cpython/Lib/profiling/sampling/pstats_collector.py

412 lines
16 KiB
Python

import collections
import marshal
from _colorize import ANSIColors
from .collector import Collector
class PstatsCollector(Collector):
def __init__(self, sample_interval_usec, *, skip_idle=False):
self.result = collections.defaultdict(
lambda: dict(total_rec_calls=0, direct_calls=0, cumulative_calls=0)
)
self.stats = {}
self.sample_interval_usec = sample_interval_usec
self.callers = collections.defaultdict(
lambda: collections.defaultdict(int)
)
self.skip_idle = skip_idle
def _process_frames(self, frames):
"""Process a single thread's frame stack."""
if not frames:
return
# Process each frame in the stack to track cumulative calls
for frame in frames:
location = (frame.filename, frame.lineno, frame.funcname)
self.result[location]["cumulative_calls"] += 1
# The top frame gets counted as an inline call (directly executing)
top_location = (frames[0].filename, frames[0].lineno, frames[0].funcname)
self.result[top_location]["direct_calls"] += 1
# Track caller-callee relationships for call graph
for i in range(1, len(frames)):
callee_frame = frames[i - 1]
caller_frame = frames[i]
callee = (callee_frame.filename, callee_frame.lineno, callee_frame.funcname)
caller = (caller_frame.filename, caller_frame.lineno, caller_frame.funcname)
self.callers[callee][caller] += 1
def collect(self, stack_frames):
for frames, thread_id in self._iter_all_frames(stack_frames, skip_idle=self.skip_idle):
self._process_frames(frames)
def export(self, filename):
self.create_stats()
self._dump_stats(filename)
def _dump_stats(self, file):
stats_with_marker = dict(self.stats)
stats_with_marker[("__sampled__",)] = True
with open(file, "wb") as f:
marshal.dump(stats_with_marker, f)
# Needed for compatibility with pstats.Stats
def create_stats(self):
sample_interval_sec = self.sample_interval_usec / 1_000_000
callers = {}
for fname, call_counts in self.result.items():
total = call_counts["direct_calls"] * sample_interval_sec
cumulative_calls = call_counts["cumulative_calls"]
cumulative = cumulative_calls * sample_interval_sec
callers = dict(self.callers.get(fname, {}))
self.stats[fname] = (
call_counts["direct_calls"], # cc = direct calls for sample percentage
cumulative_calls, # nc = cumulative calls for cumulative percentage
total,
cumulative,
callers,
)
def print_stats(self, sort=-1, limit=None, show_summary=True, mode=None):
"""Print formatted statistics to stdout."""
import pstats
from .constants import PROFILING_MODE_CPU
# Create stats object
stats = pstats.SampledStats(self).strip_dirs()
if not stats.stats:
print("No samples were collected.")
if mode == PROFILING_MODE_CPU:
print("This can happen in CPU mode when all threads are idle.")
return
# Get the stats data
stats_list = []
for func, (
direct_calls,
cumulative_calls,
total_time,
cumulative_time,
callers,
) in stats.stats.items():
stats_list.append(
(
func,
direct_calls,
cumulative_calls,
total_time,
cumulative_time,
callers,
)
)
# Calculate total samples for percentage calculations (using direct_calls)
total_samples = sum(
direct_calls for _, direct_calls, _, _, _, _ in stats_list
)
# Sort based on the requested field
sort_field = sort
if sort_field == -1: # stdname
stats_list.sort(key=lambda x: str(x[0]))
elif sort_field == 0: # nsamples (direct samples)
stats_list.sort(key=lambda x: x[1], reverse=True) # direct_calls
elif sort_field == 1: # tottime
stats_list.sort(key=lambda x: x[3], reverse=True) # total_time
elif sort_field == 2: # cumtime
stats_list.sort(key=lambda x: x[4], reverse=True) # cumulative_time
elif sort_field == 3: # sample%
stats_list.sort(
key=lambda x: (x[1] / total_samples * 100)
if total_samples > 0
else 0,
reverse=True, # direct_calls percentage
)
elif sort_field == 4: # cumul%
stats_list.sort(
key=lambda x: (x[2] / total_samples * 100)
if total_samples > 0
else 0,
reverse=True, # cumulative_calls percentage
)
elif sort_field == 5: # nsamples (cumulative samples)
stats_list.sort(key=lambda x: x[2], reverse=True) # cumulative_calls
