Re: rados_pool_list usage

[Wido den Hollander <wido@42on.com>]

On 03/27/2013 06:40 PM, Dan Mick wrote:
> It looks like it attempts to behave as documented (somewhat surprisingly
> and fragile-ly, IMO; I would have made it all-or-nothing and return
> nothing in buf if len is too small).
>
> The Python binding retries/resizes until it can return them all.
>
> What do you think is wrong, Wido?
>

Well, I think I kind of misread the description..

I didn't see the @return part of it which confused me about how it works.

There is a typo though: "List objects in a pool"

That should be: "List all pools"

Wido

> On 03/27/2013 08:59 AM, Gregory Farnum wrote:
>>
>>
>> On Wednesday, March 27, 2013 at 1:59 AM, Wido den Hollander wrote:
>>
>>> Hi,
>>>
>>> While working with rados_pool_list I stumbled upon what I think is a
>>> documentation issue.
>>>
>>> librados.h tells me this:
>>>
>>> /**
>>> * List objects in a pool
>>> *
>>> * Gets a list of pool names as NULL-terminated strings. The pool
>>> * names will be placed in the supplied buffer one after another.
>>> * After the last pool name, there will be two 0 bytes in a row.
>>> *
>>> * If len is too short to fit all the pool name entries we need, we
>>> will fill
>>> * as much as we can.
>>> *
>>> * @param cluster cluster handle
>>> * @param buf output buffer
>>> * @param len output buffer length
>>> * @returns length of the buffer we would need to list all pools
>>> */
>>> int rados_pool_list(rados_t cluster, char *buf, size_t len);
>>>
>>> "If len is too short to fit all the pool name entries we need, we will
>>> fill as much as we can."
>>>
>>>  From what I could remember it would return the length required if "len"
>>> isn't long enough. Looking at the Python and PHP bindings (which I
>>> wrote) it seems that is correct.
>>>
>>> It also says: "@returns length of the buffer we would need to list all
>>> pools"
>>>
>>> Docs issue I guess?
>> It certainly returns the amount of space needed; does it not also fill
>> in the given buffer with however many pools it could? (It might not,
>> but those sentences aren't contradictory in my mind.)
>> -Greg
>> Software Engineer #42 @ http://inktank.com | http://ceph.com
>>
>>
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-- 
Wido den Hollander
42on B.V.

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