erst profile

Export trace as pprof profile for gas-to-function mapping

Synthesize trace events into a pprof-compliant profile that maps gas consumption to functions.

Usage

erst profile [trace-file] [flags]

Description

The profile command converts Erst execution traces into the pprof profile format, which can be analyzed using Go’s profiling tools. This allows you to:

• Map gas consumption to specific functions
• Identify performance bottlenecks
• Analyze call graphs and hotspots
• Generate flamegraphs with standard tooling

The output is compatible with go tool pprof and other pprof-compatible analyzers.

Examples

Basic usage

erst profile execution.json -o gas.pb.gz

Arguments

trace-file · string

Path to the trace file to convert (JSON format)

Can be provided as positional argument or via --file flag.

Flags

--file · string

Trace file to load (alternative to positional argument)

Alias: -f

--output · string · default: "profile.pb.gz"

Output pprof file path

Alias: -o

Output format

The generated profile file is a gzip-compressed protobuf that contains:

• Sample data: Gas consumption per function call
• Call stacks: Complete execution paths
• Location info: Function names and contract addresses
• Metadata: Transaction hash, network, and timestamps

Analyzing profiles

Once you’ve generated a profile, use these commands to analyze it:

Interactive web UI

go tool pprof -http=:8080 gas.pb.gz

This launches a web interface with:

• Interactive flamegraph
• Call graph visualization
• Source code view (if debug symbols available)
• Top functions by gas consumption

Command-line analysis

Top functions

go tool pprof -top gas.pb.gz

Shows functions sorted by gas consumption.

Call graph

go tool pprof -tree gas.pb.gz

Displays hierarchical call tree.

Flamegraph

go tool pprof -raw gas.pb.gz | flamegraph.pl > flame.svg

Generates SVG flamegraph (requires flamegraph.pl).

Focus on function

go tool pprof -focus=transfer gas.pb.gz

Filters to specific function and callers/callees.

Use cases

Optimize gas consumption

Identify which functions consume the most gas:

erst profile execution.json -o gas.pb.gz
go tool pprof -top10 gas.pb.gz

Compare optimizations

Generate profiles before and after optimization:

# Before
erst profile before.json -o before.pb.gz

# After
erst profile after.json -o after.pb.gz

# Compare
go tool pprof -base=before.pb.gz after.pb.gz

Debug performance issues

Find unexpected bottlenecks:

erst profile execution.json -o gas.pb.gz
go tool pprof -http=:8080 gas.pb.gz
# Click "Flame Graph" in web UI

Related commands

• trace - View traces interactively
• debug - Generate traces from transactions
• compare - Compare gas usage between versions