* [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph"
@ 2009-03-13 14:35 Shawn O. Pearce
2009-03-13 14:49 ` Johannes Schindelin
2009-03-15 11:34 ` Robin Rosenberg
0 siblings, 2 replies; 8+ messages in thread
From: Shawn O. Pearce @ 2009-03-13 14:35 UTC (permalink / raw)
To: Robin Rosenberg; +Cc: git
This is a command line tool which can be used to import only
the commit graph of another Git repository, to help debug a
topology related bug, without actually needing a clone of the
problematic repository.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
I used this yesterday to obtain a DAG from someone's private
repository and recreate the same structure on my own system,
to debug why RevWalk was busted in their case.
Its only meant for debugging weird cases, I can't see many
uses of it. But now that its written, maybe we should add
it to the project and keep it around.
.../services/org.spearce.jgit.pgm.TextBuiltin | 1 +
.../org/spearce/jgit/pgm/RebuildCommitGraph.java | 276 ++++++++++++++++++++
2 files changed, 277 insertions(+), 0 deletions(-)
create mode 100644 org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java
diff --git a/org.spearce.jgit.pgm/src/META-INF/services/org.spearce.jgit.pgm.TextBuiltin b/org.spearce.jgit.pgm/src/META-INF/services/org.spearce.jgit.pgm.TextBuiltin
index 1ba29e6..9bba156 100644
--- a/org.spearce.jgit.pgm/src/META-INF/services/org.spearce.jgit.pgm.TextBuiltin
+++ b/org.spearce.jgit.pgm/src/META-INF/services/org.spearce.jgit.pgm.TextBuiltin
@@ -11,6 +11,7 @@ org.spearce.jgit.pgm.LsRemote
org.spearce.jgit.pgm.LsTree
org.spearce.jgit.pgm.MergeBase
org.spearce.jgit.pgm.Push
+org.spearce.jgit.pgm.RebuildCommitGraph
org.spearce.jgit.pgm.ReceivePack
org.spearce.jgit.pgm.RevList
org.spearce.jgit.pgm.Rm
diff --git a/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java
new file mode 100644
index 0000000..ccee997
--- /dev/null
+++ b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java
@@ -0,0 +1,276 @@
+/*
+ * Copyright (C) 2009, Google Inc.
+ *
+ * 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 Git Development Community 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.spearce.jgit.pgm;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.Map;
+
+import org.kohsuke.args4j.Argument;
+import org.spearce.jgit.errors.MissingObjectException;
+import org.spearce.jgit.errors.ObjectWritingException;
+import org.spearce.jgit.lib.Commit;
+import org.spearce.jgit.lib.Constants;
+import org.spearce.jgit.lib.LockFile;
+import org.spearce.jgit.lib.ObjectId;
+import org.spearce.jgit.lib.ObjectWriter;
+import org.spearce.jgit.lib.PersonIdent;
+import org.spearce.jgit.lib.ProgressMonitor;
+import org.spearce.jgit.lib.Ref;
+import org.spearce.jgit.lib.RefUpdate;
+import org.spearce.jgit.lib.RefWriter;
+import org.spearce.jgit.lib.TextProgressMonitor;
+import org.spearce.jgit.lib.Tree;
+import org.spearce.jgit.revwalk.RevWalk;
+
+/**
+ * Recreates a repository from another one's commit graph.
+ * <p>
+ * <b>Do not run this on a repository unless you want to destroy it.</b>
+ * <p>
+ * To create the input files, in the source repository use:
+ *
+ * <pre>
+ * git for-each-ref >in.refs
+ * git log --all '--pretty=format:%H %ct %P' >in.dag
+ * </pre>
+ * <p>
+ * Run the rebuild in either an empty repository, or a clone of the source. Any
+ * missing commits (which might be the entire graph) will be created. All refs
+ * will be modified to match the input exactly, which means some refs may be
+ * deleted from the current repository.
