Files
lneto/internal/ring_test.go
T
2025-01-14 07:55:22 -03:00

363 lines
9.3 KiB
Go

package internal
import (
"bytes"
"io"
"math/rand"
"testing"
)
func TestRing(t *testing.T) {
rng := rand.New(rand.NewSource(0))
const bufSize = 10
r := &Ring{
Buf: make([]byte, bufSize),
}
const data = "hello"
_, err := r.WriteString(data)
if err != nil {
t.Error(err)
}
// Case where data is contiguous and at start of buffer.
var buf [bufSize]byte
n, err := fragmentReadInto(r, buf[:])
if err != nil {
t.Fatal(err)
}
if string(buf[:n]) != data {
t.Fatalf("got %q; want %q", buf[:n], data)
}
// Case where data overwrites end of buffer.
const overdata = "hello world"
n, err = r.Write([]byte(overdata))
if err == nil || n > 0 {
t.Fatal(err, n)
}
// Set Random data in ring buffer and read it back.
for i := 0; i < 32; i++ {
n := rng.Intn(bufSize)
copy(buf[:], overdata[:n])
offset := rng.Intn(bufSize - 1)
setRingData(t, r, offset, buf[:n])
// Case where data wraps around end of buffer.
n, err = r.Read(buf[:])
if err != nil {
break
}
if string(buf[:n]) != overdata[:n] {
t.Error("got", buf[:n], "want", overdata[:n])
}
}
// Set random data and write some more and read it back.
for i := 0; i < 32; i++ {
nfirst := rng.Intn(bufSize) / 2
nsecond := rng.Intn(bufSize) / 2
if nfirst+nsecond > bufSize {
nfirst = bufSize - nsecond
}
offset := rng.Intn(bufSize - 1)
copy(buf[:], overdata[:nfirst])
setRingData(t, r, offset, buf[:nfirst])
// println("test", r.end, r.off, offset, r)
ngot, err := r.WriteString(overdata[nfirst : nfirst+nsecond])
if err != nil {
t.Fatal(err)
}
if ngot != nsecond {
t.Errorf("%d did not write data correctly: got %d; want %d", i, ngot, nsecond)
}
buf = [bufSize]byte{}
// Case where data wraps around end of buffer.
n, err = r.Read(buf[:])
if err != nil {
break
}
if n != nfirst+nsecond {
t.Errorf("got %d; want %d (%d+%d)", n, nfirst+nsecond, nfirst, nsecond)
}
if string(buf[:n]) != overdata[:n] {
t.Errorf("got %q; want %q", buf[:n], overdata[:n])
}
}
var readback [bufSize]byte
var zeros [bufSize]byte
// Set random data and write some more and read it back with ReadAt and ReadPeek and ReadDiscard.
for i := 0; i < 32; i++ {
nfirst := rng.Intn(len(data))/2 + 1 // write garbage data first.
nsecond := rng.Intn(len(data))/2 + 1
if nfirst+nsecond > bufSize {
nfirst = bufSize - nsecond
}
r.Reset()
randOff := rng.Intn(bufSize)
content := append([]byte{}, zeros[:nfirst]...)
content = append(content, data[:nsecond]...)
setRingData(t, r, randOff, content)
// Two-tap ReadPeek to make sure pointer not advanced.
for i := 0; i < 2; i++ {
n, err = r.ReadPeek(readback[:])
if err != nil && err != io.EOF {
t.Fatal("read failed", err)
} else if n != nfirst+nsecond {
t.Errorf("want!=got bytes read %d, %d", nfirst+nsecond, n)
} else if !bytes.Equal(readback[:nfirst], zeros[:nfirst]) {
t.Error("first section not match")
} else if !bytes.Equal(readback[nfirst:nfirst+nsecond], []byte(data[:nsecond])) {
t.Error("second section not match")
}
}
// Two-tap ReadAt to make sure pointer not advanced.
