case of empty chunks as they
         * might have still some data queued which can be sent in this case.
@@ -542,9 +564,12 @@ void vss_send_chunk(void)
                mmd->offset = tv2ms(&tmp);
                mmd->events++;
        }
-       for (i = 0; senders[i].name; i++)
-               senders[i].send(mmd->current_chunk, mmd->chunks_sent,
-                       map + pos, len);
+       for (i = 0; senders[i].name; i++) {
+               char *buf;
+               size_t len;
+               get_chunk(mmd->current_chunk, &buf, &len);
+               senders[i].send(mmd->current_chunk, mmd->chunks_sent, buf, len);
+       }
        mmd->new_vss_status_flags |= VSS_PLAYING;
        mmd->chunks_sent++;
        mmd->current_chunk++;
diff --git a/vss.h b/vss.h
index ffab5cc..bd3b4d7 100644 (file)
--- a/vss.h
+++ b/vss.h
@@ -17,6 +17,7 @@ char *vss_get_header(unsigned *header_len);
 struct timeval *vss_chunk_time(void);
 int guess_audio_format(const char *name);
 const char *supported_audio_formats(void);
+int vss_get_chunk(long unsigned chunk_num, char **buf, size_t *len);
 
 /** stop playing after current audio file */
 #define VSS_NOMORE 1