# Apply limit if specified
if limit is not None:
stats_list = stats_list[:limit]
# Determine the best unit for time columns based on maximum values
max_total_time = max(
(total_time for _, _, _, total_time, _, _ in stats_list), default=0
)
max_cumulative_time = max(
(cumulative_time for _, _, _, _, cumulative_time, _ in stats_list),
default=0,
)
total_time_unit, total_time_scale = self._determine_best_unit(max_total_time)
cumulative_time_unit, cumulative_time_scale = self._determine_best_unit(
max_cumulative_time
)
# Define column widths for consistent alignment
col_widths = {
"nsamples": 15, # "nsamples" column (inline/cumulative format)
"sample_pct": 8, # "sample%" column
"tottime": max(12, len(f"tottime ({total_time_unit})")),
"cum_pct": 8, # "cumul%" column
"cumtime": max(12, len(f"cumtime ({cumulative_time_unit})")),
}
# Print header with colors and proper alignment
print(f"{ANSIColors.BOLD_BLUE}Profile Stats:{ANSIColors.RESET}")
header_nsamples = f"{ANSIColors.BOLD_BLUE}{'nsamples':>{col_widths['nsamples']}}{ANSIColors.RESET}"
header_sample_pct = f"{ANSIColors.BOLD_BLUE}{'sample%':>{col_widths['sample_pct']}}{ANSIColors.RESET}"
header_tottime = f"{ANSIColors.BOLD_BLUE}{f'tottime ({total_time_unit})':>{col_widths['tottime']}}{ANSIColors.RESET}"
header_cum_pct = f"{ANSIColors.BOLD_BLUE}{'cumul%':>{col_widths['cum_pct']}}{ANSIColors.RESET}"
header_cumtime = f"{ANSIColors.BOLD_BLUE}{f'cumtime ({cumulative_time_unit})':>{col_widths['cumtime']}}{ANSIColors.RESET}"
header_filename = (
f"{ANSIColors.BOLD_BLUE}filename:lineno(function){ANSIColors.RESET}"
)
print(
f"{header_nsamples} {header_sample_pct} {header_tottime} {header_cum_pct} {header_cumtime} {header_filename}"
)
# Print each line with proper alignment
for (
func,
direct_calls,
cumulative_calls,
total_time,
cumulative_time,
callers,
) in stats_list:
# Calculate percentages
sample_pct = (
(direct_calls / total_samples * 100) if total_samples > 0 else 0
)
cum_pct = (
(cumulative_calls / total_samples * 100)
if total_samples > 0
else 0
)
# Format values with proper alignment - always use A/B format
nsamples_str = f"{direct_calls}/{cumulative_calls}"
nsamples_str = f"{nsamples_str:>{col_widths['nsamples']}}"
sample_pct_str = f"{sample_pct:{col_widths['sample_pct']}.1f}"
tottime = f"{total_time * total_time_scale:{col_widths['tottime']}.3f}"
cum_pct_str = f"{cum_pct:{col_widths['cum_pct']}.1f}"
cumtime = f"{cumulative_time * cumulative_time_scale:{col_widths['cumtime']}.3f}"
# Format the function name with colors
func_name = (
f"{ANSIColors.GREEN}{func[0]}{ANSIColors.RESET}:"
f"{ANSIColors.YELLOW}{func[1]}{ANSIColors.RESET}("
f"{ANSIColors.CYAN}{func[2]}{ANSIColors.RESET})"
)
# Print the formatted line with consistent spacing
print(
f"{nsamples_str} {sample_pct_str} {tottime} {cum_pct_str} {cumtime} {func_name}"
)
# Print legend
print(f"\n{ANSIColors.BOLD_BLUE}Legend:{ANSIColors.RESET}")
print(
f" {ANSIColors.YELLOW}nsamples{ANSIColors.RESET}: Direct/Cumulative samples (direct executing / on call stack)"
)
print(
f" {ANSIColors.YELLOW}sample%{ANSIColors.RESET}: Percentage of total samples this function was directly executing"
)
print(
f" {ANSIColors.YELLOW}tottime{ANSIColors.RESET}: Estimated total time spent directly in this function"
)
print(
f" {ANSIColors.YELLOW}cumul%{ANSIColors.RESET}: Percentage of total samples when this function was on the call stack"
)
print(
f" {ANSIColors.YELLOW}cumtime{ANSIColors.RESET}: Estimated cumulative time (including time in called functions)"
)
print(
f" {ANSIColors.YELLOW}filename:lineno(function){ANSIColors.RESET}: Function location and name"
)
# Print summary of interesting functions if enabled
if show_summary and stats_list:
self._print_summary(stats_list, total_samples)
@staticmethod
def _determine_best_unit(max_value):
"""Determine the best unit (s, ms, μs) and scale factor for a maximum value."""
if max_value >= 1.0:
return "s", 1.0
elif max_value >= 0.001:
return "ms", 1000.0
else:
return "μs", 1000000.0
def _print_summary(self, stats_list, total_samples):
"""Print summary of interesting functions."""
