path: root/tex/context/base/luat-tmp.lua

if not modules then modules = { } end modules ['luat-tmp'] = {
    version   = 1.001,
    comment   = "companion to luat-lib.tex",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files"
}

--[[ldx--
<p>This module deals with caching data. It sets up the paths and
implements loaders and savers for tables. Best is to set the
following variable. When not set, the usual paths will be
checked. Personally I prefer the (users) temporary path.</p>

</code>
TEXMFCACHE=$TMP;$TEMP;$TMPDIR;$TEMPDIR;$HOME;$TEXMFVAR;$VARTEXMF;.
</code>

<p>Currently we do no locking when we write files. This is no real
problem because most caching involves fonts and the chance of them
being written at the same time is small. We also need to extend
luatools with a recache feature.</p>
--ldx]]--

caches = caches or { }
dir    = dir    or { }
texmf  = texmf  or { }

caches.path   = caches.path or nil
caches.base   = caches.base or "luatex-cache"
caches.more   = caches.more or "context"
caches.direct = false -- true is faster but may need huge amounts of memory
caches.trace  = false
caches.tree   = false
caches.temp   = caches.temp or os.getenv("TEXMFCACHE") or os.getenv("HOME") or os.getenv("HOMEPATH") or os.getenv("VARTEXMF") or os.getenv("TEXMFVAR") or os.getenv("TMP") or os.getenv("TEMP") or os.getenv("TMPDIR") or nil
caches.paths  = caches.paths or { caches.temp }
caches.force  = false

input.usecache = not toboolean(os.getenv("TEXMFSHARECACHE") or "false",true) -- true

if caches.temp and caches.temp ~= "" and lfs.attributes(caches.temp,"mode") ~= "directory" then
    if caches.force or io.ask(string.format("Should I create the cache path %s?",caches.temp), "no", { "yes", "no" }) == "yes" then
        dir.mkdirs(caches.temp)
    end
end
if not caches.temp or caches.temp == "" then
    print("\nfatal error: there is no valid cache path defined\n")
    os.exit()
elseif lfs.attributes(caches.temp,"mode") ~= "directory" then
    print(string.format("\nfatal error: cache path %s is not a directory\n",caches.temp))
    os.exit()
end

function caches.configpath(instance)
    return table.concat(instance.cnffiles,";")
--~     return input.expand_var(instance,"TEXMFCNF")
end

function caches.treehash(instance)
    local tree = caches.configpath(instance)
    if not tree or tree == "" then
        return false
    else
        return md5.hex(tree)
    end
end

function caches.setpath(instance,...)
    if not caches.path then
        if lfs and instance then
            for _,v in pairs(caches.paths) do
                for _,vv in pairs(input.expanded_path_list(instance,v)) do
                    if lfs.isdir(vv) then
                        caches.path = vv
                        break
                    end
                end
                if caches.path then break end
            end
        end
        if not caches.path then
            caches.path = caches.temp
        end
        caches.path = input.clean_path(caches.path) -- to be sure
        if lfs then
            caches.tree = caches.tree or caches.treehash(instance)
            if caches.tree then
                caches.path = dir.mkdirs(caches.path,caches.base,caches.more,caches.tree)
            else
                caches.path = dir.mkdirs(caches.path,caches.base,caches.more)
            end
        end
    end
    if not caches.path then
        caches.path = '.'
    end
    caches.path = input.clean_path(caches.path)
    if lfs and not table.is_empty({...}) then
        local pth = dir.mkdirs(caches.path,...)
        return pth
    end
    return caches.path
end

function caches.setluanames(path,name)
    return path .. "/" .. name .. ".tma", path .. "/" .. name .. ".tmc"
end

function caches.loaddata(path,name)
    local tmaname, tmcname = caches.setluanames(path,name)
    local loader = loadfile(tmcname) or loadfile(tmaname)
    if loader then
        return loader()
    else
        return false
    end
end

function caches.is_writable(filepath,filename)
    local tmaname, tmcname = caches.setluanames(filepath,filename)
    return file.is_writable(tmaname)
end

function caches.savedata(filepath,filename,data,raw) -- raw needed for file cache
    local tmaname, tmcname = caches.setluanames(filepath,filename)
    local reduce, simplify = true, true
    if raw then
        reduce, simplify = false, false
    end
    if caches.direct then
        file.savedata(tmaname, table.serialize(data,'return',true,true))
    else
        table.tofile (tmaname,                 data,'return',true,true) -- maybe not the last true
    end
    utils.lua.compile(tmaname, tmcname)
end

-- here we use the cache for format loading (texconfig.[formatname|jobname])

if tex and texconfig and texconfig.formatname and texconfig.formatname == "" then
    if not texconfig.luaname then texconfig.luaname = "cont-en.lua" end
    texconfig.formatname = caches.setpath(instance,"format") .. "/" .. texconfig.luaname:gsub("%.lu.$",".fmt")
end

