donot mix the read and write for librtmp

trunk/src/kernel/srs_kernel_error.hpp

@@ -120,6 +120,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_SYSTEM_CREATE_PIPE            430
 #define ERROR_SYSTEM_FILE_SEEK              431
 #define ERROR_SYSTEM_FLV_HEADER             432
+#define ERROR_SYSTEM_IO_INVALID             433
 
 // see librtmp.
 // failed when open ssl create the dh

trunk/src/kernel/srs_kernel_flv.cpp

@@ -165,6 +165,11 @@ void SrsFileReader::close()
     return;
 }
 
+bool SrsFileReader::is_open()
+{
+    return fd > 0;
+}
+
 int64_t SrsFileReader::tellg()
 {
     return (int64_t)::lseek(fd, 0, SEEK_CUR);

trunk/src/kernel/srs_kernel_flv.hpp

@@ -69,6 +69,7 @@ public:
     virtual int open(std::string file);
     virtual void close();
 public:
+    virtual bool is_open();
     virtual int64_t tellg();
     virtual void skip(int64_t size);
     virtual int64_t lseek(int64_t offset);