using storage_copy_function

[cehbrecht]

Overview

This PR adds a new server option storage_copy_function. You can choose the copy_function in FileStorage when copying outputs to the destination folder: copy, move or link. Default=copy (as it was already).

Motivation: when having large output files we don't want to copy them ... preferred method is link making a hardlink using os.link. move would be an alternative using shutil.move. Fallback is always copy with shutil.copy2.

Related Issue / Discussion

Additional Information

The link was also implemented in pywps 3.x:

pywps/pywps/Wps/Execute/__init__.py

Lines 1157 to 1164 in f18c0fd

	elif not self._samefile(output.value,outFile):
	# TODO: dirty hack to avoid copy time
	try:
	LOGGER.debug("link output: from=%s, to=%s", os.path.abspath(output.value), outFile)
	os.link(os.path.abspath(output.value), outFile)
	except:
	LOGGER.warn("failed to link output")
	COPY(os.path.abspath(output.value), outFile)

Contribution Agreement

(as per https://github.com/geopython/pywps/blob/master/CONTRIBUTING.rst#contributions-and-licensing)

• I'd like to contribute [feature X|bugfix Y|docs|something else] to PyWPS. I confirm that my contributions to PyWPS will be compatible with the PyWPS license guidelines at the time of contribution.
• I have already previously agreed to the PyWPS Contributions and Licensing Guidelines

[coveralls]

Coverage remained the same at 0.0% when pulling 5560952 on cehbrecht:storage-copy-function into 0303a6e on geopython:pywps-4.4.

[cehbrecht]

ping @Zeitsperre @huard