From 73eb32be829c0f2167c2796ce1ba60bdf4a6b88a Mon Sep 17 00:00:00 2001 From: Shawn Pearce Date: Tue, 17 Nov 2015 16:22:18 -0800 Subject: [PATCH] RefTree: Store references in a Git tree A group of updates can be applied by updating the tree in one step, writing out a new root tree, and storing its SHA-1. If references are stored in RefTrees, comparing two repositories is a matter of checking if two SHA-1s are identical. Without RefTrees comparing two repositories requires listing all references and comparing the sets. Track the "refs/" directory as a root tree by storing references that point directly at an object as a GITLINK entry in the tree. For example "refs/heads/master" is written as "heads/master". Annotated tags also store their peeled value with ^{} suffix, using "tags/v1.0" and "tags/v1.0^{}" GITLINK entries. Symbolic references are written as SYMLINK entries with the blob of the symlink carrying the name of the symbolic reference target. HEAD is outside of "refs/" namespace so it is stored as a special "..HEAD" entry. This name is chosen because ".." is not valid in a reference name and it almost looks like "../HEAD" which names HEAD if the reader was inside of the "refs/" directory. A new Command type is required to handle symbolic references and peeled references. Change-Id: Id47e5d4d32149a9e500854147edd7d93c1041a39 --- org.eclipse.jgit.test/META-INF/MANIFEST.MF | 1 + .../internal/storage/reftree/RefTreeTest.java | 303 +++++++++++++ org.eclipse.jgit/META-INF/MANIFEST.MF | 1 + .../eclipse/jgit/dircache/DirCacheEntry.java | 17 + .../internal/storage/reftree/Command.java | 290 +++++++++++++ .../internal/storage/reftree/RefTree.java | 410 ++++++++++++++++++ .../src/org/eclipse/jgit/lib/RefDatabase.java | 4 +- 7 files changed, 1025 insertions(+), 1 deletion(-) create mode 100644 org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftree/RefTreeTest.java create mode 100644 org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftree/Command.java create mode 100644 org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftree/RefTree.java diff --git a/org.eclipse.jgit.test/META-INF/MANIFEST.MF b/org.eclipse.jgit.test/META-INF/MANIFEST.MF index 37fd367171..f78fe5b24b 100644 --- a/org.eclipse.jgit.test/META-INF/MANIFEST.MF +++ b/org.eclipse.jgit.test/META-INF/MANIFEST.MF @@ -26,6 +26,7 @@ Import-Package: com.googlecode.javaewah;version="[0.7.9,0.8.0)", org.eclipse.jgit.internal.storage.dfs;version="[4.2.0,4.3.0)", org.eclipse.jgit.internal.storage.file;version="[4.2.0,4.3.0)", org.eclipse.jgit.internal.storage.pack;version="[4.2.0,4.3.0)", + org.eclipse.jgit.internal.storage.reftree;version="[4.2.0,4.3.0)", org.eclipse.jgit.junit;version="[4.2.0,4.3.0)", org.eclipse.jgit.lib;version="[4.2.0,4.3.0)", org.eclipse.jgit.merge;version="[4.2.0,4.3.0)", diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftree/RefTreeTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftree/RefTreeTest.java new file mode 100644 index 0000000000..8e0f38c69a --- /dev/null +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftree/RefTreeTest.java @@ -0,0 +1,303 @@ +/* + * Copyright (C) 2016, Google Inc. + * and other copyright owners as documented in the project's IP log. + * + * This program and the accompanying materials are made available + * under the terms of the Eclipse Distribution License v1.0 which + * accompanies this distribution, is reproduced below, and is + * available at http://www.eclipse.org/org/documents/edl-v10.php + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * - Neither the name of the Eclipse Foundation, Inc. nor the + * names of its contributors may be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +package org.eclipse.jgit.internal.storage.reftree; + +import static org.eclipse.jgit.lib.Constants.HEAD; +import static org.eclipse.jgit.lib.Constants.R_HEADS; +import static org.eclipse.jgit.lib.Constants.R_TAGS; +import static org.eclipse.jgit.lib.Ref.Storage.LOOSE; +import static org.eclipse.jgit.lib.Ref.Storage.NEW; +import static org.eclipse.jgit.transport.ReceiveCommand.Result.LOCK_FAILURE; +import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED; +import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_OTHER_REASON; +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertNotNull; +import static org.junit.Assert.assertNull; +import static org.junit.Assert.assertSame; +import static org.junit.Assert.assertTrue; + +import java.io.IOException; +import java.util.Arrays; +import java.util.Collections; + +import org.eclipse.jgit.errors.MissingObjectException; +import