for i := 0; i < 2; i++ {
off := rng.Intn(nfirst + nsecond)
n, err = r.ReadAt(readback[:nfirst+nsecond-off], int64(off))
readat := readback[:n]
first := zeros[min(off, nfirst):nfirst]
secondOff := max(0, off-nfirst)
second := []byte(data[secondOff:nsecond])
gotSecond := readat[len(first):]
if err != nil && err != io.EOF {
t.Fatal("read failed", off, err)
} else if n != nfirst+nsecond-off {
t.Errorf("want!=got bytes read %d, %d", nfirst+nsecond-off, n)
} else if len(first) > 0 && !bytes.Equal(readat[:nfirst-off], first) {
t.Error("first section not match")
} else if len(second) > 0 && !bytes.Equal(gotSecond, second) {
t.Errorf("second section not match got=%q want=%q", gotSecond, second)
}
}
// ReadDiscard test.
discard := rng.Intn(nfirst+nsecond) + 1
r.ReadDiscard(discard)
n, err := r.Read(readback[:])
if err != nil && err != io.EOF {
t.Fatal(err)
}
wantN := nfirst + nsecond - discard
if wantN != n {
t.Errorf("Want %d bytes read, got %d", wantN, n)
}
if !bytes.Equal(readback[:n], content[discard:]) {
t.Errorf("want data read %q, got %q", content[discard:], readback[:n])
}
}
_ = r._string(0)
}
func TestRing2(t *testing.T) {
const maxsize = 6
const ntests = 80000
rng := rand.New(rand.NewSource(0))
data := make([]byte, maxsize)
ringbuf := make([]byte, maxsize)
auxbuf := make([]byte, maxsize)
rng.Read(data)
for i := 0; i < ntests; i++ {
dsize := max(rng.Intn(len(data)), 1)
if !testRing1_loopback(t, rng, ringbuf, data[:dsize], auxbuf) {
t.Fatalf("failed test %d", i)
}
}
}
func TestRingWriteLimited(t *testing.T) {
rng := rand.New(rand.NewSource(2))
const bufSize = 8
r := &Ring{
Buf: make([]byte, bufSize),
}
var data [bufSize]byte
var wdata [bufSize]byte
for i := 0; i < 10000; i++ {
for i := range r.Buf {
r.Buf[i] = 0
}
buffered, _ := rng.Read(data[:rng.Intn(bufSize-2)+1])
off := rng.Intn(bufSize)
setRingData(t, r, off, data[:buffered])
if r.Buffered() != buffered {
t.Fatalf("failed to set buffered amount of data")
} else if r.Off != off {
t.Fatal("bad offset")
}
free := r.Free()
toWrite := rng.Intn(free-1) + 1
rng.Read(wdata[:toWrite])
limOff := rng.Intn(bufSize) + 1
var wantN int
isContiguous := limOff > r.End
if isContiguous {
wantN = min(toWrite, limOff-r.End)
} else {
wantN = min(toWrite, len(r.Buf)-r.End+limOff)
}
overwrite := toWrite > wantN
n, err := r.WriteLimited(wdata[:toWrite], limOff)
if !overwrite && err != nil {
t.Errorf("limited write: %s", err)
} else if !overwrite && n != wantN {
t.Errorf("nwant=%d ngot=%d off=%d lim=%d towrite=%d buffered=%d/%d wantremain=%d gotremain=%d endOff=%d", wantN, n, off, limOff, toWrite, buffered, r.Size(), free-wantN, free-n, r.Off)
} else if overwrite && (err == nil || n != 0) {
t.Errorf("expected full buffer error and no data written on limit overwrite, got %d", n)
}
for i := r.End % r.Size(); i != limOff && i != r.Off; i = (i + 1) % r.Size() {
if r.Buf[i] != 0 {
t.Fatalf("OVERWRITE pos=%d end=%d lim=%d", i, r.End, limOff)
}
}
}
}
func TestRing_findcrash(t *testing.T) {
const maxsize = 33
const ntests = 800000
r := Ring{
Buf: make([]byte, maxsize*6),
}
rng := rand.New(rand.NewSource(0))
data := make([]byte, maxsize)
for i := 0; i < ntests; i++ {
free := r.Free()
if free < 0 {
t.Fatal("free < 0")
}
if rng.Intn(2) == 0 {
l := max(rng.Intn(len(data)), 1)
if l > free {
continue // Buffer full.
