Decorator

@ignore_function

@ignore_function can tell VizTracer to skip on functions you specified.

# This only works when there's a globally registered tracer
@ignore_function
def function_you_want_to_ignore():
    # function body

# You can specify tracer if no global tracer is registered
@ignore_function(tracer=tracer)
def function_you_want_to_ignore():
    # function body
@trace_and_save(method=None, output_dir='./', **viztracer_kwargs)
Parameters:

  • method (function) – trick to make both @trace_and_save and @trace_and_save(**kwargs) work

  • output_dir (str) – output directory you want to put your logs in

  • viztracer_kwargs (dict) – kwargs for VizTracer

@trace_and_save can be used to trace a certain function and save the result as the program goes. This can be very helpful when you are running a very long program and just want to keep recording something periodically. You won’t drain your memory and the parsing/dumping will be done in a new process, which can minimize the performance impact to your main process.

This decorator will use fork if the start method is "fork". Otherwise it will use the same process to dump the report.

You can pass any argument you want to VizTracer by giving it to the decorator

@trace_and_save(output_dir="./mylogs", ignore_c_function=True)
def function_you_want_to_trace():
    # function body

# this works as well
@trace_and_save
def function_you_want_to_trace():
    # function body
@log_sparse(func=None, stack_depth=0, dynamic_tracer_check=False)

You can make VizTracer log only certain functions using --log_sparse mode.

Parameters:

  • func (function) – callable to decorate

  • stack_depth (int) – log the function and its descendants with a limit stack depth

  • dynamic_tracer_check (bool) – run time check of tracer

from viztracer import log_sparse

# @log_sparse will only log this function
@log_sparse
def function_you_want_to_log():
    # function body

# @log_sparse(stack_depth=5) will log this function and its descendants
# with a limit stack depth of 5
# Nested @log_sparse with stack_depth won't work
# (only the outermost function and its stack will be logged)
@log_sparse(stack_depth=5)
def function_you_want_to_log():
    # function body

# Use dynamic_tracer_check=True if you use tracer as a context manager (or with %%viztracer).
@log_sparse(dynamic_tracer_check=True)
def function_you_want_to_log():
    # function body

with VizTracer(log_sparse=True):
    function_you_want_to_log()