ring_buffer_test.go

package ringbuffer

import (
	"bytes"
	"io"
	"strings"
	"testing"
)

func TestRingBuffer_interface(t *testing.T) {
	rb := New(1)
	var _ io.Writer = rb
	var _ io.Reader = rb
	// var _ io.StringWriter = rb
	var _ io.ByteReader = rb
	var _ io.ByteWriter = rb
}

func TestRingBuffer_Write(t *testing.T) {
	rb := New(64)

	// check empty or full
	if !rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is true but got false")
	}
	if rb.IsFull() {
		t.Fatalf("expect IsFull is false but got true")
	}
	if rb.Length() != 0 {
		t.Fatalf("expect len 0 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 64 {
		t.Fatalf("expect free 64 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}

	// write 4 * 4 = 16 bytes
	n, err := rb.Write([]byte(strings.Repeat("abcd", 4)))
	if err != nil {
		t.Fatalf("write failed: %v", err)
	}
	if n != 16 {
		t.Fatalf("expect write 16 bytes but got %d", n)
	}
	if rb.Length() != 16 {
		t.Fatalf("expect len 16 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 48 {
		t.Fatalf("expect free 48 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if bytes.Compare(rb.Bytes(), []byte(strings.Repeat("abcd", 4))) != 0 {
		t.Fatalf("expect 4 abcd but got %s. r.w=%d, r.r=%d", rb.Bytes(), rb.w, rb.r)
	}

	// check empty or full
	if rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is false but got true")
	}
	if rb.IsFull() {
		t.Fatalf("expect IsFull is false but got true")
	}

	// write 48 bytes, should full
	n, err = rb.Write([]byte(strings.Repeat("abcd", 12)))
	if err != nil {
		t.Fatalf("write failed: %v", err)
	}
	if n != 48 {
		t.Fatalf("expect write 48 bytes but got %d", n)
	}
	if rb.Length() != 64 {
		t.Fatalf("expect len 64 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 0 {
		t.Fatalf("expect free 0 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if rb.w != 0 {
		t.Fatalf("expect r.w=0 but got %d. r.r=%d", rb.w, rb.r)
	}
	if bytes.Compare(rb.Bytes(), []byte(strings.Repeat("abcd", 16))) != 0 {
		t.Fatalf("expect 16 abcd but got %s. r.w=%d, r.r=%d", rb.Bytes(), rb.w, rb.r)
	}

	// check empty or full
	if rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is false but got true")
	}
	if !rb.IsFull() {
		t.Fatalf("expect IsFull is true but got false")
	}

	// write more 4 bytes, should reject
	n, err = rb.Write([]byte(strings.Repeat("abcd", 1)))
	if err == nil {
		t.Fatalf("expect an error but got nil. n=%d, r.w=%d, r.r=%d", n, rb.w, rb.r)
	}
	if err != ErrIsFull {
		t.Fatalf("expect ErrIsFull but got nil")
	}
	if n != 0 {
		t.Fatalf("expect write 0 bytes but got %d", n)
	}
	if rb.Length() != 64 {
		t.Fatalf("expect len 64 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 0 {
		t.Fatalf("expect free 0 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}

	// check empty or full
	if rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is false but got true")
	}
	if !rb.IsFull() {
		t.Fatalf("expect IsFull is true but got false")
	}

	// reset this ringbuffer and set a long slice
	rb.Reset()
	n, err = rb.Write([]byte(strings.Repeat("abcd", 20)))
	if err == nil {
		t.Fatalf("expect ErrTooManyDataToWrite but got nil")
	}
	if n != 64 {
		t.Fatalf("expect write 64 bytes but got %d", n)
	}
	if rb.Length() != 64 {
		t.Fatalf("expect len 64 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 0 {
		t.Fatalf("expect free 0 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if rb.w != 0 {
		t.Fatalf("expect r.w=0 but got %d. r.r=%d", rb.w, rb.r)
	}

