tikhomirov@10: /*
tikhomirov@530:  * Copyright (c) 2010-2013 TMate Software Ltd
tikhomirov@74:  *  
tikhomirov@74:  * This program is free software; you can redistribute it and/or modify
tikhomirov@74:  * it under the terms of the GNU General Public License as published by
tikhomirov@74:  * the Free Software Foundation; version 2 of the License.
tikhomirov@74:  *
tikhomirov@74:  * This program is distributed in the hope that it will be useful,
tikhomirov@74:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@74:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@74:  * GNU General Public License for more details.
tikhomirov@74:  *
tikhomirov@74:  * For information on how to redistribute this software under
tikhomirov@74:  * the terms of a license other than GNU General Public License
tikhomirov@102:  * contact TMate Software at support@hg4j.com
tikhomirov@0:  */
tikhomirov@77: package org.tmatesoft.hg.internal;
tikhomirov@0: 
tikhomirov@80: import static org.tmatesoft.hg.repo.HgRepository.BAD_REVISION;
tikhomirov@74: import static org.tmatesoft.hg.repo.HgRepository.TIP;
tikhomirov@530: import static org.tmatesoft.hg.internal.Internals.REVLOGV1_RECORD_SIZE;
tikhomirov@5: 
tikhomirov@3: import java.io.File;
tikhomirov@2: import java.io.IOException;
tikhomirov@593: import java.lang.ref.Reference;
tikhomirov@593: import java.lang.ref.ReferenceQueue;
tikhomirov@593: import java.lang.ref.SoftReference;
tikhomirov@607: import java.util.ArrayList;
tikhomirov@607: import java.util.List;
tikhomirov@263: import java.util.zip.Inflater;
tikhomirov@0: 
tikhomirov@74: import org.tmatesoft.hg.core.Nodeid;
tikhomirov@300: import org.tmatesoft.hg.repo.HgInternals;
tikhomirov@423: import org.tmatesoft.hg.repo.HgInvalidControlFileException;
tikhomirov@423: import org.tmatesoft.hg.repo.HgInvalidRevisionException;
tikhomirov@423: import org.tmatesoft.hg.repo.HgInvalidStateException;
tikhomirov@80: import org.tmatesoft.hg.repo.HgRepository;
tikhomirov@520: import org.tmatesoft.hg.util.Adaptable;
tikhomirov@74: 
tikhomirov@10: 
tikhomirov@0: /**
tikhomirov@0:  * ? Single RevlogStream per file per repository with accessor to record access session (e.g. with back/forward operations), 
tikhomirov@198:  * or numerous RevlogStream with separate representation of the underlying data (cached, lazy ChunkStream)?
tikhomirov@74:  * 
tikhomirov@0:  * @see http://mercurial.selenic.com/wiki/Revlog
tikhomirov@0:  * @see http://mercurial.selenic.com/wiki/RevlogNG
tikhomirov@74:  *
tikhomirov@74:  * @author Artem Tikhomirov
tikhomirov@74:  * @author TMate Software Ltd.
tikhomirov@0:  */
tikhomirov@0: public class RevlogStream {
tikhomirov@2: 
tikhomirov@608: 	static final int INLINEDATA = 1 << 16;
tikhomirov@608: 
tikhomirov@198: 	/*
tikhomirov@198: 	 * makes sense for index with inline data only - actual offset of the record in the .i file (record entry + revision * record size))
tikhomirov@198: 	 * 
tikhomirov@198: 	 * long[] in fact (there are 8-bytes field in the revlog)
tikhomirov@198: 	 * However, (a) DataAccess currently doesn't operate with long seek/length
tikhomirov@198: 	 * and, of greater significance, (b) files with inlined data are designated for smaller files,  
tikhomirov@198: 	 * guess, about 130 Kb, and offset there won't ever break int capacity
tikhomirov@198: 	 */
tikhomirov@198: 	private int[] indexRecordOffset;  
tikhomirov@198: 	private int[] baseRevisions;
tikhomirov@2: 	private boolean inline = false;
tikhomirov@3: 	private final File indexFile;
tikhomirov@396: 	private File dataFile;
tikhomirov@608: 	private final Internals repo;
tikhomirov@593: 	// keeps last complete revision we've read. Note, this cached revision doesn't help
tikhomirov@593: 	// for subsequent #iterate() calls with the same revision (Inspector needs more data than 
tikhomirov@593: 	// we currently cache here, perhaps, we shall cache everything it wants to cover same 
tikhomirov@593: 	// revision case as well). Now this helps when second #iterate() call is for a revision greater
tikhomirov@593: 	// than one from the first call, and both revisions got same base rev. It's often the case when
tikhomirov@593: 	// parents/children are analyzed.
tikhomirov@593: 	private SoftReference<CachedRevision> lastRevisionRead;
tikhomirov@593: 	private final ReferenceQueue<CachedRevision> lastRevisionQueue = new ReferenceQueue<CachedRevision>();
tikhomirov@607: 	//
tikhomirov@607: 	private final RevlogChangeMonitor changeTracker;
tikhomirov@607: 	private List<Observer> observers;
tikhomirov@607: 	private boolean shallDropDerivedCaches = false;
tikhomirov@3: 
tikhomirov@608: 	public RevlogStream(Internals hgRepo, File indexFile) {
tikhomirov@608: 		repo = hgRepo;
tikhomirov@3: 		this.indexFile = indexFile;
tikhomirov@608: 		changeTracker = repo.getRevlogTracker(indexFile);
tikhomirov@3: 	}
tikhomirov@2: 
tikhomirov@606: 	/**
tikhomirov@606: 	 * @param shortRead pass <code>true</code> to indicate intention to read few revisions only (as opposed to reading most of/complete revlog)
tikhomirov@606: 	 * @return never <code>null</code>, empty {@link DataAccess} if no stream is available
tikhomirov@606: 	 */
tikhomirov@606: 	/*package*/ DataAccess getIndexStream(boolean shortRead) {
tikhomirov@606: 		// shortRead hint helps  to avoid mmap files when only 
tikhomirov@606: 		// few bytes are to be read (i.e. #dataLength())
tikhomirov@608: 		DataAccessProvider dataAccess = repo.getDataAccess();
tikhomirov@606: 		return dataAccess.createReader(indexFile, shortRead);
tikhomirov@0: 	}
tikhomirov@0: 
tikhomirov@9: 	/*package*/ DataAccess getDataStream() {
tikhomirov@608: 		DataAccessProvider dataAccess = repo.getDataAccess();
tikhomirov@606: 		return dataAccess.createReader(getDataFile(), false);
tikhomirov@534: 	}
tikhomirov@534: 	
tikhomirov@534: 	/*package*/ DataSerializer getIndexStreamWriter() {
tikhomirov@608: 		DataAccessProvider dataAccess = repo.getDataAccess();
tikhomirov@534: 		return dataAccess.createWriter(indexFile, true);
tikhomirov@534: 	}
tikhomirov@534: 	
tikhomirov@534: 	/*package*/ DataSerializer getDataStreamWriter() {
tikhomirov@608: 		DataAccessProvider dataAccess = repo.getDataAccess();
tikhomirov@534: 		return dataAccess.createWriter(getDataFile(), true);
tikhomirov@9: 	}
tikhomirov@9: 	
tikhomirov@396: 	/**
tikhomirov@396: 	 * Constructs file object that corresponds to .d revlog counterpart. 
