On Wed, Jun 25, 2014 at 5:46 PM, Ivan Zhakov <ivan_at_visualsvn.com> wrote:
> On 25 June 2014 19:24, Stefan Fuhrmann <stefan.fuhrmann_at_wandisco.com>
> wrote:
> > On Wed, Jun 25, 2014 at 4:57 PM, Ivan Zhakov <ivan_at_visualsvn.com> wrote:
> >>
> >> On 21 June 2014 17:15, <stefan2_at_apache.org> wrote:
> >> > Author: stefan2
> >> > Date: Sat Jun 21 15:15:30 2014
> >> > New Revision: 1604421
> >> >
> >> > URL: http://svn.apache.org/r1604421
> >> > Log:
> >> > Append index data to the rev data file instead of using separate
> files.
> >> >
> >> > This gives unpacked FSFS format 7 similar I/O characteristics and disk
> >> > space usage as earlier formats. It also eliminates the need for
> retries
> >> > after a potential background pack run because each file is now always
> >> > consistent with itself (earlier, data or index files might already
> have
> >> > been deleted while the respective other was still valid). Overall,
> >> > most of this patch is removing code necessary to handle separate
> files.
> >> >
> >> > The new file format is simple:
> >> >
> >> > <rep data><l2p index><p2l index><footer><footer length>
> >> >
> >> > with the first three being identical what we had before. <footer
> length>
> >> > is a single byte giving the length of the preceding footer, so it's
> >> > easier to extract than the pre-f7 rev trailer and there is only one
> >> > per pack / rev file.
> >> >
> >> [..]
> >>
> >>
> >> >Modified: subversion/trunk/subversion/libsvn_fs_fs/fs_fs.c
> >> >URL:
> >> >
> http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_fs_fs/fs_fs.c?rev=1604421&r1=1604420&r2=1604421&view=diff
> >>
> >> >
> >==============================================================================
> >> >--- subversion/trunk/subversion/libsvn_fs_fs/fs_fs.c (original)
> >> >+++ subversion/trunk/subversion/libsvn_fs_fs/fs_fs.c Sat Jun 21
> 15:15:30
> >> > 2014
> >> >@@ -1449,15 +1449,35 @@ write_revision_zero(svn_fs_t *fs)
> >> >+ SVN_ERR(svn_io_file_create_binary(path_revision_zero,
> >> >+ "PLAIN\nEND\nENDREP\n"
> >> >+ "id: 0.0.r0/2\n"
> >> >+ "type: dir\n"
> >> >+ "count: 0\n"
> >> >+ "text: 0 3 4 4 "
> >> >+ "2d2977d1c96f487abe4a1e202dd03b4e\n"
> >> >+ "cpath: /\n"
> >> >+ "\n\n"
> >> >+
> >> >+ /* L2P index */
> >> >+ "\0\x80\x40" /* rev 0, 8k entries per page
> */
> >> >+ "\1\1\1" /* 1 rev, 1 page, 1 page in
> 1st
> >> > rev */
> >> >+ "\6\4" /* page size: bytes, count */
> >> >+ "\0\xd6\1\xb1\1\x21" /* phys offsets + 1 */
> >> >+
> >> >+ /* P2L index */
> >> >+ "\0\x6b" /* start rev, rev file size */
> >> >+ "\x80\x80\4\1\x1D" /* 64k pages, 1 page using 29
> >> > bytes */
> >> >+ "\0" /* offset entry 0 page 1 */
> >> >+ /* len, item & type, rev,
> >> > checksum */
> >> >+ "\x11\x34\0\xf5\xd6\x8c\x81\x06"
> >> >+ "\x59\x09\0\xc8\xfc\xf6\x81\x04"
> >> >+ "\1\x0d\0\x9d\x9e\xa9\x94\x0f"
> >> >+ "\x95\xff\3\x1b\0\0" /* last entry fills up 64k
> page
> >> > */
> >> >+
> >> >+ /* Footer */
> >> >+ "107 121\7",
> >> >+ 107 + 14 + 38 + 7 + 1, fs->pool));
> >> This constant makes code unreadable, unmaintainable and very error
> prone.
> >
> >
> > How?
