2016-01-12 16:26:00

1 files changed, 165 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/node-mig.lua b/tex/context/base/mkiv/node-mig.lua
new file mode 100644
index 000000000..24bebb0cc
--- /dev/null
+++ b/tex/context/base/mkiv/node-mig.lua
@@ -0,0 +1,165 @@
+if not modules then modules = { } end modules ['node-mig'] = {
+    version   = 1.001,
+    comment   = "companion to node-mig.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- todo: insert_after
+
+local format = string.format
+
+local trace_migrations = false trackers.register("nodes.migrations", function(v) trace_migrations = v end)
+
+local report_nodes = logs.reporter("nodes","migrations")
+
+local attributes    = attributes
+local nodes         = nodes
+local tasks         = nodes.tasks
+
+local nuts          = nodes.nuts
+local tonut         = nuts.tonut
+
+local getnext       = nuts.getnext
+local getid         = nuts.getid
+local getlist       = nuts.getlist
+local getattr       = nuts.getattr
+
+local setfield      = nuts.setfield
+local setattr       = nuts.setattr
+local setlink       = nuts.setlink
+local setlist       = nuts.setlist
+local setprev       = nuts.setprev
+local setnext       = nuts.setnext
+
+local remove_node   = nuts.remove
+
+local nodecodes     = nodes.nodecodes
+local hlist_code    = nodecodes.hlist
+local vlist_code    = nodecodes.vlist
+local insert_code   = nodecodes.ins
+local mark_code     = nodecodes.mark
+
+local a_migrated    = attributes.private("migrated")
+
+local migrate_inserts, migrate_marks, inserts_too
+
+local t_inserts, t_marks, t_sweeps = 0, 0, 0
+
+local function locate(head,first,last,ni,nm)
+    local current = head
+    while current do
+        local id = getid(current)
+        if id == vlist_code or id == hlist_code then
+            local list = getlist(current)
+            if list then
+                list, first, last, ni, nm = locate(list,first,last,ni,nm)
+                setlist(current,list)
+            end
+            current = getnext(current)
+        elseif migrate_inserts and id == insert_code then
+            local insert
+            head, current, insert = remove_node(head,current)
+            setnext(insert)
+            if first then
+                setlink(last,insert)
+            else
+                setprev(insert)
+                first = insert
+            end
+            last = insert
+            ni = ni + 1
+        elseif migrate_marks and id == mark_code then
+            local mark
+            head, current, mark = remove_node(head,current)
+            setnext(mark)
+            if first then
+                setlink(last,mark)
+            else
+                setprev(mark)
+                first = mark
+            end
+            last = mark
+            nm = nm + 1
+        else
+            current = getnext(current)
+        end
+    end
+    return head, first, last, ni, nm
+end
+
+function nodes.handlers.migrate(head,where)
+    local done = false
+    if head then
+        if trace_migrations then
+            report_nodes("migration sweep %a",where)
+        end
+        local current = tonut(head)
+        while current do
+            local id = getid(current)
+            -- inserts_too is a temp hack, we should only do them when it concerns
+            -- newly placed (flushed) inserts
+            if id == vlist_code or id == hlist_code or (inserts_too and id == insert_code) and not getattr(current,a_migrated) then
+                setattr(current,a_migrated,1)
+                t_sweeps = t_sweeps + 1
+                local h = getlist(current)
+                local first, last, ni, nm
+                while h do
+                    local id = getid(h)
+                    if id == vlist_code or id == hlist_code then
+                        h, first, last, ni, nm = locate(h,first,last,0,0)
+                    end
+                    h = getnext(h)
+                end
+                if first then
+                    t_inserts = t_inserts + ni
+                    t_marks = t_marks + nm
+                    if trace_migrations and (ni > 0 or nm > 0) then
+                        report_nodes("sweep %a, container %a, %s inserts and %s marks migrated outwards during %a",
+                            t_sweeps,nodecodes[id],ni,nm,where)
+                    end
+                    -- inserts after head, use insert_after
+                    local n = getnext(current)
+                    if n then
+                        setlink(last,n)
+                    end
+                    setlink(current,first)
+                    done = true
+                    current = last
+                end
+            end
+            current = getnext(next)
+        end
+        return head, done
+    end
+end
+
+-- for the moment this way, this will disappear
+
+experiments.register("marks.migrate", function(v)
+    if v then
+        tasks.enableaction("mvlbuilders", "nodes.handlers.migrate")
+    end
+    migrate_marks = v
+end)
+
+experiments.register("inserts.migrate", function(v)
+    if v then
+        tasks.enableaction("mvlbuilders", "nodes.handlers.migrate")
+    end
+    migrate_inserts = v
+end)
+
+experiments.register("inserts.migrate.nested", function(v)
+    if v then
+        tasks.enableaction("mvlbuilders", "nodes.handlers.migrate")
+    end
+    inserts_too = v
+end)
+
+statistics.register("node migrations", function()
+    if trace_migrations and t_sweeps > 0 then
+        return format("%s sweeps, %s inserts moved, %s marks moved",t_sweeps,t_inserts,t_marks)
+    end
+end)