1 /*******************************************************************************
2 * Copyright (c) 2010, 2015 Ericsson, École Polytechnique de Montréal, and others
4 * All rights reserved. This program and the accompanying materials are
5 * made available under the terms of the Eclipse Public License v1.0 which
6 * accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
10 * Alexandre Montplaisir - Initial API and implementation
11 * Florian Wininger - Add Extension and Leaf Node
12 * Patrick Tasse - Keep interval list sorted on insert
13 *******************************************************************************/
15 package org
.eclipse
.tracecompass
.internal
.statesystem
.core
.backend
.historytree
;
17 import java
.io
.IOException
;
18 import java
.io
.PrintWriter
;
19 import java
.nio
.ByteBuffer
;
20 import java
.nio
.ByteOrder
;
21 import java
.nio
.channels
.FileChannel
;
22 import java
.util
.ArrayList
;
23 import java
.util
.Collections
;
24 import java
.util
.List
;
25 import java
.util
.concurrent
.locks
.ReentrantReadWriteLock
;
27 import org
.eclipse
.tracecompass
.statesystem
.core
.exceptions
.TimeRangeException
;
28 import org
.eclipse
.tracecompass
.statesystem
.core
.interval
.ITmfStateInterval
;
29 import org
.eclipse
.tracecompass
.statesystem
.core
.statevalue
.TmfStateValue
;
32 * The base class for all the types of nodes that go in the History Tree.
34 * @author Alexandre Montplaisir
36 public abstract class HTNode
{
38 // ------------------------------------------------------------------------
40 // ------------------------------------------------------------------------
45 public static enum NodeType
{
47 * Core node, which is a "front" node, at any level of the tree except
48 * the bottom-most one. It has children, and may have extensions.
52 * Leaf node, which is a node at the last bottom level of the tree. It
53 * cannot have any children or extensions.
58 * Determine a node type by reading a serialized byte.
61 * The byte representation of the node type
62 * @return The corresponding NodeType
64 * If the NodeType is unrecognized
66 public static NodeType
fromByte(byte rep
) throws IOException
{
73 throw new IOException();
78 * Get the byte representation of this node type. It can then be read
79 * with {@link #fromByte}.
81 * @return The byte matching this node type
83 public byte toByte() {
90 throw new IllegalStateException();
98 * 16 - 2x long (start time, end time)
99 * 16 - 4x int (seq number, parent seq number, intervalcount,
100 * strings section pos.)
101 * 1 - byte (done or not)
104 private static final int COMMON_HEADER_SIZE
= 34;
106 // ------------------------------------------------------------------------
108 // ------------------------------------------------------------------------
110 /* Configuration of the History Tree to which belongs this node */
111 private final HTConfig fConfig
;
113 /* Time range of this node */
114 private final long fNodeStart
;
115 private long fNodeEnd
;
117 /* Sequence number = position in the node section of the file */
118 private final int fSequenceNumber
;
119 private int fParentSequenceNumber
; /* = -1 if this node is the root node */
121 /* Where the Strings section begins (from the start of the node */
122 private int fStringSectionOffset
;
124 /* Sum of bytes of all intervals in the node */
125 private int fSizeOfIntervalSection
;
127 /* True if this node was read from disk (meaning its end time is now fixed) */
128 private volatile boolean fIsOnDisk
;
130 /* Vector containing all the intervals contained in this node */
131 private final List
<HTInterval
> fIntervals
;
133 /* Lock used to protect the accesses to intervals, nodeEnd and such */
134 private final ReentrantReadWriteLock fRwl
= new ReentrantReadWriteLock(false);
140 * Configuration of the History Tree
142 * The (unique) sequence number assigned to this particular node
143 * @param parentSeqNumber
144 * The sequence number of this node's parent node
146 * The earliest timestamp stored in this node
148 protected HTNode(HTConfig config
, int seqNumber
, int parentSeqNumber
, long start
) {
151 fSequenceNumber
= seqNumber
;
152 fParentSequenceNumber
= parentSeqNumber
;
154 fStringSectionOffset
= config
.getBlockSize();
155 fSizeOfIntervalSection
= 0;
157 fIntervals
= new ArrayList
<>();
161 * Reader factory method. Build a Node object (of the right type) by reading
162 * a block in the file.
