utility

The utility command can be used to place commonly used programs into a special cache. As an example:

utility __Download/RunQuiet.exe

This places the common RunQuiet program into the utility cache to avoid downloading it multiple times.

The 6.0 clients maintain two disk caches; one for utility programs and another for action payloads. Files arriving in the action payload cache will not push files out of the utilities cache and vice versa.

The 6.0 clients use the sha1 or sha256 value of an action download to locate any matching utility (such as RunQuiet) that already exists on the client.

An action-specific folder is created to contain downloads as they are pre-fetched. Existing files that match the sha1 or sha256 values don't need to be downloaded again. Any other files will be pre-fetched from the parent relay. When all the downloads are available on the client, the files will be moved from the action-specific folder (this is a change from pre 6.0 client behavior) to the __Download folder of the action site and the action will be started.

When the action completes, any files left in the __Download folder that were pre-fetched with sha1 or sha256 will be candidates for utility caching. These files will have their sha1 or sha256 values re-computed and any files with matching sha1 or sha256 values can be moved into the utility cache.

A least-recently used scheme is used to keep the cache within its size limits. For short intervals only, the cache limit may be exceeded by single files.

Syntax

utility <pathname>

Example

prefetch patch.exe sha1:92c643875dda80022b3ce3f1ad580f62704b754f
__size:813160 http://www.download.windowsupdate.com/msdownload/update/v3-
__19990518/cabpool/q307869_f323efa52f460ea1e5f4201b011c071ea5b95110.exe 
utility __Download\patch.exe 
wait __Download\patch.exe 

This example prefetches a file, saves the file to the utility cache as patch.exe and waits for its completion to continue the action.

Version 6.0 and above -- Windows Only