116 lines
3.7 KiB
Dart
116 lines
3.7 KiB
Dart
/*
|
|
* Copyright (c) 2024-2026 Fabian Freund.
|
|
*
|
|
* This file is part of WebLibre
|
|
* (see https://weblibre.eu).
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Affero General Public License as
|
|
* published by the Free Software Foundation, either version 3 of the
|
|
* License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU Affero General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Affero General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
import 'dart:convert';
|
|
import 'dart:typed_data';
|
|
|
|
import 'package:sqlite3/common.dart';
|
|
import 'package:weblibre/utils/url_canonical.dart';
|
|
import 'package:xxh3/xxh3.dart';
|
|
|
|
/// Bytes 0x1F (Unit Separator) between hashed parts. Prevents collisions
|
|
/// where `(a, b)` and `(ab, '')` would otherwise hash to the same value.
|
|
const _hashSeparator = 0x1F;
|
|
|
|
/// xxh3-64 over the trigger-relevant content fields.
|
|
///
|
|
/// Inputs may be any nullable mix of TEXT columns. The hash is stable for
|
|
/// the same content + ordering, and `IS NOT` comparison on the resulting
|
|
/// INTEGER is enough to gate downstream FTS / fan-out triggers.
|
|
int? _contentHash(List<Object?> args) {
|
|
if (args.every((a) => a == null)) return null;
|
|
final builder = BytesBuilder(copy: false);
|
|
for (final part in args) {
|
|
if (part is String) {
|
|
builder.add(utf8.encode(part));
|
|
}
|
|
builder.addByte(_hashSeparator);
|
|
}
|
|
// xxh3 returns an unsigned 64-bit value, but Dart ints on 64-bit platforms
|
|
// are signed 64-bit. The bit pattern round-trips fine through SQLite as
|
|
// INTEGER; we just lose the unsigned interpretation, which doesn't matter
|
|
// for `IS NOT` comparisons.
|
|
return xxh3(builder.toBytes());
|
|
}
|
|
|
|
String? _urlCanonical(List<Object?> args) {
|
|
final url = args.first as String?;
|
|
if (url == null) return null;
|
|
return canonicalizeUrl(url)?.canonical;
|
|
}
|
|
|
|
String? _urlHost(List<Object?> args) {
|
|
final url = args.first as String?;
|
|
if (url == null) return null;
|
|
return canonicalizeUrl(url)?.host;
|
|
}
|
|
|
|
String? _urlPath(List<Object?> args) {
|
|
final url = args.first as String?;
|
|
if (url == null) return null;
|
|
return canonicalizeUrl(url)?.path;
|
|
}
|
|
|
|
/// Boolean-as-INTEGER (0/1) for use in trigger `WHEN` clauses.
|
|
int _urlIndexable(List<Object?> args) {
|
|
final url = args.first as String?;
|
|
if (url == null) return 0;
|
|
return isUrlIndexable(url) ? 1 : 0;
|
|
}
|
|
|
|
void registerUrlFunctions(CommonDatabase database) {
|
|
database.createFunction(
|
|
functionName: 'url_canonical',
|
|
argumentCount: const AllowedArgumentCount(1),
|
|
deterministic: true,
|
|
directOnly: false,
|
|
function: _urlCanonical,
|
|
);
|
|
database.createFunction(
|
|
functionName: 'url_host',
|
|
argumentCount: const AllowedArgumentCount(1),
|
|
deterministic: true,
|
|
directOnly: false,
|
|
function: _urlHost,
|
|
);
|
|
database.createFunction(
|
|
functionName: 'url_path',
|
|
argumentCount: const AllowedArgumentCount(1),
|
|
deterministic: true,
|
|
directOnly: false,
|
|
function: _urlPath,
|
|
);
|
|
database.createFunction(
|
|
functionName: 'url_indexable',
|
|
argumentCount: const AllowedArgumentCount(1),
|
|
deterministic: true,
|
|
directOnly: false,
|
|
function: _urlIndexable,
|
|
);
|
|
// 3-arg form covers the (title, extracted_plain, full_plain) trigger guard.
|
|
// Marked deterministic so generated columns can use it.
|
|
database.createFunction(
|
|
functionName: 'generate_content_hash',
|
|
argumentCount: const AllowedArgumentCount(3),
|
|
deterministic: true,
|
|
directOnly: false,
|
|
function: _contentHash,
|
|
);
|
|
}
|