print(
f"\n{ANSIColors.BOLD_BLUE}Summary of Interesting Functions:{ANSIColors.RESET}"
)
# Aggregate stats by fully qualified function name (ignoring line numbers)
func_aggregated = {}
for (
func,
direct_calls,
cumulative_calls,
total_time,
cumulative_time,
callers,
) in stats_list:
# Use filename:function_name as the key to get fully qualified name
qualified_name = f"{func[0]}:{func[2]}"
if qualified_name not in func_aggregated:
func_aggregated[qualified_name] = [
0,
0,
0,
0,
] # direct_calls, cumulative_calls, total_time, cumulative_time
func_aggregated[qualified_name][0] += direct_calls
func_aggregated[qualified_name][1] += cumulative_calls
func_aggregated[qualified_name][2] += total_time
func_aggregated[qualified_name][3] += cumulative_time
# Convert aggregated data back to list format for processing
aggregated_stats = []
for qualified_name, (
prim_calls,
total_calls,
total_time,
cumulative_time,
) in func_aggregated.items():
# Parse the qualified name back to filename and function name
if ":" in qualified_name:
filename, func_name = qualified_name.rsplit(":", 1)
else:
filename, func_name = "", qualified_name
# Create a dummy func tuple with filename and function name for display
dummy_func = (filename, "", func_name)
aggregated_stats.append(
(
dummy_func,
prim_calls,
total_calls,
total_time,
cumulative_time,
{},
)
)
# Determine best units for summary metrics
max_total_time = max(
(total_time for _, _, _, total_time, _, _ in aggregated_stats),
default=0,
)
max_cumulative_time = max(
(
cumulative_time
for _, _, _, _, cumulative_time, _ in aggregated_stats
),
default=0,
)
total_unit, total_scale = self._determine_best_unit(max_total_time)
cumulative_unit, cumulative_scale = self._determine_best_unit(
max_cumulative_time
)
def _format_func_name(func):
"""Format function name with colors."""
return (
f"{ANSIColors.GREEN}{func[0]}{ANSIColors.RESET}:"
f"{ANSIColors.YELLOW}{func[1]}{ANSIColors.RESET}("
f"{ANSIColors.CYAN}{func[2]}{ANSIColors.RESET})"
)
def _print_top_functions(stats_list, title, key_func, format_line, n=3):
"""Print top N functions sorted by key_func with formatted output."""
print(f"\n{ANSIColors.BOLD_BLUE}{title}:{ANSIColors.RESET}")
sorted_stats = sorted(stats_list, key=key_func, reverse=True)
for stat in sorted_stats[:n]:
if line := format_line(stat):
print(f" {line}")
# Functions with highest direct/cumulative ratio (hot spots)
def format_hotspots(stat):
func, direct_calls, cumulative_calls, total_time, _, _ = stat
if direct_calls > 0 and cumulative_calls > 0:
ratio = direct_calls / cumulative_calls
direct_pct = (
(direct_calls / total_samples * 100)
if total_samples > 0
else 0
)
return (
f"{ratio:.3f} direct/cumulative ratio, "
f"{direct_pct:.1f}% direct samples: {_format_func_name(func)}"
)
return None
_print_top_functions(
aggregated_stats,
"Functions with Highest Direct/Cumulative Ratio (Hot Spots)",
key_func=lambda x: (x[1] / x[2]) if x[2] > 0 else 0,
format_line=format_hotspots,
)
# Functions with highest call frequency (cumulative/direct difference)
def format_call_frequency(stat):
func, direct_calls, cumulative_calls, total_time, _, _ = stat
if cumulative_calls > direct_calls:
call_frequency = cumulative_calls - direct_calls
cum_pct = (
(cumulative_calls / total_samples * 100)
if total_samples > 0
else 0
)
return (
f"{call_frequency:d} indirect calls, "
f"{cum_pct:.1f}% total stack presence: {_format_func_name(func)}"
)
return None
_print_top_functions(
aggregated_stats,
"Functions with Highest Call Frequency (Indirect Calls)",
key_func=lambda x: x[2] - x[1], # Sort by (cumulative - direct)
format_line=format_call_frequency,
)
# Functions with highest cumulative-to-direct multiplier (call magnification)
def format_call_magnification(stat):
func, direct_calls, cumulative_calls, total_time, _, _ = stat
if direct_calls > 0 and cumulative_calls > direct_calls:
multiplier = cumulative_calls / direct_calls
indirect_calls = cumulative_calls - direct_calls
return (
f"{multiplier:.1f}x call magnification, "
f"{indirect_calls:d} indirect calls from {direct_calls:d} direct: {_format_func_name(func)}"
)
return None
_print_top_functions(
aggregated_stats,
"Functions with Highest Call Magnification (Cumulative/Direct)",
key_func=lambda x: (x[2] / x[1])
if x[1] > 0
else 0, # Sort by cumulative/direct ratio
format_line=format_call_magnification,
)