mirror of
https://github.com/chrislusf/seaweedfs
synced 2024-05-20 02:10:20 +02:00
61 lines
1.3 KiB
Go
61 lines
1.3 KiB
Go
package memory_map
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import (
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"os"
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"time"
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"github.com/chrislusf/seaweedfs/weed/storage/backend"
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)
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var (
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_ backend.DataStorageBackend = &MemoryMappedFile{}
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)
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type MemoryMappedFile struct {
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mm *MemoryMap
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}
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func NewMemoryMappedFile(f *os.File, memoryMapSizeMB uint32) *MemoryMappedFile {
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mmf := &MemoryMappedFile{
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mm: new(MemoryMap),
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}
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mmf.mm.CreateMemoryMap(f, 1024*1024*uint64(memoryMapSizeMB))
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return mmf
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}
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func (mmf *MemoryMappedFile) ReadAt(p []byte, off int64) (n int, err error) {
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readBytes, e := mmf.mm.ReadMemory(uint64(off), uint64(len(p)))
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if e != nil {
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return 0, e
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}
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// TODO avoid the extra copy
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copy(p, readBytes)
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return len(readBytes), nil
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}
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func (mmf *MemoryMappedFile) WriteAt(p []byte, off int64) (n int, err error) {
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mmf.mm.WriteMemory(uint64(off), uint64(len(p)), p)
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return len(p), nil
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}
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func (mmf *MemoryMappedFile) Truncate(off int64) error {
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return nil
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}
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func (mmf *MemoryMappedFile) Close() error {
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mmf.mm.DeleteFileAndMemoryMap()
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return nil
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}
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func (mmf *MemoryMappedFile) GetStat() (datSize int64, modTime time.Time, err error) {
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stat, e := mmf.mm.File.Stat()
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if e == nil {
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return stat.Size(), stat.ModTime(), nil
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}
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return 0, time.Time{}, err
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}
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func (mmf *MemoryMappedFile) String() string {
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return mmf.mm.File.Name()
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}
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