for bug #241, calc the small and sleep for merged read.

@@ -27,13 +27,21 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_protocol_stack.hpp>
 #include <srs_app_rtmp_conn.hpp>
 #include <srs_protocol_buffer.hpp>
+#include <srs_kernel_utility.hpp>
 
 // when we read from socket less than this value,
 // sleep a while to merge read.
 // @see https://github.com/winlinvip/simple-rtmp-server/issues/241
-#define SRS_MERGED_READ_SIZE(buffer) (buffer / 10)
-// the time to sleep to merge read, to read more bytes.
-#define SRS_MERGED_READ_US (300 * 1000)
+// use the bitrate in kbps to calc the max sleep time.
+#define SRS_MR_MAX_BITRATE_KBPS 10000
+#define SRS_MR_AVERAGE_BITRATE_KBPS 1000
+#define SRS_MR_MIN_BITRATE_KBPS 64
+// the max sleep time in ms
+#define SRS_MR_MAX_SLEEP_MS 3000
+// the max small bytes to group
+#define SRS_MR_SMALL_BYTES 64
+// the percent of buffer to set as small bytes
+#define SRS_MR_SMALL_PERCENT 100
 
 ISrsMessageHandler::ISrsMessageHandler()
 {
@@ -226,7 +234,7 @@ void SrsQueueRecvThread::on_thread_stop()
 }
 
 SrsPublishRecvThread::SrsPublishRecvThread(
-    SrsRtmpServer* rtmp_sdk, int timeout_ms,
+    SrsRtmpServer* rtmp_sdk, int fd, int timeout_ms,
     SrsRtmpConn* conn, SrsSource* source, bool is_fmle, bool is_edge
 ): trd(this, rtmp_sdk, timeout_ms)
 {
@@ -239,6 +247,10 @@ SrsPublishRecvThread::SrsPublishRecvThread(
     recv_error_code = ERROR_SUCCESS;
     _nb_msgs = 0;
     error = st_cond_new();
+
+    mr_fd = fd;
+    mr_small_bytes = 0;
+    mr_sleep_ms = 0;
 }
 
 SrsPublishRecvThread::~SrsPublishRecvThread()
@@ -284,9 +296,17 @@ void SrsPublishRecvThread::on_thread_start()
     // we donot set the auto response to false,
     // for the main thread never send message.
 
+    // 128KB recv buffer.
+    int nb_rbuf = 128 * 1024;
+    socklen_t sock_buf_size = sizeof(int);
+    if (setsockopt(mr_fd, SOL_SOCKET, SO_RCVBUF, &nb_rbuf, sock_buf_size) < 0) {
+        srs_warn("set sock SO_RCVBUF=%d failed.", nb_rbuf);
+    }
+    getsockopt(mr_fd, SOL_SOCKET, SO_RCVBUF, &nb_rbuf, &sock_buf_size);
+
     // enable the merge read
     // @see https://github.com/winlinvip/simple-rtmp-server/issues/241
-    rtmp->set_merge_read(true, this);
+    rtmp->set_merge_read(true, nb_rbuf, this);
 }
 
 void SrsPublishRecvThread::on_thread_stop()
@@ -300,7 +320,7 @@ void SrsPublishRecvThread::on_thread_stop()
 
     // disable the merge read
     // @see https://github.com/winlinvip/simple-rtmp-server/issues/241
-    rtmp->set_merge_read(false, NULL);
+    rtmp->set_merge_read(false, 0, NULL);
 }
 
 bool SrsPublishRecvThread::can_handle()
@@ -334,9 +354,9 @@ void SrsPublishRecvThread::on_recv_error(int ret)
     st_cond_signal(error);
 }
 
-void SrsPublishRecvThread::on_read(int nb_buffer, ssize_t nread)
+void SrsPublishRecvThread::on_read(ssize_t nread)
 {
-    if (nread < 0) {
+    if (nread < 0 || mr_sleep_ms <= 0) {
         return;
     }
     
