feat(landscape): window executor Compute with worker pool and grid checks

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/landscape/fakeio_test.go

@@ -0,0 +1,75 @@
+package landscape
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"gis/internal/raster"
+)
+
+// fakeIO keeps rasters in memory keyed by path.
+type fakeIO struct {
+	mu    sync.Mutex
+	files map[string]*fakeRaster
+}
+
+type fakeRaster struct {
+	grid raster.Grid
+	data []float64 // row-major
+}
+
+func newFakeIO() *fakeIO { return &fakeIO{files: map[string]*fakeRaster{}} }
+
+func (f *fakeIO) put(path string, g raster.Grid, data []float64) {
+	f.files[path] = &fakeRaster{grid: g, data: data}
+}
+
+type fakeReader struct{ r *fakeRaster }
+
+func (r *fakeReader) Grid() raster.Grid       { return r.r.grid }
+func (r *fakeReader) NoData() (float64, bool) { return -9999, true }
+func (r *fakeReader) Close() error            { return nil }
+func (r *fakeReader) ReadFloat64(w raster.Window, dst []float64) error {
+	for y := 0; y < w.Height; y++ {
+		copy(dst[y*w.Width:(y+1)*w.Width], r.r.data[(w.Y+y)*r.r.grid.Width+w.X:(w.Y+y)*r.r.grid.Width+w.X+w.Width])
+	}
+	return nil
+}
+
+type fakeWriter struct {
+	f *fakeIO
+	r *fakeRaster
+}
+
+func (w *fakeWriter) WriteInt16(win raster.Window, src []int16) error {
+	w.f.mu.Lock()
+	defer w.f.mu.Unlock()
+	for y := 0; y < win.Height; y++ {
+		for x := 0; x < win.Width; x++ {
+			w.r.data[(win.Y+y)*w.r.grid.Width+win.X+x] = float64(src[y*win.Width+x])
+		}
+	}
+	return nil
+}
+func (w *fakeWriter) Close() error { return nil }
+
+func (f *fakeIO) Open(_ context.Context, path string) (raster.Reader, error) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	r, ok := f.files[path]
+	if !ok {
+		return nil, fmt.Errorf("fake: %s not found", path)
+	}
+	return &fakeReader{r: r}, nil
+}
+
+func (f *fakeIO) Create(_ context.Context, path string, g raster.Grid, _ raster.WriterOptions) (raster.Writer, error) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	r := &fakeRaster{grid: g, data: make([]float64, g.Width*g.Height)}
+	f.files[path] = r
+	return &fakeWriter{f: f, r: r}, nil
+}
+
+func (f *fakeIO) SameGrid(a, b raster.Grid) bool { return a == b }