tikhomirov@396: 	 * Note, it's caller responsibility to ensure this file makes any sense (i.e. check {@link #inline} attribute)
tikhomirov@396: 	 */
tikhomirov@396: 	private File getDataFile() {
tikhomirov@396: 		if (dataFile == null) {
tikhomirov@396: 			final String indexName = indexFile.getName();
tikhomirov@396: 			dataFile = new File(indexFile.getParentFile(), indexName.substring(0, indexName.length() - 1) + "d");
tikhomirov@396: 		}
tikhomirov@396: 		return dataFile;
tikhomirov@396: 	}
tikhomirov@396: 	
tikhomirov@396: 	// initialize exception with the file where revlog structure information comes from
tikhomirov@396: 	public HgInvalidControlFileException initWithIndexFile(HgInvalidControlFileException ex) {
tikhomirov@396: 		return ex.setFile(indexFile);
tikhomirov@396: 	}
tikhomirov@396: 
tikhomirov@396: 	// initialize exception with the file where revlog data comes from
tikhomirov@396: 	public HgInvalidControlFileException initWithDataFile(HgInvalidControlFileException ex) {
tikhomirov@396: 		// exceptions are usually raised after read attepmt, hence inline shall be initialized
tikhomirov@396: 		// although honest approach is to call #initOutline() first
tikhomirov@396: 		return ex.setFile(inline ? indexFile : getDataFile());
tikhomirov@396: 	}
tikhomirov@534: 	
tikhomirov@534: 	/*package-private*/String getDataFileName() {
tikhomirov@534: 		// XXX a temporary solution to provide more info to fill in exceptions other than 
tikhomirov@534: 		// HgInvalidControlFileException (those benefit from initWith* methods above)
tikhomirov@534: 		//
tikhomirov@534: 		// Besides, since RevlogStream represents both revlogs with user data (those with WC representative and 
tikhomirov@534: 		// system data under store/data) and system-only revlogs (like changelog and manifest), there's no
tikhomirov@534: 		// easy way to supply human-friendly name of the active file (independent from whether it's index of data)
tikhomirov@534: 		return inline ? indexFile.getPath() : getDataFile().getPath();
tikhomirov@534: 	}
tikhomirov@396: 
tikhomirov@534: 	public boolean isInlineData() {
tikhomirov@534: 		initOutline();
tikhomirov@534: 		return inline;
tikhomirov@534: 	}
tikhomirov@396: 	
tikhomirov@2: 	public int revisionCount() {
tikhomirov@2: 		initOutline();
tikhomirov@198: 		return baseRevisions.length;
tikhomirov@2: 	}
tikhomirov@22: 	
tikhomirov@295: 	/**
tikhomirov@354: 	 * @throws HgInvalidControlFileException if attempt to read index file failed
tikhomirov@354: 	 * @throws HgInvalidRevisionException if revisionIndex argument doesn't represent a valid record in the revlog
tikhomirov@295: 	 */
tikhomirov@354: 	public int dataLength(int revisionIndex) throws HgInvalidControlFileException, HgInvalidRevisionException {
tikhomirov@22: 		// XXX in fact, use of iterate() instead of this implementation may be quite reasonable.
tikhomirov@22: 		//
tikhomirov@354: 		revisionIndex = checkRevisionIndex(revisionIndex);
tikhomirov@606: 		DataAccess daIndex = getIndexStream(true);
tikhomirov@22: 		try {
tikhomirov@354: 			int recordOffset = getIndexOffsetInt(revisionIndex);
tikhomirov@22: 			daIndex.seek(recordOffset + 12); // 6+2+4
tikhomirov@22: 			int actualLen = daIndex.readInt();
tikhomirov@22: 			return actualLen; 
tikhomirov@22: 		} catch (IOException ex) {
tikhomirov@440: 			throw new HgInvalidControlFileException(null, ex, indexFile).setRevisionIndex(revisionIndex);
tikhomirov@22: 		} finally {
tikhomirov@22: 			daIndex.done();
tikhomirov@22: 		}
tikhomirov@22: 	}
tikhomirov@22: 	
tikhomirov@295: 	/**
tikhomirov@354: 	 * Read nodeid at given index
tikhomirov@354: 	 * 
tikhomirov@354: 	 * @throws HgInvalidControlFileException if attempt to read index file failed
tikhomirov@354: 	 * @throws HgInvalidRevisionException if revisionIndex argument doesn't represent a valid record in the revlog
tikhomirov@295: 	 */
tikhomirov@354: 	public byte[] nodeid(int revisionIndex) throws HgInvalidControlFileException, HgInvalidRevisionException {
tikhomirov@354: 		revisionIndex = checkRevisionIndex(revisionIndex);
tikhomirov@606: 		DataAccess daIndex = getIndexStream(true);
tikhomirov@80: 		try {
tikhomirov@354: 			int recordOffset = getIndexOffsetInt(revisionIndex);
tikhomirov@80: 			daIndex.seek(recordOffset + 32);
tikhomirov@80: 			byte[] rv = new byte[20];
tikhomirov@80: 			daIndex.readBytes(rv, 0, 20);
tikhomirov@80: 			return rv;
tikhomirov@80: 		} catch (IOException ex) {
tikhomirov@440: 			throw new HgInvalidControlFileException("Revision lookup failed", ex, indexFile).setRevisionIndex(revisionIndex);
tikhomirov@80: 		} finally {
tikhomirov@88: 			daIndex.done();
tikhomirov@88: 		}
tikhomirov@88: 	}
tikhomirov@295: 
tikhomirov@295: 	/**
tikhomirov@295: 	 * Get link field from the index record.
