gongxiangp2/prisma/migrations/20261009_material_purge_reference_indexes/migration.sql

BEGIN;

-- 只建立引用检索索引，不改动业务记录。索引由 PostgreSQL 随每次写入维护，
-- 因而覆盖 ORM、历史导入及直接 SQL 写入，不依赖应用层双写或定时回填。
CREATE FUNCTION purge_decode_reference(value text) RETURNS text
LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL UNSAFE AS $$
DECLARE result bytea := ''::bytea; position integer := 1; piece text;
BEGIN
  IF strpos(value, '%') = 0 THEN RETURN value; END IF;
  WHILE position <= length(value) LOOP
    piece := substr(value, position, 1);
    IF piece = '%' THEN
      piece := substr(value, position + 1, 2);
      IF piece !~ '^[0-9a-fA-F]{2}$' THEN RETURN value; END IF;
      result := result || decode(piece, 'hex'); position := position + 3;
    ELSE
      result := result || convert_to(piece, 'UTF8'); position := position + 1;
    END IF;
  END LOOP;
  RETURN convert_from(result, 'UTF8');
EXCEPTION WHEN character_not_in_repertoire OR untranslatable_character THEN RETURN value;
END;
$$;

CREATE FUNCTION purge_json_reference_strings(value jsonb) RETURNS text[]
LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL UNSAFE AS $$
DECLARE result text[] := '{}'; child jsonb;
BEGIN
  CASE jsonb_typeof(value)
    WHEN 'string' THEN RETURN ARRAY[value #>> '{}'];
    WHEN 'array' THEN
      FOR child IN SELECT jsonb_array_elements(value) LOOP
        result := result || purge_json_reference_strings(child);
      END LOOP;
    WHEN 'object' THEN
      FOR child IN SELECT v FROM jsonb_each(value) AS entry(k, v) LOOP
        result := result || purge_json_reference_strings(child);
      END LOOP;
    ELSE NULL;
  END CASE;
  RETURN result;
END;
$$;

-- 哈希仅用于索引候选匹配，最终删除授权仍使用应用的完整 storage/bucket/key。
-- 哈希冲突只会增加候选，不会授权删除；内嵌 data:image 不进入文件索引。
CREATE FUNCTION purge_reference_keys(sources text[], derive_white_background boolean) RETURNS text[]
LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL UNSAFE AS $$
DECLARE
  result text[] := '{}'; source text; value text; local_source text; decoded text; derived text;
  segments text[]; tail text[]; wb integer; round integer; is_http boolean;
  whitespace text := U&'\0009\000A\000B\000C\000D\0020\00A0\1680\2000\2001\2002\2003\2004\2005\2006\2007\2008\2009\200A\2028\2029\202F\205F\3000\FEFF';
BEGIN
  FOREACH source IN ARRAY sources LOOP
    value := btrim(source, whitespace);
    IF value IS NULL OR value = '' OR value LIKE 'data:image/%' THEN CONTINUE; END IF;
    is_http := value ~* '^https?://';
    value := replace(value, chr(92), '/');
    IF is_http THEN
      -- URL 的点段及内嵌制表/换行由 WHATWG URL 处理。保留稀少的这类候选，
      -- 不在 SQL 中另写一套 URL 授权规则；常规地址及编码地址走精确索引。
      IF value ~ E'[\\t\\r\\n]' OR value ~* '/(\.|%2e)' THEN
        result := array_append(result, 'url:resolve');
      END IF;
      value := regexp_replace(value, '[?#].*$', '');
      value := regexp_replace(value, '^https?://[^/]*', '', 'i');
    END IF;
    IF NOT is_http THEN
      value := regexp_replace(value, '/+', '/', 'g');
      WHILE value ~ '(^|/)\.(\/|$)' LOOP
        value := regexp_replace(value, '(^|/)\.(\/|$)', '\1', 'g');
      END LOOP;
    END IF;
    local_source := value;
    IF value ~ '[^\x01-\x7f]' THEN result := array_append(result, 'windows:unicode'); END IF;
    FOR round IN 0..6 LOOP
      IF is_http THEN value := regexp_replace(value, '^/+', '/'); END IF;
      result := result || ARRAY['path:' || md5(value),
        'ascii:' || md5(translate(value, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', 'abcdefghijklmnopqrstuvwxyz'))];
      decoded := purge_decode_reference(value);
      EXIT WHEN decoded = value;
      value := decoded;
    END LOOP;
    IF derive_white_background AND NOT is_http THEN
      segments := array_remove(string_to_array(local_source, '/'), '');
      wb := array_position(segments, 'white-background');
      IF wb >= 3 AND array_length(segments, 1) >= wb + 2 THEN
        tail := segments[wb + 2:array_length(segments, 1)];
        IF tail[1] = 'preview' THEN tail := tail[2:array_length(tail, 1)]; END IF;
        IF cardinality(tail) > 0 THEN
          derived := 'white-background/' || segments[wb - 1] || '/' || segments[wb + 1] || '/' || array_to_string(tail, '/');
          IF derived ~ E'[\\t\\r\\n]' OR derived ~* '/(\.|%2e)' THEN
            result := array_append(result, 'url:resolve');
          END IF;
          -- 派生地址会经过 URL 解析；原始 ?/# 是查询/片段，编码形式仍是文件名。
          derived := regexp_replace(derived, '[?#].*$', '');
          FOR round IN 0..6 LOOP
            result := array_append(result, 'derived:' || md5(derived));
            decoded := purge_decode_reference(derived);
            EXIT WHEN decoded = derived;
            derived := decoded;
          END LOOP;
        END IF;
      END IF;
    END IF;
  END LOOP;
  RETURN ARRAY(SELECT DISTINCT token FROM unnest(result) token);
END;
$$;

