|
static private ReadInput ( System sourceStream, byte target, int start, int count ) : |
||
| sourceStream | System | The source Stream to ReadPos from. |
| target | byte | Contains the array of characters ReadPos from the source Stream. |
| start | int | The starting index of the target array. |
| count | int | The maximum number of characters to ReadPos from the source Stream. |
| return | ||
/// <summary>
/// Skips n decompressed bytes in the stream.
/// </summary>
/// <param name="n">The number of bytes to skip.</param>
public long Skip(long n)
{
int len = 512;
if (n < len)
{
len = (int)n;
}
byte[] tmp = new byte[len];
return((long)ZLibUtil.ReadInput(this, tmp, 0, tmp.Length));
}
/// <summary>
/// Reads a number of decompressed bytes into the specified byte array.
/// </summary>
/// <param name="buffer">The array used to store decompressed bytes.</param>
/// <param name="offset">The location in the array to begin reading.</param>
/// <param name="count">The number of decompressed bytes to read.</param>
/// <returns>The number of bytes that were decompressed into the byte array.</returns>
/// <example> The following code demonstrates how to use the <c>ZInputStream</c> to decompresses data
/// <code>
/// [C#]
/// private void decompressFile(string inFile, string outFile)
/// {
/// /* Create a file to store decompressed data */
/// System.IO.FileStream decompressedFile = new System.IO.FileStream(@"c:\data\decompressed.dat", System.IO.FileMode.Create);
/// /* Open a file containing compressed data */
/// System.IO.FileStream compressedFile = new System.IO.FileStream(@"c:\data\compressed.dat", System.IO.FileMode.Open);
/// /* Create ZInputStream for decompression */
/// ZInputStream decompressionStream = new ZInputStream(compressedFile);
///
/// try
/// {
/// byte[] buffer = new byte[2000];
/// int len;
/// /* Read and decompress data */
/// while ((len = decompressionStream.Read(buffer, 0, 2000)) > 0)
/// {
/// /* Store decompressed data */
/// decompressedFile.Write(buffer, 0, len);
/// }
/// }
/// finally
/// {
/// decompressionStream.Close();
/// decompressedFile.Close();
/// compressedFile.Close();
/// }
/// }
/// </code>
/// </example>
public override int Read(byte[] buffer, int offset, int count)
{
if (count == 0)
{
return(0);
}
if (this.needCopyArrays && ZLibUtil.CopyLargeArrayToSmall.GetRemainingDataSize() > 0)
{
return(ZLibUtil.CopyLargeArrayToSmall.CopyData());
}
else
{
this.needCopyArrays = false;
}
bool call_finish = false;
int err;
z.next_out = buffer;
z.next_out_index = offset;
z.avail_out = count;
do
{
if ((z.avail_in == 0) && (!nomoreinput))
{
// if buffer is empty and more input is available, refill it
z.next_in_index = 0;
z.avail_in = ZLibUtil.ReadInput(_stream, buf, 0, ZLibUtil.zLibBufSize); //(ZLibUtil.zLibBufSize<z._avail_out ? ZLibUtil.zLibBufSize : z._avail_out));
if (z.avail_in == -1)
{
z.avail_in = 0;
nomoreinput = true;
}
}
if ((z.avail_in == 0) && nomoreinput)
{
call_finish = true;
break;
}
err = z.inflate(flush);
if (nomoreinput && (err == (int)ZLibResultCode.Z_BUF_ERROR))
{
return(-1);
}
if (err != (int)ZLibResultCode.Z_OK && err != (int)ZLibResultCode.Z_STREAM_END)
{
throw new ZStreamException("inflating: " + z.msg);
}
if (nomoreinput && (z.avail_out == count))
{
return(-1);
}
}while (z.avail_out == count && err == (int)ZLibResultCode.Z_OK);
if (call_finish)
{
return(Finish(buffer, offset, count));
}
return(count - z.avail_out);
}
