for bug #241, simplify the merged read config macros.

@@ -736,7 +736,7 @@ The publish benchmark by [st-load](https://github.com/winlinvip/st-load):
 * 2014-12-03, SRS 2.0.48,  1.4k(1400) publishers, 95%CPU, 140MB. [commit](https://github.com/winlinvip/simple-rtmp-server/commit/f35ec2155b1408d528a9f37da7904c9625186bcf)
 * 2014-12-04, SRS 2.0.49,  1.4k(1400) publishers, 68%CPU, 144MB.
 * 2014-12-04, SRS 2.0.49,  2.5k(2500) publishers, 95%CPU, 404MB. [commit](https://github.com/winlinvip/simple-rtmp-server/commit/29324fab469e0f7cef9ad04ffdbce832ac7dd9ff)
-* 2014-12-04, SRS 2.0.51,  2.5k(2500) publishers, 92%CPU, 259MB. [commit](https://github.com/winlinvip/simple-rtmp-server/commit/f57801eb46c16755b173984b915a4166922df6a6)
+* 2014-12-04, SRS 2.0.51,  2.5k(2500) publishers, 91%CPU, 259MB. [commit](https://github.com/winlinvip/simple-rtmp-server/commit/f57801eb46c16755b173984b915a4166922df6a6)
 
 ## Architecture
 

@@ -30,23 +30,6 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_kernel_utility.hpp>
 #include <srs_core_performance.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
-// 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 32
-// the max sleep time in ms
-#define SRS_MR_MAX_SLEEP_MS 2500
-// the max small bytes to group
-#define SRS_MR_SMALL_BYTES 4096
-// the percent of buffer to set as small bytes
-#define SRS_MR_SMALL_PERCENT 100
-// set the socket buffer to specified bytes.
-// the underlayer api will set to SRS_MR_SOCKET_BUFFER bytes.
-#define SRS_MR_SOCKET_BUFFER SOCKET_READ_SIZE
-
 ISrsMessageHandler::ISrsMessageHandler()
 {
 }
@@ -253,8 +236,6 @@ SrsPublishRecvThread::SrsPublishRecvThread(
     error = st_cond_new();
 
     mr_fd = fd;
-    mr_small_bytes = 0;
-    mr_sleep_ms = 0;
 }
 
 SrsPublishRecvThread::~SrsPublishRecvThread()
@@ -309,7 +290,8 @@ void SrsPublishRecvThread::on_thread_start()
     }
     getsockopt(mr_fd, SOL_SOCKET, SO_RCVBUF, &nb_rbuf, &sock_buf_size);
 
-    srs_trace("set socket buffer to %d, actual %d KB", SRS_MR_SOCKET_BUFFER / 1024, nb_rbuf / 1024);
+    srs_trace("merged read sockbuf=%d, actual=%d, sleep %d when nread<=%d", 
+        SRS_MR_SOCKET_BUFFER, nb_rbuf, SRS_MR_MAX_SLEEP_MS, SRS_MR_SMALL_BYTES);
 
     // enable the merge read
     // @see https://github.com/winlinvip/simple-rtmp-server/issues/241
@@ -367,7 +349,7 @@ void SrsPublishRecvThread::on_recv_error(int ret)
 #ifdef SRS_PERF_MERGED_READ
 void SrsPublishRecvThread::on_read(ssize_t nread)
 {
-    if (nread < 0 || mr_sleep_ms <= 0) {
+    if (nread < 0 || SRS_MR_MAX_SLEEP_MS <= 0) {
         return;
     }
     
@@ -377,34 +359,8 @@ void SrsPublishRecvThread::on_read(ssize_t nread)
     * that is, we merge some data to read together.
     * @see https://github.com/winlinvip/simple-rtmp-server/issues/241
     */
-    if (nread < mr_small_bytes) {
-        st_usleep(mr_sleep_ms * 1000);
+    if (nread < SRS_MR_SMALL_BYTES) {
+        st_usleep(SRS_MR_MAX_SLEEP_MS * 1000);
     }
 }
-
-void SrsPublishRecvThread::on_buffer_change(int nb_buffer)
-{
-    srs_assert(nb_buffer > 0);
-    
-    // set percent.
-    mr_small_bytes = (int)(nb_buffer / SRS_MR_SMALL_PERCENT);
-    // select the smaller
-    mr_small_bytes = srs_max(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);
-}
 #endif