	// check empty or full
	if rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is false but got true")
	}
	if !rb.IsFull() {
		t.Fatalf("expect IsFull is true but got false")
	}

	if bytes.Compare(rb.Bytes(), []byte(strings.Repeat("abcd", 16))) != 0 {
		t.Fatalf("expect 16 abcd but got %s. r.w=%d, r.r=%d", rb.Bytes(), rb.w, rb.r)
	}

	rb.Reset()
	// write 4 * 2 = 8 bytes
	n, err = rb.Write([]byte(strings.Repeat("abcd", 2)))
	if err != nil {
		t.Fatalf("write failed: %v", err)
	}
	if n != 8 {
		t.Fatalf("expect write 16 bytes but got %d", n)
	}
	if rb.Length() != 8 {
		t.Fatalf("expect len 16 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 56 {
		t.Fatalf("expect free 48 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	buf := make([]byte, 5)
	rb.Read(buf)
	if rb.Length() != 3 {
		t.Fatalf("expect len 3 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	_, err = rb.Write([]byte(strings.Repeat("abcd", 15)))

	if bytes.Compare(rb.Bytes(), []byte("bcd"+strings.Repeat("abcd", 15))) != 0 {
		t.Fatalf("expect 63 ... but got %s. r.w=%d, r.r=%d", rb.Bytes(), rb.w, rb.r)
	}

	rb.Reset()
	n, err = rb.Write([]byte(strings.Repeat("abcd", 16)))
	if err != nil {
		t.Fatalf("write failed: %v", err)
	}
	if n != 64 {
		t.Fatalf("expect write 64 bytes but got %d", n)
	}
	if rb.Free() != 0 {
		t.Fatalf("expect free 0 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	buf = make([]byte, 16)
	rb.Read(buf)
	n, err = rb.Write([]byte(strings.Repeat("1234", 4)))
	if err != nil {
		t.Fatalf("write failed: %v", err)
	}
	if n != 16 {
		t.Fatalf("expect write 16 bytes but got %d", n)
	}
	if rb.Free() != 0 {
		t.Fatalf("expect free 0 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if !bytes.Equal(append(buf, rb.Bytes()...), []byte(strings.Repeat("abcd", 16)+strings.Repeat("1234", 4))) {
		t.Fatalf("expect 16 abcd and 4 1234 but got %s. r.w=%d, r.r=%d", rb.Bytes(), rb.w, rb.r)
	}
}

func TestRingBuffer_Read(t *testing.T) {
	rb := New(64)

	// check empty or full
	if !rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is true but got false")
	}
	if rb.IsFull() {
		t.Fatalf("expect IsFull is false but got true")
	}
	if rb.Length() != 0 {
		t.Fatalf("expect len 0 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 64 {
		t.Fatalf("expect free 64 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}

	// read empty
	buf := make([]byte, 1024)
	n, err := rb.Read(buf)
	if err == nil {
		t.Fatalf("expect an error but got nil")
	}
	if err != ErrIsEmpty {
		t.Fatalf("expect ErrIsEmpty but got nil")
	}
	if n != 0 {
		t.Fatalf("expect read 0 bytes but got %d", n)
	}
	if rb.Length() != 0 {
		t.Fatalf("expect len 0 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 64 {
		t.Fatalf("expect free 64 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if rb.r != 0 {
		t.Fatalf("expect r.r=0 but got %d. r.w=%d", rb.r, rb.w)
	}

	// write 16 bytes to read
	rb.Write([]byte(strings.Repeat("abcd", 4)))
	n, err = rb.Read(buf)
	if err != nil {
		t.Fatalf("read failed: %v", err)
	}
	if n != 16 {
		t.Fatalf("expect read 16 bytes but got %d", n)
	}
	if rb.Length() != 0 {
		t.Fatalf("expect len 0 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 64 {
		t.Fatalf("expect free 64 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if rb.r != 16 {
		t.Fatalf("expect r.r=16 but got %d. r.w=%d", rb.r, rb.w)
	}

	// write long slice to  read
	rb.Write([]byte(strings.Repeat("abcd", 20)))
	n, err = rb.Read(buf)
	if err != nil {
		t.Fatalf("read failed: %v", err)
	}
	if n != 64 {
		t.Fatalf("expect read 64 bytes but got %d", n)
	}
	if rb.Length() != 0 {
		t.Fatalf("expect len 0 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 64 {
		t.Fatalf("expect free 64 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if rb.r != 16 {
		t.Fatalf("expect r.r=16 but got %d. r.w=%d", rb.r, rb.w)
	}

