1 files changed, 77 insertions, 0 deletions
diff --git a/src/main/java/com/android/tools/build/apkzlib/zip/AlignmentRules.java b/src/main/java/com/android/tools/build/apkzlib/zip/AlignmentRules.java
new file mode 100644
index 0000000..f654708
--- /dev/null
+++ b/src/main/java/com/android/tools/build/apkzlib/zip/AlignmentRules.java
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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.android.tools.build.apkzlib.zip;
+
+import com.google.common.base.Preconditions;
+import javax.annotation.Nonnull;
+
+/**
+ * Factory for instances of {@link AlignmentRule}.
+ */
+public final class AlignmentRules {
+
+    private AlignmentRules() {}
+
+    /**
+     * A rule that defines a constant alignment for all files.
+     *
+     * @param alignment the alignment
+     * @return the rule
+     */
+    public static AlignmentRule constant(int alignment) {
+        Preconditions.checkArgument(alignment > 0, "alignment <= 0");
+
+        return (String path) -> alignment;
+    }
+
+    /**
+     * A rule that defines constant alignment for all files with a certain suffix, placing no
+     * restrictions on other files.
+     *
+     * @param suffix the suffix
+     * @param alignment the alignment for paths that match the provided suffix
+     * @return the rule
+     */
+    public static AlignmentRule constantForSuffix(@Nonnull String suffix, int alignment) {
+        Preconditions.checkArgument(!suffix.isEmpty(), "suffix.isEmpty()");
+        Preconditions.checkArgument(alignment > 0, "alignment <= 0");
+
+        return (String path) -> path.endsWith(suffix) ? alignment : AlignmentRule.NO_ALIGNMENT;
+    }
+
+    /**
+     * A rule that applies other rules in order.
+     *
+     * @param rules all rules to be tried; the first rule that does not return
+     * {@link AlignmentRule#NO_ALIGNMENT} will define the alignment for a path; if there are no
+     * rules that return a value different from {@link AlignmentRule#NO_ALIGNMENT}, then
+     * {@link AlignmentRule#NO_ALIGNMENT} is returned
+     * @return the composition rule
+     */
+    public static AlignmentRule compose(@Nonnull AlignmentRule... rules) {
+        return (String path) -> {
+            for (AlignmentRule r : rules) {
+                int align = r.alignment(path);
+                if (align != AlignmentRule.NO_ALIGNMENT) {
+                    return align;
+                }
+            }
+
+            return AlignmentRule.NO_ALIGNMENT;
+        };
+    }
+}