> >
> > To make it more obvious that I intend to follow
> > the svn_io_file_create_binary interface, I added
> > some commentary explaining where the numbers
> > come from. But even just placing the sum (without
> > its elements) in there would be fine already.
> >
> > Changing the rev 0 template has never been a fun
> > activity and wont become one in the foreseeable
> > future.
> >
> I believe that the committer should be responsible forcommitting
> readable and easy to maintain code, not the reviewer. So please fix or
> revert.
>
Sorry, I should have referenced r1605444 in my post.
> >> > Modified: subversion/trunk/subversion/libsvn_fs_fs/rev_file.c
> >> > URL:
> >> >
> http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_fs_fs/rev_file.c?rev=1604421&r1=1604420&r2=1604421&view=diff
> >> >
> >> >
> ==============================================================================
> >> > --- subversion/trunk/subversion/libsvn_fs_fs/rev_file.c (original)
> >> > +++ subversion/trunk/subversion/libsvn_fs_fs/rev_file.c Sat Jun 21
> >> > 15:15:30 2014
> >> > @@ -23,6 +23,7 @@
> >> > #include "rev_file.h"
> >> > #include "fs_fs.h"
> >> > #include "index.h"
> >> > +#include "low_level.h"
> >> > #include "util.h"
> >> >
> >> > #include "../libsvn_fs/fs-loader.h"
> >> > @@ -46,6 +47,10 @@ init_revision_file(svn_fs_fs__revision_f
> >> > file->stream = NULL;
> >> > file->p2l_stream = NULL;
> >> > file->l2p_stream = NULL;
> >> > + file->block_size = ffd->block_size;
> >> > + file->l2p_offset = -1;
> >> > + file->p2l_offset = -1;
> >> > + file->footer_offset = -1;
> >> > file->pool = pool;
> >> > }
> >> >
> >> > @@ -127,14 +132,40 @@ svn_fs_fs__open_pack_or_rev_file(svn_fs_
> >> > }
> >> >
> >> > svn_error_t *
> >> > -svn_fs_fs__reopen_revision_file(svn_fs_fs__revision_file_t *file,
> >> > - svn_fs_t *fs,
> >> > - svn_revnum_t rev)
> >> > +svn_fs_fs__auto_read_footer(svn_fs_fs__revision_file_t *file)
> >> > {
> >> > - if (file->file)
> >> > - svn_fs_fs__close_revision_file(file);
> >> > + if (file->l2p_offset == -1)
> >> > + {
> >> > + apr_off_t filesize = 0;
> >> > + unsigned char footer_length;
> >> > + svn_stringbuf_t *footer;
> >> > +
> >> > + /* Determine file size. */
> >> > + SVN_ERR(svn_io_file_seek(file->file, APR_END, &filesize,
> >> > file->pool));
> >> > +
> >> > + /* Read last byte (containing the length of the footer). */
> >> > + SVN_ERR(svn_io_file_aligned_seek(file->file, file->block_size,
> >> > NULL,
> >> > + filesize - 1, file->pool));
> >> > + SVN_ERR(svn_io_file_read_full2(file->file, &footer_length,
> >> > + sizeof(footer_length), NULL,
> NULL,
> >> > + file->pool));
> >> > +
> >> > + /* Read footer. */
> >> > + footer = svn_stringbuf_create_ensure(footer_length,
> file->pool);
> >> > + SVN_ERR(svn_io_file_aligned_seek(file->file, file->block_size,
> >> > NULL,
> >> > + filesize - 1 - footer_length,
> >> > + file->pool));
> >> > + SVN_ERR(svn_io_file_read_full2(file->file, footer->data,
> >> > footer_length,
> >> > + &footer->len, NULL,
> file->pool));
> >> You're passing pointer to possible 32-bit value to function accepting
> >> pointer to 64-bit value. This will lead unpredictable results.
> >
> >
> > I assume you are referring to the &footer->len?
> > In that case, I think I'm passing an apr_size_t*
> > to an interface expecting an apr_size_t*.
> > What am I missing?
> >
> You're right. I confused svn_io_file_read_full2() with
> svn_io_file_seek(). The code above doesn't have problem I mentioned.
>
ack.
-- Stefan^2.
Received on 2014-06-25 17:55:01 CEST