}
n, err := r.Write(data[:l])
expectFree := free - n
free = r.Free()
if n != l {
t.Fatal(i, "write failed", n, l, err)
} else if expectFree != free {
t.Fatal(i, "free not updated correctly", expectFree, free)
}
}
buffered := r.Buffered()
if buffered < 0 {
t.Fatal("buffered < 0")
}
if rng.Intn(2) == 0 {
l := max(rng.Intn(len(data)), 1)
n, err := r.Read(data[:l])
expectRead := min(buffered, l)
expectBuffered := buffered - n
buffered = r.Buffered()
if n != expectRead {
t.Fatal(i, "read failed", n, l, expectRead, err)
} else if buffered != expectBuffered {
t.Fatal(i, "buffered not updated correctly", expectBuffered, buffered)
}
}
}
}
func testRing1_loopback(t *testing.T, rng *rand.Rand, ringbuf, data, auxbuf []byte) bool {
if len(data) > len(ringbuf) || len(data) > len(auxbuf) {
panic("invalid ringbuf or data")
}
dsize := len(data)
var r Ring
r.Buf = ringbuf
nfirst := rng.Intn(dsize) / 2
nsecond := rng.Intn(dsize) / 2
if nfirst == 0 || nsecond == 0 {
return true
}
offset := rng.Intn(dsize - 1)
setRingData(t, &r, offset, data[:nfirst])
ngot, err := r.Write(data[nfirst : nfirst+nsecond])
if err != nil {
t.Error(err)
return false
}
if ngot != nsecond {
t.Errorf("did not write data correctly: got %d; want %d", ngot, nsecond)
}
// Case where data wraps around end of buffer.
n, err := r.Read(auxbuf[:])
if err != nil {
t.Error(err)
return false
}
if n != nfirst+nsecond {
t.Errorf("got %d; want %d (%d+%d)", n, nfirst+nsecond, nfirst, nsecond)
}
if !bytes.Equal(auxbuf[:n], data[:n]) {
t.Errorf("got %q; want %q", auxbuf[:n], data[:n])
}
return !t.Failed()
}
func fragmentReadInto(r io.Reader, buf []byte) (n int, _ error) {
maxSize := len(buf) / 4
for {
ntop := min(n+rand.Intn(maxSize)+1, len(buf))
ngot, err := r.Read(buf[n:ntop])
n += ngot
if err != nil {
if err == io.EOF {
return n, nil
}
return n, err
}
if n == len(buf) {
return n, nil
}
}
}
func setRingData(t *testing.T, r *Ring, offset int, data []byte) {
t.Helper()
if len(data) > len(r.Buf) {
panic("data too large")
}
n := copy(r.Buf[offset:], data)
r.End = offset + n
if len(data)+offset > len(r.Buf) {
// End of buffer not enough to hold data, wrap around.
n = copy(r.Buf, data[n:])
r.End = n
}
r.Off = offset
r.onReadEnd()
// println("buf:", len(r.buf), "end:", r.end, "off:", r.off, offset, "data:", len(data))
free := r.Free()
wantFree := len(r.Buf) - len(data)
if free != wantFree {
t.Fatalf("free got %d; want %d", free, wantFree)
}
buffered := r.Buffered()
wantBuffered := len(data)
if buffered != wantBuffered {
t.Fatalf("buffered got %d; want %d", buffered, wantBuffered)
}
end := r.End
off := r.Off
sdata := r.string()
if sdata != string(data) {
t.Fatalf("data got %q; want %q", sdata, data)
}
r.End = end
r.Off = off
}