UseSystemCache Property

Whether the operating system's cache is used.

Syntax

 cbdrive.getUseSystemCache([callback])
 cbdrive.setUseSystemCache( useSystemCache, [callback])

Default Value

TRUE

Callback

The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).

The callback for the getUseSystemCache([callback]) method is defined as:

function(err, data){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'data' is the value returned by the method.

The callback for the setUseSystemCache([callback]) method is defined as:

function(err){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'err' has 2 properties which hold detailed information:

err.code
err.message

Remarks

This property specifies whether the operating system's cache should be used. Use of the OS cache affects the speed of various vault operations; however, note that the exact effects depend on the type of operation as well as the data sizes involved.

For the CBVault class, disabling this property will cause a vault's storage file (specified by the VaultFile property) to be opened with FILE_FLAG_NO_BUFFERING (on Windows) or F_NOCACHE (on Linux/macOS). This also applies for the CBDrive class on Linux and macOS.

For the CBDrive class on Windows, a vault's storage file is always opened with FILE_FLAG_NO_BUFFERING regardless of how this property is set; disabling this property prevents the system cache from being used to cache files on the virtual drive. This may be necessary in certain situations in order to prevent BSODs. Please refer to Microsoft's File Caching article for more information about the system file cache.

Note: This property cannot be changed when Active is true, and cannot be changed within events.

Data Type

Boolean