---
title: "wasi-freshness — Mova code model"
description: "Mova code model of wasi-host/tests/mlab.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/wasi-host/tests/mlab.rs.groupant/wasi-freshness.groupant/"
---
Elamur: [Mova](https://md.mova.elamur.ai/free/en/) · [Dictionary](https://md.dictionary.elamur.ai/free/en/) · [Research](https://md.research.elamur.ai/free/en/) · **Groupants**

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# wasi-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

- **kind:** groupant_fragment
- **status:** partial source bound model
- **source:** [`wasi-host/tests/mlab.rs`](https://github.com/ElamurAI/mova-free/blob/main/wasi-host/tests/mlab.rs)
- **source SHA-256:** `e3b35b1a315b6d99…`
- **covers:** 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. (bytes 1210–2057)
- **part of:** [wasi-mlab-tests](https://md.groupants.elamur.ai/free/en/mova/wasi-host/tests/mlab.rs.groupant/)
- **repository folder:** [`wasi-host/tests/mlab.rs.groupant/wasi-freshness.groupant`](https://github.com/ElamurAI/mova-free/tree/main/wasi-host/tests/mlab.rs.groupant/wasi-freshness.groupant)
- **repository commit:** `855da7bd4a7b`

> **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](#approximant) |
| **ast** | partial | `../syntax.json` |
| **cost** | symbolic source derived | [invariant](#invariant) |
| **descriptant** | present | [descriptant](#descriptant) |
| **invariant** | partial | [invariant](#invariant) |
| **tests** | executed bounded checks | [tests](#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](#behavior-complement) |
| `reverse_reconstruction` | reverse_reconstruction | partial source derived model | [reverse_reconstruction](#reverse-reconstruction) |
| `empty_tree` | empty_tree | partial source derived model | [empty_tree](#empty-tree) |
| `timestamp_ties` | timestamp_ties | partial source derived model | [timestamp_ties](#timestamp-ties) |
| `error_partition` | error_partition | partial source derived model | [error_partition](#error-partition) |
| `isolated_oracle` | isolated_oracle | partial source derived model | [isolated_oracle](#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.