+ * <p>
+ */
+class RebuildCommitGraph extends TextBuiltin {
+ @Argument(index = 0, required = true, metaVar = "REFS", usage = "for-each-ref output")
+ File refList;
+
+ @Argument(index = 1, required = true, metaVar = "DAG", usage = "log --all '--pretty=format:%H %ct %P' output")
+ File graph;
+
+ private final ProgressMonitor pm = new TextProgressMonitor();
+
+ private Map<ObjectId, ObjectId> rewrites = new HashMap<ObjectId, ObjectId>();
+
+ @Override
+ protected void run() throws Exception {
+ recreateCommitGraph();
+ detachHead();
+ deleteAllRefs();
+ recreateRefs();
+ }
+
+ private void recreateCommitGraph() throws IOException {
+ final RevWalk rw = new RevWalk(db);
+ final Map<ObjectId, ToRewrite> toRewrite = new HashMap<ObjectId, ToRewrite>();
+ List<ToRewrite> queue = new ArrayList<ToRewrite>();
+ final BufferedReader br = new BufferedReader(new InputStreamReader(
+ new FileInputStream(graph), Constants.CHARSET));
+ try {
+ String line;
+ while ((line = br.readLine()) != null) {
+ final String[] parts = line.split("[ \t]{1,}");
+ final ObjectId oldId = ObjectId.fromString(parts[0]);
+ try {
+ rw.parseCommit(oldId);
+ // We have it already. Don't rewrite it.
+ continue;
+ } catch (MissingObjectException mue) {
+ // Fall through and rewrite it.
+ }
+
+ final long time = Long.parseLong(parts[1]) * 1000L;
+ final ObjectId[] parents = new ObjectId[parts.length - 2];
+ for (int i = 0; i < parents.length; i++) {
+ parents[i] = ObjectId.fromString(parts[2 + i]);
+ }
+
+ final ToRewrite t = new ToRewrite(oldId, time, parents);
+ toRewrite.put(oldId, t);
+ queue.add(t);
+ }
+ } finally {
+ br.close();
+ }
+
+ pm.beginTask("Rewriting commits", queue.size());
+ final ObjectWriter ow = new ObjectWriter(db);
+ final ObjectId emptyTree = ow.writeTree(new Tree(db));
+ final PersonIdent me = new PersonIdent("jgit rebuild-commitgraph",
+ "rebuild-commitgraph@localhost");
+ while (!queue.isEmpty()) {
+ final ListIterator<ToRewrite> itr = queue
+ .listIterator(queue.size());
+ queue = new ArrayList<ToRewrite>();
+ REWRITE: while (itr.hasPrevious()) {
+ final ToRewrite t = itr.previous();
+ final ObjectId[] newParents = new ObjectId[t.oldParents.length];
+ for (int k = 0; k < t.oldParents.length; k++) {
+ final ToRewrite p = toRewrite.get(t.oldParents[k]);
+ if (p != null) {
+ if (p.newId == null) {
+ // Must defer until after the parent is rewritten.
+ queue.add(t);
+ continue REWRITE;
+ } else {
+ newParents[k] = p.newId;
+ }
+ } else {
+ // We have the old parent object. Use it.
+ //
+ newParents[k] = t.oldParents[k];
+ }
+ }
+
+ final Commit newc = new Commit(db);
+ newc.setTreeId(emptyTree);
+ newc.setAuthor(new PersonIdent(me, new Date(t.commitTime)));
+ newc.setCommitter(newc.getAuthor());
+ newc.setParentIds(newParents);
+ newc.setMessage("ORIGINAL " + t.oldId.name() + "\n");
+ t.newId = ow.writeCommit(newc);
+ rewrites.put(t.oldId, t.newId);
+ pm.update(1);
+ }
+ }
+ pm.endTask();
+ }
+
+ private static class ToRewrite {
+ final ObjectId oldId;
+
+ final long commitTime;
+
+ final ObjectId[] oldParents;
+
+ ObjectId newId;
+
+ ToRewrite(final ObjectId o, final long t, final ObjectId[] p) {
+ oldId = o;
+ commitTime = t;
+ oldParents = p;
+ }
+ }
+
+ private void detachHead() throws IOException {
+ final String head = db.getFullBranch();
+ final ObjectId id = db.resolve(Constants.HEAD);
+ if (!ObjectId.isId(head) && id != null) {
+ final LockFile lf;
+ lf = new LockFile(new File(db.getDirectory(), Constants.HEAD));
+ if (!lf.lock())
+ throw new IOException("Cannot lock HEAD");
+ lf.write(id);
+ if (!lf.commit())
+ throw new IOException("Cannot deatch HEAD");
+ }
+ }
+
+ private void deleteAllRefs() throws Exception {
+ final RevWalk rw = new RevWalk(db);
