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Prevent competing GPT first impressions and resize PUC shells #1079

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10 changes: 7 additions & 3 deletions crates/trusted-server-core/src/integrations/gpt.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1246,12 +1246,16 @@ mod tests {
"should set ts_initial sentinel"
);
assert!(
!combined.contains("addEventListener(\"slotRenderEnded\""),
"inline bootstrap cannot prove TS creative rendering from GPT slotRenderEnded"
combined.contains("addEventListener(\"slotRequested\""),
"should observe publisher GPT requests before delayed adInit"
);
assert!(
combined.contains("addEventListener(\"slotRenderEnded\""),
"should observe publisher GPT renders before delayed adInit"
);
assert!(
!combined.contains("sendBeacon"),
"inline bootstrap must not fire win/billing beacons from GPT slotRenderEnded"
"inline bootstrap lifecycle ownership must not fire win/billing beacons"
);
assert!(
!combined.contains("getTargeting(\"hb_adid\")"),
Expand Down
288 changes: 273 additions & 15 deletions crates/trusted-server-core/src/integrations/gpt_bootstrap.js
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -102,6 +102,137 @@
pubads.__tsInitialLoadHooked = true;
});

var FIRST_IMPRESSION_LEASE_MS = 5000;

@prk-Jr prk-Jr Aug 27, 2026

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⛏ nitpick — Three independent 5000 ms constants with no cross-reference.

FIRST_IMPRESSION_LEASE_MS is duplicated here and in crates/trusted-server-js/lib/src/core/first_impression.ts:10, and it has to match PENDING_PUBLISHER_DELIVERY_TTL_MS in crates/trusted-server-js/lib/src/integrations/prebid/index.ts:140 for the token timers to line up. The diff also dropped the existing // Keep in sync with TS_INITIAL_TARGETING_KEY in index.ts comment when ts_initial moved into bootstrapTargeting, so the bootstrap now has no sync markers at all.

Suggested change
var FIRST_IMPRESSION_LEASE_MS = 5000;
// Keep in sync with FIRST_IMPRESSION_LEASE_MS in
// crates/trusted-server-js/lib/src/core/first_impression.ts, and with
// PENDING_PUBLISHER_DELIVERY_TTL_MS in
// crates/trusted-server-js/lib/src/integrations/prebid/index.ts, which bounds
// the publisher-auction tokens this lease arbitrates against.
var FIRST_IMPRESSION_LEASE_MS = 5000;

Verified with this suggestion applied alone and batched with the other one: cargo fmt --all -- --check clean, cargo test -p trusted-server-core --target aarch64-apple-darwin integrations::gpt 47/47, and the post-verify patch snapshot byte-identical to the approved patch. Note GPT_BOOTSTRAP_JS is injected unminified via format!("<script>{}</script>", ...), so this adds roughly 250 bytes to the inline head script — consistent with the comment density already in this file.


function firstImpressionState(now) {
var generation = ts.navGeneration || 0;
if (
!ts.firstImpression ||
ts.firstImpression.generation !== generation
) {
ts.firstImpression = {
generation: generation,
nextToken: 0,
slots: {},
fallbackSlots: {},
};
}
var state = ts.firstImpression;
state.slots = state.slots || {};
state.fallbackSlots = state.fallbackSlots || {};
Object.keys(state.slots).forEach(function (elementId) {
var claim = state.slots[elementId];
if (
claim.generation !== generation ||
claim.slotElementId !== elementId ||
claim.element !== document.getElementById(elementId) ||
!claim.element.isConnected
) {
delete state.slots[elementId];
return;
}
Object.keys(claim.publisherAuctions || {}).forEach(function (token) {
if (claim.publisherAuctions[token].expiresAt <= now) {
delete claim.publisherAuctions[token];
}
});
if (
claim.owner === "publisher" &&
(claim.phase === "auctioning" || claim.phase === "delivery_pending") &&
Object.keys(claim.publisherAuctions || {}).length === 0 &&
claim.expiresAt <= now
) {
delete state.slots[elementId];
}
});
Object.keys(state.fallbackSlots).forEach(function (elementId) {
var element = state.fallbackSlots[elementId];
if (
!element.isConnected ||
element.id !== elementId ||
document.getElementById(elementId) !== element
) {
delete state.fallbackSlots[elementId];
}
});
return state;
}

