[cups.development] Re: [RFE] STR #1461: minimize copying (tighten temp-space bounds) in filter pipeline where possible

[Michael Sweet]

[STR Closed w/o Resolution]

FWIW, the SPS is going away in 1.2; most of the content is part of the new
1.2 design description page (still a work in progress), but the purpose is
more for server planning than for strict documentation. As for the size of
temporary files, the output side can be larger or smaller depending on the
device - there is no hard and fast rule.

The design documentation has never been meant to be detailed, as the code
and related standards specifications are a far better and more accurate
source of information than a separate document.

As for the temporary file usage, we only use them when we have to.

IPP and HTTP/1.1 require support for chunking, however a) HP's
implementation of IPP violates the spec and does not support chunking, and
b) we need to save the print data for retries (network errors,
authentication, etc.) Therefore, we can't rely on streaming support in the
IPP backend and will always need to create that temporary file.

Backends, as invoked by CUPS, will always either have the filenames on the
command-line or get the print data on stdin via a pipe. Thus, the current
checks are 100% correct. Please read the SDD, IDD, SPM, and man pages to
fully understand how CUPS works.

Link: http://www.cups.org/str.php?L1461
Version:  -feature
Fix Version: None