commit 609f9826e55a285482670d747c23c8ecc151b6e8
author Maxime Guerreiro <maximeg@google.com> Fri Apr 27 13:01:41 2018 +0000
committer Maxime Guerreiro <maximeg@google.com> Tue May 08 15:13:24 2018 +0000
tree feb16c07be1db3f7e2abe52ee9afa45fb8ca3915
parent 49edeea3d037f15d908db4ef432ae7a1f326dcbd

Replace all lambdas with method references, when possible

Every time a lambda taking an argument is created, an object is created.
This object is unique and makes it harder for the JIT compilation to
optimize the code.

By replacing lambdas with method references, we help the JIT better
understand our code, and reduce object creations* and garbage
collection.

Using method references also helps humans better understand the code,
and might even make compilation faster: the method, and where it lives,
is explicitely written: no need to guess it.

    repoUpgraded.stream().map(n -> n.get()).collect(...);
Where does the get method come from? Hard to tell.

    repoUpgraded.stream().map(NameKey::get).collect()
Same line of code, using a method reference. It is clear that the input
objects are NameKey-s, and we call the get method on them.

* This is technically wrong, as a pointer is created even when we use a
method reference, but it is at least smaller than the lambda
counterpart.

Change-Id: Ic85b1b593d42968f262d3afe49a2ad87a4b766b9