WIP: moved logic code in test tools to separate package for better code architecture

slicewriter/dummy_test.go

@@ -0,0 +1,56 @@
+package slicewriter
+
+/*
+   Copyright 2025 Suyono <suyono3484@gmail.com>
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+import (
+	"sync"
+	"testing"
+)
+
+func TestDummy(t *testing.T) {
+	var (
+		p    sync.Pool
+		a, b []byte
+	)
+
+	p = sync.Pool{
+		New: func() any {
+			return make([]byte, 4096)
+		},
+	}
+
+	a = p.Get().([]byte)
+	t.Logf("retrieve a from pool: len %d, cap %d", len(a), cap(a))
+
+	b = p.Get().([]byte)
+	t.Logf("retrieve b from pool: len %d, cap %d", len(b), cap(b))
+
+	a = a[:1024]
+	b = b[:1024]
+	t.Logf("resize a : len %d, cap %d", len(a), cap(a))
+	t.Logf("resize b : len %d, cap %d", len(b), cap(b))
+
+	p.Put(a[:cap(a)])
+	p.Put(b)
+
+	t.Log("after putting back")
+	a = p.Get().([]byte)
+	t.Logf("retrieve a from pool: len %d, cap %d", len(a), cap(a))
+
+	b = p.Get().([]byte)
+	t.Logf("retrieve b from pool: len %d, cap %d", len(b), cap(b))
+}

slicewriter/slicewriter.go

@@ -0,0 +1,52 @@
+package slicewriter
+
+/*
+   Copyright 2025 Suyono <suyono3484@gmail.com>
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+import "io"
+
+type SliceWriter struct {
+	off int
+	buf []byte
+}
+
+func (w *SliceWriter) Write(p []byte) (int, error) {
+	if len(p)+w.off <= len(w.buf) {
+		copy(w.buf[w.off:], p)
+		w.off += len(p)
+		return len(p), nil
+	}
+
+	space := len(w.buf) - w.off
+	copy(w.buf[:w.off], p[:space])
+	w.off += space
+	return space, io.ErrShortWrite
+}
+
+func (w *SliceWriter) Reset() {
+	w.off = 0
+}
+
+func (w *SliceWriter) Bytes() []byte {
+	return w.buf[:w.off]
+}
+
+func NewSliceWriter(b []byte) *SliceWriter {
+	return &SliceWriter{
+		off: 0,
+		buf: b,
+	}
+}