platform/packages/static/lib/src/virtual_directory.dart
thomashii@dukefirehawk.com 7d8677e308 Fixed static analysis warnings
2022-08-17 11:25:45 +08:00

398 lines
13 KiB
Dart

import 'dart:async';
import 'package:angel3_framework/angel3_framework.dart';
import 'package:file/file.dart';
import 'package:http_parser/http_parser.dart';
import 'package:path/path.dart' as p;
import 'package:logging/logging.dart';
import 'package:belatuk_range_header/belatuk_range_header.dart';
final RegExp _param = RegExp(r':([A-Za-z0-9_]+)(\((.+)\))?');
final RegExp _straySlashes = RegExp(r'(^/+)|(/+$)');
String _pathify(String path) {
var p = path.replaceAll(_straySlashes, '');
var replace = {};
for (Match match in _param.allMatches(p)) {
if (match[3] != null) replace[match[0]] = ':${match[1]}';
}
replace.forEach((k, v) {
if (k is String && v is String) {
p = p.replaceAll(k, v);
}
});
return p;
}
/// A static server plug-in.
class VirtualDirectory {
final _log = Logger('VirtualDirectory');
late String _prefix;
late Directory _source;
/// The directory to serve files from.
Directory get source => _source;
/// An optional callback to run before serving files.
final Function(File file, RequestContext req, ResponseContext res)? callback;
final Angel app;
final FileSystem fileSystem;
/// Filenames to be resolved within directories as indices.
final Iterable<String> indexFileNames;
/// An optional public path to map requests to.
final String publicPath;
/// If `true` (default: `false`), then if a directory does not contain any of the specific [indexFileNames], a default directory listing will be served.
final bool allowDirectoryListing;
/// If `true` (default: `true`), then files will be opened as streams and piped into the request.
///
/// If not, the response buffer will be used instead.
final bool useBuffer;
VirtualDirectory(this.app, this.fileSystem,
{Directory? source,
this.indexFileNames = const ['index.html'],
this.publicPath = '/',
this.callback,
this.allowDirectoryListing = false,
this.useBuffer = false}) {
_prefix = publicPath.replaceAll(_straySlashes, '');
if (source != null) {
_source = source;
} else {
var dirPath = app.environment.isProduction ? './build/web' : './web';
_source = fileSystem.directory(dirPath);
}
}
/// Responds to incoming HTTP requests.
Future<bool> handleRequest(RequestContext req, ResponseContext res) {
if (req.method != 'GET' && req.method != 'HEAD') {
return Future<bool>.value(true);
}
var path = req.uri!.path.replaceAll(_straySlashes, '');
if (_prefix.isNotEmpty == true && !path.startsWith(_prefix)) {
return Future<bool>.value(true);
}
return servePath(path, req, res);
}
/// A handler that serves the file at the given path, unless the user has requested that path.
///
/// You can also limit this functionality to specific values of the `Accept` header, ex. `text/html`.
/// If [accepts] is `null`, OR at least one of the content types in [accepts] is present,
/// the view will be served.
RequestHandler pushState(String path, {Iterable? accepts}) {
var vPath = path.replaceAll(_straySlashes, '');
if (_prefix.isNotEmpty == true) vPath = '$_prefix/$vPath';
return (RequestContext req, ResponseContext res) {
var path = req.path.replaceAll(_straySlashes, '');
if (path == vPath) return Future<bool>.value(true);
if (accepts?.isNotEmpty == true) {
if (!accepts!.any((x) => req.accepts(x, strict: true))) {
return Future<bool>.value(true);
}
}
return servePath(vPath, req, res);
};
}
/// Writes the file at the given virtual [path] to a response.