org.eclipse.jgit.internal.JGitText; +import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription; +import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository; +import org.eclipse.jgit.junit.TestRepository; +import org.eclipse.jgit.lib.ObjectId; +import org.eclipse.jgit.lib.ObjectIdRef; +import org.eclipse.jgit.lib.ObjectInserter; +import org.eclipse.jgit.lib.ObjectReader; +import org.eclipse.jgit.lib.Ref; +import org.eclipse.jgit.lib.SymbolicRef; +import org.eclipse.jgit.revwalk.RevBlob; +import org.eclipse.jgit.revwalk.RevTag; +import org.eclipse.jgit.revwalk.RevWalk; +import org.eclipse.jgit.transport.ReceiveCommand; +import org.junit.Before; +import org.junit.Test; + +public class RefTreeTest { + private static final String R_MASTER = R_HEADS + "master"; + private InMemoryRepository repo; + private TestRepository git; + + @Before + public void setUp() throws IOException { + repo = new InMemoryRepository(new DfsRepositoryDescription("RefTree")); + git = new TestRepository<>(repo); + } + + @Test + public void testEmptyTree() throws IOException { + RefTree tree = RefTree.newEmptyTree(); + try (ObjectReader reader = repo.newObjectReader()) { + assertNull(HEAD, tree.exactRef(reader, HEAD)); + assertNull("master", tree.exactRef(reader, R_MASTER)); + } + } + + @Test + public void testApplyThenReadMaster() throws Exception { + RefTree tree = RefTree.newEmptyTree(); + RevBlob id = git.blob("A"); + Command cmd = new Command(null, ref(R_MASTER, id)); + assertTrue(tree.apply(Collections.singletonList(cmd))); + assertSame(NOT_ATTEMPTED, cmd.getResult()); + + try (ObjectReader reader = repo.newObjectReader()) { + Ref m = tree.exactRef(reader, R_MASTER); + assertNotNull(R_MASTER, m); + assertEquals(R_MASTER, m.getName()); + assertEquals(id, m.getObjectId()); + assertTrue("peeled", m.isPeeled()); + } + } + + @Test + public void testUpdateMaster() throws Exception { + RefTree tree = RefTree.newEmptyTree(); + RevBlob id1 = git.blob("A"); + Command cmd1 = new Command(null, ref(R_MASTER, id1)); + assertTrue(tree.apply(Collections.singletonList(cmd1))); + assertSame(NOT_ATTEMPTED, cmd1.getResult()); + + RevBlob id2 = git.blob("B"); + Command cmd2 = new Command(ref(R_MASTER, id1), ref(R_MASTER, id2)); + assertTrue(tree.apply(Collections.singletonList(cmd2))); + assertSame(NOT_ATTEMPTED, cmd2.getResult()); + + try (ObjectReader reader = repo.newObjectReader()) { + Ref m = tree.exactRef(reader, R_MASTER); + assertNotNull(R_MASTER, m); + assertEquals(R_MASTER, m.getName()); + assertEquals(id2, m.getObjectId()); + assertTrue("peeled", m.isPeeled()); + } + } + + @Test + public void testHeadSymref() throws Exception { + RefTree tree = RefTree.newEmptyTree(); + RevBlob id = git.blob("A"); + Command cmd1 = new Command(null, ref(R_MASTER, id)); + Command cmd2 = new Command(null, symref(HEAD, R_MASTER)); + assertTrue(tree.apply(Arrays.asList(new Command[] { cmd1, cmd2 }))); + assertSame(NOT_ATTEMPTED, cmd1.getResult()); + assertSame(NOT_ATTEMPTED, cmd2.getResult()); + + try (ObjectReader reader = repo.newObjectReader()) { + Ref m = tree.exactRef(reader, HEAD); + assertNotNull(HEAD, m); + assertEquals(HEAD, m.getName()); + assertTrue("symbolic", m.isSymbolic()); + assertNotNull(m.getTarget()); + assertEquals(R_MASTER, m.getTarget().getName()); + assertEquals(id, m.getTarget().getObjectId()); + } + + // Writing flushes some buffers, re-read from blob. + ObjectId newId = write(tree); + try (ObjectReader reader = repo.newObjectReader(); + RevWalk rw = new RevWalk(reader)) { + tree = RefTree.read(reader, rw.parseTree(newId)); + Ref m = tree.exactRef(reader, HEAD); + assertEquals(R_MASTER, m.getTarget().getName()); + } + } + + @Test + public void testTagIsPeeled() throws Exception { + String name = "v1.0"; + RefTree tree = RefTree.newEmptyTree(); + RevBlob id = git.blob("A"); + RevTag tag = git.tag(name, id); + + String ref = R_TAGS + name; + Command cmd = create(ref, tag); + assertTrue(tree.apply(Collections.singletonList(cmd))); + assertSame(NOT_ATTEMPTED, cmd.getResult()); + + try (ObjectReader reader = repo.newObjectReader()) { + Ref m = tree.exactRef(reader, ref); + assertNotNull(ref, m); + assertEquals(ref, m.getName()); + assertEquals(tag, m.getObjectId()); + assertTrue("peeled", m.isPeeled()); + assertEquals(id, m.getPeeledObjectId()); + } + } + + @Test + public void testApplyAlreadyExists() throws Exception { + RefTree tree = RefTree.newEmptyTree(); + RevBlob a = git.blob("A"); + Command cmd = new Command(null, ref(R_MASTER, a)); + assertTrue(tree.apply(Collections.singletonList(cmd))); + ObjectId treeId = write(tree); + + RevBlob b = git.blob("B"); + Command cmd1 = create(R_MASTER, b); + Command cmd2 = create(R_MASTER, b); + assertFalse(tree.apply(Arrays.asList(new Command[] { cmd1, cmd2 }))); + assertSame(LOCK_FAILURE, cmd1.getResult()); + assertSame(REJECTED_OTHER_REASON, cmd2.getResult()); + assertEquals(JGitText.get().transactionAborted, cmd2.getMessage()); + assertEquals(treeId, write(tree)); + } + + @Test + public void testApplyWrongOldId() throws Exception { + RefTree tree = RefTree.newEmptyTree(); + RevBlob a = git.blob("A"); + Command cmd = new Command(null, ref(R_MASTER, a)); + assertTrue(tree.apply(Collections.singletonList(cmd))); + ObjectId treeId = write(tree); + + RevBlob b = git.blob("B"); + RevBlob c = git.blob("C"); + Command cmd1 = update(R_MASTER, b, c); + Command cmd2 = create(R_MASTER, b); + assertFalse(tree.apply(Arrays.asList(new Command[] { cmd1, cmd2 }))); + assertSame(LOCK_FAILURE, cmd1.getResult()); + assertSame(REJECTED_OTHER_REASON, cmd2.getResult()); + assertEquals(JGitText.get().transactionAborted, cmd2.getMessage()); + assertEquals(treeId, write(tree)); + } + + @Test + public void testApplyWrongOldIdButAlreadyCurrentIsNoOp() throws Exception { + RefTree tree = RefTree.newEmptyTree(); + RevBlob a = git.blob("A"); + Command cmd = new Command(null, ref(R_MASTER, a)); + assertTrue(tree.apply(Collections.singletonList(cmd))); + ObjectId treeId = write(tree); + + RevBlob b = git.blob("B"); + cmd = update(R_MASTER, b, a); + assertTrue(tree.apply(Collections.singletonList(cmd))); + assertEquals(treeId, write(tree)); + } + + @Test + public void testApplyCannotCreateSubdirectory() throws Exception { + RefTree tree = RefTree.newEmptyTree(); + RevBlob a = git.blob("A"); + Command cmd = new Command(null, ref(R_MASTER, a)); + assertTrue(tree.apply(Collections.singletonList(cmd))); + ObjectId treeId = write(tree); + + RevBlob b = git.blob("B"); + Command cmd1 = create(R_MASTER + "/fail", b); + assertFalse(tree.apply(Collections.singletonList(cmd1))); + assertSame(LOCK_FAILURE, cmd1.getResult()); + assertEquals(treeId, write(tree)); + } + + @Test + public void testApplyCannotCreateParentRef() throws Exception { + RefTree tree = RefTree.newEmptyTree(); + RevBlob a = git.blob("A"); + Command cmd = new Command(null, ref(R_MASTER, a)); + assertTrue(tree.apply(Collections.singletonList(cmd))); + ObjectId treeId = write(tree); + + RevBlob b = git.blob("B"); + Command cmd1 = create("refs/heads", b); + assertFalse(tree.apply(Collections.singletonList(cmd1))); + assertSame(LOCK_FAILURE, cmd1.getResult()); + assertEquals(treeId, write(tree)); + } + + private static Ref ref(String name, ObjectId id) { + return new ObjectIdRef.PeeledNonTag(LOOSE, name, id); + } + + private static Ref symref(String name, String dest) { + Ref d = new ObjectIdRef.PeeledNonTag(NEW, dest, null); + return new SymbolicRef(name, d); + } + + private Command create(String name, ObjectId id) + throws MissingObjectException, IOException { + return update(name, ObjectId.zeroId(), id); + } + + private Command update(String name, ObjectId oldId, ObjectId newId) + throws MissingObjectException, IOException { + try (RevWalk rw = new RevWalk(repo)) { + return new Command(rw, new ReceiveCommand(oldId, newId, name)); + } + } + + private ObjectId write(RefTree tree) throws IOException { + try (ObjectInserter ins = repo.newObjectInserter()) { + ObjectId id = tree.writeTree(ins); + ins.flush(); + return id; + } + } +} diff --git a/org.eclipse.jgit/META-INF/MANIFEST.MF b/org.eclipse.jgit/META-INF/MANIFEST.MF index 66529d3afb..25d0be6ec7 100644 --- a/org.eclipse.jgit/META-INF/MANIFEST.MF +++ b/org.eclipse.jgit/META-INF/MANIFEST.MF @@ -68,6 +68,7 @@ Export-Package: org.eclipse.jgit.annotations;version="4.2.0", org.eclipse.jgit.pgm.test, org.eclipse.jgit.pgm", org.eclipse.jgit.internal.storage.pack;version="4.2.0";x-friends:="org.eclipse.jgit.junit,org.eclipse.jgit.test,org.eclipse.jgit.pgm", + org.eclipse.jgit.internal.storage.reftree;version="4.2.0";x-friends:="org.eclipse.jgit.junit,org.eclipse.jgit.test,org.eclipse.jgit.pgm", org.eclipse.jgit.lib;version="4.2.0"; uses:="org.eclipse.jgit.revwalk, org.eclipse.jgit.treewalk.filter, diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheEntry.java b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheEntry.java index 5df9e0b4df..4ebf2e0d71 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheEntry.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheEntry.java @@ -294,6 +294,23 @@ public class DirCacheEntry { NB.encodeInt16(info, infoOffset + P_FLAGS, flags); } + /** + * Duplicate DirCacheEntry with same path and copied info. + *

