Files
moxxy/lib/service/files.dart

362 lines
10 KiB
Dart

import 'dart:convert';
import 'dart:io';
import 'dart:ui';
import 'package:get_it/get_it.dart';
import 'package:logging/logging.dart';
import 'package:moxplatform/moxplatform.dart';
import 'package:moxxmpp/moxxmpp.dart';
import 'package:moxxyv2/service/cryptography/cryptography.dart';
import 'package:moxxyv2/service/database/constants.dart';
import 'package:moxxyv2/service/database/database.dart';
import 'package:moxxyv2/service/httpfiletransfer/location.dart';
import 'package:moxxyv2/service/not_specified.dart';
import 'package:moxxyv2/shared/models/file_metadata.dart';
import 'package:moxxyv2/shared/thumbnails/helpers.dart';
import 'package:path/path.dart' as path;
import 'package:sqflite_common/sql.dart';
/// A class for returning whether a file metadata element was just created or retrieved.
class FileMetadataWrapper {
FileMetadataWrapper(
this.fileMetadata,
this.retrieved,
);
/// The file metadata.
FileMetadata fileMetadata;
/// Indicates whether the file metadata already exists (true) or
/// if it has been created (false).
bool retrieved;
}
/// Returns the strongest hash from [map], if [map] is not null. If no known hash is found
/// or [map] is null, returns null.
String? getStrongestHashFromMap(Map<HashFunction, String>? map) {
if (map == null) {
return null;
}
return map[HashFunction.blake2b512] ??
map[HashFunction.blake2b256] ??
map[HashFunction.sha3_512] ??
map[HashFunction.sha3_256] ??
map[HashFunction.sha512] ??
map[HashFunction.sha256];
}
/// Calculates the path for a given file with filename [filename] and the optional
/// plaintext hashes [hashes]. If the base directory for the file does not exist, then it
/// will be created.
Future<String> computeCachedPathForFile(
String filename,
Map<HashFunction, String>? hashes,
) async {
final basePath = path.join(
await MoxplatformPlugin.platform.getPersistentDataPath(),
'media',
);
final baseDir = Directory(basePath);
if (!baseDir.existsSync()) {
await baseDir.create(recursive: true);
}
// Keep the extension of the file. Otherwise Android will be really confused
// as to what it should open the file with.
final ext = path.extension(filename);
final hash = getStrongestHashFromMap(hashes)?.replaceAll('/', '_');
return path.join(
basePath,
hash != null
// NOTE: [ext] already includes a leading "."
? '$hash$ext'
: '$filename.${DateTime.now().millisecondsSinceEpoch}.$ext',
);
}
class FilesService {
// Logging.
final Logger _log = Logger('FilesService');
Future<void> createMetadataHashEntries(
Map<HashFunction, String> plaintextHashes,
String metadataId,
) async {
final db = GetIt.I.get<DatabaseService>().database;
for (final hash in plaintextHashes.entries) {
await db.insert(
fileMetadataHashesTable,
{
'algorithm': hash.key.toName(),
'value': hash.value,
'id': metadataId,
},
// TODO(Unknown): I would like to get rid of this. In events.dart, when processing
// a request to manually download a file, we should check if we already
// have hash pointers for a file metadata item.
conflictAlgorithm: ConflictAlgorithm.ignore,
);
}
}
Future<FileMetadata?> getFileMetadataFromFile(FileMetadata metadata) async {
final hash = metadata.plaintextHashes?[HashFunction.sha256] ??
await GetIt.I
.get<CryptographyService>()
.hashFile(metadata.path!, HashFunction.sha256);
final fm = await getFileMetadataFromHash({
HashFunction.sha256: hash,
});
if (fm != null) {
return fm;
}
final result = await addFileMetadataFromData(
metadata.copyWith(
plaintextHashes: {
...metadata.plaintextHashes ?? {},
HashFunction.sha256: hash,
},
),
);
await createMetadataHashEntries(result.plaintextHashes!, result.id);
return result;
}
Future<FileMetadata?> getFileMetadataFromHash(
Map<HashFunction, String>? plaintextHashes,
) async {
if (plaintextHashes?.isEmpty ?? true) {
return null;
}
final db = GetIt.I.get<DatabaseService>().database;
final values = List<String>.empty(growable: true);
final query = plaintextHashes!.entries.map((entry) {
values
..add(entry.key.toName())
..add(entry.value);
return '(algorithm = ? AND value = ?)';
}).join(' OR ');
final hashes = await db.query(
fileMetadataHashesTable,
where: query,
whereArgs: values,
limit: 1,
);
if (hashes.isEmpty) {
return null;
}
final result = await db.query(
fileMetadataTable,
where: 'id = ?',
whereArgs: [hashes[0]['id']! as String],
limit: 1,
);
if (result.isEmpty) {
return null;
}
return FileMetadata.fromDatabaseJson(result[0]);
}
/// Create a FileMetadata entry if we do not know the plaintext hashes described in
/// [location].
/// If we know of at least one hash, return that FileMetadata element.
