Gzip DataFlex Reference Documentation

Gzip

GZip compression component.

Object Creation

Handle hoGzip
Get Create(RefClass(cComChilkatGzip)) to hoGzip

Properties

Function ComAbortCurrent Returns Boolean
Procedure Set ComAbortCurrent Boolean value

Introduced in version 9.5.0.58

When set to True, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to False when the next method is called. When the abort occurs, this property is reset to False. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

Function ComComment Returns String
Procedure Set ComComment String value

Specifies an optional comment string that can be embedded within the .gz when any Compress* method is called.

Function ComCompressionLevel Returns Integer
Procedure Set ComCompressionLevel Integer value

Introduced in version 9.5.0.50

The compression level to be used when compressing. The default is 6, which is the typical value used for zip utility programs when compressing data. The compression level may range from 0 (no compression) to 9 (the most compression). The benefits of trying to increase compression may not be worth the added expense in compression time. In many cases (which is data dependent), the improvement in compression is minimal while the increase in computation time is significant.

Function ComDebugLogFilePath Returns String
Procedure Set ComDebugLogFilePath String value

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

Function ComExtraData Returns Variant
Procedure Set ComExtraData Variant value

Optional extra-data that can be included within a .gz when a Compress* method is called.

Function ComFilename Returns String
Procedure Set ComFilename String value

The filename that is embedded within the .gz during any Compress* method call. When extracting from a .gz using applications such as WinZip, this will be the filename that is created.

Function ComLastBinaryResult Returns Variant

Introduced in version 9.5.0.52

The binary data returned by the last (binary data returning) method called. Only available if Chilkat.Global.KeepBinaryResult is set to True. This provides a means for obtaining large varbinary results in the SQL Server environment (where limitations exist in getting large amounts of data returned by method calls, but where temp tables can be used for binary properties).

Function ComLastErrorHtml Returns String

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Function ComLastErrorText Returns String

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Concept of LastErrorText

LastErrorText Standard Information

Function ComLastErrorXml Returns String

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Function ComLastMethodSuccess Returns Boolean
Procedure Set ComLastMethodSuccess Boolean value

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of True indicates success, a value of False indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = True and failure = False.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to True. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

Function ComLastMod Returns DateTime
Procedure Set ComLastMod DateTime value

This property is deprecated. It will be removed in a future version.

The last-modification date/time to be embedded within the .gz when a Compress* method is called. By default, the current system date/time is used.

Function ComLastModStr Returns String
Procedure Set ComLastModStr String value

The same as the LastMod property, but allows the date/time to be get/set in RFC822 string format.

Function ComLastStringResult Returns String

Introduced in version 9.5.0.52

The string return value of the last (string returning) method called. Only available if Chilkat.Global.KeepStringResult is set to True. This provides a means for obtaining large string results in the SQL Server environment (where limitations exist in getting long strings returned by method calls, but where temp tables can be used for string properties).

Long Strings Returned by ActiveX Methods in SQL Server

Function ComLastStringResultLen Returns Integer

Introduced in version 9.5.0.53

The length, in characters, of the string contained in the LastStringResult property.

Function ComUseCurrentDate Returns Boolean
Procedure Set ComUseCurrentDate Boolean value

If set to True, the file produced by an Uncompress* method will use the current date/time for the last-modification date instead of the date/time found within the Gzip format.

Function ComVerboseLogging Returns Boolean
Procedure Set ComVerboseLogging Boolean value

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.

Function ComVersion Returns String

Version of the component/library, such as "9.5.0.63"

Methods

Function ComCompressBd cComChilkatBinData binDat Returns Boolean

Introduced in version 9.5.0.67

In-place gzip the contents of binDat.

Returns True for success, False for failure.

Gzip Compress In Memory and Base64 Encode

Function ComCompressBdAsync cComChilkatBinData binDat Returns cComChilkatTask

Introduced in version 9.5.0.67

Creates an asynchronous task to call the CompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComCompressFile String inFilename String destPath Returns Boolean

Compresses a file to create a GZip compressed file (.gz).

Returns True for success, False for failure.

Function ComCompressFileAsync String inFilename String destPath Returns cComChilkatTask

Creates an asynchronous task to call the CompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComCompressFile2 String inFilename String embeddedFilename String destPath Returns Boolean

Compresses a file to create a GZip compressed file (.gz). inFilename is the actual filename on disk. embeddedFilename is the filename to be embedded in the .gz such that when it is un-gzipped, this is the name of the file that will be created.