Future<bool> servePath(
String path, RequestContext req, ResponseContext res) async {
if (_prefix.isNotEmpty) {
// Only replace the *first* incidence
// Resolve: https://github.com/angel-dart/angel/issues/41
path = path.replaceFirst(RegExp('^${_pathify(_prefix)}'), '');
}
if (path.isEmpty) path = '.';
path = path.replaceAll(_straySlashes, '');
var absolute = source.absolute.uri.resolve(path).toFilePath();
var parent = source.absolute.uri.toFilePath();
if (!p.isWithin(parent, absolute) && !p.equals(parent, absolute)) {
return true;
}
// Update to the correct file separator based on file system
if (absolute.contains('\\') && fileSystem.path.separator == '/') {
absolute = absolute.replaceAll('\\', '/');
_log.warning(
'Incompatible file system type is used. Changed file separator from "\\" to "/".');
} else if (absolute.contains('/') && fileSystem.path.separator == '\\') {
absolute = absolute.replaceAll('/', '\\');
_log.warning(
'Incompatible file system type. Changed file separator from "/" to "\\".');
}
var stat = await fileSystem.stat(absolute);
return await serveStat(absolute, path, stat, req, res);
}
/// Writes the file at the path given by the [stat] to a response.
Future<bool> serveStat(String absolute, String relative, FileStat stat,
RequestContext req, ResponseContext res) async {
if (stat.type == FileSystemEntityType.directory) {
return await serveDirectory(
fileSystem.directory(absolute), relative, stat, req, res);
} else if (stat.type == FileSystemEntityType.file) {
return await serveFile(fileSystem.file(absolute), stat, req, res);
} else if (stat.type == FileSystemEntityType.link) {
var link = fileSystem.link(absolute);
return await servePath(await link.resolveSymbolicLinks(), req, res);
} else {
return true;
}
}
/// Serves the index file of a [directory], if it exists.
Future<bool> serveDirectory(Directory directory, String relative,
FileStat stat, RequestContext req, ResponseContext res) async {
for (var indexFileName in indexFileNames) {
final index =
fileSystem.file(directory.absolute.uri.resolve(indexFileName));
if (await index.exists()) {
return await serveFile(index, stat, req, res);
}
}
if (allowDirectoryListing == true) {
res.contentType = MediaType('text', 'html');
res
..write('<!DOCTYPE html>')
..write('<html>')
..write(
'<head><meta name="viewport" content="width=device-width,initial-scale=1">')
..write('<style>ul { list-style-type: none; }</style>')
..write('</head><body>');
res.write('<li><a href="..">..</a></li>');
var entities = await directory
.list(followLinks: false)
.toList()
.then((l) => List.from(l));
entities.sort((a, b) {
if (a is Directory) {
if (b is Directory) {
return a.path.compareTo(b.path);
}
return -1;
} else if (a is File) {
if (b is Directory) {
return 1;
} else if (b is File) {
return a.path.compareTo(b.path);
}
return -1;
} else if (a is Link) {
if (b is Directory) {
return 1;
} else if (b is Link) {
return a.path.compareTo(b.path);
}
return -1;
}
return 1;
});
for (var entity in entities) {
String stub;
String type;
if (entity is File) {
type = '[File]';
stub = p.basename(entity.path);
} else if (entity is Directory) {
type = '[Directory]';
stub = p.basename(entity.path);
} else if (entity is Link) {
type = '[Link]';
stub = p.basename(entity.path);
} else {
//TODO: Handle unknown type
_log.severe('Unknown file entity. Not a file, directory or link.');
type = '[]';
stub = '';
}
var href = stub;
if (relative.isNotEmpty) {
href = '/$relative/$stub';
}
if (entity is Directory) {
if (href == '') {
href = '/';
} else {
href += '/';
}
}
href = Uri.encodeFull(href);
res.write('<li><a href="$href">$type $stub</a></li>');
}
res.write('</body></html>');
return false;
}
return true;
}
void _ensureContentTypeAllowed(String mimeType, RequestContext req) {
var value = req.headers?.value('accept');
var acceptable = value == null ||
value.isNotEmpty != true ||
(mimeType.isNotEmpty == true && value.contains(mimeType) == true) ||
value.contains('*/*') == true;
if (!acceptable) {
_log.severe('Mime type [$value] is not supported');
throw AngelHttpException(
//UnsupportedError(
// 'Client requested $value, but server wanted to send $mimeType.'),
errors: [
'Client requested $value, but server wanted to send $mimeType.'
