// ReadBytes reads bytes from a data object at the specified position and length, returns []byte slice and error.
func (obj *DataObj) ReadBytes(pos int64, length int) ([]byte, error) {
if er := obj.init(); er != nil {
return nil, er
}
var (
buffer C.bytesBuf_t
err *C.char
bytesRead C.int
)
if er := obj.LSeek(pos); er != nil {
return nil, er
}
ccon := obj.con.GetCcon()
defer obj.con.ReturnCcon(ccon)
if status := C.gorods_read_dataobject(obj.chandle, C.rodsLong_t(length), &buffer, &bytesRead, ccon, &err); status != 0 {
return nil, newError(Fatal, fmt.Sprintf("iRODS ReadBytes DataObject Failed: %v, %v", obj.path, C.GoString(err)))
}
buf := unsafe.Pointer(buffer.buf)
defer C.free(buf)
data := C.GoBytes(buf, bytesRead)
return data, nil
}
// Put reads the entire file from localPath and adds it the collection, using the options specified.
func (col *Collection) Put(localPath string, opts DataObjOptions) (*DataObj, error) {
var (
errMsg *C.char
force int
resource *C.char
)
if opts.Force {
force = 1
} else {
force = 0
}
if opts.Resource != nil {
switch opts.Resource.(type) {
case string:
resource = C.CString(opts.Resource.(string))
case *Resource:
r := opts.Resource.(*Resource)
resource = C.CString(r.Name())
default:
return nil, newError(Fatal, fmt.Sprintf("Wrong variable type passed in Resource field"))
}
} else {
resource = C.CString("")
}
if opts.Name == "" {
opts.Name = filepath.Base(localPath)
}
path := C.CString(col.path + "/" + opts.Name)
cLocalPath := C.CString(localPath)
defer C.free(unsafe.Pointer(path))
defer C.free(unsafe.Pointer(resource))
defer C.free(unsafe.Pointer(cLocalPath))
ccon := col.con.GetCcon()
if status := C.gorods_put_dataobject(cLocalPath, path, C.rodsLong_t(opts.Size), C.int(opts.Mode), C.int(force), resource, ccon, &errMsg); status != 0 {
col.con.ReturnCcon(ccon)
return nil, newError(Fatal, fmt.Sprintf("iRODS Put DataObject Failed: %v, Does the file already exist?", C.GoString(errMsg)))
}
col.con.ReturnCcon(ccon)
if err := col.Refresh(); err != nil {
return nil, err
}
if do, err := getDataObj(C.GoString(path), col.con); err != nil {
return nil, err
} else {
return do, nil
}
}
// ReadChunk reads the entire data object in chunks (size of chunk specified by size parameter), passing the data into a callback function for each chunk. Use this to read/write large files.
func (obj *DataObj) ReadChunk(size int64, callback func([]byte)) error {
if er := obj.init(); er != nil {
return er
}
var (
buffer C.bytesBuf_t
err *C.char
bytesRead C.int
)
if er := obj.LSeek(0); er != nil {
return er
}
for obj.offset < obj.size {
ccon := obj.con.GetCcon()
if status := C.gorods_read_dataobject(obj.chandle, C.rodsLong_t(size), &buffer, &bytesRead, ccon, &err); status != 0 {
obj.con.ReturnCcon(ccon)
return newError(Fatal, fmt.Sprintf("iRODS Read DataObject Failed: %v, %v", obj.path, C.GoString(err)))
}
obj.con.ReturnCcon(ccon)
buf := unsafe.Pointer(buffer.buf)
chunk := C.GoBytes(buf, bytesRead)
C.free(buf)
callback(chunk)
if er := obj.LSeek(obj.offset + size); er != nil {
return er
}
}
if er := obj.LSeek(0); er != nil {
return er
}
return obj.Close()
}
// LSeek sets the read/write offset pointer of a data object, returns error
func (obj *DataObj) LSeek(offset int64) error {
if er := obj.init(); er != nil {
return er
}
var (
err *C.char
)
ccon := obj.con.GetCcon()
defer obj.con.ReturnCcon(ccon)
if status := C.gorods_lseek_dataobject(obj.chandle, C.rodsLong_t(offset), ccon, &err); status != 0 {
return newError(Fatal, fmt.Sprintf("iRODS LSeek DataObject Failed: %v, %v", obj.path, C.GoString(err)))
}
obj.offset = offset
return nil
}
// Backup is similar to Replicate. In backup mode, if a good copy already exists in this resource group or resource, don't make another one.
func (obj *DataObj) Backup(targetResource interface{}, opts DataObjOptions) error {
var (
err *C.char
resourceStr string
)
switch targetResource.(type) {
case string:
resourceStr = targetResource.(string)
case *Resource:
resourceStr = (targetResource.(*Resource)).Name()
default:
return newError(Fatal, fmt.Sprintf("Unknown type passed as targetResource"))
}
cPath := C.CString(obj.Path())
cResource := C.CString(resourceStr)
defer C.free(unsafe.Pointer(cPath))
defer C.free(unsafe.Pointer(cResource))
ccon := obj.con.GetCcon()
defer obj.con.ReturnCcon(ccon)
if status := C.gorods_repl_dataobject(ccon, cPath, cResource, C.int(1), C.int(opts.Mode), C.rodsLong_t(opts.Size), &err); status != 0 {
return newError(Fatal, fmt.Sprintf("iRODS Backup Failed: %v, %v", obj.path, C.GoString(err)))
}
return nil
}