Module trace 

Trace log parsing and Chrome Trace Format export.

This module provides tools for analyzing wt-trace log output to understand where time is spent during command execution.

Features

• Trace parsing: Parse wt-trace log lines into structured entries
• Chrome Trace Format: Export for chrome://tracing or Perfetto visualization
• SQL analysis: Use Perfetto’s trace_processor for queries

Usage

# Generate Chrome Trace Format
RUST_LOG=debug wt list 2>&1 | grep wt-trace | cargo run -p wt-perf -- trace > trace.json

# Visualize: open trace.json in chrome://tracing or https://ui.perfetto.dev

# Analyze with SQL (requires: curl -LO https://get.perfetto.dev/trace_processor)
trace_processor trace.json -Q 'SELECT name, COUNT(*), SUM(dur)/1e6 as ms FROM slice GROUP BY name'

# Find milestone events (instant events have dur=0)
trace_processor trace.json -Q 'SELECT name, ts/1e6 as ms FROM slice WHERE dur = 0'

# Time from start to skeleton render
trace_processor trace.json -Q "
  SELECT (skeleton.ts - start.ts)/1e6 as skeleton_ms
  FROM slice start, slice skeleton
  WHERE start.name = 'List collect started'
    AND skeleton.name = 'Skeleton rendered'"

Re-exports

pub use chrome::to_chrome_trace;

pub use parse::TraceEntry;

pub use parse::TraceEntryKind;

pub use parse::TraceResult;

pub use parse::parse_lines;

Modules

chrome

Chrome Trace Format output for concurrency visualization.

parse

Parse wt-trace log lines into structured entries.