2016-06-08 10:54:00

1 files changed, 68 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/grph-mem.lua b/tex/context/base/mkiv/grph-mem.lua
new file mode 100644
index 000000000..80a6bfdbf
--- /dev/null
+++ b/tex/context/base/mkiv/grph-mem.lua
@@ -0,0 +1,68 @@
+if not modules then modules = { } end modules ['grph-mem'] = {
+    version   = 1.001,
+    comment   = "companion to grph-inc.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- very experimental and likely to change
+--
+-- \startluacode
+--     figures.setmemstream("whatever",io.loaddata("t:/sources/cow.pdf"))
+-- \stopluacode
+--
+-- \externalfigure[memstream:///t:/sources/cow.pdf]
+-- \externalfigure[memstream:///whatever]
+
+local report = logs.reporter("memstream")
+local data   = { }
+local trace  = false
+
+function resolvers.finders.memstream(specification)
+    local original   = specification.original
+    local identifier = data[original]
+    if identifier then
+        if trace then
+            report("reusing %a",identifier)
+        end
+        return identifier
+    end
+    local stream = io.loaddata(specification.path)
+    if not stream or stream == "" then
+        return resolvers.finders.notfound()
+    end
+    local memstream  = { epdf.openMemStream(stream,#stream,original) }
+    local identifier = memstream[2]
+    if not identifier then
+        report("invalid %a",name)
+        identifier = "invalid-memstream"
+    elseif trace then
+        report("using %a",identifier)
+    end
+    data[original]   = identifier
+    return identifier
+end
+
+function resolvers.setmemstream(name,stream)
+    local original   = "memstream:///" .. name
+    local memstream  = { epdf.openMemStream(stream,#stream,original) }
+    local identifier = memstream[2]
+    if not identifier then
+        report("invalid %a",name)
+        identifier = "invalid-memstream"
+    elseif trace then
+        report("setting %a",identifier)
+    end
+    data[original] = identifier
+end
+
+figures.identifiers.list[#figures.identifiers.list+1] = function(specification)
+    local name = specification.request.name
+    if name and data[name] then
+        specification.status.status = 1
+        specification.used.fullname = name
+    end
+end
+
+figures.setmemstream = resolvers.setmemstream