--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hg4j/src/main/java/org/tmatesoft/hg/core/HgCloneCommand.java	Tue May 10 10:52:53 2011 +0200
@@ -0,0 +1,333 @@
+/*
+ * Copyright (c) 2011 TMate Software Ltd
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * For information on how to redistribute this software under
+ * the terms of a license other than GNU General Public License
+ * contact TMate Software at support@hg4j.com
+ */
+package org.tmatesoft.hg.core;
+
+import static org.tmatesoft.hg.core.Nodeid.NULL;
+import static org.tmatesoft.hg.internal.RequiresFile.*;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.TreeMap;
+import java.util.zip.DeflaterOutputStream;
+
+import org.tmatesoft.hg.internal.ByteArrayDataAccess;
+import org.tmatesoft.hg.internal.DataAccess;
+import org.tmatesoft.hg.internal.DigestHelper;
+import org.tmatesoft.hg.internal.Internals;
+import org.tmatesoft.hg.repo.HgBundle;
+import org.tmatesoft.hg.repo.HgBundle.GroupElement;
+import org.tmatesoft.hg.repo.HgLookup;
+import org.tmatesoft.hg.repo.HgRemoteRepository;
+import org.tmatesoft.hg.repo.HgRepository;
+import org.tmatesoft.hg.util.CancelledException;
+import org.tmatesoft.hg.util.PathRewrite;
+
+/**
+ * WORK IN PROGRESS, DO NOT USE
+ *
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class HgCloneCommand {
+
+	private File destination;
+	private HgRemoteRepository srcRepo;
+
+	public HgCloneCommand() {
+	}
+	
+	/**
+	 * @param folder location to become root of the repository (i.e. where <em>.hg</em> folder would reside). Either 
+	 * shall not exist or be empty otherwise. 
+	 * @return <code>this</code> for convenience
+	 */
+	public HgCloneCommand destination(File folder) {
+		destination = folder;
+		return this;
+	}
+
+	public HgCloneCommand source(HgRemoteRepository hgRemote) {
+		srcRepo = hgRemote;
+		return this;
+	}
+
+	public HgRepository execute() throws HgException, CancelledException {
+		if (destination == null) {
+			throw new HgBadArgumentException("Destination not set", null);
+		}
+		if (srcRepo == null || srcRepo.isInvalid()) {
+			throw new HgBadArgumentException("Bad source repository", null);
+		}
+		if (destination.exists()) {
+			if (!destination.isDirectory()) {
+				throw new HgBadArgumentException(String.format("%s is not a directory", destination), null);
+			} else if (destination.list().length > 0) {
+				throw new HgBadArgumentException(String.format("% shall be empty", destination), null);
+			}
+		} else {
+			destination.mkdirs();
+		}
+		// if cloning remote repo, which can stream and no revision is specified -
+		// can use 'stream_out' wireproto
+		//
+		// pull all changes from the very beginning
+		// XXX consult getContext() if by any chance has a bundle ready, if not, then read and register 
+		HgBundle completeChanges = srcRepo.getChanges(Collections.singletonList(NULL));
+		WriteDownMate mate = new WriteDownMate(destination);
+		try {
+			// instantiate new repo in the destdir
+			mate.initEmptyRepository();
+			// pull changes
+			completeChanges.inspectAll(mate);
+			mate.complete();
+		} catch (IOException ex) {
+			throw new HgException(ex);
+		} finally {
+			completeChanges.unlink();
+		}
+		return new HgLookup().detect(destination);
+	}
+
+
+	// 1. process changelog, memorize nodeids to index
+	// 2. process manifest, using map from step 3, collect manifest nodeids
+	// 3. process every file, using map from 3, and consult set from step 4 to ensure repo is correct
+	private static class WriteDownMate implements HgBundle.Inspector {
+		private final File hgDir;
+		private final PathRewrite storagePathHelper;
+		private FileOutputStream indexFile;
+		private String filename; // human-readable name of the file being written, for log/exception purposes 
+
+		private final TreeMap<Nodeid, Integer> changelogIndexes = new TreeMap<Nodeid, Integer>();
+		private boolean collectChangelogIndexes = false;
+
+		private int base = -1;
+		private long offset = 0;
+		private DataAccess prevRevContent;
+		private final DigestHelper dh = new DigestHelper();
+		private final ArrayList<Nodeid> revisionSequence = new ArrayList<Nodeid>(); // last visited nodes first
+
+		private final LinkedList<String> fncacheFiles = new LinkedList<String>();
+		private Internals implHelper;
+
+		public WriteDownMate(File destDir) {
+			hgDir = new File(destDir, ".hg");
+			implHelper = new Internals();
+			implHelper.setStorageConfig(1, STORE | FNCACHE | DOTENCODE);
+			storagePathHelper = implHelper.buildDataFilesHelper();
+		}
+
+		public void initEmptyRepository() throws IOException {
+			implHelper.initEmptyRepository(hgDir);
+		}
+
+		public void complete() throws IOException {
+			FileOutputStream fncacheFile = new FileOutputStream(new File(hgDir, "store/fncache"));
+			for (String s : fncacheFiles) {
+				fncacheFile.write(s.getBytes());
+				fncacheFile.write(0x0A); // http://mercurial.selenic.com/wiki/fncacheRepoFormat
+			}
+			fncacheFile.close();
+		}
+
+		public void changelogStart() {
+			try {
+				base = -1;
+				offset = 0;
+				revisionSequence.clear();
+				indexFile = new FileOutputStream(new File(hgDir, filename = "store/00changelog.i"));
+				collectChangelogIndexes = true;
+			} catch (IOException ex) {
+				throw new HgBadStateException(ex);
