/// <summary>
/// Fills the <see cref="readBuffers"/> with more data from the underlying stream
/// passed through all the stream filters.
/// </summary>
/// <param name="chunkSize">Maximum number of bytes to be read from the stream.</param>
/// <returns>A <see cref="string"/> or <see cref="PhpBytes"/> containing the
/// data as returned from the last stream filter or <b>null</b> in case of an error or <c>EOF</c>.</returns>
protected TextElement ReadFiltered(int chunkSize)
{
byte[] chunk = new byte[chunkSize];
var filtered = TextElement.Null;
while (filtered.IsNull)
{
// Read data until there is an output or error or EOF.
if (RawEof) return TextElement.Null;
int read = RawRead(chunk, 0, chunkSize);
if (read <= 0)
{
// Error or EOF.
return TextElement.Null;
}
if (read < chunkSize)
{
byte[] sub = new byte[read];
Array.Copy(chunk, 0, sub, 0, read);
chunk = sub;
}
filtered = new TextElement(chunk);
bool closing = RawEof;
if (textReadFilter != null)
{
// First use the text-input filter if any.
filtered = textReadFilter.Filter(_ctx, filtered, closing);
}
if (readFilters != null)
{
// After that apply the user-filters.
foreach (IFilter f in readFilters)
{
if (filtered.IsNull)
{
// This is the last chance to output something. Give chance to all filters.
if (closing) filtered = TextElement.Empty;
else break; // Continue with next RawRead()
}
filtered = f.Filter(_ctx, filtered, closing);
} // foreach
} // if
} // while
return filtered;
}
/// <summary>
/// Put a buffer at the end of the <see cref="readBuffers"/>.
/// </summary>
/// <param name="data">The buffer to append.</param>
internal void EnqueueReadBuffer(TextElement data)
{
Debug.Assert(!data.IsNull);
// This may be the first access to the buffers.
if (readBuffers == null)
readBuffers = new Queue<TextElement>(2);
// Append the filtered output to the buffers.
readBuffers.Enqueue(data);
}
/// <summary>
/// Split a <see cref="String"/> or <see cref="PhpBytes"/> to "upto" bytes at left and the rest or <c>null</c> at right.
/// </summary>
private static void SplitData(TextElement data, int upto, out TextElement left, out TextElement right)
{
Debug.Assert(upto >= 0);
//if (this.IsText)
if (data.IsText)
{
string s = data.GetText();
if (upto < s.Length - 1)
{
left = new TextElement(s.Substring(0, upto + 1));
right = new TextElement(s.Substring(upto + 2));
}
else
{
left = data;
right = TextElement.Null;
}
}
else
{
Debug.Assert(data.IsBinary);
var bin = data.GetBytes();
if (upto < bin.Length - 1)
{
byte[] l = new byte[upto + 1], r = new byte[bin.Length - upto - 1];
Array.Copy(bin, 0, l, 0, upto + 1);
Array.Copy(bin, upto + 1, r, 0, bin.Length - upto - 1);
left = new TextElement(l);
right = new TextElement(r);
}
else
{
left = data;
right = TextElement.Null;
}
}
}
/// <summary>
/// Passes the data through output filter-chain to the output buffer.
/// When the buffer is full or buffering is disabled, passes the data to the low-level stream.
/// </summary>
/// <param name="data">The data to store (filters will handle the type themselves).</param>
/// <param name="closing"><c>true</c> when this method is called from <c>close()</c>
/// to prune all the pending filters with closing set to <c>true</c>.</param>
/// <returns>Number of character entities successfully written or <c>-1</c> on an error.</returns>
protected int WriteData(TextElement data, bool closing = false)
{
// Set file access to writing
CurrentAccess = FileAccess.Write;
if (!CanWrite) return -1;
Debug.Assert(!data.IsNull);
int consumed = data.Length;
writeFilteredCount += consumed;
if (writeFilters != null)
{
// Process the data through the custom write filters first.
foreach (IFilter f in writeFilters)
{
if (data.IsNull)
{
// When closing, feed all the filters with data.
