Compression CkPython Reference Documentation

CkCompression

Current Version: 11.0.0

Implements the Bzip2, Deflate, and LZW compression algorithms.

Object Creation

obj = chilkat.CkCompression()

Properties

Algorithm
# strVal is a string
# ckStr is a CkString
compression.get_Algorithm(ckStr);
strVal = compression.algorithm();
compression.put_Algorithm(strVal);

Specifies the compression algorithm: "deflate", "zlib", "bzip2", or "lzw". Note that "ppmd" is deprecated and should not be used. It was only available for 32-bit systems and specifically used the "J" variant. Please transition to one of the recommended algorithms.

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Charset
# strVal is a string
# ckStr is a CkString
compression.get_Charset(ckStr);
strVal = compression.charset();
compression.put_Charset(strVal);

Specifies the character encoding for compressing or decompressing strings. Options include utf-8 (default), windows-1252, Shift_JIS, iso-8859-2, and others.

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DebugLogFilePath
# strVal is a string
# ckStr is a CkString
compression.get_DebugLogFilePath(ckStr);
strVal = compression.debugLogFilePath();
compression.put_DebugLogFilePath(strVal);

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

More Information and Examples
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DeflateLevel
# intVal is an integer
intVal = compression.get_DeflateLevel();
compression.put_DeflateLevel(intVal);
Introduced in version 9.5.0.73

This property allows for customization of the compression level for the "deflate" and "zlib" compression algoirthms. ("zlib" is just the deflate algorithm with a zlib header.) A value of 0 = no compression, while 9 = maximum compression. The default is 6.

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EncodingMode
# strVal is a string
# ckStr is a CkString
compression.get_EncodingMode(ckStr);
strVal = compression.encodingMode();
compression.put_EncodingMode(strVal);

Controls the encoding expected by methods ending in "ENC", such as CompressBytesENC. Valid values are "base64", "hex", "url", and "quoted-printable". Compression methods ending in ENC return the binary compressed data as an encoded string using this encoding. Decompress methods expect the input string to be this encoding.

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FirstChunk
# boolVal is a boolean
boolVal = compression.get_FirstChunk();
compression.put_FirstChunk(boolVal);
Introduced in version 11.0.0

This property applies to FirstChunk and LastChunk aware compression and decompression methods. It signifies that the data being compressed is the first of multiple chunks.

The default value is True.

When both FirstChunk and LastChunk, it means the entire amount of data to be compressed or decompressed is presented in a single call.

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LastChunk
# boolVal is a boolean
boolVal = compression.get_LastChunk();
compression.put_LastChunk(boolVal);
Introduced in version 11.0.0

This property applies to FirstChunk and LastChunk aware compression and decompression methods. It signifies that the data being compressed is the last of multiple chunks.

The default value is True.

When both FirstChunk and LastChunk, it means the entire amount of data to be compressed or decompressed is presented in a single call.

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LastErrorHtml
# strVal is a string
# ckStr is a CkString
compression.get_LastErrorHtml(ckStr);
strVal = compression.lastErrorHtml();

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
# strVal is a string
# ckStr is a CkString
compression.get_LastErrorText(ckStr);
strVal = compression.lastErrorText();

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
# strVal is a string
# ckStr is a CkString
compression.get_LastErrorXml(ckStr);
strVal = compression.lastErrorXml();

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
# boolVal is a boolean
boolVal = compression.get_LastMethodSuccess();
compression.put_LastMethodSuccess(boolVal);

Indicates the success or failure of the most recent method call: True means success, False means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages.

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UncommonOptions
# strVal is a string
# ckStr is a CkString
compression.get_UncommonOptions(ckStr);
strVal = compression.uncommonOptions();
compression.put_UncommonOptions(strVal);
Introduced in version 11.0.0

This is a catch-all property to be used for uncommon needs. This property defaults to the empty string and should typically remain empty.

Can be set to a list of the following comma separated keywords:

  • Crypt2CompressHdr - Duplicates the compression and decompression as implemented in the deprecated and removed Crypt2 compression functions.

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VerboseLogging
# boolVal is a boolean
boolVal = compression.get_VerboseLogging();
compression.put_VerboseLogging(boolVal);

If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
# strVal is a string
# ckStr is a CkString
compression.get_Version(ckStr);
strVal = compression.version();

Version of the component/library, such as "10.1.0"

More Information and Examples
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Methods

CompressBd
# bd is a CkBinData
status = compression.CompressBd(bd);
Introduced in version 9.5.0.66

Compresses the data contained in bd. This method is not FirstChunk/LastChunk aware.

