Merge pull request #16 from FindHotel/reduce-optional-allocations

Reduce allocations and the footprint
parsyl · Aug 19, 2021 · 7a7a3ff · 7a7a3ff
2 parents 55e4ae2 + ec68c44
commit 7a7a3ff
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Showing 21 changed files with 698 additions and 535 deletions.
diff --git a/cmd/bitpackgen/main.go b/cmd/bitpackgen/main.go
@@ -159,18 +159,20 @@ var (
 
 // Code generated by github.com/parsyl/parquet.  DO NOT EDIT.
 
-func Pack(width int, vals []uint8) []byte {
+const MaxSize = {{.Max}}
+
+func Pack(b []byte, width int, vals []uint8) []byte {
 	switch width {
 		{{range $i := N 1 .Max }}case {{$i}}:
-			return pack{{$i}}(vals)
+			return pack{{$i}}(b, vals)
 		{{end}}default:
-			return []byte{}
+			return b
 	}
 }
 
 {{range $i := N 1 .Max}}
-func pack{{$i}}(vals []uint8) []byte {
-return []byte{ {{template "bytes" $i}} }
+func pack{{$i}}(b []byte, vals []uint8) []byte {
+return append(b, {{template "bytes" $i}} )
 }
 {{end}}
 

diff --git a/cmd/parquetgen/dremel/read.go b/cmd/parquetgen/dremel/read.go
@@ -18,7 +18,8 @@ func readOptional(f fields.Field) string {
 	n := f.MaxDef()
 	for def := 0; def < n; def++ {
 		out += fmt.Sprintf(`case x.%s == nil:
-			return nil, []uint8{%d}, nil
+			defs = append(defs, %d)
+			return vals, defs, reps
 	`, nilField(def, f), def)
 	}
 
@@ -29,13 +30,15 @@ func readOptional(f fields.Field) string {
 	}
 
 	out += fmt.Sprintf(`	default:
-			return []%s{%sx.%s}, []uint8{%d}, nil`, cleanTypeName(f.Type), ptr, nilField(n, f), n)
+			vals = append(vals, %sx.%s)
+			defs = append(defs, %d)
+			return vals, defs, reps`, ptr, nilField(n, f), n)
 
-	return fmt.Sprintf(`func read%s(x %s) ([]%s, []uint8, []uint8) {
+	return fmt.Sprintf(`func read%s(x %s, vals []%s, defs, reps []uint8) ([]%s, []uint8, []uint8) {
 		switch {
 		%s
 		}
-	}`, strings.Join(f.FieldNames(), ""), f.StructType(), cleanTypeName(f.Type), out)
+	}`, strings.Join(f.FieldNames(), ""), f.StructType(), cleanTypeName(f.Type), cleanTypeName(f.Type), out)
 }
 
 func cleanTypeName(s string) string {

diff --git a/cmd/parquetgen/dremel/read_repeated.go b/cmd/parquetgen/dremel/read_repeated.go
@@ -60,9 +60,7 @@ type readClause struct {
 }
 
 func readRepeated(f fields.Field) string {
-	return fmt.Sprintf(`func read%s(x %s) ([]%s, []uint8, []uint8) {
-	var vals []%s
-	var defs, reps []uint8
+	return fmt.Sprintf(`func read%s(x %s, vals []%s, defs, reps []uint8) ([]%s, []uint8, []uint8) {
 	var lastRep uint8
 
 	%s