Compression Node.js Reference Documentation
Compression
Current Version: 10.1.0
Implements the Bzip2, Deflate, and LZW compression algorithms.
Object Creation
var obj = new chilkat.Compression();
Properties
Algorithm
· string
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.
topCharset
· string
Only applies to methods that compress or decompress strings. This specifies the character encoding that the string should be converted to before compression. Many programming languages use Unicode (2 bytes per char) for representing characters. This property allows for the string to be converted to a 1-byte per char encoding prior to compression.
topDebugLogFilePath
· string
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.
DeflateLevel
· integer
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.
topEncodingMode
· string
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.
topLastErrorHtml
· string, read-only
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.
topLastErrorText
· string, read-only
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.
LastErrorXml
· string, read-only
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.
topLastMethodSuccess
· boolean
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.
topVerboseLogging
· boolean
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.
topVersion
· string, read-only
Methods
BeginCompressBytes
· Returns a Buffer.
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 null on failure
topBeginCompressBytesAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the BeginCompressBytes method with the arguments provided.
Returns null on failure
topBeginCompressBytesENC
· Returns a String.
· data Buffer
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 null on failure
topBeginCompressBytesENCAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the BeginCompressBytesENC method with the arguments provided.
Returns null on failure
topBeginCompressString
· Returns a Buffer.
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 null on failure
topBeginCompressStringAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the BeginCompressString method with the arguments provided.
Returns null on failure
topBeginCompressStringENC
· Returns a String.
· str String
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 null on failure
BeginCompressStringENCAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the BeginCompressStringENC method with the arguments provided.
Returns null on failure
topBeginDecompressBytes
· Returns a Buffer.
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 null on failure
topBeginDecompressBytesAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the BeginDecompressBytes method with the arguments provided.
Returns null on failure
topBeginDecompressBytesENC
· Returns a Buffer.
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 null on failure
topBeginDecompressBytesENCAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the BeginDecompressBytesENC method with the arguments provided.
Returns null on failure
topBeginDecompressString
· Returns a String.
· data Buffer
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 null on failure
topBeginDecompressStringAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the BeginDecompressString method with the arguments provided.
Returns null on failure
topBeginDecompressStringENC
· Returns a String.
· str String
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 null on failure
topBeginDecompressStringENCAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the BeginDecompressStringENC method with the arguments provided.
Returns null on failure
topCompressBd
· Returns Boolean (true for success, false for failure).
· binData BinData
Compresses the data contained in a BinData object.
Returns true for success, false for failure.
CompressBdAsync (1)
· Returns a Task
· binData BinData
Creates an asynchronous task to call the CompressBd method with the arguments provided.
Returns null on failure
topCompressBytes
· Returns a Buffer.
CompressBytesAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the CompressBytes method with the arguments provided.
Returns null on failure
topCompressBytesENC
· Returns a String.
· data Buffer
Compresses bytes and returns the compressed data encoded to a string. The encoding (hex, base64, etc.) is determined by the EncodingMode property setting.
Returns null on failure
topCompressBytesENCAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the CompressBytesENC method with the arguments provided.
Returns null on failure
topCompressEncryptFile
· Returns Boolean (true for success, false for failure).
· cryptParams JsonObject
· srcPath String
· destPath String
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.
CompressEncryptFileAsync (1)
· Returns a Task
· cryptParams JsonObject
· srcPath String
· destPath String
Creates an asynchronous task to call the CompressEncryptFile method with the arguments provided.
Returns null on failure
topCompressFile
· Returns Boolean (true for success, false for failure).
· srcPath String
· destPath String
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.
CompressFileAsync (1)
· Returns a Task
· srcPath String
· destPath String
Creates an asynchronous task to call the CompressFile method with the arguments provided.
Returns null on failure
topCompressSb
· Returns Boolean (true for success, false for failure).
· sb StringBuilder
· binData BinData
Compresses the contents of sb and appends the compressed bytes to binData.
Returns true for success, false for failure.
topCompressSbAsync (1)
· Returns a Task
· sb StringBuilder
· binData BinData
Creates an asynchronous task to call the CompressSb method with the arguments provided.
Returns null on failure
topCompressStream
· Returns Boolean (true for success, false for failure).
· strm Stream
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.
CompressStreamAsync (1)
· Returns a Task
· strm Stream
Creates an asynchronous task to call the CompressStream method with the arguments provided.
Returns null on failure
topCompressString
· Returns a Buffer.
CompressStringAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the CompressString method with the arguments provided.
Returns null on failure
topCompressStringENC
· Returns a String.
· str String
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 null on failure
CompressStringENCAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the CompressStringENC method with the arguments provided.
Returns null on failure
topDecompressBd
· Returns Boolean (true for success, false for failure).
· binData BinData
Decompresses the data contained in a BinData object.
Returns true for success, false for failure.
DecompressBdAsync (1)
· Returns a Task
· binData BinData
Creates an asynchronous task to call the DecompressBd method with the arguments provided.
Returns null on failure
topDecompressBytes
· Returns a Buffer.
DecompressBytesAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the DecompressBytes method with the arguments provided.
Returns null on failure
topDecompressBytesENC
· Returns a Buffer.
The opposite of CompressBytesENC. encodedCompressedData contains the compressed data as an encoded string (hex, base64, etc) as specified by the EncodingMode property setting.
Returns null on failure
topDecompressBytesENCAsync (1)
· Returns a Task
· encodedCompressedData String
Creates an asynchronous task to call the DecompressBytesENC method with the arguments provided.
Returns null on failure
topDecompressFile
· Returns Boolean (true for success, false for failure).
· srcPath String
· destPath String
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.