+ * The same path buffer is reused (avoiding copying), however a new info + * buffer is created and its contents are copied. + * + * @param src + * entry to clone. + * @since 4.2 + */ + public DirCacheEntry(DirCacheEntry src) { + path = src.path; + info = new byte[INFO_LEN]; + infoOffset = 0; + System.arraycopy(src.info, src.infoOffset, info, 0, INFO_LEN); + } + void write(final OutputStream os) throws IOException { final int len = isExtended() ? INFO_LEN_EXTENDED : INFO_LEN; final int pathLen = path.length; diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftree/Command.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftree/Command.java new file mode 100644 index 0000000000..9ac375f168 --- /dev/null +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftree/Command.java @@ -0,0 +1,290 @@ +/* + * Copyright (C) 2016, Google Inc. + * and other copyright owners as documented in the project's IP log. + * + * This program and the accompanying materials are made available + * under the terms of the Eclipse Distribution License v1.0 which + * accompanies this distribution, is reproduced below, and is + * available at http://www.eclipse.org/org/documents/edl-v10.php + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * - Neither the name of the Eclipse Foundation, Inc. nor the + * names of its contributors may be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +package org.eclipse.jgit.internal.storage.reftree; + +import static org.eclipse.jgit.lib.Constants.OBJ_BLOB; +import static org.eclipse.jgit.lib.Constants.encode; +import static org.eclipse.jgit.lib.FileMode.TYPE_GITLINK; +import static org.eclipse.jgit.lib.FileMode.TYPE_SYMLINK; +import static org.eclipse.jgit.lib.Ref.Storage.NETWORK; +import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED; + +import java.io.IOException; + +import org.eclipse.jgit.annotations.Nullable; +import org.eclipse.jgit.dircache.DirCacheEntry; +import org.eclipse.jgit.errors.MissingObjectException; +import org.eclipse.jgit.lib.ObjectId; +import org.eclipse.jgit.lib.ObjectIdRef; +import org.eclipse.jgit.lib.ObjectInserter; +import org.eclipse.jgit.lib.Ref; +import org.eclipse.jgit.revwalk.RevObject; +import org.eclipse.jgit.revwalk.RevTag; +import org.eclipse.jgit.revwalk.RevWalk; +import org.eclipse.jgit.transport.ReceiveCommand; +import org.eclipse.jgit.transport.ReceiveCommand.Result; + +/** + * Command to create, update or delete an entry inside a {@link RefTree}. + *

