"syscall"
	"testing"
)

// This test creates a set of FIFOs and writes to them in reverse order. It
// checks that the output order matches the write order. The test binary opens
// the FIFOs in their original order and spawns a goroutine for each that reads
// from the FIFO and writes the result to stderr. If I/O was blocking, all
// goroutines would be blocked waiting for one read call to return, and the
// output order wouldn't match.

		t.Fatal(err)
	}
	if _, err := c.Get(id); err != nil {
		t.Fatal(err)
	}
	c.OutputFile(entry.OutputID)
	mtime3 := now
	if _, err := c.Get(dummyID(2)); err == nil { // haven't done a Get for this since original write above
		t.Fatalf("Trim did not remove dummyID(2)")
	}

	// The c.Get(id) refreshed id's mtime again.
	// Check that another 5 days later it is still not gone,

	z := NewWriter(buf)
	msg := []byte("hello world")
	z.Write(msg)
	z.Close()
	z.Reset(buf2)
	z.Write(msg)
	z.Close()
	if buf.String() != buf2.String() {
		t.Errorf("buf2 %q != original buf of %q", buf2.String(), buf.String())
	}
}

type limitedWriter struct {
	N int
}

func (l *limitedWriter) Write(p []byte) (n int, err error) {
	if n := l.N; n < len(p) {
		l.N = 0

		after[p.ID] = []*Block{b}
		for {
			nextIdx := idToIdx[b.ID] + 1
			if nextIdx >= len(f.Blocks) { // reached end of function (maybe impossible?)
				break
			}
			nextb := f.Blocks[nextIdx]
			if nextb == p { // original loop predecessor is next
				break
			}
			if loopnest.b2l[nextb.ID] == loop {
				after[p.ID] = append(after[p.ID], nextb)
			}
			b = nextb
		}

	// underlying file descriptor with reference counting.
	RefCountPtr *int32

	// RefCount is the reference count of Sysfd. When a copy of an FD is made,
	// it points to the reference count of the original FD instance.
	RefCount int32

	// Cache for the file type, lazily initialized when Seek is called.
	Filetype uint32

	// If the file represents a directory, this field contains the current

// source position information (e.g. file and line). Note that we don't
// include function name as part of the sorting criteria, the thinking
// being that is better to provide things in the original source order.
func (p *pstate) sortUnits(units []extcu) {
	slices.SortFunc(units, func(ui, uj extcu) int {
		ifile := p.funcs[ui.fnfid].file
		jfile := p.funcs[uj.fnfid].file

		t.Fatalf("Indent error: %v", err)
	}
	b1 := buf1.Bytes()
	if !bytes.Equal(b1, b) {
		t.Error("Indent(Indent(jsonBig)) != Indent(jsonBig):")
		diff(t, b1, b)
		return
	}

	// should get back to original
	buf1.Reset()
	if err := Compact(&buf1, b); err != nil {
		t.Fatalf("Compact error: %v", err)
	}
	b1 = buf1.Bytes()
	if !bytes.Equal(b1, jsonBig) {
		t.Error("Compact(Indent(jsonBig)) != jsonBig:")

func SortFunc[S ~[]E, E any](x S, cmp func(a, b E) int) {
	n := len(x)
	pdqsortCmpFunc(x, 0, n, bits.Len(uint(n)), cmp)
}

// SortStableFunc sorts the slice x while keeping the original order of equal
// elements, using cmp to compare elements in the same way as [SortFunc].
func SortStableFunc[S ~[]E, E any](x S, cmp func(a, b E) int) {
	stableCmpFunc(x, len(x), cmp)
}

	z := new(Reader)
	if err := z.Reset(r); err != nil {
		return nil, err
	}
	return z, nil
}

// Reset discards the [Reader] z's state and makes it equivalent to the
// result of its original state from [NewReader], but reading from r instead.
// This permits reusing a [Reader] rather than allocating a new one.
func (z *Reader) Reset(r io.Reader) error {
	*z = Reader{
		decompressor: z.decompressor,

// tryLimitedReader tries to assert the io.Reader to io.LimitedReader, it returns the io.LimitedReader,
// the underlying io.Reader and the remaining amount of bytes if the assertion succeeds,
// otherwise it just returns the original io.Reader and the theoretical unlimited remaining amount of bytes.
func tryLimitedReader(r io.Reader) (*io.LimitedReader, io.Reader, int64) {
	var remain int64 = 1<<63 - 1 // by default, copy until EOF