tikhomirov@354: 	 * 
tikhomirov@354: 	 * @throws HgInvalidControlFileException if attempt to read index file failed
tikhomirov@354: 	 * @throws HgInvalidRevisionException if revisionIndex argument doesn't represent a valid record in the revlog
tikhomirov@295: 	 */
tikhomirov@354: 	public int linkRevision(int revisionIndex) throws HgInvalidControlFileException, HgInvalidRevisionException {
tikhomirov@354: 		revisionIndex = checkRevisionIndex(revisionIndex);
tikhomirov@606: 		DataAccess daIndex = getIndexStream(true);
tikhomirov@88: 		try {
tikhomirov@354: 			int recordOffset = getIndexOffsetInt(revisionIndex);
tikhomirov@88: 			daIndex.seek(recordOffset + 20);
tikhomirov@88: 			int linkRev = daIndex.readInt();
tikhomirov@88: 			return linkRev;
tikhomirov@88: 		} catch (IOException ex) {
tikhomirov@440: 			throw new HgInvalidControlFileException("Linked revision lookup failed", ex, indexFile).setRevisionIndex(revisionIndex);
tikhomirov@88: 		} finally {
tikhomirov@88: 			daIndex.done();
tikhomirov@80: 		}
tikhomirov@80: 	}
tikhomirov@80: 	
tikhomirov@585: 	/**
tikhomirov@585: 	 * Extract base revision field from the revlog
tikhomirov@585: 	 * 
tikhomirov@585: 	 * @throws HgInvalidControlFileException if attempt to read index file failed
tikhomirov@585: 	 * @throws HgInvalidRevisionException if revisionIndex argument doesn't represent a valid record in the revlog
tikhomirov@585: 	 */
tikhomirov@585: 	public int baseRevision(int revisionIndex) throws HgInvalidControlFileException, HgInvalidRevisionException {
tikhomirov@585: 		revisionIndex = checkRevisionIndex(revisionIndex);
tikhomirov@585: 		return getBaseRevision(revisionIndex);
tikhomirov@585: 	}
tikhomirov@585: 	
tikhomirov@49: 	// Perhaps, RevlogStream should be limited to use of plain int revisions for access,
tikhomirov@49: 	// while Nodeids should be kept on the level up, in Revlog. Guess, Revlog better keep
tikhomirov@49: 	// map of nodeids, and once this comes true, we may get rid of this method.
tikhomirov@80: 	// Unlike its counterpart, {@link Revlog#getLocalRevisionNumber()}, doesn't fail with exception if node not found,
tikhomirov@80: 	/**
tikhomirov@80: 	 * @return integer in [0..revisionCount()) or {@link HgRepository#BAD_REVISION} if not found
tikhomirov@354: 	 * @throws HgInvalidControlFileException if attempt to read index file failed
tikhomirov@80: 	 */
tikhomirov@367: 	public int findRevisionIndex(Nodeid nodeid) throws HgInvalidControlFileException {
tikhomirov@22: 		// XXX this one may be implemented with iterate() once there's mechanism to stop iterations
tikhomirov@22: 		final int indexSize = revisionCount();
tikhomirov@606: 		DataAccess daIndex = getIndexStream(false);
tikhomirov@22: 		try {
tikhomirov@24: 			byte[] nodeidBuf = new byte[20];
tikhomirov@22: 			for (int i = 0; i < indexSize; i++) {
tikhomirov@22: 				daIndex.skip(8);
tikhomirov@22: 				int compressedLen = daIndex.readInt();
tikhomirov@22: 				daIndex.skip(20);
tikhomirov@24: 				daIndex.readBytes(nodeidBuf, 0, 20);
tikhomirov@24: 				if (nodeid.equalsTo(nodeidBuf)) {
tikhomirov@22: 					return i;
tikhomirov@22: 				}
tikhomirov@22: 				daIndex.skip(inline ? 12 + compressedLen : 12);
tikhomirov@22: 			}
tikhomirov@22: 		} catch (IOException ex) {
tikhomirov@440: 			throw new HgInvalidControlFileException("Revision lookup failed", ex, indexFile).setRevision(nodeid);
tikhomirov@22: 		} finally {
tikhomirov@22: 			daIndex.done();
tikhomirov@22: 		}
tikhomirov@80: 		return BAD_REVISION;
tikhomirov@22: 	}
tikhomirov@538: 	
tikhomirov@539: 	/**
tikhomirov@539: 	 * @return value suitable for the corresponding field in the new revision's header, not physical offset in the file 
tikhomirov@539: 	 * (which is different in case of inline revlogs)
tikhomirov@539: 	 */
tikhomirov@538: 	public long newEntryOffset() {
tikhomirov@538: 		if (revisionCount() == 0) {
tikhomirov@538: 			return 0;
tikhomirov@538: 		}
tikhomirov@606: 		DataAccess daIndex = getIndexStream(true);
tikhomirov@538: 		int lastRev = revisionCount() - 1;
tikhomirov@538: 		try {
tikhomirov@538: 			int recordOffset = getIndexOffsetInt(lastRev);
tikhomirov@538: 			daIndex.seek(recordOffset);
tikhomirov@538: 			long value = daIndex.readLong();
tikhomirov@538: 			value = value >>> 16;
tikhomirov@538: 			int compressedLen = daIndex.readInt();
tikhomirov@538: 			return lastRev == 0 ? compressedLen : value + compressedLen;
tikhomirov@538: 		} catch (IOException ex) {
tikhomirov@538: 			throw new HgInvalidControlFileException("Linked revision lookup failed", ex, indexFile).setRevisionIndex(lastRev);
tikhomirov@538: 		} finally {
tikhomirov@538: 			daIndex.done();
tikhomirov@538: 		}
tikhomirov@538: 	}
tikhomirov@538: 
tikhomirov@3: 	// should be possible to use TIP, ALL, or -1, -2, -n notation of Hg
tikhomirov@3: 	// ? boolean needsNodeid
tikhomirov@423: 	public void iterate(int start, int end, boolean needData, Inspector inspector) throws HgInvalidRevisionException, HgInvalidControlFileException {
tikhomirov@2: 		initOutline();
tikhomirov@198: 		final int indexSize = revisionCount();
tikhomirov@3: 		if (indexSize == 0) {
tikhomirov@3: 			return;
tikhomirov@3: 		}
tikhomirov@5: 		if (end == TIP) {
tikhomirov@3: 			end = indexSize - 1;
tikhomirov@3: 		}
tikhomirov@5: 		if (start == TIP) {
tikhomirov@5: 			start = indexSize - 1;
tikhomirov@5: 		}
tikhomirov@300: 		HgInternals.checkRevlogRange(start, end, indexSize-1);
tikhomirov@2: 		// XXX may cache [start .. end] from index with a single read (pre-read)
tikhomirov@2: 		
tikhomirov@608: 		ReaderN1 r = new ReaderN1(needData, inspector, repo.shallMergePatches());
tikhomirov@2: 		try {
tikhomirov@593: 			r.start(end - start + 1, getLastRevisionRead());
tikhomirov@242: 			r.range(start, end);
tikhomirov@242: 		} catch (IOException ex) {
tikhomirov@366: 			throw new HgInvalidControlFileException(String.format("Failed reading [%d..%d]", start, end), ex, indexFile);
tikhomirov@242: 		} finally {
tikhomirov@593: 			CachedRevision cr = r.finish();
tikhomirov@593: 			setLastRevisionRead(cr);
tikhomirov@242: 		}
tikhomirov@242: 	}
tikhomirov@242: 	
tikhomirov@242: 	/**
tikhomirov@242: 	 * Effective alternative to {@link #iterate(int, int, boolean, Inspector) batch read}, when only few selected 
tikhomirov@242: 	 * revisions are of interest.
