Zstd Component

Properties   Methods   Events   Config Settings   Errors  

TBD.

Syntax

ipworkszip.Zstd

Remarks

TBD

Property List

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The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

Method List

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The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

Event List

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The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

Config Settings

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The following is a list of config settings for the component with short descriptions. Click on the links for further details.

CompressionLevel Property (Zstd Component)

The compression level to use.

Syntax

func (obj *Zstd) CompressionLevel() (int32, error)
func (obj *Zstd) SetCompressionLevel(value int32) error

Default Value

4

Remarks

The compression level to use, from 1 to 6. Higher values will cause the component to compress better; lower values will cause the component to compress faster.

When GetCompressionStream is invoked the stream will be created with the specified compression level. After a stream has been created it is independent of the control, and changing CompressionLevel will have no effect on existing streams.

Data Type

int32

InputData Property (Zstd Component)

Specifies the data to compress or decompress.

Syntax

func (obj *Zstd) InputData() ([]byte, error)
func (obj *Zstd) SetInputData(value []byte) error

Default Value

""

Remarks

This property specifies the data to compress or decompress.

When decompressing this should be set to the compressed data before calling DecompressData or DecompressBlock.

When compressing this should be set to the decompressed data before calling CompressData or CompressBlock.

When performing operations on multiple chunks of data, note that this property is not automatically cleared after each operation.

Data Type

[]byte

OutputData Property (Zstd Component)

The output data after compression or decompression.

Syntax

func (obj *Zstd) OutputData() ([]byte, error)

Default Value

""

Remarks

This property holds the compressed or decompressed data after CompressData or DecompressData is called.

This property is not applicable when calling CompressBlock or DecompressBlock.

This property is read-only.

Data Type

[]byte

CompressBlock Method (Zstd Component)

Compresses a block of data.

Syntax

func (obj *Zstd) CompressBlock(LastBlock bool) error

Remarks

This method compresses the block of data specified by InputData.

The CompressBlock and DecompressBlock methods operate on blocks (chunks) of data. The methods may be used to compress and decompress data as it becomes available.

Note that when using blocks of data the OutputData property is not applicable. Instead data is made available through the CompressedData and DecompressedData events.

If all data is available ahead of time CompressData and DecompressData may be called instead.

Compress Data

Set InputData to the current block to be compressed. Next call CompressBlock to compress the current block. Note that CompressBlock takes a LastBlock parameter. If the block of data is the final block to be compressed set this to True. For all other blocks set this to False.

During compression the CompressedData event will fire with the compressed data. Note that this event may not fire for every call to CompressBlock due to the way the compression algorithm operates. For example:

zipstream.InputDataB = MyDecompressedData; zipstream.CompressBlock(); Data is accumulated inside the CompressedData event: private static void Zipstream_OnCompressedData(object sender, ZipstreamCompressedDataEventArgs e) { DoSomethingWith(e.DataB); }

Note that OutputData is not applicable when compressing block data.

Decompress Data

Set InputData to the current block to be decompressed. Next call DecompressBlock to decompress the current block.

During decompression the DecompressedData event will fire with the decompressed data. Note that this event may not fire for every call to DecompressBlock due to the way the decompression algorithm operates. For example:

zipstream.InputDataB = MyCompressedData; zipstream.DecompressBlock(); Data is accumulated inside the DecompressedData event: private static void Zipstream_OnDecompressedData(object sender, ZipstreamDecompressedDataEventArgs e) { DoSomethingWith(e.DataB); }

Note that OutputData is not applicable when decompressing block data.

CompressData Method (Zstd Component)

Compresses the specified data.

Syntax

func (obj *Zstd) CompressData() error

Remarks

This method compresses the data specified by InputData. After calling this method OutputData holds the compressed data.

The CompressData and DecompressData methods operate on the complete blob of data. The entire compressed or decompressed data must be set to InputData before calling either method.

To compress and decompress data in blocks (chunks) see CompressBlock and DecompressBlock.

Compress Data

Set InputData to the decompressed data. This should be the entire data to be compressed. Next call CompressData. After compression OutputData will hold the compressed data. For example:

zipstream.InputDataB = MyDecompressedData; zipstream.CompressData(); MyCompressedData = zipstream.OutputDataB;

In addition to OutputData, the compressed data may also be accumulated within the CompressedData event.

Decompress Data

Set InputData to the compressed data. This should be the entire data to be decompressed. Next call DecompressData. After decompression OutputData will hold the decompressed data. For example:

zipstream.InputDataB = MyCompressedData; zipstream.DecompressData(); MyDecompressedData = zipstream.OutputDataB;

In addition to OutputData, the compressed data may also be accumulated within the DecompressedData event.

Config Method (Zstd Component)

Sets or retrieves a configuration setting.

Syntax

func (obj *Zstd) Config(ConfigurationString string) (string, error)

Remarks

Config is a generic method available in every struct. It is used to set and retrieve configuration settings for the struct.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the struct, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

DecompressBlock Method (Zstd Component)

Decompresses a block of data.

Syntax

func (obj *Zstd) DecompressBlock() error

Remarks

This method decompresses the block of data specified by InputData.

The CompressBlock and DecompressBlock methods operate on blocks (chunks) of data. The methods may be used to compress and decompress data as it becomes available.

Note that when using blocks of data the OutputData property is not applicable. Instead data is made available through the CompressedData and DecompressedData events.

If all data is available ahead of time CompressData and DecompressData may be called instead.

