/// <summary> thread-singleton crc engine </summary>
 public static Zlib.CRC32 GetCRC()
 {
     if (crc32Engine == null)
     {
         crc32Engine = new Zlib.CRC32();
     }
     return(crc32Engine);
 }
コード例 #2
0
 /// <summary>
 /// Constructor must be called just after reading length and id of first IDAT
 /// chunk
 /// </summary>
 ///
 public PngIDatChunkInputStream(Stream iStream, int lenFirstChunk, long offset_0)
 {
     this.idLastChunk     = new byte[4];
     this.toReadThisChunk = 0;
     this.ended           = false;
     this.foundChunksInfo = new List <IdatChunkInfo>();
     this.offset          = offset_0;
     checkCrc             = true;
     inputStream          = iStream;
     crcEngine            = new CRC32();
     this.lenLastChunk    = lenFirstChunk;
     toReadThisChunk      = lenFirstChunk;
     // we know it's a IDAT
     System.Array.Copy((Array)(Pngcs.Chunks.ChunkHelper.b_IDAT), 0, (Array)(idLastChunk), 0, 4);
     crcEngine.Update(idLastChunk, 0, 4);
     foundChunksInfo.Add(new PngIDatChunkInputStream.IdatChunkInfo(lenLastChunk, offset_0 - 8));
     // PngHelper.logdebug("IDAT Initial fragment: len=" + lenLastChunk);
     if (this.lenLastChunk == 0)
     {
         EndChunkGoForNext(); // rare, but...
     }
 }