Write() public method

Write data to the stream.

To use the ParallelDeflateOutputStream to compress data, create a ParallelDeflateOutputStream with CompressionMode.Compress, passing a writable output stream. Then call Write() on that ParallelDeflateOutputStream, providing uncompressed data as input. The data sent to the output stream will be the compressed form of the data written.

To decompress data, use the Ionic.Zlib.DeflateStream class.

public Write ( byte buffer, int offset, int count ) : void
buffer byte The buffer holding data to write to the stream.
offset int the offset within that data array to find the first byte to write.
count int the number of bytes to write.
return void
ParallelDeflateOutputStream Class Documentation
Exemplo n.º 1
0
        public void Zlib_ParallelDeflateStream()
        {
            var sw = new System.Diagnostics.Stopwatch();
            sw.Start();
            TestContext.WriteLine("{0}: Zlib_ParallelDeflateStream Start", sw.Elapsed);

            int sz = 256*1024 + this.rnd.Next(120000);
            string FileToCompress = System.IO.Path.Combine(TopLevelDir, String.Format("Zlib_ParallelDeflateStream.{0}.txt", sz));

            CreateAndFillFileText( FileToCompress, sz);

            TestContext.WriteLine("{0}: Created file: {1}", sw.Elapsed, FileToCompress );

            byte[] original = File.ReadAllBytes(FileToCompress);

            int crc1 = DoCrc(FileToCompress);

            TestContext.WriteLine("{0}: Original CRC: {1:X8}", sw.Elapsed, crc1 );

            byte[] working = new byte[WORKING_BUFFER_SIZE];
            int n = -1;
            long originalLength;
            MemoryStream ms1 = new MemoryStream();
            {
                using (FileStream fs1 = File.OpenRead(FileToCompress))
                {
                    originalLength = fs1.Length;
                    using (var compressor = new Ionic.Zlib.ParallelDeflateOutputStream(ms1, true))
                    {
                        while ((n = fs1.Read(working, 0, working.Length)) != 0)
                        {
                            compressor.Write(working, 0, n);
                        }
                    }
                }
                ms1.Seek(0, SeekOrigin.Begin);
            }

            TestContext.WriteLine("{0}: Compressed {1} bytes into {2} bytes", sw.Elapsed,
                                  originalLength, ms1.Length);

            var crc = new Ionic.Crc.CRC32();
            int crc2= 0;
            byte[] decompressedBytes= null;
            using (MemoryStream ms2 = new MemoryStream())
            {
                using (var decompressor = new DeflateStream(ms1, CompressionMode.Decompress, false))
                {
                    while ((n = decompressor.Read(working, 0, working.Length)) != 0)
                    {
                        ms2.Write(working, 0, n);
                    }
                }
                TestContext.WriteLine("{0}: Decompressed", sw.Elapsed);
                TestContext.WriteLine("{0}: Decompressed length: {1}", sw.Elapsed, ms2.Length);
                ms2.Seek(0, SeekOrigin.Begin);
                crc2 = crc.GetCrc32(ms2);
                decompressedBytes = ms2.ToArray();
                TestContext.WriteLine("{0}: Decompressed CRC: {1:X8}", sw.Elapsed, crc2 );
            }


            TestContext.WriteLine("{0}: Checking...", sw.Elapsed );

            bool check = true;
            if (originalLength != decompressedBytes.Length)
            {
                TestContext.WriteLine("Different lengths.");
                check = false;
            }
            else
            {
                for (int i = 0; i < decompressedBytes.Length; i++)
                {
                    if (original[i] != decompressedBytes[i])
                    {
                        TestContext.WriteLine("byte {0} differs", i);
                        check = false;
                        break;
                    }
                }
            }

            Assert.IsTrue(check,"Data check failed");
            TestContext.WriteLine("{0}: Done...", sw.Elapsed );
        }
Exemplo n.º 2
0
        public void Zlib_ParallelDeflateStream2()
        {
            var sw = new System.Diagnostics.Stopwatch();
            sw.Start();
            TestContext.WriteLine("{0}: Zlib_ParallelDeflateStream2 Start", sw.Elapsed);
            int sz = (128 * 1024) /*default buffer size*/ * rnd.Next(14, 28);
            using (Stream s = new MemoryStream())
            {
                TestContext.WriteLine("{0}: Creating zip...", sw.Elapsed);
                using (Stream compressor = new Ionic.Zlib.ParallelDeflateOutputStream(s, true))
                    compressor.Write(new byte[sz], 0, sz);

                s.Position = 0;
                TestContext.WriteLine("{0}: Trying to extract...", sw.Elapsed);
                using (Stream decompressor = new Ionic.Zlib.DeflateStream(s, Ionic.Zlib.CompressionMode.Decompress, true))
                {
                    try
                    {
                        int bread = decompressor.Read(new byte[sz], 0, sz);
                        Assert.AreEqual(sz, bread, "Size of decompressed bytes does not match size of input bytes");
                    }
                    catch (Ionic.Zlib.ZlibException)
                    {
                        Assert.Fail("ParallelDeflate failed");
                    }
                }
            }
            TestContext.WriteLine("{0}: Done...", sw.Elapsed);
        }