+			}
+		}
+
+		public void changelogEnd() {
+			try {
+				if (prevRevContent != null) {
+					prevRevContent.done();
+					prevRevContent = null;
+				}
+				collectChangelogIndexes = false;
+				indexFile.close();
+				indexFile = null;
+				filename = null;
+			} catch (IOException ex) {
+				throw new HgBadStateException(ex);
+			}
+		}
+
+		public void manifestStart() {
+			try {
+				base = -1;
+				offset = 0;
+				revisionSequence.clear();
+				indexFile = new FileOutputStream(new File(hgDir, filename = "store/00manifest.i"));
+			} catch (IOException ex) {
+				throw new HgBadStateException(ex);
+			}
+		}
+
+		public void manifestEnd() {
+			try {
+				if (prevRevContent != null) {
+					prevRevContent.done();
+					prevRevContent = null;
+				}
+				indexFile.close();
+				indexFile = null;
+				filename = null;
+			} catch (IOException ex) {
+				throw new HgBadStateException(ex);
+			}
+		}
+		
+		public void fileStart(String name) {
+			try {
+				base = -1;
+				offset = 0;
+				revisionSequence.clear();
+				fncacheFiles.add("data/" + name + ".i"); // FIXME this is pure guess, 
+				// need to investigate more how filenames are kept in fncache
+				File file = new File(hgDir, filename = storagePathHelper.rewrite(name));
+				file.getParentFile().mkdirs();
+				indexFile = new FileOutputStream(file);
+			} catch (IOException ex) {
+				throw new HgBadStateException(ex);
+			}
+		}
+
+		public void fileEnd(String name) {
+			try {
+				if (prevRevContent != null) {
+					prevRevContent.done();
+					prevRevContent = null;
+				}
+				indexFile.close();
+				indexFile = null;
+				filename = null;
+			} catch (IOException ex) {
+				throw new HgBadStateException(ex);
+			}
+		}
+
+		private int knownRevision(Nodeid p) {
+			if (NULL.equals(p)) {
+				return -1;
+			} else {
+				for (int i = revisionSequence.size() - 1; i >= 0; i--) {
+					if (revisionSequence.get(i).equals(p)) {
+						return i;
+					}
+				}
+			}
+			throw new HgBadStateException(String.format("Can't find index of %s for file %s", p.shortNotation(), filename));
+		}
+
+		public boolean element(GroupElement ge) {
+			try {
+				assert indexFile != null;
+				boolean writeComplete = false;
+				Nodeid p1 = ge.firstParent();
+				Nodeid p2 = ge.secondParent();
+				if (NULL.equals(p1) && NULL.equals(p2) /* or forced flag, does REVIDX_PUNCHED_FLAG indicate that? */) {
+					prevRevContent = new ByteArrayDataAccess(new byte[0]);
+					writeComplete = true;
+				}
+				byte[] content = ge.apply(prevRevContent);
+				byte[] calculated = dh.sha1(p1, p2, content).asBinary();
+				final Nodeid node = ge.node();
+				if (!node.equalsTo(calculated)) {
+					throw new HgBadStateException(String.format("Checksum failed: expected %s, calculated %s. File %s", node, calculated, filename));
+				}
+				final int link;
+				if (collectChangelogIndexes) {
+					changelogIndexes.put(node, revisionSequence.size());
+					link = revisionSequence.size();
+				} else {
+					Integer csRev = changelogIndexes.get(ge.cset());
+					if (csRev == null) {
+						throw new HgBadStateException(String.format("Changelog doesn't contain revision %s of %s", ge.cset().shortNotation(), filename));
+					}
+					link = csRev.intValue();
+				}
+				final int p1Rev = knownRevision(p1), p2Rev = knownRevision(p2);
+				DataAccess patchContent = ge.rawData();
+				writeComplete = writeComplete || patchContent.length() >= (/* 3/4 of actual */content.length - (content.length >>> 2));
+				if (writeComplete) {
+					base = revisionSequence.size();
+				}
+				final byte[] sourceData = writeComplete ? content : patchContent.byteArray();
+				final byte[] data;
+				ByteArrayOutputStream bos = new ByteArrayOutputStream(content.length);
+				DeflaterOutputStream dos = new DeflaterOutputStream(bos);
+				dos.write(sourceData);
+				dos.close();
+				final byte[] compressedData = bos.toByteArray();
+				dos = null;
+				bos = null;
+				final Byte dataPrefix;
+				if (compressedData.length >= (sourceData.length - (sourceData.length >>> 2))) {
+					// compression wasn't too effective,
+					data = sourceData;
+					dataPrefix = 'u';
+				} else {
+					data = compressedData;
+					dataPrefix = null;
+				}
+
+				ByteBuffer header = ByteBuffer.allocate(64 /* REVLOGV1_RECORD_SIZE */);
+				if (offset == 0) {
+					final int INLINEDATA = 1 << 16;
+					header.putInt(1 /* RevlogNG */ | INLINEDATA);
+					header.putInt(0);
+				} else {
+					header.putLong(offset << 16);
+				}
+				final int compressedLen = data.length + (dataPrefix == null ? 0 : 1);
+				header.putInt(compressedLen);
+				header.putInt(content.length);
+				header.putInt(base);
+				header.putInt(link);
+				header.putInt(p1Rev);
+				header.putInt(p2Rev);
+				header.put(node.toByteArray());
+				// assume 12 bytes left are zeros
+				indexFile.write(header.array());
+				if (dataPrefix != null) {
+					indexFile.write(dataPrefix.byteValue());
+				}
+				indexFile.write(data);
+				//
+				offset += compressedLen;
+				revisionSequence.add(node);
+				prevRevContent.done();
+				prevRevContent = new ByteArrayDataAccess(content);
+			} catch (IOException ex) {
+				throw new HgBadStateException(ex);
+			}
+			return true;
+		}
+	}
+
+}