Returns True for success, False for failure.

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CompressBdAsync (1)
# returns a CkTask
# bd is a CkBinData
ret_task = compression.CompressBdAsync(bd);
Introduced in version 9.5.0.66

Creates an asynchronous task to call the CompressBd method with the arguments provided.

Returns None on failure

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CompressBd2
# bdIn is a CkBinData
# bdOut is a CkBinData
status = compression.CompressBd2(bdIn, bdOut);
Introduced in version 11.0.0

This method compresses the data in bdIn without modifying it and appends the compressed data to bdOut. It is also FirstChunk/LastChunk aware.

Returns True for success, False for failure.

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CompressBd2Async (1)
# returns a CkTask
# bdIn is a CkBinData
# bdOut is a CkBinData
ret_task = compression.CompressBd2Async(bdIn, bdOut);
Introduced in version 11.0.0

Creates an asynchronous task to call the CompressBd2 method with the arguments provided.

Returns None on failure

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CompressBytes Deprecated
# data is a CkByteData
# outData is a CkByteData (output)
status = compression.CompressBytes(data, outData);

Compresses byte data.

This method is FirstChunk/LastChunk aware.

Returns True for success, False for failure.

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CompressBytesAsync Deprecated (1)
# returns a CkTask
# data is a CkByteData
ret_task = compression.CompressBytesAsync(data);

Creates an asynchronous task to call the CompressBytes method with the arguments provided.

Returns None on failure

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CompressEncryptFile
# cryptParams is a CkJsonObject
# srcPath is a string
# destPath is a string
status = compression.CompressEncryptFile(cryptParams, srcPath, destPath);
Introduced in version 9.5.0.99

Performs file-to-file compression and encryption. Files of any size may be compressed because the file is compressed and encrypted internally in streaming mode.

Returns True for success, False for failure.

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CompressEncryptFileAsync (1)
# returns a CkTask
# cryptParams is a CkJsonObject
# srcPath is a string
# destPath is a string
ret_task = compression.CompressEncryptFileAsync(cryptParams, srcPath, destPath);
Introduced in version 9.5.0.99

Creates an asynchronous task to call the CompressEncryptFile method with the arguments provided.

Returns None on failure

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CompressFile
# srcPath is a string
# destPath is a string
status = compression.CompressFile(srcPath, destPath);

Performs file-to-file compression. Files of any size may be compressed because the file is compressed internally in streaming mode.

Returns True for success, False for failure.

More Information and Examples
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CompressFileAsync (1)
# returns a CkTask
# srcPath is a string
# destPath is a string
ret_task = compression.CompressFileAsync(srcPath, destPath);

Creates an asynchronous task to call the CompressFile method with the arguments provided.

Returns None on failure

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CompressSb
# sb is a CkStringBuilder
# binData is a CkBinData
status = compression.CompressSb(sb, binData);
Introduced in version 9.5.0.73

Compresses the contents of sb and appends the compressed bytes to binData.

This method is FirstChunk/LastChunk aware.

Returns True for success, False for failure.

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CompressSbAsync (1)
# returns a CkTask
# sb is a CkStringBuilder
# binData is a CkBinData
ret_task = compression.CompressSbAsync(sb, binData);
Introduced in version 9.5.0.73

Creates an asynchronous task to call the CompressSb method with the arguments provided.

Returns None on failure

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CompressStr Deprecated
# str is a string
# bd is a CkBinData
status = compression.CompressStr(str, bd);
Introduced in version 11.0.0

Compresses a string and appends to bd. The byte representation (character encoding) of the actual bytes to be compressed is determined by the Charset property. This method is FirstChunk / LastChunk aware.

Returns True for success, False for failure.

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CompressStrAsync Deprecated (1)
# returns a CkTask
# str is a string
# bd is a CkBinData
ret_task = compression.CompressStrAsync(str, bd);
Introduced in version 11.0.0

Creates an asynchronous task to call the CompressStr method with the arguments provided.

Returns None on failure

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CompressStream
# strm is a CkStream
status = compression.CompressStream(strm);
Introduced in version 9.5.0.56

Compresses a stream. Internally, the strm's source is read, compressed, and the compressed data written to the strm's sink. It does this in streaming fashion. Extremely large or even infinite streams can be compressed with stable ungrowing memory usage.

Returns True for success, False for failure.