--[[ldx--
<p>Once we found ourselves defining similar cache constructs
several times, containers were introduced. Containers are used
to collect tables in memory and reuse them when possible based
on (unique) hashes (to be provided by the calling function).</p>

<p>Caching to disk is disabled by default. Version numbers are
stored in the saved table which makes it possible to change the
table structures without bothering about the disk cache.</p>

<p>Examples of usage can be found in the font related code.</p>
--ldx]]--

containers       = { }
containers.trace = false

do -- local report

    local function report(container,tag,name)
        if caches.trace or containers.trace or container.trace then
            logs.report(string.format("%s cache",container.subcategory),string.format("%s: %s",tag,name or 'invalid'))
        end
    end

    function containers.define(category, subcategory, version, enabled)
        if category and subcategory then
            return {
                category = category,
                subcategory = subcategory,
                storage = { },
                enabled = enabled,
                version = version or 1.000,
                trace = false,
                path = caches.setpath(texmf.instance,category,subcategory),
            }
        else
            return nil
        end
    end

    function containers.is_usable(container, name)
        return container.enabled and caches.is_writable(container.path, name)
    end

    function containers.is_valid(container, name)
        if name and name ~= "" then
            local storage = container.storage[name]
            return storage and not table.is_empty(storage) and storage.cache_version == container.version
        else
            return false
        end
    end

    function containers.read(container,name)
        if container.enabled and not container.storage[name] then
            container.storage[name] = caches.loaddata(container.path,name)
            if containers.is_valid(container,name) then
                report(container,"loaded",name)
            else
                container.storage[name] = nil
            end
        end
        if container.storage[name] then
            report(container,"reusing",name)
        end
        return container.storage[name]
    end

    function containers.write(container, name, data)
        if data then
            data.cache_version = container.version
            if container.enabled then
                local unique, shared = data.unique, data.shared
                data.unique, data.shared = nil, nil
                caches.savedata(container.path, name, data)
                report(container,"saved",name)
                data.unique, data.shared = unique, shared
            end
            report(container,"stored",name)
            container.storage[name] = data
        end
        return data
    end

    function containers.content(container,name)
        return container.storage[name]
    end

end

-- since we want to use the cache instead of the tree, we will now
-- reimplement the saver.

function input.aux.save_data(instance, dataname, check)
    for cachename, files in pairs(instance[dataname]) do
        local name
        if input.usecache then
            name = file.join(caches.setpath(instance,"trees"),md5.hex(cachename))
        else
            name = file.join(cachename,dataname)
        end
        local luaname, lucname = name .. input.luasuffix, name .. input.lucsuffix
        input.report("preparing " .. dataname .. " in", luaname)
        for k, v in pairs(files) do
            if not check or check(v,k) then -- path, name
                if type(v) == "table" and #v == 1 then
                    files[k] = v[1]
                end
            else
                files[k] = nil -- false
            end
        end
        local data = {
            type    = dataname,
            root    = cachename,
            version = input.cacheversion,
            date    = os.date("%Y-%m-%d"),
            time    = os.date("%H:%M:%S"),
            content = files,
        }
        local f = io.open(luaname,'w')
        if f then
            input.report("saving " .. dataname .. " in", luaname)
        --  f:write(table.serialize(data,'return'))
            f:write(input.serialize(data))
            f:close()
            input.report("compiling " .. dataname .. " to", lucname)
            if not utils.lua.compile(luaname,lucname) then
                input.report("compiling failed for " .. dataname .. ", deleting file " .. lucname)
                os.remove(lucname)
            end
        else
            input.report("unable to save " .. dataname .. " in " .. name..input.luasuffix)
        end
    end
end

function input.serialize(files)
    -- This version is somewhat optimized for the kind of
    -- tables that we deal with, so it's much faster than
    -- the generic serializer. This makes sense because
    -- luatools and mtxtools are called frequently. Okay,
    -- we pay a small price for properly tabbed tables.
    local t = { }
    local concat = table.concat
    local sorted = table.sortedkeys
    local function dump(k,v,m)
        if type(v) == 'string' then
            return m .. "['" .. k .. "']='" .. v .. "',"
        elseif #v == 1 then
            return m .. "['" .. k .. "']='" .. v[1] .. "',"
        else
            return m .. "['" .. k .. "']={'" .. concat(v,"','").. "'},"
        end
    end
    t[#t+1] = "return {"
    if instance.sortdata then
        for _, k in pairs(sorted(files)) do
            local fk  = files[k]
            if type(fk) == 'table' then
                t[#t+1] = "\t['" .. k .. "']={"
                for _, kk in pairs(sorted(fk)) do
                    t[#t+1] = dump(kk,fk[kk],"\t\t")
                end
                t[#t+1] = "\t},"
            else
                t[#t+1] = dump(k,fk,"\t")
            end
        end
    else
        for k, v in pairs(files) do
            if type(v) == 'table' then
                t[#t+1] = "\t['" .. k .. "']={"
                for kk,vv in pairs(v) do
                    t[#t+1] = dump(kk,vv,"\t\t")
                end
                t[#t+1] = "\t},"
            else
                t[#t+1] = dump(k,v,"\t")
            end
        end
    end
    t[#t+1] = "}"
    return concat(t,"\n")
end

