refine the fast buffer to more readable.

@@ -82,17 +82,21 @@ char* SrsFastBuffer::bytes()
 
 
 void SrsFastBuffer::set_buffer(int buffer_size)
 void SrsFastBuffer::set_buffer(int buffer_size)
 {
 {
-    // the user-space buffer size limit to a max value.
-    int nb_resize_buf = srs_min(buffer_size, SRS_MAX_SOCKET_BUFFER);
+    // never exceed the max size.
     if (buffer_size > SRS_MAX_SOCKET_BUFFER) {
     if (buffer_size > SRS_MAX_SOCKET_BUFFER) {
-        srs_warn("limit the user-space buffer from %d to %d", buffer_size, SRS_MAX_SOCKET_BUFFER);
+        srs_warn("limit the user-space buffer from %d to %d", 
+            buffer_size, SRS_MAX_SOCKET_BUFFER);
     }
     }
     
     
+    // the user-space buffer size limit to a max value.
+    int nb_resize_buf = srs_min(buffer_size, SRS_MAX_SOCKET_BUFFER);
+
     // only realloc when buffer changed bigger
     // only realloc when buffer changed bigger
     if (nb_resize_buf <= nb_buffer) {
     if (nb_resize_buf <= nb_buffer) {
         return;
         return;
     }
     }
     
     
+    // realloc for buffer change bigger.
     int start = p - buffer;
     int start = p - buffer;
     int nb_bytes = end - p;
     int nb_bytes = end - p;
     
     
@@ -148,6 +152,7 @@ int SrsFastBuffer::grow(ISrsBufferReader* reader, int required_size)
         srs_assert(nb_exists_bytes >= 0);
         srs_assert(nb_exists_bytes >= 0);
         srs_verbose("move fast buffer %d bytes", nb_exists_bytes);
         srs_verbose("move fast buffer %d bytes", nb_exists_bytes);
 
 
+        // reset or move to get more space.
         if (!nb_exists_bytes) {
         if (!nb_exists_bytes) {
             // reset when buffer is empty.
             // reset when buffer is empty.
             p = end = buffer;
             p = end = buffer;
@@ -159,7 +164,6 @@ int SrsFastBuffer::grow(ISrsBufferReader* reader, int required_size)
             p = buffer;
             p = buffer;
             end = p + nb_exists_bytes;
             end = p + nb_exists_bytes;
         }
         }
-    }
         
         
         // check whether enough free space in buffer.
         // check whether enough free space in buffer.
         nb_free_space = buffer + nb_buffer - end;
         nb_free_space = buffer + nb_buffer - end;
@@ -169,6 +173,7 @@ int SrsFastBuffer::grow(ISrsBufferReader* reader, int required_size)
                 required_size, nb_buffer, nb_free_space, ret);
                 required_size, nb_buffer, nb_free_space, ret);
             return ret;
             return ret;
         }
         }
+    }
 
 
     // buffer is ok, read required size of bytes.
     // buffer is ok, read required size of bytes.
     while (end - p < required_size) {
     while (end - p < required_size) {