HLS input edit to use segment cache

src/input/input_hls.cpp

@@ -100,12 +100,21 @@ static uint64_t ISO8601toUnixmillis(const std::string &ts){
 }
 
 namespace Mist{
-  // Save playlist objects for manual reloading
+  /// Save playlist objects for manual reloading
   static std::map<uint64_t, Playlist> playlistMapping;
-  // Track which segment numbers have been parsed
+
+  /// Local RAM buffer for recently accessed segments
+  std::map<std::string, Util::ResizeablePointer> segBufs;
+
+  /// Order of adding/accessing for local RAM buffer of segments
+  std::deque<std::string> segBufAccs;
+
+  /// Track which segment numbers have been parsed
   std::map<uint64_t, uint64_t> parsedSegments;
+
   /// Mutex for accesses to listEntries
   tthread::mutex entryMutex;
+
   JSON::Value playlist_urls; ///< Relative URLs to the various playlists
 
   static unsigned int plsTotalCount = 0; /// Total playlists active
@@ -232,11 +241,14 @@ namespace Mist{
     isOpen = false;
     segDL.onProgress(callbackFunc);
     encrypted = false;
+    currBuf = 0;
+    packetPtr = 0;
   }
 
   /// Returns true if packetPtr is at the end of the current segment.
   bool SegmentDownloader::atEnd() const{
-    if (!isOpen){return true;}
+    if (!isOpen || !currBuf){return true;}
+    if (buffered){return currBuf->size() <= offset + 188;}
     return segDL.isEOF();
     // return (packetPtr - segDL.const_data().data() + 188) > segDL.const_data().size();
   }
@@ -302,16 +314,30 @@ namespace Mist{
       return false;
     }else{
       // Plaintext
-      size_t len = 0;
-      segDL.readSome(packetPtr, len, 188);
-      if (len != 188 || packetPtr[0] != 0x47){
-        FAIL_MSG("Not a valid TS packet: len %zu, first byte %" PRIu8, len, (uint8_t)packetPtr[0]);
+      if (buffered){
+        if (atEnd()){return false;}
+      }else{
+        if (!currBuf){return false;}
+        while (segDL && currBuf->size() < offset + 188 + 188){
+          segDL.readSome(188, *this);
+          if (currBuf->size() < offset + 188 + 188){Util::sleep(50);}
+        }
+        if (currBuf->size() < offset + 188 + 188){return false;}
+      }
+      offset += 188;
+      packetPtr = *currBuf + offset;
+      if (!packetPtr || packetPtr[0] != 0x47){
+        FAIL_MSG("Not a valid TS packet: first byte %" PRIu8, packetPtr?(uint8_t)packetPtr[0]:0);
         return false;
       }
       return true;
     }
   }
 
+  void SegmentDownloader::dataCallback(const char *ptr, size_t size){
+    currBuf->append(ptr, size);
+  }
+
   /// Attempts to read a single TS packet from the current segment, setting packetPtr on success
   void SegmentDownloader::close(){
     packetPtr = 0;
@@ -326,12 +352,24 @@ namespace Mist{
 
     MEDIUM_MSG("Loading segment: %s, key: %s, ivec: %s", entry.filename.c_str(), hexKey.c_str(),
                hexIvec.c_str());
-    if (!segDL.open(entry.filename)){
-      FAIL_MSG("Could not open %s", entry.filename.c_str());
-      return false;
-    }
 
-    if (!segDL){return false;}
+    offset = 0;
+    buffered = segBufs.count(entry.filename);
+    if (!buffered){
+      if (!segDL.open(entry.filename)){
+        FAIL_MSG("Could not open %s", entry.filename.c_str());
+        return false;
+      }
+      if (!segDL){return false;}
+      if (segBufs.size() > 60){
+        segBufs.erase(segBufAccs.back());
+        segBufAccs.pop_back();
+      }
+      segBufAccs.push_front(entry.filename);
+    }else{
+      INFO_MSG("Reading from segment cache: %s", entry.filename.c_str());
+    }
+    currBuf = &(segBufs[entry.filename]);
 
     encrypted = false;
     outData.truncate(0);

src/input/input_hls.h

@@ -50,19 +50,23 @@ namespace Mist{
   /// Keeps the segment entry list by playlist ID
   extern std::map<uint32_t, std::deque<playListEntries> > listEntries;
 
-  class SegmentDownloader{
+  class SegmentDownloader: public Util::DataCallback{
   public:
     SegmentDownloader();
     HTTP::URIReader segDL;
     char *packetPtr;
     bool loadSegment(const playListEntries &entry);
     bool readNext();
+    virtual void dataCallback(const char *ptr, size_t size);
     void close();
     bool atEnd() const;
 
   private:
     bool encrypted;
+    bool buffered;
+    size_t offset;
     Util::ResizeablePointer outData;
+    Util::ResizeablePointer * currBuf;
     size_t encOffset;
     unsigned char tmpIvec[16];
     mbedtls_aes_context aes;