milvus/internal/storagev2/packed/packed_reader.go

89 lines
2.5 KiB
Go

// Copyright 2023 Zilliz
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package packed
/*
#cgo pkg-config: milvus_core
#include <stdlib.h>
#include "segcore/packed_reader_c.h"
#include "arrow/c/abi.h"
#include "arrow/c/helpers.h"
*/
import "C"
import (
"fmt"
"unsafe"
"github.com/apache/arrow/go/v17/arrow"
"github.com/apache/arrow/go/v17/arrow/cdata"
)
func NewPackedReader(filePaths []string, schema *arrow.Schema, bufferSize int64) (*PackedReader, error) {
cFilePaths := make([]*C.char, len(filePaths))
for i, path := range filePaths {
cFilePaths[i] = C.CString(path)
defer C.free(unsafe.Pointer(cFilePaths[i]))
}
cFilePathsArray := (**C.char)(unsafe.Pointer(&cFilePaths[0]))
cNumPaths := C.int64_t(len(filePaths))
var cas cdata.CArrowSchema
cdata.ExportArrowSchema(schema, &cas)
cSchema := (*C.struct_ArrowSchema)(unsafe.Pointer(&cas))
cBufferSize := C.int64_t(bufferSize)
var cPackedReader C.CPackedReader
status := C.NewPackedReader(cFilePathsArray, cNumPaths, cSchema, cBufferSize, &cPackedReader)
if err := ConsumeCStatusIntoError(&status); err != nil {
return nil, err
}
return &PackedReader{cPackedReader: cPackedReader, schema: schema}, nil
}
func (pr *PackedReader) ReadNext() (arrow.Record, error) {
var cArr C.CArrowArray
var cSchema C.CArrowSchema
status := C.ReadNext(pr.cPackedReader, &cArr, &cSchema)
if err := ConsumeCStatusIntoError(&status); err != nil {
return nil, err
}
if cArr == nil {
return nil, nil // end of stream, no more records to read
}
// Convert ArrowArray to Go RecordBatch using cdata
goCArr := (*cdata.CArrowArray)(unsafe.Pointer(cArr))
goCSchema := (*cdata.CArrowSchema)(unsafe.Pointer(cSchema))
recordBatch, err := cdata.ImportCRecordBatch(goCArr, goCSchema)
if err != nil {
return nil, fmt.Errorf("failed to convert ArrowArray to Record: %w", err)
}
// Return the RecordBatch as an arrow.Record
return recordBatch, nil
}
func (pr *PackedReader) Close() error {
status := C.CloseReader(pr.cPackedReader)
if err := ConsumeCStatusIntoError(&status); err != nil {
return err
}
return nil
}