Compression

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.

This property specifies the character encoding used to represent text as bytes for compression and decompression. By default, it uses the computer's ANSI charset, such as Windows-1252 for locales like the United States, United Kingdom, Western Europe, Australia, and New Zealand.

Most applications are advised to set this property to UTF-8. Chilkat plans to change its default to UTF-8 in a future major version to align with current standards. The current default of ANSI stems from a time when UTF-8 was not widely adopted.

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.

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.

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.

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 are set to true, it means the entire amount of data to be compressed or decompressed is presented in a single call.

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 are set to true, it means the entire amount of data to be compressed or decompressed is presented in a single call.

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.

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.

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.

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. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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.

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.

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

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

Returns true for success, false for failure.

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.

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.

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.

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.

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.

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. This method is NOT FirstChunk/LastChunk aware.

Returns null on failure

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

Returns true for success, false for failure.

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.

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.

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.

The opposite of CompressStringENC. encodedCompressedData contains the compressed data as an encoded string (hex, base64, etc) as specified by the EncodingMode property setting. This method is NOT FirstChunk/LastChunk aware.

Returns null on failure

Performs file-to-file decryption and decompression.

Returns true for success, false for failure.