Returns True for success, False for failure.

Function ComCompressFile2Async String inFilename String embeddedFilename String destPath Returns cComChilkatTask

Creates an asynchronous task to call the CompressFile2 method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComCompressFileToMem String inFilename Returns Variant

Gzip compresses a file to an in-memory image of a .gz file.

Returns null on failure

Function ComCompressFileToMemAsync String inFilename Returns cComChilkatTask

Creates an asynchronous task to call the CompressFileToMem method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComCompressMemory Variant inData Returns Variant

Compresses in-memory data to an in-memory image of a .gz file.

Returns null on failure

Function ComCompressMemoryAsync Variant inData Returns cComChilkatTask

Creates an asynchronous task to call the CompressMemory method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComCompressMemToFile Variant inData String destPath Returns Boolean

Gzip compresses and creates a .gz file from in-memory data.

Returns True for success, False for failure.

Function ComCompressMemToFileAsync Variant inData String destPath Returns cComChilkatTask

Creates an asynchronous task to call the CompressMemToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComCompressString String inStr String destCharset Returns Variant

Gzip compresses a string and writes the output to a byte array. The string is first converted to the charset specified by destCharset. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns null on failure

Full List of Charset Names

Function ComCompressStringAsync String inStr String destCharset Returns cComChilkatTask

Creates an asynchronous task to call the CompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComCompressStringENC String inStr String charset String encoding Returns String

The same as CompressString, except the binary output is returned in encoded string form according to the encoding. The encoding can be any of the following: "Base64", "modBase64", "Base32", "UU", "QP" (for quoted-printable), "URL" (for url-encoding), "Hex", "Q", "B", "url_oath", "url_rfc1738", "url_rfc2396", and "url_rfc3986".

Returns null on failure

Function ComCompressStringToFile String inStr String destCharset String destPath Returns Boolean

Gzip compresses a string and writes the output to a .gz compressed file. The string is first converted to the charset specified by destCharset. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns True for success, False for failure.

Full List of Charset Names

Function ComCompressStringToFileAsync String inStr String destCharset String destPath Returns cComChilkatTask

Creates an asynchronous task to call the CompressStringToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComDecode String encodedStr String encoding Returns Variant

Decodes an encoded string and returns the original data. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns null on failure

Function ComDeflateStringENC String inString String charsetName String outputEncoding Returns String

Provides the ability to use the zip/gzip's deflate algorithm directly to compress a string. Internal to this method, inString is first converted to the charset specified by charsetName. The data is then compressed using the deflate compression algorithm. The binary output is then encoded according to outputEncoding. Possible values for outputEncoding are "hex", "base64", "url", and "quoted-printable".

Note: The output of this method is compressed data with no Gzip file format. Use the Compress* methods to produce Gzip file format output.

Returns null on failure

Full List of Charset Names

Function ComEncode Variant byteData String encoding Returns String

Encodes binary data to a printable string. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns null on failure

Function ComExamineFile String inGzFilename Returns Boolean

Determines if the inGzFilename is a Gzip formatted file. Returns True if it is a Gzip formatted file, otherwise returns False.

Function ComExamineMemory Variant inGzData Returns Boolean

Determines if the in-memory bytes (inGzData) contain a Gzip formatted file. Returns True if it is Gzip format, otherwise returns False.

Function ComGetDt Returns cComCkDateTime

Gets the last-modification date/time to be embedded within the .gz.

Returns null on failure

Function ComInflateStringENC String inString String convertFromCharset String inputEncoding Returns String

This the reverse of DeflateStringENC.

The input string is first decoded according to inputEncoding. (Possible values for inputEncoding are "hex", "base64", "url", and "quoted-printable".) The compressed data is then inflated, and the result is then converted from convertFromCharset (if necessary) to return a string.

Returns null on failure

Function ComIsUnlocked Returns Boolean

Returns True if the component has been unlocked.

Function ComReadFile String path Returns Variant

Reads a binary file into memory and returns the byte array. Note: This method does not parse a Gzip, it is only a convenience method for reading a binary file into memory.

Returns null on failure

Function ComSetDt cComCkDateTime dt Returns Boolean

Sets the last-modification date/time to be embedded within the .gz when a Compress* method is called. If not explicitly set, the current system date/time is used.