}

func TestRingBuffer_ByteInterface(t *testing.T) {
	rb := New(2)

	// write one
	err := rb.WriteByte('a')
	if err != nil {
		t.Fatalf("WriteByte failed: %v", err)
	}
	if rb.Length() != 1 {
		t.Fatalf("expect len 1 byte but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 1 {
		t.Fatalf("expect free 1 byte but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if bytes.Compare(rb.Bytes(), []byte{'a'}) != 0 {
		t.Fatalf("expect a but got %s. r.w=%d, r.r=%d", rb.Bytes(), rb.w, rb.r)
	}
	// check empty or full
	if rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is false but got true")
	}
	if rb.IsFull() {
		t.Fatalf("expect IsFull is false but got true")
	}

	// write to, isFull
	err = rb.WriteByte('b')
	if err != nil {
		t.Fatalf("WriteByte failed: %v", err)
	}
	if rb.Length() != 2 {
		t.Fatalf("expect len 2 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 0 {
		t.Fatalf("expect free 0 byte but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if bytes.Compare(rb.Bytes(), []byte{'a', 'b'}) != 0 {
		t.Fatalf("expect a but got %s. r.w=%d, r.r=%d", rb.Bytes(), rb.w, rb.r)
	}
	// check empty or full
	if rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is false but got true")
	}
	if !rb.IsFull() {
		t.Fatalf("expect IsFull is true but got false")
	}

	// write
	err = rb.WriteByte('c')
	if err == nil {
		t.Fatalf("expect ErrIsFull but got nil")
	}
	if rb.Length() != 2 {
		t.Fatalf("expect len 2 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 0 {
		t.Fatalf("expect free 0 byte but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if bytes.Compare(rb.Bytes(), []byte{'a', 'b'}) != 0 {
		t.Fatalf("expect a but got %s. r.w=%d, r.r=%d", rb.Bytes(), rb.w, rb.r)
	}
	// check empty or full
	if rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is false but got true")
	}
	if !rb.IsFull() {
		t.Fatalf("expect IsFull is true but got false")
	}

	// read one
	b, err := rb.ReadByte()
	if err != nil {
		t.Fatalf("ReadByte failed: %v", err)
	}
	if b != 'a' {
		t.Fatalf("expect a but got %c. r.w=%d, r.r=%d", b, rb.w, rb.r)
	}
	if rb.Length() != 1 {
		t.Fatalf("expect len 1 byte but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 1 {
		t.Fatalf("expect free 1 byte but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	if bytes.Compare(rb.Bytes(), []byte{'b'}) != 0 {
		t.Fatalf("expect a but got %s. r.w=%d, r.r=%d", rb.Bytes(), rb.w, rb.r)
	}
	// check empty or full
	if rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is false but got true")
	}
	if rb.IsFull() {
		t.Fatalf("expect IsFull is false but got true")
	}

	// read two, empty
	b, err = rb.ReadByte()
	if err != nil {
		t.Fatalf("ReadByte failed: %v", err)
	}
	if b != 'b' {
		t.Fatalf("expect b but got %c. r.w=%d, r.r=%d", b, rb.w, rb.r)
	}
	if rb.Length() != 0 {
		t.Fatalf("expect len 0 byte but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 2 {
		t.Fatalf("expect free 2 byte but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	// check empty or full
	if !rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is true but got false")
	}
	if rb.IsFull() {
		t.Fatalf("expect IsFull is false but got true")
	}

	// read three, error
	b, err = rb.ReadByte()
	if err == nil {
		t.Fatalf("expect ErrIsEmpty but got nil")
	}
	if rb.Length() != 0 {
		t.Fatalf("expect len 0 byte but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 2 {
		t.Fatalf("expect free 2 byte but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)
	}
	// check empty or full
	if !rb.IsEmpty() {
		t.Fatalf("expect IsEmpty is true but got false")
	}
	if rb.IsFull() {
		t.Fatalf("expect IsFull is false but got true")
	}
}