# perf script event handlers, generated by perf script -g python
# Licensed under the terms of the GNU GPL License version 2

# The common_* event handler fields are the most useful fields common to
# all events.  They don't necessarily correspond to the 'common_*' fields
# in the format files.  Those fields not available as handler params can
# be retrieved using Python functions of the form common_*(context).
# See the perf-trace-python Documentation for the list of available functions.

import os
import sys
import json
from collections import defaultdict

sys.path.append(os.environ["PERF_EXEC_PATH"] + "/scripts/python/Perf-Trace-Util/lib/Perf/Trace")

from perf_trace_context import *

class Function:
    def __init__(self, dso, name, sym):
        self.cost = 0
        self.dso = dso
        self.name = name
        self.sym = sym
        self.callees = defaultdict(lambda: 0)

class DSO:
    def __init__(self):
        self.functions = dict()

# a map of all encountered dso's and the functions therein
# this is done to prevent name clashes
dsos = defaultdict(lambda: DSO())

def addFunction(dsoName, name, sym):
    global dsos
    dso = dsos[dsoName]
    function = dso.functions.get(name, None)
    # create function if it's not yet known
    if not function:
        function = Function(dsoName, name, sym)
        dso.functions[name] = function
    return function

# write the callgrind file format to stdout
def trace_end():
    global dsos

    print("version: 1")
    print("creator: perf-callgrind 0.1")
    print("part: 1")
    # TODO: get access to command line, it's in the perf data header
    #       but not accessible to the scripting backend, is it?
    print("events: Samples")

    for name, dso in dsos.iteritems():
        print("ob=%s" % name)
        for sym, function in dso.functions.iteritems():
            print("fn=%s" % sym)
            print("0 %d" % function.cost)
            for callee, cost in function.callees.iteritems():
                print("cob=%s" % callee.dso)
                print("cfn=%s" % callee.name)
                print("calls=1 0")
                print("0 %d" % cost)
            print("")

def process_event(event):
    caller = None
    if not event["callchain"]:
        # only add the single symbol where we got the sample, without a backtrace
        dsoName = event.get("dso", "???")
        name = event.get("symbol", "???")
        caller = addFunction(dsoName, name, None)
    else:
        # add a function for every frame in the callchain
        for item in reversed(event["callchain"]):
            dsoName = item.get("dso", "???")
            name = "???"
            if "sym" in item:
                name = item["sym"]["name"]
            function = addFunction(dsoName, name, item.get("sym", None))
            # add current frame to parent's callee list
            if caller is not None:
                caller.callees[function] += 1
            caller = function

    # increase the self cost of the last frame
    # all other frames include it now and kcachegrind will automatically
    # take care of adapting their inclusive cost
    if caller is not None:
        caller.cost += 1