@@ -147,8 +147,6 @@ private:
     // 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;
@@ -184,7 +182,6 @@ public:
 public:
 #ifdef SRS_PERF_MERGED_READ
     virtual void on_read(ssize_t nread);
-    virtual void on_buffer_change(int nb_buffer);
 #endif
 };
 

@@ -64,8 +64,17 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *       buffer=65536B, small=4096B, sleep=780ms
 *       that is, when got nread bytes smaller than 4KB, sleep(780ms).
 */
-#undef SRS_PERF_MERGED_READ
-#define SRS_PERF_MERGED_READ
+#if 1
+    // to enable merged read.
+    #define SRS_PERF_MERGED_READ
+    // the max sleep time in ms
+    #define SRS_MR_MAX_SLEEP_MS 1000
+    // the max small bytes to group
+    #define SRS_MR_SMALL_BYTES 4096
+    // the underlayer api will set to SRS_MR_SOCKET_BUFFER bytes.
+    // 4KB=4096, 8KB=8192, 16KB=16384, 32KB=32768, 64KB=65536
+    #define SRS_MR_SOCKET_BUFFER 65536
+#endif
 
 /**
 * the send cache time in ms.

@@ -93,7 +93,7 @@ SrsFastBuffer::SrsFastBuffer()
     p = end = buffer = NULL;
     nb_buffer = 0;
     
-    reset_buffer(SOCKET_READ_SIZE);
+    reset_buffer(SRS_MR_SOCKET_BUFFER);
 }
 
 SrsFastBuffer::~SrsFastBuffer()
@@ -192,15 +192,11 @@ void SrsFastBuffer::set_merge_read(bool v, int max_buffer, IMergeReadHandler* ha
     _handler = handler;
 
     // limit the max buffer.
-    int buffer_size = srs_min(max_buffer, SOCKET_MAX_BUF);
+    int buffer_size = srs_min(max_buffer, SRS_MR_SOCKET_BUFFER);
 
     if (v && buffer_size != nb_buffer) {
         reset_buffer(buffer_size);
     }
-
-    if (_handler) {
-        _handler->on_buffer_change(nb_buffer);
-    }
 }
 #endif
 
@@ -211,17 +207,11 @@ void SrsFastBuffer::on_chunk_size(int32_t chunk_size)
     }
 
     // limit the max buffer.
-    int buffer_size = srs_min(chunk_size, SOCKET_MAX_BUF);
+    int buffer_size = srs_min(chunk_size, SRS_MR_SOCKET_BUFFER);
 
     if (buffer_size != nb_buffer) {
         reset_buffer(buffer_size);
     }
-
-#ifdef SRS_PERF_MERGED_READ
-    if (_handler) {
-        _handler->on_buffer_change(nb_buffer);
-    }
-#endif
 }
 
 int SrsFastBuffer::buffer_size()

@@ -35,16 +35,6 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_protocol_io.hpp>
 #include <srs_core_performance.hpp>
 
-// 4KB=4096
-// 8KB=8192
-// 16KB=16384
-// 32KB=32768
-// 64KB=65536
-// @see https://github.com/winlinvip/simple-rtmp-server/issues/241
-#define SOCKET_READ_SIZE 65536
-// the max buffer for user space socket buffer.
-#define SOCKET_MAX_BUF SOCKET_READ_SIZE
-
 /**
 * the simple buffer use vector to append bytes,
 * it's for hls and http, and need to be refined in future.
@@ -101,11 +91,6 @@ public:
     * @remark, it only for server-side, client srs-librtmp just ignore.
     */
     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;
 };
 #endif