ZipCrc Unicode C Reference Documentation

ZipCrc

Current Version: 9.5.0.79

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

Create/Dispose

HCkZipCrcW instance = CkZipCrcW_Create();
// ...
CkZipCrcW_Dispose(instance);
HCkZipCrcW CkZipCrcW_Create(void);

Creates an instance of the HCkZipCrcW object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.

void CkZipCrcW_Dispose(HCkZipCrcW handle);

Objects created by calling CkZipCrcW_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkZipCrcW_Dispose.

Callback Functions

Callback Functions introduced in Chilkat v9.5.0.56
void CkZipCrcW_setAbortCheck(HCkZipCrcW cHandle, BOOL (*fnAbortCheck)(void));

Provides the opportunity for a method call to be aborted. If TRUE is returned, the operation in progress is aborted. Return FALSE to allow the current method call to continue. This callback function is called periodically based on the value of the HeartbeatMs property. (If HeartbeatMs is 0, then no callbacks are made.) As an example, to make 5 AbortCheck callbacks per second, set the HeartbeatMs property equal to 200.

void CkZipCrcW_setPercentDone(HCkZipCrcW cHandle, BOOL (*fnPercentDone)(int pctDone));

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This callback is only called when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For methods that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

This callback counts as an AbortCheck callback, and takes the place of the AbortCheck event when it fires.

The return value indicates whether the method call should be aborted, or whether it should proceed. Return TRUE to abort, and FALSE to proceed.

void CkZipCrcW_setProgressInfo(HCkZipCrcW cHandle, void (*fnProgressInfo)(const wchar_t *name, const wchar_t *value));

This is a general callback that provides name/value information about what is happening at certain points during a method call. To see the information provided in ProgressInfo callbacks, if any, write code to handle this event and log the name/value pairs. Most are self-explanatory.

void CkZipCrcW_setTaskCompleted(HCkZipCrcW cHandle, void (*fnTaskCompleted)(HCkTaskW hTask));

Called in the background thread when an asynchronous task completes. (Note: When an async method is running, all callbacks are in the background thread.)

Properties

DebugLogFilePath
void CkZipCrcW_getDebugLogFilePath(HCkZipCrcW cHandle, HCkString retval);
void CkZipCrcW_putDebugLogFilePath(HCkZipCrcW cHandle, const wchar_t *newVal);
const wchar_t *CkZipCrcW_debugLogFilePath(HCkZipCrcW cHandle);

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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LastErrorHtml
void CkZipCrcW_getLastErrorHtml(HCkZipCrcW cHandle, HCkString retval);
const wchar_t *CkZipCrcW_lastErrorHtml(HCkZipCrcW cHandle);

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
void CkZipCrcW_getLastErrorText(HCkZipCrcW cHandle, HCkString retval);
const wchar_t *CkZipCrcW_lastErrorText(HCkZipCrcW cHandle);

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
void CkZipCrcW_getLastErrorXml(HCkZipCrcW cHandle, HCkString retval);
const wchar_t *CkZipCrcW_lastErrorXml(HCkZipCrcW cHandle);

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
BOOL CkZipCrcW_getLastMethodSuccess(HCkZipCrcW cHandle);
void CkZipCrcW_putLastMethodSuccess(HCkZipCrcW cHandle, BOOL newVal);
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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VerboseLogging
BOOL CkZipCrcW_getVerboseLogging(HCkZipCrcW cHandle);
void CkZipCrcW_putVerboseLogging(HCkZipCrcW cHandle, BOOL newVal);

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
void CkZipCrcW_getVersion(HCkZipCrcW cHandle, HCkString retval);
const wchar_t *CkZipCrcW_version(HCkZipCrcW cHandle);

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

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Methods

BeginStream
void CkZipCrcW_BeginStream(HCkZipCrcW cHandle);

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.

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CalculateCrc
unsigned long CkZipCrcW_CalculateCrc(HCkZipCrcW cHandle, const unsigned char * data);

Calculates a 32-bit CRC for in-memory byte data. This is the 32-bit CRC that would be found in a Zip file header if a file containing the data was added to a zip archive. Returns the CRC32 of the data.

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CrcBd
unsigned long CkZipCrcW_CrcBd(HCkZipCrcW cHandle, HCkBinDataW bd);
Introduced in version 9.5.0.75

Calculates a CRC32 for the bytes contained in bd.

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CrcSb
unsigned long CkZipCrcW_CrcSb(HCkZipCrcW cHandle, HCkStringBuilderW sb, const wchar_t *charset);
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.

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CrcString
unsigned long CkZipCrcW_CrcString(HCkZipCrcW cHandle, const wchar_t *str, const wchar_t *charset);
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.

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EndStream
unsigned long CkZipCrcW_EndStream(HCkZipCrcW cHandle);

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

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FileCrc
unsigned long CkZipCrcW_FileCrc(HCkZipCrcW cHandle, const wchar_t *path);

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.

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FileCrcAsync (1)
HCkTaskW CkZipCrcW_FileCrcAsync(HCkZipCrcW cHandle, const wchar_t *path);

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

Returns NULL on failure

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MoreData
void CkZipCrcW_MoreData(HCkZipCrcW cHandle, const unsigned char * data);

Adds additional data to the CRC currently being calculated. (See BeginStream for more information.)

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SaveLastError
BOOL CkZipCrcW_SaveLastError(HCkZipCrcW cHandle, const wchar_t *path);

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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ToHex
BOOL CkZipCrcW_ToHex(HCkZipCrcW cHandle, int crc, const wchar_t *outStr);
const wchar_t *CkZipCrcW_toHex(HCkZipCrcW cHandle, int crc);

Converts a 32-bit integer to a hex string.

Returns TRUE for success, FALSE for failure.

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