for #738, refine flv codec to use io interface.

@@ -241,6 +241,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_RESPONSE_DATA                 3065
 #define ERROR_REQUEST_DATA                  3066
 #define ERROR_EDGE_PORT_INVALID             3067
+#define ERROR_EXPECT_FILE_IO                3068
 
 ///////////////////////////////////////////////////////
 // HTTP/StreamCaster/KAFKA protocol error.

@@ -346,7 +346,7 @@ SrsSharedPtrMessage* SrsSharedPtrMessage::copy()
 
 SrsFlvEncoder::SrsFlvEncoder()
 {
-    reader = NULL;
+    writer = NULL;
     tag_stream = new SrsBuffer();
     
 #ifdef SRS_PERF_FAST_FLV_ENCODER
@@ -370,21 +370,11 @@ SrsFlvEncoder::~SrsFlvEncoder()
 #endif
 }
 
-int SrsFlvEncoder::initialize(SrsFileWriter* fr)
+int SrsFlvEncoder::initialize(ISrsWriter* fw)
 {
-    int ret = ERROR_SUCCESS;
-    
-    srs_assert(fr);
-    
-    if (!fr->is_open()) {
-        ret = ERROR_KERNEL_FLV_STREAM_CLOSED;
-        srs_warn("stream is not open for encoder. ret=%d", ret);
-        return ret;
-    }
-    
-    reader = fr;
-    
-    return ret;
+    srs_assert(fw);
+    writer = fw;
+    return ERROR_SUCCESS;
 }
 
 int SrsFlvEncoder::write_header()
@@ -416,14 +406,14 @@ int SrsFlvEncoder::write_header(char flv_header[9])
     int ret = ERROR_SUCCESS;
     
     // write data.
-    if ((ret = reader->write(flv_header, 9, NULL)) != ERROR_SUCCESS) {
+    if ((ret = writer->write(flv_header, 9, NULL)) != ERROR_SUCCESS) {
         srs_error("write flv header failed. ret=%d", ret);
         return ret;
     }
     
     // previous tag size.
     char pts[] = { (char)0x00, (char)0x00, (char)0x00, (char)0x00 };
-    if ((ret = reader->write(pts, 4, NULL)) != ERROR_SUCCESS) {
+    if ((ret = writer->write(pts, 4, NULL)) != ERROR_SUCCESS) {
         return ret;
     }
     
@@ -566,7 +556,7 @@ int SrsFlvEncoder::write_tags(SrsSharedPtrMessage** msgs, int count)
         iovs += 3;
     }
     
-    if ((ret = reader->writev(iovss, nb_iovss, NULL)) != ERROR_SUCCESS) {
+    if ((ret = writer->writev(iovss, nb_iovss, NULL)) != ERROR_SUCCESS) {
         if (!srs_is_client_gracefully_close(ret)) {
             srs_error("write flv tags failed. ret=%d", ret);
         }
@@ -697,7 +687,7 @@ int SrsFlvEncoder::write_tag(char* header, int header_size, char* tag, int tag_s
     iovs[2].iov_base = pre_size;
     iovs[2].iov_len = SRS_FLV_PREVIOUS_TAG_SIZE;
     
-    if ((ret = reader->writev(iovs, 3, NULL)) != ERROR_SUCCESS) {
+    if ((ret = writer->writev(iovs, 3, NULL)) != ERROR_SUCCESS) {
         if (!srs_is_client_gracefully_close(ret)) {
             srs_error("write flv tag failed. ret=%d", ret);
         }
@@ -718,21 +708,11 @@ SrsFlvDecoder::~SrsFlvDecoder()
     srs_freep(tag_stream);
 }
 
-int SrsFlvDecoder::initialize(SrsFileReader* fr)
+int SrsFlvDecoder::initialize(ISrsReader* fr)
 {
-    int ret = ERROR_SUCCESS;
-    
     srs_assert(fr);
-    
-    if (!fr->is_open()) {
-        ret = ERROR_KERNEL_FLV_STREAM_CLOSED;
-        srs_warn("stream is not open for decoder. ret=%d", ret);
-        return ret;
-    }
-    
     reader = fr;
-    
-    return ret;
+    return ERROR_SUCCESS;
 }
 
 int SrsFlvDecoder::read_header(char header[9])
@@ -842,20 +822,24 @@ SrsFlvVodStreamDecoder::~SrsFlvVodStreamDecoder()
     srs_freep(tag_stream);
 }
 
-int SrsFlvVodStreamDecoder::initialize(SrsFileReader* fr)
+int SrsFlvVodStreamDecoder::initialize(ISrsReader* fr)
 {
     int ret = ERROR_SUCCESS;
     
     srs_assert(fr);
+    reader = dynamic_cast<SrsFileReader*>(fr);
+    if (!reader) {
+        ret = ERROR_EXPECT_FILE_IO;
+        srs_error("stream is not file io. ret=%d", ret);
+        return ret;
+    }
     
-    if (!fr->is_open()) {
+    if (!reader->is_open()) {
         ret = ERROR_KERNEL_FLV_STREAM_CLOSED;
         srs_warn("stream is not open for decoder. ret=%d", ret);
         return ret;
     }
     
-    reader = fr;
-    
     return ret;
 }
 

@@ -37,7 +37,8 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #endif
 
 class SrsBuffer;
-class SrsFileWriter;
+class ISrsWriter;
+class ISrsReader;
 class SrsFileReader;
 
 #define SRS_FLV_TAG_HEADER_SIZE 11
@@ -442,7 +443,7 @@ public:
 class SrsFlvEncoder
 {
 private:
-    SrsFileWriter* reader;
+    ISrsWriter* writer;
 private:
     SrsBuffer* tag_stream;
     char tag_header[SRS_FLV_TAG_HEADER_SIZE];
@@ -453,9 +454,9 @@ public:
     /**
     * initialize the underlayer file stream.
     * @remark user can initialize multiple times to encode multiple flv files.
-    * @remark, user must free the @param fr, flv encoder never close/free it.
+    * @remark, user must free the @param fw, flv encoder never close/free it.
     */
-    virtual int initialize(SrsFileWriter* fr);
+    virtual int initialize(ISrsWriter* fw);
 public:
     /**
     * write flv header.
@@ -520,7 +521,7 @@ private:
 class SrsFlvDecoder
 {
 private:
-    SrsFileReader* reader;
+    ISrsReader* reader;
 private:
     SrsBuffer* tag_stream;
 public:
@@ -530,9 +531,9 @@ public:
     /**
     * initialize the underlayer file stream
     * @remark user can initialize multiple times to decode multiple flv files.
-    * @remark user must free the @param fr, flv decoder never close/free it.
+    * @remark user must free the @param fr, flv decoder never close/free it
     */
-    virtual int initialize(SrsFileReader* fr);
+    virtual int initialize(ISrsReader* fr);
 public:
     /**
     * read the flv header, donot including the 4bytes previous tag size.
@@ -576,7 +577,7 @@ public:
     * @remark user can initialize multiple times to decode multiple flv files.
     * @remark user must free the @param fr, flv decoder never close/free it.
     */
-    virtual int initialize(SrsFileReader* fr);
+    virtual int initialize(ISrsReader* fr);
 public:
     /**
     * read the flv header and its size.