CkCache C++ Reference Documentation

CkCache

Current Version: 10.0.0

Requires Chilkat Bundle License

Object Creation

// Local variable on the stack
CkCache obj;

// Dynamically allocate/delete
CkCache *pObj = new CkCache();
// ...
delete pObj;

Properties

DebugLogFilePath

void get_DebugLogFilePath(CkString &str);
const char *debugLogFilePath(void);
void put_DebugLogFilePath(const char *ansiOrUtf8Str);

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

void get_LastErrorHtml(CkString &str);
const char *lastErrorHtml(void);

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

void get_LastErrorText(CkString &str);
const char *lastErrorText(void);

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

void get_LastErrorXml(CkString &str);
const char *lastErrorXml(void);

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

void get_LastEtagFetched(CkString &str);
const char *lastEtagFetched(void);

The ETag of the last item fetched from cache.

LastExpirationFetchedStr

void get_LastExpirationFetchedStr(CkString &str);
const char *lastExpirationFetchedStr(void);

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

LastHitExpired

bool get_LastHitExpired(void);

true if the LastExpirationFetched is before the current date/time. Otherwise false.

LastKeyFetched

void get_LastKeyFetched(CkString &str);
const char *lastKeyFetched(void);

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

bool get_LastMethodSuccess(void);
void put_LastMethodSuccess(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.

Level

int get_Level(void);
void put_Level(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).

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

int get_NumRoots(void);

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

Utf8

bool get_Utf8(void);
void put_Utf8(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.

VerboseLogging

bool get_VerboseLogging(void);
void put_VerboseLogging(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.

Version

void get_Version(CkString &str);
const char *version(void);

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

void AddRoot(const char *path);

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

int DeleteAll(void);

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

int DeleteAllExpired(void);

Deletes all expired items from the cache.

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

DeleteFromCache

bool DeleteFromCache(const char *key);

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.

DeleteOlderDt

int DeleteOlderDt(CkDateTime &dateTime);

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

DeleteOlderStr

int DeleteOlderStr(const char *dateTimeStr);

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

FetchBd

bool FetchBd(const char *key, CkBinData &bd);

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 true for success, false for failure.

FetchFromCache

bool FetchFromCache(const char *key, CkByteData &outBytes);

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.

More Information and Examples

Facebook Download all Photos to Local Files

FetchSb

bool FetchSb(const char *key, CkStringBuilder &sb);

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 true for success, false for failure.

FetchText

bool FetchText(const char *key, CkString &outStr);
const char *fetchText(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.

More Information and Examples

Large Persistent Hash Table Stored on Filesystem

GetEtag

bool GetEtag(const char *key, CkString &outStr);
const char *getEtag(const char *key);

Returns the eTag for an item in the cache.

Returns true for success, false for failure.

GetExpirationDt

CkDateTime *GetExpirationDt(const char *key);

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

Note: The application is responsible for deleting (via the C++ delete operator) the object returned by this method.

Returns NULL on failure

GetExpirationStr

bool GetExpirationStr(const char *url, CkString &outStr);
const char *getExpirationStr(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.

GetFilename

bool GetFilename(const char *key, CkString &outStr);
const char *getFilename(const char *key);

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

Returns true for success, false for failure.

GetRoot

bool GetRoot(int index, CkString &outStr);
const char *getRoot(int index);

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

Returns true for success, false for failure.

IsCached

bool IsCached(const char *key);

Returns true if the item is found in the cache, otherwise returns false.

SaveTextDt

bool SaveTextDt(const char *key, CkDateTime &expireDateTime, const char *eTag, const char *itemTextData);

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

Returns true for success, false for failure.

SaveTextNoExpire

bool SaveTextNoExpire(const char *key, const char *eTag, const char *itemTextData);

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.

More Information and Examples

Large Persistent Hash Table Stored on Filesystem

SaveTextStr

bool SaveTextStr(const char *key, const char *expireDateTime, const char *eTag, const char *itemTextData);

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

Returns true for success, false for failure.

SaveToCacheDt

bool SaveToCacheDt(const char *key, CkDateTime &expireDateTime, const char *eTag, CkByteData &itemData);

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

Returns true for success, false for failure.

SaveToCacheNoExpire

bool SaveToCacheNoExpire(const char *key, const char *eTag, CkByteData &itemData);

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.

More Information and Examples

Facebook Download all Photos to Local Files

SaveToCacheStr

bool SaveToCacheStr(const char *key, const char *expireDateTime, const char *eTag, CkByteData &itemData);

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

Returns true for success, false for failure.

UpdateExpirationDt

bool UpdateExpirationDt(const char *key, CkDateTime &expireDateTime);

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

Returns true for success, false for failure.

UpdateExpirationStr

bool UpdateExpirationStr(const char *key, const char *expireDateTime);

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

Returns true for success, false for failure.