JIT Costing: The Definitive PR#876
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Introduce the JIT cost accumulator and limit on the interpreter Context (jit_cost / jit_cost_limit fields; add_jit_cost / add_per_item_jit_cost / jit_cost_value / reset_jit_cost; CostLimitExceeded), wire the supporting cost_accum and error plumbing, and initialise the new fields in every Context constructor (arbitrary + wallet::signing::make_context). Remove the dead pre-costing costs.rs stub (zero consumers). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge each node's Scala base cost (FixedCost) at eval time: the per-Expr arms (Const=5, Global=5, Context=1), the ~40 single-cost eval ops, GlobalVars (Height=26, Self/Outputs/Inputs/GroupGenerator=10, MinerPubKey=20), method_call, and ConcreteCollection=20. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge each builtin-type method's Scala FixedCost in its EVAL_FN: Context (dataInputs/headers/preHeader/lastBlockUtxoRootHash 15, selfBoxIndex/minerPubKey 20, getVarFromInput 10), Box (value 8, getReg 50, tokens 15), Header/PreHeader fields (10 each; Header.checkPow 700), GroupElement, AvlTree (15 each; updateOperations 45, updateDigest 40), and Global generic methods (groupGenerator/xor/fromBigEndianBytes 10, some/none 5, deserialize per-item 100/32/32). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge each BinOp's Scala per-kind cost and route equality through DataValueComparer (per-element comparison costs). Includes the folded SigmaProp equality conformance fix: SigmaProp == SigmaProp now charges per Scala equalSigmaBoolean (ProveDlog 174 / ProveDHTuple 690) instead of the flat catch-all 3, matching the JVM equalDataValues on a rare type-valid path. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Cost reduce_to_crypto: accumulate JIT cost as a delta from the caller's accumulator (cumulative across inputs, enabling per-tx limit enforcement), preserve ConstPlaceholders for cost eval via ErgoTree::proposition_for_cost_eval (+ Constant.resolved / Expr::resolve_placeholders), short-circuit trivial SigmaProp-constant trees (P2PK) at Scala's EvalSigmaPropConstant flat 50, and propagate the accumulated cost through the verifier (crypto_cost). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Enforce the per-transaction JIT cost limit cumulatively across all transaction inputs: derive the cost limit from chain parameters, share one Context accumulator across the per-input reduce_to_crypto calls so their costs sum, and fail verification when the cumulative cost exceeds the limit. Threaded through tx_context (validate), parameters, ergo_transaction, and the ergo-lib-wasm binding. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge Coll.indexOf its Scala cost: PerItemCost(20,10,2) over the iterations actually performed, plus the element-type equality cost per comparison via DataValueComparer::eq_with_cost. A bare == previously left both uncharged. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Introduce eval_lambda_1arg, the shared collection-HOF lambda helper that charges ADD_TO_ENV_COST=5 per binding, and route flatMap through it (charged once per input element). Also charge flatMap's output-length PerItemCost(60,10,8) over the flattened result, matching Scala flatMap_eval. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge ADD_TO_ENV_COST per value binding in Apply (FuncValue invocation) and BlockValue (val definitions), matching Scala's per-binding AddToEnvironment. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Route the collection HOFs map/filter/fold/exists/forall through eval_lambda_1arg (ADD_TO_ENV charged per element) and charge their Scala per-iteration costs. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
…Many/reverse/startsWith/endsWith/get) Charge the Scala PerItemCost for the remaining Coll methods: zip, indices, patch, updated, updateMany, reverse, startsWith, endsWith, get. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge SubstConstants its Scala cost scaled by the number of template constants substituted. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge Coll.slice its Scala cost over the requested (to - from) range. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge SigmaProp.propBytes its Scala cost scaled by the SigmaBoolean proposition node count (adds SigmaBoolean::size()). