Files
go-toml/internal/ast/builder.go
T
Thomas Pelletier 390927a0cd Reuse AST storage between top-level expressions
```
Comparing:
	old: v2-wip/1da2fc7 (2021-03-25 20:38:05 -0400 -0400)
	run: v2-wip/3f23ab9 (2021-03-25 22:35:06 -0400 -0400)
-----------------------------------------------------------
name                  old time/op    new time/op    delta
UnmarshalSimple/v2-8     700ns ± 3%     705ns ± 2%     ~     (p=0.690 n=5+5)
UnmarshalSimple/v1-8    3.85µs ± 1%    4.02µs ± 4%   +4.19%  (p=0.032 n=5+5)
UnmarshalSimple/bs-8    2.34µs ± 2%    2.38µs ± 3%     ~     (p=0.310 n=5+5)
ReferenceFile/v2-8      32.2µs ±13%    23.9µs ± 1%  -25.79%  (p=0.008 n=5+5)
ReferenceFile/v1-8       270µs ± 2%     264µs ± 2%     ~     (p=0.095 n=5+5)
ReferenceFile/bs-8       291µs ± 0%     294µs ± 0%   +0.88%  (p=0.008 n=5+5)

name                  old alloc/op   new alloc/op   delta
ReferenceFile/v2-8      37.1kB ± 0%     6.7kB ± 0%  -81.91%  (p=0.008 n=5+5)
ReferenceFile/v1-8       131kB ± 0%     131kB ± 0%     ~     (p=0.444 n=5+5)
ReferenceFile/bs-8      80.8kB ± 0%    80.8kB ± 0%     ~     (p=0.571 n=5+5)

name                  old allocs/op  new allocs/op  delta
ReferenceFile/v2-8         152 ± 0%       148 ± 0%   -2.63%  (p=0.008 n=5+5)
ReferenceFile/v1-8       2.65k ± 0%     2.65k ± 0%     ~     (all equal)
ReferenceFile/bs-8       1.73k ± 0%     1.73k ± 0%     ~     (all equal)

~/s/g/p/g/benchmark$ go test -bench=.
goos: linux
goarch: amd64
pkg: github.com/pelletier/go-toml/v2/benchmark
cpu: Intel(R) Core(TM) i7-7700 CPU @ 3.60GHz
BenchmarkUnmarshalSimple/v2-8         	 1692444	       710.7 ns/op
BenchmarkUnmarshalSimple/v1-8         	  307609	      3862 ns/op
BenchmarkUnmarshalSimple/bs-8         	  520429	      2285 ns/op
BenchmarkReferenceFile/v2-8           	   50395	     24006 ns/op	    6704 B/op	     148 allocs/op
BenchmarkReferenceFile/v1-8           	    4144	    264655 ns/op	  130567 B/op	    2649 allocs/op
BenchmarkReferenceFile/bs-8           	    3969	    293635 ns/op	   80784 B/op	    1729 allocs/op
PASS
ok  	github.com/pelletier/go-toml/v2/benchmark	8.143s
```
2021-03-25 22:37:16 -04:00

61 lines
1.0 KiB
Go

package ast
type Reference struct {
idx int
set bool
}
func (r Reference) Valid() bool {
return r.set
}
type Builder struct {
tree Root
lastIdx int
}
func (b *Builder) Tree() *Root {
return &b.tree
}
func (b *Builder) NodeAt(ref Reference) Node {
return b.tree.at(ref.idx)
}
func (b *Builder) Reset() {
b.tree.nodes = b.tree.nodes[:0]
b.lastIdx = 0
}
func (b *Builder) Push(n Node) Reference {
n.root = &b.tree
b.lastIdx = len(b.tree.nodes)
b.tree.nodes = append(b.tree.nodes, n)
return Reference{
idx: b.lastIdx,
set: true,
}
}
func (b *Builder) PushAndChain(n Node) Reference {
n.root = &b.tree
newIdx := len(b.tree.nodes)
b.tree.nodes = append(b.tree.nodes, n)
if b.lastIdx >= 0 {
b.tree.nodes[b.lastIdx].next = newIdx
}
b.lastIdx = newIdx
return Reference{
idx: b.lastIdx,
set: true,
}
}
func (b *Builder) AttachChild(parent Reference, child Reference) {
b.tree.nodes[parent.idx].child = child.idx
}
func (b *Builder) Chain(from Reference, to Reference) {
b.tree.nodes[from.idx].next = to.idx
}