Investigate using Jason instead of Poison

[josevalim]

This will also require changing phoenix_ecto / ecto.

[wilbertom]

What can of investigation needs to be done for this? Is it:

• How much effort it would be
• Seeing if there is a performance boost
• Something else?

[chrismccord]

It won't be a large effort. The only thing to evaluate is the readiness of Jason stability and prod ready wise.

[michalmuskala]

The biggest difference of Jason vs Poison is that Jason does not allow encoding arbitrary structs - it always requires either implementing or deriving the protocol. This would mean the change wouldn't be completely seamless - fortunately, deriving the protocol is just one line Protocol.derive(Jason.Encoder, MyStruct).

[michalmuskala]

Just an FYI, I've released version 1.0.

[chrismccord]

@josevalim this is taken care of in #2734 , and phoenix_ecto no longer depends or implements any Poison protocol so we are good there. What needs done on Ecto's side to make this complete?

[mpranjic]

Can someone explain what are the benefits of using Jason instead of Poison?

[michalmuskala]

The primary reason is performance. Jason is about twice as fast and uses half the memory while being almost 100% functionally compatible with Poison (it covers all the features used directly in Phoenix).

[javierg]

Will this be released to 1.3?

[beardedeagle]

@javierg if you look at Jason's readme, instructions are provided for use with phoenix 1.3:
https://github.com/michalmuskala/jason/blob/master/README.md