feat(moderation): refactor word analysis caching to text analysis caching with improved context handling

2026-05-31 20:33:27 +07:00
parent 7e58741b5c
commit d63e34d259
5 changed files with 300 additions and 340 deletions
@@ -0,0 +1,151 @@
+import { executeAll, executeGet } from "../database/drizzle.js";
+import { createChildLogger } from "../logger.js";
+
+const logger = createChildLogger("text-cache-store");
+
+export interface TextCacheEntry {
+  text: string;
+  flags: string[];
+  source: "local" | "nvidia" | "primary_ai" | "groq";
+  analyzed_at: number;
+  expires_at: number;
+  hit_count: number;
+}
+
+/**
+ * Lookup cached analysis result for a normalized text string.
+ * Returns null if not found or expired.
+ */
+export async function getCachedText(
+  text: string,
+): Promise<TextCacheEntry | null> {
+  try {
+    const row = await executeGet(
+      `SELECT text, flags, source, analyzed_at, expires_at, hit_count
+       FROM text_analysis_cache
+       WHERE text = $1 AND expires_at > $2`,
+      [text, Date.now()],
+    );
+
+    if (!row) return null;
+
+    return {
+      text: row.text,
+      flags: JSON.parse(row.flags),
+      source: row.source,
+      analyzed_at: row.analyzed_at,
+      expires_at: row.expires_at,
+      hit_count: row.hit_count,
+    };
+  } catch (error) {
+    logger.error(
+      { error: error instanceof Error ? error.message : String(error) },
+      "Failed to get cached text",
+    );
+    return null;
+  }
+}
+
+/**
+ * Insert or update a text analysis cache entry.
+ */
+export async function upsertCachedText(
+  text: string,
+  flags: string[],
+  source: "local" | "nvidia" | "primary_ai" | "groq",
+  expiresAt: number,
+): Promise<void> {
+  const now = Date.now();
+
+  try {
+    await executeAll(
+      `INSERT INTO text_analysis_cache (text, flags, source, analyzed_at, expires_at, hit_count)
+       VALUES ($1, $2, $3, $4, $5, 0)
+       ON CONFLICT (text) DO UPDATE SET
+         flags = EXCLUDED.flags,
+         source = EXCLUDED.source,
+         analyzed_at = EXCLUDED.analyzed_at,
+         expires_at = EXCLUDED.expires_at`,
+      [text, JSON.stringify(flags), source, now, expiresAt],
+    );
+  } catch (error) {
+    logger.error(
+      { error: error instanceof Error ? error.message : String(error) },
+      "Failed to upsert cached text",
+    );
+  }
+}
+
+/**
+ * Increment hit count for a cached text entry (called on cache hit).
+ */
+export async function incrementTextCacheHit(text: string): Promise<void> {
+  try {
+    await executeAll(
+      `UPDATE text_analysis_cache SET hit_count = hit_count + 1 WHERE text = $1`,
+      [text],
+    );
+  } catch (error) {
+    // Silent fail — this is just a counter, not critical
+  }
+}
+
+/**
+ * Delete expired cache entries. Run periodically to keep the table clean.
+ */
+export async function pruneExpiredTexts(): Promise<number> {
+  try {
+    const result = await executeAll(
+      `DELETE FROM text_analysis_cache WHERE expires_at < $1`,
+      [Date.now()],
+    );
+    return (result as any).rowCount ?? 0;
+  } catch (error) {
+    logger.error(
+      { error: error instanceof Error ? error.message : String(error) },
+      "Failed to prune expired texts",
+    );
+    return 0;
+  }
+}
+
+/**
+ * Get cache statistics for observability.
+ */
+export async function getTextCacheStats(): Promise<{
+  total: number;
+  expired: number;
+  bySource: Record<string, number>;
+}> {
+  try {
+    const now = Date.now();
+
+    const [totalRow, expiredRow, sourceRows] = await Promise.all([
+      executeAll(`SELECT count(*) as cnt FROM text_analysis_cache`),
+      executeAll(
+        `SELECT count(*) as cnt FROM text_analysis_cache WHERE expires_at < $1`,
+        [now],
+      ),
+      executeAll(
+        `SELECT source, count(*) as cnt FROM text_analysis_cache GROUP BY source`,
+      ),
+    ]);
+
+    const bySource: Record<string, number> = {};
+    for (const row of sourceRows) {
+      bySource[row.source] = row.cnt;
+    }
+
+    return {
+      total: totalRow[0]?.cnt ?? 0,
+      expired: expiredRow[0]?.cnt ?? 0,
+      bySource,
+    };
+  } catch (error) {
+    logger.error(
+      { error: error instanceof Error ? error.message : String(error) },
+      "Failed to get text cache stats",
+    );
+    return { total: 0, expired: 0, bySource: {} };
+  }
+}