From 41f40b7f947ba0a2fe75d813f57dee1716ff127b Mon Sep 17 00:00:00 2001
From: Mattias Wadman <mattias.wadman@gmail.com>
Date: Wed, 14 Jun 2023 17:46:50 +0200
Subject: [PATCH] interp: Add to binary fast path for arrays with only 0-255
 numbers and strings

---
 pkg/interp/binary.go              | 44 ++++++++++++++++++++++++++++++-
 pkg/interp/testdata/binary.fqtest |  3 +++
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/pkg/interp/binary.go b/pkg/interp/binary.go
index 0606b05800..f4f2d5b740 100644
--- a/pkg/interp/binary.go
+++ b/pkg/interp/binary.go
@@ -45,6 +45,13 @@ func ToBitReader(v any) (bitio.ReaderAtSeeker, error) {
 	return toBitReaderEx(v, false)
 }
 
+type byteRangeError int
+
+func (b byteRangeError) Error() string {
+	return fmt.Sprintf("byte in binary list must be bytes (0-255) got %d", int(b))
+
+}
+
 func toBitReaderEx(v any, inArray bool) (bitio.ReaderAtSeeker, error) {
 	switch vv := v.(type) {
 	case ToBinary:
@@ -63,7 +70,7 @@ func toBitReaderEx(v any, inArray bool) (bitio.ReaderAtSeeker, error) {
 
 		if inArray {
 			if bi.Cmp(big.NewInt(255)) > 0 || bi.Cmp(big.NewInt(0)) < 0 {
-				return nil, fmt.Errorf("byte in binary list must be bytes (0-255) got %v", bi)
+				return nil, byteRangeError(bi.Int64())
 			}
 			n := bi.Uint64()
 			b := [1]byte{byte(n)}
@@ -86,6 +93,41 @@ func toBitReaderEx(v any, inArray bool) (bitio.ReaderAtSeeker, error) {
 		return br, nil
 	case []any:
 		rr := make([]bitio.ReadAtSeeker, 0, len(vv))
+
+		// fast path for slice containing only 0-255 numbers and strings
+		bs := &bytes.Buffer{}
+		for _, e := range vv {
+			if bs == nil {
+				break
+			}
+			switch ev := e.(type) {
+			case int:
+				if ev >= 0 && ev <= 255 {
+					bs.WriteByte(byte(ev))
+					continue
+				}
+			case float64:
+				b := int(ev)
+				if b >= 0 && b <= 255 {
+					bs.WriteByte(byte(ev))
+					continue
+				}
+			case *big.Int:
+				if ev.Cmp(big.NewInt(0)) >= 0 && ev.Cmp(big.NewInt(255)) <= 0 {
+					bs.WriteByte(byte(ev.Uint64()))
+					continue
+				}
+			case string:
+				// TODO: maybe only if less then some length?
+				bs.WriteString(ev)
+				continue
+			}
+			bs = nil
+		}
+		if bs != nil {
+			return bitio.NewBitReader(bs.Bytes(), -1), nil
+		}
+
 		// TODO: optimize byte array case, flatten into one slice
 		for _, e := range vv {
 			eBR, eErr := toBitReaderEx(e, true)
diff --git a/pkg/interp/testdata/binary.fqtest b/pkg/interp/testdata/binary.fqtest
index 28fe8952ab..359b5b5500 100644
--- a/pkg/interp/testdata/binary.fqtest
+++ b/pkg/interp/testdata/binary.fqtest
@@ -56,6 +56,9 @@ mp3> [1, 2, 3, [1, 2, 3]] | tobytes
 mp3> [1, 2, 3, [1, 2, 3], .headers[0].header.magic] | tobytes
    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|
 0x0|01 02 03 01 02 03 49 44 33|                    |......ID3|      |.: raw bits 0x0-0x8.7 (9)
+mp3> [0,"abc",1,2.1] | tobytes
+   |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|
+0x0|00 61 62 63 01 02|                             |.abc..|         |.: raw bits 0x0-0x5.7 (6)
 mp3> [-1] | tobytes
 error: byte in binary list must be bytes (0-255) got -1
 mp3> [256] | tobytes