aux: add helpers for accessing the index table/index file

2 files changed, 53 insertions, 2 deletions

diff --git a/src/luaotfload-auxiliary.lua b/src/luaotfload-auxiliary.lua
index 14c2ab5..89bf51b 100644
--- a/src/luaotfload-auxiliary.lua
+++ b/src/luaotfload-auxiliary.lua
@@ -20,6 +20,7 @@ local log                   = luaotfload.log
 local report                = log.report
 local fonthashes            = fonts.hashes
 local identifiers           = fonthashes.identifiers
+local fontnames             = fonts.names
 
 local fontid                = font.id
 local texsprint             = tex.sprint
@@ -590,8 +591,8 @@ aux.sprint_math_dimension = sprint_math_dimension
 ---                    extra database functions
 -----------------------------------------------------------------------
 
-local namesresolve      = fonts.names.resolve
-local namesscan_dir     = fonts.names.scan_dir
+local namesresolve      = fontnames.resolve
+local namesscan_dir     = fontnames.scan_dir
 
 --[====[-- TODO -> port this to new db model
 
@@ -663,6 +664,42 @@ end
 
 aux.resolve_fontlist = resolve_fontlist
 
+--- index access ------------------------------------------------------
+
+--- Based on a discussion on the Luatex mailing list:
+--- http://tug.org/pipermail/luatex/2014-June/004881.html
+
+--[[doc--
+
+  aux.read_font_index -- Read the names index from the canonical
+  location and return its contents. This does not affect the behavior
+  of Luaotfload: The returned table is independent of what the font
+  resolvers use internally. Access is raw: each call to the function
+  will result in the entire table being re-read from disk.
+
+--doc]]--
+
+local load_names        = fontnames.load
+local access_font_index = fontnames.access_font_index
+
+local read_font_index = function ()
+  return load_names (true) or { }
+end
+
+--[[doc--
+
+  aux.font_index -- Access Luaotfload’s internal database. If the
+  database hasn’t been loaded yet this will cause it to be loaded, with
+  all the possible side-effects like for instance creating the index
+  file if it doesn’t exist, reading all font files, &c.
+
+--doc]]--
+
+local font_index = function () return access_font_index () end
+
+aux.read_font_index = read_font_index
+aux.font_index      = font_index
+
 --- loaded fonts ------------------------------------------------------
 
 --- just a proof of concept
diff --git a/src/luaotfload-database.lua b/src/luaotfload-database.lua
index f216f79..e171c52 100644
--- a/src/luaotfload-database.lua
+++ b/src/luaotfload-database.lua
@@ -452,6 +452,7 @@ local load_lua_file = function (path)
 end
 
 --- define locals in scope
+local access_font_index
 local collect_families
 local crude_file_lookup
 local crude_file_lookup_verbose
@@ -532,6 +533,18 @@ load_names = function (dry_run)
     return data
 end
 
+--[[doc--
+
+    access_font_index -- Provide a reference of the index table. Will
+    cause the index to be loaded if not present.
+
+--doc]]--
+
+access_font_index = function ()
+    if not name_index then name_index = load_names () end
+    return name_index
+end
+
 getmetadata = function ()
     if not name_index then name_index = load_names() end
     return tablefastcopy (name_index.meta)
@@ -3457,6 +3470,7 @@ names.set_font_filter             = set_font_filter
 names.flush_lookup_cache          = flush_lookup_cache
 names.save_lookups                = save_lookups
 names.load                        = load_names
+names.access_font_index           = access_font_index
 names.data                        = function () return name_index end
 names.save                        = save_names
 names.update                      = update_names