Gzip Go Reference Documentation

Gzip

Current Version: 9.5.0.82

GZip compression component.

Object Creation

gz := chilkat.NewGzip()
...
gz.DisposeGzip()

Properties

AbortCurrent
func (gz *Gzip) AbortCurrent() bool
func (gz *Gzip) SetAbortCurrent(b bool)
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.)

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Comment
func (gz *Gzip) Comment() string
func (gz *Gzip) SetComment(s string)

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

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CompressionLevel
func (gz *Gzip) CompressionLevel() int
func (gz *Gzip) SetCompressionLevel(v int)
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.

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DebugLogFilePath
func (gz *Gzip) DebugLogFilePath() string
func (gz *Gzip) SetDebugLogFilePath(s string)

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.

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ExtraData
func (gz *Gzip) ExtraData() []byte
func (gz *Gzip) SetExtraData(byteData []byte)

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

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Filename
func (gz *Gzip) Filename() string
func (gz *Gzip) SetFilename(s string)

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.

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LastErrorHtml
func (gz *Gzip) LastErrorHtml() 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.

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LastErrorText
func (gz *Gzip) LastErrorText() 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.

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LastErrorXml
func (gz *Gzip) LastErrorXml() 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.

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LastMethodSuccess
func (gz *Gzip) LastMethodSuccess() bool
func (gz *Gzip) SetLastMethodSuccess(b bool)
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.

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LastModStr
func (gz *Gzip) LastModStr() string
func (gz *Gzip) SetLastModStr(s string)

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

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UseCurrentDate
func (gz *Gzip) UseCurrentDate() bool
func (gz *Gzip) SetUseCurrentDate(b bool)

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.

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VerboseLogging
func (gz *Gzip) VerboseLogging() bool
func (gz *Gzip) SetVerboseLogging(b bool)

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
func (gz *Gzip) Version() string

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

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Methods

CompressBd
func (gz *Gzip) CompressBd(binDat *BinData) bool
Introduced in version 9.5.0.67

In-place gzip the contents of binDat.

Returns true for success, false for failure.

More Information and Examples
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CompressBdAsync (1)
func (gz *Gzip) CompressBdAsync(binDat *BinData) *Task
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 nil on failure

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CompressFile
func (gz *Gzip) CompressFile(inFilename string, destPath string) bool

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

Returns true for success, false for failure.

More Information and Examples
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CompressFileAsync (1)
func (gz *Gzip) CompressFileAsync(inFilename string, destPath string) *Task

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 nil on failure

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CompressFile2
func (gz *Gzip) CompressFile2(inFilename string, embeddedFilename string, destPath string) bool

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.

More Information and Examples
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CompressFile2Async (1)
func (gz *Gzip) CompressFile2Async(inFilename string, embeddedFilename string, destPath string) *Task

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 nil on failure

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CompressFileToMem
func (gz *Gzip) CompressFileToMem(inFilename string) []byte

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

Note: There is a 4GB size limitation. The compressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns nil on failure

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CompressFileToMemAsync (1)
func (gz *Gzip) CompressFileToMemAsync(inFilename string) *Task

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 nil on failure

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CompressMemory
func (gz *Gzip) CompressMemory(inData []byte) []byte

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

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns nil on failure

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CompressMemoryAsync (1)
func (gz *Gzip) CompressMemoryAsync(inData []byte) *Task

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 nil on failure

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CompressMemToFile
func (gz *Gzip) CompressMemToFile(inData []byte, destPath string) bool

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

Returns true for success, false for failure.

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CompressMemToFileAsync (1)
func (gz *Gzip) CompressMemToFileAsync(inData []byte, destPath string) *Task

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 nil on failure

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CompressString
func (gz *Gzip) CompressString(inStr string, destCharset string) []byte

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 nil on failure

More Information and Examples
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CompressStringAsync (1)
func (gz *Gzip) CompressStringAsync(inStr string, destCharset string) *Task

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 nil on failure

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CompressStringENC
func (gz *Gzip) CompressStringENC(inStr string, charset string, encoding string) *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 nil on failure

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CompressStringToFile
func (gz *Gzip) CompressStringToFile(inStr string, destCharset string, destPath string) bool

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.

