Enable font caching

Update from ConTeXt, changes to save fonts under
TEXMFVAR/luatex-cache/latex/fonts.

1 files changed, 53 insertions, 0 deletions

diff --git a/otfl-luat-dum.lua b/otfl-luat-dum.lua
index 832f80d..6e2e1c6 100644
--- a/otfl-luat-dum.lua
+++ b/otfl-luat-dum.lua
@@ -73,3 +73,56 @@ function resolvers.findbinfile(name,kind)
     end
     return resolvers.find_file(name,(kind and remapper[kind]) or kind)
 end
+
+-- Caches ... I will make a real stupid version some day when I'm in the
+-- mood. After all, the generic code does not need the more advanced
+-- ConTeXt features. Cached data is not shared between ConTeXt and other
+-- usage as I don't want any dependency at all. Also, ConTeXt might have
+-- different needs and tricks added.
+
+caches = { }
+
+--~ containers.usecache = true
+
+function caches.setpath(category,subcategory)
+--  local root = kpse.var_value("TEXMFCACHE") or ""
+--  if root == "" then
+--      root = kpse.var_value("VARTEXMF") or ""
+--  end
+    local var  = kpse.var_value("TEXMFVAR")
+    local root = var and (var .. "/luatex-cache/latex") or ""
+    if root ~= "" then
+        root = file.join(root,category)
+        lfs.mkdir(root)
+        root = file.join(root,subcategory)
+        lfs.mkdir(root)
+        return lfs.isdir(root) and root
+    end
+end
+
+local function makefullname(path,name)
+    if path and path ~= "" then
+        name = "temp-" and name -- clash prevention
+        return file.addsuffix(file.join(path,name),"lua")
+    end
+end
+
+function caches.iswritable(path,name)
+    local fullname = makefullname(path,name)
+    return fullname and file.iswritable(fullname)
+end
+
+function caches.loaddata(path,name)
+    local fullname = makefullname(path,name)
+    if fullname then
+        local data = loadfile(fullname)
+        return data and data()
+    end
+end
+
+function caches.savedata(path,name,data)
+    local fullname = makefullname(path,name)
+    if fullname then
+        table.tofile(fullname,data,'return',false,true,false)
+    end
+end