More Information and Examples
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CompressStreamAsync (1)
# returns a CkTask
# strm is a CkStream
ret_task = compression.CompressStreamAsync(strm);
Introduced in version 9.5.0.56

Creates an asynchronous task to call the CompressStream method with the arguments provided.

Returns None on failure

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CompressString Deprecated
# str is a string
# outData is a CkByteData (output)
status = compression.CompressString(str, outData);

Compresses a string.

This method is FirstChunk/LastChunk aware.

Returns True for success, False for failure.

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CompressStringAsync Deprecated (1)
# returns a CkTask
# str is a string
ret_task = compression.CompressStringAsync(str);

Creates an asynchronous task to call the CompressString method with the arguments provided.

Returns None on failure

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CompressStringENC
# str is a string
# outStr is a CkString (output)
status = compression.CompressStringENC(str, outStr);
retStr = compression.compressStringENC(str);

Compresses a string and returns the compressed data encoded to a string. The output encoding (hex, base64, etc.) is determined by the EncodingMode property setting.

Returns True for success, False for failure.

More Information and Examples
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CompressStringENCAsync (1)
# returns a CkTask
# str is a string
ret_task = compression.CompressStringENCAsync(str);

Creates an asynchronous task to call the CompressStringENC method with the arguments provided.

Returns None on failure

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DecompressBd
# bd is a CkBinData
status = compression.DecompressBd(bd);
Introduced in version 9.5.0.66

Decompresses the data contained in bd. This method is not FirstChunk/LastChunk aware.

Returns True for success, False for failure.

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DecompressBdAsync (1)
# returns a CkTask
# bd is a CkBinData
ret_task = compression.DecompressBdAsync(bd);
Introduced in version 9.5.0.66

Creates an asynchronous task to call the DecompressBd method with the arguments provided.

Returns None on failure

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DecompressBd2
# bdIn is a CkBinData
# bdOut is a CkBinData
status = compression.DecompressBd2(bdIn, bdOut);
Introduced in version 11.0.0

This method decompresses the data in bdIn without modifying it and appends the decompressed data to bdOut. It is also FirstChunk/LastChunk aware.

Returns True for success, False for failure.

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DecompressBd2Async (1)
# returns a CkTask
# bdIn is a CkBinData
# bdOut is a CkBinData
ret_task = compression.DecompressBd2Async(bdIn, bdOut);
Introduced in version 11.0.0

Creates an asynchronous task to call the DecompressBd2 method with the arguments provided.

Returns None on failure

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DecompressBytes Deprecated
# data is a CkByteData
# outData is a CkByteData (output)
status = compression.DecompressBytes(data, outData);

This method decompresses bytes.

This method is FirstChunk/LastChunk aware.

Returns True for success, False for failure.

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DecompressBytesAsync Deprecated (1)
# returns a CkTask
# data is a CkByteData
ret_task = compression.DecompressBytesAsync(data);

Creates an asynchronous task to call the DecompressBytes method with the arguments provided.

Returns None on failure

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DecompressFile
# srcPath is a string
# destPath is a string
status = compression.DecompressFile(srcPath, destPath);

Performs file-to-file decompression (the opposite of CompressFile). Internally the file is decompressed in streaming mode which allows files of any size to be decompressed.

Returns True for success, False for failure.

More Information and Examples
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DecompressFileAsync (1)
# returns a CkTask
# srcPath is a string
# destPath is a string
ret_task = compression.DecompressFileAsync(srcPath, destPath);

Creates an asynchronous task to call the DecompressFile method with the arguments provided.

Returns None on failure

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DecompressSb
# binData is a CkBinData
# sb is a CkStringBuilder
status = compression.DecompressSb(binData, sb);
Introduced in version 9.5.0.73

Decompresses the contents of binData and appends the decompressed string to sb.

This method is FirstChunk/LastChunk aware.

Returns True for success, False for failure.

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DecompressSbAsync (1)
# returns a CkTask
# binData is a CkBinData
# sb is a CkStringBuilder
ret_task = compression.DecompressSbAsync(binData, sb);
Introduced in version 9.5.0.73

Creates an asynchronous task to call the DecompressSb method with the arguments provided.

Returns None on failure

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DecompressStream
# strm is a CkStream
status = compression.DecompressStream(strm);
Introduced in version 9.5.0.56

Decompresses a stream. Internally, the strm's source is read, decompressed, and the decompressed data written to the strm's sink. It does this in streaming fashion. Extremely large or even infinite streams can be decompressed with stable ungrowing memory usage.