+ for (final Ref r : db.getAllRefs().values()) {
+ if (Constants.HEAD.equals(r.getName()))
+ continue;
+ final RefUpdate u = db.updateRef(r.getName());
+ u.setForceUpdate(true);
+ u.delete(rw);
+ }
+ }
+
+ private void recreateRefs() throws Exception {
+ final Map<String, Ref> refs = computeNewRefs();
+ new RefWriter(refs.values()) {
+ @Override
+ protected void writeFile(final String name, final byte[] content)
+ throws IOException {
+ final File file = new File(db.getDirectory(), name);
+ final LockFile lck = new LockFile(file);
+ if (!lck.lock())
+ throw new ObjectWritingException("Can't write " + file);
+ try {
+ lck.write(content);
+ } catch (IOException ioe) {
+ throw new ObjectWritingException("Can't write " + file);
+ }
+ if (!lck.commit())
+ throw new ObjectWritingException("Can't write " + file);
+ }
+ }.writePackedRefs();
+ }
+
+ private Map<String, Ref> computeNewRefs() throws IOException {
+ final RevWalk rw = new RevWalk(db);
+ final Map<String, Ref> refs = new HashMap<String, Ref>();
+ final BufferedReader br = new BufferedReader(new InputStreamReader(
+ new FileInputStream(refList), Constants.CHARSET));
+ try {
+ String line;
+ while ((line = br.readLine()) != null) {
+ final String[] parts = line.split("[ \t]{1,}");
+ final ObjectId origId = ObjectId.fromString(parts[0]);
+ final String type = parts[1];
+ final String name = parts[2];
+
+ ObjectId id = rewrites.get(origId);
+ if (id == null)
+ id = origId;
+ try {
+ rw.parseAny(id);
+ } catch (MissingObjectException mue) {
+ if (!Constants.TYPE_COMMIT.equals(type)) {
+ System.err.println("skipping " + type + " " + name);
+ continue;
+ }
+ throw new MissingObjectException(id, type);
+ }
+ refs.put(name, new Ref(Ref.Storage.PACKED, name, id));
+ }
+ } finally {
+ br.close();
+ }
+ return refs;
+ }
+}
--
1.6.2.288.gc3f22
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph"
2009-03-13 14:35 [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph" Shawn O. Pearce
@ 2009-03-13 14:49 ` Johannes Schindelin
2009-03-13 14:52 ` Shawn O. Pearce
2009-03-15 11:34 ` Robin Rosenberg
1 sibling, 1 reply; 8+ messages in thread
From: Johannes Schindelin @ 2009-03-13 14:49 UTC (permalink / raw)
To: Shawn O. Pearce; +Cc: Robin Rosenberg, git
Hi,
On Fri, 13 Mar 2009, Shawn O. Pearce wrote:
> This is a command line tool which can be used to import only
> the commit graph of another Git repository, to help debug a
> topology related bug, without actually needing a clone of the
> problematic repository.
>
> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
> ---
>
> I used this yesterday to obtain a DAG from someone's private
> repository and recreate the same structure on my own system,
> to debug why RevWalk was busted in their case.
Heh:
http://repo.or.cz/w/git/dscho.git?a=blob;f=my-fake-history.sh;h=e108ce99a5ebd75230c3cfc56b88d9769fec8bc1;hb=master
Ciao,
Dscho
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph"
2009-03-13 14:49 ` Johannes Schindelin
@ 2009-03-13 14:52 ` Shawn O. Pearce
0 siblings, 0 replies; 8+ messages in thread
From: Shawn O. Pearce @ 2009-03-13 14:52 UTC (permalink / raw)
To: Johannes Schindelin; +Cc: Robin Rosenberg, git
Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> On Fri, 13 Mar 2009, Shawn O. Pearce wrote:
>
> > This is a command line tool which can be used to import only
> > the commit graph of another Git repository, to help debug a
> > topology related bug, without actually needing a clone of the
> > problematic repository.
> >
> > Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
> > ---
> >
> > I used this yesterday to obtain a DAG from someone's private
> > repository and recreate the same structure on my own system,
> > to debug why RevWalk was busted in their case.
