perf flamegraph: flamegraph.py script improvements

# Written by Andreas Gerstmayr <agerstmayr@redhat.com>

# Flame Graphs invented by Brendan Gregg <bgregg@netflix.com>

# Works in tandem with d3-flame-graph by Martin Spier <mspier@netflix.com>

#

# pylint: disable=missing-module-docstring

# pylint: disable=missing-class-docstring

# pylint: disable=missing-function-docstring

from __future__ import print_function

import sys

import io

import argparse

import json

import subprocess

# pylint: disable=too-few-public-methods

class Node:

    def __init__(self, name, libtype=""):

    def __init__(self, name, libtype):

        self.name = name

        # "root" | "kernel" | ""

        # "" indicates user space

        self.libtype = libtype

        self.value = 0

        self.children = []

    def toJSON(self):

    def to_json(self):

        return {

            "n": self.name,

            "l": self.libtype,

class FlameGraphCLI:

    def __init__(self, args):

        self.args = args

        self.stack = Node("root")

        self.stack = Node("all", "root")

        if self.args.format == "html" and \

                not os.path.isfile(self.args.template):

                  file=sys.stderr)

            sys.exit(1)

    def find_or_create_node(self, node, name, dso):

        libtype = "kernel" if dso == "[kernel.kallsyms]" else ""

        if name is None:

            name = "[unknown]"

    @staticmethod

    def get_libtype_from_dso(dso):

        """

        when kernel-debuginfo is installed,

        dso points to /usr/lib/debug/lib/modules/*/vmlinux

        """

        if dso and (dso == "[kernel.kallsyms]" or dso.endswith("/vmlinux")):

            return "kernel"

        return ""

    @staticmethod

    def find_or_create_node(node, name, libtype):

        for child in node.children:

            if child.name == name and child.libtype == libtype:

            if child.name == name:

                return child

        child = Node(name, libtype)

        return child

    def process_event(self, event):

        node = self.find_or_create_node(self.stack, event["comm"], None)

        pid = event.get("sample", {}).get("pid", 0)

        # event["dso"] sometimes contains /usr/lib/debug/lib/modules/*/vmlinux

        # for user-space processes; let's use pid for kernel or user-space distinction

        if pid == 0:

            comm = event["comm"]

            libtype = "kernel"

        else:

            comm = "{} ({})".format(event["comm"], pid)

            libtype = ""

        node = self.find_or_create_node(self.stack, comm, libtype)

        if "callchain" in event:

            for entry in reversed(event['callchain']):

                node = self.find_or_create_node(

                    node, entry.get("sym", {}).get("name"), event.get("dso"))

            for entry in reversed(event["callchain"]):

                name = entry.get("sym", {}).get("name", "[unknown]")

                libtype = self.get_libtype_from_dso(entry.get("dso"))

                node = self.find_or_create_node(node, name, libtype)

        else:

            node = self.find_or_create_node(

                node, entry.get("symbol"), event.get("dso"))

            name = event.get("symbol", "[unknown]")

            libtype = self.get_libtype_from_dso(event.get("dso"))

            node = self.find_or_create_node(node, name, libtype)

        node.value += 1

    def get_report_header(self):

        if self.args.input == "-":

            # when this script is invoked with "perf script flamegraph",

            # no perf.data is created and we cannot read the header of it

            return ""

        try:

            output = subprocess.check_output(["perf", "report", "--header-only"])

            return output.decode("utf-8")

        except Exception as err:  # pylint: disable=broad-except

            print("Error reading report header: {}".format(err), file=sys.stderr)

            return ""

    def trace_end(self):

        json_str = json.dumps(self.stack, default=lambda x: x.toJSON())

        stacks_json = json.dumps(self.stack, default=lambda x: x.to_json())

        if self.args.format == "html":

            report_header = self.get_report_header()

            options = {

                "colorscheme": self.args.colorscheme,

                "context": report_header

            }

            options_json = json.dumps(options)

            try:

                with io.open(self.args.template, encoding="utf-8") as f:

                    output_str = f.read().replace("/** @flamegraph_json **/",

                                                  json_str)

            except IOError as e:

                print("Error reading template file: {}".format(e), file=sys.stderr)

                with io.open(self.args.template, encoding="utf-8") as template:

                    output_str = (

                        template.read()

                        .replace("/** @options_json **/", options_json)

                        .replace("/** @flamegraph_json **/", stacks_json)

                    )

            except IOError as err:

                print("Error reading template file: {}".format(err), file=sys.stderr)

                sys.exit(1)

            output_fn = self.args.output or "flamegraph.html"

        else:

            output_str = json_str

            output_str = stacks_json

            output_fn = self.args.output or "stacks.json"

        if output_fn == "-":

            try:

                with io.open(output_fn, "w", encoding="utf-8") as out:

                    out.write(output_str)

            except IOError as e:

                print("Error writing output file: {}".format(e), file=sys.stderr)

            except IOError as err:

                print("Error writing output file: {}".format(err), file=sys.stderr)

                sys.exit(1)

    parser.add_argument("--template",

                        default="/usr/share/d3-flame-graph/d3-flamegraph-base.html",

                        help="path to flame graph HTML template")

    parser.add_argument("--colorscheme",

                        default="blue-green",

                        help="flame graph color scheme",

                        choices=["blue-green", "orange"])

    parser.add_argument("-i", "--input",

                        help=argparse.SUPPRESS)

    args = parser.parse_args()

    cli = FlameGraphCLI(args)

    cli_args = parser.parse_args()

    cli = FlameGraphCLI(cli_args)

    process_event = cli.process_event

    trace_end = cli.trace_end