Add ttl and timestamp support to insert/update operations

[nicodeslandes]

This PR updates the Mapper and CqlBatch classes to provide the ability to specify a TTL or a TIMESTAMP option when performing an insert operation.

This is done using the new CqlQueryOptions class when calling IMapper.Insert, like this:

mapper.Insert(newUser, new CqlInsertOptions
                       {
                           Ttl = TimeSpan.FromSeconds(42),
                           Timestamp = DateTimeOffset.Parse("2014-2-1")
                       });

The more "Java-like" syntax offered by CqlQueryOptions is also available:

mapper.Insert(newUser,
    CqlInsertOptions.New().
        SetTtl(TimeSpan.FromSeconds(42)).
        SetTimestamp(DateTimeOffset.Parse("2014-2-1")));

The InsertIfExists variant can also take CqlQueryOptions.

The same can be implemented for Update operations, but I thought 'd get some feedback on the initial implementation for Inserts first before moving on to that.

Note

Another way to add TTL and TIMESTAMP options would have been to either change or subclass CqlQueryOptions. But I thought it might be better to add a new class altogether for 2 reasons:

• The Insert/InsertIfExists methods already take a CqlQueryOptions and I didn't want to change their signature, to avoid breaking backward compatibility issues. I could have subclassed CqlQueryOptions without changing the signature of Insert, but then the new options would not have been easily discoverable
• The current CqlQueryOptions define options to apply at the IStatement level, and don't control how CQL query strings are generated, so it has a slightly different scope from CqlInsertOptions.

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[jorgebay]

Looks good, I'll make a full review shortly.

[jorgebay]

I don't think its a good idea to add more cql generation to the Mapper, I think the purpose of the Mapper is to not get in the way of the queries. It generates and completes the default queries, but if the user wants cql control (like in this case field TTL), the user should write the query using the other method overloads.

Initially I thought it was related to protocol-level timestamp, but not query based timestamp and TTL, sorry for that.

@LukeTillman: What do you think?

[LukeTillman]

Yeah, I agree about keeping the CQL generation to a minimum. Although I do think we should support protocol level timestamp in v3:

https://github.com/apache/cassandra/blob/trunk/doc/native_protocol_v3.spec#L322

Since TTLs are in seconds, those are pretty easy to just provide as query parameters using the BCL (i.e. TimeSpan.FromXXX().TotalSeconds). Query-based timestamps are a little trickier since they're microseconds since epoch and I have a utility class I've been using for to generate values for those:

https://github.com/LukeTillman/killrvideo-csharp/blob/master/src/KillrVideo.Utils/MicrosecondsSinceEpoch.cs

[LukeTillman]

I wouldn't be opposed to including a query builder that builds Cql instances though (that could potentially include TTL and Timestamp methods). Doesn't the Java driver have a builder API like that?

[jorgebay]

The java driver has a query builder API, but we also have Linq that generates the cql queries from a typed expression. I think, from a product standpoint, it makes sense to recommend Linq when the user wants cql generation (and mapping) and recommend the Mapper when the user wants to write their own queries and get the results mapped.

[collinsauve]

@jorgebay I believe this can be closed? Ttl is now supported as an overload to insert (but not update), and timestamp is supported on both insert and update via CqlQueryOptions.

[jorgebay]

Thanks for the reminder!