if (closing) data = TextElement.Empty;
else return consumed; // Eaten all
}
data = f.Filter(_ctx, data, closing);
if (closing) f.OnClose();
}
}
if (textWriteFilter != null)
{
// Then pass it through the text-conversion filter if any.
data = textWriteFilter.Filter(_ctx, data, closing);
}
// From now on, the data is treated just as binary
byte[] bin = data.AsBytes(_ctx.StringEncoding);
if (bin.Length == 0)
{
return consumed;
}
// Append the resulting data to the output buffer if any.
if (IsWriteBuffered)
{
// Is this the first access?
if (writeBuffer == null)
{
writeBuffer = new byte[writeBufferSize];
writePosition = 0;
}
// The whole binary data fits in the buffer, great!
if (writeBufferSize - writePosition > bin.Length)
{
Array.Copy(bin, 0, writeBuffer, writePosition, bin.Length);
writePosition += bin.Length;
return consumed;
}
int copied = 0;
// Use the buffer for small data only
if (writeBufferSize > bin.Length)
{
// Otherwise fill the buffer and flush it.
copied = writeBufferSize - writePosition;
Array.Copy(bin, 0, writeBuffer, writePosition, copied);
writePosition += copied;
}
// Flush the buffer
if ((writePosition > 0) && (!FlushWriteBuffer()))
return (copied > 0) ? copied : -1; // It is an error but still some output was written.
if (bin.Length - copied >= writeBufferSize)
{
// If the binary data is really big, write it directly to stream.
while (copied < bin.Length)
{
int written = RawWrite(bin, copied, bin.Length - copied);
if (written <= 0)
{
PhpException.Throw(PhpError.Warning, ErrResources.stream_write_failed, copied.ToString(), bin.Length.ToString());
return (copied > 0) ? copied : -1; // It is an error but still some output was written.
}
copied += written;
writeOffset += written;
}
}
else
{
// Otherwise just start a new buffer with the rest of the data.
Array.Copy(bin, copied, writeBuffer, 0, bin.Length - copied);
writePosition = bin.Length - copied;
}
return consumed;
}
else
{
// No write buffer. Write the data directly.
int copied = 0;
while (copied < bin.Length)
{
int written = RawWrite(bin, copied, bin.Length - copied);
if (written <= 0)
{
PhpException.Throw(PhpError.Warning, ErrResources.stream_write_failed, copied.ToString(), bin.Length.ToString());
return (copied > 0) ? copied : -1; // ERROR but maybe some was written.
}
copied += written;
writeOffset += written;
}
return consumed;
}
}
/// <summary> /// Processes the <paramref name="input"/> (either of type <see cref="string"/> or <see cref="byte"/>[]) /// data and returns the filtered data in one of the formats above or <c>null</c>. /// </summary> public abstract TextElement Filter(Context ctx, TextElement input, bool closing);
/// <summary>
/// Finds the '\n' in a string or PhpBytes and returns its offset or <c>-1</c>
/// if not found.
/// </summary>
/// <param name="data">Data to scan.</param>
/// <param name="from">Index of the first character to scan.</param>
/// <returns></returns>
private static int FindEoln(TextElement data, int from)
{
Debug.Assert(!data.IsNull);
if (data.IsText)
{
return data.GetText().IndexOf('\n', from);
}
else
{
Debug.Assert(data.IsBinary);
return Array.IndexOf(data.GetBytes(), (byte)'\n', from);
}
}
/// <summary>
/// Processes the <paramref name="input"/> (either of type <see cref="string"/> or <see cref="byte"/>[])
/// data and returns the filtered data in one of the formats above or <c>null</c>.
/// </summary>
public TextElement Filter(Context ctx, TextElement input, bool closing)
{
string str = input.AsText(ctx.StringEncoding);
if (pending)
{
// Both \r\n together make a pair which would consume a pending \r.
if (str.Length == 0) str = "\r";
else if (str[0] != '\n') str.Insert(0, "\r");
}
// Replace the pair.
str = str.Replace("\r\n", "\n");
if (str.Length != 0)
{
// Check for pending \r at the end.
pending = str[str.Length - 1] == '\r';
// Postpone the resolution of \r\n vs. \r to the next filtering if this is not the last one.
if (!closing && pending) str.Remove(str.Length - 1, 1);
}
//
return new TextElement(str);
}
/// <summary>
/// Processes the <paramref name="input"/> (either of type <see cref="string"/> or <see cref="byte"/>[])
/// data and returns the filtered data in one of the formats above or <c>null</c>.
