Elamur Groupantswasi-freshness
The groupant beside wasi-host/tests/mlab.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.
Facts
Implementation material. A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.
Components
| component | label | where |
|---|---|---|
| approximant | partial | approximant |
| ast | partial | ../syntax.json |
| cost | symbolic source derived | invariant |
| descriptant | present | descriptant |
| invariant | partial | invariant |
| tests | executed bounded checks | tests |
Obernants
The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.
| id | type | label | where |
|---|---|---|---|
behavior_complement | behavior_complement | partial source derived model | behavior_complement |
reverse_reconstruction | reverse_reconstruction | partial source derived model | reverse_reconstruction |
empty_tree | empty_tree | partial source derived model | empty_tree |
timestamp_ties | timestamp_ties | partial source derived model | timestamp_ties |
error_partition | error_partition | partial source derived model | error_partition |
isolated_oracle | isolated_oracle | partial source derived model | isolated_oracle |
Model text
descriptant
wasi-freshness
newest_mtime recursively computes max of leaf modified times starting UNIX_EPOCH; directories contribute recursive leaves, not directory timestamp. read_dir errors unwrap; entry errors are flattened away. wasm_path checks metadata and two source trees then returns artifact path.
Epoch 2026-10-31
Prospective review recorded before edits. Source review found late output FAULT effects and weaker-than-capability rights metadata; these are modeled as current behavior rather than silently repaired. Only bounded new test blocks were added; production code remains unchanged. Actual finite results and exact restoration receipts live under $MOVA_DATA/runs/octopus-wave31-wasi-2026-10-31. No full mlab guest, frozen suite, GPU or corpus run. This node retains its scoped observations for future refinement.
approximant
Forward relation
newest_mtime recursively computes max of leaf modified times starting UNIX_EPOCH; directories contribute recursive leaves, not directory timestamp. read_dir errors unwrap; entry errors are flattened away. wasm_path checks metadata and two source trees then returns artifact path.
Scope: wasi-freshness. State and transitions follow the authoritative source, including partial effects before errors. No executable approximate replacement is attached: categorical errno/effects and module execution lack a useful validated percentage metric; future numerical profiles may only use1/2/5/10% caps after domain/reference evidence.
invariant
Invariant and cost
newest_mtime recursively computes max of leaf modified times starting UNIX_EPOCH; directories contribute recursive leaves, not directory timestamp. read_dir errors unwrap; entry errors are flattened away. wasm_path checks metadata and two source trees then returns artifact path.
The invariant is conditional on the admitted transition: With readable leaves and no pre-epoch timestamps, returned maximum cannot be below an observed leaf time. Empty directory excludes any non-epoch result.
Cost: O(entries) metadata calls and depth stack; follows is_dir semantics so cycles/resource errors not bounded by helper itself.
No wall-time gain, universal resource bound or atomic rollback is inferred. External Vfs/wasmi/native-mlab work remains separately charged.
models
Typed model catalog
behavior_complement
Subject: wasi-host/tests/mlab.rs at SHA-256 e3b35b1a315b6d995fd3cb8e590209d9f57141b89d9def132cd733f31d8f2db8, scope wasi-freshness. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: With readable leaves and no pre-epoch timestamps, returned maximum cannot be below an observed leaf time. Empty directory excludes any non-epoch result.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
reverse_reconstruction
Subject: wasi-host/tests/mlab.rs at SHA-256 e3b35b1a315b6d995fd3cb8e590209d9f57141b89d9def132cd733f31d8f2db8, scope wasi-freshness. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Maximum mtime constrains all observed leaves<=max and some attaining max unless empty; directory layout, file bytes and ignored entry errors are not recoverable.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
empty_tree
Subject: wasi-host/tests/mlab.rs at SHA-256 e3b35b1a315b6d995fd3cb8e590209d9f57141b89d9def132cd733f31d8f2db8, scope wasi-freshness. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Empty tree returns UNIX_EPOCH regardless directory modified time.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
timestamp_ties
Subject: wasi-host/tests/mlab.rs at SHA-256 e3b35b1a315b6d995fd3cb8e590209d9f57141b89d9def132cd733f31d8f2db8, scope wasi-freshness. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Equal newest file times share max; no unique newest path returned.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
error_partition
Subject: wasi-host/tests/mlab.rs at SHA-256 e3b35b1a315b6d995fd3cb8e590209d9f57141b89d9def132cd733f31d8f2db8, scope wasi-freshness. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: read_dir/metadata/modified panic; individual read_dir entry errors dropped by flatten, so not complete error reporting.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
isolated_oracle
Subject: wasi-host/tests/mlab.rs at SHA-256 e3b35b1a315b6d995fd3cb8e590209d9f57141b89d9def132cd733f31d8f2db8, scope wasi-freshness. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Two explicitly written files yield oracle max(metadata(a),metadata(sub/b)); cleanup after caught assertion panic.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
tests
Checks and limits
Named actual-source tests run twice per debug/release; exact commands and numeric statuses retained externally. Test success is finite evidence only.
Exact names: wave31_newest_mtime_isolated_tree.
Memory tests bypass linker ABI; tiny empty/unreachable guests exercise engine outcomes only. The CLI test uses isolated import/export/journal fixtures.
Five compiled production/helper-source controls: append offset, virtual clock advance, trap status, CLI export gate and newest-mtime max. Each compiles, fails its selected assertion, restores exact original bytes and passes again. These controls cover their target relations, not every node. No assertion-only mutants. See external source-test-map.json, native-commands.json, verify.rs and numeric/raw receipts in $MOVA_DATA/runs/octopus-wave31-wasi-2026-10-31. The example main and frozen mlab paths are never executed.
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