tikhomirov@242: 	 * @param sortedRevisions revisions to walk, in ascending order.
tikhomirov@242: 	 * @param needData whether inspector needs access to header only
tikhomirov@242: 	 * @param inspector callback to process entries
tikhomirov@242: 	 */
tikhomirov@366: 	public void iterate(int[] sortedRevisions, boolean needData, Inspector inspector) throws HgInvalidRevisionException, HgInvalidControlFileException /*REVISIT - too general exception*/ {
tikhomirov@242: 		final int indexSize = revisionCount();
tikhomirov@242: 		if (indexSize == 0 || sortedRevisions.length == 0) {
tikhomirov@242: 			return;
tikhomirov@242: 		}
tikhomirov@347: 		if (sortedRevisions[0] > indexSize) {
tikhomirov@347: 			throw new HgInvalidRevisionException(String.format("Can't iterate [%d, %d] in range [0..%d]", sortedRevisions[0], sortedRevisions[sortedRevisions.length - 1], indexSize), null, sortedRevisions[0]);
tikhomirov@347: 		}
tikhomirov@347: 		if (sortedRevisions[sortedRevisions.length - 1] > indexSize) {
tikhomirov@347: 			throw new HgInvalidRevisionException(String.format("Can't iterate [%d, %d] in range [0..%d]", sortedRevisions[0], sortedRevisions[sortedRevisions.length - 1], indexSize), null, sortedRevisions[sortedRevisions.length - 1]);
tikhomirov@242: 		}
tikhomirov@242: 
tikhomirov@608: 		ReaderN1 r = new ReaderN1(needData, inspector, repo.shallMergePatches());
tikhomirov@242: 		try {
tikhomirov@594: 			r.start(sortedRevisions.length, getLastRevisionRead());
tikhomirov@242: 			for (int i = 0; i < sortedRevisions.length; ) {
tikhomirov@242: 				int x = i;
tikhomirov@242: 				i++;
tikhomirov@242: 				while (i < sortedRevisions.length) {
tikhomirov@242: 					if (sortedRevisions[i] == sortedRevisions[i-1] + 1) {
tikhomirov@242: 						i++;
tikhomirov@2: 					} else {
tikhomirov@217: 						break;
tikhomirov@217: 					}
tikhomirov@217: 				}
tikhomirov@242: 				// commitRevisions[x..i-1] are sequential
tikhomirov@242: 				if (!r.range(sortedRevisions[x], sortedRevisions[i-1])) {
tikhomirov@242: 					return;
tikhomirov@51: 				}
tikhomirov@2: 			}
tikhomirov@2: 		} catch (IOException ex) {
tikhomirov@366: 			final int c = sortedRevisions.length;
tikhomirov@608: 			throw new HgInvalidControlFileException(String.format("Failed reading %d revisions in [%d; %d]", c, sortedRevisions[0], sortedRevisions[c-1]), ex, indexFile);
tikhomirov@3: 		} finally {
tikhomirov@593: 			CachedRevision cr = r.finish();
tikhomirov@593: 			setLastRevisionRead(cr);
tikhomirov@2: 		}
tikhomirov@2: 	}
tikhomirov@607: 	
tikhomirov@607: 	public void attach(Observer listener) {
tikhomirov@607: 		assert listener != null;
tikhomirov@607: 		if (observers == null) {
tikhomirov@607: 			observers = new ArrayList<Observer>(3);
tikhomirov@607: 		}
tikhomirov@607: 		observers.add(listener);
tikhomirov@607: 	}
tikhomirov@607: 	
tikhomirov@607: 	public void detach(Observer listener) {
tikhomirov@607: 		assert listener != null;
tikhomirov@607: 		if (observers != null) {
tikhomirov@607: 			observers.remove(listener);
tikhomirov@607: 		}
tikhomirov@607: 	}
tikhomirov@607: 	
tikhomirov@607: 	/*
tikhomirov@607: 	 * Note, this method IS NOT a replacement for Observer. It has to be invoked when the validity of any
tikhomirov@607: 	 * cache built using revision information is in doubt, but it provides reasonable value only till the
tikhomirov@607: 	 * first initOutline() to be invoked, i.e. in [change..revlog read operation] time frame. If your code
tikhomirov@607: 	 * accesses cached information without any prior explicit read operation, you shall consult this method
tikhomirov@607: 	 * if next read operation would in fact bring changed content.
tikhomirov@607: 	 * Observer is needed in addition to this method because any revlog read operation (e.g. Revlog#getLastRevision)
tikhomirov@607: 	 * would clear shallDropDerivedCaches(), and if code relies only on this method to clear its derived caches,
tikhomirov@607: 	 * it would miss the update.
tikhomirov@607: 	 */
tikhomirov@607: 	public boolean shallDropDerivedCaches() {
tikhomirov@607: 		if (shallDropDerivedCaches) {
tikhomirov@607: 			return shallDropDerivedCaches;
tikhomirov@607: 		}
tikhomirov@607: 		return shallDropDerivedCaches = changeTracker.hasChanged(indexFile);
tikhomirov@607: 	}
tikhomirov@198: 
tikhomirov@539: 	void revisionAdded(int revisionIndex, Nodeid revision, int baseRevisionIndex, long revisionOffset) throws HgInvalidControlFileException {
tikhomirov@607: 		shallDropDerivedCaches = true;
tikhomirov@539: 		if (!outlineCached()) {
tikhomirov@539: 			return;
tikhomirov@539: 		}
tikhomirov@539: 		if (baseRevisions.length != revisionIndex) {
tikhomirov@539: 			throw new HgInvalidControlFileException(String.format("New entry's index shall be %d, not %d", baseRevisions.length, revisionIndex), null, indexFile);
tikhomirov@539: 		}
tikhomirov@539: 		if (baseRevisionIndex < 0 || baseRevisionIndex > baseRevisions.length) {
tikhomirov@539: 			// baseRevisionIndex MAY be == to baseRevisions.length, it's when new revision is based on itself
tikhomirov@539: 			throw new HgInvalidControlFileException(String.format("Base revision index %d doesn't fit [0..%d] range", baseRevisionIndex, baseRevisions.length), null, indexFile);
tikhomirov@539: 		}
tikhomirov@539: 		assert revision != null;
tikhomirov@539: 		assert !revision.isNull();
tikhomirov@539: 		int[] baseRevisionsCopy = new int[baseRevisions.length + 1];
tikhomirov@539: 		System.arraycopy(baseRevisions, 0, baseRevisionsCopy, 0, baseRevisions.length);
tikhomirov@539: 		baseRevisionsCopy[baseRevisions.length] = baseRevisionIndex;
tikhomirov@539: 		baseRevisions = baseRevisionsCopy;
tikhomirov@539: 		if (inline && indexRecordOffset != null) {
tikhomirov@539: 			assert indexRecordOffset.length == revisionIndex;
tikhomirov@539: 			int[] indexRecordOffsetCopy = new int[indexRecordOffset.length + 1];
tikhomirov@559: 			System.arraycopy(indexRecordOffset, 0, indexRecordOffsetCopy, 0, indexRecordOffset.length);
tikhomirov@539: 			indexRecordOffsetCopy[indexRecordOffset.length] = offsetFieldToInlineFileOffset(revisionOffset, revisionIndex);
tikhomirov@539: 			indexRecordOffset = indexRecordOffsetCopy;
tikhomirov@539: 		}
tikhomirov@539: 	}
tikhomirov@539: 	
tikhomirov@198: 	private int getBaseRevision(int revision) {
tikhomirov@198: 		return baseRevisions[revision];
tikhomirov@198: 	}
tikhomirov@198: 
tikhomirov@198: 	/**
tikhomirov@354: 	 * @param revisionIndex shall be valid index, [0..baseRevisions.length-1]. 
