flatex: Restructure a little

1 files changed, 38 insertions, 0 deletions

diff --git a/internal/flatex/decompress.go b/internal/flatex/decompress.go
new file mode 100644
index 00000000..641b6e7a
--- /dev/null
+++ b/internal/flatex/decompress.go
@@ -0,0 +1,38 @@
+package flatex
+
+import (
+	"io"
+
+	"git.sr.ht/~runxiyu/furgit/internal/bufpool"
+)
+
+func DecompressSized(src []byte, sizeHint int) (bufpool.Buffer, int, error) {
+	d := sliceInflaterPool.Get().(*sliceInflater)
+	defer sliceInflaterPool.Put(d)
+
+	if err := d.reset(src); err != nil {
+		return bufpool.Buffer{}, 0, err
+	}
+
+	out := bufpool.Borrow(sizeHint)
+	out.Resize(0)
+
+	for {
+		if len(d.toRead) > 0 {
+			out.Append(d.toRead)
+			d.toRead = nil
+			continue
+		}
+		if d.err != nil {
+			if d.err == io.EOF {
+				return out, d.pos, nil
+			}
+			out.Release()
+			return bufpool.Buffer{}, 0, d.err
+		}
+		d.step(d)
+		if d.err != nil && len(d.toRead) == 0 {
+			d.toRead = d.window.readFlush()
+		}
+	}
+}