2016-01-12 16:26:00

1 files changed, 141 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/data-met.lua b/tex/context/base/mkiv/data-met.lua
new file mode 100644
index 000000000..4e8a48f50
--- /dev/null
+++ b/tex/context/base/mkiv/data-met.lua
@@ -0,0 +1,141 @@
+if not modules then modules = { } end modules ['data-met'] = {
+    version   = 1.100,
+    comment   = "companion to luat-lib.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local find, format = string.find, string.format
+local sequenced = table.sequenced
+local addurlscheme, urlhashed = url.addscheme, url.hashed
+local getcurrentdir = lfs.currentdir
+
+local trace_locating = false
+local trace_methods  = false
+
+trackers.register("resolvers.locating", function(v) trace_methods = v end)
+trackers.register("resolvers.methods",  function(v) trace_methods = v end)
+
+--~ trace_methods = true
+
+local report_methods = logs.reporter("resolvers","methods")
+
+local allocate = utilities.storage.allocate
+
+local resolvers = resolvers
+
+local registered = { }
+
+local function splitmethod(filename) -- todo: filetype in specification
+    if not filename then
+        return { scheme = "unknown", original = filename }
+    end
+    if type(filename) == "table" then
+        return filename -- already split
+    end
+    filename = file.collapsepath(filename,".") -- hm, we should keep ./ in some cases
+
+    if not find(filename,"://",1,true) then
+        return { scheme = "file", path = filename, original = filename, filename = filename }
+    end
+    local specification = url.hashed(filename)
+    if not specification.scheme or specification.scheme == "" then
+        return { scheme = "file", path = filename, original = filename, filename = filename }
+    else
+        return specification
+    end
+end
+
+-- local function splitmethod(filename) -- todo: filetype in specification
+--     if not filename then
+--         return { scheme = "unknown", original = filename }
+--     end
+--     if type(filename) == "table" then
+--         return filename -- already split
+--     end
+--     return url.hashed(filename)
+-- end
+
+resolvers.splitmethod = splitmethod -- bad name but ok
+
+-- the second argument is always analyzed (saves time later on) and the original
+-- gets passed as original but also as argument
+
+local function methodhandler(what,first,...) -- filename can be nil or false
+    local method = registered[what]
+    if method then
+        local how, namespace = method.how, method.namespace
+        if how == "uri" or how == "url" then
+            local specification = splitmethod(first)
+            local scheme = specification.scheme
+            local resolver = namespace and namespace[scheme]
+            if resolver then
+                if trace_methods then
+                    report_methods("resolving, method %a, how %a, handler %a, argument %a",what,how,scheme,first)
+                end
+                return resolver(specification,...)
+            else
+                resolver = namespace.default or namespace.file
+                if resolver then
+                    if trace_methods then
+                        report_methods("resolving, method %a, how %a, handler %a, argument %a",what,how,"default",first)
+                    end
+                    return resolver(specification,...)
+                elseif trace_methods then
+                    report_methods("resolving, method %a, how %a, handler %a, argument %a",what,how,"unset")
+                end
+            end
+        elseif how == "tag" then
+            local resolver = namespace and namespace[first]
+            if resolver then
+                if trace_methods then
+                    report_methods("resolving, method %a, how %a, tag %a",what,how,first)
+                end
+                return resolver(...)
+            else
+                resolver = namespace.default or namespace.file
+                if resolver then
+                    if trace_methods then
+                        report_methods("resolving, method %a, how %a, tag %a",what,how,"default")
+                    end
+                    return resolver(...)
+                elseif trace_methods then
+                    report_methods("resolving, method %a, how %a, tag %a",what,how,"unset")
+                end
+            end
+        end
+    else
+        report_methods("resolving, invalid method %a")
+    end
+end
+
+resolvers.methodhandler = methodhandler
+
+function resolvers.registermethod(name,namespace,how)
+    registered[name] = { how = how or "tag", namespace = namespace }
+    namespace["byscheme"] = function(scheme,filename,...)
+        if scheme == "file" then
+            return methodhandler(name,filename,...)
+        else
+            return methodhandler(name,addurlscheme(filename,scheme),...)
+        end
+    end
+end
+
+local concatinators = allocate { notfound = file.join       }  -- concatinate paths
+local locators      = allocate { notfound = function() end  }  -- locate databases
+local hashers       = allocate { notfound = function() end  }  -- load databases
+local generators    = allocate { notfound = function() end  }  -- generate databases
+
+resolvers.concatinators = concatinators
+resolvers.locators      = locators
+resolvers.hashers       = hashers
+resolvers.generators    = generators
+
+local registermethod = resolvers.registermethod
+
+registermethod("concatinators",concatinators,"tag")
+registermethod("locators",     locators,     "uri")
+registermethod("hashers",      hashers,      "uri")
+registermethod("generators",   generators,   "uri")