[svn.haxx.se] · SVN Dev · SVN Users · SVN Org · TSVN Dev · TSVN Users · Subclipse Dev · Subclipse Users · this month's index

Re: svn commit: r33688 - branches/fsfs-pack/subversion/libsvn_fs_fs

From: David Glasser <glasser_at_davidglasser.net>
Date: Mon, 20 Oct 2008 17:01:18 -0700

Why not write to a temporary file and rename in place like we usually
do (which also gets around the issue from the other revision of
dealing with "incomplete pack files")?

--dave

On Thu, Oct 16, 2008 at 2:41 AM, <hwright_at_tigris.org> wrote:
> Author: hwright
> Date: Thu Oct 16 02:41:58 2008
> New Revision: 33688
>
> Log:
> On the fsfs-pack branch:
> Create a pack file from the full shards on disk. Note that once the shards are
> created, we don't have any way of reading them yet, so this will leave
> repositories in an unusable state.
>
> * subversion/libsvn_fs_fs/fs_fs.c
> (PACK_MANIFEST_ENTRY_LEN): New.
> (packer_baton, packer_func): New.
> (pack_shard): Build the pack file and the manifest, then glue them together
> and remove the old shard.
>
> Modified:
> branches/fsfs-pack/subversion/libsvn_fs_fs/fs_fs.c
>
> Modified: branches/fsfs-pack/subversion/libsvn_fs_fs/fs_fs.c
> URL: http://svn.collab.net/viewvc/svn/branches/fsfs-pack/subversion/libsvn_fs_fs/fs_fs.c?pathrev=33688&r1=33687&r2=33688
> ==============================================================================
> --- branches/fsfs-pack/subversion/libsvn_fs_fs/fs_fs.c Thu Oct 16 02:18:49 2008 (r33687)
> +++ branches/fsfs-pack/subversion/libsvn_fs_fs/fs_fs.c Thu Oct 16 02:41:58 2008 (r33688)
> @@ -102,6 +102,10 @@
> #define REP_PLAIN "PLAIN"
> #define REP_DELTA "DELTA"
>
> +/* The size of an entry in the pack file manifest, not including terminating
> + characters. */
> +#define PACK_MANIFEST_ENTRY_LEN 19
> +
> /* Notes:
>
> To avoid opening and closing the rev-files all the time, it would
> @@ -6371,6 +6375,50 @@ svn_fs_fs__begin_txn(svn_fs_txn_t **txn_
>
>
> /****** Packing FSFS shards *********/
> +struct packer_baton
> +{
> + apr_off_t next_offset;
> + svn_stream_t *pack_stream;
> + svn_stream_t *manifest_stream;
> +};
> +
> +/* Walker function used by pack_shard().
> + This implements svn_io_walk_func_t */
> +svn_error_t *
> +packer_func(void *baton,
> + const char *path,
> + const apr_finfo_t *finfo,
> + apr_pool_t *pool)
> +{
> + struct packer_baton *pb = baton;
> + int shard = atoi(finfo->name);
> + const char *offset_str;
> + svn_stream_t *rev_stream;
> + apr_off_t offset;
> + apr_size_t nbytes;
> +
> + /* Ignore any directories we find. */
> + if (finfo->filetype == APR_DIR)
> + return SVN_NO_ERROR;
> +
> + /* Update the manifest. */
> + svn_stream_printf(pb->manifest_stream, pool,
> + "%-" APR_STRINGIFY(PACK_MANIFEST_ENTRY_LEN) "ld\n",
> + pb->next_offset);
> + pb->next_offset += finfo->size;
> +
> + /* Copy all the bits from the rev file to the end of the pack file. */
> + SVN_ERR(svn_stream_open_readonly(&rev_stream, path, pool, pool));
> + SVN_ERR(svn_stream_copy2(rev_stream, pb->pack_stream, NULL, NULL, pool));
> + svn_stream_close(rev_stream);
> +
> + return SVN_NO_ERROR;
> +}
> +
> +/* Pack a single shard SHARD in REVS_DIR, using POOL for allocations.
> +
> + If for some reason we detect a partial packing already performed, we
> + remove the pack file and start again. */
> svn_error_t *
> pack_shard(const char *revs_dir,
> apr_int64_t shard,
> @@ -6378,12 +6426,17 @@ pack_shard(const char *revs_dir,
> {
> svn_node_kind_t pack_kind;
> svn_node_kind_t shard_kind;
> + apr_file_t *pack_file;
> + apr_file_t *manifest_file;
> + const char *manifest_path;
> + const char *tmp_file_path;
> const char *pack_file_path = svn_path_join(revs_dir,
> apr_psprintf(pool, "%ld.pack",
> shard), pool);
> const char *shard_path = svn_path_join(revs_dir,
> apr_psprintf(pool, "%ld", shard),
> pool);
> + struct packer_baton pb;
>
> /* Do some consistency checking. */
> SVN_ERR(svn_io_check_path(pack_file_path, &pack_kind, pool));
> @@ -6391,13 +6444,39 @@ pack_shard(const char *revs_dir,
> if (pack_kind == svn_node_file)
> {
> if (shard_kind == svn_node_dir)
> + /* If the packed shard and the "normal" shard exist, assume the pack
> + wasn't cleanly completed, and just delete the packed shard. */
> SVN_ERR(svn_io_remove_file(pack_file_path, pool));
> else
> /* We have already packed this shard, so just leave. */
> return SVN_NO_ERROR;
> }
>
> - return SVN_NO_ERROR;
> + /* Create the new pack file. */
> + SVN_ERR(svn_io_file_open(&pack_file, pack_file_path,
> + APR_WRITE | APR_CREATE | APR_BUFFERED,
> + APR_OS_DEFAULT, pool));
> + SVN_ERR(svn_io_open_unique_file2(&manifest_file, &tmp_file_path,
> + manifest_path, ".manifest",
> + svn_io_file_del_on_pool_cleanup, pool));
> + pb.next_offset = 0;
> + pb.pack_stream = svn_stream_from_aprfile2(pack_file, FALSE, pool);
> + pb.manifest_stream = svn_stream_from_aprfile2(manifest_file, FALSE, pool);
> + SVN_ERR(svn_io_dir_walk(shard_path,
> + APR_FINFO_TYPE | APR_FINFO_NAME | APR_FINFO_SIZE,
> + packer_func, &pb, pool));
> + SVN_ERR(svn_stream_close(pb.manifest_stream));
> +
> + /* Copy the manifest to the end of the pack file. */
> + SVN_ERR(svn_stream_open_readonly(&pb.manifest_stream, tmp_file_path, pool,
> + pool));
> + SVN_ERR(svn_stream_copy2(pb.manifest_stream, pb.pack_stream, NULL, NULL,
> + pool));
> + SVN_ERR(svn_stream_close(pb.manifest_stream));
> + SVN_ERR(svn_stream_close(pb.pack_stream));
> +
> + /* Finally, remove the existing shard directory. */
> + return svn_io_remove_dir2(shard_path, TRUE, NULL, NULL, pool);
> }
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: svn-unsubscribe_at_subversion.tigris.org
> For additional commands, e-mail: svn-help_at_subversion.tigris.org
>
>

-- 
David Glasser | glasser@davidglasser.net | http://www.davidglasser.net/
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe_at_subversion.tigris.org
For additional commands, e-mail: dev-help_at_subversion.tigris.org
Received on 2008-10-21 02:01:53 CEST

This is an archived mail posted to the Subversion Dev mailing list.