Re: svn commit: r31820 - trunk/subversion/libsvn_fs_base

Karl (and others with BDB backend knowledge): this fix seems too easy to be
true. Can you sanity check it, please?

cmpilato_at_tigris.org wrote:
> Author: cmpilato
> Date: Thu Jun 19 14:26:29 2008
> New Revision: 31820
>
> Log:
> Avoid a bunch of unnecessary database queries during the post-commit
> deltification phase in Berkeley DB repositories.
>
> deltify_mutable(), when recursing, iterates over directory entries,
> calling itself. The first thing it does is check the provided path's
> node kind and node-revision-ID. But both of those pieces of
> information are already available in the entries over which the caller
> is iterating! So, this change just lets the caller pass the
> information it already has on hand into deltify_mutable(). This has
> significant impact in some situations. On a test repository
> containing a directory of almost 20,000 files, commit which removed 10
> of those files at a time went from spending 13 minutes in delification
> to just a few seconds.
>
> * subversion/libsvn_fs_base/tree.c
> (deltify_mutable): Add 'node_id' and 'kind' parameters. Avoid
> querying for those bits of information when provided by the caller.
> And *do* provide that information in recursive calls.
> (svn_fs_base__deltify): Update call to deltify_mutable().
>
> Modified:
> trunk/subversion/libsvn_fs_base/tree.c
>
> Modified: trunk/subversion/libsvn_fs_base/tree.c
> URL: http://svn.collab.net/viewvc/svn/trunk/subversion/libsvn_fs_base/tree.c?pathrev=31820&r1=31819&r2=31820
> ==============================================================================
> --- trunk/subversion/libsvn_fs_base/tree.c Thu Jun 19 14:04:43 2008 (r31819)
> +++ trunk/subversion/libsvn_fs_base/tree.c Thu Jun 19 14:26:29 2008 (r31820)
> @@ -1582,22 +1582,30 @@ txn_body_pred_id(void *baton, trail_t *t
> }
>
>
> -/* Deltify ID's predecessor iff ID is mutable under TXN_ID in FS. If
> - ID is a mutable directory, recurse. Do this as part of TRAIL. */
> +/* Deltify PATH in ROOT's predecessor iff PATH is mutable under TXN_ID
> + in FS. If PATH is a mutable directory, recurse.
> +
> + NODE_ID is the node revision ID for PATH in ROOT, or NULL if that
> + value isn't known. KIND is the node kind for PATH in ROOT, or
> + svn_node_unknown is the kind isn't known.
> +
> + Use POOL for necessary allocations. */
> static svn_error_t *
> deltify_mutable(svn_fs_t *fs,
> svn_fs_root_t *root,
> const char *path,
> + const svn_fs_id_t *node_id,
> + svn_node_kind_t kind,
> const char *txn_id,
> apr_pool_t *pool)
> {
> - const svn_fs_id_t *id;
> + const svn_fs_id_t *id = node_id;
> apr_hash_t *entries = NULL;
> - svn_node_kind_t kind;
> struct txn_deltify_args td_args;
>
> - /* Get the ID for PATH under ROOT. */
> - SVN_ERR(base_node_id(&id, root, path, pool));
> + /* Get the ID for PATH under ROOT if it wasn't provided. */
> + if (! node_id)
> + SVN_ERR(base_node_id(&id, root, path, pool));
>
> /* Check for mutability. Not mutable? Go no further. This is safe
> to do because for items in the tree to be mutable, their parent
> @@ -1607,7 +1615,8 @@ deltify_mutable(svn_fs_t *fs,
> return SVN_NO_ERROR;
>
> /* Is this a directory? */
> - SVN_ERR(base_check_path(&kind, root, path, pool));
> + if (kind == svn_node_unknown)
> + SVN_ERR(base_check_path(&kind, root, path, pool));
>
> /* If this is a directory, read its entries. */
> if (kind == svn_node_dir)
> @@ -1624,11 +1633,14 @@ deltify_mutable(svn_fs_t *fs,
> /* KEY will be the entry name, VAL the dirent (about
> which we really don't care) */
> const void *key;
> + void *val;
> + svn_fs_dirent_t *entry;
> svn_pool_clear(subpool);
> - apr_hash_this(hi, &key, NULL, NULL);
> + apr_hash_this(hi, &key, NULL, &val);
> + entry = val;
> SVN_ERR(deltify_mutable(fs, root,
> svn_path_join(path, key, subpool),
> - txn_id, subpool));
> + entry->id, entry->kind, txn_id, subpool));
> }
>
> svn_pool_destroy(subpool);
> @@ -2686,7 +2698,7 @@ svn_fs_base__deltify(svn_fs_t *fs,
> args.revision = revision;
> SVN_ERR(svn_fs_base__retry_txn(fs, txn_body_rev_get_txn_id, &args, pool));
>
> - return deltify_mutable(fs, root, "/", txn_id, pool);
> + return deltify_mutable(fs, root, "/", NULL, svn_node_unknown, txn_id, pool);
> }
>
>
>
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-- 
C. Michael Pilato <cmpilato_at_collab.net>
CollabNet   <>   www.collab.net   <>   Distributed Development On Demand