forked from kisielk/go-hdf5
/
h5d.go
180 lines (148 loc) · 3.84 KB
/
h5d.go
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package hdf5
// #include "hdf5.h"
// #include <stdlib.h>
// #include <string.h>
import "C"
import (
"bytes"
"fmt"
"reflect"
"runtime"
"unsafe"
)
type Dataset struct {
id C.hid_t
}
func newDataset(id C.hid_t) *Dataset {
d := &Dataset{id: id}
runtime.SetFinalizer(d, (*Dataset).finalizer)
return d
}
func createDataset(id C.hid_t, name string, dtype *Datatype, dspace *Dataspace, dcpl *PropList) (*Dataset, error) {
c_name := C.CString(name)
defer C.free(unsafe.Pointer(c_name))
hid := C.H5Dcreate2(id, c_name, dtype.id, dspace.id, P_DEFAULT.id, dcpl.id, P_DEFAULT.id)
if err := h5err(C.herr_t(int(hid))); err != nil {
return nil, err
}
return newDataset(hid), nil
}
func openDataset(id C.hid_t, name string) (*Dataset, error) {
c_name := C.CString(name)
defer C.free(unsafe.Pointer(c_name))
hid := C.H5Dopen2(id, c_name, P_DEFAULT.id)
if err := h5err(C.herr_t(int(hid))); err != nil {
return nil, err
}
return newDataset(hid), nil
}
func (s *Dataset) finalizer() {
err := s.Close()
if err != nil {
panic(fmt.Sprintf("error closing dset: %s", err))
}
}
func (s *Dataset) Name() string {
return getName(s.id)
}
func (s *Dataset) Id() int {
return int(s.id)
}
func (s *Dataset) File() *File {
return getFile(s.id)
}
// Releases and terminates access to a dataset.
func (s *Dataset) Close() error {
if s.id > 0 {
err := C.H5Dclose(s.id)
s.id = 0
return h5err(err)
}
return nil
}
// Returns an identifier for a copy of the dataspace for a dataset.
func (s *Dataset) Space() *Dataspace {
hid := C.H5Dget_space(s.id)
if int(hid) > 0 {
return newDataspace(hid)
}
return nil
}
// Returns an identifier for a copy of the datatype for a dataset.
// hid_t H5Dget_type(hid_t dataset_id )
func (s *Dataset) Type() (*Datatype, error) {
hid := C.H5Dget_type(s.id)
err := h5err(C.herr_t(int(hid)))
if err != nil {
return nil, err
}
dt := NewDatatype(hid, nil)
return dt, err
}
// Reads raw data from a dataset into a buffer.
// herr_t H5Dread(hid_t dataset_id, hid_t mem_type_id, hid_t mem_space_id, hid_t file_space_id, hid_t xfer_plist_id, void * buf )
func (s *Dataset) Read(data interface{}, dtype *Datatype) error {
var addr uintptr
var tmp_slice []byte
post_process := false
v := reflect.ValueOf(data)
//fmt.Printf(":: read[%s]...\n", v.Kind())
switch v.Kind() {
case reflect.Array:
addr = v.UnsafeAddr()
case reflect.Slice:
if v.Index(0).Kind() == reflect.String && C.H5Tis_variable_str(dtype.id) == 0 {
tmp_slice = make([]byte, v.Len()*int(dtype.Size()))
addr = reflect.ValueOf(tmp_slice).Pointer()
post_process = true
} else {
addr = v.Pointer()
}
case reflect.String:
str := (*reflect.StringHeader)(unsafe.Pointer(v.UnsafeAddr()))
addr = str.Data
case reflect.Ptr:
addr = v.Pointer()
default:
addr = v.UnsafeAddr()
}
rc := C.H5Dread(s.id, dtype.id, 0, 0, 0, unsafe.Pointer(addr))
err := h5err(rc)
if err == nil && post_process {
str_len := int(dtype.Size())
p := 0
for i := 0; i < v.Len(); i++ {
str := tmp_slice[p : p+str_len]
n := bytes.Index(str, []byte{0})
if n < 0 {
n = str_len
}
v.Index(i).SetString(string(str[:n]))
p += str_len
}
}
return err
}
// Writes raw data from a buffer to a dataset.
// herr_t H5Dwrite(hid_t dataset_id, hid_t mem_type_id, hid_t mem_space_id, hid_t file_space_id, hid_t xfer_plist_id, const void * buf )
func (s *Dataset) Write(data interface{}, dtype *Datatype) error {
var addr uintptr
v := reflect.ValueOf(data)
//fmt.Printf(":: write[%s]...\n", v.Kind())
switch v.Kind() {
case reflect.Array:
addr = v.UnsafeAddr()
case reflect.Slice:
addr = v.Pointer()
case reflect.String:
str := (*reflect.StringHeader)(unsafe.Pointer(v.UnsafeAddr()))
addr = str.Data
case reflect.Ptr:
addr = v.Pointer()
default:
addr = v.Pointer()
}
rc := C.H5Dwrite(s.id, dtype.id, 0, 0, 0, unsafe.Pointer(addr))
err := h5err(rc)
return err
}