nandi.uk
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fix: preserve summaries + strata across cache rebuilds
On rebuild, compute the new lexmin-hash ID for each old island
and carry forward its summary and strata data to the new row.
👾 Generated with [Letta Code](https://letta.com)
Co-Authored-By: Letta Code <noreply@letta.com>
author
nandi
co-author
Letta Code
date
(May 13, 2026, 5:30 AM UTC)
commit
221079b7
221079b7bdeb192b902928e3077c38dd3c87300f
parent
8f6c8a8d
8f6c8a8db1a4b49ab2762fa3531986f29ad3b71a
+27
-12
+27
-12
src/worker.ts
+27
-12
src/worker.ts
···
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});
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}
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-
// Preserve existing summaries across rebuild
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+
// Preserve existing summaries + strata across rebuild
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// Match by lexmin vertex: since the ID is sha256(lexmin)[:16], we can
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// match old rows to new islands by computing the new ID from the old data.
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const existing = await db
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.prepare("SELECT id, summary FROM island_cache")
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.all<{ id: string; summary: string | null }>();
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const summaries = new Map<string, string>();
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.prepare("SELECT id, data, summary, strata FROM island_cache")
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.all<{ id: string; data: string; summary: string | null; strata: string | null }>();
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+
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const preserved = new Map<string, { summary: string | null; strata: string | null }>();
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for (const row of existing.results || []) {
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if (row.summary) summaries.set(row.id, row.summary);
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try {
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const oldIsland = JSON.parse(row.data);
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const oldLexmin = oldIsland.vertices?.sort()?.[0];
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if (!oldLexmin) continue;
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// Compute the new ID for this old island
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const hash = await crypto.subtle.digest("SHA-256", new TextEncoder().encode(oldLexmin));
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const newId = Array.from(new Uint8Array(hash)).map(b => b.toString(16).padStart(2, "0")).join("").slice(0, 16);
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if (row.summary || row.strata) {
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preserved.set(newId, { summary: row.summary, strata: row.strata });
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}
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} catch {}
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}
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const now = Date.now() * 1000;
···
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// Clear old cache and write new
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await db.prepare("DELETE FROM island_cache").run();
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const stmts = enriched.map(island =>
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db
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const stmts = enriched.map(island => {
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const saved = preserved.get(island.id);
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return db
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.prepare(
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`INSERT INTO island_cache (id, vertex_count, edge_count, data, summary, updated_at)
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VALUES (?, ?, ?, ?, ?, ?)`,
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`INSERT INTO island_cache (id, vertex_count, edge_count, data, summary, strata, updated_at)
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VALUES (?, ?, ?, ?, ?, ?, ?)`,
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)
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.bind(
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island.id,
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island.vertices.length,
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island.edges.length,
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JSON.stringify(island),
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summaries.get(island.id) || null,
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saved?.summary || null,
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saved?.strata || null,
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now,
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),
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);
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);
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});
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// D1 supports batched statements
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if (stmts.length > 0) {