Rewrite tree-pruning algorithm

I was experiencing trouble from collapsing C functions that called
Julia functions. This rewrites the algorithm so it progresses first
to the leaves and then works its way back inwards.

LICENSE.txt

@@ -0,0 +1,8 @@
+The MIT License (MIT)
+Copyright (c) 2013 Timothy E. Holy
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

src/ProfileView.jl

@@ -9,7 +9,7 @@ using .PVTree
 using Tk, Color, Base.Graphics
 import Cairo
 
-import Base: isequal, show
+import Base: contains, isequal, show
 
 # TODO: implement zoom
 
@@ -56,10 +56,28 @@ function view(data = Profile.fetch(); C = false, colorgc = true, fontsize = 12,
     w = sum(counts)
     root = Tree.Node(PVData(1:w))
     PVTree.buildgraph!(root, bt, counts, 0, ip2so, so2ip, lidict)
+    PVTree.setstatus!(root, isgc)
 #     Tree.showedges(STDOUT, root, x -> string(get(lidict, x.ip, "root"), ", hspan = ", x.hspan, ", status = ", x.status))
-    PVTree.prunegraph!(root, C, isjl, isgc)
+#     Tree.showedges(STDOUT, root, x -> string(get(lidict, x.ip, "root"), ", status = ", x.status))
+#     Tree.showedges(STDOUT, root, x -> x.status == 0 ? nothing : string(get(lidict, x.ip, "root"), ", status = ", x.status))
+#     checkidentity(ip2so, so2ip)
+#     checkcontains(root, ip2so, so2ip, lidict)
+#     checkstatus(root, isgc, isjl, C, lidict)
+    counts = zeros(Int, length(uip))
+    if !C
+        PVTree.prunegraph!(root, isjl, lidict, ip2so, counts)
+    end
+#     for ip in uip
+#         println(counts[ip2so[ip]], ": ", lidict[ip])
+#     end
+#     if !C
+#         havegc = any([isgc[ip] for ip in uip])
+#         if havegc
+#             @assert checkprunedgc(root, false)
+#         end
+#     end
 #     println("\nPruned:")
-#     Tree.showedges(STDOUT, root, x -> string(get(lidict, x.ip, "root"), " status = ", x.status))
+#     Tree.showedges(STDOUT, root, x -> string(get(lidict, x.ip, "root"), ", status = ", x.status))
     # Generate a "tagged" image
     rowtags = {fill(TAGNONE, w)}
     buildtags!(rowtags, root, 1)
@@ -167,7 +185,6 @@ function buildimg(imgtags, colors, bkg, gccolor, colorgc::Bool, combine::Bool, l
         for i = 1:w
             t = imgtags[i,j]
             if t != TAGNONE
-                status |= t.status
                 if t != lasttag && (lasttag == TAGNONE || !(combine && lidict[lasttag.ip] == lidict[t.ip]))
                     if first != 0
                         colorindex = fillrow!(img, j, first:i-1, colorindex, colorlen, nextcolor, gccolor, status & colorgc)
@@ -176,6 +193,8 @@ function buildimg(imgtags, colors, bkg, gccolor, colorgc::Bool, combine::Bool, l
                     end
                     first = i
                     lasttag = t
+                else
+                    status |= t.status
                 end
             else
                 if first != 0
@@ -205,4 +224,72 @@ function fillrow!(img, j, rng::Range1{Int}, colorindex, colorlen, regcolor, gcco
     end
 end
 
+#### Debugging code
+
+function checkidentity(ip2so, so2ip)
+    for (k,v) in ip2so
+        @assert so2ip[v] == k
+    end
+end
+
+function checkcontains(root, ip2so, so2ip, lidict)
+    flag = contains(root, ip2so)
+    if !all(flag)
+        missing = find(!flag)
+        println("missing ips:")
+        for i in missing
+            @show i
+            @show so2ip[i]
+            println(lidict[so2ip[i]])
+        end
+        error("Internal error: the tree does not contain all ips")
+    end
+end
+
+# This skips the parent, gets everything else
+# (to avoid a problem with root with ip=0)
+function contains(parent::Node, ip2so::Dict)
+    ret = Array(Bool, 0)
+    contains!(ret, parent, ip2so)
+    @show length(ip2so)
+    @show length(ret)
+    return ret
+end
+
+function contains!(ret, parent::Node, ip2so::Dict)
+    for c in parent
+        indx = ip2so[c.data.ip]
+        setindexsafe!(ret, indx, true)
+        contains!(ret, c, ip2so)
+    end
+end
+
+function setindexsafe!(a, i::Integer, val)
+    if i > length(a)
+        insert!(a, i, val)
+    else
+        a[i] = val
+    end
+end
+
+function checkstatus(parent::Node, isgc::Dict, isjl::Dict, C, lidict)
+    if isgc[parent.data.ip] && parent.data.status == 0
+            @show lidict[parent.data.ip]
+            error("gc should be set, and it isn't")
+    end
+    for c in parent
+        checkstatus(c, isgc, isjl, C, lidict)
+    end
+end
+
+function checkprunedgc(parent::Node, tf::Bool)
+    tf |= parent.data.status > 0
+    if !tf
+        for c in parent
+            tf = checkprunedgc(c, tf)
+        end
+    end
+    tf
+end
+
 end

src/pvtree.jl

@@ -80,43 +80,57 @@ function buildgraph!(parent::Node, bt::Vector{Vector{Uint}}, counts::Vector{Int}
     end
 end
 
