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Lock-free document store—optimized for high rate atomic state changes—that concurrently commits and compacts on-disk log-structured storage files without blocking parallel in-memory updates to associative B-tree maps, spatial Q-tree maps, sequential S-tree lists, and singleton U-tree values
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// Copyright 2015-2024 Nstream, 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 swim.db;
import swim.codec.Output;
import swim.codec.Unicode;
import swim.concurrent.Cont;
import swim.recon.Recon;
import swim.structure.Num;
import swim.structure.Record;
import swim.structure.Slot;
import swim.structure.Value;
import swim.util.Builder;
import swim.util.CombinerFunction;
import swim.util.Cursor;
public final class STreeNode extends STreePage {
final STreePageRef pageRef;
final long version;
final STreePageRef[] childRefs;
final long[] knotIndexes;
protected STreeNode(STreePageRef pageRef, long version,
STreePageRef[] childRefs, long[] knotIndexes) {
this.pageRef = pageRef;
this.version = version;
this.childRefs = childRefs;
this.knotIndexes = knotIndexes;
}
@Override
public boolean isNode() {
return true;
}
@Override
public STreePageRef pageRef() {
return this.pageRef;
}
@Override
public PageType pageType() {
return PageType.NODE;
}
@Override
public long version() {
return this.version;
}
@Override
public boolean isEmpty() {
return this.pageRef.span == 0;
}
@Override
public int arity() {
return this.knotIndexes.length;
}
@Override
public int childCount() {
return this.childRefs.length;
}
@Override
public STreePageRef getChildRef(int index) {
return this.childRefs[index];
}
@Override
public STreePage getChild(int index) {
try {
return this.childRefs[index].page();
} catch (Throwable cause) {
if (Cont.isNonFatal(cause)) {
throw new StoreException(this.toDebugString(), cause);
} else {
throw cause;
}
}
}
@Override
public boolean contains(Value value) {
try {
final STreePageRef[] childRefs = this.childRefs;
for (int i = 0, n = childRefs.length; i < n; i += 1) {
if (childRefs[i].page().contains(value)) {
return true;
}
}
return false;
} catch (Throwable cause) {
if (Cont.isNonFatal(cause)) {
throw new StoreException(this.toDebugString(), cause);
} else {
throw cause;
}
}
}
@Override
public Slot getSlot(int x) {
throw new UnsupportedOperationException();
}
@Override
public Value get(long index) {
int x = this.lookup(index);
if (x >= 0) {
x += 1;
} else {
x = -(x + 1);
}
final long i = x == 0 ? index : index - this.knotIndexes[x - 1];
return this.getChild(x).get(i);
}
@Override
public Slot getEntry(long index) {
int x = this.lookup(index);
if (x >= 0) {
x += 1;
} else {
x = -(x + 1);
}
final long i = x == 0 ? index : index - this.knotIndexes[x - 1];
return this.getChild(x).getEntry(i);
}
int lookup(long index) {
final long[] knotIndexes = this.knotIndexes;
int low = 0;
int high = knotIndexes.length - 1;
while (low <= high) {
final int x = (low + high) >>> 1;
final int order = Long.compare(index, knotIndexes[x]);
if (order > 0) {
low = x + 1;
} else if (order < 0) {
high = x - 1;
} else {
return x;
}
}
return -(low + 1);
}
@Override
public STreePage updated(long index, Value newValue, long newVersion) {
int x = this.lookup(index);
if (x >= 0) {
x += 1;
} else {
x = -(x + 1);
}
final long i = x == 0 ? index : index - this.knotIndexes[x - 1];
final STreePage oldPage = this.getChild(x);
final STreePage newPage = oldPage.updated(i, newValue, newVersion);