>
> Heh:
>
> http://repo.or.cz/w/git/dscho.git?a=blob;f=my-fake-history.sh;h=e108ce99a5ebd75230c3cfc56b88d9769fec8bc1;hb=master
Heh. I knew both you and Nico have written something like this in
the past, but I couldn't find it.
Your script is almost what I needed. But I also needed to force
GIT_COMMITTER_DATE to match the timestamp, as I suspected the commit
times had something to do with the problem I was seeing.
I also whack the entire ref space to match the source repository,
which mattered because I was trying to debug:
git rev-list $insha1 --not --all
in JGit...
--
Shawn.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph"
2009-03-13 14:35 [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph" Shawn O. Pearce
2009-03-13 14:49 ` Johannes Schindelin
@ 2009-03-15 11:34 ` Robin Rosenberg
2009-03-16 14:44 ` Shawn O. Pearce
1 sibling, 1 reply; 8+ messages in thread
From: Robin Rosenberg @ 2009-03-15 11:34 UTC (permalink / raw)
To: Shawn O. Pearce; +Cc: git
I'd hate to put such a dangerous thing in the list of normal tools. If the user
want to shoot him/her-self in the foot they should get a license first.
-- robin
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph"
2009-03-15 11:34 ` Robin Rosenberg
@ 2009-03-16 14:44 ` Shawn O. Pearce
2009-03-16 20:09 ` Robin Rosenberg
0 siblings, 1 reply; 8+ messages in thread
From: Shawn O. Pearce @ 2009-03-16 14:44 UTC (permalink / raw)
To: Robin Rosenberg; +Cc: git
Robin Rosenberg <robin.rosenberg@dewire.com> wrote:
>
> I'd hate to put such a dangerous thing in the list of normal tools. If the user
> want to shoot him/her-self in the foot they should get a license first.
How about squashing this in?
diff --git a/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java
index ccee997..cc23438 100644
--- a/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java
+++ b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java
@@ -50,6 +50,7 @@
import java.util.Map;
import org.kohsuke.args4j.Argument;
+import org.kohsuke.args4j.Option;
import org.spearce.jgit.errors.MissingObjectException;
import org.spearce.jgit.errors.ObjectWritingException;
import org.spearce.jgit.lib.Commit;
@@ -85,6 +86,11 @@
* <p>
*/
class RebuildCommitGraph extends TextBuiltin {
+ private final String REALLY = "--destroy-this-repository";
+
+ @Option(name = REALLY, usage = "approve destruction of repository")
+ boolean really;
+
@Argument(index = 0, required = true, metaVar = "REFS", usage = "for-each-ref output")
File refList;
@@ -97,6 +103,30 @@
@Override
protected void run() throws Exception {
+ if (!really && !db.getAllRefs().isEmpty()) {
+ final StringBuilder m = new StringBuilder();
+ m.append("fatal: ");
+ m.append("This program will destroy the repository:");
+ m.append("\n");
+ m.append("fatal:\n");
+ m.append("fatal: ");
+ m.append(db.getDirectory().getAbsolutePath());
+ m.append("\n");
+ m.append("fatal:\n");
+ m.append("fatal: ");
+ m.append("To continue, add ");
+ m.append(REALLY);
+ m.append(" to the command line");
+ m.append("\n");
+ m.append("fatal:");
+ System.err.println(m);
+ throw die("Need approval to destroy current repository");
+ }
+ if (!refList.isFile())
+ throw die("no such file: " + refList.getPath());
+ if (!graph.isFile())
+ throw die("no such file: " + graph.getPath());
+
recreateCommitGraph();
detachHead();
deleteAllRefs();
--
Shawn.
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph"
2009-03-16 14:44 ` Shawn O. Pearce
@ 2009-03-16 20:09 ` Robin Rosenberg
2009-03-16 20:13 ` Shawn O. Pearce
0 siblings, 1 reply; 8+ messages in thread
From: Robin Rosenberg @ 2009-03-16 20:09 UTC (permalink / raw)
To: Shawn O. Pearce; +Cc: git
måndag 16 mars 2009 15:44:50 skrev "Shawn O. Pearce" <spearce@spearce.org>:
> Robin Rosenberg <robin.rosenberg@dewire.com> wrote:
> >
> > I'd hate to put such a dangerous thing in the list of normal tools. If the user
> > want to shoot him/her-self in the foot they should get a license first.
