Transfer Url Copy

Communication with transfer agents.

Interface arguments and memory mapped data structures

TransferUrlCopy::Args holds the information needed to start the transfer.

TransferUrlCopyStat is used to return information about a running transfer.

UrlCopyStat is used only internally by the transfer-url-copy library; UrlCopyStat and related structures are used for writing and reading memory mapped files, and they contain all the above information (operation parameters and transfer statistics).

The srm-copy part of the library has an equivalent data hierarchy.

The following diagram shows the use of transfer data structures between agents and transfer-url-copy.

During the execution of the Fetch channel action, the TransferService class creates and fills the TransferUrlCopy::Args structure and passes it to the start method of TransferUrlCopy. TransferUrlCopy translates the Args into a memory-mappable UrlCopyStat.

During the execution of the CheckState action the TransferService class invokes status on TransferUrlCopy. TransferUrlCopy, in turn, reads the memory-mapped UrlCopyStat structure; extracts from UrlCopyStat the information related to the transfer progress and fills a TransferUrlCopyStat object that is returned to TransferService.

mem files structure

Maintainer: PaoloTedesco