function firstImpressionClaim(element) {
return firstImpressionState(Date.now()).slots[element.id];
}

function claimFirstImpressionForTrustedServer(element) {
var now = Date.now();
var state = firstImpressionState(now);
if (state.slots[element.id]) return null;
var claim = {
generation: state.generation,
slotElementId: element.id,
element: element,
owner: "trusted_server",
phase: "delivery_pending",
expiresAt: now + FIRST_IMPRESSION_LEASE_MS,
publisherAuctions: {},
};
state.slots[element.id] = claim;
return claim;
}

function releaseTrustedServerFirstImpressionClaim(element, claim) {
var state = firstImpressionState(Date.now());
if (
state.slots[element.id] === claim &&
claim.owner === "trusted_server" &&
claim.phase === "delivery_pending" &&
Object.keys(claim.publisherAuctions || {}).length === 0
) {
delete state.slots[element.id];
}
}

function installFirstImpressionListeners() {
if (ts.firstImpressionListenersInstalled) return;
tag.cmd.push(function () {
if (ts.firstImpressionListenersInstalled) return;
var pubads = window.googletag.pubads();
if (!pubads || typeof pubads.addEventListener !== "function") return;
var observe = function (phase) {
return function (event) {
var elementId =
event.slot && event.slot.getSlotElementId
? event.slot.getSlotElementId()
: "";
var element = elementId && document.getElementById(elementId);
if (!element) return;
var state = firstImpressionState(Date.now());
var claim = state.slots[elementId];
if (!claim) {
claim = state.slots[elementId] = {
generation: state.generation,
slotElementId: elementId,
element: element,
owner: "publisher",
phase: phase,
expiresAt: Number.POSITIVE_INFINITY,
publisherAuctions: {},
};
Comment on lines +211 to +219
} else {
claim.phase = phase;
if (claim.owner === "publisher") {
claim.expiresAt = Number.POSITIVE_INFINITY;
}
}
};
};
pubads.addEventListener("slotRequested", observe("requested"));
pubads.addEventListener("slotRenderEnded", observe("rendered"));
ts.firstImpressionListenersInstalled = true;
});
}

installFirstImpressionListeners();

// Minimal fallback for tsjs.scheduleInitialAdInit, mirroring the bundle's
// hydration-safe scheduler in
// crates/trusted-server-js/lib/src/integrations/gpt/index.ts: the </body>
Expand Down Expand Up @@ -412,6 +543,129 @@

installSlotHandoff();

function bootstrapTargeting(slot, bid) {
var targeting = Object.assign({}, slot.targeting || {});
["hb_pb", "hb_bidder", "hb_adid", "hb_cache_host", "hb_cache_path"].forEach(
function (key) {
if (bid[key]) targeting[key] = String(bid[key]);
},
);
targeting.ts_initial = "1";
return targeting;
}

function scheduleFirstImpressionFallback(slot, bid, element, generation) {
var state = firstImpressionState(Date.now());
if (state.fallbackSlots[element.id]) return;
state.fallbackSlots[element.id] = element;

var retry = function () {
if (
(ts.navGeneration || 0) !== generation ||
!element.isConnected ||
document.getElementById(element.id) !== element
) {
return;
}
var claim = firstImpressionClaim(element);
if (claim) {
if (
claim.owner !== "publisher" ||
claim.phase === "requested" ||
claim.phase === "rendered"
) {
return;
}
var delay = Math.max(0, claim.expiresAt - Date.now());
if (delay > 0) {
window.setTimeout(retry, delay + 1);
return;
}
}