>
> How about squashing this in?
Does it have to be a utility accessible through the pgm interface? Why not
just run ut as java org.spearce.jgit.pgm.debug.RebuildCommitGraph ?
>
> diff --git a/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java
> index ccee997..cc23438 100644
> --- a/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java
> +++ b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/RebuildCommitGraph.java
> @@ -50,6 +50,7 @@
> import java.util.Map;
>
> import org.kohsuke.args4j.Argument;
> +import org.kohsuke.args4j.Option;
> import org.spearce.jgit.errors.MissingObjectException;
> import org.spearce.jgit.errors.ObjectWritingException;
> import org.spearce.jgit.lib.Commit;
> @@ -85,6 +86,11 @@
> * <p>
> */
> class RebuildCommitGraph extends TextBuiltin {
> + private final String REALLY = "--destroy-this-repository";
> +
> + @Option(name = REALLY, usage = "approve destruction of repository")
> + boolean really;
> +
> @Argument(index = 0, required = true, metaVar = "REFS", usage = "for-each-ref output")
> File refList;
>
> @@ -97,6 +103,30 @@
>
> @Override
> protected void run() throws Exception {
> + if (!really && !db.getAllRefs().isEmpty()) {
> + final StringBuilder m = new StringBuilder();
> + m.append("fatal: ");
> + m.append("This program will destroy the repository:");
> + m.append("\n");
> + m.append("fatal:\n");
> + m.append("fatal: ");
> + m.append(db.getDirectory().getAbsolutePath());
> + m.append("\n");
> + m.append("fatal:\n");
> + m.append("fatal: ");
> + m.append("To continue, add ");
> + m.append(REALLY);
> + m.append(" to the command line");
> + m.append("\n");
> + m.append("fatal:");
> + System.err.println(m);
> + throw die("Need approval to destroy current repository");
What's wrong with old fashioned '+' ? (which just translated to exactly this series
of StringBuilder calls anyway?
> + }
> + if (!refList.isFile())
> + throw die("no such file: " + refList.getPath());
> + if (!graph.isFile())
> + throw die("no such file: " + graph.getPath());
> +
> recreateCommitGraph();
> detachHead();
> deleteAllRefs();
-- robin
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph"
2009-03-16 20:09 ` Robin Rosenberg
@ 2009-03-16 20:13 ` Shawn O. Pearce
2009-03-16 23:58 ` [JGIT PATCH v3] Create a debugging tool "jgit debug-rebuild-commitgraph" Shawn O. Pearce
0 siblings, 1 reply; 8+ messages in thread
From: Shawn O. Pearce @ 2009-03-16 20:13 UTC (permalink / raw)
To: Robin Rosenberg; +Cc: git
Robin Rosenberg <robin.rosenberg.lists@dewire.com> wrote:
> måndag 16 mars 2009 15:44:50 skrev "Shawn O. Pearce" <spearce@spearce.org>:
> > Robin Rosenberg <robin.rosenberg@dewire.com> wrote:
> > >
> > > I'd hate to put such a dangerous thing in the list of normal tools. If the user
> > > want to shoot him/her-self in the foot they should get a license first.
> >
> > How about squashing this in?
>
> Does it have to be a utility accessible through the pgm interface? Why not
> just run ut as java org.spearce.jgit.pgm.debug.RebuildCommitGraph ?
Yea, that's fine too. Then its "debug-rebuildcommitgraph" I think,
but that's still a reasonable name for it.
> > @Override
> > protected void run() throws Exception {
> > + if (!really && !db.getAllRefs().isEmpty()) {
> > + final StringBuilder m = new StringBuilder();
> > + m.append("fatal: ");
...
> > + System.err.println(m);
> > + throw die("Need approval to destroy current repository");
>
> What's wrong with old fashioned '+' ? (which just translated to exactly this series
> of StringBuilder calls anyway?
Nothing, other than formatting. + line wraps somewhat ugly sometimes
under the Eclipse formatter. Using StringBuilder with one append per
line and a short name for the StringBuilder variable makes it easier
to format.