///
/// If [createHashPointers] is true and we have to create a new FileMetadata element,
/// then also create the hash pointers, if plaintext hashes are specified. If no
/// plaintext hashes are specified or [createHashPointers] is false, no pointers will be
/// created.
Future<FileMetadataWrapper> createFileMetadataIfRequired(
MediaFileLocation location,
String? mimeType,
int? size,
Size? dimensions,
String? thubnailType,
String? thumbnailData, {
bool createHashPointers = true,
String? path,
}) async {
if (location.plaintextHashes?.isNotEmpty ?? false) {
final result = await getFileMetadataFromHash(location.plaintextHashes);
if (result != null) {
_log.finest('Not creating new metadata as we found the hash');
return FileMetadataWrapper(
result,
true,
);
}
}
final db = GetIt.I.get<DatabaseService>().database;
final fm = FileMetadata(
getStrongestHashFromMap(location.plaintextHashes) ??
DateTime.now().millisecondsSinceEpoch.toString(),
path,
location.urls,
mimeType,
size,
thubnailType,
thumbnailData,
dimensions?.width.toInt(),
dimensions?.height.toInt(),
location.plaintextHashes,
location.key != null ? base64Encode(location.key!) : null,
location.iv != null ? base64Encode(location.iv!) : null,
location.encryptionScheme,
location.ciphertextHashes,
location.filename,
);
await db.insert(fileMetadataTable, fm.toDatabaseJson());
if ((location.plaintextHashes?.isNotEmpty ?? false) && createHashPointers) {
await createMetadataHashEntries(
location.plaintextHashes!,
fm.id,
);
}
return FileMetadataWrapper(
fm,
false,
);
}
Future<void> removeFileMetadata(String id) async {
await GetIt.I.get<DatabaseService>().database.delete(
fileMetadataTable,
where: 'id = ?',
whereArgs: [id],
);
}
Future<FileMetadata> updateFileMetadata(
String id, {
Object? path = notSpecified,
int? size,
String? encryptionScheme,
String? encryptionKey,
String? encryptionIv,
List<String>? sourceUrls,
int? width,
int? height,
String? mimeType,
Map<String, String>? plaintextHashes,
Map<String, String>? ciphertextHashes,
}) async {
final db = GetIt.I.get<DatabaseService>().database;
final m = <String, dynamic>{};
if (path != notSpecified) {
m['path'] = path as String?;
}
if (encryptionScheme != null) {
m['encryptionScheme'] = encryptionScheme;
}
if (size != null) {
m['size'] = size;
}
if (encryptionKey != null) {
m['encryptionKey'] = encryptionKey;
}
if (encryptionIv != null) {
m['encryptionIv'] = encryptionIv;
}
if (sourceUrls != null) {
m['sourceUrl'] = jsonEncode(sourceUrls);
}
if (width != null) {
m['width'] = width;
}
if (height != null) {
m['height'] = height;
}
if (mimeType != null) {
m['mimeType'] = mimeType;
}
if (plaintextHashes != null) {
m['plaintextHashes'] = jsonEncode(plaintextHashes);
}
if (ciphertextHashes != null) {
m['cipherTextHashes'] = jsonEncode(ciphertextHashes);
}
final result = await db.updateAndReturn(
fileMetadataTable,
m,
where: 'id = ?',
whereArgs: [id],
);
return FileMetadata.fromDatabaseJson(result);
}
/// Removes the file metadata described by [metadata] if it is referenced by exactly 0
/// messages and no stickers use this file. If the file is referenced by > 1 messages
/// or a sticker, does nothing.
Future<void> removeFileIfNotReferenced(FileMetadata metadata) async {
final db = GetIt.I.get<DatabaseService>().database;
final messagesCount = await db.count(
messagesTable,
'file_metadata_id = ?',
[metadata.id],
);
final stickersCount = await db.count(
stickersTable,
'file_metadata_id = ?',
[metadata.id],
);
if (messagesCount == 0 && stickersCount == 0) {
_log.finest(
'Removing file metadata as no stickers and no messages reference it',
);
await removeFileMetadata(metadata.id);
// Only remove the file if we have a path
if (metadata.path != null) {
try {
await File(metadata.path!).delete();
} catch (ex) {
_log.warning('Failed to remove file ${metadata.path!}: $ex');
}
if (metadata.mimeType?.startsWith('video/') ?? false) {
final thumbnailPath = await getVideoThumbnailPath(metadata.path!);
final thumbnailFile = File(thumbnailPath);
if (thumbnailFile.existsSync()) {
try {
await thumbnailFile.delete();
} catch (ex) {
_log.warning(
'Failed to remove thumbnail file $thumbnailPath: $ex',
);
}
}
}
} else {
_log.info('Not removing file as there is no path associated with it');
}
} else {
_log.info(
'Not removing file as $messagesCount messages and $stickersCount stickers reference this file',
);
}
}
Future<FileMetadata> addFileMetadataFromData(
FileMetadata metadata,
) async {
final result =
await GetIt.I.get<DatabaseService>().database.insertAndReturn(
fileMetadataTable,
metadata.toDatabaseJson(),
);
return FileMetadata.fromDatabaseJson(result);
}
}