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