X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=third-party%2Ftriemap%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fyangtools%2Ftriemap%2FCNode.java;h=9b20a1bb03103df1ace56a6c1b14059c4a725303;hb=88a92ba9395d82a38dd2250451a2c88bfe9ed63f;hp=581594346e0728aa21f1a4c313cc5afad63ad580;hpb=b08662fc364d3469e4aac44ae780a347224399f4;p=yangtools.git

diff --git a/third-party/triemap/src/main/java/org/opendaylight/yangtools/triemap/CNode.java b/third-party/triemap/src/main/java/org/opendaylight/yangtools/triemap/CNode.java
index 581594346e..9b20a1bb03 100644
--- a/third-party/triemap/src/main/java/org/opendaylight/yangtools/triemap/CNode.java
+++ b/third-party/triemap/src/main/java/org/opendaylight/yangtools/triemap/CNode.java
@@ -15,31 +15,69 @@
  */
 package org.opendaylight.yangtools.triemap;
 
-final class CNode<K, V> extends CNodeBase<K, V> {
+import com.google.common.base.Verify;
+import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
+
+final class CNode<K, V> extends MainNode<K, V> {
+    @SuppressWarnings("rawtypes")
+    private static final AtomicIntegerFieldUpdater<CNode> CSIZE_UPDATER = AtomicIntegerFieldUpdater.newUpdater(
+        CNode.class, "csize");
+
+    private static final BasicNode[] EMPTY_ARRAY = new BasicNode[0];
+    private static final int NO_SIZE = -1;
 
     final int bitmap;
     final BasicNode[] array;
     final Gen gen;
 
-    CNode(final int bitmap, final BasicNode[] array, final Gen gen) {
+    private volatile int csize = NO_SIZE;
+
+    private CNode(final Gen gen, final int bitmap, final BasicNode... array) {
         this.bitmap = bitmap;
         this.array = array;
         this.gen = gen;
     }
 
+    CNode(final Gen gen) {
+        this(gen, 0, EMPTY_ARRAY);
+    }
+
+    static <K, V> MainNode<K,V> dual(final SNode<K, V> x, final K k, final V v, final int hc, final int lev,
+            final Gen gen) {
+        return dual(x, x.hc, new SNode<>(k, v, hc), hc, lev, gen);
+    }
+
+    private static <K, V> MainNode<K,V> dual(final SNode<K, V> x, final int xhc, final SNode<K, V> y, final int yhc,
+            final int lev, final Gen gen) {
+        if (lev >= 35) {
+            return new LNode<>(x.k, x.v, y.k, y.v);
+        }
+
+        final int xidx = (xhc >>> lev) & 0x1f;
+        final int yidx = (yhc >>> lev) & 0x1f;
+        final int bmp = (1 << xidx) | (1 << yidx);
+
+        if (xidx == yidx) {
+            return new CNode<>(gen, bmp, new INode<>(gen, dual(x, xhc, y, yhc, lev + 5, gen)));
+        }
+
+        return xidx < yidx ? new CNode<>(gen, bmp, x, y) : new CNode<>(gen, bmp, y, x);
+    }
+
     // this should only be called from within read-only snapshots
     @Override
-    int cachedSize(final TrieMap<K, V> ct) {
-        final int currsz = READ_SIZE();
-        if (currsz != -1) {
-            return currsz;
+    int cachedSize(final TrieMap<?, ?> ct) {
+        int sz = csize;
+        if (sz == NO_SIZE) {
+            // We have not computed the size yet, do that now
+            sz = computeSize(ct);
+            if (!CSIZE_UPDATER.compareAndSet(this, NO_SIZE, sz)) {
+                // We have been pre-empted by some else: read the result
+                sz = csize;
+            }
         }
 
-        final int sz = computeSize(ct);
-        while (READ_SIZE () == -1) {
-            CAS_SIZE (-1, sz);
-        }
-        return READ_SIZE ();
+        return sz;
     }
 
     // lends itself towards being parallelizable by choosing
@@ -47,7 +85,7 @@ final class CNode<K, V> extends CNodeBase<K, V> {
     // => if there are concurrent size computations, they start
     // at different positions, so they are more likely to
     // to be independent
-    private int computeSize(final TrieMap<K, V> ct) {
+    private int computeSize(final TrieMap<?, ?> ct) {
         int i = 0;
         int sz = 0;
         // final int offset = (array.length > 0) ?
@@ -64,7 +102,7 @@ final class CNode<K, V> extends CNodeBase<K, V> {
             if (elem instanceof SNode) {
                 sz += 1;
             } else if (elem instanceof INode) {
-                sz += ((INode<K, V>) elem).cachedSize (ct);
+                sz += ((INode<?, ?>) elem).cachedSize(ct);
             }
             i += 1;
         }
@@ -76,7 +114,7 @@ final class CNode<K, V> extends CNodeBase<K, V> {
         BasicNode[] narr = new BasicNode[len];
         System.arraycopy(array, 0, narr, 0, len);
         narr[pos] = nn;
-        return new CNode<>(bitmap, narr, gen);
+        return new CNode<>(gen, bitmap, narr);
     }
 
     CNode<K, V> removedAt(final int pos, final int flag, final Gen gen) {
@@ -85,7 +123,7 @@ final class CNode<K, V> extends CNodeBase<K, V> {
         BasicNode[] narr = new BasicNode[len - 1];
         System.arraycopy(arr, 0, narr, 0, pos);
         System.arraycopy(arr, pos + 1, narr, pos, len - pos - 1);
-        return new CNode<>(bitmap ^ flag, narr, gen);
+        return new CNode<>(gen, bitmap ^ flag, narr);
     }
 