DecompressFileAsync (1)
· Returns a Task
· srcPath String
· destPath String
Creates an asynchronous task to call the DecompressFile method with the arguments provided.
Returns null on failure
topDecompressSb
· Returns Boolean (true for success, false for failure).
· binData BinData
· sb StringBuilder
Decompresses the contents of binData and appends the decompressed string to sb.
Returns true for success, false for failure.
topDecompressSbAsync (1)
· Returns a Task
· binData BinData
· sb StringBuilder
Creates an asynchronous task to call the DecompressSb method with the arguments provided.
Returns null on failure
topDecompressStream
· Returns Boolean (true for success, false for failure).
· strm Stream
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.
DecompressStreamAsync (1)
· Returns a Task
· strm Stream
Creates an asynchronous task to call the DecompressStream method with the arguments provided.
Returns null on failure
topDecompressString
· Returns a String.
· data Buffer
DecompressStringAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the DecompressString method with the arguments provided.
Returns null on failure
topDecompressStringENC
· Returns a String.
· encodedCompressedData String
The opposite of CompressStringENC. encodedCompressedData contains the compressed data as an encoded string (hex, base64, etc) as specified by the EncodingMode property setting.
Returns null on failure
DecompressStringENCAsync (1)
· Returns a Task
· encodedCompressedData String
Creates an asynchronous task to call the DecompressStringENC method with the arguments provided.
Returns null on failure
topDecryptDecompressFile
· Returns Boolean (true for success, false for failure).
· cryptParams JsonObject
· srcPath String
· destPath String
Performs file-to-file decryption and decompression.
Returns true for success, false for failure.
DecryptDecompressFileAsync (1)
· Returns a Task
· cryptParams JsonObject
· srcPath String
· destPath String
Creates an asynchronous task to call the DecryptDecompressFile method with the arguments provided.
Returns null on failure
topEndCompressBytes
· Returns a Buffer.
Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.
(See BeginCompressBytes)
Returns null on failure
topEndCompressBytesAsync (1)
· Returns a Task
Creates an asynchronous task to call the EndCompressBytes method with the arguments provided.
Returns null on failure
topEndCompressBytesENC
· Returns a String.
Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.
(See BeginCompressBytesENC)
Returns null on failure
topEndCompressBytesENCAsync (1)
· Returns a Task
Creates an asynchronous task to call the EndCompressBytesENC method with the arguments provided.
Returns null on failure
topEndCompressString
· Returns a Buffer.
Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.
(See BeginCompressString)
Returns null on failure
topEndCompressStringAsync (1)
· Returns a Task
Creates an asynchronous task to call the EndCompressString method with the arguments provided.
Returns null on failure
topEndCompressStringENC
· Returns a String.
Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.
(See BeginCompressStringENC)
Returns null on failure
EndCompressStringENCAsync (1)
· Returns a Task
Creates an asynchronous task to call the EndCompressStringENC method with the arguments provided.
Returns null on failure
topEndDecompressBytes
· Returns a Buffer.
Called to finalize the decompression stream and return any remaining (buffered) decompressed data.
(See BeginDecompressBytes)
Returns null on failure
topEndDecompressBytesAsync (1)
· Returns a Task
Creates an asynchronous task to call the EndDecompressBytes method with the arguments provided.
Returns null on failure
topEndDecompressBytesENC
· Returns a Buffer.
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 null on failure
topEndDecompressBytesENCAsync (1)
· Returns a Task
Creates an asynchronous task to call the EndDecompressBytesENC method with the arguments provided.
Returns null on failure
topEndDecompressString
· Returns a String.
Called to finalize the decompression stream and return any remaining (buffered) decompressed data.
(See BeginDecompressString)
Returns null on failure
EndDecompressStringAsync (1)
· Returns a Task
Creates an asynchronous task to call the EndDecompressString method with the arguments provided.
Returns null on failure
topEndDecompressStringENC
· Returns a String.
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 null on failure
topEndDecompressStringENCAsync (1)
· Returns a Task
Creates an asynchronous task to call the EndDecompressStringENC method with the arguments provided.
Returns null on failure
topLoadTaskCaller
· Returns Boolean (true for success, false for failure).
· task Task
MoreCompressBytes
· Returns a Buffer.
MoreCompressBytesAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the MoreCompressBytes method with the arguments provided.
Returns null on failure
topMoreCompressBytesENC
· Returns a String.
· data Buffer
MoreCompressBytesENCAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the MoreCompressBytesENC method with the arguments provided.
Returns null on failure
topMoreCompressString
· Returns a Buffer.
MoreCompressStringAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the MoreCompressString method with the arguments provided.
Returns null on failure
topMoreCompressStringENC
· Returns a String.
· str String
MoreCompressStringENCAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the MoreCompressStringENC method with the arguments provided.
Returns null on failure
topMoreDecompressBytes
· Returns a Buffer.
MoreDecompressBytesAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the MoreDecompressBytes method with the arguments provided.
Returns null on failure
topMoreDecompressBytesENC
· Returns a Buffer.
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 null on failure
topMoreDecompressBytesENCAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the MoreDecompressBytesENC method with the arguments provided.
Returns null on failure
topMoreDecompressString
· Returns a String.
· data Buffer
MoreDecompressStringAsync (1)
· Returns a Task
· data Buffer
Creates an asynchronous task to call the MoreDecompressString method with the arguments provided.
Returns null on failure
topMoreDecompressStringENC
· Returns a String.
· str String
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 null on failure
topMoreDecompressStringENCAsync (1)
· Returns a Task
· str String
Creates an asynchronous task to call the MoreDecompressStringENC method with the arguments provided.
Returns null on failure
top