Returns True for success, False for failure.

More Information and Examples
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DecompressStreamAsync (1)
# returns a CkTask
# strm is a CkStream
ret_task = compression.DecompressStreamAsync(strm);
Introduced in version 9.5.0.56

Creates an asynchronous task to call the DecompressStream method with the arguments provided.

Returns None on failure

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DecryptDecompressFile
# cryptParams is a CkJsonObject
# srcPath is a string
# destPath is a string
status = compression.DecryptDecompressFile(cryptParams, srcPath, destPath);
Introduced in version 9.5.0.99

Performs file-to-file decryption and decompression.

Returns True for success, False for failure.

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DecryptDecompressFileAsync (1)
# returns a CkTask
# cryptParams is a CkJsonObject
# srcPath is a string
# destPath is a string
ret_task = compression.DecryptDecompressFileAsync(cryptParams, srcPath, destPath);
Introduced in version 9.5.0.99

Creates an asynchronous task to call the DecryptDecompressFile method with the arguments provided.

Returns None on failure

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LoadTaskCaller
# task is a CkTask
status = compression.LoadTaskCaller(task);
Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns True for success, False for failure.

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Deprecated

BeginCompressBytes
# data is a CkByteData
# outData is a CkByteData (output)
status = compression.BeginCompressBytes(data, outData);
This method is deprecated.

Large amounts of binary byte data may be compressed in chunks by first calling BeginCompressBytes, followed by 0 or more calls to MoreCompressedBytes, and ending with a final call to EndCompressBytes. Each call returns 0 or more bytes of compressed data which may be output to a compressed data stream (such as a file, socket, etc.).

Returns True for success, False for failure.

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BeginCompressBytesENC
# data is a CkByteData
# outStr is a CkString (output)
status = compression.BeginCompressBytesENC(data, outStr);
retStr = compression.beginCompressBytesENC(data);
This method is deprecated.

Large amounts of binary byte data may be compressed in chunks by first calling BeginCompressBytesENC, followed by 0 or more calls to MoreCompressedBytesENC, and ending with a final call to EndCompressBytesENC. Each call returns 0 or more characters of compressed data (encoded as a string according to the EncodingMode property setting) which may be output to a compressed data stream (such as a file, socket, etc.).

Returns True for success, False for failure.

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BeginCompressString
# str is a string
# outData is a CkByteData (output)
status = compression.BeginCompressString(str, outData);
This method is deprecated.

Large amounts of string data may be compressed in chunks by first calling BeginCompressString, followed by 0 or more calls to MoreCompressedString, and ending with a final call to EndCompressString. Each call returns 0 or more bytes of compressed data which may be output to a compressed data stream (such as a file, socket, etc.).

Returns True for success, False for failure.

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BeginCompressStringENC
# str is a string
# outStr is a CkString (output)
status = compression.BeginCompressStringENC(str, outStr);
retStr = compression.beginCompressStringENC(str);
This method is deprecated.

Large amounts of string data may be compressed in chunks by first calling BeginCompressStringENC, followed by 0 or more calls to MoreCompressedStringENC, and ending with a final call to EndCompressStringENC. Each call returns 0 or more characters of compressed data (encoded as a string according to the EncodingMode property setting) which may be output to a compressed data stream (such as a file, socket, etc.).

Returns True for success, False for failure.

More Information and Examples
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BeginDecompressBytes
# data is a CkByteData
# outData is a CkByteData (output)
status = compression.BeginDecompressBytes(data, outData);
This method is deprecated.

A compressed data stream may be decompressed in chunks by first calling BeginDecompressBytes, followed by 0 or more calls to MoreDecompressedBytes, and ending with a final call to EndDecompressBytes. Each call returns 0 or more bytes of decompressed data.

Returns True for success, False for failure.

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BeginDecompressBytesENC
# str is a string
# outData is a CkByteData (output)
status = compression.BeginDecompressBytesENC(str, outData);
This method is deprecated.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

A compressed data stream may be decompressed in chunks by first calling BeginDecompressBytesENC, followed by 0 or more calls to MoreDecompressedBytesENC, and ending with a final call to EndDecompressBytesENC. Each call returns 0 or more bytes of decompressed data.

Returns True for success, False for failure.

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BeginDecompressString
# data is a CkByteData
# outStr is a CkString (output)
status = compression.BeginDecompressString(data, outStr);
retStr = compression.beginDecompressString(data);
This method is deprecated.

