for #742, refine the io interfaces.

@@ -41,7 +41,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 /**
 * file writer, to write to file.
 */
-class SrsFileWriter : public ISrsBufferWriter
+class SrsFileWriter : public ISrsWriter
 {
 private:
     std::string path;
@@ -85,7 +85,7 @@ public:
 /**
 * file reader, to read from file.
 */
-class SrsFileReader : public ISrsBufferReader
+class SrsFileReader : public ISrsReader
 {
 private:
     std::string path;

@@ -23,19 +23,35 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 #include <srs_kernel_io.hpp>
 
-ISrsBufferReader::ISrsBufferReader()
+ISrsReader::ISrsReader()
 {
 }
 
-ISrsBufferReader::~ISrsBufferReader()
+ISrsReader::~ISrsReader()
 {
 }
 
-ISrsBufferWriter::ISrsBufferWriter()
+ISrsStreamWriter::ISrsStreamWriter()
 {
 }
 
-ISrsBufferWriter::~ISrsBufferWriter()
+ISrsStreamWriter::~ISrsStreamWriter()
+{
+}
+
+ISrsVectorWriter::ISrsVectorWriter()
+{
+}
+
+ISrsVectorWriter::~ISrsVectorWriter()
+{
+}
+
+ISrsWriter::ISrsWriter()
+{
+}
+
+ISrsWriter::~ISrsWriter()
 {
 }
 

@@ -36,33 +36,42 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #endif
 
 /**
- * the reader for the buffer to read from whatever channel.
+ * The reader to read data from channel.
  */
-class ISrsBufferReader
+class ISrsReader
 {
 public:
-    ISrsBufferReader();
-    virtual ~ISrsBufferReader();
-    // for protocol/amf0/msg-codec
+    ISrsReader();
+    virtual ~ISrsReader();
 public:
     virtual int read(void* buf, size_t size, ssize_t* nread) = 0;
 };
 
 /**
- * the writer for the buffer to write to whatever channel.
+ * The writer to write stream data to channel.
  */
-class ISrsBufferWriter
+class ISrsStreamWriter
 {
 public:
-    ISrsBufferWriter();
-    virtual ~ISrsBufferWriter();
-    // for protocol
+    ISrsStreamWriter();
+    virtual ~ISrsStreamWriter();
 public:
     /**
      * write bytes over writer.
      * @nwrite the actual written bytes. NULL to ignore.
      */
     virtual int write(void* buf, size_t size, ssize_t* nwrite) = 0;
+};
+
+/**
+ * The vector writer to write vector(iovc) to channel.
+ */
+class ISrsVectorWriter
+{
+public:
+    ISrsVectorWriter();
+    virtual ~ISrsVectorWriter();
+public:
     /**
      * write iov over writer.
      * @nwrite the actual written bytes. NULL to ignore.
@@ -70,5 +79,15 @@ public:
     virtual int writev(const iovec *iov, int iov_size, ssize_t* nwrite) = 0;
 };
 
+/**
+ * The generally writer, stream and vector writer.
+ */
+class ISrsWriter : virtual public ISrsStreamWriter, virtual public ISrsVectorWriter
+{
+public:
+    ISrsWriter();
+    virtual ~ISrsWriter();
+};
+
 #endif
 

@@ -341,7 +341,7 @@ int SimpleSocketStream::connect(const char* server_ip, int port)
     return srs_hijack_io_connect(io, server_ip, port);
 }
 
-// ISrsBufferReader
+// ISrsReader
 int SimpleSocketStream::read(void* buf, size_t size, ssize_t* nread)
 {
     srs_assert(io);

@@ -53,7 +53,7 @@ public:
     virtual srs_hijack_io_t hijack_io();
     virtual int create_socket(srs_rtmp_t owner);
     virtual int connect(const char* server, int port);
-// ISrsBufferReader
+// ISrsReader
 public:
     virtual int read(void* buf, size_t size, ssize_t* nread);
 // ISrsProtocolReader

@@ -34,15 +34,20 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 /**
 * the system io reader/writer architecture:
-+---------------+     +--------------------+      +---------------+
-| IBufferReader |     |    IStatistic      |      | IBufferWriter |
-+---------------+     +--------------------+      +---------------+
-| + read()      |     | + get_recv_bytes() |      | + write()     |
-+------+--------+     | + get_send_bytes() |      | + writev()    |
-      / \             +---+--------------+-+      +-------+-------+
-       |                 / \            / \              / \
-       |                  |              |                |
-+------+------------------+-+      +-----+----------------+--+
+                                        +---------------+  +---------------+
+                                        | IStreamWriter |  | IVectorWriter |
+                                        +---------------+  +---------------+
+                                        | + write()     |  | + writev()    |
+                                        +-------------+-+  ++--------------+
++----------+     +--------------------+               /\   /\
+| IReader  |     |    IStatistic      |                 \ /
++----------+     +--------------------+                  V
+| + read() |     | + get_recv_bytes() |           +------+----+
++------+---+     | + get_send_bytes() |           |  IWriter  |
+      / \        +---+--------------+-+           +-------+---+
+       |            / \            / \                   / \
+       |             |              |                     |
++------+-------------+------+      ++---------------------+--+
 | IProtocolReader           |      | IProtocolWriter         |
 +---------------------------+      +-------------------------+
 | + readfully()             |      | + set_send_timeout()    |
@@ -80,7 +85,7 @@ public:
 /**
 * the reader for the protocol to read from whatever channel.
 */
-class ISrsProtocolReader : public virtual ISrsBufferReader, public virtual ISrsProtocolStatistic
+class ISrsProtocolReader : public virtual ISrsReader, public virtual ISrsProtocolStatistic
 {
 public:
     ISrsProtocolReader();
@@ -108,7 +113,7 @@ public:
 /**
 * the writer for the protocol to write to whatever channel.
 */
-class ISrsProtocolWriter : public virtual ISrsBufferWriter, public virtual ISrsProtocolStatistic
+class ISrsProtocolWriter : public virtual ISrsWriter, public virtual ISrsProtocolStatistic
 {
 public:
     ISrsProtocolWriter();

@@ -131,7 +131,7 @@ void SrsFastStream::skip(int size)
     p += size;
 }
 
-int SrsFastStream::grow(ISrsBufferReader* reader, int required_size)
+int SrsFastStream::grow(ISrsReader* reader, int required_size)
 {
     int ret = ERROR_SUCCESS;
 

@@ -60,7 +60,7 @@ public:
 * the buffer provices bytes cache for protocol. generally, 
 * protocol recv data from socket, put into buffer, decode to RTMP message.
 * Usage:
-*       ISrsBufferReader* r = ......;
+*       ISrsReader* r = ......;
 *       SrsFastStream* fb = ......;
 *       fb->grow(r, 1024);
 *       char* header = fb->read_slice(100);
@@ -138,7 +138,7 @@ public:
     * @return an int error code, error if required_size negative.
     * @remark, we actually maybe read more than required_size, maybe 4k for example.
     */
-    virtual int grow(ISrsBufferReader* reader, int required_size);
+    virtual int grow(ISrsReader* reader, int required_size);
 public:
 #ifdef SRS_PERF_MERGED_READ
     /**

@@ -33,7 +33,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_kernel_file.hpp>
 #include <srs_protocol_stream.hpp>
 
-class MockBufferReader: public ISrsBufferReader
+class MockBufferReader: public ISrsReader
 {
 private:
     std::string str;