Cache PureBasic Reference Documentation

Cache

Current Version: 10.1.0

Requires Chilkat Bundle License

Object Creation

obj.i = CkCache::ckCreate()

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

Properties

DebugLogFilePath

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

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:

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

More Information and Examples

Example showing how to use DebugLogFilePath.

LastErrorHtml

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

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.

LastErrorText

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

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.

More Information and Examples

Concept of LastErrorText LastErrorText Standard Information

LastErrorXml

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

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.

LastEtagFetched

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

The ETag of the last item fetched from cache.

LastExpirationFetchedStr

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

Expiration date/time of the last item fetched from cache in RFC822 string format.

LastHitExpired

Declare.i ckLastHitExpired(obj.i) ; (read-only)

1 if the LastExpirationFetched is before the current date/time. Otherwise 0.

LastKeyFetched

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

The key of the last item fetched from cache. (For web pages, the key is typically the canonicalized URL. Otherwise, the key is a unique identifer used to access the cached item.)

LastMethodSuccess

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

Indicate whether the last method call succeeded or failed. A value of 1 indicates success, a value of 0 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 = 1 and failure = 0.
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 1. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

Level

Declare.i ckLevel(obj.i)
Declare setCkLevel(obj.i, value.i)

The number of directory levels in the cache. Possible values are:

0: All cache files are in a single directory (the cache root).

1: Cache files are located in 256 sub-directories numbered 0 .. 255 directly under the cache root.

2: There are two levels of sub-directories under the cache root. The 1st level has 256 sub-directories numbered 0 .. 255 directly under the cache root. The 2nd level allows for up to 256 sub-directories (0..255) under each level-1 directory. Cache files are stored in the leaf directories.

NumRoots

Declare.i ckNumRoots(obj.i) ; (read-only)

The number of root directories composing the cache. A typical multi-root cache would place each root on a separate hard drive.

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 "9.5.0.94"

More Information and Examples

How to get the Chilkat version at runtime.

Methods

AddRoot

Declare ckAddRoot(obj.i, path.s)

Must be called once for each cache root. For example, if the cache is spread across D:\cacheRoot, E:\cacheRoot, and F:\cacheRoot, an application would setup the cache object by calling AddRoot three times -- once with "D:\cacheRoot", once with "E:\cacheRoot", and once with "F:\cacheRoot".

More Information and Examples

Large Persistent Hash Table Stored on Filesystem

DeleteAll

Declare.i ckDeleteAll(obj.i)

Deletes all items in the cache. This method completely clears the cache. All files in the cache are deleted. (If the cache is multi-level, existing sub-directories are not deleted.)

Returns the number of items (i.e. cache files) deleted.

DeleteAllExpired

Declare.i ckDeleteAllExpired(obj.i)

Deletes all expired items from the cache.

Returns the number of items (i.e. cache files) deleted.

DeleteFromCache

Declare.i ckDeleteFromCache(obj.i, key.s)

Deletes a single item from the disk cache. Returns 0 if the item exists in cache but could not be deleted. Otherwise returns 1.

Returns 1 for success, 0 for failure.

DeleteOlderDt

Declare.i ckDeleteOlderDt(obj.i, dateTime.i)

The same as DeleteOlder, except the dateTime is passed as a CkDateTime.

DeleteOlderStr

Declare.i ckDeleteOlderStr(obj.i, dateTimeStr.s)

The same as DeleteOlder, except the dateTimeStr is passed as a date/time in RFC822 format.

FetchBd

Declare.i ckFetchBd(obj.i, key.s, bd.i)

Introduced in version 9.5.0.91

Fetches an item from cache and returns in bd.

The key may be any length and may include any characters. It should uniquely identify the cached item. (No two items in the cache should have the same key.)

Returns 1 for success, 0 for failure.

FetchSb

Declare.i ckFetchSb(obj.i, key.s, sb.i)

Introduced in version 9.5.0.91

Fetches a text item from the cache and returns in sb.

The key may be any length and may include any characters. It should uniquely identify the cached item. (No two items in the cache should have the same key.)

Returns 1 for success, 0 for failure.

FetchText

Declare.s ckFetchText(obj.i, key.s)

Fetches a text item from the cache and returns it's text content.

The key may be any length and may include any characters. It should uniquely identify the cached item. (No two items in the cache should have the same key.)

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

More Information and Examples

Large Persistent Hash Table Stored on Filesystem

GetEtag

Declare.s ckGetEtag(obj.i, key.s)

Returns the eTag for an item in the cache.

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

GetExpirationDt

Declare.i ckGetExpirationDt(obj.i, key.s)

Returns the expiration date/time for an item in the cache as a CkDateTime object.

Returns 0 on failure

GetExpirationStr

Declare.s ckGetExpirationStr(obj.i, url.s)

Returns the expiration date/time for an item in the cache in RFC822 string format.

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

GetFilename

Declare.s ckGetFilename(obj.i, key.s)

Returns the absolute file path of the cache file associated with the key.

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

GetRoot

Declare.s ckGetRoot(obj.i, index.l)

Returns the directory path of the Nth cache root. (Indexing begins at 0.)

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

IsCached

Declare.i ckIsCached(obj.i, key.s)

Returns 1 if the item is found in the cache, otherwise returns 0.

SaveTextDt

Declare.i ckSaveTextDt(obj.i, key.s, expireDateTime.i, eTag.s, itemTextData.s)

The same as SaveText, except the expire date/time is passed as a CkDateTime object.

Returns 1 for success, 0 for failure.

SaveTextNoExpire

Declare.i ckSaveTextNoExpire(obj.i, key.s, eTag.s, itemTextData.s)

Inserts or replaces an text item in the cache with no expiration date/time. The eTag is optional and may be set to a zero-length string. Applications may use it as a place to save additional information about the cached item.

Returns 1 for success, 0 for failure.

More Information and Examples

Large Persistent Hash Table Stored on Filesystem

SaveTextStr

Declare.i ckSaveTextStr(obj.i, key.s, expireDateTime.s, eTag.s, itemTextData.s)

The same as SaveText, except the expire date/time is passed as a string in RFC822 format.

Returns 1 for success, 0 for failure.

UpdateExpirationDt

Declare.i ckUpdateExpirationDt(obj.i, key.s, expireDateTime.i)

The same as UpdateExpiration, except the expireDateTime is passed as a CkDateTime.

Returns 1 for success, 0 for failure.

UpdateExpirationStr

Declare.i ckUpdateExpirationStr(obj.i, key.s, expireDateTime.s)

The same as UpdateExpiration, except the expireDateTime is passed in RFC822 string format.

Returns 1 for success, 0 for failure.