tikhomirov@354: 	 * It's advised to use {@link #checkRevisionIndex(int)} to ensure argument is correct. 
tikhomirov@198: 	 * @return  offset of the revision's record in the index (.i) stream
tikhomirov@198: 	 */
tikhomirov@354: 	private int getIndexOffsetInt(int revisionIndex) {
tikhomirov@354: 		return inline ? indexRecordOffset[revisionIndex] : revisionIndex * REVLOGV1_RECORD_SIZE;
tikhomirov@354: 	}
tikhomirov@354: 	
tikhomirov@354: 	private int checkRevisionIndex(int revisionIndex) throws HgInvalidRevisionException {
tikhomirov@354: 		final int last = revisionCount() - 1;
tikhomirov@354: 		if (revisionIndex == TIP) {
tikhomirov@354: 			revisionIndex = last;
tikhomirov@354: 		}
tikhomirov@354: 		if (revisionIndex < 0 || revisionIndex > last) {
tikhomirov@354: 			throw new HgInvalidRevisionException(revisionIndex).setRevisionIndex(revisionIndex, 0, last);
tikhomirov@354: 		}
tikhomirov@354: 		return revisionIndex;
tikhomirov@198: 	}
tikhomirov@539: 	
tikhomirov@539: 	private boolean outlineCached() {
tikhomirov@539: 		return baseRevisions != null && baseRevisions.length > 0;
tikhomirov@539: 	}
tikhomirov@539: 	
tikhomirov@584: 	// translate 6-byte offset field value to physical file offset for inline revlogs
tikhomirov@539: 	// DOESN'T MAKE SENSE if revlog with data is separate
tikhomirov@539: 	private static int offsetFieldToInlineFileOffset(long offset, int recordIndex) throws HgInvalidStateException {
tikhomirov@539: 		int o = Internals.ltoi(offset);
tikhomirov@539: 		if (o != offset) {
tikhomirov@539: 			// just in case, can't happen, ever, unless HG (or some other bad tool) produces index file 
tikhomirov@539: 			// with inlined data of size greater than 2 Gb.
tikhomirov@539: 			throw new HgInvalidStateException("Data too big, offset didn't fit to sizeof(int)");
tikhomirov@539: 		}
tikhomirov@539: 		return o + REVLOGV1_RECORD_SIZE * recordIndex;
tikhomirov@539: 	}
tikhomirov@198: 
tikhomirov@607: 	// every access to index revlog goes after this method only.
tikhomirov@425: 	private void initOutline() throws HgInvalidControlFileException {
tikhomirov@607: 		// true to send out 'drop-your-caches' event after outline has been built
tikhomirov@607: 		final boolean notifyReload;
tikhomirov@539: 		if (outlineCached()) {
tikhomirov@607: 			if (!changeTracker.hasChanged(indexFile)) {
tikhomirov@607: 				return;
tikhomirov@607: 			}
tikhomirov@607: 			notifyReload = true;
tikhomirov@607: 		} else {
tikhomirov@607: 			// no cached outline - inital read, do not send any reload/invalidate notifications
tikhomirov@607: 			notifyReload = false;
tikhomirov@2: 		}
tikhomirov@607: 		changeTracker.touch(indexFile);
tikhomirov@606: 		DataAccess da = getIndexStream(false);
tikhomirov@2: 		try {
tikhomirov@202: 			if (da.isEmpty()) {
tikhomirov@202: 				// do not fail with exception if stream is empty, it's likely intentional
tikhomirov@202: 				baseRevisions = new int[0];
tikhomirov@539: 				// empty revlog, likely to be populated, indicate we start with a single file
tikhomirov@539: 				inline = true;
tikhomirov@202: 				return;
tikhomirov@202: 			}
tikhomirov@9: 			int versionField = da.readInt();
tikhomirov@170: 			da.readInt(); // just to skip next 4 bytes of offset + flags
tikhomirov@2: 			inline = (versionField & INLINEDATA) != 0;
tikhomirov@288: 			IntVector resBases, resOffsets = null;
tikhomirov@420: 			int entryCountGuess = Internals.ltoi(da.longLength() / REVLOGV1_RECORD_SIZE);
tikhomirov@288: 			if (inline) {
tikhomirov@288: 				entryCountGuess >>>= 2; // pure guess, assume useful data takes 3/4 of total space
tikhomirov@288: 				resOffsets = new IntVector(entryCountGuess, 5000);
tikhomirov@288: 			}
tikhomirov@288: 			resBases = new IntVector(entryCountGuess, 5000);
tikhomirov@288: 			
tikhomirov@2: 			long offset = 0; // first offset is always 0, thus Hg uses it for other purposes
tikhomirov@9: 			while(true) {
tikhomirov@9: 				int compressedLen = da.readInt();
tikhomirov@5: 				// 8+4 = 12 bytes total read here
tikhomirov@49: 				@SuppressWarnings("unused")
tikhomirov@9: 				int actualLen = da.readInt();
tikhomirov@9: 				int baseRevision = da.readInt();
tikhomirov@5: 				// 12 + 8 = 20 bytes read here
tikhomirov@2: //				int linkRevision = di.readInt();
tikhomirov@2: //				int parent1Revision = di.readInt();
tikhomirov@2: //				int parent2Revision = di.readInt();
tikhomirov@2: //				byte[] nodeid = new byte[32];
tikhomirov@198: 				resBases.add(baseRevision);
tikhomirov@2: 				if (inline) {
tikhomirov@539: 					int o = offsetFieldToInlineFileOffset(offset, resOffsets.size());
tikhomirov@539: 					resOffsets.add(o);
tikhomirov@9: 					da.skip(3*4 + 32 + compressedLen); // Check: 44 (skip) + 20 (read) = 64 (total RevlogNG record size)
tikhomirov@2: 				} else {
tikhomirov@9: 					da.skip(3*4 + 32);
tikhomirov@2: 				}
tikhomirov@10: 				if (da.isEmpty()) {
tikhomirov@9: 					// fine, done then
tikhomirov@288: 					baseRevisions = resBases.toArray(true);
tikhomirov@198: 					if (inline) {
tikhomirov@288: 						indexRecordOffset = resOffsets.toArray(true);
tikhomirov@198: 					}
tikhomirov@9: 					break;
tikhomirov@10: 				} else {
tikhomirov@10: 					// start reading next record
tikhomirov@10: 					long l = da.readLong();
tikhomirov@10: 					offset = l >>> 16;
tikhomirov@9: 				}
tikhomirov@2: 			}
tikhomirov@2: 		} catch (IOException ex) {
tikhomirov@423: 			throw new HgInvalidControlFileException("Failed to analyze revlog index", ex, indexFile);
tikhomirov@9: 		} finally {
tikhomirov@9: 			da.done();
tikhomirov@607: 			if (notifyReload && observers != null) {
tikhomirov@607: 				for (Observer l : observers) {
tikhomirov@607: 					l.reloaded(this);
tikhomirov@607: 				}
tikhomirov@607: 				shallDropDerivedCaches = false;
tikhomirov@607: 			}
tikhomirov@2: 		}
tikhomirov@3: 	}
tikhomirov@3: 	
tikhomirov@593: 	private CachedRevision getLastRevisionRead() {
tikhomirov@593: 		return lastRevisionRead == null ? null : lastRevisionRead.get();
tikhomirov@593: 	}
tikhomirov@593: 	
tikhomirov@593: 	private void setLastRevisionRead(CachedRevision cr) {
tikhomirov@593: 		// done() for lastRevisionRead.userData has been called by ReaderN1 once
tikhomirov@593: 		// it noticed unsuitable DataAccess.
