1 files changed, 127 insertions, 0 deletions
diff --git a/jimfs/src/main/java/com/google/common/jimfs/Name.java b/jimfs/src/main/java/com/google/common/jimfs/Name.java
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index 0000000..327be75
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+++ b/jimfs/src/main/java/com/google/common/jimfs/Name.java
@@ -0,0 +1,127 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.common.jimfs;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Function;
+import com.google.common.collect.Ordering;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
+
+/**
+ * Immutable representation of a file name. Used both for the name components of paths and as the
+ * keys for directory entries.
+ *
+ * <p>A name has both a display string (used in the {@code toString()} form of a {@code Path} as
+ * well as for {@code Path} equality and sort ordering) and a canonical string, which is used for
+ * determining equality of the name during file lookup.
+ *
+ * <p>Note: all factory methods return a constant name instance when given the original string "."
+ * or "..", ensuring that those names can be accessed statically elsewhere in the code while still
+ * being equal to any names created for those values, regardless of normalization settings.
+ *
+ * @author Colin Decker
+ */
+final class Name {
+
+  /** The empty name. */
+  static final Name EMPTY = new Name("", "");
+
+  /** The name to use for a link from a directory to itself. */
+  public static final Name SELF = new Name(".", ".");
+
+  /** The name to use for a link from a directory to its parent directory. */
+  public static final Name PARENT = new Name("..", "..");
+
+  /** Creates a new name with no normalization done on the given string. */
+  @VisibleForTesting
+  static Name simple(String name) {
+    switch (name) {
+      case ".":
+        return SELF;
+      case "..":
+        return PARENT;
+      default:
+        return new Name(name, name);
+    }
+  }
+
+  /**
+   * Creates a name with the given display representation and the given canonical representation.
+   */
+  public static Name create(String display, String canonical) {
+    return new Name(display, canonical);
+  }
+
+  private final String display;
+  private final String canonical;
+
+  private Name(String display, String canonical) {
+    this.display = checkNotNull(display);
+    this.canonical = checkNotNull(canonical);
+  }
+
+  @Override
+  public boolean equals(@NullableDecl Object obj) {
+    if (obj instanceof Name) {
+      Name other = (Name) obj;
+      return canonical.equals(other.canonical);
+    }
+    return false;
+  }
+
+  @Override
+  public int hashCode() {
+    return Util.smearHash(canonical.hashCode());
+  }
+
+  @Override
+  public String toString() {
+    return display;
+  }
+
+  /** Returns an ordering that orders names by their display representation. */
+  public static Ordering<Name> displayOrdering() {
+    return DISPLAY_ORDERING;
+  }
+
+  /** Returns an ordering that orders names by their canonical representation. */
+  public static Ordering<Name> canonicalOrdering() {
+    return CANONICAL_ORDERING;
+  }
+
+  private static final Ordering<Name> DISPLAY_ORDERING =
+      Ordering.natural()
+          .onResultOf(
+              new Function<Name, String>() {
+                @Override
+                public String apply(Name name) {
+                  return name.display;
+                }
+              });
+
+  private static final Ordering<Name> CANONICAL_ORDERING =
+      Ordering.natural()
+          .onResultOf(
+              new Function<Name, String>() {
+                @Override
+                public String apply(Name name) {
+                  return name.canonical;
+                }
+              });
+}