Cache C Reference Documentation
Cache
Current Version: 10.0.0
Create/Dispose
HCkCache instance = CkCache_Create(); // ... CkCache_Dispose(instance);
Creates an instance of the HCkCache object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.
Objects created by calling CkCache_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 CkCache_Dispose.
Properties
DebugLogFilePath
void CkCache_putDebugLogFilePath(HCkCache cHandle, const char *newVal);
const char *CkCache_debugLogFilePath(HCkCache 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:
- 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.
LastErrorHtml
const char *CkCache_lastErrorHtml(HCkCache 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.
topLastErrorText
const char *CkCache_lastErrorText(HCkCache 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.
LastErrorXml
const char *CkCache_lastErrorXml(HCkCache 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.
topLastEtagFetched
const char *CkCache_lastEtagFetched(HCkCache cHandle);
The ETag of the last item fetched from cache.
topLastExpirationFetchedStr
const char *CkCache_lastExpirationFetchedStr(HCkCache cHandle);
Expiration date/time of the last item fetched from cache in RFC822 string format.
topLastHitExpired
TRUE if the LastExpirationFetched is before the current date/time. Otherwise FALSE.
topLastKeyFetched
const char *CkCache_lastKeyFetched(HCkCache cHandle);
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.)
topLastMethodSuccess
void CkCache_putLastMethodSuccess(HCkCache cHandle, BOOL newVal);
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.
topLevel
void CkCache_putLevel(HCkCache cHandle, int newVal);
The number of directory levels in the cache. Possible values are:
0: All cache files are in a single directory (the cache root).top
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
The number of root directories composing the cache. A typical multi-root cache would place each root on a separate hard drive.
topUtf8
void CkCache_putUtf8(HCkCache cHandle, BOOL newVal);
When set to TRUE, all "const char *" arguments are interpreted as utf-8 strings. If set to FALSE (the default), then "const char *" arguments are interpreted as ANSI strings. Also, when set to TRUE, and Chilkat method returning a "const char *" is returning the utf-8 representation. If set to FALSE, all "const char *" return values are ANSI strings.
topVerboseLogging
void CkCache_putVerboseLogging(HCkCache 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.
topVersion
const char *CkCache_version(HCkCache cHandle);
Methods
AddRoot
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".
DeleteAll
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.
topDeleteAllExpired
Deletes all expired items from the cache.
Returns the number of items (i.e. cache files) deleted.
topDeleteFromCache
Deletes a single item from the disk cache. Returns FALSE if the item exists in cache but could not be deleted. Otherwise returns TRUE.
Returns TRUE for success, FALSE for failure.
topDeleteOlderDt
The same as DeleteOlder, except the dateTime is passed as a CkDateTime.
topDeleteOlderStr
The same as DeleteOlder, except the dateTimeStr is passed as a date/time in RFC822 format.
topFetchBd
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 TRUE for success, FALSE for failure.
topFetchFromCache
Fetches an item from cache.
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 TRUE for success, FALSE for failure.
FetchSb
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 TRUE for success, FALSE for failure.
topFetchText
const char *CkCache_fetchText(HCkCache cHandle, const char *key);
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 TRUE for success, FALSE for failure.
GetEtag
const char *CkCache_getEtag(HCkCache cHandle, const char *key);
GetExpirationDt
Returns the expiration date/time for an item in the cache as a CkDateTime object.
Returns NULL on failure
topGetExpirationStr
const char *CkCache_getExpirationStr(HCkCache cHandle, const char *url);
Returns the expiration date/time for an item in the cache in RFC822 string format.
Returns TRUE for success, FALSE for failure.
topGetFilename
const char *CkCache_getFilename(HCkCache cHandle, const char *key);
Returns the absolute file path of the cache file associated with the key.
Returns TRUE for success, FALSE for failure.
topGetRoot
const char *CkCache_getRoot(HCkCache cHandle, int index);
Returns the directory path of the Nth cache root. (Indexing begins at 0.)
Returns TRUE for success, FALSE for failure.
topIsCached
Returns TRUE if the item is found in the cache, otherwise returns FALSE.
topSaveTextDt
The same as SaveText, except the expire date/time is passed as a CkDateTime object.
Returns TRUE for success, FALSE for failure.
topSaveTextNoExpire
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 TRUE for success, FALSE for failure.
SaveTextStr
The same as SaveText, except the expire date/time is passed as a string in RFC822 format.
Returns TRUE for success, FALSE for failure.
topSaveToCacheDt
The same as SaveToCache, except the expire date/time is passed as a CkDateTime object.
Returns TRUE for success, FALSE for failure.
topSaveToCacheNoExpire
Inserts or replaces an item in the cache. The cached item will have no expiration. 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 TRUE for success, FALSE for failure.
SaveToCacheStr
The same as SaveToCache, except the expire date/time is passed in RFC822 string format.
Returns TRUE for success, FALSE for failure.
topUpdateExpirationDt
The same as UpdateExpiration, except the expireDateTime is passed as a CkDateTime.
Returns TRUE for success, FALSE for failure.
topUpdateExpirationStr
The same as UpdateExpiration, except the expireDateTime is passed in RFC822 string format.
Returns TRUE for success, FALSE for failure.
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