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

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Usage

erst profile [trace-file] [flags]

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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.

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Examples

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

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Arguments

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trace-file
string
Path to the trace file to convert (JSON format)Can be provided as positional argument or via --file flag.

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Flags

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--file
string
Trace file to load (alternative to positional argument)Alias: -f
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--output
string
default:"profile.pb.gz"
Output pprof file pathAlias: -o

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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

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Analyzing profiles

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

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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

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Command-line analysis

go tool pprof -top gas.pb.gz
Shows functions sorted by gas consumption.

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Use cases

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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

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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

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