package ent import ( "fmt" "io" "sort" "github.com/jordanorelli/hyperstone/bit" ) type node interface { weight() int rank() int } // intermediate node type iNode struct { left node right node _rank int } func (n iNode) String() string { return fmt.Sprintf("{%d %d *}", n.left.weight()+n.right.weight(), n.rank()) } func (n iNode) weight() int { return n.left.weight() + n.right.weight() } func (n iNode) rank() int { return n._rank } // leaf node type lNode struct { name string _rank int freq int fn selectionOp } func (n lNode) String() string { return fmt.Sprintf("{%d %d %s}", n.freq, n._rank, n.name) } func (n lNode) weight() int { return n.freq } func (n lNode) rank() int { return n._rank } // three-way comparison for nodes, used in sorting func n_compare(n1, n2 node) int { switch { case n1.weight() < n2.weight(): return -1 case n1.weight() > n2.weight(): return 1 case n1.rank() < n2.rank(): return 1 case n1.rank() > n2.rank(): return -1 default: return 0 } } // joins two nodes, creating and returning their parent node func n_join(n1, n2 node, rank int) node { switch n_compare(n1, n2) { case -1: return iNode{n1, n2, rank} case 0, 1: return iNode{n2, n1, rank} default: panic("not reached") } } // a list of huffman nodes, for assembling a huffman tree type nodeList []node func (l nodeList) Len() int { return len(l) } func (l nodeList) Less(i, j int) bool { return n_compare(l[i], l[j]) == -1 } func (l nodeList) Swap(i, j int) { l[i], l[j] = l[j], l[i] } func makeTree(l nodeList) node { // at each step: // sort the list of nodes in the tree. // remove the last two nodes, joining them to create their parent node. // append this parent node to the list of nodes. // repeat until only one node remains, which is the root node. for rank := len(l); len(l) > 1; rank++ { sort.Sort(sort.Reverse(l)) l = append(l[:len(l)-2], n_join(l[len(l)-2], l[len(l)-1], rank)) } return l[0] } // walks the huffman tree rooted at the node n, returning the selection op // encoded by the tree. func walk(n node, br bit.Reader) selectionOp { switch v := n.(type) { case lNode: // Debug.Printf("fieldpath fn: %s", v.name) return v.fn case iNode: if bit.ReadBool(br) { return walk(v.right, br) } else { return walk(v.left, br) } default: panic("not reached") } } func dump(n node, prefix string, w io.Writer) { switch v := n.(type) { case lNode: fmt.Fprintf(w, "%s\t%v\n", prefix, v) case iNode: dump(v.left, prefix+"0", w) dump(v.right, prefix+"1", w) } } var hlist = nodeList{ lNode{"PlusOne", 0, 36271, func(r *selectionReader, br bit.Reader) { r.add(1) }}, lNode{"FieldPathEncodeFinish", 39, 25474, nil}, lNode{"PushOneLeftDeltaNRightNonZeroPack6Bits", 11, 10530, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushOneLeftDeltaNRightNonZeroPack6Bits") }}, lNode{"PlusTwo", 1, 10334, func(r *selectionReader, br bit.Reader) { r.add(2) }}, lNode{"PlusN", 4, 4128, func(r *selectionReader, br bit.Reader) { r.add(int(bit.ReadUBitVarFP(br)) + 5) }}, lNode{"PushOneLeftDeltaOneRightNonZero", 8, 2942, func(r *selectionReader, br bit.Reader) { Debug.Printf("PushOneLeftDeltaOneRightNonZero") r.add(1) r.push(int(bit.ReadUBitVarFP(br))) }}, lNode{"PopAllButOnePlusOne", 29, 1837, func(r *selectionReader, br bit.Reader) { r.pop(-1) r.add(1) }}, lNode{"PlusThree", 2, 1375, func(r *selectionReader, br bit.Reader) { r.add(3) }}, lNode{"PlusFour", 3, 646, func(r *selectionReader, br bit.Reader) { panic("not implemented: PlusFour") }}, lNode{"PopAllButOnePlusNPack6Bits", 32, 634, func(r *selectionReader, br bit.Reader) { r.pop(-1) r.add(int(br.ReadBits(6)) + 1) }}, lNode{"PushOneLeftDeltaNRightZero", 9, 560, func(r *selectionReader, br bit.Reader) { r.add(int(bit.ReadUBitVarFP(br))) r.push(0) }}, lNode{"PushOneLeftDeltaOneRightZero", 