--
Shawn.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [JGIT PATCH v3] Create a debugging tool "jgit debug-rebuild-commitgraph"
2009-03-16 20:13 ` Shawn O. Pearce
@ 2009-03-16 23:58 ` Shawn O. Pearce
0 siblings, 0 replies; 8+ messages in thread
From: Shawn O. Pearce @ 2009-03-16 23:58 UTC (permalink / raw)
To: Robin Rosenberg; +Cc: git
This is a command line tool which can be used to import only
the commit graph of another Git repository, to help debug a
topology related bug, without actually needing a clone of the
problematic repository.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
Robin Rosenberg <robin.rosenberg@dewire.com> wrote:
> Does it have to be a utility accessible through the pgm interface? Why not
> just run ut as java org.spearce.jgit.pgm.debug.RebuildCommitGraph ?
Moved. Prior squash request was also squashed.
.../services/org.spearce.jgit.pgm.TextBuiltin | 1 +
.../spearce/jgit/pgm/debug/RebuildCommitGraph.java | 307 ++++++++++++++++++++
2 files changed, 308 insertions(+), 0 deletions(-)
create mode 100644 org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/debug/RebuildCommitGraph.java
diff --git a/org.spearce.jgit.pgm/src/META-INF/services/org.spearce.jgit.pgm.TextBuiltin b/org.spearce.jgit.pgm/src/META-INF/services/org.spearce.jgit.pgm.TextBuiltin
index 1ba29e6..2fe6612 100644
--- a/org.spearce.jgit.pgm/src/META-INF/services/org.spearce.jgit.pgm.TextBuiltin
+++ b/org.spearce.jgit.pgm/src/META-INF/services/org.spearce.jgit.pgm.TextBuiltin
@@ -21,6 +21,7 @@ org.spearce.jgit.pgm.Version
org.spearce.jgit.pgm.debug.MakeCacheTree
org.spearce.jgit.pgm.debug.ReadDirCache
+org.spearce.jgit.pgm.debug.RebuildCommitGraph
org.spearce.jgit.pgm.debug.ShowCacheTree
org.spearce.jgit.pgm.debug.ShowCommands
org.spearce.jgit.pgm.debug.ShowDirCache
diff --git a/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/debug/RebuildCommitGraph.java b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/debug/RebuildCommitGraph.java
new file mode 100644
index 0000000..63e189c
--- /dev/null
+++ b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/debug/RebuildCommitGraph.java
@@ -0,0 +1,307 @@
+/*
+ * Copyright (C) 2009, Google Inc.
+ *
+ * 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 Git Development Community 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.spearce.jgit.pgm.debug;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.Map;
+
+import org.kohsuke.args4j.Argument;
+import org.kohsuke.args4j.Option;
+import org.spearce.jgit.errors.MissingObjectException;
+import org.spearce.jgit.errors.ObjectWritingException;
+import org.spearce.jgit.lib.Commit;
+import org.spearce.jgit.lib.Constants;
+import org.spearce.jgit.lib.LockFile;
+import org.spearce.jgit.lib.ObjectId;
+import org.spearce.jgit.lib.ObjectWriter;
+import org.spearce.jgit.lib.PersonIdent;
+import org.spearce.jgit.lib.ProgressMonitor;
+import org.spearce.jgit.lib.Ref;
+import org.spearce.jgit.lib.RefUpdate;
+import org.spearce.jgit.lib.RefWriter;
+import org.spearce.jgit.lib.TextProgressMonitor;
+import org.spearce.jgit.lib.Tree;
+import org.spearce.jgit.pgm.TextBuiltin;
+import org.spearce.jgit.revwalk.RevWalk;
+
+/**
+ * Recreates a repository from another one's commit graph.
+ * <p>
+ * <b>Do not run this on a repository unless you want to destroy it.</b>
+ * <p>
+ * To create the input files, in the source repository use:
+ *
+ * <pre>
+ * git for-each-ref >in.refs
+ * git log --all '--pretty=format:%H %ct %P' >in.dag
+ * </pre>
+ * <p>
+ * Run the rebuild in either an empty repository, or a clone of the source. Any
+ * missing commits (which might be the entire graph) will be created. All refs
+ * will be modified to match the input exactly, which means some refs may be
+ * deleted from the current repository.
