diff --git a/sql/swh-func.sql b/sql/swh-func.sql
index 9ae558e6..8b483dc9 100644
--- a/sql/swh-func.sql
+++ b/sql/swh-func.sql
@@ -1,211 +1,255 @@
 
 -- create a temporary table called tmp_TBLNAME, mimicking existing table
 -- TBLNAME
 --
 -- Args:
 --     tblname: name of the table to mimick
 create or replace function swh_mktemp(tblname regclass)
     returns void
     language plpgsql
 as $$
 begin
     execute format('
 	create temporary table tmp_%I
 	    (like %I including defaults)
 	    on commit drop
 	', tblname, tblname);
     return;
 end
 $$;
 
 -- create a temporary table for directory entries called tmp_TBLNAME,
 -- mimicking existing table TBLNAME with an extra dir_id (sha1_git)
 -- column, and dropping the id column.
 --
 -- This is used to create the tmp_directory_entry_<foo> tables.
 --
 -- Args:
 --     tblname: name of the table to mimick
 create or replace function swh_mktemp_dir_entry(tblname regclass)
     returns void
     language plpgsql
 as $$
 begin
     execute format('
 	create temporary table tmp_%I
 	    (like %I including defaults, dir_id sha1_git)
 	    on commit drop;
         alter table tmp_%I drop column id;
 	', tblname, tblname, tblname, tblname);
     return;
 end
 $$;
 
 
 -- a content signature is a set of cryptographic checksums that we use to
 -- uniquely identify content, for the purpose of verifying if we already have
 -- some content or not during content injection
 create type content_signature as (
     sha1      sha1,
     sha1_git  sha1_git,
     sha256    sha256
 );
 
 
 -- check which entries of tmp_content are missing from content
 --
 -- operates in bulk: 0. swh_mktemp(content), 1. COPY to tmp_content,
 -- 2. call this function
 create or replace function swh_content_missing()
     returns setof content_signature
     language plpgsql
 as $$
 begin
     return query
 	select sha1, sha1_git, sha256 from tmp_content
 	except
 	select sha1, sha1_git, sha256 from content;
     return;
 end
 $$;
 
 
 -- add tmp_content entries to content, skipping duplicates
 --
 -- operates in bulk: 0. swh_mktemp(content), 1. COPY to tmp_content,
 -- 2. call this function
 create or replace function swh_content_add()
     returns void
     language plpgsql
 as $$
 declare
     rows bigint;
 begin
     insert into content (sha1, sha1_git, sha256, length, status)
 	select distinct sha1, sha1_git, sha256, length, status
 	from tmp_content
 	where (sha1, sha1_git, sha256) in
 	    (select * from swh_content_missing());
 	    -- TODO XXX use postgres 9.5 "UPSERT" support here, when available.
 	    -- Specifically, using "INSERT .. ON CONFLICT IGNORE" we can avoid
 	    -- the extra swh_content_missing() query here.
     return;
 end
 $$;
 
 
 -- check which entries of tmp_directory are missing from directory
 --
 -- operates in bulk: 0. swh_mktemp(directory), 1. COPY to tmp_directory,
 -- 2. call this function
 create or replace function swh_directory_missing()
     returns setof directory
     language plpgsql
 as $$
 begin
     return query
 	select id from tmp_directory
 	except
 	select id from directory;
     return;
 end
 $$;
 
 -- Add tmp_directory_entry_dir entries to directory_entry_dir and
 -- directory_list_dir, skipping duplicates in directory_entry_dir.
 --
 -- operates in bulk: 0. swh_mktemp_dir_entry('directory_entry_dir'), 1 COPY to
 -- tmp_directory_entry_dir, 2. call this function
 create or replace function swh_directory_entry_dir_add()
     returns void
     language plpgsql
 as $$
 begin
     insert into directory_entry_dir (target, name, perms, atime, mtime, ctime)
     select t.target, t.name, t.perms, t.atime, t.mtime, t.ctime
     from tmp_directory_entry_dir t
     where not exists (
     select 1
     from directory_entry_dir i
     where t.target = i.target and t.name = i.name and t.perms = i.perms and
        t.atime is not distinct from i.atime and
        t.mtime is not distinct from i.mtime and
        t.ctime is not distinct from i.ctime);
 
     insert into directory_list_dir (entry_id, dir_id)
     select i.id, t.dir_id
     from tmp_directory_entry_dir t
     inner join directory_entry_dir i
     on t.target = i.target and t.name = i.name and t.perms = i.perms and
        t.atime is not distinct from i.atime and
        t.mtime is not distinct from i.mtime and
        t.ctime is not distinct from i.ctime;
     return;
 end
 $$;
 
