Summary: A much smaller tree than the previous one. It only has 100 or so nodes
Reviewed By: NickGerleman
Differential Revision: D53632451
fbshipit-source-id: 1268499fa768f3b6673ff8bcedac23cf6d9395ac
Summary:
In addition to all the state that gets set on the node that is easy to serialize - like floats, enums, bools, etc - we also need to serialize measure functions. This is because these functions take a nontrivial amount of time up during layout and we should capture that. Also, they are important to the ability to truly replay layout as it was captured as the results of the measure functions determine many of the steps the layout algorithm takes.
Capturing this is rather tricky however, but I think I found a solution that is relatively simple and non-error prone. Essentially, since we are capturing the entire tree and virtually every input that goes into the flexbox algorithm, we *should* be able to replay layout exactly as it was captured. This means that the order in which measure functions are called *should* be the same. If this is the case, then all we need to do to capture the measure functions is store their input, output, and duration in a big array. During deserialization we just keep track of an index and use that to determine which measure function we should call. That is the premise behind what happens in this diff. In theory the algorithm could change and the capture would be wrong but it is easy enough to recapture again. Additionally we need to dirty the tree so that we get rid of caching which might omit some measure func calls
In order to capture you need to insert a method exposed by CaptureTree.h into the client measure func, which is kind of annoying but not that bad. In future diffs I will put a macro in place to make this even easier.
I also add our first capture! Which is of a large react native desktop app
Reviewed By: NickGerleman
Differential Revision: D53581121
fbshipit-source-id: 876a230208d67f0ecf76844a4f1b80048353aae2
