storage-cost.md

Storage Cost Benchmarks

This document tracks the resource-regression guard for the attester allowlist as it scales.

Enforced checkpoints

large_attester_allowlist_load records the budget of add_attester after the allowlist reaches each checkpoint and fails if either ceiling is exceeded.

Operation	Attesters	Maximum CPU instructions	Maximum memory bytes
add_attester	10	2,000,000	1,000,000
add_attester	100	2,000,000	1,000,000
add_attester	1,000	2,000,000	1,000,000

Methodology

The test initializes attester-registry, adds 1,000 distinct addresses, and reads Budget::cpu_instruction_cost and Budget::memory_bytes_cost immediately after additions 10, 100, and 1,000. Soroban resets metering before each top-level invocation, so each checkpoint measures one add_attester call with the allowlist at that size. This catches a size-dependent scan without conflating the result with the cost of populating the preceding entries.

These are native-test regression measurements, not fee estimates. Native registration omits Wasm execution, transaction-envelope processing, and some ledger work, so the values must not be used to predict production fees.

Run the test and print its measured values with:

cargo test -p attester-registry large_attester_allowlist_load -- --nocapture

Last source verification: contract commit 82f7473, with soroban-sdk 27.0.0 from the workspace lockfile. Update this reference and review the ceilings whenever contract behavior or the pinned SDK cost model changes.