func TestSeekAndRead(t *testing.T) {
dserv := testu.GetDAGServ()
inbuf := make([]byte, 256)
for i := 0; i <= 255; i++ {
inbuf[i] = byte(i)
}
node := testu.GetNode(t, dserv, inbuf)
ctx, closer := context.WithCancel(context.Background())
defer closer()
reader, err := NewDagReader(ctx, node, dserv)
if err != nil {
t.Fatal(err)
}
for i := 255; i >= 0; i-- {
reader.Seek(int64(i), os.SEEK_SET)
if reader.Offset() != int64(i) {
t.Fatal("expected offset to be increased by one after read")
}
out := readByte(t, reader)
if int(out) != i {
t.Fatalf("read %d at index %d, expected %d", out, i, i)
}
if reader.Offset() != int64(i+1) {
t.Fatal("expected offset to be increased by one after read")
}
}
}
func TestRelativeSeek(t *testing.T) {
dserv := testu.GetDAGServ()
ctx, closer := context.WithCancel(context.Background())
defer closer()
inbuf := make([]byte, 1024)
for i := 0; i < 256; i++ {
inbuf[i*4] = byte(i)
}
inbuf[1023] = 1 // force the reader to be 1024 bytes
node := testu.GetNode(t, dserv, inbuf)
reader, err := NewDagReader(ctx, node, dserv)
if err != nil {
t.Fatal(err)
}
for i := 0; i < 256; i++ {
if reader.Offset() != int64(i*4) {
t.Fatalf("offset should be %d, was %d", i*4, reader.Offset())
}
out := readByte(t, reader)
if int(out) != i {
t.Fatalf("expected to read: %d at %d, read %d", i, reader.Offset()-1, out)
}
if i != 255 {
_, err := reader.Seek(3, os.SEEK_CUR)
if err != nil {
t.Fatal(err)
}
}
}
_, err = reader.Seek(4, os.SEEK_END)
if err != nil {
t.Fatal(err)
}
for i := 0; i < 256; i++ {
if reader.Offset() != int64(1020-i*4) {
t.Fatalf("offset should be %d, was %d", 1020-i*4, reader.Offset())
}
out := readByte(t, reader)
if int(out) != 255-i {
t.Fatalf("expected to read: %d at %d, read %d", 255-i, reader.Offset()-1, out)
}
reader.Seek(-5, os.SEEK_CUR) // seek 4 bytes but we read one byte every time so 5 bytes
}
}