/// </summary>
public TextElement Filter(Context ctx, TextElement input, bool closing)
{
return new TextElement(input.AsText(ctx.StringEncoding).Replace("\n", "\r\n"));
}
/// <summary>
/// Processes the <paramref name="input"/> (either of type <see cref="string"/> or <see cref="byte"/>[])
/// data and returns the filtered data in one of the formats above or <c>null</c>.
/// </summary>
public TextElement Filter(Context ctx, TextElement input, bool closing)
{
return(new TextElement(input.AsText(ctx.StringEncoding).Replace("\n", "\r\n")));
}
/// <summary> /// Processes the <paramref name="input"/> (either of type <see cref="string"/> or <see cref="byte"/>[]) /// data and returns the filtered data in one of the formats above or <c>null</c>. /// </summary> public abstract TextElement Filter(Context ctx, TextElement input, bool closing);
/// <summary> /// Processes the <paramref name="input"/> (either of type <see cref="string"/> or <see cref="byte"/>[]) /// data and returns the filtered data in one of the formats above or <c>null</c>. /// </summary> public abstract TextElement Filter(IEncodingProvider enc, TextElement input, bool closing);
/// <summary>
/// Processes the <paramref name="input"/> (either of type <see cref="string"/> or <see cref="byte"/>[])
/// data and returns the filtered data in one of the formats above or <c>null</c>.
/// </summary>
public TextElement Filter(IEncodingProvider enc, TextElement input, bool closing)
{
return(new TextElement(input.AsText(enc.StringEncoding).Replace("\n", "\r\n")));
}
public override TextElement Filter(IEncodingProvider enc, TextElement input, bool closing)
{
// TODO: not the most efficient method - after the filters are upgraded to bucket lists, update this
var bInput = input.AsBytes(enc.StringEncoding);
if (bInput != null)
{
if (_state == UncompressionState.Failed)
{
// failed filter should not get any more calls
PhpException.Throw(PhpError.Warning, "using filter in failed state");
return(TextElement.Null);
}
if (_state == UncompressionState.PostTrailer)
{
// post trailer - ignore everything
if (closing)
{
_state = UncompressionState.Finished;
}
return(TextElement.Empty);
}
if (_state == UncompressionState.Finished)
{
// finished filter should not get any more data
PhpException.Throw(PhpError.Warning, "using filter in finished state");
return(TextElement.Null);
}
if (_state == UncompressionState.Passthrough)
{
// this is not gzip data format - pass the data through
return(new TextElement(bInput));
}
// enqueue the block
_chunkQueue.EnqueueByteBlock(bInput, 0, bInput.Length);
if (_state == UncompressionState.Header)
{
#region Header handling
//beginning of the stream
byte[] beginning = _chunkQueue.DequeueByteBlock(Zlib.GZIP_HEADER_LENGTH);
if (beginning == null && !closing)
{
// we do not have enough data, but we know there would be more data ahead
return(TextElement.Empty);
}
else
{
//check the header format
if (beginning.Length >= 2 && beginning[0] == Zlib.GZIP_HEADER[0] && beginning[1] == Zlib.GZIP_HEADER[1])
{
//header magic bytes are OK
if (beginning.Length < Zlib.GZIP_HEADER_LENGTH)
{
// header is too short -> this is an error
PhpException.Throw(PhpError.Warning, "unexpected end of file");
return(TextElement.Null);
}
else
{
// check the rest of the header
if (beginning[2] != Zlib.Z_DEFLATED)
{
PhpException.Throw(PhpError.Warning, "unknown compression method");
return(TextElement.Null);
}
if ((beginning[3] & Zlib.GZIP_HEADER_RESERVED_FLAGS) != 0)
{
PhpException.Throw(PhpError.Warning, "unknown header flags set");
return(TextElement.Null);
}
_headerFlags = beginning[3];