165 * Configuration of the History Tree
167 * FileChannel to the history file, ALREADY SEEKED at the start
169 * @return The node object
170 * @throws IOException
171 * If there was an error reading from the file channel
173 public static final HTNode
readNode(HTConfig config
, FileChannel fc
)
175 HTNode newNode
= null;
178 ByteBuffer buffer
= ByteBuffer
.allocate(config
.getBlockSize());
179 buffer
.order(ByteOrder
.LITTLE_ENDIAN
);
181 res
= fc
.read(buffer
);
182 assert (res
== config
.getBlockSize());
185 /* Read the common header part */
186 byte typeByte
= buffer
.get();
187 NodeType type
= NodeType
.fromByte(typeByte
);
188 long start
= buffer
.getLong();
189 long end
= buffer
.getLong();
190 int seqNb
= buffer
.getInt();
191 int parentSeqNb
= buffer
.getInt();
192 int intervalCount
= buffer
.getInt();
193 int stringSectionOffset
= buffer
.getInt();
194 buffer
.get(); // TODO Used to be "isDone", to be removed from the header
196 /* Now the rest of the header depends on the node type */
200 newNode
= new CoreNode(config
, seqNb
, parentSeqNb
, start
);
201 newNode
.readSpecificHeader(buffer
);
206 newNode
= new LeafNode(config
, seqNb
, parentSeqNb
, start
);
207 newNode
.readSpecificHeader(buffer
);
211 /* Unrecognized node type */
212 throw new IOException();
216 * At this point, we should be done reading the header and 'buffer'
217 * should only have the intervals left
219 for (i
= 0; i
< intervalCount
; i
++) {
220 HTInterval interval
= HTInterval
.readFrom(buffer
);
221 newNode
.fIntervals
.add(interval
);
222 newNode
.fSizeOfIntervalSection
+= HTInterval
.DATA_ENTRY_SIZE
;
225 /* Assign the node's other information we have read previously */
226 newNode
.fNodeEnd
= end
;
227 newNode
.fStringSectionOffset
= stringSectionOffset
;
228 newNode
.fIsOnDisk
= true;
234 * Write this node to the given file channel.
237 * The file channel to write to (should be sought to be correct
239 * @throws IOException
240 * If there was an error writing
242 public final void writeSelf(FileChannel fc
) throws IOException
{
244 * Yes, we are taking the *read* lock here, because we are reading the
245 * information in the node to write it to disk.
247 fRwl
.readLock().lock();
249 final int blockSize
= fConfig
.getBlockSize();
250 int curStringsEntryEndPos
= blockSize
;
252 ByteBuffer buffer
= ByteBuffer
.allocate(blockSize
);
253 buffer
.order(ByteOrder
.LITTLE_ENDIAN
);
256 /* Write the common header part */
257 buffer
.put(getNodeType().toByte());
258 buffer
.putLong(fNodeStart
);
259 buffer
.putLong(fNodeEnd
);
260 buffer
.putInt(fSequenceNumber
);
261 buffer
.putInt(fParentSequenceNumber
);
262 buffer
.putInt(fIntervals
.size());
263 buffer
.putInt(fStringSectionOffset
);
264 buffer
.put((byte) 1); // TODO Used to be "isDone", to be removed from header
266 /* Now call the inner method to write the specific header part */
267 writeSpecificHeader(buffer
);
269 /* Back to us, we write the intervals */
270 for (HTInterval interval
: fIntervals
) {
271 int size
= interval
.writeInterval(buffer
, curStringsEntryEndPos
);
272 curStringsEntryEndPos
-= size
;
276 * Write padding between the end of the Data section and the start
277 * of the Strings section (needed to fill the node in case there is
278 * no Strings section)
280 while (buffer
.position() < fStringSectionOffset
) {
281 buffer
.put((byte) 0);
285 * If the offsets were right, the size of the Strings section should
286 * be == to the expected size
288 assert (curStringsEntryEndPos
== fStringSectionOffset
);
290 /* Finally, write everything in the Buffer to disk */
292 // if we don't do this, flip() will lose what's after.
293 buffer
.position(blockSize
);
296 int res
= fc
.write(buffer
);
297 assert (res
== blockSize
);
300 fRwl
.readLock().unlock();
305 // ------------------------------------------------------------------------
307 // ------------------------------------------------------------------------
310 * Retrieve the history tree configuration used for this node.
312 * @return The history tree config
314 protected HTConfig
getConfig() {
319 * Get the start time of this node.
321 * @return The start time of this node
323 public long getNodeStart() {
328 * Get the end time of this node.
330 * @return The end time of this node
332 public long getNodeEnd() {
340 * Get the sequence number of this node.
