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authorPhilipp Gesang <phg@phi-gamma.net>2015-06-21 00:21:33 +0200
committerPhilipp Gesang <phg@phi-gamma.net>2015-06-21 00:21:33 +0200
commit6f273e157c650d396cbad8e09e059b8b7c359818 (patch)
treefbf3a288f190c5f057a95eb796aee421ad5612a5 /src/luaotfload-init.lua
parent90f398e1c9d2896b2d30d0b66f9c8a88255511a8 (diff)
parente8a56b051a32ed4c468c9325048ded01002a841a (diff)
downloadluaotfload-6f273e157c650d396cbad8e09e059b8b7c359818.tar.gz
Merge pull request #276 from phi-gamma/master
fixes; current progress regarding initialization
Diffstat (limited to 'src/luaotfload-init.lua')
-rw-r--r--src/luaotfload-init.lua303
1 files changed, 289 insertions, 14 deletions
diff --git a/src/luaotfload-init.lua b/src/luaotfload-init.lua
index 4968877..feff4cc 100644
--- a/src/luaotfload-init.lua
+++ b/src/luaotfload-init.lua
@@ -30,30 +30,305 @@
--doc]]--
-config = config or { }
-local config = config
-config.luaotfload = config.luaotfload or { }
+local log --- filled in after loading the log module
+local logreport --- filled in after loading the log module
-config.lualibs = config.lualibs or { }
-config.lualibs.verbose = false
-config.lualibs.prefer_merged = true
-config.lualibs.load_extended = true
+--[[doc--
+
+ \subsection{Preparing the Font Loader}
+ We treat the fontloader as a black box so behavior is consistent
+ between formats.
+ We load the fontloader code directly in the same fashion as the
+ Plain format \identifier{luatex-fonts} that is part of Context.
+ How this is executed depends on the presence on the
+ \emphasis{merged font loader code}.
+ In \identifier{luaotfload} this is contained in the file
+ \fileent{luaotfload-merged.lua}.
+ If this file cannot be found, the original libraries from \CONTEXT
+ of which the merged code was composed are loaded instead.
+ Since these files are not shipped with Luaotfload, an installation
+ of Context is required.
+ (Since we pull the fontloader directly from the Context minimals,
+ the necessary Context version is likely to be more recent than that
+ of other TeX distributions like Texlive.)
+ The imported font loader will call \luafunction{callback.register}
+ once while reading \fileent{font-def.lua}.
+ This is unavoidable unless we modify the imported files, but
+ harmless if we make it call a dummy instead.
+ However, this problem might vanish if we decide to do the merging
+ ourselves, like the \identifier{lualibs} package does.
+ With this step we would obtain the freedom to load our own
+ overrides in the process right where they are needed, at the cost
+ of losing encapsulation.
+ The decision on how to progress is currently on indefinite hold.
-require "lualibs"
+--doc]]--
-if not lualibs then error("this module requires Luaotfload") end
-if not luaotfload then error("this module requires Luaotfload") end
-local load_luaotfload_module = luaotfload.loaders.luaotfload
-local load_fontloader_module = luaotfload.loaders.fontloader
+local init_pre = function ()
---[[doc--
+ local store = { }
+ config = config or { } --- global
+ config.luaotfload = config.luaotfload or { }
+ config.lualibs = config.lualibs or { }
+ config.lualibs.verbose = false
+ config.lualibs.prefer_merged = true
+ config.lualibs.load_extended = true
+
+ require "lualibs"
+
+ if not lualibs then error "this module requires Luaotfload" end
+ if not luaotfload then error "this module requires Luaotfload" end
+
+ --[[doc--
The logger needs to be in place prior to loading the fontloader due
to order of initialization being crucial for the logger functions
that are swapped.
+ --doc]]--
+
+ luaotfload.loaders.luaotfload "log"
+ log = luaotfload.log
+ logreport = log.report
+ log.set_loglevel (default_log_level)
+
+ logreport ("log", 4, "init", "Concealing callback.register().")