+ * Unlike {@link ReceiveCommand} (which can only update a reference to an + * {@link ObjectId}), a RefTree Command can also create, modify or delete + * symbolic references to a target reference. + *

+ * RefTree Commands may wrap a {@code ReceiveCommand} to allow callers to + * process an existing ReceiveCommand against a RefTree. + *

+ * Commands should be passed into {@link RefTree#apply(java.util.Collection)} + * for processing. + */ +public class Command { + private final Ref oldRef; + private final Ref newRef; + private final ReceiveCommand cmd; + private Result result; + + /** + * Create a command to create, update or delete a reference. + *

+ * At least one of {@code oldRef} or {@code newRef} must be supplied. + * + * @param oldRef + * expected value. Null if the ref should not exist. + * @param newRef + * desired value, must be peeled if not null and not symbolic. + * Null to delete the ref. + */ + public Command(@Nullable Ref oldRef, @Nullable Ref newRef) { + this.oldRef = oldRef; + this.newRef = newRef; + this.cmd = null; + this.result = NOT_ATTEMPTED; + + if (oldRef == null && newRef == null) { + throw new IllegalArgumentException(); + } + if (newRef != null && !newRef.isPeeled() && !newRef.isSymbolic()) { + throw new IllegalArgumentException(); + } + if (oldRef != null && newRef != null + && !oldRef.getName().equals(newRef.getName())) { + throw new IllegalArgumentException(); + } + } + + /** + * Construct a RefTree command wrapped around a ReceiveCommand. + * + * @param rw + * walk instance to peel the {@code newId}. + * @param cmd + * command received from a push client. + * @throws MissingObjectException + * {@code oldId} or {@code newId} is missing. + * @throws IOException + * {@code oldId} or {@code newId} cannot be peeled. + */ + public Command(RevWalk rw, ReceiveCommand cmd) + throws MissingObjectException, IOException { + this.oldRef = toRef(rw, cmd.getOldId(), cmd.getRefName(), false); + this.newRef = toRef(rw, cmd.getNewId(), cmd.getRefName(), true); + this.cmd = cmd; + } + + private static Ref toRef(RevWalk rw, ObjectId id, String name, + boolean mustExist) throws MissingObjectException, IOException { + if (ObjectId.zeroId().equals(id)) { + return null; + } + + try { + RevObject o = rw.parseAny(id); + if (o instanceof RevTag) { + RevObject p = rw.peel(o); + return new ObjectIdRef.PeeledTag(NETWORK, name, id, p.copy()); + } + return new ObjectIdRef.PeeledNonTag(NETWORK, name, id); + } catch (MissingObjectException e) { + if (mustExist) { + throw e; + } + return new ObjectIdRef.Unpeeled(NETWORK, name, id); + } + } + + /** @return name of the reference affected by this command. */ + public String getRefName() { + if (cmd != null) { + return cmd.getRefName(); + } else if (newRef != null) { + return newRef.getName(); + } + return oldRef.getName(); + } + + /** + * Set the result of this command. + * + * @param result + * the command result. + */ + public void setResult(Result result) { + setResult(result, null); + } + + /** + * Set the result of this command. + * + * @param result + * the command result. + * @param why + * optional message explaining the result status. + */ + public void setResult(Result result, @Nullable String why) { + if (cmd != null) { + cmd.setResult(result, why); + } else { + this.result = result; + } + } + + /** @return result of executing this command. */ + public Result getResult() { + return cmd != null ? cmd.getResult() : result; + } + + /** @return optional message explaining command failure. */ + @Nullable + public String getMessage() { + return cmd != null ? cmd.getMessage() : null; + } + + /** + * Old peeled reference. + * + * @return the old reference; null if the command is creating the reference. + */ + @Nullable + public Ref getOldRef() { + return oldRef; + } + + /** + * New peeled reference. + * + * @return the new reference; null if the command is deleting the reference. + */ + @Nullable + public Ref getNewRef() { + return newRef; + } + + @Override + public String toString() { + StringBuilder s = new StringBuilder(); + append(s, oldRef, "CREATE"); //$NON-NLS-1$ + s.append(' '); + append(s, newRef, "DELETE"); //$NON-NLS-1$ + s.append(' ').append(getRefName()); + s.append(' ').append(getResult()); + if (getMessage() != null) { + s.append(' ').append(getMessage()); + } + return s.toString(); + } + + private