     CNode<K, V> insertedAt(final int pos, final int flag, final BasicNode nn, final Gen gen) {
@@ -95,7 +133,7 @@ final class CNode<K, V> extends CNodeBase<K, V> {
         System.arraycopy(array, 0, narr, 0, pos);
         narr [pos] = nn;
         System.arraycopy(array, pos, narr, pos + 1, len - pos);
-        return new CNode<>(bmp | flag, narr, gen);
+        return new CNode<>(gen, bmp | flag, narr);
     }
 
     /**
@@ -104,42 +142,30 @@ final class CNode<K, V> extends CNodeBase<K, V> {
      */
     CNode<K, V> renewed(final Gen ngen, final TrieMap<K, V> ct) {
         int i = 0;
-        BasicNode[] arr = array;
-        int len = arr.length;
-        BasicNode[] narr = new BasicNode[len];
+        final BasicNode[] arr = array;
+        final int len = arr.length;
+        final BasicNode[] narr = new BasicNode[len];
         while (i < len) {
-            BasicNode elem = arr[i];
+            final BasicNode elem = arr[i];
             if (elem instanceof INode) {
-                INode<K, V> in = (INode<K, V>) elem;
-                narr [i] = in.copyToGen(ngen, ct);
-            } else if (elem instanceof BasicNode) {
-                narr [i] = elem;
+                narr[i] = ((INode<?, ?>) elem).copyToGen(ngen, ct);
+            } else if (elem != null) {
+                narr[i] = elem;
             }
             i += 1;
         }
-        return new CNode<>(bitmap, narr, ngen);
-    }
-
-    private BasicNode resurrect(final INode<K, V> inode, final Object inodemain) {
-        if (inodemain instanceof TNode) {
-            TNode<K, V> tn = (TNode<K, V>) inodemain;
-            return tn.copyUntombed();
-        }
-
-        return inode;
+        return new CNode<>(ngen, bitmap, narr);
     }
 
     MainNode<K, V> toContracted(final int lev) {
         if (array.length == 1 && lev > 0) {
-            if (array [0] instanceof SNode) {
-                SNode<K, V> sn = (SNode<K, V>) array[0];
-                return sn.copyTombed();
-            } else {
-                return this;
+            if (array[0] instanceof SNode) {
+                return ((SNode<K, V>) array[0]).copyTombed();
             }
-        } else {
             return this;
         }
+
+        return this;
     }
 
     // - if the branching factor is 1 for this CNode, and the child
@@ -148,7 +174,7 @@ final class CNode<K, V> extends CNodeBase<K, V> {
     // returns the version of this node with at least some null-inodes
     // removed (those existing when the op began)
     // - if there are only null-i-nodes below, returns null
-    MainNode<K, V> toCompressed(final TrieMap<K, V> ct, final int lev, final Gen gen) {
+    MainNode<K, V> toCompressed(final TrieMap<?, ?> ct, final int lev, final Gen gen) {
         int bmp = bitmap;
         int i = 0;
         BasicNode[] arr = array;
@@ -156,17 +182,20 @@ final class CNode<K, V> extends CNodeBase<K, V> {
         while (i < arr.length) { // construct new bitmap
             BasicNode sub = arr[i];
             if (sub instanceof INode) {
-                INode<K, V> in = (INode<K, V>) sub;
-                MainNode<K, V> inodemain = in.gcasRead (ct);
-                assert (inodemain != null);
-                tmparray [i] = resurrect (in, inodemain);
+                final INode<?, ?> in = (INode<?, ?>) sub;
+                final MainNode<?, ?> inodemain = Verify.verifyNotNull(in.gcasRead(ct));
+                tmparray [i] = resurrect(in, inodemain);
             } else if (sub instanceof SNode) {
                 tmparray [i] = sub;
             }
             i += 1;
         }
 
-        return new CNode<K, V> (bmp, tmparray, gen).toContracted (lev);
+        return new CNode<K, V>(gen, bmp, tmparray).toContracted(lev);
+    }
+
+    private static BasicNode resurrect(final INode<?, ?> inode, final MainNode<?, ?> inodemain) {
+        return inodemain instanceof TNode ? ((TNode<?, ?>) inodemain).copyUntombed() : inode;
     }
 
     @Override
@@ -207,26 +236,4 @@ final class CNode<K, V> extends CNodeBase<K, V> {
         // elems.sorted.mkString(", "))
         return "CNode";
     }
-
-    static <K, V> MainNode<K,V> dual(final SNode<K, V> x, final int xhc, final SNode<K, V> y, final int yhc,
-            final int lev, final Gen gen) {
-        if (lev < 35) {
-            int xidx = (xhc >>> lev) & 0x1f;
-            int yidx = (yhc >>> lev) & 0x1f;
-            int bmp = (1 << xidx) | (1 << yidx);
-
-            if (xidx == yidx) {
-                INode<K, V> subinode = new INode<>(gen, dual(x, xhc, y, yhc, lev + 5, gen));
-                return new CNode<>(bmp, new BasicNode[] { subinode }, gen);
-            } else {
-                if (xidx < yidx) {
-                    return new CNode<>(bmp, new BasicNode[] { x, y }, gen);
-                } else {
-                    return new CNode<>(bmp, new BasicNode[] { y, x }, gen);
-                }
-            }
-        } else {
-            return new LNode<>(x.k, x.v, y.k, y.v);
-        }
-    }
 }