CREATE INDEX materials_purge_references_idx ON materials USING gin
  (purge_reference_keys(ARRAY["previewUrl", "zipFilePath", "videoSourceUrl", "videoPreview540Url", "videoPreviewClipUrl", "videoCoverUrl"] || "displayImages", false));
CREATE INDEX material_assets_purge_references_idx ON material_assets USING gin
  (purge_reference_keys(ARRAY[file_url], true));
CREATE INDEX material_skus_purge_references_idx ON material_skus USING gin
  (purge_reference_keys(ARRAY[file_path, preview_url], false));
CREATE INDEX brand_knowledge_purge_references_idx ON brand_knowledge USING gin
  (purge_reference_keys(ARRAY[file_path, preview_image_path] || preview_image_slices, false));
CREATE INDEX system_settings_purge_references_idx ON system_settings USING gin
  (purge_reference_keys(ARRAY["headerLogoUrl", "loginLogoUrl"], false));
CREATE INDEX performance_work_items_purge_references_idx ON performance_survey_work_items USING gin
  (purge_reference_keys(purge_json_reference_strings(image_urls), false));
CREATE INDEX work_review_versions_purge_references_idx ON work_review_versions USING gin
  (purge_reference_keys(purge_json_reference_strings(image_urls), false));
CREATE INDEX package_upload_jobs_purge_references_idx ON product_package_upload_jobs USING gin
  (purge_reference_keys(purge_json_reference_strings(assets), false)) WHERE status IN ('queued', 'processing');
CREATE INDEX task_detail_changes_purge_references_idx ON task_detail_change_requests USING gin
  (purge_reference_keys(purge_json_reference_strings(operations), false)) WHERE status NOT IN ('applied', 'rejected', 'expired', 'cancelled');

ANALYZE materials;
ANALYZE material_assets;
ANALYZE material_skus;
ANALYZE brand_knowledge;
ANALYZE system_settings;
ANALYZE performance_survey_work_items;
ANALYZE work_review_versions;
ANALYZE product_package_upload_jobs;
ANALYZE task_detail_change_requests;
COMMIT;