 -- Add tmp_directory_entry_file entries to directory_entry_file and
 -- directory_list_file, skipping duplicates in directory_entry_file.
 --
 -- operates in bulk: 0. swh_mktemp_dir_entry('directory_entry_file'), 1 COPY to
 -- tmp_directory_entry_file, 2. call this function
 create or replace function swh_directory_entry_file_add()
     returns void
     language plpgsql
 as $$
 begin
     insert into directory_entry_file (target, name, perms, atime, mtime, ctime)
     select t.target, t.name, t.perms, t.atime, t.mtime, t.ctime
     from tmp_directory_entry_file t
     where not exists (
     select 1
     from directory_entry_file i
     where t.target = i.target and t.name = i.name and t.perms = i.perms and
        t.atime is not distinct from i.atime and
        t.mtime is not distinct from i.mtime and
        t.ctime is not distinct from i.ctime);
 
     insert into directory_list_file (entry_id, dir_id)
     select i.id, t.dir_id
     from tmp_directory_entry_file t
     inner join directory_entry_file i
     on t.target = i.target and t.name = i.name and t.perms = i.perms and
        t.atime is not distinct from i.atime and
        t.mtime is not distinct from i.mtime and
        t.ctime is not distinct from i.ctime;
     return;
 end
 $$;
 
 -- Add tmp_directory_entry_rev entries to directory_entry_rev and
 -- directory_list_rev, skipping duplicates in directory_entry_rev.
 --
 -- operates in bulk: 0. swh_mktemp_dir_entry('directory_entry_rev'), 1 COPY to
 -- tmp_directory_entry_rev, 2. call this function
 create or replace function swh_directory_entry_rev_add()
     returns void
     language plpgsql
 as $$
 begin
     insert into directory_entry_rev (target, name, perms, atime, mtime, ctime)
     select t.target, t.name, t.perms, t.atime, t.mtime, t.ctime
     from tmp_directory_entry_rev t
     where not exists (
     select 1
     from directory_entry_rev i
     where t.target = i.target and t.name = i.name and t.perms = i.perms and
        t.atime is not distinct from i.atime and
        t.mtime is not distinct from i.mtime and
        t.ctime is not distinct from i.ctime);
 
     insert into directory_list_rev (entry_id, dir_id)
     select i.id, t.dir_id
     from tmp_directory_entry_rev t
     inner join directory_entry_rev i
     on t.target = i.target and t.name = i.name and t.perms = i.perms and
        t.atime is not distinct from i.atime and
        t.mtime is not distinct from i.mtime and
        t.ctime is not distinct from i.ctime;
     return;
 end
 $$;
+
+-- a directory listing entry with all the metadata
+--
+-- can be used to list a directory, and retrieve all the data in one go.
+create type directory_entry as
+(
+  dir_id  sha1_git,     -- id of the parent directory
+  type    text,         -- type of entry (one of 'dir', 'file', 'rev')
+  target  sha1_git,     -- id of target
+  name    unix_path,    -- path name, relative to containing dir
+  perms   file_perms,   -- unix-like permissions
+  atime   timestamptz,  -- time of last access
+  mtime   timestamptz,  -- time of last modification
+  ctime   timestamptz   -- time of last status change
+);
+
+-- List a single level of directory walked_dir_id
+create or replace function swh_directory_walk_one(walked_dir_id sha1_git)
+    returns setof directory_entry
+    language plpgsql
+as $$
+begin
+    return query (
+        select dir_id, 'dir' as type, target, name, perms, atime, mtime, ctime
+	from directory_list_dir l
+	left join directory_entry_dir d
+	on l.entry_id = d.id
+	where l.dir_id = walked_dir_id
+    union
+        select dir_id, 'file' as type, target, name, perms, atime, mtime, ctime
+	from directory_list_file l
+	left join directory_entry_file d
+	on l.entry_id = d.id
+	where l.dir_id = walked_dir_id
+    union
+        select dir_id, 'rev' as type, target, name, perms, atime, mtime, ctime
+	from directory_list_rev l
+	left join directory_entry_rev d
+	on l.entry_id = d.id
+	where l.dir_id = walked_dir_id
+    ) order by name;
+    return;
+end
+$$;