init

pkg/util/binary/binary.go

@@ -0,0 +1,140 @@
+// Copyright (C) 2025 wangyusong
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+package binary
+
+import (
+	"encoding/binary"
+	"io"
+	"math"
+	"sync"
+
+	"github.com/pkg/errors"
+
+	"github.com/glidea/zenfeed/pkg/util/buffer"
+)
+
+// WriteString writes a string to a writer.
+func WriteString(w io.Writer, str string) error {
+	len := len(str)
+	if len > math.MaxUint32 {
+		return errors.New("length exceeds maximum uint32")
+	}
+
+	if err := WriteUint32(w, uint32(len)); err != nil {
+		return errors.Wrap(err, "write length")
+	}
+	if _, err := io.WriteString(w, str); err != nil {
+		return errors.Wrap(err, "write data")
+	}
+
+	return nil
+}
+
+// ReadString reads a string from a reader.
+func ReadString(r io.Reader) (string, error) {
+	len, err := ReadUint32(r)
+	if err != nil {
+		return "", errors.Wrap(err, "read length")
+	}
+
+	bb := buffer.Get()
+	defer buffer.Put(bb)
+	// bb.EnsureRemaining(int(len))
+
+	if _, err := io.CopyN(bb, r, int64(len)); err != nil {
+		return "", errors.Wrap(err, "read data")
+	}
+
+	return bb.String(), nil
+}
+
+var smallBufPool = sync.Pool{
+	New: func() any {
+		// 8 bytes is enough for uint64, uint32, float32.
+		b := make([]byte, 8)
+
+		return &b
+	},
+}
+
+// WriteUint64 writes a uint64 using a pooled buffer.
+func WriteUint64(w io.Writer, v uint64) error {
+	bp := smallBufPool.Get().(*[]byte)
+	defer smallBufPool.Put(bp)
+	b := *bp
+
+	binary.LittleEndian.PutUint64(b, v)
+	_, err := w.Write(b[:8])
+
+	return err
+}
+
+// ReadUint64 reads a uint64 using a pooled buffer.
+func ReadUint64(r io.Reader) (uint64, error) {
+	bp := smallBufPool.Get().(*[]byte)
+	defer smallBufPool.Put(bp)
+	b := (*bp)[:8]
+
+	// Read exactly 8 bytes into the slice.
+	if _, err := io.ReadFull(r, b); err != nil {
+		return 0, errors.Wrap(err, "read uint64")
+	}
+
+	return binary.LittleEndian.Uint64(b), nil
+}
+
+// WriteUint32 writes a uint32 using a pooled buffer.
+func WriteUint32(w io.Writer, v uint32) error {
+	bp := smallBufPool.Get().(*[]byte)
+	defer smallBufPool.Put(bp)
+	b := *bp
+
+	binary.LittleEndian.PutUint32(b, v)
+	_, err := w.Write(b[:4])
+
+	return err
+}
+
+// ReadUint32 reads a uint32 using a pooled buffer.
+func ReadUint32(r io.Reader) (uint32, error) {
+	bp := smallBufPool.Get().(*[]byte)
+	defer smallBufPool.Put(bp)
+	b := (*bp)[:4]
+
+	// Read exactly 4 bytes into the slice.
+	if _, err := io.ReadFull(r, b); err != nil {
+		return 0, errors.Wrap(err, "read uint32")
+	}
+
+	return binary.LittleEndian.Uint32(b), nil
+}
+
+// WriteFloat32 writes a float32 using a pooled buffer.
+func WriteFloat32(w io.Writer, v float32) error {
+	return WriteUint32(w, math.Float32bits(v))
+}
+
+// ReadFloat32 reads a float32 using a pooled buffer.
+func ReadFloat32(r io.Reader) (float32, error) {
+	// Read the uint32 bits first.
+	bits, err := ReadUint32(r)
+	if err != nil {
+		return 0, err
+	}
+
+	// Convert bits to float32.
+	return math.Float32frombits(bits), nil
+}

pkg/util/binary/binary_test.go

@@ -0,0 +1,72 @@
+// Copyright (C) 2025 wangyusong
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+package binary
+
+import (
+	"bytes"
+	"testing"
+
+	. "github.com/onsi/gomega"
+
+	"github.com/glidea/zenfeed/pkg/test"
+)
+
+func TestWriteString(t *testing.T) {
+	RegisterTestingT(t)
+
+	type givenDetail struct{}
+	type whenDetail struct {
+		str string
+	}
+	type thenExpected struct{}
+
+	tests := []test.Case[givenDetail, whenDetail, thenExpected]{
+		{
+			Scenario: "Write empty string",
+			When:     "writing an empty string to a buffer",
+			Then:     "should write successfully without error",
+			WhenDetail: whenDetail{
+				str: "",
+			},
+			ThenExpected: thenExpected{},
+		},
+		{
+			Scenario: "Write normal string",
+			When:     "writing a normal string to a buffer",
+			Then:     "should write successfully without error",
+			WhenDetail: whenDetail{
+				str: "hello world",
+			},
+			ThenExpected: thenExpected{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.Scenario, func(t *testing.T) {
+			// When.
+			buf := &bytes.Buffer{}
+			err := WriteString(buf, tt.WhenDetail.str)
+
+			// Then.
+			Expect(err).NotTo(HaveOccurred())
+
+			// Verify the written data by reading it back
+			readStr, readErr := ReadString(bytes.NewReader(buf.Bytes()))
+			Expect(readErr).NotTo(HaveOccurred())
+			Expect(readStr).To(Equal(tt.WhenDetail.str))
+		})
+	}
+}