if (oldPage != newPage) {
if (oldPage.span() != newPage.span() && this.pageRef.context.pageShouldSplit(newPage)) {
return this.updatedPageSplit(x, newPage, oldPage, newVersion);
} else {
return this.updatedPage(x, newPage, oldPage, newVersion);
}
} else {
return this;
}
}
STreeNode updatedPage(int x, STreePage newPage, STreePage oldPage, long newVersion) {
final STreePageRef[] oldChildRefs = this.childRefs;
final int n = oldChildRefs.length;
final STreePageRef[] newChildRefs = new STreePageRef[n];
System.arraycopy(oldChildRefs, 0, newChildRefs, 0, n);
newChildRefs[x] = newPage.pageRef();
final long[] oldKnotIndexes = this.knotIndexes;
final long[] newKnotIndexes;
long newSpan;
if (n - 1 > 0) {
newKnotIndexes = new long[n - 1];
if (x > 0) {
System.arraycopy(oldKnotIndexes, 0, newKnotIndexes, 0, x);
newSpan = oldKnotIndexes[x - 1];
} else {
newSpan = 0L;
}
for (int i = x; i < n - 1; i += 1) {
newSpan += newChildRefs[i].span;
newKnotIndexes[i] = newSpan;
}
newSpan += newChildRefs[n - 1].span;
} else {
newKnotIndexes = STreeNode.EMPTY_KNOT_INDEXES;
newSpan = 0L;
}
return STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion,
newSpan, Value.absent(), newChildRefs, newKnotIndexes);
}
STreeNode updatedPageSplit(int x, STreePage newPage, STreePage oldPage, long newVersion) {
final STreePageRef[] oldChildRefs = this.childRefs;
final int n = oldChildRefs.length + 1;
final STreePageRef[] newChildRefs = new STreePageRef[n];
System.arraycopy(oldChildRefs, 0, newChildRefs, 0, x);
final int y = newPage.arity() >>> 1;
final STreePage newLeftPage = newPage.splitLeft(y, newVersion);
final STreePage newRightPage = newPage.splitRight(y, newVersion);
newChildRefs[x] = newLeftPage.pageRef();
newChildRefs[x + 1] = newRightPage.pageRef();
System.arraycopy(oldChildRefs, x + 1, newChildRefs, x + 2, n - (x + 2));
return STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion, Value.absent(), newChildRefs);
}
STreeNode updatedPageMerge(int x, STreeNode newPage, STreePage oldPage, long newVersion) {
final STreePageRef[] oldChildRefs = this.childRefs;
final STreePageRef[] mergePages = newPage.childRefs;
final int k = mergePages.length;
final int n = oldChildRefs.length + (k - 1);
final STreePageRef[] newChildRefs = new STreePageRef[n];
System.arraycopy(oldChildRefs, 0, newChildRefs, 0, x);
System.arraycopy(mergePages, 0, newChildRefs, x, k);
System.arraycopy(oldChildRefs, x + 1, newChildRefs, x + k, n - (x + k));
return STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion, Value.absent(), newChildRefs);
}
@Override
public STreePage inserted(long index, Value key, Value newValue, long newVersion) {
int x = this.lookup(index);
if (x >= 0) {
x += 1;
} else {
x = -(x + 1);
}
final long i = x == 0 ? index : index - this.knotIndexes[x - 1];
final STreePage oldPage = this.getChild(x);
final STreePage newPage = oldPage.inserted(i, key, newValue, newVersion);
if (oldPage != newPage) {
if (this.pageRef.context.pageShouldSplit(newPage)) {
return this.updatedPageSplit(x, newPage, oldPage, newVersion);
} else {
return this.updatedPage(x, newPage, oldPage, newVersion);
}
} else {
return this;
}
}
@Override
public STreePage removed(long index, long newVersion) {
int x = this.lookup(index);
if (x >= 0) {
x += 1;
} else {
x = -(x + 1);
}
final long i = x == 0 ? index : index - this.knotIndexes[x - 1];
final STreePage oldPage = this.getChild(x);
final STreePage newPage = oldPage.removed(i, newVersion);
if (oldPage != newPage) {
