From e3939b0c72b2c6bc5f41e9f33de3c04cf4785c05 Mon Sep 17 00:00:00 2001
From: Todd Gamblin <tgamblin@llnl.gov>
Date: Sat, 21 Dec 2019 23:45:30 -0800
Subject: [PATCH] performance: don't recompute hashes when regenerating
environments
`ViewDescriptor.regenerate()` was copying specs and stripping build
dependencies, which clears `_hash` and other cached fields on concrete
specs, which causes a bunch of YAML hashes to be recomputed.
- [x] Preserve the `_hash` and `_normal` fields on stripped specs, as
these will be unchanged.
---
lib/spack/spack/environment.py | 11 ++++++++---
lib/spack/spack/spec.py | 2 +-
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/lib/spack/spack/environment.py b/lib/spack/spack/environment.py
index 5b526bbe11..56440fbe92 100644
--- a/lib/spack/spack/environment.py
+++ b/lib/spack/spack/environment.py
@@ -511,10 +511,15 @@ def regenerate(self, all_specs, roots):
specs = all_specs if self.link == 'all' else roots
for spec in specs:
# The view does not store build deps, so if we want it to
- # recognize environment specs (which do store build deps), then
- # they need to be stripped
+ # recognize environment specs (which do store build deps),
+ # then they need to be stripped.
if spec.concrete: # Do not link unconcretized roots
- specs_for_view.append(spec.copy(deps=('link', 'run')))
+ # We preserve _hash _normal to avoid recomputing DAG
+ # hashes (DAG hashes don't consider build deps)
+ spec_copy = spec.copy(deps=('link', 'run'))
+ spec_copy._hash = spec._hash
+ spec_copy._normal = spec._normal
+ specs_for_view.append(spec_copy)
# regeneration queries the database quite a bit; this read
# transaction ensures that we don't repeatedly lock/unlock.
diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index 86ac62e0d7..c553da796d 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -2999,7 +2999,7 @@ def _dup(self, other, deps=True, cleardeps=True, caches=None):
before possibly copying the dependencies of ``other`` onto
``self``
caches (bool or None): preserve cached fields such as
- ``_normal``, ``_concrete``, and ``_cmp_key_cache``. By
+ ``_normal``, ``_hash``, and ``_cmp_key_cache``. By
default this is ``False`` if DAG structure would be
changed by the copy, ``True`` if it's an exact copy.
--
GitLab