[asterisk-scf-dev] Changes regarding state replicator keys

[Kevin P. Fleming]

On 12/14/2010 05:53 AM, Brent Eagles wrote:
> On Mon, Dec 13, 2010 at 01:39:06PM -0600, David M. Lee wrote:
>> On Dec 13, 2010, at 12:01 PM, Mark Michelson wrote:
>>
>>> 1) Instead of using a templated type for the key, use std::string.
>>> std::string has a .c_str() method that will give a const char * to the
>>> actual string content, and std::string has a size() method for reporting
>>> the size of the string.
>>
>> +1.  If you have some class you want to use for your identifier, you
>> just need to make sure that you can convert that class to std::string.
>>
>> Conversions from std::string to the id class are probably an
>> anti-pattern, since you're then using the identity column for more
>> than just identity.  You can easily put such information in the value
>> that's being stored, so that's not too limiting.
>
>
> I had to think about this one a little bit because I didn't quite get
> David's point. It did finally dawn on me that we were talking
> specifically about replication, not general database type stuff.  *If*
> we were building some mechanism for storing arbitrary data, then it
> would make sense to have some versatility with respect to the key type.
> However, this is specific to replication so it is not that big of a deal
> to restrict the key type to strings.
>
> On a related note, does memcached restrict key length?
>
> <snip>
>
> I also agree with David on the other two possibilities, so I'm just
> going to snip those out.

My preference would be to not restrict the user of the template to only 
being able to use std::string for keys. I can easily envision 
applications where the key will be a structure of multiple fields, and 
forcing the user of the template to have to convert to/from std::string 
seems unnecessary.

My vote would be for the template to just continue to accept a template 
type parameter (K), and require that that type have a size() member 
function, an 'operator char[]' conversion function, and a constructor 
that accepts 'char[], int'.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
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