@@ -346,7 +366,31 @@ void SrsPublishRecvThread::on_read(int nb_buffer, ssize_t nread)
     * that is, we merge some data to read together.
     * @see https://github.com/winlinvip/simple-rtmp-server/issues/241
     */
-    if (nread < SRS_MERGED_READ_SIZE(nb_buffer)) {
-        st_usleep(SRS_MERGED_READ_US);
+    if (nread < mr_small_bytes) {
+        st_usleep(mr_sleep_ms * 1000);
     }
 }
+
+void SrsPublishRecvThread::on_buffer_change(int nb_buffer)
+{
+    // set percent.
+    mr_small_bytes = (int)(nb_buffer / SRS_MR_SMALL_PERCENT);
+    // select the smaller
+    mr_small_bytes = srs_min(mr_small_bytes, SRS_MR_SMALL_BYTES);
+
+    // the recv sleep is [buffer / max_kbps, buffer / min_kbps]
+    // for example, buffer is 256KB, max kbps is 10Mbps, min kbps is 10Kbps,
+    // the buffer is 256KB*8=2048Kb, which can provides sleep time in
+    //      min: 2038Kb/10Mbps=2038Kb/10Kbpms=203.8ms
+    //      max: 2038Kb/10Kbps=203.8s
+    // sleep = Xb * 8 / (N * 1000 b / 1000 ms) = (X * 8 / N) ms
+    // @see https://github.com/winlinvip/simple-rtmp-server/issues/241
+    int min_sleep = (int)(nb_buffer * 8.0 / SRS_MR_MAX_BITRATE_KBPS);
+    int average_sleep = (int)(nb_buffer * 8.0 / SRS_MR_AVERAGE_BITRATE_KBPS);
+    int max_sleep = (int)(nb_buffer * 8.0 / SRS_MR_MIN_BITRATE_KBPS);
+    // 80% min, 16% average, 4% max.
+    mr_sleep_ms = (int)(min_sleep * 0.8 + average_sleep * 0.16 + max_sleep * 0.04);
+    mr_sleep_ms = srs_min(mr_sleep_ms, SRS_MR_MAX_SLEEP_MS);
+
+    srs_trace("merged read, buffer=%d, small=%d, sleep=%d", nb_buffer, mr_small_bytes, mr_sleep_ms);
+}

@@ -140,6 +140,11 @@ private:
     SrsRtmpServer* rtmp;
     // the msgs already got.
     int64_t _nb_msgs;
+    // for mr(merged read),
+    // @see https://github.com/winlinvip/simple-rtmp-server/issues/241
+    int mr_fd;
+    int mr_small_bytes;
+    int mr_sleep_ms;
     // the recv thread error code.
     int recv_error_code;
     SrsRtmpConn* _conn;
@@ -151,7 +156,7 @@ private:
     // @see https://github.com/winlinvip/simple-rtmp-server/issues/244
     st_cond_t error;
 public:
-    SrsPublishRecvThread(SrsRtmpServer* rtmp_sdk, int timeout_ms,
+    SrsPublishRecvThread(SrsRtmpServer* rtmp_sdk, int fd, int timeout_ms,
         SrsRtmpConn* conn, SrsSource* source, bool is_fmle, bool is_edge);
     virtual ~SrsPublishRecvThread();
 public:
@@ -173,7 +178,8 @@ public:
     virtual void on_recv_error(int ret);
 // interface IMergeReadHandler
 public:
-    virtual void on_read(int nb_buffer, ssize_t nread);
+    virtual void on_read(ssize_t nread);
+    virtual void on_buffer_change(int nb_buffer);
 };
 
 #endif

@@ -659,7 +659,7 @@ int SrsRtmpConn::fmle_publishing(SrsSource* source)
 
     // use isolate thread to recv,
     // @see: https://github.com/winlinvip/simple-rtmp-server/issues/237
-    SrsPublishRecvThread trd(rtmp, 
+    SrsPublishRecvThread trd(rtmp, st_netfd_fileno(stfd),
         SRS_CONSTS_RTMP_RECV_TIMEOUT_US / 1000, 
         this, source, true, vhost_is_edge);
 
@@ -695,7 +695,7 @@ int SrsRtmpConn::flash_publishing(SrsSource* source)
 
     // use isolate thread to recv,
     // @see: https://github.com/winlinvip/simple-rtmp-server/issues/237
-    SrsPublishRecvThread trd(rtmp, 
+    SrsPublishRecvThread trd(rtmp, st_netfd_fileno(stfd),
         SRS_CONSTS_RTMP_RECV_TIMEOUT_US / 1000, 
         this, source, false, vhost_is_edge);
 

@@ -112,7 +112,7 @@ int SrsBuffer::grow(ISrsBufferReader* reader, int required_size)
         * @see https://github.com/winlinvip/simple-rtmp-server/issues/241
         */
         if (merged_read && _handler) {
-            _handler->on_read(nb_buffer, nread);
+            _handler->on_read(nread);
         }
         
         srs_assert((int)nread > 0);
@@ -122,10 +122,14 @@ int SrsBuffer::grow(ISrsBufferReader* reader, int required_size)
     return ret;
 }
 
