stream: add util function to get 'usable' data

src/stream-tcp-reassemble.c

@@ -331,6 +331,20 @@ static inline uint64_t GetAbsLastAck(const TcpStream *stream)
     }
 }
 
+uint64_t StreamTcpGetAcked(const TcpStream *stream)
+{
+    return GetAbsLastAck(stream);
+}
+
+uint64_t StreamTcpGetUsable(const TcpStream *stream, const bool eof)
+{
+    uint64_t right_edge = STREAM_BASE_OFFSET(stream) + stream->sb.buf_offset;
+    if (!eof && StreamTcpInlineMode() == FALSE) {
+        right_edge = MIN(GetAbsLastAck(stream), right_edge);
+    }
+    return right_edge;
+}
+
 #ifdef UNITTESTS
 /** \internal
  *  \brief check if segments falls before stream 'offset' */

src/stream-tcp.h

@@ -198,5 +198,8 @@ int TcpSessionPacketSsnReuse(const Packet *p, const Flow *f, const void *tcp_ssn
 void StreamTcpUpdateAppLayerProgress(TcpSession *ssn, char direction,
         const uint32_t progress);
 
+uint64_t StreamTcpGetAcked(const TcpStream *stream);
+uint64_t StreamTcpGetUsable(const TcpStream *stream, const bool eof);
+
 #endif /* __STREAM_TCP_H__ */