Compress Data

Set InputData to the current block to be compressed. Next call CompressBlock to compress the current block. Note that CompressBlock takes a LastBlock parameter. If the block of data is the final block to be compressed set this to True. For all other blocks set this to False.

During compression the CompressedData event will fire with the compressed data. Note that this event may not fire for every call to CompressBlock due to the way the compression algorithm operates. For example:

zipstream.InputDataB = MyDecompressedData; zipstream.CompressBlock(); Data is accumulated inside the CompressedData event: private static void Zipstream_OnCompressedData(object sender, ZipstreamCompressedDataEventArgs e) { DoSomethingWith(e.DataB); }

Note that OutputData is not applicable when compressing block data.

Decompress Data

Set InputData to the current block to be decompressed. Next call DecompressBlock to decompress the current block.

During decompression the DecompressedData event will fire with the decompressed data. Note that this event may not fire for every call to DecompressBlock due to the way the decompression algorithm operates. For example:

zipstream.InputDataB = MyCompressedData; zipstream.DecompressBlock(); Data is accumulated inside the DecompressedData event: private static void Zipstream_OnDecompressedData(object sender, ZipstreamDecompressedDataEventArgs e) { DoSomethingWith(e.DataB); }

Note that OutputData is not applicable when decompressing block data.

DecompressData Method (Zstd Component)

Decompresses the specified data.

Syntax

func (obj *Zstd) DecompressData() error

Remarks

This method decompresses the data specified by InputData. After calling this method OutputData holds the decompressed data.

The CompressData and DecompressData methods operate on the complete blob of data. The entire compressed or decompressed data must be set to InputData before calling either method.

To compress and decompress data in blocks (chunks) see CompressBlock and DecompressBlock.

Compress Data

Set InputData to the decompressed data. This should be the entire data to be compressed. Next call CompressData. After compression OutputData will hold the compressed data. For example:

zipstream.InputDataB = MyDecompressedData; zipstream.CompressData(); MyCompressedData = zipstream.OutputDataB;

In addition to OutputData, the compressed data may also be accumulated within the CompressedData event.

Decompress Data

Set InputData to the compressed data. This should be the entire data to be decompressed. Next call DecompressData. After decompression OutputData will hold the decompressed data. For example:

zipstream.InputDataB = MyCompressedData; zipstream.DecompressData(); MyDecompressedData = zipstream.OutputDataB;

In addition to OutputData, the compressed data may also be accumulated within the DecompressedData event.

Reset Method (Zstd Component)

Resets the class.

Syntax

func (obj *Zstd) Reset() error

Remarks

Reset resets the state of the struct. All properties will be set to their default values, and any files open will be closed.

CompressedData Event (Zstd Component)

This event fires with compressed data.

Syntax

// ZstdCompressedDataEventArgs carries the Zstd CompressedData event's parameters.
type ZstdCompressedDataEventArgs struct {...}

func (args *ZstdCompressedDataEventArgs) Data() []byte
// ZstdCompressedDataEvent defines the signature of the Zstd CompressedData event's handler function.
type ZstdCompressedDataEvent func(sender *Zstd, args *ZstdCompressedDataEventArgs)

func (obj *Zstd) GetOnCompressedDataHandler() ZstdCompressedDataEvent
func (obj *Zstd) SetOnCompressedDataHandler(handlerFunc ZstdCompressedDataEvent)

Remarks

The CompressedData event fires as compressed data is available when CompressData or CompressBlock is called. This may fire one or more times when data is compressed.

Data holds the current block of compressed data.

DecompressedData Event (Zstd Component)

This event fires with decompressed data.

Syntax

// ZstdDecompressedDataEventArgs carries the Zstd DecompressedData event's parameters.
type ZstdDecompressedDataEventArgs struct {...}

func (args *ZstdDecompressedDataEventArgs) Data() []byte
// ZstdDecompressedDataEvent defines the signature of the Zstd DecompressedData event's handler function.
type ZstdDecompressedDataEvent func(sender *Zstd, args *ZstdDecompressedDataEventArgs)

func (obj *Zstd) GetOnDecompressedDataHandler() ZstdDecompressedDataEvent
func (obj *Zstd) SetOnDecompressedDataHandler(handlerFunc ZstdDecompressedDataEvent)

Remarks

The DecompressedData event fires as compressed data is available when DecompressData or DecompressBlock is called. This may fire one or more times as data is decompressed.

Data holds the current block of decompressed data.

Error Event (Zstd Component)

Information about errors during data delivery.

Syntax

// ZstdErrorEventArgs carries the Zstd Error event's parameters.
type ZstdErrorEventArgs struct {...}

func (args *ZstdErrorEventArgs) ErrorCode() int32
func (args *ZstdErrorEventArgs) Description() string
// ZstdErrorEvent defines the signature of the Zstd Error event's handler function.
type ZstdErrorEvent func(sender *Zstd, args *ZstdErrorEventArgs)

func (obj *Zstd) GetOnErrorHandler() ZstdErrorEvent
func (obj *Zstd) SetOnErrorHandler(handlerFunc ZstdErrorEvent)

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the struct fails with an error.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Config Settings (Zstd Component)

The struct accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the struct, access to these internal properties is provided through the Config method.

No configuration settings defined.

Base Config Settings

Trappable Errors (Zstd Component)

Note that the streams returned by GetCompressionStream and GetDecompressionStream will throw standard IOExceptions in case of error.

ZipStream Errors