view mercurial/lsprofcalltree.py @ 45047:40120de810ba stable

demandimport: ignore `lzma` module for demandimport

This makes importing the module fail if the `_lzma` module is not present.

This makes e.g. tarfile correctly recognize if LZMA support is not present. It
changes the exception

    File "/usr/lib/python3.6/tarfile.py", line 1694, in xzopen
      fileobj = lzma.LZMAFile(fileobj or name, mode, preset=preset)
  AttributeError: module 'lzma' has no attribute 'LZMAFile'

to the more correct exception

    File "/usr/lib/python3.6/tarfile.py", line 1692, in xzopen
      raise CompressionError("lzma module is not available")
  tarfile.CompressionError: lzma module is not available

Also, it prevents that the error "abort: No module named '_lzma'!" is shown when
a development warning is to be shown. The reason why that happened is that for
showing the warning, we get information about the stack frames from the inspect
module, which accesses the `__file__` attribute of all modules in `sys.modules`
to build some cache, causing all modules (including `lzma`) to be imported.

"""
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))