+ * <p>
+ */
+class RebuildCommitGraph extends TextBuiltin {
+ private final String REALLY = "--destroy-this-repository";
+
+ @Option(name = REALLY, usage = "approve destruction of repository")
+ boolean really;
+
+ @Argument(index = 0, required = true, metaVar = "REFS", usage = "for-each-ref output")
+ File refList;
+
+ @Argument(index = 1, required = true, metaVar = "DAG", usage = "log --all '--pretty=format:%H %ct %P' output")
+ File graph;
+
+ private final ProgressMonitor pm = new TextProgressMonitor();
+
+ private Map<ObjectId, ObjectId> rewrites = new HashMap<ObjectId, ObjectId>();
+
+ @Override
+ protected void run() throws Exception {
+ if (!really && !db.getAllRefs().isEmpty()) {
+ final StringBuilder m = new StringBuilder();
+ m.append("fatal: ");
+ m.append("This program will destroy the repository:");
+ m.append("\n");
+ m.append("fatal:\n");
+ m.append("fatal: ");
+ m.append(db.getDirectory().getAbsolutePath());
+ m.append("\n");
+ m.append("fatal:\n");
+ m.append("fatal: ");
+ m.append("To continue, add ");
+ m.append(REALLY);
+ m.append(" to the command line");
+ m.append("\n");
+ m.append("fatal:");
+ System.err.println(m);
+ throw die("Need approval to destroy current repository");
+ }
+ if (!refList.isFile())
+ throw die("no such file: " + refList.getPath());
+ if (!graph.isFile())
+ throw die("no such file: " + graph.getPath());
+
+ recreateCommitGraph();
+ detachHead();
+ deleteAllRefs();
+ recreateRefs();
+ }
+
+ private void recreateCommitGraph() throws IOException {
+ final RevWalk rw = new RevWalk(db);
+ final Map<ObjectId, ToRewrite> toRewrite = new HashMap<ObjectId, ToRewrite>();
+ List<ToRewrite> queue = new ArrayList<ToRewrite>();
+ final BufferedReader br = new BufferedReader(new InputStreamReader(
+ new FileInputStream(graph), Constants.CHARSET));
+ try {
+ String line;
+ while ((line = br.readLine()) != null) {
+ final String[] parts = line.split("[ \t]{1,}");
+ final ObjectId oldId = ObjectId.fromString(parts[0]);
+ try {
+ rw.parseCommit(oldId);
+ // We have it already. Don't rewrite it.
+ continue;
+ } catch (MissingObjectException mue) {
+ // Fall through and rewrite it.
+ }
+
+ final long time = Long.parseLong(parts[1]) * 1000L;
+ final ObjectId[] parents = new ObjectId[parts.length - 2];
+ for (int i = 0; i < parents.length; i++) {
+ parents[i] = ObjectId.fromString(parts[2 + i]);
+ }
+
+ final ToRewrite t = new ToRewrite(oldId, time, parents);
+ toRewrite.put(oldId, t);
+ queue.add(t);
+ }
+ } finally {
+ br.close();
+ }
+
+ pm.beginTask("Rewriting commits", queue.size());
+ final ObjectWriter ow = new ObjectWriter(db);
+ final ObjectId emptyTree = ow.writeTree(new Tree(db));
+ final PersonIdent me = new PersonIdent("jgit rebuild-commitgraph",
+ "rebuild-commitgraph@localhost");
+ while (!queue.isEmpty()) {
+ final ListIterator<ToRewrite> itr = queue
+ .listIterator(queue.size());
+ queue = new ArrayList<ToRewrite>();
+ REWRITE: while (itr.hasPrevious()) {
+ final ToRewrite t = itr.previous();
+ final ObjectId[] newParents = new ObjectId[t.oldParents.length];
+ for (int k = 0; k < t.oldParents.length; k++) {
+ final ToRewrite p = toRewrite.get(t.oldParents[k]);
+ if (p != null) {
+ if (p.newId == null) {
+ // Must defer until after the parent is rewritten.
+ queue.add(t);
+ continue REWRITE;
+ } else {
+ newParents[k] = p.newId;
+ }
+ } else {
+ // We have the old parent object. Use it.