return this.replacedPage(x, newPage, oldPage, newVersion);
} else {
return this;
}
}
STreePage replacedPage(int x, STreePage newPage, STreePage oldPage, long newVersion) {
if (!newPage.isEmpty()) {
if (newPage.isNode() && this.pageRef.context.pageShouldMerge(newPage)) {
return this.updatedPageMerge(x, (STreeNode) newPage, oldPage, newVersion);
} else {
return this.updatedPage(x, newPage, oldPage, newVersion);
}
} else if (this.childRefs.length > 2) {
return this.removedPage(x, newPage, oldPage, newVersion);
} else if (this.childRefs.length > 1) {
if (x == 0) {
return this.getChild(1);
} else {
return this.getChild(0);
}
} else {
return STreeLeaf.empty(this.pageRef.context, this.pageRef.stem, newVersion);
}
}
STreeNode removedPage(int x, STreePage newPage, STreePage oldPage, long newVersion) {
final STreePageRef[] oldChildRefs = this.childRefs;
final int n = oldChildRefs.length - 1;
final STreePageRef[] newChildRefs = new STreePageRef[n];
System.arraycopy(oldChildRefs, 0, newChildRefs, 0, x);
System.arraycopy(oldChildRefs, x + 1, newChildRefs, x, n - x);
final long[] oldKnotIndexes = this.knotIndexes;
final long[] newKnotIndexes = new long[n - 1];
long newSpan;
if (x > 0) {
System.arraycopy(oldKnotIndexes, 0, newKnotIndexes, 0, x);
newSpan = oldKnotIndexes[x - 1];
} else {
newSpan = 0L;
}
for (int i = x; i < n - 1; i += 1) {
newSpan += newChildRefs[i].span;
newKnotIndexes[i] = newSpan;
}
newSpan += newChildRefs[n - 1].span;
return STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion,
newSpan, Value.absent(), newChildRefs, newKnotIndexes);
}
@Override
public STreePage removed(Object object, long newVersion) {
try {
final STreePageRef[] childRefs = this.childRefs;
for (int x = 0, n = childRefs.length; x < n; x += 1) {
final STreePage oldPage = childRefs[x].page();
final STreePage newPage = oldPage.removed(object, newVersion);
if (oldPage != newPage) {
return this.replacedPage(x, newPage, oldPage, newVersion);
}
}
return this;
} catch (Throwable cause) {
if (Cont.isNonFatal(cause)) {
throw new StoreException(this.toDebugString(), cause);
} else {
throw cause;
}
}
}
@Override
public STreePage drop(long lower, long newVersion) {
try {
if (lower > 0L) {
if (lower < span()) {
int x = this.lookup(lower);
if (x >= 0) {
x += 1;
} else {
x = -(x + 1);
}
final long i = x == 0 ? lower : lower - this.knotIndexes[x - 1];
final STreePageRef[] oldChildRefs = this.childRefs;
final int k = oldChildRefs.length;
final int n = k - x;
if (n > 1) {
final STreeNode newNode;
if (x > 0) {
final STreePageRef[] newChildRefs = new STreePageRef[n];
System.arraycopy(oldChildRefs, x, newChildRefs, 0, n);
newNode = STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion,
Value.absent(), newChildRefs);
} else {
newNode = this;
}
if (i > 0L) {
final STreePage oldPage = oldChildRefs[x].page();
final STreePage newPage = oldPage.drop(i, newVersion);
return newNode.replacedPage(0, newPage, oldPage, newVersion);
} else {
return newNode;
}
} else {
return oldChildRefs[x].page().drop(i, newVersion);
}
} else {
return STreeLeaf.empty(this.pageRef.context, this.pageRef.stem, newVersion);
}
} else {
return this;
}
} catch (Throwable cause) {
if (Cont.isNonFatal(cause)) {
throw new StoreException(this.toDebugString(), cause);
} else {
throw cause;
}
}
}
@Override
public STreePage take(long upper, long newVersion) {
try {
if (upper < this.span()) {
if (upper > 0L) {
int x = this.lookup(upper);
if (x >= 0) {
x += 1;
} else {
x = -(x + 1);
}
