github.com/nvi-inc/fsgo@v0.2.1/versions/fs9.12.11/main.go (about)

     1  // Copyright 2019 NVI Inc. All rights reserved.
     2  // Use of this source code is governed by a MIT
     3  // license that can be found in the LICENSE file.
     4  
     5  package fs
     6  
     7  import (
     8  	"unsafe"
     9  
    10  	"github.com/nvi-inc/fsgo/versions"
    11  	"github.com/nvi-inc/svipc"
    12  )
    13  
    14  type FieldSystem struct {
    15  	Version string `json:"version"`
    16  	Fscom   *Fscom `json:"shm"`
    17  	// TODO(dh): Allow different installation paths
    18  }
    19  
    20  func (f *FieldSystem) Attach() (err error) {
    21  	key, err := svipc.Ftok(SHM_PATH, SHM_ID)
    22  	if err != nil {
    23  		return
    24  	}
    25  	id, err := svipc.Shmget(key, unsafe.Sizeof(&Fscom{}), 0666)
    26  	if err != nil {
    27  		return
    28  	}
    29  	//TODO(dh): test out writing
    30  	ptr, err := svipc.Shmat(id, 0, svipc.SHM_RDONLY)
    31  	if err != nil {
    32  		return
    33  	}
    34  	f.Fscom = (*Fscom)(ptr)
    35  	return
    36  }
    37  
    38  func init() {
    39  	versions.Add(FieldSystemVersion, func() versions.FieldSystem {
    40  		return &FieldSystem{Version: FieldSystemVersion}
    41  	})
    42  }