Support caching host filesystem symlink targets to speedup DevFS updates (#6798)
diff --git a/packages/flutter_tools/lib/src/devfs.dart b/packages/flutter_tools/lib/src/devfs.dart
index 1001232..0249075 100644
--- a/packages/flutter_tools/lib/src/devfs.dart
+++ b/packages/flutter_tools/lib/src/devfs.dart
@@ -8,6 +8,7 @@
import 'package:path/path.dart' as path;
+import 'base/context.dart';
import 'build_info.dart';
import 'dart/package_map.dart';
import 'asset.dart';
@@ -16,6 +17,13 @@
typedef void DevFSProgressReporter(int progress, int max);
+class DevFSConfig {
+ /// Should DevFS assume that symlink targets are stable?
+ bool cacheSymlinks = false;
+}
+
+DevFSConfig get devFSConfig => context[DevFSConfig];
+
// A file that has been added to a DevFS.
class DevFSEntry {
DevFSEntry(this.devicePath, this.file)
@@ -30,10 +38,13 @@
String get assetPath => bundleEntry.archivePath;
final FileSystemEntity file;
+ FileSystemEntity _linkTarget;
FileStat _fileStat;
// When we scanned for files, did this still exist?
bool _exists = false;
DateTime get lastModified => _fileStat?.modified;
+ bool get _isSourceEntry => file == null;
+ bool get _isAssetEntry => bundleEntry != null;
bool get stillExists {
if (_isSourceEntry)
return true;
@@ -67,19 +78,28 @@
void _stat() {
if (_isSourceEntry)
return;
+ if (_linkTarget != null) {
+ // Stat the cached symlink target.
+ _fileStat = _linkTarget.statSync();
+ return;
+ }
_fileStat = file.statSync();
if (_fileStat.type == FileSystemEntityType.LINK) {
- // Stat the link target.
+ // Resolve, stat, and maybe cache the symlink target.
String resolved = file.resolveSymbolicLinksSync();
- _fileStat = FileStat.statSync(resolved);
+ FileSystemEntity linkTarget = new File(resolved);
+ // Stat the link target.
+ _fileStat = linkTarget.statSync();
+ if (devFSConfig.cacheSymlinks) {
+ _linkTarget = linkTarget;
+ }
}
}
- bool get _isSourceEntry => file == null;
-
- bool get _isAssetEntry => bundleEntry != null;
-
File _getFile() {
+ if (_linkTarget != null) {
+ return _linkTarget;
+ }
if (file is Link) {
// The link target.
return new File(file.resolveSymbolicLinksSync());