+ store.trapped_register = callback.register
+
+ callback.register = function (id)
+ logreport ("log", 4, "init",
+ "Dummy callback.register() invoked on %s.",
+ id)
+ end
+
+ --[[doc--
+
+ By default, the fontloader requires a number of \emphasis{private
+ attributes} for internal use.
+ These must be kept consistent with the attribute handling methods
+ as provided by \identifier{luatexbase}.
+ Our strategy is to override the function that allocates new
+ attributes before we initialize the font loader, making it a
+ wrapper around \luafunction{luatexbase.new_attribute}.\footnote{%
+ Many thanks, again, to Hans Hagen for making this part
+ configurable!
+ }
+ The attribute identifiers are prefixed “\fileent{luaotfload@}” to
+ avoid name clashes.
+
+ --doc]]--
+
+ local new_attribute = luatexbase.new_attribute
+ local the_attributes = luatexbase.attributes
+
+ attributes = attributes or { } --- this writes a global, sorry
+
+ attributes.private = function (name)
+ local attr = "luaotfload@" .. name --- used to be: “otfl@”
+ local number = the_attributes[attr]
+ if not number then number = new_attribute(attr) end
+ return number
+ end
+
+ return store
+end --- [init_pre]
+
+--[[doc--
+
+ These next lines replicate the behavior of
+ \fileent{luatex-fonts.lua}.
+
--doc]]--
-load_luaotfload_module "log"
+local push_namespaces = function ()
+ logreport ("log", 4, "init", "push namespace for font loader")
+ local normalglobal = { }
+ for k, v in next, _G do
+ normalglobal[k] = v
+ end
+ return normalglobal
+end
+
+local pop_namespaces = function (normalglobal,
+ isolate,
+ context_environment)
+ if normalglobal then
+ local _G = _G
+ local mode = "non-destructive"
+ if isolate then mode = "destructive" end
+ logreport ("log", 4, "init", "pop namespace from font loader -- " .. mode)
+ for k, v in next, _G do
+ if not normalglobal[k] then
+ context_environment[k] = v
+ if isolate then
+ _G[k] = nil
+ end
+ end
+ end
+ for k, v in next, normalglobal do
+ _G[k] = v
+ end
+ -- just to be sure:
+ setmetatable(context_environment, _G)
+ else
+ logreport ("both", 0, "init",
+ "irrecoverable error during pop_namespace: no globals to restore")
+ os.exit ()
+ end
+end
+
+local init_adapt = function ()
+
+ luaotfload.context_environment = { }
+ luaotfload.push_namespaces = push_namespaces
+ luaotfload.pop_namespaces = pop_namespaces
+
+ local our_environment = push_namespaces ()
+
+ --[[doc--
+
+ The font loader requires that the attribute with index zero be
+ zero. We happily oblige.
+ (Cf. \fileent{luatex-fonts-nod.lua}.)
+
+ --doc]]--
+
+ tex.attribute[0] = 0
+
+ return our_environment
+
+end --- [init_adapt]
+
+local init_main = function ()
+
+ local load_fontloader_module = luaotfload.loaders.fontloader
+
+ --[[doc--
+
+ Now that things are sorted out we can finally load the
+ fontloader.
+
+ For less current distibutions we ship the code from TL 2014 that
+ should be compatible with Luatex 0.76.
+
+ --doc]]--
+
+ load_fontloader_module (luaotfload.fontloader_package)
+
+ ---load_fontloader_module "font-odv.lua" --- <= Devanagari support from Context
+
+ if not fonts then
+ --- the loading sequence is known to change, so this might have to
+ --- be updated with future updates!
+ --- do not modify it though unless there is a change to the merged
+ --- package!