static void append(StringBuilder s, Ref r, String nullName) { + if (r == null) { + s.append(nullName); + } else if (r.isSymbolic()) { + s.append(r.getTarget().getName()); + } else { + ObjectId id = r.getObjectId(); + if (id != null) { + s.append(id.name()); + } + } + } + + /** + * Check the entry is consistent with either the old or the new ref. + * + * @param entry + * current entry; null if the entry does not exist. + * @return true if entry matches {@link #getOldRef()} or + * {@link #getNewRef()}; otherwise false. + */ + boolean checkRef(@Nullable DirCacheEntry entry) { + if (entry != null && entry.getRawMode() == 0) { + entry = null; + } + return check(entry, oldRef) || check(entry, newRef); + } + + private static boolean check(@Nullable DirCacheEntry cur, + @Nullable Ref exp) { + if (cur == null) { + // Does not exist, ok if oldRef does not exist. + return exp == null; + } else if (exp == null) { + // Expected to not exist, but currently exists, fail. + return false; + } + + if (exp.isSymbolic()) { + String dst = exp.getTarget().getName(); + return cur.getRawMode() == TYPE_SYMLINK + && cur.getObjectId().equals(symref(dst)); + } + + return cur.getRawMode() == TYPE_GITLINK + && cur.getObjectId().equals(exp.getObjectId()); + } + + static ObjectId symref(String s) { + @SuppressWarnings("resource") + ObjectInserter.Formatter fmt = new ObjectInserter.Formatter(); + return fmt.idFor(OBJ_BLOB, encode(s)); + } +} diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftree/RefTree.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftree/RefTree.java new file mode 100644 index 0000000000..237f7e9958 --- /dev/null +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftree/RefTree.java @@ -0,0 +1,410 @@ +/* + * Copyright (C) 2016, Google Inc. + * and other copyright owners as documented in the project's IP log. + * + * This program and the accompanying materials are made available + * under the terms of the Eclipse Distribution License v1.0 which + * accompanies this distribution, is reproduced below, and is + * available at http://www.eclipse.org/org/documents/edl-v10.php + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * - Neither the name of the Eclipse Foundation, Inc. nor the + * names of its contributors may be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +package org.eclipse.jgit.internal.storage.reftree; + +import static org.eclipse.jgit.lib.Constants.OBJ_BLOB; +import static org.eclipse.jgit.lib.Constants.R_REFS; +import static org.eclipse.jgit.lib.Constants.encode; +import static org.eclipse.jgit.lib.FileMode.GITLINK; +import static org.eclipse.jgit.lib.FileMode.SYMLINK; +import static org.eclipse.jgit.lib.FileMode.TYPE_GITLINK; +import static org.eclipse.jgit.lib.FileMode.TYPE_SYMLINK; +import static org.eclipse.jgit.lib.Ref.Storage.NEW; +import static org.eclipse.jgit.lib.Ref.Storage.PACKED; +import static org.eclipse.jgit.lib.RefDatabase.MAX_SYMBOLIC_REF_DEPTH; +import static org.eclipse.jgit.transport.ReceiveCommand.Result.LOCK_FAILURE; +import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED; +import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_OTHER_REASON; + +import java.io.IOException; +import java.util.Collection; +import java.util.HashMap; +import java.util.Map; + +import org.eclipse.jgit.annotations.Nullable; +import org.eclipse.jgit.dircache.DirCache; +import org.eclipse.jgit.dircache.DirCacheBuilder; +import org.eclipse.jgit.dircache.DirCacheEditor; +import org.eclipse.jgit.dircache.DirCacheEditor.DeletePath; +import org.eclipse.jgit.dircache.DirCacheEditor.PathEdit; +import org.eclipse.jgit.dircache.DirCacheEntry; +import org.eclipse.jgit.errors.CorruptObjectException; +import org.eclipse.jgit.errors.DirCacheNameConflictException; +import org.eclipse.jgit.errors.IncorrectObjectTypeException; +import org.eclipse.jgit.errors.MissingObjectException; +import org.eclipse.jgit.internal.JGitText; +import org.eclipse.jgit.lib.FileMode; +import org.eclipse.jgit.lib.ObjectId; +import org.eclipse.jgit.lib.ObjectIdRef; +import org.eclipse.jgit.lib.ObjectInserter; +import org.eclipse.jgit.lib.ObjectReader; +import org.eclipse.jgit.lib.Ref; +import org.eclipse.jgit.lib.SymbolicRef; +import org.eclipse.jgit.revwalk.RevTree; +import org.eclipse.jgit.util.RawParseUtils; + +/** + * Tree of references in the reference graph. + *

