stream-clone: disable gc for the initial section for the v3 format The number of small container created turn Python in a gc-frenzy that seriously impact performance. This significantly boost performance. The following number comes from a large private repository using perf::stream-locked-section: base-line: 35.04 seconds prev-change: 24.51 seconds (-30%) prev-change: 20.88 seconds (-40%) this-change: 14.22 seconds (-60% from baseline; -31% from prev)

import os
import time


class mocktime:
    def __init__(self, increment):
        self.time = 0
        self.increment = [float(s) for s in increment.split()]
        self.pos = 0

    def __call__(self):
        self.time += self.increment[self.pos % len(self.increment)]
        self.pos += 1
        return self.time


def uisetup(ui):
    time.time = mocktime(os.environ.get('MOCKTIME', '0.1'))