+ load_fontloader_module "l-lua"
+ load_fontloader_module "l-lpeg"
+ load_fontloader_module "l-function"
+ load_fontloader_module "l-string"
+ load_fontloader_module "l-table"
+ load_fontloader_module "l-io"
+ load_fontloader_module "l-file"
+ load_fontloader_module "l-boolean"
+ load_fontloader_module "l-math"
+ load_fontloader_module "util-str"
+ load_fontloader_module "luatex-basics-gen"
+ load_fontloader_module "data-con"
+ load_fontloader_module "luatex-basics-nod"
+ load_fontloader_module "font-ini"
+ load_fontloader_module "font-con"
+ load_fontloader_module "luatex-fonts-enc"
+ load_fontloader_module "font-cid"
+ load_fontloader_module "font-map"
+ load_fontloader_module "luatex-fonts-syn"
+ load_fontloader_module "luatex-fonts-tfm"
+ load_fontloader_module "font-oti"
+ load_fontloader_module "font-otf"
+ load_fontloader_module "font-otb"
+ load_fontloader_module "luatex-fonts-inj" --> since 2014-01-07, replaces node-inj.lua
+ load_fontloader_module "luatex-fonts-ota"
+ load_fontloader_module "luatex-fonts-otn" --> since 2014-01-07, replaces font-otn.lua
+ load_fontloader_module "font-otp" --> since 2013-04-23
+ load_fontloader_module "luatex-fonts-lua"
+ load_fontloader_module "font-def"
+ load_fontloader_module "luatex-fonts-def"
+ load_fontloader_module "luatex-fonts-ext"
+ load_fontloader_module "luatex-fonts-cbk"
+ end --- non-merge fallback scope
+
+end --- [init_main]
+
+local init_cleanup = function (store)
+ --- reinstate all the stuff we had to move out of the way to
+ --- accomodate the loader
+
+ --[[doc--
+
+ Here we adjust the globals created during font loader
+ initialization. If the second argument to
+ \luafunction{pop_namespaces()} is \verb|true| this will restore the
+ state of \luafunction{_G}, eliminating every global generated since
+ the last call to \luafunction{push_namespaces()}. At the moment we
+ see no reason to do this, and since the font loader is considered
+ an essential part of \identifier{luatex} as well as a very well
+ organized piece of code, we happily concede it the right to add to
+ \luafunction{_G} if needed.
+
+ --doc]]--
+
+ luaotfload.pop_namespaces (store.our_environment,
+ false,
+ luaotfload.context_environment)
+
+ --[[doc--
+
+ \subsection{Callbacks}
+ After the fontloader is ready we can restore the callback trap
+ from \identifier{luatexbase}.
+
+ --doc]]--
+
+ logreport ("log", 4, "init",
+ "Restoring original callback.register().")
+ callback.register = store.trapped_register
+end --- [init_cleanup]
+
+local init_post = function ()
+ --- hook for actions that need to take place after the fontloader is
+ --- installed
+
+ --[[doc--
+
+ we do our own callback handling with the means provided by
+ luatexbase.
+ note: \luafunction{pre_linebreak_filter} and
+ \luafunction{hpack_filter} are coupled in \context in the
+ concept of \emphasis{node processor}.
+
+ --doc]]--
+
+ luatexbase.add_to_callback("pre_linebreak_filter",
+ nodes.simple_font_handler,
+ "luaotfload.node_processor",
+ 1)
+ luatexbase.add_to_callback("hpack_filter",
+ nodes.simple_font_handler,
+ "luaotfload.node_processor",
+ 1)
+end --- [init_post]
+
+return {
+ init = function ()
+ local starttime = os.gettimeofday ()
+ local store = init_pre ()
+ store.our_environment = init_adapt ()
+ init_main ()
+ init_cleanup (store)
+ logreport ("both", 1, "init",
+ "fontloader loaded in %0.3f seconds",
+ os.gettimeofday() - starttime)
+ init_post ()
+ end
+}