ZipCrc PureBasic Reference Documentation

ZipCrc

Current Version: 10.1.2

Requires Chilkat Bundle License

Calculate a Zip CRC checksum for a file or in-memory data.

Object Creation

obj.i = CkZipCrc::ckCreate()

; Make sure to dispose of the object when finished like this:
CkZipCrc::ckDispose(obj);

Properties

DebugLogFilePath

Declare.s ckDebugLogFilePath(obj.i)
Declare setCkDebugLogFilePath(obj.i, value.s)

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.

More Information and Examples

Example showing how to use DebugLogFilePath.

LastErrorHtml

Declare.s ckLastErrorHtml(obj.i) ; (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.

LastErrorText

Declare.s ckLastErrorText(obj.i) ; (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.

More Information and Examples

Concept of LastErrorText LastErrorText Standard Information

LastErrorXml

Declare.s ckLastErrorXml(obj.i) ; (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.

LastMethodSuccess

Declare.i ckLastMethodSuccess(obj.i)
Declare setCkLastMethodSuccess(obj.i, value.i)

Indicates the success or failure of the most recent method call: 1 means success, 0 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.

VerboseLogging

Declare.i ckVerboseLogging(obj.i)
Declare setCkVerboseLogging(obj.i, value.i)

If set to 1, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is 0. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

Version

Declare.s ckVersion(obj.i) ; (read-only)

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

More Information and Examples

How to get the Chilkat version at runtime.

Methods

BeginStream

Declare ckBeginStream(obj.i)

Provides a way to calculate a CRC by streaming the data a chunk at a time. An application would start by calling BeginStream. Then it would add data by calling MoreData for each additional chunk. After the last chunk has been processed, the EndStream method is called to return the CRC.

CrcBd

Declare.i ckCrcBd(obj.i, bd.i)

Introduced in version 9.5.0.75

Calculates a CRC32 for the bytes contained in bd.

CrcSb

Declare.i ckCrcSb(obj.i, sb.i, charset.s)

Introduced in version 9.5.0.75

Calculates a CRC32 for the string contained in sb. The charset is the byte representation to be used for the sb when calculating the CRC32. It can be utf-8, utf-16, windows-1252, iso-8859-1, or any of the character encodings (charsets) listed at the link below.

CrcString

Declare.i ckCrcString(obj.i, str.s, charset.s)

Introduced in version 9.5.0.75

Calculates a CRC32 for a string. The charset is the byte representation to be used for the str when calculating the CRC32. It can be utf-8, utf-16, windows-1252, iso-8859-1, or any of the character encodings (charsets) listed at the link below.

EndStream

Declare.i ckEndStream(obj.i)

Finalizes and returns the Zip CRC value calculated by calling BeginStream followed by multiple calls to MoreData.

FileCrc

Declare.i ckFileCrc(obj.i, path.s)

Calculates the CRC32 of a file. The data contained in the file is streamed for the calculation to keep the memory footprint small and constant. Returns the CRC32 of the file.

More Information and Examples

Compute CRC32 of a File

FileCrcAsync ⁽¹⁾

Declare.i ckFileCrcAsync(obj.i, path.s)

Creates an asynchronous task to call the FileCrc method with the arguments provided.

Returns 0 on failure

LoadTaskCaller

Declare.i ckLoadTaskCaller(obj.i, task.i)

Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns 1 for success, 0 for failure.

ToHex

Declare.s ckToHex(obj.i, crc.l)

Converts a 32-bit integer to a hex string.

Returns an empty string on failure. Use the LastMethodSuccess property to check for success.