1 files changed, 51 insertions, 0 deletions
diff --git a/node_modules/dir-compare/src/symlink/loopDetector.js b/node_modules/dir-compare/src/symlink/loopDetector.js
new file mode 100644
index 0000000..0376ebb
--- /dev/null
+++ b/node_modules/dir-compare/src/symlink/loopDetector.js
@@ -0,0 +1,51 @@
+var fs = require('fs')
+
+/**
+ * Provides symlink loop detection to directory traversal algorithm.
+ */
+module.exports = {
+	detectLoop: function (entry, symlinkCache) {
+		if (entry && entry.isSymlink) {
+			var realPath = fs.realpathSync(entry.absolutePath)
+			if (symlinkCache[realPath]) {
+				return true
+			}
+		}
+		return false
+	},
+
+	initSymlinkCache: function() {
+		return {
+			dir1: {},
+			dir2: {}
+		}
+	},
+
+	updateSymlinkCache: function(symlinkCache, rootEntry1, rootEntry2, loopDetected1, loopDetected2) {
+		var symlinkCachePath1, symlinkCachePath2
+		if (rootEntry1 && !loopDetected1) {
+			symlinkCachePath1 = rootEntry1.isSymlink ? fs.realpathSync(rootEntry1.absolutePath) : rootEntry1.absolutePath
+			symlinkCache.dir1[symlinkCachePath1] = true
+		}
+		if (rootEntry2 && !loopDetected2) {
+			symlinkCachePath2 = rootEntry2.isSymlink ? fs.realpathSync(rootEntry2.absolutePath) : rootEntry2.absolutePath
+			symlinkCache.dir2[symlinkCachePath2] = true
+		}
+	},
+
+	cloneSymlinkCache: function (symlinkCache) {
+		return {
+			dir1: shallowClone(symlinkCache.dir1),
+			dir2: shallowClone(symlinkCache.dir2)
+		}
+	},
+}
+
+function shallowClone(obj) {
+	var cloned = {}
+	Object.keys(obj).forEach(function (key) {
+		cloned[key] = obj[key]
+	})
+	return cloned
+}
+