Start every render from the zero hold set

This commit is contained in:
2026-09-28 18:45:07 +02:00
committed by Lillem4n
parent 1d73f1dc90
commit 1b9cf00a26
6 changed files with 12 additions and 17 deletions
+1 -1
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@@ -55,7 +55,7 @@ In [docs/decisions.md](docs/decisions.md):
- A render shares one reference draw per category, per group
- A draw group name is local to its category
- The expansion hold and the render's draws are two fences
- A record makes its draw maps up front, a `Fake` on its first read
- A hold set makes its draw maps on the first read
- A category never references itself, and a record's fences run at load
- A record's column set is fixed before the first draw
- Null is a `null` item, not a rate
+8 -7
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@@ -242,14 +242,15 @@ groups. They pin different things — an operand pins the value its own render p
and stops at a reference, a path pins every level it passes through — so one walk would
carry both rules and both scopes anyway, and tell them apart at every step.
## A record makes its draw maps up front, a `Fake` on its first read
## A hold set makes its draw maps on the first read
A record's columns always read through the render's draws, so making the maps where the
set is declared keeps them on that frame's stack. A `Fake` often reads no reference path
at all, and making them anyway cost about a fifth of the cheapest render, so it makes
them on the first read instead, at two heap allocations for a render that does share a
draw. The allocation gate over a repeat of a reference path and over a named draw group
prices that, and pins what keeps a hold set off the heap.
Every render starts from the zero `holdSet`, per goal 2's one spelling. Making the maps
where the set is declared kept a record's on its frame's stack, but a `Fake`'s set lives
on the `Generator`, so there it cost every render two heap allocations and about half the
cheapest one's time, measured 2026-09-28. Lazily, a render reading a reference path pays
those two allocations, a record or struct included, and one reading none pays nothing;
goal 11 holds either way. The allocation gate over a repeat of a reference path and over
a named draw group prices that, and pins what keeps a hold set off the heap.
## A category never references itself, and a record's fences run at load
-4
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@@ -20,10 +20,6 @@ type renderScope struct {
pins *pinSet
}
func eagerHoldSet() holdSet {
return holdSet{unnamed: hold{variant: map[string]node{}, value: map[string]readValue{}}}
}
// renderOnce renders n as one render, over a hold set of its own.
func renderOnce(s *session, n node) string {
var set holdSet
+2 -2
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@@ -130,7 +130,7 @@ func (f *Generator) FakeRecord(path string) (*Record, error) {
if err != nil {
return nil, fmt.Errorf("fejkdata: %s: %w", path, err)
}
set := eagerHoldSet()
var set holdSet
sc := renderScope{set: &set}
if t, isTable := n.(*table); isTable {
if n, err = tableRecord(f.rand, t, tail, sc); err != nil {
@@ -204,7 +204,7 @@ type RecordTemplate struct {
func (t *RecordTemplate) Fake() *Record {
t.g.mu.Lock()
defer t.g.mu.Unlock()
set := eagerHoldSet()
var set holdSet
return renderRecord(t.g.rand, t.template, t.columns, renderScope{set: &set})
}
+1 -1
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@@ -351,7 +351,7 @@ func (p *valueProof) checkField(label string, ft reflect.Type, column node) erro
// fill draws the record into v's tagged fields, then each nested struct as a record of its own.
func (s *structShape) fill(sess *session, v reflect.Value) {
if s.record != nil {
set := eagerHoldSet()
var set holdSet
for i, c := range renderRecord(sess, s.record, s.columns, renderScope{set: &set}).columns {
setColumn(fieldAt(v, s.fieldIndexes[i]), c)
}
-2
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@@ -21,8 +21,6 @@ Self-sufficiency 5.6), every seat capped by Locality, and all nine naming
This round, in order:
- Start every render from one spelling of an empty hold set: `Fake` uses
`holdSet{}`, the record and struct paths `eagerHoldSet()`.
- Correct the false comments: `funcCall` names `checkFunc` where `parseFormat`
reports, `struct.go`'s "t sits at index within c.t" names no field, `recordFormats`
calls ndjson "the same column", `Generator` says every other entry point takes `mu`