Returns True for success, False for failure.

Function ComUncompressBd cComChilkatBinData binDat Returns Boolean

Introduced in version 9.5.0.67

In-place ungzip the contents of binDat.

Returns True for success, False for failure.

Function ComUncompressBdAsync cComChilkatBinData binDat Returns cComChilkatTask

Introduced in version 9.5.0.67

Creates an asynchronous task to call the UncompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComUncompressFile String srcPath String destPath Returns Boolean

Un-Gzips a .gz file. The output filename is specified by the 2nd argument and not by the filename embedded within the .gz.

Returns True for success, False for failure.

GZip Decompress File

Function ComUncompressFileAsync String srcPath String destPath Returns cComChilkatTask

Creates an asynchronous task to call the UncompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComUncompressFileToMem String inFilename Returns Variant

Un-Gzips a .gz file directly to memory.

Returns null on failure

Function ComUncompressFileToMemAsync String inFilename Returns cComChilkatTask

Creates an asynchronous task to call the UncompressFileToMem method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComUncompressFileToString String gzFilename String charset Returns String

Uncompresses a .gz file that contains a text file. The contents of the text file are returned as a string. The character encoding of the text file is specified by charset. Typical charsets are "iso-8859-1", "utf-8", "windows-1252", "shift_JIS", "big5", etc.

Returns null on failure

List of Valid Charsets

Function ComUncompressFileToStringAsync String gzFilename String charset Returns cComChilkatTask

Creates an asynchronous task to call the UncompressFileToString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComUncompressMemory Variant inData Returns Variant

Un-Gzips from an in-memory image of a .gz file directly into memory.

Returns null on failure

Function ComUncompressMemoryAsync Variant inData Returns cComChilkatTask

Creates an asynchronous task to call the UncompressMemory method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComUncompressMemToFile Variant inData String destPath Returns Boolean

Un-Gzips from an in-memory image of a .gz file to a file.

Returns True for success, False for failure.

Function ComUncompressMemToFileAsync Variant inData String destPath Returns cComChilkatTask

Creates an asynchronous task to call the UncompressMemToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComUncompressString Variant inData String inCharset Returns String

The reverse of CompressString.

The bytes in inData are uncompressed, then converted from inCharset (if necessary) to return a string.

Returns null on failure

Full List of Charset Names

Function ComUncompressStringAsync Variant inData String inCharset Returns cComChilkatTask

Creates an asynchronous task to call the UncompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComUncompressStringENC String inStr String charset String encoding Returns String

The same as UncompressString, except the compressed data is provided in encoded string form based on the value of encoding. The encoding can be "Base64", "modBase64", "Base32", "UU", "QP" (for quoted-printable), "URL" (for url-encoding), "Hex", "Q", "B", "url_oath", "url_rfc1738", "url_rfc2396", and "url_rfc3986".

Returns null on failure

Function ComUnlockComponent String unlockCode Returns Boolean

Unlocks the component allowing for the full functionality to be used.

Returns True for success, False for failure.

Diagnosing UnlockComponent Problems

UnlockComponent LastErrorText shows exact string passed to it.

Verify UnlockComponent Success w/ Purchased Unlock Code

LastErrorText Standard Information

Function ComUnTarGz String tgzFilename String destDir Boolean bNoAbsolute Returns Boolean

Unpacks a .tar.gz file. The ungzip and untar occur in streaming mode. There are no temporary files and the memory footprint is constant (and small) while untarring. bNoAbsolute may be True or False. A value of True protects from untarring to absolute paths. (For example, imagine the trouble if the tar contains files with absolute paths beginning with /Windows/system32)

Returns True for success, False for failure.

Function ComUnTarGzAsync String tgzFilename String destDir Boolean bNoAbsolute Returns cComChilkatTask

Creates an asynchronous task to call the UnTarGz method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

How to Run an Asynchronous Task

Function ComWriteFile String path Variant binaryData Returns Boolean

A convenience method for writing a binary byte array to a file.

Returns True for success, False for failure.

Function ComXfdlToXml String xfldData Returns String

Converts base64-gzip .xfdl data to a decompressed XML string. The xfldData contains the base64 data. This method returns the decoded/decompressed XML string.

Returns null on failure