-# Updates the status and, if C == false, prunes any "C" children
-function prunegraph!(parent::Node, C::Bool, isjl::Dict, isgc::Dict)
-    pisjl = isjl[parent.data.ip]
-    firstchild = true
-    prevchild = parent.child
+function setstatus!(parent::Node, isgc::Dict)
+    if isgc[parent.data.ip]
+        parent.data.status = 1
+    end
     for c in parent
-        if isgc[c.data.ip] && (pisjl || !C)
-            parent.data.status = 1  # marks parent as triggering garbage collection
-        end
-        if !C
-            newc = prunegraph!(c, C, isjl, isgc)
-            if newc != parent
-                # newc is a valid child
-                if firstchild
-                    parent.child = newc
-                    firstchild = false
+        setstatus!(c, isgc)
+    end
+end
+
+# The last three inputs are just for debugging
+function prunegraph!(parent::Node, isjl::Dict, lidict, ip2so, counts)
+    if parent.data.ip != 0
+        counts[ip2so[parent.data.ip]] += 1
+    end
+    c = parent.child
+    if parent == c
+        return
+    end
+    parent.child = parent  # mark as a leaf unless we keep some children
+    lastc = c
+    isfirst = true
+    while true
+        prunegraph!(c, isjl, lidict, ip2so, counts)
+        if !isjl[c.data.ip]
+            parent.data.status |= c.data.status
+            if !isleaf(c)
+                # It has Julia children, splice them in
+                if isfirst
+                    parent.child = c.child
+                    isfirst = false
                 else
-                    prevchild.sibling = newc
+                    lastc.sibling = c.child
                 end
-                # one child might have become several children
-                prevchild = (newc == c) ? newc : lastsibling(newc)
-            elseif firstchild
-                # mark it tentatively as a leaf so it can be clipped
-                parent.child = parent
+                lastc = lastsibling(c.child)
             end
-        end
-    end
-    if !C && !pisjl
-        if isleaf(parent)
-            # Prune entirely
-            parent.parent.data.status |= parent.data.status
-            return parent.parent
         else
-            return parent.child
+            if isfirst
+                parent.child = c
+            else
+                lastc.sibling = c
+            end
+            isfirst = false
+            lastc = c
+        end
+        if c.sibling == c
+            lastc.sibling = lastc.sibling
+            break
         end
+        c = c.sibling
     end
-    parent
 end
 
+
 end

src/tree.jl

@@ -9,7 +9,7 @@ export Node,
     isleaf,
     lastsibling
 
-# Tree representation:
+# "Left-child, right-sibling" tree representation:
 # Suppose a particular node, "A", has 3 children, "a", "b", and "c".
 #     "a", "b", and "c" link to "A" as their parent.
 #     "A" links "a" as its child; "a" links "b" as its sibling, and "b" links "c" as its sibling.
@@ -85,16 +85,19 @@ done(n::Node, state::Node) = n == state
 next(n::Node, state::Node) = state, state == state.sibling ? n : state.sibling
 
 function showedges(io::IO, parent::Node, printfunc = identity)
-    if isleaf(parent)
-        println(io, printfunc(parent.data), " has no children")
-    else
-        print(io, printfunc(parent.data), " has the following children: ")
-        for c in parent
-            print(io, printfunc(c.data), "    ")
-        end
-        print(io, "\n")
-        for c in parent
-            showedges(io, c, printfunc)
+    str = printfunc(parent.data)
+    if str != nothing
+        if isleaf(parent)
+            println(io, str, " has no children")
+        else
+            print(io, str, " has the following children: ")
+            for c in parent
+                print(io, printfunc(c.data), "    ")
+            end
+            print(io, "\n")
+            for c in parent
+                showedges(io, c, printfunc)
+            end
         end
     end
 end

test/pvtree.jl

@@ -31,7 +31,8 @@ end
 
 # Run it with C == false
 root = buildraw()
-PVTree.prunegraph!(root, false, isjl, isgc)
+PVTree.setstatus!(root, isgc)
+PVTree.prunegraph!(root, isjl)
 
 @assert root.data.status == 1
 c = root.child
@@ -50,13 +51,14 @@ c = c.sibling
 
 # Now do it again, with C == true
 root = buildraw()
-PVTree.prunegraph!(root, true, isjl, isgc)
+PVTree.setstatus!(root, isgc)
+# PVTree.prunegraph!(root, isjl)
 
 @assert root.data.status == 0
 c = root.child
 c1 = c
 @assert c.data.ip == 1
-@assert c.data.status == 1
+@assert c.data.status == 0
 c = c.sibling
 @assert c.data.ip == 2
 @assert c.data.status == 0
@@ -77,5 +79,6 @@ c = c.sibling
 @assert c == c.sibling
 c = c1.child
 @assert c.data.ip == 7
+@assert c.data.status == 1
 @assert Tree.isleaf(c)
 @assert c == c.sibling