tikhomirov@593: 		// Now, done() for any CachedRevision cleared by GC:
tikhomirov@593: 		for (Reference<? extends CachedRevision> r; (r = lastRevisionQueue.poll()) != null;) {
tikhomirov@593: 			CachedRevision toClean = r.get();
tikhomirov@593: 			if (toClean != null && toClean.userData != null) {
tikhomirov@593: 				toClean.userData.done();
tikhomirov@593: 			}
tikhomirov@593: 		}
tikhomirov@593: 		if (cr != null) {
tikhomirov@593: 			lastRevisionRead = new SoftReference<CachedRevision>(cr, lastRevisionQueue);
tikhomirov@593: 		} else {
tikhomirov@593: 			lastRevisionRead = null;
tikhomirov@593: 		}
tikhomirov@593: 	}
tikhomirov@593: 	
tikhomirov@593: 	final static class CachedRevision {
tikhomirov@593: 		final int revision;
tikhomirov@593: 		final DataAccess userData;
tikhomirov@593: 		
tikhomirov@593: 		public CachedRevision(int lastRevisionRead, DataAccess lastUserData) {
tikhomirov@593: 			revision = lastRevisionRead;
tikhomirov@593: 			userData = lastUserData;
tikhomirov@593: 		}
tikhomirov@593: 	}
tikhomirov@593: 
tikhomirov@242: 	/**
tikhomirov@242: 	 * operation with single file open/close and multiple diverse reads.
tikhomirov@366: 	 * XXX initOutline might need similar extraction to keep N1 format knowledge  
tikhomirov@242: 	 */
tikhomirov@584: 	final class ReaderN1 {
tikhomirov@242: 		private final Inspector inspector;
tikhomirov@242: 		private final boolean needData;
tikhomirov@584: 		private final boolean mergePatches;
tikhomirov@242: 		private DataAccess daIndex = null, daData = null;
tikhomirov@242: 		private Lifecycle.BasicCallback cb = null;
tikhomirov@520: 		private Lifecycle lifecycleListener = null;
tikhomirov@242: 		private int lastRevisionRead = BAD_REVISION;
tikhomirov@242: 		private DataAccess lastUserData;
tikhomirov@584: 		//
tikhomirov@584: 		// next are transient values, for range() use only
tikhomirov@584: 		private final Inflater inflater = new Inflater();
tikhomirov@584: 		// can share buffer between instances of InflaterDataAccess as I never read any two of them in parallel
tikhomirov@608: 		private final byte[] inflaterBuffer = new byte[10 * 1024]; // TODO [post-1.1] consider using DAP.DEFAULT_FILE_BUFFER
tikhomirov@584: 		private final byte[] nodeidBuf = new byte[20];
tikhomirov@584: 		// revlog record fields
tikhomirov@584: 		private long offset;
tikhomirov@584: 		@SuppressWarnings("unused")
tikhomirov@584: 		private int flags;
tikhomirov@584: 		private int compressedLen;
tikhomirov@584: 		private int actualLen;
tikhomirov@584: 		private int baseRevision;
tikhomirov@584: 		private int linkRevision;
tikhomirov@584: 		private int parent1Revision;
tikhomirov@584: 		private int parent2Revision;
tikhomirov@584: 		
tikhomirov@584: 		public ReaderN1(boolean dataRequested, Inspector insp, boolean usePatchMerge) {
tikhomirov@242: 			assert insp != null;
tikhomirov@584: 			needData = dataRequested;
tikhomirov@242: 			inspector = insp;
tikhomirov@584: 			mergePatches = usePatchMerge;
tikhomirov@242: 		}
tikhomirov@242: 		
tikhomirov@593: 		public void start(int totalWork, CachedRevision cachedRevision) {
tikhomirov@606: 			daIndex = getIndexStream(totalWork <= 10);
tikhomirov@242: 			if (needData && !inline) {
tikhomirov@242: 				daData = getDataStream();
tikhomirov@242: 			}
tikhomirov@520: 			lifecycleListener = Adaptable.Factory.getAdapter(inspector, Lifecycle.class, null);
tikhomirov@520: 			if (lifecycleListener != null) {
tikhomirov@242: 				cb = new Lifecycle.BasicCallback();
tikhomirov@520: 				lifecycleListener.start(totalWork, cb, cb);
tikhomirov@242: 			}
tikhomirov@593: 			if (needData && cachedRevision != null) {
tikhomirov@593: 				lastUserData = cachedRevision.userData;
tikhomirov@593: 				lastRevisionRead = cachedRevision.revision;
tikhomirov@593: 				assert lastUserData != null;
tikhomirov@593: 			}
tikhomirov@242: 		}
tikhomirov@242: 
tikhomirov@520: 		// invoked only once per instance
tikhomirov@593: 		public CachedRevision finish() {
tikhomirov@593: 			CachedRevision rv = null;
tikhomirov@242: 			if (lastUserData != null) {
tikhomirov@594: 				if (lastUserData instanceof ByteArrayDataAccess) {
tikhomirov@594: 					// it's safe to cache only in-memory revision texts,
tikhomirov@594: 					// if lastUserData is merely a filter over file stream,
tikhomirov@594: 					// we'd need to keep file open, and this is bad.
tikhomirov@594: 					// XXX perhaps, wrap any DataAccess.byteArray into
tikhomirov@594: 					// ByteArrayDataAccess?