+ //
+ newParents[k] = t.oldParents[k];
+ }
+ }
+
+ final Commit newc = new Commit(db);
+ newc.setTreeId(emptyTree);
+ newc.setAuthor(new PersonIdent(me, new Date(t.commitTime)));
+ newc.setCommitter(newc.getAuthor());
+ newc.setParentIds(newParents);
+ newc.setMessage("ORIGINAL " + t.oldId.name() + "\n");
+ t.newId = ow.writeCommit(newc);
+ rewrites.put(t.oldId, t.newId);
+ pm.update(1);
+ }
+ }
+ pm.endTask();
+ }
+
+ private static class ToRewrite {
+ final ObjectId oldId;
+
+ final long commitTime;
+
+ final ObjectId[] oldParents;
+
+ ObjectId newId;
+
+ ToRewrite(final ObjectId o, final long t, final ObjectId[] p) {
+ oldId = o;
+ commitTime = t;
+ oldParents = p;
+ }
+ }
+
+ private void detachHead() throws IOException {
+ final String head = db.getFullBranch();
+ final ObjectId id = db.resolve(Constants.HEAD);
+ if (!ObjectId.isId(head) && id != null) {
+ final LockFile lf;
+ lf = new LockFile(new File(db.getDirectory(), Constants.HEAD));
+ if (!lf.lock())
+ throw new IOException("Cannot lock HEAD");
+ lf.write(id);
+ if (!lf.commit())
+ throw new IOException("Cannot deatch HEAD");
+ }
+ }
+
+ private void deleteAllRefs() throws Exception {
+ final RevWalk rw = new RevWalk(db);
+ for (final Ref r : db.getAllRefs().values()) {
+ if (Constants.HEAD.equals(r.getName()))
+ continue;
+ final RefUpdate u = db.updateRef(r.getName());
+ u.setForceUpdate(true);
+ u.delete(rw);
+ }
+ }
+
+ private void recreateRefs() throws Exception {
+ final Map<String, Ref> refs = computeNewRefs();
+ new RefWriter(refs.values()) {
+ @Override
+ protected void writeFile(final String name, final byte[] content)
+ throws IOException {
+ final File file = new File(db.getDirectory(), name);
+ final LockFile lck = new LockFile(file);
+ if (!lck.lock())
+ throw new ObjectWritingException("Can't write " + file);
+ try {
+ lck.write(content);
+ } catch (IOException ioe) {
+ throw new ObjectWritingException("Can't write " + file);
+ }
+ if (!lck.commit())
+ throw new ObjectWritingException("Can't write " + file);
+ }
+ }.writePackedRefs();
+ }
+
+ private Map<String, Ref> computeNewRefs() throws IOException {
+ final RevWalk rw = new RevWalk(db);
+ final Map<String, Ref> refs = new HashMap<String, Ref>();
+ final BufferedReader br = new BufferedReader(new InputStreamReader(
+ new FileInputStream(refList), Constants.CHARSET));
+ try {
+ String line;
+ while ((line = br.readLine()) != null) {
+ final String[] parts = line.split("[ \t]{1,}");
+ final ObjectId origId = ObjectId.fromString(parts[0]);
+ final String type = parts[1];
+ final String name = parts[2];
+
+ ObjectId id = rewrites.get(origId);
+ if (id == null)
+ id = origId;
+ try {
+ rw.parseAny(id);
+ } catch (MissingObjectException mue) {
+ if (!Constants.TYPE_COMMIT.equals(type)) {
+ System.err.println("skipping " + type + " " + name);
+ continue;
+ }
+ throw new MissingObjectException(id, type);
+ }
+ refs.put(name, new Ref(Ref.Storage.PACKED, name, id));
+ }
+ } finally {
+ br.close();
+ }
+ return refs;
+ }
+}
--
1.6.2.1.286.g8173
^ permalink raw reply related [flat|nested] 8+ messages in thread
end of thread, other threads:[~2009-03-17 0:00 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-03-13 14:35 [JGIT PATCH] Create a debugging tool "jgit rebuild-commitgraph" Shawn O. Pearce
2009-03-13 14:49 ` Johannes Schindelin
2009-03-13 14:52 ` Shawn O. Pearce
2009-03-15 11:34 ` Robin Rosenberg
2009-03-16 14:44 ` Shawn O. Pearce
2009-03-16 20:09 ` Robin Rosenberg
2009-03-16 20:13 ` Shawn O. Pearce
2009-03-16 23:58 ` [JGIT PATCH v3] Create a debugging tool "jgit debug-rebuild-commitgraph" Shawn O. Pearce
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