], statusCode: 406, message: '406 Not Acceptable');
}
}
/// Writes the contents of a file to a response.
Future<bool> serveFile(
File file, FileStat stat, RequestContext req, ResponseContext res) async {
res.headers['accept-ranges'] = 'bytes';
if (callback != null) {
return await req.app?.executeHandler(
(RequestContext req, ResponseContext res) =>
callback!(file, req, res),
req,
res) ??
true;
}
var type =
app.mimeTypeResolver.lookup(file.path) ?? 'application/octet-stream';
res.headers['accept-ranges'] = 'bytes';
_ensureContentTypeAllowed(type, req);
res.headers['accept-ranges'] = 'bytes';
res.contentType = MediaType.parse(type);
if (useBuffer == true) res.useBuffer();
if (req.headers == null) {
_log.severe('Missing headers in the RequestContext');
throw ArgumentError('Missing headers in the RequestContext');
}
var reqHeaders = req.headers!;
if (reqHeaders.value('range')?.startsWith('bytes=') != true) {
await res.streamFile(file);
} else {
var header = RangeHeader.parse(reqHeaders.value('range')!);
var items = RangeHeader.foldItems(header.items);
header = RangeHeader(items);
var totalFileSize = await file.length();
for (var item in header.items) {
var invalid = false;
if (item.start != -1) {
invalid = item.end != -1 && item.end < item.start;
} else {
invalid = item.end == -1;
}
if (invalid) {
throw AngelHttpException(
//Exception('Semantically invalid, or unbounded range.'),
errors: ['Semantically invalid, or unbounded range.'],
statusCode: 416,
message: 'Semantically invalid, or unbounded range.');
}
// Ensure it's within range.
if (item.start >= totalFileSize || item.end >= totalFileSize) {
throw AngelHttpException(
//Exception('Given range $item is out of bounds.'),
errors: ['Given range $item is out of bounds.'],
statusCode: 416,
message: 'Given range $item is out of bounds.');
}
}
if (header.items.isEmpty) {
throw AngelHttpException(
statusCode: 416, message: '`Range` header may not be empty.');
} else if (header.items.length == 1) {
var item = header.items[0];
Stream<List<int>> stream;
var len = 0;
var total = totalFileSize;
if (item.start == -1) {
if (item.end == -1) {
len = total;
stream = file.openRead();
} else {
len = item.end + 1;
stream = file.openRead(0, item.end + 1);
}
} else {
if (item.end == -1) {
len = total - item.start;
stream = file.openRead(item.start);
} else {
len = item.end - item.start + 1;
stream = file.openRead(item.start, item.end + 1);
}
}
res.contentType = MediaType.parse(
app.mimeTypeResolver.lookup(file.path) ??
'application/octet-stream');
res.statusCode = 206;
res.headers['content-length'] = len.toString();
res.headers['content-range'] = 'bytes ${item.toContentRange(total)}';
await stream.cast<List<int>>().pipe(res);
return false;
} else {
var transformer = RangeHeaderTransformer(
header,
app.mimeTypeResolver.lookup(file.path) ??
'application/octet-stream',
await file.length());
res.statusCode = 206;
res.headers['content-length'] =
transformer.computeContentLength(totalFileSize).toString();
res.contentType = MediaType(
'multipart', 'byteranges', {'boundary': transformer.boundary});
await file
.openRead()
.cast<List<int>>()
.transform(transformer)
.pipe(res);
return false;
}
}
return false;
}
}