tikhomirov@594: 					rv = new CachedRevision(lastRevisionRead, lastUserData);
tikhomirov@594: 				} else {
tikhomirov@594: 					lastUserData.done();
tikhomirov@594: 				}
tikhomirov@242: 				lastUserData = null;
tikhomirov@242: 			}
tikhomirov@520: 			if (lifecycleListener != null) {
tikhomirov@520: 				lifecycleListener.finish(cb);
tikhomirov@520: 				lifecycleListener = null;
tikhomirov@520: 				cb = null;
tikhomirov@520: 				
tikhomirov@242: 			}
tikhomirov@242: 			daIndex.done();
tikhomirov@242: 			if (daData != null) {
tikhomirov@242: 				daData.done();
tikhomirov@520: 				daData = null;
tikhomirov@242: 			}
tikhomirov@593: 			return rv;
tikhomirov@242: 		}
tikhomirov@584: 		
tikhomirov@584: 		private void readHeaderRecord(int i) throws IOException {
tikhomirov@584: 			if (inline && needData) {
tikhomirov@584: 				// inspector reading data (though FilterDataAccess) may have affected index position
tikhomirov@584: 				daIndex.seek(getIndexOffsetInt(i));
tikhomirov@584: 			}
tikhomirov@584: 			long l = daIndex.readLong(); // 0
tikhomirov@584: 			offset = i == 0 ? 0 : (l >>> 16);
tikhomirov@584: 			flags = (int) (l & 0x0FFFF);
tikhomirov@584: 			compressedLen = daIndex.readInt(); // +8
tikhomirov@584: 			actualLen = daIndex.readInt(); // +12
tikhomirov@584: 			baseRevision = daIndex.readInt(); // +16
tikhomirov@584: 			linkRevision = daIndex.readInt(); // +20
tikhomirov@584: 			parent1Revision = daIndex.readInt();
tikhomirov@584: 			parent2Revision = daIndex.readInt();
tikhomirov@584: 			// Hg has 32 bytes here, uses 20 for nodeid, and keeps 12 last bytes empty
tikhomirov@584: 			daIndex.readBytes(nodeidBuf, 0, 20); // +32
tikhomirov@584: 			daIndex.skip(12);
tikhomirov@584: 		}
tikhomirov@584: 		
tikhomirov@584: 		private boolean isPatch(int i) {
tikhomirov@584: 			return baseRevision != i; // the only way I found to tell if it's a patch
tikhomirov@584: 		}
tikhomirov@584: 		
tikhomirov@584: 		private DataAccess getStoredData(int i) throws IOException {
tikhomirov@584: 			DataAccess userDataAccess = null;
tikhomirov@584: 			DataAccess streamDataAccess;
tikhomirov@584: 			long streamOffset;
tikhomirov@584: 			if (inline) {
tikhomirov@584: 				streamOffset = getIndexOffsetInt(i) + REVLOGV1_RECORD_SIZE;
tikhomirov@584: 				streamDataAccess = daIndex;
tikhomirov@584: 				 // don't need to do seek as it's actual position in the index stream, but it's safe to seek, just in case
tikhomirov@584: 				daIndex.longSeek(streamOffset);
tikhomirov@584: 			} else {
tikhomirov@584: 				streamOffset = offset;
tikhomirov@584: 				streamDataAccess = daData;
tikhomirov@584: 				daData.longSeek(streamOffset);
tikhomirov@584: 			}
tikhomirov@584: 			if (streamDataAccess.isEmpty() || compressedLen == 0) {
tikhomirov@584: 				userDataAccess = new DataAccess(); // empty
tikhomirov@584: 			} else {
tikhomirov@584: 				final byte firstByte = streamDataAccess.readByte();
tikhomirov@584: 				if (firstByte == 0x78 /* 'x' */) {
tikhomirov@584: 					inflater.reset();
tikhomirov@584: 					userDataAccess = new InflaterDataAccess(streamDataAccess, streamOffset, compressedLen, isPatch(i) ? -1 : actualLen, inflater, inflaterBuffer);
tikhomirov@584: 				} else if (firstByte == 0x75 /* 'u' */) {
tikhomirov@584: 					userDataAccess = new FilterDataAccess(streamDataAccess, streamOffset+1, compressedLen-1);
tikhomirov@584: 				} else {
tikhomirov@584: 					// XXX Python impl in fact throws exception when there's not 'x', 'u' or '0' but I don't see reason not to return data as is
tikhomirov@584: 					//
tikhomirov@584: 					// although firstByte is already read from the streamDataAccess, FilterDataAccess#readByte would seek to
tikhomirov@584: 					// initial offset before first attempt to read a byte
tikhomirov@584: 					userDataAccess = new FilterDataAccess(streamDataAccess, streamOffset, compressedLen);
tikhomirov@584: 				}
tikhomirov@584: 			}
tikhomirov@584: 			return userDataAccess;
tikhomirov@584: 		}
tikhomirov@263: 
tikhomirov@520: 		// may be invoked few times per instance life
tikhomirov@423: 		public boolean range(int start, int end) throws IOException {
tikhomirov@242: 			int i;
tikhomirov@242: 			// it (i.e. replace with i >= start)
tikhomirov@242: 			if (needData && (i = getBaseRevision(start)) < start) {
tikhomirov@242: 				// if lastRevisionRead in [baseRevision(start), start)  can reuse lastUserData
tikhomirov@242: 				// doesn't make sense to reuse if lastRevisionRead == start (too much to change in the cycle below). 
