tree 765c5c8add20abca7d7310846233f4bd8d9f10c6
parent 8e70ce20c5936c8beb5a744c3f63addfde0783b3
author Allen Li <ayatane@google.com> 1481075357 -0800
committer chrome-bot <chrome-bot@chromium.org> 1481336731 -0800

Add support for recursive requirements

Add a script to expand recursive requirements.  This allows recursive
requirements to be tracked and updated; otherwise, we wouldnt know
about new requirements in included subfiles.

We do this because:

1. We cannot reliably check whether we need to update if we dont
   expand included dependencies.
2. Not checking if we need to update and always updating adds 2+
   seconds to each call to create_venv, which is also run under an
   exclusive lock, significantly increasing the cost of virtualenv
   commands.

The current implementation is a balance between simplicity,
performance, and maintainability.  If more additions are added, we
should consider rewriting in Python.

BUG=chromium:645611
TEST=Run locally with recursive requirements.txt

Change-Id: Iffffa7348fade4113439fd4e372b3009090e2a47
Reviewed-on: https://chromium-review.googlesource.com/417248
Commit-Ready: Allen Li <ayatane@chromium.org>
Tested-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>