+ * The root corresponds to the {@code "refs/"} subdirectory, for example the + * default reference {@code "refs/heads/master"} is stored at path + * {@code "heads/master"} in a {@code RefTree}. + *

+ * Normal references are stored as {@link FileMode#GITLINK} tree entries. The + * ObjectId in the tree entry is the ObjectId the reference refers to. + *

+ * Symbolic references are stored as {@link FileMode#SYMLINK} entries, with the + * blob storing the name of the target reference. + *

+ * Annotated tags also store the peeled object using a {@code GITLINK} entry + * with the suffix "^{}", for example {@code "tags/v1.0"} stores + * the annotated tag object, while "tags/v1.0^{}" stores the commit + * the tag annotates. + *

+ * {@code HEAD} is a special case and stored as {@code "..HEAD"}. + */ +public class RefTree { + /** Suffix applied to GITLINK to indicate its the peeled value of a tag. */ + public static final String PEELED_SUFFIX = "^{}"; //$NON-NLS-1$ + static final String ROOT_DOTDOT = ".."; //$NON-NLS-1$ + + /** + * Create an empty reference tree. + * + * @return a new empty reference tree. + */ + public static RefTree newEmptyTree() { + return new RefTree(DirCache.newInCore()); + } + + /** + * Load a reference tree. + * + * @param reader + * reader to scan the reference tree with. + * @param tree + * the tree to read. + * @return the ref tree read from the commit. + * @throws IOException + * the repository cannot be accessed through the reader. + * @throws CorruptObjectException + * a tree object is corrupt and cannot be read. + * @throws IncorrectObjectTypeException + * a tree object wasn't actually a tree. + * @throws MissingObjectException + * a reference tree object doesn't exist. + */ + public static RefTree read(ObjectReader reader, RevTree tree) + throws MissingObjectException, IncorrectObjectTypeException, + CorruptObjectException, IOException { + return new RefTree(DirCache.read(reader, tree)); + } + + private DirCache contents; + private Map pendingBlobs; + + private RefTree(DirCache dc) { + this.contents = dc; + } + + /** + * Read one reference. + *

+ * References are always returned peeled ({@link Ref#isPeeled()} is true). + * If the reference points to an annotated tag, the returned reference will + * be peeled and contain {@link Ref#getPeeledObjectId()}. + *

+ * If the reference is a symbolic reference and the chain depth is less than + * {@link org.eclipse.jgit.lib.RefDatabase#MAX_SYMBOLIC_REF_DEPTH} the + * returned reference is resolved. If the chain depth is longer, the + * symbolic reference is returned without resolving. + * + * @param reader + * to access objects necessary to read the requested reference. + * @param name + * name of the reference to read. + * @return the reference; null if it does not exist. + * @throws IOException + * cannot read a symbolic reference target. + */ + @Nullable + public Ref exactRef(ObjectReader reader, String name) throws IOException { + Ref r = readRef(reader, name); + if (r == null) { + return null; + } else if (r.isSymbolic()) { + return resolve(reader, r, 0); + } + + DirCacheEntry p = contents.getEntry(peeledPath(name)); + if (p != null && p.getRawMode() == TYPE_GITLINK) { + return new ObjectIdRef.PeeledTag(PACKED, r.getName(), + r.getObjectId(), p.getObjectId()); + } + return r; + } + + private Ref readRef(ObjectReader reader, String name) throws IOException { + DirCacheEntry e = contents.getEntry(refPath(name)); + return e != null ? toRef(reader, e, name) : null; + } + + private Ref toRef(ObjectReader reader, DirCacheEntry e, String name) + throws IOException { + int mode = e.getRawMode(); + if (mode == TYPE_GITLINK) { + ObjectId id = e.getObjectId(); + return new ObjectIdRef.PeeledNonTag(PACKED, name, id); + } + + if (mode == TYPE_SYMLINK) { + ObjectId id = e.getObjectId(); + String n = pendingBlobs != null ? pendingBlobs.get(id) : null; + if (n == null) { + byte[] bin = reader.open(id, OBJ_BLOB).getCachedBytes(); + n = RawParseUtils.decode(bin); + } + Ref dst = new ObjectIdRef.Unpeeled(NEW, n, null); + return new SymbolicRef(name, dst); + } + + return null; // garbage file or something; not a reference. + } + + private Ref resolve(ObjectReader reader, Ref ref, int depth) + throws IOException { + if (ref.isSymbolic() && depth < MAX_SYMBOLIC_REF_DEPTH) { + Ref r = readRef(reader, ref.getTarget().getName()); + if (r == null) { + return ref; + } + Ref dst = resolve(reader, r, depth + 1); + return new SymbolicRef(ref.getName(), dst); + } + return ref; + } + + /** + * Attempt a batch of commands against this RefTree. + *

+ * The batch is applied atomically, either all commands apply at once, or + * they all reject and the RefTree is left unmodified. + *

