2 * (C) Copyright 2016 Pantheon Technologies, s.r.o. and others.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 package org.opendaylight.yangtools.triemap;
18 final class CNode<K, V> extends CNodeBase<K, V> {
19 private static final BasicNode[] EMPTY_ARRAY = new BasicNode[0];
22 final BasicNode[] array;
25 private CNode(final Gen gen, final int bitmap, final BasicNode... array) {
31 CNode(final Gen gen) {
32 this(gen, 0, EMPTY_ARRAY);
35 static <K, V> MainNode<K,V> dual(final SNode<K, V> x, final int xhc, final SNode<K, V> y, final int yhc,
36 final int lev, final Gen gen) {
38 return new LNode<>(x.k, x.v, y.k, y.v);
41 final int xidx = (xhc >>> lev) & 0x1f;
42 final int yidx = (yhc >>> lev) & 0x1f;
43 final int bmp = (1 << xidx) | (1 << yidx);
46 INode<K, V> subinode = new INode<>(gen, dual(x, xhc, y, yhc, lev + 5, gen));
47 return new CNode<>(gen, bmp, subinode);
50 return xidx < yidx ? new CNode<>(gen, bmp, x, y) : new CNode<>(gen, bmp, y, x);
53 // this should only be called from within read-only snapshots
55 int cachedSize(final TrieMap<K, V> ct) {
56 final int currsz = READ_SIZE();
61 final int sz = computeSize(ct);
62 while (READ_SIZE () == -1) {
68 // lends itself towards being parallelizable by choosing
69 // a random starting offset in the array
70 // => if there are concurrent size computations, they start
71 // at different positions, so they are more likely to
73 private int computeSize(final TrieMap<K, V> ct) {
76 // final int offset = (array.length > 0) ?
77 // // util.Random.nextInt(array.length) /* <-- benchmarks show that
78 // // this causes observable contention */
79 // scala.concurrent.forkjoin.ThreadLocalRandom.current.nextInt (0,
84 while (i < array.length) {
85 int pos = (i + offset) % array.length;
86 BasicNode elem = array [pos];
87 if (elem instanceof SNode) {
89 } else if (elem instanceof INode) {
90 sz += ((INode<K, V>) elem).cachedSize (ct);
97 CNode<K, V> updatedAt(final int pos, final BasicNode nn, final Gen gen) {
98 int len = array.length;
99 BasicNode[] narr = new BasicNode[len];
100 System.arraycopy(array, 0, narr, 0, len);
102 return new CNode<>(gen, bitmap, narr);
105 CNode<K, V> removedAt(final int pos, final int flag, final Gen gen) {
106 BasicNode[] arr = array;
107 int len = arr.length;
108 BasicNode[] narr = new BasicNode[len - 1];
109 System.arraycopy(arr, 0, narr, 0, pos);
110 System.arraycopy(arr, pos + 1, narr, pos, len - pos - 1);
111 return new CNode<>(gen, bitmap ^ flag, narr);
114 CNode<K, V> insertedAt(final int pos, final int flag, final BasicNode nn, final Gen gen) {
115 int len = array.length;
117 BasicNode[] narr = new BasicNode[len + 1];
118 System.arraycopy(array, 0, narr, 0, pos);
120 System.arraycopy(array, pos, narr, pos + 1, len - pos);
121 return new CNode<>(gen, bmp | flag, narr);
125 * Returns a copy of this cnode such that all the i-nodes below it are
126 * copied to the specified generation `ngen`.
128 CNode<K, V> renewed(final Gen ngen, final TrieMap<K, V> ct) {
130 BasicNode[] arr = array;
131 int len = arr.length;
132 BasicNode[] narr = new BasicNode[len];
134 BasicNode elem = arr[i];
135 if (elem instanceof INode) {
136 INode<K, V> in = (INode<K, V>) elem;
137 narr [i] = in.copyToGen(ngen, ct);
138 } else if (elem != null) {
143 return new CNode<>(ngen, bitmap, narr);
146 private BasicNode resurrect(final INode<K, V> inode, final Object inodemain) {
147 if (inodemain instanceof TNode) {
148 TNode<K, V> tn = (TNode<K, V>) inodemain;
149 return tn.copyUntombed();
155 MainNode<K, V> toContracted(final int lev) {
156 if (array.length == 1 && lev > 0) {
157 if (array[0] instanceof SNode) {
158 final SNode<K, V> sn = (SNode<K, V>) array[0];
159 return sn.copyTombed();
167 // - if the branching factor is 1 for this CNode, and the child
168 // is a tombed SNode, returns its tombed version
169 // - otherwise, if there is at least one non-null node below,
170 // returns the version of this node with at least some null-inodes
171 // removed (those existing when the op began)
172 // - if there are only null-i-nodes below, returns null
173 MainNode<K, V> toCompressed(final TrieMap<K, V> ct, final int lev, final Gen gen) {
176 BasicNode[] arr = array;
177 BasicNode[] tmparray = new BasicNode[arr.length];
178 while (i < arr.length) { // construct new bitmap
179 BasicNode sub = arr[i];
180 if (sub instanceof INode) {
181 INode<K, V> in = (INode<K, V>) sub;
182 MainNode<K, V> inodemain = in.gcasRead (ct);
183 assert (inodemain != null);
184 tmparray [i] = resurrect (in, inodemain);
185 } else if (sub instanceof SNode) {
191 return new CNode<K, V>(gen, bmp, tmparray).toContracted(lev);
195 String string(final int lev) {
196 // "CNode %x\n%s".format(bitmap, array.map(_.string(lev +
197 // 1)).mkString("\n"));
202 * quiescently consistent - don't call concurrently to anything
205 // protected Seq<K,V> collectElems() {
207 // case sn: SNode[K, V] => Some(sn.kvPair)
208 // case in: INode[K, V] => in.mainnode match {
209 // case tn: TNode[K, V] => Some(tn.kvPair)
210 // case ln: LNode[K, V] => ln.listmap.toList
211 // case cn: CNode[K, V] => cn.collectElems
216 // protected Seq<String> collectLocalElems() {
217 // // array flatMap {
218 // // case sn: SNode[K, V] => Some(sn.kvPair._2.toString)
219 // // case in: INode[K, V] => Some(in.toString.drop(14) + "(" + in.gen +
226 public String toString () {
227 // val elems = collectLocalElems
228 // "CNode(sz: %d; %s)".format(elems.size,
229 // elems.sorted.mkString(", "))