tikhomirov@242: 				if (lastRevisionRead != BAD_REVISION && i <= lastRevisionRead && lastRevisionRead < start) {
tikhomirov@242: 					i = lastRevisionRead + 1; // start with first not-yet-read revision
tikhomirov@242: 				} else {
tikhomirov@242: 					if (lastUserData != null) {
tikhomirov@242: 						lastUserData.done();
tikhomirov@242: 						lastUserData = null;
tikhomirov@242: 					}
tikhomirov@242: 				}
tikhomirov@242: 			} else {
tikhomirov@242: 				// don't need to clean lastUserData as it's always null when !needData
tikhomirov@242: 				i = start;
tikhomirov@242: 			}
tikhomirov@242: 			
tikhomirov@242: 			daIndex.seek(getIndexOffsetInt(i));
tikhomirov@258: 			//
tikhomirov@584: 			// reuse instance, do not normalize it as patches from the stream are unlikely to need it
tikhomirov@584: 			final Patch patch = new Patch(false);
tikhomirov@584: 			//
tikhomirov@584: 			if (needData && mergePatches && start-i > 2) {
tikhomirov@584: 				// i+1 == start just reads lastUserData, i+2 == start applies one patch - not worth dedicated effort 
tikhomirov@584: 				Patch ultimatePatch = new Patch(true);
tikhomirov@584: 				for ( ; i < start; i++) {
tikhomirov@584: 					readHeaderRecord(i);
tikhomirov@584: 					DataAccess userDataAccess = getStoredData(i);
tikhomirov@584: 					if (lastUserData == null) {
tikhomirov@584: 						assert !isPatch(i);
tikhomirov@584: 						lastUserData = userDataAccess;
tikhomirov@584: 					} else {
tikhomirov@584: 						assert isPatch(i); // i < start and i == getBaseRevision()
tikhomirov@584: 						patch.read(userDataAccess);
tikhomirov@584: 						userDataAccess.done();
tikhomirov@584: 						// I assume empty patches are applied ok
tikhomirov@584: 						ultimatePatch = ultimatePatch.apply(patch);
tikhomirov@584: 						patch.clear();
tikhomirov@584: 					}
tikhomirov@584: 				}
tikhomirov@584: 				lastUserData.reset();
tikhomirov@584: 				byte[] userData = ultimatePatch.apply(lastUserData, actualLen);
tikhomirov@584: 				ultimatePatch.clear();
tikhomirov@584: 				lastUserData.done();
tikhomirov@584: 				lastUserData = new ByteArrayDataAccess(userData);
tikhomirov@584: 			}
tikhomirov@263: 			//
tikhomirov@242: 			
tikhomirov@242: 			for (; i <= end; i++ ) {
tikhomirov@584: 				readHeaderRecord(i);
tikhomirov@242: 				DataAccess userDataAccess = null;
tikhomirov@242: 				if (needData) {
tikhomirov@584: 					userDataAccess = getStoredData(i);
tikhomirov@397: 					// userDataAccess is revision content, either complete revision, patch of a previous content, or an empty patch
tikhomirov@584: 					if (isPatch(i)) {
tikhomirov@242: 						// this is a patch
tikhomirov@397: 						if (userDataAccess.isEmpty()) {
tikhomirov@397: 							// Issue 22, empty patch to an empty base revision
tikhomirov@397: 							// Issue 24, empty patch to non-empty base revision
tikhomirov@397: 							// empty patch modifies nothing, use content of a previous revision (shall present - it's a patch here)
tikhomirov@397: 							//
tikhomirov@397: 							assert lastUserData.length() == actualLen; // with no patch, data size shall be the same
tikhomirov@397: 							userDataAccess = lastUserData;
tikhomirov@397: 						} else {
tikhomirov@397: 							patch.read(userDataAccess);
tikhomirov@397: 							userDataAccess.done();
tikhomirov@397: 							//
tikhomirov@397: 							// it shall be reset at the end of prev iteration, when it got assigned from userDataAccess
tikhomirov@397: 							// however, actual userDataAccess and lastUserData may share Inflater object, which needs to be reset
tikhomirov@397: 							// Alternatively, userDataAccess.done() above may be responsible to reset Inflater (if it's InflaterDataAccess)
tikhomirov@397: 							lastUserData.reset();
tikhomirov@397: //							final long startMeasuring = System.currentTimeMillis(); // TIMING
tikhomirov@397: 							byte[] userData = patch.apply(lastUserData, actualLen);
tikhomirov@397: //							applyTime += (System.currentTimeMillis() - startMeasuring); // TIMING
tikhomirov@397: 							patch.clear(); // do not keep any reference, allow byte[] data to be gc'd
tikhomirov@397: 							userDataAccess = new ByteArrayDataAccess(userData);
tikhomirov@397: 						}
tikhomirov@242: 					}
tikhomirov@242: 				} else {
tikhomirov@242: 					if (inline) {
tikhomirov@242: 						daIndex.skip(compressedLen);
tikhomirov@242: 					}
tikhomirov@242: 				}
tikhomirov@329: 				if (i >= start) {
tikhomirov@264: //					final long startMeasuring = System.currentTimeMillis(); // TIMING
tikhomirov@242: 					inspector.next(i, actualLen, baseRevision, linkRevision, parent1Revision, parent2Revision, nodeidBuf, userDataAccess);
tikhomirov@264: //					inspectorTime += (System.currentTimeMillis() - startMeasuring); // TIMING
tikhomirov@242: 				}
tikhomirov@242: 				if (cb != null) {
tikhomirov@242: 					if (cb.isStopped()) {
tikhomirov@242: 						return false;
tikhomirov@242: 					}
tikhomirov@242: 				}
tikhomirov@242: 				if (userDataAccess != null) {
tikhomirov@263: 					userDataAccess.reset(); // not sure this is necessary here, as lastUserData would get reset anyway before next use.
tikhomirov@242: 				}
tikhomirov@397: 				if (lastUserData != null && lastUserData != userDataAccess /* empty patch case, reuse of recent data in actual revision */) {
tikhomirov@397: 					// release lastUserData only if we didn't reuse it in actual revision due to empty patch:
tikhomirov@397: 					// empty patch means we have previous revision and didn't alter it with a patch, hence use lastUserData for userDataAccess above
tikhomirov@263: 					lastUserData.done();
tikhomirov@263: 				}
tikhomirov@263: 				lastUserData = userDataAccess;
tikhomirov@242: 			}
tikhomirov@242: 			lastRevisionRead = end;
tikhomirov@242: 			return true;
tikhomirov@242: 		}
tikhomirov@242: 	}
tikhomirov@242: 
tikhomirov@242: 	
tikhomirov@77: 	public interface Inspector {
tikhomirov@608: 		/**
tikhomirov@608: 		 * XXX boolean retVal to indicate whether to continue?
tikhomirov@608: 		 * 
tikhomirov@608: 		 * Implementers shall not invoke DataAccess.done(), it's accomplished by #iterate at appropriate moment
tikhomirov@608: 		 * 
tikhomirov@608: 		 * @param revisionIndex absolute index of revision in revlog being iterated
tikhomirov@608: 		 * @param actualLen length of the user data at this revision
tikhomirov@608: 		 * @param baseRevision last revision known to hold complete revision (other hold patches). 
tikhomirov@608: 		 *        if baseRevision != revisionIndex, data for this revision is a result of a sequence of patches
tikhomirov@608: 		 * @param linkRevision index of corresponding changeset revision
tikhomirov@608: 		 * @param parent1Revision index of first parent revision in this revlog, or {@link HgRepository#NO_REVISION}
tikhomirov@608: 		 * @param parent2Revision index of second parent revision in this revlog, or {@link HgRepository#NO_REVISION}
tikhomirov@608: 		 * @param nodeid 20-byte buffer, shared between invocations 
tikhomirov@608: 		 * @param data access to revision content of actualLen size, or <code>null</code> if no data has been requested with 
tikhomirov@608: 		 *        {@link RevlogStream#iterate(int[], boolean, Inspector)}
tikhomirov@608: 		 */
tikhomirov@423: 		void next(int revisionIndex, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[/*20*/] nodeid, DataAccess data);
tikhomirov@3: 	}
tikhomirov@539: 
tikhomirov@607: 	public interface Observer {
tikhomirov@607: 		// notify observer of invalidate/reload event in the stream
tikhomirov@607: 		public void reloaded(RevlogStream src);
tikhomirov@607: 	}
tikhomirov@0: }