proposal: Support parameter passing through http headers

[Hamdi Roumani]

Add support to allow headers specified on a request to be passed down to the storlet engine.

There are methods for doing this today but they are not as elegant:

1)

I think you were inferring this from the first sentance but you actually can pass input data to a storlet by utilizing query strings. You can see the basic test storlet does just this:
params = 'op={0}&param2=val2'.format(op) // e.g. 'op' may be 'print' => op=print&param2=val2

c.get_object(url, token, 'myobjects', 'test_object', None, None, params, resp_dict, headers)

These are supplied to the storlet through a map object in the invoke function:
public void invoke(ArrayList<StorletInputStream> inputStreams, ..., Map<String, String> params, ...

2)

Another indirect way of passing information to the storlet is through object metadata e.g. if you add:

swift post --meta "HamdiValue:Test" myobjects junk.txt

You can access this directly from the storlet.

[Takashi Kajinami (kajinamit)]

I think this feature is already implemented in master, as X-Storlet-Parameter-* header.