//change the header state based on the header flags
UpdateHeaderState();
}
}
else
{
// this is not a gzip format -> passthrough the data
_state = UncompressionState.Passthrough;
return(new TextElement(beginning));
}
}
#endregion
}
if (_state == UncompressionState.HeaderExtraField)
{
#region Header Extra Field Handling
if (_extraHeaderLength == null)
{
//length was not yet detected
if (_chunkQueue.AvailableBytes < 2)
{
//wait for more input
return(TextElement.Empty);
}
else
{
//assemble length
_extraHeaderLength = _chunkQueue.DequeueByte();
_extraHeaderLength &= (_chunkQueue.DequeueByte() << 8);
}
}
if (_extraHeaderLength != null)
{
//length was already read
if (_chunkQueue.AvailableBytes < _extraHeaderLength)
{
//wait for more input
return(TextElement.Empty);
}
else
{
Debug.Assert(_extraHeaderLength.HasValue);
//skip the extra header
_chunkQueue.SkipByteBlock(_extraHeaderLength.Value);
UpdateHeaderState();
}
}
#endregion
}
if (_state == UncompressionState.HeaderFilename || _state == UncompressionState.HeaderComment)
{
#region Header Filename and Comment Handling
// filename or comment
// cycle until input ends or zero character is encountered
while (true)
{
byte?nextByte = _chunkQueue.DequeueByte();
if (nextByte == null)
{
//wait for more input
return(TextElement.Empty);
}
if (nextByte == 0)
{
// end the cycle
break;
}
}
// go to the next state
UpdateHeaderState();
#endregion
}
if (_state == UncompressionState.HeaderCRC)
{
#region CRC Handling
// header CRC
if (_chunkQueue.AvailableBytes < 2)
{
//wait for more input
return(TextElement.Empty);
}
else
{
//skip the CRC
_chunkQueue.DequeueByte();
_chunkQueue.DequeueByte();
UpdateHeaderState();
}
#endregion
}
//filled by data handling and sometimes returned by trailer handling
byte[] output = null;
if (_state == UncompressionState.Data)
{
#region Deflated Data Handling
//get all available bytes
byte[] inputBytes = _chunkQueue.DequeueByteBlock(_chunkQueue.AvailableBytes);
int inputOffset = 0;
// perform the inner operation
try
{
output = FilterInner(inputBytes, ref inputOffset, closing);
}
catch
{
// exception was thrown
_state = UncompressionState.Failed;
throw;
}
if (output == null)
{
// error happened and exception was not thrown
_state = UncompressionState.Failed;
return(TextElement.Null);
}
// update the hash algorithm
_crc.Update(output);
if (inputOffset != inputBytes.Length)
{
// push the rest of the data into the chunk queue
_chunkQueue.PushByteBlock(inputBytes, inputOffset, inputBytes.Length - inputOffset);
// end of deflated block reached
_state = UncompressionState.Trailer;
// pass through to Trailer handling
}
else
{
//normal decompressed block - return it
return(new TextElement(output));
}
#endregion
}
if (_state == UncompressionState.Trailer)
{
#region Trailer Handling
// the deflate block has already ended, we are processing trailer
if (closing || _chunkQueue.AvailableBytes >= Zlib.GZIP_FOOTER_LENGTH)
{
byte[] trailer;
trailer = _chunkQueue.DequeueByteBlock(_chunkQueue.AvailableBytes);
if (trailer.Length >= Zlib.GZIP_FOOTER_LENGTH)
{
byte[] crc = _crc.Final();
if (crc[3] != trailer[0] || crc[2] != trailer[1] || crc[1] != trailer[2] || crc[0] != trailer[3])
{
_state = UncompressionState.Failed;
PhpException.Throw(PhpError.Warning, "incorrect data check");
return(TextElement.Null);
}
if (BitConverter.ToInt32(trailer, 4) != _stream.total_out)
{
_state = UncompressionState.Failed;
PhpException.Throw(PhpError.Warning, "incorrect length check");
return(TextElement.Null);
}
_state = closing ? UncompressionState.Finished : UncompressionState.PostTrailer;