final long i = x == 0 ? upper : upper - this.knotIndexes[x - 1];
final STreePageRef[] oldChildRefs = this.childRefs;
final int k = oldChildRefs.length;
final int n = i == 0 ? x : x + 1;
if (n > 1) {
final STreeNode newNode;
if (x < k) {
final STreePageRef[] newChildRefs = new STreePageRef[n];
System.arraycopy(oldChildRefs, 0, newChildRefs, 0, n);
final long[] newKnotIndexes = new long[n - 1];
System.arraycopy(this.knotIndexes, 0, newKnotIndexes, 0, n - 1);
final long newSpan = newKnotIndexes[n - 2] + newChildRefs[n - 1].span;
newNode = STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion,
newSpan, Value.absent(), newChildRefs, newKnotIndexes);
} else {
newNode = this;
}
if (i > 0L) {
final STreePage oldPage = oldChildRefs[x].page();
final STreePage newPage = oldPage.take(i, newVersion);
return newNode.replacedPage(x, newPage, oldPage, newVersion);
} else {
return newNode;
}
} else if (i > 0L) {
return oldChildRefs[0].page().take(i, newVersion);
} else {
return oldChildRefs[0].page();
}
} else {
return STreeLeaf.empty(this.pageRef.context, this.pageRef.stem, newVersion);
}
} else {
return this;
}
} catch (Throwable cause) {
if (Cont.isNonFatal(cause)) {
throw new StoreException(this.toDebugString(), cause);
} else {
throw cause;
}
}
}
@Override
public long indexOf(Object object) {
try {
final STreePageRef[] childRefs = this.childRefs;
long k = 0;
for (int x = 0, n = childRefs.length; x < n; x += 1) {
final STreePage page = childRefs[x].page();
final long i = page.indexOf(object);
if (i >= 0L) {
return k + i;
}
k += page.span();
}
return -1L;
} catch (Throwable cause) {
if (Cont.isNonFatal(cause)) {
throw new StoreException(this.toDebugString(), cause);
} else {
throw cause;
}
}
}
@Override
public long lastIndexOf(Object object) {
try {
final STreePageRef[] childRefs = this.childRefs;
long k = span();
for (int x = childRefs.length - 1; x >= 0; x -= 1) {
final STreePage page = childRefs[x].page();
final long i = page.lastIndexOf(object);
k -= page.span();
if (i >= 0L) {
return k + 1;
}
}
return -1L;
} catch (Throwable cause) {
if (Cont.isNonFatal(cause)) {
throw new StoreException(this.toDebugString(), cause);
} else {
throw cause;
}
}
}
@Override
public void copyToArray(Object[] array, int offset) {
try {
final STreePageRef[] childRefs = this.childRefs;
for (int x = 0, n = childRefs.length; x < n; x += 1) {
final STreePage page = childRefs[x].page();
page.copyToArray(array, offset);
offset += page.span();
}
} catch (Throwable cause) {
if (Cont.isNonFatal(cause)) {
throw new StoreException(this.toDebugString(), cause);
} else {
throw cause;
}
}
}
@Override
public STreeNode balanced(long newVersion) {
if (this.childRefs.length > 1 && this.pageRef.context.pageShouldSplit(this)) {
final int x = this.knotIndexes.length >>> 1;
return this.split(x, newVersion);
} else {
return this;
}
}
@Override
public STreeNode split(int x, long newVersion) {
final STreePageRef[] newChildRefs = new STreePageRef[2];
final STreeNode newLeftPage = this.splitLeft(x, newVersion);
final STreeNode newRightPage = this.splitRight(x, newVersion);
newChildRefs[0] = newLeftPage.pageRef();
newChildRefs[1] = newRightPage.pageRef();
final long[] newKnotIndexes = new long[1];
newKnotIndexes[0] = newLeftPage.span();
return STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion,
this.pageRef.span, Value.absent(), newChildRefs, newKnotIndexes);
}
@Override
public STreeNode splitLeft(int x, long newVersion) {
final STreePageRef[] oldChildRefs = this.childRefs;