More Information and Examples
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CompressStringToFileAsync (1)
func (gz *Gzip) CompressStringToFileAsync(inStr string, destCharset string, destPath string) *Task

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 nil on failure

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Decode
func (gz *Gzip) Decode(encodedStr string, encoding string) []byte

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 nil on failure

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DeflateStringENC
func (gz *Gzip) DeflateStringENC(inString string, charsetName string, outputEncoding string) *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 nil on failure

More Information and Examples
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Encode
func (gz *Gzip) Encode(byteData []byte, encoding string) *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 nil on failure

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ExamineFile
func (gz *Gzip) ExamineFile(inGzFilename string) bool

Determines if the inGzFilename is a Gzip formatted file. Returns true if it is a Gzip formatted file, otherwise returns false.

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ExamineMemory
func (gz *Gzip) ExamineMemory(inGzData []byte) bool

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

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GetDt
func (gz *Gzip) GetDt() *CkDateTime

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

Returns nil on failure

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InflateStringENC
func (gz *Gzip) InflateStringENC(inString string, convertFromCharset string, inputEncoding string) *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 nil on failure

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IsUnlocked
func (gz *Gzip) IsUnlocked() bool

Returns true if the component has been unlocked.

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LoadTaskCaller
func (gz *Gzip) LoadTaskCaller(task *Task) bool
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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ReadFile
func (gz *Gzip) ReadFile(path string) []byte

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 nil on failure

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SaveLastError
func (gz *Gzip) SaveLastError(path string) bool

Saves the last-error information (the contents of LastErrorXml) to an XML formatted file.

Returns true for success, false for failure.

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SetDt
func (gz *Gzip) SetDt(dt *CkDateTime) bool

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.

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UncompressBd
func (gz *Gzip) UncompressBd(binDat *BinData) bool
Introduced in version 9.5.0.67

In-place ungzip the contents of binDat.

Returns true for success, false for failure.

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UncompressBdAsync (1)
func (gz *Gzip) UncompressBdAsync(binDat *BinData) *Task
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 nil on failure

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UncompressFile
func (gz *Gzip) UncompressFile(srcPath string, destPath string) bool

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.

More Information and Examples
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UncompressFileAsync (1)
func (gz *Gzip) UncompressFileAsync(srcPath string, destPath string) *Task

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 nil on failure

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UncompressFileToMem
func (gz *Gzip) UncompressFileToMem(inFilename string) []byte

Un-Gzips a .gz file directly to memory.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns nil on failure

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UncompressFileToMemAsync (1)
func (gz *Gzip) UncompressFileToMemAsync(inFilename string) *Task

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 nil on failure

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UncompressFileToString
func (gz *Gzip) UncompressFileToString(gzFilename string, charset string) *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 nil on failure

More Information and Examples
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UncompressFileToStringAsync (1)
func (gz *Gzip) UncompressFileToStringAsync(gzFilename string, charset string) *Task

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 nil on failure

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UncompressMemory
func (gz *Gzip) UncompressMemory(inData []byte) []byte

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

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns nil on failure

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UncompressMemoryAsync (1)
func (gz *Gzip) UncompressMemoryAsync(inData []byte) *Task

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 nil on failure

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UncompressMemToFile
func (gz *Gzip) UncompressMemToFile(inData []byte, destPath string) bool

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

Returns true for success, false for failure.

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UncompressMemToFileAsync (1)
func (gz *Gzip) UncompressMemToFileAsync(inData []byte, destPath string) *Task

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 nil on failure

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UncompressString
func (gz *Gzip) UncompressString(inData []byte, inCharset string) *string

The reverse of CompressString.

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

Returns nil on failure

More Information and Examples
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UncompressStringAsync (1)
func (gz *Gzip) UncompressStringAsync(inData []byte, inCharset string) *Task

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 nil on failure

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UncompressStringENC
func (gz *Gzip) UncompressStringENC(inStr string, charset string, encoding string) *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 nil on failure

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UnlockComponent
func (gz *Gzip) UnlockComponent(unlockCode string) bool

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

Returns true for success, false for failure.

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UnTarGz
func (gz *Gzip) UnTarGz(tgzFilename string, destDir string, bNoAbsolute bool) bool

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.

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UnTarGzAsync (1)
func (gz *Gzip) UnTarGzAsync(tgzFilename string, destDir string, bNoAbsolute bool) *Task

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 nil on failure

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WriteFile
func (gz *Gzip) WriteFile(path string, binaryData []byte) bool

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

Returns true for success, false for failure.

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XfdlToXml
func (gz *Gzip) XfdlToXml(xfldData string) *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 nil on failure

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