/
mem.go
103 lines (83 loc) · 2.48 KB
/
mem.go
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// Copyright 2019 the Go-FUSE Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package fs
import (
"context"
"sync"
"syscall"
"github.com/hanwen/go-fuse/v2/fuse"
)
// MemRegularFile is a filesystem node that holds a read-only data
// slice in memory.
type MemRegularFile struct {
Inode
mu sync.Mutex
Data []byte
Attr fuse.Attr
}
var _ = (NodeOpener)((*MemRegularFile)(nil))
var _ = (NodeReader)((*MemRegularFile)(nil))
var _ = (NodeWriter)((*MemRegularFile)(nil))
var _ = (NodeSetattrer)((*MemRegularFile)(nil))
var _ = (NodeFlusher)((*MemRegularFile)(nil))
func (f *MemRegularFile) Open(ctx context.Context, flags uint32) (fh FileHandle, fuseFlags uint32, errno syscall.Errno) {
return nil, fuse.FOPEN_KEEP_CACHE, OK
}
func (f *MemRegularFile) Write(ctx context.Context, fh FileHandle, data []byte, off int64) (uint32, syscall.Errno) {
f.mu.Lock()
defer f.mu.Unlock()
end := int64(len(data)) + off
if int64(len(f.Data)) < end {
n := make([]byte, end)
copy(n, f.Data)
f.Data = n
}
copy(f.Data[off:off+int64(len(data))], data)
return uint32(len(data)), 0
}
var _ = (NodeGetattrer)((*MemRegularFile)(nil))
func (f *MemRegularFile) Getattr(ctx context.Context, fh FileHandle, out *fuse.AttrOut) syscall.Errno {
f.mu.Lock()
defer f.mu.Unlock()
out.Attr = f.Attr
out.Attr.Size = uint64(len(f.Data))
return OK
}
func (f *MemRegularFile) Setattr(ctx context.Context, fh FileHandle, in *fuse.SetAttrIn, out *fuse.AttrOut) syscall.Errno {
f.mu.Lock()
defer f.mu.Unlock()
if sz, ok := in.GetSize(); ok {
f.Data = f.Data[:sz]
}
out.Attr = f.Attr
out.Size = uint64(len(f.Data))
return OK
}
func (f *MemRegularFile) Flush(ctx context.Context, fh FileHandle) syscall.Errno {
return 0
}
func (f *MemRegularFile) Read(ctx context.Context, fh FileHandle, dest []byte, off int64) (fuse.ReadResult, syscall.Errno) {
f.mu.Lock()
defer f.mu.Unlock()
end := int(off) + len(dest)
if end > len(f.Data) {
end = len(f.Data)
}
return fuse.ReadResultData(f.Data[off:end]), OK
}
// MemSymlink is an inode holding a symlink in memory.
type MemSymlink struct {
Inode
Attr fuse.Attr
Data []byte
}
var _ = (NodeReadlinker)((*MemSymlink)(nil))
func (l *MemSymlink) Readlink(ctx context.Context) ([]byte, syscall.Errno) {
return l.Data, OK
}
var _ = (NodeGetattrer)((*MemSymlink)(nil))
func (l *MemSymlink) Getattr(ctx context.Context, fh FileHandle, out *fuse.AttrOut) syscall.Errno {
out.Attr = l.Attr
return OK
}