final STreePageRef[] newChildRefs = new STreePageRef[x + 1];
System.arraycopy(oldChildRefs, 0, newChildRefs, 0, x + 1);
final long[] oldKnotIndexes = this.knotIndexes;
final long[] newKnotIndexes = new long[x];
System.arraycopy(oldKnotIndexes, 0, newKnotIndexes, 0, x);
long newSpan = 0L;
for (int i = 0; i <= x; i += 1) {
newSpan += newChildRefs[i].span;
}
return STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion,
newSpan, Value.absent(), newChildRefs, newKnotIndexes);
}
@Override
public STreeNode splitRight(int x, long newVersion) {
final STreePageRef[] oldChildRefs = this.childRefs;
final int y = oldChildRefs.length - (x + 1);
final STreePageRef[] newChildRefs = new STreePageRef[y];
System.arraycopy(oldChildRefs, x + 1, newChildRefs, 0, y);
final long[] newKnotIndexes = new long[y - 1];
long newSpan;
if (y > 0) {
newSpan = newChildRefs[0].span;
for (int i = 1; i < y; i += 1) {
newKnotIndexes[i - 1] = newSpan;
newSpan += newChildRefs[i].span;
}
} else {
newSpan = 0L;
}
return STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion,
newSpan, Value.absent(), newChildRefs, newKnotIndexes);
}
@Override
public int pageSize() {
return this.pageRef.pageSize();
}
@Override
public int diffSize() {
return this.pageRef.diffSize();
}
@Override
public long treeSize() {
return this.pageRef.treeSize();
}
@Override
void memoizeSize(STreePageRef pageRef) {
int pageSize = 12; // "@snode(stem:"
pageSize += Recon.sizeOf(Num.from(this.pageRef.stem));
pageSize += 3; // ",v:"
pageSize += Recon.sizeOf(Num.from(this.version));
pageSize += 1; // ')'
final STreePageRef[] childRefs = this.childRefs;
final int n = childRefs.length;
final long[] knotIndexes = this.knotIndexes;
int diffSize = 0;
long treeSize = 0L;
if (n > 0) {
pageSize += 1; // '{'
for (int i = 0; i < n; i += 1) {
if (i > 0) {
final long index = knotIndexes[i - 1];
pageSize += 9; // ",@knot(i:"
pageSize += Recon.sizeOf(Num.from(index));
pageSize += 2; // "),"
}
final STreePageRef childRef = childRefs[i];
pageSize += childRef.pageRefSize();
if (this.version == childRef.softVersion()) {
diffSize += childRef.diffSize();
}
treeSize += childRef.treeSize();
}
pageSize += 1; // '}'
pageSize += 1; // '\n'
}
diffSize += pageSize;
treeSize += pageSize;
pageRef.pageSize = pageSize; // Must match bytes written by writePage
pageRef.diffSize = diffSize; // Must match bytes written by writeDiff
pageRef.treeSize = treeSize;
}
@Override
public Value toHeader() {
final Record header = Record.create(2).slot("stem", this.pageRef.stem)
.slot("v", this.version);
return Record.create(1).attr("snode", header);
}
@Override
public Value toValue() {
final Record record = (Record) this.toHeader();
final STreePageRef[] childRefs = this.childRefs;
final long[] knotIndexes = this.knotIndexes;
for (int i = 0, n = childRefs.length; i < n; i += 1) {
if (i > 0) {
record.add(Record.create(1).attr("knot", Record.create(1).slot("i", knotIndexes[i - 1])));
}
record.add(childRefs[i].toValue());
}
return record;
}
@Override
public STreeNode reduced(Value identity, CombinerFunction accumulator,
CombinerFunction combiner, long newVersion) {
final STreePageRef[] oldChildRefs = this.childRefs;
final int n = oldChildRefs.length;
final STreePageRef[] newChildRefs = new STreePageRef[n];
for (int i = 0; i < n; i += 1) {
newChildRefs[i] = oldChildRefs[i].reduced(identity, accumulator, combiner, newVersion);
}
// assert n > 0;
Value fold = newChildRefs[0].fold();
for (int i = 1; i < n; i += 1) {
