view mercurial/lsprofcalltree.py @ 47123:d8ac62374943

dirstate-tree: Make `DirstateMap` borrow from a bytes buffer

… that has the contents of the `.hg/dirstate` file.
This only applies to the tree-based flavor of `DirstateMap`.

For now only the entire `&[u8]` slice is stored, so this is not useful yet.

Adding a lifetime parameter to the `DirstateMap` struct (in hg-core) makes
Python bindings non-trivial because we keep that struct in a Python object
that has a dynamic lifetime tied to Python’s reference-counting and GC.
As long as we keep the `PyBytes` that owns the borrowed bytes buffer next to
the borrowing struct, the buffer will live long enough for the borrows to stay
valid. However this relationship cannot be expressed in safe Rust code in a
way that would statisfy they borrow-checker. We use `unsafe` code to erase
that lifetime parameter, and encapsulate it in a safe abstraction similar to
the owning-ref crate: https://docs.rs/owning_ref/

Differential Revision: https://phab.mercurial-scm.org/D10557

"""
lsprofcalltree.py - lsprof output which is readable by kcachegrind

Authors:
    * David Allouche <david <at> allouche.net>
    * Jp Calderone & Itamar Shtull-Trauring
    * Johan Dahlin

This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
"""

from __future__ import absolute_import

from . import pycompat


def label(code):
    if isinstance(code, str):
        # built-in functions ('~' sorts at the end)
        return b'~' + pycompat.sysbytes(code)
    else:
        return b'%s %s:%d' % (
            pycompat.sysbytes(code.co_name),
            pycompat.sysbytes(code.co_filename),
            code.co_firstlineno,
        )


class KCacheGrind(object):
    def __init__(self, profiler):
        self.data = profiler.getstats()
        self.out_file = None

    def output(self, out_file):
        self.out_file = out_file
        out_file.write(b'events: Ticks\n')
        self._print_summary()
        for entry in self.data:
            self._entry(entry)

    def _print_summary(self):
        max_cost = 0
        for entry in self.data:
            totaltime = int(entry.totaltime * 1000)
            max_cost = max(max_cost, totaltime)
        self.out_file.write(b'summary: %d\n' % max_cost)

    def _entry(self, entry):
        out_file = self.out_file

        code = entry.code
        if isinstance(code, str):
            out_file.write(b'fi=~\n')
        else:
            out_file.write(b'fi=%s\n' % pycompat.sysbytes(code.co_filename))

        out_file.write(b'fn=%s\n' % label(code))

        inlinetime = int(entry.inlinetime * 1000)
        if isinstance(code, str):
            out_file.write(b'0 %d\n' % inlinetime)
        else:
            out_file.write(b'%d %d\n' % (code.co_firstlineno, inlinetime))

        # recursive calls are counted in entry.calls
        if entry.calls:
            calls = entry.calls
        else:
            calls = []

        if isinstance(code, str):
            lineno = 0
        else:
            lineno = code.co_firstlineno

        for subentry in calls:
            self._subentry(lineno, subentry)

        out_file.write(b'\n')

    def _subentry(self, lineno, subentry):
        out_file = self.out_file
        code = subentry.code
        out_file.write(b'cfn=%s\n' % label(code))
        if isinstance(code, str):
            out_file.write(b'cfi=~\n')
            out_file.write(b'calls=%d 0\n' % subentry.callcount)
        else:
            out_file.write(b'cfi=%s\n' % pycompat.sysbytes(code.co_filename))
            out_file.write(
                b'calls=%d %d\n' % (subentry.callcount, code.co_firstlineno)
            )

        totaltime = int(subentry.totaltime * 1000)
        out_file.write(b'%d %d\n' % (lineno, totaltime))