342 * @return The sequence number of this node
344 public int getSequenceNumber() {
345 return fSequenceNumber
;
349 * Get the sequence number of this node's parent.
351 * @return The parent sequence number
353 public int getParentSequenceNumber() {
354 return fParentSequenceNumber
;
358 * Change this node's parent. Used when we create a new root node for
362 * The sequence number of the node that is the new parent
364 public void setParentSequenceNumber(int newParent
) {
365 fParentSequenceNumber
= newParent
;
369 * Return if this node is "done" (full and written to disk).
371 * @return If this node is done or not
373 public boolean isOnDisk() {
378 * Add an interval to this node
381 * Interval to add to this node
383 public void addInterval(HTInterval newInterval
) {
384 fRwl
.writeLock().lock();
386 /* Just in case, should be checked before even calling this function */
387 assert (newInterval
.getIntervalSize() <= getNodeFreeSpace());
389 /* Find the insert position to keep the list sorted */
390 int index
= fIntervals
.size();
391 while (index
> 0 && newInterval
.compareTo(fIntervals
.get(index
- 1)) < 0) {
395 fIntervals
.add(index
, newInterval
);
396 fSizeOfIntervalSection
+= HTInterval
.DATA_ENTRY_SIZE
;
398 /* Update the in-node offset "pointer" */
399 fStringSectionOffset
-= (newInterval
.getStringsEntrySize());
401 fRwl
.writeLock().unlock();
406 * We've received word from the containerTree that newest nodes now exist to
407 * our right. (Puts isDone = true and sets the endtime)
410 * The nodeEnd time that the node will have
412 public void closeThisNode(long endtime
) {
413 fRwl
.writeLock().lock();
415 assert (endtime
>= fNodeStart
);
417 if (!fIntervals
.isEmpty()) {
419 * Make sure there are no intervals in this node with their
420 * EndTime > the one requested. Only need to check the last one
421 * since they are sorted
423 assert (endtime
>= fIntervals
.get(fIntervals
.size() - 1).getEndTime());
428 fRwl
.writeLock().unlock();
433 * The method to fill up the stateInfo (passed on from the Current State
434 * Tree when it does a query on the SHT). We'll replace the data in that
435 * vector with whatever relevant we can find from this node
438 * The same stateInfo that comes from SHT's doQuery()
440 * The timestamp for which the query is for. Only return
441 * intervals that intersect t.
442 * @throws TimeRangeException
445 public void writeInfoFromNode(List
<ITmfStateInterval
> stateInfo
, long t
)
446 throws TimeRangeException
{
447 /* This is from a state system query, we are "reading" this node */
448 fRwl
.readLock().lock();
450 for (int i
= getStartIndexFor(t
); i
< fIntervals
.size(); i
++) {
452 * Now we only have to compare the Start times, since we now the
453 * End times necessarily fit.
455 * Second condition is to ignore new attributes that might have
456 * been created after stateInfo was instantiated (they would be
459 ITmfStateInterval interval
= fIntervals
.get(i
);
460 if (interval
.getStartTime() <= t
&&
461 interval
.getAttribute() < stateInfo
.size()) {
462 stateInfo
.set(interval
.getAttribute(), interval
);
466 fRwl
.readLock().unlock();
471 * Get a single Interval from the information in this node If the
472 * key/timestamp pair cannot be found, we return null.
475 * The attribute quark to look for
478 * @return The Interval containing the information we want, or null if it
480 * @throws TimeRangeException
483 public HTInterval
getRelevantInterval(int key
, long t
) throws TimeRangeException
{
484 fRwl
.readLock().lock();
486 for (int i
= getStartIndexFor(t
); i
< fIntervals
.size(); i
++) {
487 HTInterval curInterval
= fIntervals
.get(i
);
488 if (curInterval
.getAttribute() == key
489 && curInterval
.getStartTime() <= t
490 && curInterval
.getEndTime() >= t
) {
495 /* We didn't find the relevant information in this node */
499 fRwl
.readLock().unlock();
503 private int getStartIndexFor(long t
) throws TimeRangeException
{
504 /* Should only be called by methods with the readLock taken */
506 if (fIntervals
.isEmpty()) {
510 * Since the intervals are sorted by end time, we can skip all the ones
511 * at the beginning whose end times are smaller than 't'. Java does
512 * provides a .binarySearch method, but its API is quite weird...