A compressed data stream may be decompressed in chunks by first calling BeginDecompressString, followed by 0 or more calls to MoreDecompressedString, and ending with a final call to EndDecompressString. Each call returns 0 or more characters of decompressed text.

Returns True for success, False for failure.

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BeginDecompressStringENC
# str is a string
# outStr is a CkString (output)
status = compression.BeginDecompressStringENC(str, outStr);
retStr = compression.beginDecompressStringENC(str);
This method is deprecated.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

A compressed data stream may be decompressed in chunks by first calling BeginDecompressStringENC, followed by 0 or more calls to MoreDecompressedStringENC, and ending with a final call to EndDecompressStringENC. Each call returns 0 or more characters of decompressed text.

Returns True for success, False for failure.

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EndCompressBytes
# outData is a CkByteData (output)
status = compression.EndCompressBytes(outData);
This method is deprecated.

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressBytes)

Returns True for success, False for failure.

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EndCompressBytesENC
# outStr is a CkString (output)
status = compression.EndCompressBytesENC(outStr);
retStr = compression.endCompressBytesENC();
This method is deprecated.

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressBytesENC)

Returns True for success, False for failure.

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EndCompressString
# outData is a CkByteData (output)
status = compression.EndCompressString(outData);
This method is deprecated.

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressString)

Returns True for success, False for failure.

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EndCompressStringENC
# outStr is a CkString (output)
status = compression.EndCompressStringENC(outStr);
retStr = compression.endCompressStringENC();
This method is deprecated.

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressStringENC)

Returns True for success, False for failure.

More Information and Examples
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EndDecompressBytes
# outData is a CkByteData (output)
status = compression.EndDecompressBytes(outData);
This method is deprecated.

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

(See BeginDecompressBytes)

Returns True for success, False for failure.

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EndDecompressBytesENC
# outData is a CkByteData (output)
status = compression.EndDecompressBytesENC(outData);
This method is deprecated.

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressBytesENC)

Returns True for success, False for failure.

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EndDecompressString
# outStr is a CkString (output)
status = compression.EndDecompressString(outStr);
retStr = compression.endDecompressString();
This method is deprecated.

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

(See BeginDecompressString)

Returns True for success, False for failure.

More Information and Examples
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EndDecompressStringENC
# outStr is a CkString (output)
status = compression.EndDecompressStringENC(outStr);
retStr = compression.endDecompressStringENC();
This method is deprecated.

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressStringENC)

Returns True for success, False for failure.

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MoreCompressBytes
# data is a CkByteData
# outData is a CkByteData (output)
status = compression.MoreCompressBytes(data, outData);
This method is deprecated.

(See BeginCompressBytes)

Returns True for success, False for failure.

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MoreCompressBytesENC
# data is a CkByteData
# outStr is a CkString (output)
status = compression.MoreCompressBytesENC(data, outStr);
retStr = compression.moreCompressBytesENC(data);
This method is deprecated.

(See BeginCompressBytesENC)

Returns True for success, False for failure.

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MoreCompressString
# str is a string
# outData is a CkByteData (output)
status = compression.MoreCompressString(str, outData);
This method is deprecated.

(See BeginCompressString)

Returns True for success, False for failure.

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MoreCompressStringENC
# str is a string
# outStr is a CkString (output)
status = compression.MoreCompressStringENC(str, outStr);
retStr = compression.moreCompressStringENC(str);
This method is deprecated.

(See BeginCompressStringENC)

Returns True for success, False for failure.

More Information and Examples
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MoreDecompressBytes
# data is a CkByteData
# outData is a CkByteData (output)
status = compression.MoreDecompressBytes(data, outData);
This method is deprecated.

(See BeginDecompressBytes)

Returns True for success, False for failure.

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MoreDecompressBytesENC
# str is a string
# outData is a CkByteData (output)
status = compression.MoreDecompressBytesENC(str, outData);
This method is deprecated.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressBytesENC)

Returns True for success, False for failure.

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MoreDecompressString
# data is a CkByteData
# outStr is a CkString (output)
status = compression.MoreDecompressString(data, outStr);
retStr = compression.moreDecompressString(data);
This method is deprecated.

(See BeginDecompressString)

Returns True for success, False for failure.

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MoreDecompressStringENC
# str is a string
# outStr is a CkString (output)
status = compression.MoreDecompressStringENC(str, outStr);
retStr = compression.moreDecompressStringENC(str);
This method is deprecated.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressStringENC)

Returns True for success, False for failure.

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