function input.aux.load_data(instance,pathname,dataname,filename)
    local luaname, lucname, pname, fname
    if input.usecache then
        pname, fname = caches.setpath(instance,"trees"), md5.hex(pathname)
        filename = file.join(pname,fname)
    else
        if not filename or (filename == "") then
            filename = dataname
        end
        pname, fname = pathname, filename
    end
    luaname = file.join(pname,fname) .. input.luasuffix
    lucname = file.join(pname,fname) .. input.lucsuffix
    local blob = loadfile(lucname)
    if not blob then
        blob = loadfile(luaname)
    end
    if blob then
        local data = blob()
        if data and data.content and data.type == dataname and data.version == input.cacheversion then
            input.report("loading",dataname,"for",pathname,"from",filename)
            instance[dataname][pathname] = data.content
        else
            input.report("skipping",dataname,"for",pathname,"from",filename)
            instance[dataname][pathname] = { }
            instance.loaderror = true
        end
    else
        input.report("skipping",dataname,"for",pathname,"from",filename)
    end
end

-- we will make a better format, maybe something xml or just text or lua

input.automounted = input.automounted or { }

function input.automount(instance,usecache)
    local mountpaths = input.simplified_list(input.expansion(instance,'TEXMFMOUNT'))
    if table.is_empty(mountpaths) and usecache then
        mountpaths = { caches.setpath(instance,"mount") }
    end
    if not table.is_empty(mountpaths) then
        input.starttiming(instance)
        for k, root in pairs(mountpaths) do
            local f = io.open(root.."/url.tmi")
            if f then
                for line in f:lines() do
                    if line then
                        if line:find("^[%%#%-]") then -- or %W
                            -- skip
                        elseif line:find("^zip://") then
                            input.report("mounting",line)
                            table.insert(input.automounted,line)
                            input.usezipfile(instance,line)
                        end
                    end
                end
                f:close()
            end
        end
        input.stoptiming(instance)
    end
end

-- store info in format

input.storage            = { }
input.storage.data       = { }
input.storage.min        = 0 -- 500
input.storage.max        = input.storage.min - 1
input.storage.trace      = false -- true
input.storage.done       = 0
input.storage.evaluators = { }
-- (evaluate,message,names)

function input.storage.register(...)
    input.storage.data[#input.storage.data+1] = { ... }
end

function input.storage.evaluate(name)
    input.storage.evaluators[#input.storage.evaluators+1] = name
end

function input.storage.finalize() -- we can prepend the string with "evaluate:"
    for _, t in ipairs(input.storage.evaluators) do
        for i, v in pairs(t) do
            if type(v) == "string" then
                t[i] = loadstring(v)()
            elseif type(v) == "table" then
                for _, vv in pairs(v) do
                    if type(vv) == "string" then
                        t[i] = loadstring(vv)()
                    end
                end
            end
        end
    end
end

function input.storage.dump()
    for name, data in ipairs(input.storage.data) do
        local evaluate, message, original, target = data[1], data[2], data[3] ,data[4]
        local name, initialize, finalize, code = nil, "", "", ""
        for str in target:gmatch("([^%.]+)") do
            if name then
                name = name .. "." .. str
            else
                name = str
            end
            initialize = string.format("%s %s = %s or {} ", initialize, name, name)
        end
        if evaluate then
            finalize = "input.storage.evaluate(" .. name .. ")"
        end
        input.storage.max = input.storage.max + 1
        if input.storage.trace then
            logs.report('storage',string.format('saving %s in slot %s',message,input.storage.max))
            code =
                initialize ..
                string.format("logs.report('storage','restoring %s from slot %s') ",message,input.storage.max) ..
                table.serialize(original,name) ..
                finalize
        else
            code = initialize .. table.serialize(original,name) .. finalize
        end
        lua.bytecode[input.storage.max] = loadstring(code)
    end
end

if lua.bytecode then -- from 0 upwards
    local i = input.storage.min
    while lua.bytecode[i] do
        lua.bytecode[i]()
        lua.bytecode[i] = nil
        i = i + 1
    end
    input.storage.done = i
end