514 HTInterval dummy
= new HTInterval(0, t
, 0, TmfStateValue
.nullValue());
515 int index
= Collections
.binarySearch(fIntervals
, dummy
);
519 * .binarySearch returns a negative number if the exact value was
520 * not found. Here we just want to know where to start searching, we
521 * don't care if the value is exact or not.
527 /* Sometimes binarySearch yields weird stuff... */
531 if (index
>= fIntervals
.size()) {
532 index
= fIntervals
.size() - 1;
536 * Another API quirkiness, the returned index is the one of the *last*
537 * element of a series of equal endtimes, which happens sometimes. We
538 * want the *first* element of such a series, to read through them
542 && fIntervals
.get(index
- 1).compareTo(fIntervals
.get(index
)) == 0) {
550 * Return the total header size of this node (will depend on the node type).
552 * @return The total header size
554 public final int getTotalHeaderSize() {
555 return COMMON_HEADER_SIZE
+ getSpecificHeaderSize();
559 * @return The offset, within the node, where the Data section ends
561 private int getDataSectionEndOffset() {
562 return getTotalHeaderSize() + fSizeOfIntervalSection
;
566 * Returns the free space in the node, which is simply put, the
567 * stringSectionOffset - dataSectionOffset
569 * @return The amount of free space in the node (in bytes)
571 public int getNodeFreeSpace() {
572 fRwl
.readLock().lock();
573 int ret
= fStringSectionOffset
- getDataSectionEndOffset();
574 fRwl
.readLock().unlock();
580 * Returns the current space utilization of this node, as a percentage.
581 * (used space / total usable space, which excludes the header)
583 * @return The percentage (value between 0 and 100) of space utilization in
586 public long getNodeUsagePercent() {
587 fRwl
.readLock().lock();
589 final int blockSize
= fConfig
.getBlockSize();
590 float freePercent
= (float) getNodeFreeSpace()
591 / (float) (blockSize
- getTotalHeaderSize())
593 return (long) (100L - freePercent
);
596 fRwl
.readLock().unlock();
601 * @name Debugging functions
604 @SuppressWarnings("nls")
606 public String
toString() {
607 /* Only used for debugging, shouldn't be externalized */
608 StringBuffer buf
= new StringBuffer("Node #" + fSequenceNumber
+ ", ");
609 buf
.append(toStringSpecific());
610 buf
.append(fIntervals
.size() + " intervals (" + getNodeUsagePercent()
613 buf
.append("[" + fNodeStart
+ " - ");
615 buf
= buf
.append("" + fNodeEnd
+ "]");
617 buf
= buf
.append("...]");
619 return buf
.toString();
623 * Debugging function that prints out the contents of this node
626 * PrintWriter in which we will print the debug output
628 @SuppressWarnings("nls")
629 public void debugPrintIntervals(PrintWriter writer
) {
630 /* Only used for debugging, shouldn't be externalized */
631 writer
.println("Node #" + fSequenceNumber
+ ":");
633 /* Array of children */
634 if (getNodeType() == NodeType
.CORE
) { /* Only Core Nodes can have children */
635 CoreNode thisNode
= (CoreNode
) this;
636 writer
.print(" " + thisNode
.getNbChildren() + " children");
637 if (thisNode
.getNbChildren() >= 1) {
638 writer
.print(": [ " + thisNode
.getChild(0));
639 for (int i
= 1; i
< thisNode
.getNbChildren(); i
++) {
640 writer
.print(", " + thisNode
.getChild(i
));
647 /* List of intervals in the node */
648 writer
.println(" Intervals contained:");
649 for (int i
= 0; i
< fIntervals
.size(); i
++) {
650 writer
.println(fIntervals
.get(i
).toString());
652 writer
.println('\n');
655 // ------------------------------------------------------------------------
657 // ------------------------------------------------------------------------
660 * Get the byte value representing the node type.
662 * @return The node type
664 public abstract NodeType
getNodeType();
667 * Return the specific header size of this node. This means the size
668 * occupied by the type-specific section of the header (not counting the
671 * @return The specific header size
673 protected abstract int getSpecificHeaderSize();
676 * Read the type-specific part of the node header from a byte buffer.
679 * The byte buffer to read from. It should be already positioned
682 protected abstract void readSpecificHeader(ByteBuffer buffer
);
685 * Write the type-specific part of the header in a byte buffer.
688 * The buffer to write to. It should already be at the correct
691 protected abstract void writeSpecificHeader(ByteBuffer buffer
);
694 * Node-type-specific toString method. Used for debugging.
696 * @return A string representing the node
698 protected abstract String
toStringSpecific();