+ * On success (when this method returns {@code true}) the command results + * are left as-is (probably {@code NOT_ATTEMPTED}). Result fields are set + * only when this method returns {@code false} to indicate failure. + * + * @param cmdList + * to apply. All commands should still have result NOT_ATTEMPTED. + * @return true if the commands applied; false if they were rejected. + */ + public boolean apply(Collection cmdList) { + try { + DirCacheEditor ed = contents.editor(); + for (Command cmd : cmdList) { + apply(ed, cmd); + } + ed.finish(); + return true; + } catch (DirCacheNameConflictException e) { + String r1 = refName(e.getPath1()); + String r2 = refName(e.getPath2()); + for (Command cmd : cmdList) { + if (r1.equals(cmd.getRefName()) + || r2.equals(cmd.getRefName())) { + cmd.setResult(LOCK_FAILURE); + break; + } + } + return abort(cmdList); + } catch (LockFailureException e) { + return abort(cmdList); + } + } + + private void apply(DirCacheEditor ed, final Command cmd) { + String path = refPath(cmd.getRefName()); + Ref oldRef = cmd.getOldRef(); + final Ref newRef = cmd.getNewRef(); + + if (newRef == null) { + checkRef(contents.getEntry(path), cmd); + ed.add(new DeletePath(path)); + cleanupPeeledRef(ed, oldRef); + return; + } + + if (newRef.isSymbolic()) { + final String dst = newRef.getTarget().getName(); + ed.add(new PathEdit(path) { + @Override + public void apply(DirCacheEntry ent) { + checkRef(ent, cmd); + ObjectId id = Command.symref(dst); + ent.setFileMode(SYMLINK); + ent.setObjectId(id); + if (pendingBlobs == null) { + pendingBlobs = new HashMap<>(4); + } + pendingBlobs.put(id, dst); + } + }.setReplace(false)); + cleanupPeeledRef(ed, oldRef); + return; + } + + ed.add(new PathEdit(path) { + @Override + public void apply(DirCacheEntry ent) { + checkRef(ent, cmd); + ent.setFileMode(GITLINK); + ent.setObjectId(newRef.getObjectId()); + } + }.setReplace(false)); + + if (newRef.getPeeledObjectId() != null) { + ed.add(new PathEdit(peeledPath(newRef.getName())) { + @Override + public void apply(DirCacheEntry ent) { + ent.setFileMode(GITLINK); + ent.setObjectId(newRef.getPeeledObjectId()); + } + }.setReplace(false)); + } else { + cleanupPeeledRef(ed, oldRef); + } + } + + private static void checkRef(@Nullable DirCacheEntry ent, Command cmd) { + if (!cmd.checkRef(ent)) { + cmd.setResult(LOCK_FAILURE); + throw new LockFailureException(); + } + } + + private static void cleanupPeeledRef(DirCacheEditor ed, Ref ref) { + if (ref != null && !ref.isSymbolic() + && (!ref.isPeeled() || ref.getPeeledObjectId() != null)) { + ed.add(new DeletePath(peeledPath(ref.getName()))); + } + } + + private static boolean abort(Iterable cmdList) { + for (Command cmd : cmdList) { + if (cmd.getResult() == NOT_ATTEMPTED) { + reject(cmd, JGitText.get().transactionAborted); + } + } + return false; + } + + private static void reject(Command cmd, String msg) { + cmd.setResult(REJECTED_OTHER_REASON, msg); + } + + /** + * Convert a path name in a RefTree to the reference name known by Git. + * + * @param path + * name read from the RefTree structure, for example + * {@code "heads/master"}. + * @return reference name for the path, {@code "refs/heads/master"}. + */ + public static String refName(String path) { + if (path.startsWith(ROOT_DOTDOT)) { + return path.substring(2); + } + return R_REFS + path; + } + + private static String refPath(String name) { + if (name.startsWith(R_REFS)) { + return name.substring(R_REFS.length()); + } + return ROOT_DOTDOT + name; + } + + private static String peeledPath(String name) { + return refPath(name) + PEELED_SUFFIX; + } + + /** + * Write this reference tree. + * + * @param inserter + * inserter to use when writing trees to the object database. + * Caller is responsible for flushing the inserter before trying + * to read the objects, or exposing them through a reference. + * @return the top level tree. + * @throws IOException + * a tree could not be written. + */ + public ObjectId writeTree(ObjectInserter inserter) throws IOException { + if (pendingBlobs != null) { + for (String s : pendingBlobs.values()) { + inserter.insert(OBJ_BLOB, encode(s)); + } + pendingBlobs = null; + } + return contents.writeTree(inserter); + } + + /** @return a deep copy of this RefTree. */ + public RefTree copy() { + RefTree r = new RefTree(DirCache.newInCore()); + DirCacheBuilder b = r.contents.builder(); + for (int i = 0; i < contents.getEntryCount(); i++) { + b.add(new DirCacheEntry(contents.getEntry(i))); + } + b.finish(); + if (pendingBlobs != null) { + r.pendingBlobs = new HashMap<>(pendingBlobs); + } + return r; + } + + private static class LockFailureException extends RuntimeException { + private static final long serialVersionUID = 1L; + } +} diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/RefDatabase.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/RefDatabase.java index 986666f2f4..c0c3862c8b 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/RefDatabase.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/RefDatabase.java @@ -82,8 +82,10 @@ public abstract class RefDatabase { *

* If the reference is nested deeper than this depth, the implementation * should either fail, or at least claim the reference does not exist. + * + * @since 4.2 */ - protected static final int MAX_SYMBOLIC_REF_DEPTH = 5; + public static final int MAX_SYMBOLIC_REF_DEPTH = 5; /** Magic value for {@link #getRefs(String)} to return all references. */ public static final String ALL = "";//$NON-NLS-1$ -- 2.39.5