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge And and Blake2b256 their per-collection-element Scala costs, and charge boolean-constant collections N*5 per element to match the Exprs form. Adds empty-collection regression tests (and_empty, calc_blake2b256_empty, bool_constants_coll). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge the Scala FixedCost for the v6.0 numeric and UnsignedBigInt methods. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge Global.encodeNbits=25 / decodeNbits=50 (FixedCost) and powHit's PowHitCostKind formula 500 + (k+1) * (totalLen/128 + 1) * 7, with regression tests. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Add a SigmaByteWriter serialize-cost accumulator (enable_serialize_cost_tracking / serialize_cost / add_put_byte_cost / add_put_numeric_cost / add_put_chunk_cost) and charge the direct DataSerializer types: Boolean/Byte = PutByte, Short/Int/Long and all length prefixes = PutNumeric, String/Coll bytes = PutChunk, Opt tag = PutByte. Wire Global.serialize to meter the writer puts (StartWriterCost 10 + tracked put costs). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge the serialize put-cost for GroupElement (PutChunk over GROUP_SIZE), SigmaBoolean/SigmaProp, and BigInt256/UnsignedBigInt256 sigma_serialize. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge the serialize put-cost for ErgoBox: the register type-code prefix (TypeCode::sigma_serialize PutByte), creationHeight, value, and TxId, matching Scala's box serialization metering. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge the AvlTree serialize put-cost (digest + flags + key/value-length fields) during Global.serialize. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge the PutByte cost for the SType fast-path combined type-code arms (Coll/Nested/Option/Tuple-pair over primitives), with a regression test. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Charge the Header serialize put-cost by mirroring the JVM put sequence (HeaderWithoutPow + AutolykosSolution; Header lives in ergo-chain-types and can't reach the cost sink), reaching the blessed v6 Global.serialize[Header] = 333. Adds the cross-type serialize_charges_writer_costkinds regression test covering byte/numeric/coll (c17), GroupElement/UnsignedBigInt (c18), AvlTree (c20) and Header. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Add the ergo-lib cost_parity integration test replaying mainnet blocks 700000-700060 and asserting each transaction's computed JIT cost matches the node's recorded cost (78 vectors), pinning the full costing model to consensus. Includes the headers / transactions / tx_costs test vectors. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This was referenced Jun 3, 2026
Scala NumericCastCostKind bills both SBigInt and SUnsignedBigInt at JitCost(30) (others 10); Upcast/Downcast were billing UnsignedBigInt the else-branch 10. Mirror the oracle so the JIT cost of a numeric cast to UnsignedBigInt matches the JVM. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Closes #193.
Ports JIT costing from sigmastate-interpreter (
direct-tree-eval): each IR nodeaccumulates its Scala cost into the interpreter
Contextduring evaluation, theper-transaction cost limit is enforced cumulatively across inputs, and per-element
equality costs (
DataValueComparer) andSigmaByteWriterserialize costs arecharged. A
cost_paritytest replays mainnet blocks 700000–700060 and asserts everytransaction's computed JIT cost equals the node's recorded cost (78 vectors).
Supersedes #854. Same logical change, re-sliced from #854's tangled history into
24 dependency-ordered, individually-green commits — each builds and passes the
ergotree-interpreter/ergotree-irsuites pluscargo clippy --all-features --all-targets -D warnings. One conformance fix is folded in:SigmaProp == SigmaPropnow charges per Scala
equalSigmaBoolean(ProveDlog 174 / ProveDHTuple 690) instead ofthe flat catch-all 3.
Relationship to #858 (lazy constant resolution)
Independent PR, overlapping in
reduce_to_crypto/ConstPlaceholderhandling — whichevermerges first, the other takes a mechanical rebase. This PR resolves segregated
ConstPlaceholderviaConstantPlaceholder::resolved(populated byErgoTree::proposition_for_cost_eval) and charges itJitCost(1); #858 introducesContext.constantslazy resolution. Reconciliation either way: theConstPlaceholderarm ends up charging 1 JitCost and resolving via
ctx.constants, dropping thisPR's
resolved-field machinery as redundant. Worked reconciliation on theergo-node-integrationbranch (9094f693); full rebase recipe pinned on #858.