-void SrsBuffer::set_merge_read(bool v, IMergeReadHandler* handler)
+void SrsBuffer::set_merge_read(bool v, int max_buffer, IMergeReadHandler* handler)
 {
     merged_read = v;
     _handler = handler;
+
+    if (v && max_buffer != nb_buffer) {
+        reset_buffer(max_buffer);
+    }
 }
 
 void SrsBuffer::on_chunk_size(int32_t chunk_size)
@@ -134,10 +138,7 @@ void SrsBuffer::on_chunk_size(int32_t chunk_size)
         return;
     }
 
-    srs_freep(buffer);
-
-    nb_buffer = chunk_size;
-    buffer = new char[nb_buffer];
+    reset_buffer(chunk_size);
 }
 
 int SrsBuffer::buffer_size()
@@ -145,4 +146,14 @@ int SrsBuffer::buffer_size()
     return nb_buffer;
 }
 
+void SrsBuffer::reset_buffer(int size)
+{
+    srs_freep(buffer);
+
+    nb_buffer = size;
+    buffer = new char[nb_buffer];
 
+    if (_handler) {
+        _handler->on_buffer_change(nb_buffer);
+    }
+}

@@ -51,7 +51,12 @@ public:
     * some small bytes.
     * @remark, it only for server-side, client srs-librtmp just ignore.
     */
-    virtual void on_read(int nb_buffer, ssize_t nread) = 0;
+    virtual void on_read(ssize_t nread) = 0;
+    /**
+    * when buffer size changed.
+    * @param nb_buffer the new buffer size.
+    */
+    virtual void on_buffer_change(int nb_buffer) = 0;
 };
 
 /**
@@ -110,11 +115,11 @@ public:
     * when it on and read small bytes, we sleep to wait more data.,
     * that is, we merge some data to read together.
     * @param v true to ename merged read.
+    * @param max_buffer the max buffer size, the socket buffer.
     * @param handler the handler when merge read is enabled.
     * @see https://github.com/winlinvip/simple-rtmp-server/issues/241
     */
-    virtual void set_merge_read(bool v, IMergeReadHandler* handler);
-public:
+    virtual void set_merge_read(bool v, int max_buffer, IMergeReadHandler* handler);
     /**
     * when chunk size changed, the buffer should change the buffer also.
     * to keep the socket buffer size always greater than chunk size.
@@ -125,6 +130,8 @@ public:
     * get the size of socket buffer to read.
     */
     virtual int buffer_size();
+private:
+    virtual void reset_buffer(int size);
 };
 
 #endif

@@ -745,9 +745,9 @@ void SrsRtmpServer::set_auto_response(bool v)
     protocol->set_auto_response(v);
 }
 
-void SrsRtmpServer::set_merge_read(bool v, IMergeReadHandler* handler)
+void SrsRtmpServer::set_merge_read(bool v, int max_buffer, IMergeReadHandler* handler)
 {
-    protocol->set_merge_read(v, handler);
+    protocol->set_merge_read(v, max_buffer, handler);
 }
 
 void SrsRtmpServer::set_recv_timeout(int64_t timeout_us)

@@ -348,10 +348,11 @@ public:
     * when it on and read small bytes, we sleep to wait more data.,
     * that is, we merge some data to read together.
     * @param v true to ename merged read.
+    * @param max_buffer the max buffer size, the socket buffer.
     * @param handler the handler when merge read is enabled.
     * @see https://github.com/winlinvip/simple-rtmp-server/issues/241
     */
-    virtual void set_merge_read(bool v, IMergeReadHandler* handler);
+    virtual void set_merge_read(bool v, int max_buffer, IMergeReadHandler* handler);
     /**
     * set/get the recv timeout in us.
     * if timeout, recv/send message return ERROR_SOCKET_TIMEOUT.

@@ -479,9 +479,9 @@ int SrsProtocol::manual_response_flush()
     return ret;
 }
 
-void SrsProtocol::set_merge_read(bool v, IMergeReadHandler* handler)
+void SrsProtocol::set_merge_read(bool v, int max_buffer, IMergeReadHandler* handler)
 {
-    in_buffer->set_merge_read(v, handler);
+    in_buffer->set_merge_read(v, max_buffer, handler);
 }
 
 void SrsProtocol::set_recv_timeout(int64_t timeout_us)

@@ -276,10 +276,11 @@ public:
     * when it on and read small bytes, we sleep to wait more data.,
     * that is, we merge some data to read together.
     * @param v true to ename merged read.
+    * @param max_buffer the max buffer size, the socket buffer.
     * @param handler the handler when merge read is enabled.
     * @see https://github.com/winlinvip/simple-rtmp-server/issues/241
     */
-    virtual void set_merge_read(bool v, IMergeReadHandler* handler);
+    virtual void set_merge_read(bool v, int max_buffer, IMergeReadHandler* handler);
 public:
     /**
     * set/get the recv timeout in us.