[Xapian-discuss] Re: 1.0 news, and a call for testing

[Fabrice Colin]

On 5/6/07, Richard Boulton <richard at lemurconsulting.com> wrote:
> Richard Boulton wrote:
> > The lock file shouldn't be removed, because flint uses higher level
> > file-locking, rather than just testing for the presence of the lock
> > file.  The lock on it should be released, though, when the Writable
> > database fails to be opened, so the overwrite step should work.
> >
> > I'll try and write a test case to simulate this situation, and reproduce
> > it here.
>
> I've added a test to Xapian for this situation, but it doesn't reproduce
> the problem.  If you could submit a working piece of code that fails in
> this way, that would be very helpful.
>
Thanks for implementing DatabaseVersionError. It works as expected in
the snapshot I tried (svn8484).

As for the locking problem I described, I quickly hacked omindex to try
and overwrite the database if a format error is detected :

--- omindex.cc_bak      2007-05-07 20:09:00.000000000 +0800
+++ omindex.cc  2007-05-07 21:35:11.000000000 +0800
@@ -836,12 +836,14 @@
     try {
        if (!overwrite) {
            db = Xapian::WritableDatabase(dbpath, Xapian::DB_CREATE_OR_OPEN);
+            cout << "Opened database" << endl;
            if (!skip_duplicates) {
                // + 1 so that db.get_lastdocid() is a valid subscript.
                updated.resize(db.get_lastdocid() + 1);
            }
        } else {
            db = Xapian::WritableDatabase(dbpath,
Xapian::DB_CREATE_OR_OVERWRITE);
+            cout << "Opened database" << endl;
        }

        indexer.set_stemmer(stemmer);
@@ -861,6 +863,16 @@
        db.flush();
        // cout << "\n\nNow we have " << db.get_doccount() << " documents.\n";
        exitcode = 0;
+    } catch (const Xapian::DatabaseVersionError &e) {
+       cout << "Database Version Exception: " << e.get_msg() << endl;
+       try
+       {
+               if (!overwrite) {
+                   db = Xapian::WritableDatabase(dbpath,
Xapian::DB_CREATE_OR_OVERWRITE);
+               }
+       } catch (const Xapian::Error &ee) {
+               cout << "Another Exception: " << ee.get_msg() << endl;
+       }
     } catch (const Xapian::Error &e) {
        cout << "Exception: " << e.get_msg() << endl;
     } catch (const string &s) {

If I run the resulting omindex against an old database I have, with :

$ ./omindex --db ~/.pinot/daemon_bak --url
file:///home/fabrice/Documents/UniversalCharsetDetection.doc
/home/fabrice/Documents/UniversalCharsetDetection.doc

I get this output :

"
Database Version Exception: Flint version file
/home/fabrice/.pinot/daemon_bak/iamflint is version 200506110 but I
only understand 200704230
Another Exception: Unable to acquire database write lock on
/home/fabrice/.pinot/daemon_bak: already locked
"

Is this enough to point in the right direction ? Let me know if you need more
information.

Fabrice