##// END OF EJS Templates
revlog: add a small cache of unfiltered chunk...
revlog: add a small cache of unfiltered chunk This can provides a massive boost to the reading of multiple revision and the computation of a valid delta chain. This greatly help operation like `hg log --patch`, delta computation (helping pull/unbundle), linkrev adjustment (helping copy tracing). A first round of benchmark for `hg log --patch --limit 1000` shows improvement in the 10-20% range on "small" repository like pypy or mercurial and large improvements (about 33%) for more complex ones like netbeans and mozilla's. These speeds up are consistent with the improvement to `hg pull` (from a server sending poor deltas) I saw benchmarking this last year. Further benchmark will be run during the freeze. I added some configuration in the experimental space to be able to further test the effect of various tuning for now. This feature should fit well in the "usage/resource profile" configuration that we should land next cycle. When it does not provides a benefit the overhead of the cache seem to be around 2%, a small price for the big improvement. In addition I believe we could shave most of this overhead with a more efficent lru implementation.

File last commit:

r49730:6000f5b2 default
r52001:0250e450 default
Show More
bdiff-torture.py
107 lines | 2.1 KiB | text/x-python | PythonLexer
# Randomized torture test generation for bdiff
import random
import sys
from mercurial import (
mdiff,
pycompat,
)
def reducetest(a, b):
tries = 0
reductions = 0
print("reducing...")
while tries < 1000:
a2 = (
"\n".join(l for l in a.splitlines() if random.randint(0, 100) > 0)
+ "\n"
)
b2 = (
"\n".join(l for l in b.splitlines() if random.randint(0, 100) > 0)
+ "\n"
)
if a2 == a and b2 == b:
continue
if a2 == b2:
continue
tries += 1
try:
test1(a, b)
except Exception:
reductions += 1
tries = 0
a = a2
b = b2
print("reduced:", reductions, len(a) + len(b), repr(a), repr(b))
try:
test1(a, b)
except Exception as inst:
print("failed:", inst)
sys.exit(0)
def test1(a, b):
d = mdiff.textdiff(a, b)
if not d:
raise ValueError("empty")
c = mdiff.patches(a, [d])
if c != b:
raise ValueError("bad")
def testwrap(a, b):
try:
test1(a, b)
return
except Exception as inst:
print("exception:", inst)
reducetest(a, b)
def test(a, b):
testwrap(a, b)
testwrap(b, a)
def rndtest(size, noise):
a = []
src = " aaaaaaaabbbbccd"
for x in pycompat.xrange(size):
a.append(src[random.randint(0, len(src) - 1)])
while True:
b = [c for c in a if random.randint(0, 99) > noise]
b2 = []
for c in b:
b2.append(c)
while random.randint(0, 99) < noise:
b2.append(src[random.randint(0, len(src) - 1)])
if b2 != a:
break
a = "\n".join(a) + "\n"
b = "\n".join(b2) + "\n"
test(a, b)
maxvol = 10000
startsize = 2
while True:
size = startsize
count = 0
while size < maxvol:
print(size)
volume = 0
while volume < maxvol:
rndtest(size, 2)
volume += size
count += 2
size *= 2
maxvol *= 4
startsize *= 4