tag.cmd.push(function () {
if (
(ts.navGeneration || 0) !== generation ||
!element.isConnected ||
document.getElementById(element.id) !== element
) {
return;
}
var fallbackClaim = claimFirstImpressionForTrustedServer(element);
if (!fallbackClaim) return;
var pubads = window.googletag.pubads();
var existingSlots = pubads.getSlots ? pubads.getSlots() : [];
var gptSlot =
existingSlots.find(function (candidate) {
return candidate.getSlotElementId() === element.id;
}) || null;
var tsOwned = false;
if (!gptSlot) {
gptSlot = runHandoffInternal(function () {
return window.googletag.defineSlot(
slot.gam_unit_path,
slot.formats,
element.id,
);
});
if (!gptSlot) {
releaseTrustedServerFirstImpressionClaim(element, fallbackClaim);
return;
}
gptSlot.addService(pubads);
tsOwned = true;
ts.gptSlotHandoffs = ts.gptSlotHandoffs || {};
ts.gptSlotHandoffs[element.id] = {
gamUnitPath: slot.gam_unit_path,
formats: slot.formats,
divIdPrefix: slot.div_id,
slotElementId: element.id,
publisherClaimed: false,
suppressPublisherDisplay: false,
suppressPublisherRefresh: false,
};
}

var targeting = bootstrapTargeting(slot, bid);
Object.entries(targeting).forEach(function (entry) {
gptSlot.setTargeting(entry[0], entry[1]);
});
fallbackClaim.targeting = targeting;
var slotElementId = gptSlot.getSlotElementId() || element.id;
ts.divToSlotId = ts.divToSlotId || {};
ts.divToSlotId[element.id] = slot.id;
ts.divToSlotId[slotElementId] = slot.id;
if (tsOwned) {
ts.prevGptSlots = ts.prevGptSlots || [];
ts.prevGptSlots.push(gptSlot);
}
if (!ts.servicesEnabled) {
pubads.enableSingleRequest();
window.googletag.enableServices();
ts.servicesEnabled = true;
}
if (tsOwned) {
runHandoffInternal(function () {
window.googletag.display(slotElementId);
});
}
syncInitialLoadDisabled(window.googletag);
if (!tsOwned || ts.gptInitialLoadDisabled) {
ts.adInitRefreshInProgress = true;
try {
runHandoffInternal(function () {
pubads.refresh([gptSlot]);
});
} finally {
ts.adInitRefreshInProgress = false;
}
}
});
};

retry();
}

ts.adInit = function () {
var slots = ts.adSlots || [];
var bids = ts.bids || {};
Expand Down Expand Up @@ -476,6 +730,14 @@
}
var actualDivId = el.id;
var b = bids[slot.id] || {};
var tsClaim = claimFirstImpressionForTrustedServer(el);
if (!tsClaim) {
var currentClaim = firstImpressionClaim(el);
if (currentClaim && currentClaim.owner === "publisher") {
scheduleFirstImpressionFallback(slot, b, el, generation);
}
return;
}

var existingSlots = googletag.pubads().getSlots();
var s =
Expand All @@ -493,7 +755,10 @@
actualDivId,
);
});
if (!s) return;
if (!s) {
releaseTrustedServerFirstImpressionClaim(el, tsClaim);
return;
}
s.addService(googletag.pubads());
tsOwned = true;
ts.gptSlotHandoffs = ts.gptSlotHandoffs || {};
Expand All @@ -508,20 +773,11 @@
};
}

Object.entries(slot.targeting || {}).forEach(function (e) {
s.setTargeting(e[0], e[1]);
});
[
"hb_pb",
"hb_bidder",
"hb_adid",
"hb_cache_host",
"hb_cache_path",
].forEach(function (k) {
if (b[k]) s.setTargeting(k, b[k]);
var targeting = bootstrapTargeting(slot, b);
Object.entries(targeting).forEach(function (entry) {
s.setTargeting(entry[0], entry[1]);
});
// Keep in sync with TS_INITIAL_TARGETING_KEY in index.ts
s.setTargeting("ts_initial", "1");
tsClaim.targeting = targeting;
// Map the resolved inner div to the slot ID. This bootstrap fires no
// beacons and registers no slotRenderEnded listener; the map is consumed
// by the bundle's render bridge (index.ts) once it loads.
Expand All @@ -540,7 +796,9 @@
});
ts.prevGptSlots = newSlots;
ts.divToSlotId = divToSlotId;
if (!ts.servicesEnabled) {
var hasRenderableWork =
slotsToDisplay.length > 0 || slotsToRefresh.length > 0;
if (!ts.servicesEnabled && hasRenderableWork) {
googletag.pubads().enableSingleRequest();
googletag.enableServices();
ts.servicesEnabled = true;
Expand Down
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