fold = combiner.combine(fold, newChildRefs[i].fold());
}
return STreeNode.create(this.pageRef.context, this.pageRef.stem, newVersion,
this.pageRef.span, fold, newChildRefs, this.knotIndexes);
}
@Override
public STreeNode evacuated(int post, long version) {
final int oldPost = this.pageRef.post;
if (oldPost != 0 && oldPost < post) {
final STreePageRef[] oldChildRefs = this.childRefs;
final int n = oldChildRefs.length;
final STreePageRef[] newChildRefs = new STreePageRef[n];
for (int i = 0; i < n; i += 1) {
final STreePageRef oldChildRef = oldChildRefs[i];
final STreePageRef newChildRef = oldChildRef.evacuated(post, version);
newChildRefs[i] = newChildRef;
if (oldChildRef != newChildRef) {
i += 1;
if (i < n) {
System.arraycopy(oldChildRefs, i, newChildRefs, i, n - i);
}
return STreeNode.create(this.pageRef.context, this.pageRef.stem, version,
this.pageRef.span, this.pageRef.fold, newChildRefs, this.knotIndexes);
}
}
}
return this;
}
@Override
public STreeNode committed(int zone, long base, long version) {
final STreePageRef[] oldChildRefs = this.childRefs;
final int n = oldChildRefs.length;
final STreePageRef[] newChildRefs = new STreePageRef[n];
long step = base;
for (int i = 0; i < n; i += 1) {
final STreePageRef oldChildRef = oldChildRefs[i];
if (!oldChildRef.isCommitted()) {
final STreePageRef newChildRef = oldChildRef.committed(zone, step, version);
newChildRefs[i] = newChildRef;
step += newChildRef.diffSize();
} else {
newChildRefs[i] = oldChildRef;
}
}
return STreeNode.create(this.pageRef.context, this.pageRef.stem, version, zone, step,
this.pageRef.span, this.pageRef.fold, newChildRefs, this.knotIndexes);
}
@Override
public STreeNode uncommitted(long version) {
final STreePageRef[] oldChildRefs = this.childRefs;
final int n = oldChildRefs.length;
final STreePageRef[] newChildRefs = new STreePageRef[n];
for (int i = 0; i < n; i += 1) {
newChildRefs[i] = oldChildRefs[i].uncommitted(version);
}
return STreeNode.create(this.pageRef.context, this.pageRef.stem, version,
this.pageRef.span, this.pageRef.fold, newChildRefs, this.knotIndexes);
}
@Override
public void writePage(Output output) {
Recon.write(output, this.toHeader());
this.writePageContent(output);
output.write('\n');
}
void writePageContent(Output output) {
final STreePageRef[] childRefs = this.childRefs;
final int n = childRefs.length;
final long[] knotIndexes = this.knotIndexes;
if (n > 0) {
output.write('{');
for (int i = 0; i < n; i += 1) {
if (i > 0) {
output.write(',').write('@').write('k').write('n').write('o').write('t')
.write('(').write('i').write(':');
Recon.write(output, Num.from(knotIndexes[i - 1]));
output.write(')').write(',');
}
childRefs[i].writePageRef(output);
}
output.write('}');
}
}
@Override
public void writeDiff(Output output) {
final STreePageRef[] childRefs = this.childRefs;
for (int i = 0, n = childRefs.length; i < n; i += 1) {
final STreePageRef childRef = childRefs[i];
if (this.version == childRef.softVersion()) {
childRef.writeDiff(output);
}
}
this.writePage(output);
}
@Override
public void buildDiff(Builder builder) {
final STreePageRef[] childRefs = this.childRefs;
for (int i = 0, n = childRefs.length; i < n; i += 1) {
final STreePageRef childRef = childRefs[i];
if (this.version == childRef.softVersion()) {
childRef.buildDiff(builder);
}
}
builder.add(this);
}
@Override
public STreePage loadTree(PageLoader pageLoader) {
final STreePageRef[] childRefs = this.childRefs;
for (int i = 0, n = childRefs.length; i < n; i += 1) {
childRefs[i].loadTree(pageLoader);
