Files
pixa/internal/imageprocessor/deadline_internal_test.go
T
clawbot 3ba9ae9c39
check / check (push) Waiting to run
Stop a transcode whose request has ended before it encodes (closes #243)
Process looked at its context only while waiting for a processing
slot, so a transcode kept its slot and worked on after its request's
downstream_timeout. acquireSlot now gives the slot back when the
context has ended by the time it has one, and encode returns the
context's error without beginning. govips gives pixa no way to stop
libvips once an encode has begun, so that encode keeps its slot. A
request waiting on a shared transcode stopped at the first request's
deadline is answered 503, not 500. README.md "Routes" says both.

Model: opus-5-5
2026-10-15 18:44:11 +02:00

107 lines
2.8 KiB
Go

package imageprocessor
import (
"bytes"
"context"
"errors"
"io"
"testing"
"time"
)
// readerAfterDeadline is a Process input whose first Read waits until done
// is closed, so the deadline passes after Process has taken its slot and
// before it encodes.
type readerAfterDeadline struct {
data *bytes.Reader
done <-chan struct{}
waited bool
}
func (r *readerAfterDeadline) Read(p []byte) (int, error) {
if !r.waited {
r.waited = true
<-r.done
}
return r.data.Read(p)
}
// inputNotToBeRead is a Process input that fails the test when it is read.
type inputNotToBeRead struct {
t *testing.T
}
func (r inputNotToBeRead) Read([]byte) (int, error) {
r.t.Error("Process read its input although its deadline had passed")
return 0, io.EOF
}
// TestProcessStopsWhenDeadlinePassed checks that Process returns
// context.DeadlineExceeded, and holds no slot afterwards, when its context's
// deadline has passed before it starts, then without reading its input, or
// while it reads its input. govips gives pixa no way to stop libvips once an
// encode has begun, so Process must not begin one for a request that has
// ended.
func TestProcessStopsWhenDeadlinePassed(t *testing.T) {
t.Parallel()
input := createTestJPEG(t, 50, 50)
t.Run("before Process starts", func(t *testing.T) {
t.Parallel()
ctx, cancel := context.WithDeadline(t.Context(),
time.Now().Add(-time.Second))
defer cancel()
// With a slot free, the select in acquireSlot takes the slot or sees
// the ended context at random, so Process is called many times
for range 100 {
checkProcessStopsAtDeadline(ctx, t, inputNotToBeRead{t: t})
}
})
t.Run("while Process reads its input", func(t *testing.T) {
t.Parallel()
ctx, cancel := context.WithTimeout(t.Context(), 100*time.Millisecond)
defer cancel()
checkProcessStopsAtDeadline(ctx, t, &readerAfterDeadline{
data: bytes.NewReader(input), done: ctx.Done(),
})
})
}
// checkProcessStopsAtDeadline runs Process on input with ctx, whose deadline
// has passed by the time Process could encode, and fails the test unless
// Process returns context.DeadlineExceeded and gives its slot back.
func checkProcessStopsAtDeadline(
ctx context.Context, t *testing.T, input io.Reader,
) {
t.Helper()
proc := New(Params{MaxConcurrentProcessing: 1})
result, err := proc.Process(ctx, input, smallJPEGRequest())
if result != nil {
t.Logf("Process() made a %dx%d image after its deadline passed",
result.Width, result.Height)
_ = result.Content.Close()
}
t.Logf("Process() error = %v", err)
if !errors.Is(err, context.DeadlineExceeded) {
t.Errorf("Process() error = %v, want context.DeadlineExceeded", err)
}
if held := len(proc.processingSemaphore); held != 0 {
t.Errorf("%d slots still held after Process() returned", held)
}
}