7, 521, func(r *selectionReader, br bit.Reader) { r.add(1) r.push(0) }}, lNode{"PushOneLeftDeltaNRightNonZero", 10, 471, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushOneLeftDeltaNRightNonZero") }}, lNode{"PushNAndNonTopological", 26, 310, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushNAndNonTopological") }}, lNode{"PopAllButOnePlusNPack3Bits", 31, 300, func(r *selectionReader, br bit.Reader) { panic("not implemented: PopAllButOnePlusNPack3Bits") }}, lNode{"NonTopoPenultimatePlusOne", 37, 271, func(r *selectionReader, br bit.Reader) { panic("not implemented: NonTopoPenultimatePlusOne") }}, lNode{"PushOneLeftDeltaNRightNonZeroPack8Bits", 12, 251, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushOneLeftDeltaNRightNonZeroPack8Bits") }}, lNode{"PopAllButOnePlusN", 30, 149, func(r *selectionReader, br bit.Reader) { r.pop(-1) r.add(int(bit.ReadUBitVarFP(br)) + 1) }}, lNode{"NonTopoComplexPack4Bits", 38, 99, func(r *selectionReader, br bit.Reader) { r.måp(func(i int) int { if bit.ReadBool(br) { return i + int(br.ReadBits(4)) - 7 // ?! } return i }) }}, lNode{"NonTopoComplex", 36, 76, func(r *selectionReader, br bit.Reader) { r.måp(func(i int) int { if bit.ReadBool(br) { return i + int(bit.ReadZigZag32(br)) } return i }) }}, lNode{"PushOneLeftDeltaZeroRightZero", 5, 35, func(r *selectionReader, br bit.Reader) { r.push(0) }}, lNode{"PushOneLeftDeltaZeroRightNonZero", 6, 3, func(r *selectionReader, br bit.Reader) { r.push(int(bit.ReadUBitVarFP(br))) }}, lNode{"PopOnePlusOne", 27, 2, func(r *selectionReader, br bit.Reader) { r.pop(1) r.add(1) }}, lNode{"PopNAndNonTopographical", 35, 1, func(r *selectionReader, br bit.Reader) { r.count -= int(bit.ReadUBitVarFP(br)) r.måp(func(i int) int { if bit.ReadBool(br) { return i + int(bit.ReadZigZag32(br)) } return i }) }}, // all the other operations have weights of 0 in clarity, which makes no // sense. lNode{"PopNPlusN", 34, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PopNPlusN") }}, lNode{"PopNPlusOne", 33, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PopNPlusOne") }}, lNode{"PopOnePlusN", 28, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PopOnePlusN") }}, lNode{"PushN", 25, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushN") }}, lNode{"PushThreePack5LeftDeltaN", 24, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushThreePack5LeftDeltaN") }}, lNode{"PushThreeLeftDeltaN", 23, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushThreeLeftDeltaN") }}, lNode{"PushTwoPack5LeftDeltaN", 22, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushTwoPack5LeftDeltaN") }}, lNode{"PushTwoLeftDeltaN", 21, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushTwoLeftDeltaN") }}, lNode{"PushThreePack5LeftDeltaOne", 20, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushThreePack5LeftDeltaOne") }}, lNode{"PushThreeLeftDeltaOne", 19, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushThreeLeftDeltaOne") }}, lNode{"PushTwoPack5LeftDeltaOne", 18, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushTwoPack5LeftDeltaOne") }}, lNode{"PushTwoLeftDeltaOne", 17, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushTwoLeftDeltaOne") }}, lNode{"PushThreePack5LeftDeltaZero", 16, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushThreePack5LeftDeltaZero") }}, lNode{"PushThreeLeftDeltaZero", 15, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushThreeLeftDeltaZero") }}, lNode{"PushTwoPack5LeftDeltaZero", 14, 1, func(r *selectionReader, br bit.Reader) { r.push(int(br.ReadBits(5))) r.push(int(br.ReadBits(5))) }}, lNode{"PushTwoLeftDeltaZero", 13, 1, func(r *selectionReader, br bit.Reader) { panic("not implemented: PushTwoLeftDeltaZero") }}, } var huffRoot = makeTree(hlist)