}
return this;
}
@Override
public void soften(long version) {
final STreePageRef[] childRefs = this.childRefs;
for (int i = 0, n = childRefs.length; i < n; i += 1) {
childRefs[i].soften(version);
}
}
@Override
public Cursor cursor() {
return new STreeNodeDepthCursor(this, Integer.MAX_VALUE);
}
@Override
public Cursor depthCursor(int maxDepth) {
return new STreeNodeDepthCursor(this, maxDepth);
}
@Override
public Cursor deltaCursor(long sinceVersion) {
return new STreeNodeDeltaCursor(this, sinceVersion);
}
@Override
public String toString() {
final Output output = Unicode.stringOutput(this.pageSize() - 1); // ignore trailing '\n'
Recon.write(output, this.toHeader());
this.writePageContent(output);
return output.bind();
}
static final long[] EMPTY_KNOT_INDEXES = new long[0];
public static STreeNode create(PageContext context, int stem, long version,
int post, int zone, long base, long span, Value fold,
STreePageRef[] childRefs, long[] knotIndexes) {
final STreePageRef pageRef = new STreePageRef(context, PageType.NODE, stem,
post, zone, base, span, fold);
final STreeNode page = new STreeNode(pageRef, version, childRefs, knotIndexes);
pageRef.page = page;
return page;
}
public static STreeNode create(PageContext context, int stem, long version,
int zone, long base, long span, Value fold,
STreePageRef[] childRefs, long[] knotIndexes) {
int post = zone;
for (int i = 0, n = childRefs.length; i < n; i += 1) {
final int childPost = childRefs[i].post;
if (childPost != 0) {
post = post == 0 ? childPost : Math.min(post, childPost);
}
}
return STreeNode.create(context, stem, version, post, zone, base, span, fold, childRefs, knotIndexes);
}
public static STreeNode create(PageContext context, int stem, long version, long span,
Value fold, STreePageRef[] childRefs, long[] knotIndexes) {
return STreeNode.create(context, stem, version, 0, 0L, span, fold, childRefs, knotIndexes);
}
public static STreeNode create(PageContext context, int stem, long version,
Value fold, STreePageRef[] childRefs) {
final int n = childRefs.length - 1;
final long[] knotIndexes = new long[n];
int post = 0;
long span = 0;
for (int i = 0; i < n; i += 1) {
final STreePageRef childRef = childRefs[i];
final int childPost = childRef.post;
if (childPost != 0) {
post = post == 0 ? childPost : Math.min(post, childPost);
}
span += childRef.span;
knotIndexes[i] = span;
}
span += childRefs[n].span;
return STreeNode.create(context, stem, version, post, 0, 0L, span, fold, childRefs, knotIndexes);
}
public static STreeNode fromValue(STreePageRef pageRef, Value value) {
Throwable cause = null;
try {
final Value header = value.header("snode");
final long version = header.get("v").longValue();
final Record tail = value.tail();
final int n = tail.size() >>> 1;
final STreePageRef[] childRefs = new STreePageRef[n + 1];
final long[] knotIndexes = new long[n];
childRefs[0] = STreePageRef.fromValue(pageRef.context, pageRef.stem,
tail.get(0).toValue());
for (int i = 1; i <= n; i += 1) {
knotIndexes[i - 1] = tail.get(2 * i - 1).header("knot").get("i").longValue();
childRefs[i] = STreePageRef.fromValue(pageRef.context, pageRef.stem,
tail.get(2 * i).toValue());
}
return new STreeNode(pageRef, version, childRefs, knotIndexes);
} catch (Throwable error) {
if (Cont.isNonFatal(error)) {
cause = error;
} else {
throw error;
}
}
final Output message = Unicode.stringOutput("Malformed snode: ");
Recon.write(message, value);
throw new StoreException(message.bind(), cause);
}
}