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fix(publication): converge consumer lock helpers #47

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Merged
rynfar merged 1 commit into from
Sep 2, 2026
Merged

fix(publication): converge consumer lock helpers #47

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53 changes: 51 additions & 2 deletions scripts/lib/pylon-consumer-lock.mjs
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Original file line number Diff line number Diff line change
Expand Up @@ -1185,6 +1185,42 @@ async function readApplied(context, claim, terminal, options) {
);
}

async function authenticateAppliedCommit(context, claim, terminal, options) {
for (const transaction of terminal.transactions) {
await revalidateAuthority(context, "read-applied-transition", options);
const existing = await readExactMetadata(
transitionPath(context, transaction.baseDigest),
options.metadataMaxBytes,
(value) => validateTransaction(value, transaction.baseDigest, options.stateMaxBytes).value,
"Consumer high-water applied transaction",
options,
);
if (existing === null || !metadataBytes(existing).equals(metadataBytes(transaction))) {
throw new Error("Consumer high-water applied marker does not authenticate its exact immutable transaction chain.");
}
}
const tip = await walkTransactions(context, options);
const terminalDigest = terminal.transactions.at(-1).candidateDigest;
if (tip.tipDigest !== terminalDigest) {
await revalidateAuthority(context, "read-applied-continuation", options);
const continuation = await readExactMetadata(
transitionPath(context, terminalDigest),
options.metadataMaxBytes,
(value) => validateTransaction(value, terminalDigest, options.stateMaxBytes).value,
"Consumer high-water applied transaction continuation",
options,
);
if (continuation === null) {
throw new Error("Consumer high-water applied marker does not authenticate its exact terminal digest.");
}
}
const repairedTip = await repairProjection(context, tip, options, claim);
const projection = await readProjection(context, "read-applied-projection", options);
if (projection.malformed || projection.sha256 !== repairedTip.tipDigest) {
throw new Error("Consumer high-water applied marker does not authenticate the current immutable tip and projection.");
}
}

async function finishCommitAtAuthenticatedDescendant(context, options) {
const scan = await scanJournalRoot(context.statePath, context.journalDirectory, options);
const head = scan.head;
Expand All @@ -1206,7 +1242,11 @@ async function finishCommitAtAuthenticatedDescendant(context, options) {
async function finishCommit(context, claim, terminal, options) {
for (let attempt = 0; attempt < PROJECTION_RETRY_LIMIT; attempt += 1) {
try {
await readApplied(context, claim, terminal, options);
const applied = await readApplied(context, claim, terminal, options);
if (applied !== null) {
await authenticateAppliedCommit(context, claim, terminal, options);
return;
}
for (const transaction of terminal.transactions) await publishTransition(context, transaction, claim, options);
const tip = await walkTransactions(context, options);
await repairProjection(context, tip, options, claim);
Expand Down Expand Up @@ -2785,7 +2825,16 @@ async function runRotation(statePath, rawOptions) {
const initialScan = await scanEpoch(context, options);
const completed = await recoverCompletedCurrentRotation(context, initialScan, options);
if (completed) return completed;
const frontier = await resolveOperationFrontier(context, options);
const expectedIntent = rotationIntentFor(context, await effectiveTip(context, options));
let frontier;
try {
frontier = await resolveOperationFrontier(context, options);
} catch (error) {
if (error?.message !== "Consumer high-water journal epoch changed and fenced a paused writer.") throw error;
const completedResult = await completedRotationResult(context, expectedIntent, options);
if (completedResult) return completedResult;
throw error;
}
if (frontier.rotated) continue;
if (frontier.active) {
throw new Error("Consumer high-water state is actively locked; rotation will retry after the claim quiesces.");
Expand Down
53 changes: 53 additions & 0 deletions scripts/pylon-publication.test.mjs
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Original file line number Diff line number Diff line change
Expand Up @@ -2348,6 +2348,24 @@ test("consumer state locking, recovery, transaction fencing, durability, and pat
);
}

const appliedReceiptPath = join(fixture, "already-applied-rotation.json");
await withConsumerStateLock(appliedReceiptPath, async (_path, transaction) => {
await transaction.commitState(bytes("already-applied-anchor"));
}, manualRuntime({ value: 1 }));
const redundantAppliedWrites = [];
const appliedReceiptRotation = await rotateConsumerStateJournal(appliedReceiptPath, manualRuntime({ value: 2 }, {
afterFileSync: async ({ kind }) => {
if (!["transition", "applied"].includes(kind)) return;
redundantAppliedWrites.push(kind);
throw new Error(`already-applied claim attempted a redundant ${kind} publication`);
},
}));
assert.deepEqual(redundantAppliedWrites, []);
assert.deepEqual(appliedReceiptRotation, {
epoch: 2,
tipSha256: sha256Bytes(bytes("already-applied-anchor")),
});

const legacyRotationPath = join(fixture, "legacy-rotation.json");
writeFileSync(legacyRotationPath, bytes("legacy-anchor"), { mode: 0o600 });
assert.equal((await rotateConsumerStateJournal(legacyRotationPath, manualRuntime({ value: 1 }))).epoch, 2);
Expand Down Expand Up @@ -2599,6 +2617,41 @@ test("consumer state locking, recovery, transaction fencing, durability, and pat
rmSync(join(liveTemporaryDirectory, liveTemporaryName));
assert.equal((await rotateConsumerStateJournal(liveTemporaryPath, manualRuntime({ value: 4 }))).epoch, 2);

const frontierHandoffPath = join(fixture, "frontier-completion-handoff.json");
await withConsumerStateLock(frontierHandoffPath, async (_path, transaction) => {
await transaction.commitState(bytes("frontier-handoff-anchor"));
}, manualRuntime({ value: 1 }));
const firstSecondScanReached = deferred();
const secondSecondScanReached = deferred();
const releaseFirstSecondScan = deferred();
const releaseSecondSecondScan = deferred();
const rotationAtSecondScanBarrier = (reached, release) => {
let claimScans = 0;
return rotateConsumerStateJournal(frontierHandoffPath, manualRuntime({ value: 2 }, {
beforePathOperation: async ({ operation }) => {
if (operation !== "scan-claims") return;
claimScans += 1;
if (claimScans !== 2) return;
reached.resolve();
await release.promise;
},
}));
};
const frontierWinner = rotationAtSecondScanBarrier(firstSecondScanReached, releaseFirstSecondScan);
const frontierResumed = rotationAtSecondScanBarrier(secondSecondScanReached, releaseSecondSecondScan);
await Promise.all([firstSecondScanReached.promise, secondSecondScanReached.promise]);
releaseFirstSecondScan.resolve();
const frontierWinnerResult = await frontierWinner;
releaseSecondSecondScan.resolve();
const frontierResumedResult = await frontierResumed;
assert.equal(Buffer.from(JSON.stringify(frontierResumedResult)).equals(
Buffer.from(JSON.stringify(frontierWinnerResult)),
), true, "the stale rotator returns the winner's byte-identical completion receipt");
assert.deepEqual(frontierWinnerResult, {
epoch: 2,
tipSha256: sha256Bytes(bytes("frontier-handoff-anchor")),
});

const concurrentRotationPath = join(fixture, "concurrent-rotation.json");
await withConsumerStateLock(concurrentRotationPath, async (_path, transaction) => {
await transaction.commitState(bytes("concurrent-anchor"));
Expand Down
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