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src/patchCandidateWorker.js

@@ -0,0 +1,64 @@
+import { generateMap } from "./mapPipeline.js";
+import { collectTransferableBuffers } from "./transferUtils.js";
+import { compactRawPatchCandidate, summarizeRawPatchCandidate } from "./rawPatchCandidate.js";
+
+function scopeTaskProgress(event = {}, taskId) {
+  const scoped = { ...event };
+  if (event?.workUnitId != null && String(event.workUnitId).length > 0) {
+    scoped.workUnitId = `${taskId}/${String(event.workUnitId)}`;
+  }
+  return scoped;
+}
+
+if (typeof self !== "undefined") {
+  self.onmessage = (event) => {
+    const message = event.data || {};
+    if (message.type !== "generate-raw-patch-candidate") return;
+    const taskId = String(message.taskId || `raw-${message.id || 0}`);
+    const startedAt = typeof performance !== "undefined" && performance.now ? performance.now() : Date.now();
+    try {
+      let candidate = generateMap(Number(message.seed) >>> 0, {
+        ...(message.mapOptions || {}),
+        // A boolean sentinel is sufficient: mapPipeline only records whether a
+        // boundary world exists. Actual seam/quality work remains in the parent
+        // patch worker after this raw candidate has been transferred back.
+        boundaryWorld: true,
+        onProgress: (progress) => {
+          self.postMessage({
+            type: "raw-patch-candidate-progress",
+            id: message.id,
+            taskId,
+            progress: scopeTaskProgress(progress, taskId),
+          });
+        },
+      });
+      const elapsedMs = (typeof performance !== "undefined" && performance.now ? performance.now() : Date.now()) - startedAt;
+      // Transfer only the roots consumed by mapPatch. Full-map geography/debug
+      // graphs can exceed the actual patch payload and are never consulted by
+      // candidate merge/quality logic. Dropping them before structured clone
+      // creates a hard cross-worker memory bound for large tiled operations.
+      candidate = compactRawPatchCandidate(candidate);
+      const transferSummary = summarizeRawPatchCandidate(candidate);
+      const transferables = [...collectTransferableBuffers(candidate)];
+      self.postMessage({
+        type: "raw-patch-candidate-result",
+        id: message.id,
+        taskId,
+        ok: true,
+        elapsedMs,
+        transferSummary,
+        candidate,
+      }, transferables);
+    } catch (error) {
+      self.postMessage({
+        type: "raw-patch-candidate-result",
+        id: message.id,
+        taskId,
+        ok: false,
+        code: error?.code || "raw-patch-candidate-error",
+        error: error?.message || String(error),
+        stack: error?.stack || "",
+      });
+    }
+  };
+}