BUG-4803: introduce unordered offset maps

[yangtools.git] / common / util / src / main / java / org / opendaylight / yangtools / util / OffsetMapCache.java

diff --git a/common/util/src/main/java/org/opendaylight/yangtools/util/OffsetMapCache.java b/common/util/src/main/java/org/opendaylight/yangtools/util/OffsetMapCache.java
index 0863e286f6c37be1cc4dc9d66261a9623a38f3dc..b7ba220379146dd6be14ca1d6eb30762fd9960b1 100644 (file)
--- a/common/util/src/main/java/org/opendaylight/yangtools/util/OffsetMapCache.java
+++ b/common/util/src/main/java/org/opendaylight/yangtools/util/OffsetMapCache.java
@@ -7,12 +7,19 @@
  */
 package org.opendaylight.yangtools.util;
 
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Verify;
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableMap.Builder;
+import com.google.common.collect.ImmutableSet;
+import java.lang.reflect.Array;
 import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
 import java.util.Map;
 
 final class OffsetMapCache {
@@ -36,7 +43,59 @@ final class OffsetMapCache {
     }
 
     @SuppressWarnings("unchecked")
-    static <T> Map<T, Integer> offsetsFor(final Collection<T> args) {
+    private static <T> Map<T, Integer> offsets(final Collection<T> args) {
         return (Map<T, Integer>) CACHE.getUnchecked(args);
     }
+
+    @VisibleForTesting
+    static void invalidateCache() {
+        CACHE.invalidateAll();
+    }
+
+    static <T> Map<T, Integer> orderedOffsets(final Collection<T> args) {
+        if (args.size() == 1) {
+            return unorderedOffsets(args);
+        }
+
+        return offsets(ImmutableList.copyOf(args));
+    }
+
+    static <T> Map<T, Integer> unorderedOffsets(final Collection<T> args) {
+        if (args instanceof SingletonSet) {
+            return offsets(args);
+        }
+
+        return offsets(ImmutableSet.copyOf(args));
+    }
+
+    private static <K, V> V[] adjustArray(final Map<K, Integer> offsets, final List<K> keys, final V[] array) {
+        @SuppressWarnings("unchecked")
+        final V[] ret = (V[]) Array.newInstance(array.getClass().getComponentType(), array.length);
+
+        int i = 0;
+        for (final K k : keys) {
+            final Integer o = Verify.verifyNotNull(offsets.get(k), "Key %s not present in offsets %s", k, offsets);
+            ret[o] = array[i++];
+        }
+
+        return ret;
+    }
+
+    static <K, V> V[] adjustedArray(final Map<K, Integer> offsets, final List<K> keys, final V[] array) {
+        Verify.verify(offsets.size() == keys.size(), "Offsets %s do not match keys %s", offsets, keys);
+
+        // This relies on the fact that offsets has an ascending iterator
+        final Iterator<K> oi = offsets.keySet().iterator();
+        final Iterator<K> ki = keys.iterator();
+
+        while (oi.hasNext()) {
+            final K o = oi.next();
+            final K k = ki.next();
+            if (!k.equals(o)) {
+                return adjustArray(offsets, keys, array);
+            }
+        }
+
+        return array;
+    }
 }