Specify bounded storage, cleanup, and shared-service boundaries — Change one requirement

PART I

Warm-up

Reconnect with a useful idea before starting specify bounded storage, cleanup, and shared-service boundaries. In one or two sentences, describe the input, output or host boundary from the previous exercise that this lesson builds on. If you are arriving directly, skim the worked example first; there is no locked prerequisite.

A rough note is enough. You can revise it after the example.

PART II

Instruction & guided example

Adapt from per-owner to aggregate quota

Shared resources require scoped owners and permissions. A shared temporary service serves several consumers with separate identities, quotas and lifetimes. Sharing a storage backend does not merge resource authority. A host contract must validate handles, prevent cross-owner effects and say how aggregate pressure interacts with per-owner promises.

Shared service quota is 100 MB. Owner A uses 60 MB, owner B uses 20 MB. Each owner’s individual limit is 80 MB. B requests another 30 MB.

Draw owner→resource edges and trace one operation through identity, scope, quota and lifetime checks. Separate releasing one consumer’s reference from deleting an object still needed by others. Unknown sharing semantics must remain explicit requirements, not guessed reference-count or cancellation APIs. Worked case: B’s proposed use is 50 MB, within its individual limit, but aggregate use would be 110 MB and exceeds the shared limit by 10 MB. Both constraints must pass before admission.

Compare the tempting alternative: Checking only per-owner quota lets independently valid requests overcommit the shared service.

Worked reasoning and supplied artifact

// Paper trace / supplied exercise-host contract; no execution claimed.
// Shared service quota is 100 MB. Owner A uses 60 MB, owner B uses 20 MB. Each owner’s individual limit is 80 MB. B requests another 30 MB.
// B’s proposed use is 50 MB, within its individual limit, but aggregate use would be 110 MB and exceeds the shared limit by 10 MB. Both constraints must pass before admission.

Illustrative example from the proposed WillowScript design. The language and WUIX/WMATH/WDB/WAUDIO/WTMP services are not implemented in the supplied source. This site has no interpreter, VM or native host and does not execute or certify the snippet.

Try the guided change

Reconstruct the supplied worked case first: list its inputs, intermediate decisions and final artifact. Compare each row with the explanation and identify exactly where the rejected alternative fails. Then use the changed inputs in Part IV for independent work.

• Write the supplied inputs and initial state before following the example.
• Reconstruct each intermediate calculation or host decision, then compare with the worked artifact.
• Explain why the contrasting alternative fails before attempting the changed inputs in Part IV.

PART III

Take a breather

Step back after the guided example. Look away from the screen, stretch, or reread your prediction. This is an optional learning pause, not a timer or an assessment gate.

When you return, try to name the lesson’s key idea without copying its wording. If that feels difficult, return to Part II and trace one line rather than restarting the entire lesson.

PART IV

Independent practice

Project context: Temporary asset workflow. Build a small, understandable change around specify bounded storage, cleanup, and shared-service boundaries.

Calculate requests of 10, 20 and 30 MB for B, then describe an atomic admission guarantee if owners allocate concurrently.

What to produce

A dual-quota decision table and a concurrency requirement.

• State the intended behavior in a sentence before editing.
• Use only source-backed syntax and the host services whose contract you have been given.
• Record a normal case and a boundary or unavailable-resource case.
• Label hand predictions separately from anything actually measured in a supplied toolchain.

Syntax colors are a reading aid, not a compiler. The line you are editing stays uncolored until you move to a different line; capitalization is never changed. Drafts stay on this browser and code is not executed.

import wdb;
domain Inventory {
    const lowStock = wdb.query({
        from: products,
        select: [id, name, stock],
        where: [[ stock < 10 ]],
        order: { by: stock, direction: ascending }
    });
}

PART V

Self-check

Use this check to notice what to revisit. It does not award a private course grade, block another page or claim to verify compiled code. Every answer has a learning explanation.

You may keep exploring even if you are unsure. Use the hint, compare the trace, and revise your explanation.

PART VI

Recap & small task

Bring the idea back to the mod feature you are building. A useful recap connects the mechanism to a decision you can make in your own code.

• Adapt from per-owner to aggregate quota
• Calculate requests of 10, 20 and 30 MB for B, then describe an atomic admission guarantee if owners allocate concurrently.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Name both limits an admission decision must check.

This marks your personal practice record only. It is not a certification or an official workspace assessment.