init

vendor/github.com/anacrolix/torrent/mmap_span/mmap_span.go

@@ -0,0 +1,82 @@
+package mmap_span
+
+import (
+	"io"
+	"log"
+	"sync"
+
+	"github.com/edsrzf/mmap-go"
+)
+
+type segment struct {
+	*mmap.MMap
+}
+
+func (s segment) Size() int64 {
+	return int64(len(*s.MMap))
+}
+
+type MMapSpan struct {
+	mu sync.RWMutex
+	span
+}
+
+func (ms *MMapSpan) Append(mmap mmap.MMap) {
+	ms.span = append(ms.span, segment{&mmap})
+}
+
+func (ms *MMapSpan) Close() error {
+	ms.mu.Lock()
+	defer ms.mu.Unlock()
+	for _, mMap := range ms.span {
+		err := mMap.(segment).Unmap()
+		if err != nil {
+			log.Print(err)
+		}
+	}
+	return nil
+}
+
+func (ms *MMapSpan) Size() (ret int64) {
+	ms.mu.RLock()
+	defer ms.mu.RUnlock()
+	for _, seg := range ms.span {
+		ret += seg.Size()
+	}
+	return
+}
+
+func (ms *MMapSpan) ReadAt(p []byte, off int64) (n int, err error) {
+	ms.mu.RLock()
+	defer ms.mu.RUnlock()
+	ms.ApplyTo(off, func(intervalOffset int64, interval sizer) (stop bool) {
+		_n := copy(p, (*interval.(segment).MMap)[intervalOffset:])
+		p = p[_n:]
+		n += _n
+		return len(p) == 0
+	})
+	if len(p) != 0 {
+		err = io.EOF
+	}
+	return
+}
+
+func (ms *MMapSpan) WriteAt(p []byte, off int64) (n int, err error) {
+	ms.mu.RLock()
+	defer ms.mu.RUnlock()
+	ms.ApplyTo(off, func(iOff int64, i sizer) (stop bool) {
+		mMap := i.(segment)
+		_n := copy((*mMap.MMap)[iOff:], p)
+		// err = mMap.Sync(gommap.MS_ASYNC)
+		// if err != nil {
+		// 	return true
+		// }
+		p = p[_n:]
+		n += _n
+		return len(p) == 0
+	})
+	if err != nil && len(p) != 0 {
+		err = io.ErrShortWrite
+	}
+	return
+}

vendor/github.com/anacrolix/torrent/mmap_span/span.go

@@ -0,0 +1,21 @@
+package mmap_span
+
+type sizer interface {
+	Size() int64
+}
+
+type span []sizer
+
+func (s span) ApplyTo(off int64, f func(int64, sizer) (stop bool)) {
+	for _, interval := range s {
+		iSize := interval.Size()
+		if off >= iSize {
+			off -= iSize
+		} else {
+			if f(off, interval) {
+				return
+			}
+			off = 0
+		}
+	}
+}