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waf/waflib/extras/mem_reducer.py

112 lines
2.4 KiB
Python

#! /usr/bin/env python
# encoding: UTF-8
"""
This tool can help to reduce the memory usage in very large builds featuring many tasks with after/before attributes.
It may also improve the overall build time by decreasing the amount of iterations over tasks.
Usage:
def options(opt):
opt.load('mem_reducer')
"""
import itertools
from waflib import Utils, Task, Runner
class SetOfTasks(object):
"""Wraps a set and a task which has a list of other sets.
The interface is meant to mimic the interface of set. Add missing functions as needed.
"""
def __init__(self, owner):
self._set = owner.run_after
self._owner = owner
def __iter__(self):
for g in self._owner.run_after_groups:
#print len(g)
for task in g:
yield task
for task in self._set:
yield task
def add(self, obj):
self._set.add(obj)
def update(self, obj):
self._set.update(obj)
def set_precedence_constraints(tasks):
cstr_groups = Utils.defaultdict(list)
for x in tasks:
x.run_after = SetOfTasks(x)
x.run_after_groups = []
x.waiting_sets = []
h = x.hash_constraints()
cstr_groups[h].append(x)
# create sets which can be reused for all tasks
for k in cstr_groups.keys():
cstr_groups[k] = set(cstr_groups[k])
# this list should be short
for key1, key2 in itertools.combinations(cstr_groups.keys(), 2):
group1 = cstr_groups[key1]
group2 = cstr_groups[key2]
# get the first entry of the set
t1 = next(iter(group1))
t2 = next(iter(group2))
# add the constraints based on the comparisons
if Task.is_before(t1, t2):
for x in group2:
x.run_after_groups.append(group1)
for k in group1:
k.waiting_sets.append(group1)
elif Task.is_before(t2, t1):
for x in group1:
x.run_after_groups.append(group2)
for k in group2:
k.waiting_sets.append(group2)
Task.set_precedence_constraints = set_precedence_constraints
def get_out(self):
tsk = self.out.get()
if not self.stop:
self.add_more_tasks(tsk)
self.count -= 1
self.dirty = True
# shrinking sets
try:
ws = tsk.waiting_sets
except AttributeError:
pass
else:
for k in ws:
try:
k.remove(tsk)
except KeyError:
pass
return tsk
Runner.Parallel.get_out = get_out
def skip(self, tsk):
tsk.hasrun = Task.SKIPPED
# shrinking sets
try:
ws = tsk.waiting_sets
except AttributeError:
pass
else:
for k in ws:
try:
k.remove(tsk)
except KeyError:
pass
Runner.Parallel.skip = skip