tree 7d8ddec98581f0715e3b68474f71d46ca97c3d5d
parent 5bedd861b12ec5276c0877b760e82f0469c7bf79
author Alan Donovan <adonovan@google.com> 1673640739 -0500
committer Alan Donovan <adonovan@google.com> 1674053684 +0000

internal/gcimporter: discard position info for unneeded lines

This change implements an optimization in the size of the
shallow export data: instead of saving the entire line
start offset table of each file, it saves a sparse representation
of each file capable of restoring accurate position information
for the entirety of each line that contains an encoded token.Pos,
but no others.

This reduces the total size of export data for the standard library
to 665KB, down 31% from 957KB, and only 18% more than the original
baseline of 564KB.

The shallow_test asserts (for a couple of specific objects) that
the end positions may be derived from the start positions either
before or after converting token.Pos to token.Position.

Change-Id: I5c2a1648398d0bee979dc36ba6224072ea183bec
Reviewed-on: https://go-review.googlesource.com/c/tools/+/462096
gopls-CI: kokoro <noreply+kokoro@google.com>
Run-TryBot: Alan Donovan <adonovan@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>