// everything is fine, return the output if available
return(output != null ? new TextElement(output) : TextElement.Empty);
}
else
{
_state = UncompressionState.Failed;
PhpException.Throw(PhpError.Warning, "unexpected end of file");
return(TextElement.Null);
}
}
else
{
//stream is not closing yet - return the remaining output, otherwise empty
return(output != null ? new TextElement(output) : TextElement.Empty);
}
#endregion
}
//this should not happen
Debug.Fail(null);
return(TextElement.Null);
}
else
{
Debug.Fail("GzipUncompressionFilter expects chunks to be convertible to PhpBytes.");
return(TextElement.Null);
}
}
public override TextElement Filter(IEncodingProvider enc, TextElement input, bool closing)
{
var bInput = input.AsBytes(enc.StringEncoding);
if (bInput != null)
{
if (_state == CompressionState.Failed)
{
PhpException.Throw(PhpError.Warning, "using filter in failed state");
return(TextElement.Null);
}
if (_state == CompressionState.Finished)
{
PhpException.Throw(PhpError.Warning, "using filter in finished state");
return(TextElement.Null);
}
byte[] header = null;
byte[] footer = null;
if (_state == CompressionState.Header)
{
header = new byte[Zlib.GZIP_HEADER_LENGTH];
header[0] = Zlib.GZIP_HEADER[0];
header[1] = Zlib.GZIP_HEADER[1];
header[2] = Zlib.Z_DEFLATED;
header[3] = 0;
// 3-8 represent time and are set to zero
header[9] = Zlib.OS_CODE;
_crc.Init();
_state = CompressionState.Data;
}
int outputOffset = 0;
byte[] output;
try
{
output = FilterInner(bInput, ref outputOffset, closing);
}
catch
{
_state = CompressionState.Failed;
throw;
}
if (output == null)
{
_state = CompressionState.Failed;
return(TextElement.Null);
}
// input should be read to the end
Debug.Assert(outputOffset == bInput.Length);
_crc.Update(bInput);
if (closing)
{
byte[] crcBytes = _crc.Final();
footer = new byte[Zlib.GZIP_FOOTER_LENGTH];
// well this implementation simply has the hash inverted compared to C implementation
footer[0] = crcBytes[3];
footer[1] = crcBytes[2];
footer[2] = crcBytes[1];
footer[3] = crcBytes[0];
footer[4] = (byte)(_stream.total_in & 0xFF);
footer[5] = (byte)((_stream.total_in >> 8) & 0xFF);
footer[6] = (byte)((_stream.total_in >> 16) & 0xFF);
footer[7] = (byte)((_stream.total_in >> 24) & 0xFF);
_state = CompressionState.Finished;
}
if (header != null || footer != null)
{
int offset = 0;
byte[] appended = new byte[(header != null ? header.Length : 0) + output.Length + (footer != null ? footer.Length : 0)];
if (header != null)
{
Buffer.BlockCopy(header, 0, appended, 0, header.Length);
offset += header.Length;
}
if (output != null && output.Length > 0)
{
Buffer.BlockCopy(output, 0, appended, offset, output.Length);
offset += output.Length;
}
if (footer != null)
{
Buffer.BlockCopy(footer, 0, appended, offset, footer.Length);
}
return(new TextElement(appended));
}
else
{
return(new TextElement(output));
}
}
else
{
Debug.Fail("GzipCompresionFilter expects chunks to be of type PhpBytes.");
return(TextElement.Null);
}
}
public sealed override TextElement /*PhpFilter.*/ Filter(IEncodingProvider enc, TextElement input, bool closing)
{
var @in = new UserFilterBucketBrigade()
{
bucket = input.ToPhpString()
};
var @out = new UserFilterBucketBrigade();
var consumed = new PhpAlias(0L);
switch ((PhpFilters.FilterStatus)filter(@in, @out, consumed, closing))
{
case PhpFilters.FilterStatus.OK:
return(new TextElement(@out.bucket, enc.StringEncoding));
case PhpFilters.FilterStatus.MoreData:
return(TextElement.Empty);
case PhpFilters.FilterStatus.FatalError:
default:
// silently stop feeding this filter
return(TextElement.Null);
}
}
