forked from dfuse-io/dfuse-eosio
/
writer.go
60 lines (50 loc) · 1.59 KB
/
writer.go
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// Copyright 2019 dfuse Platform Inc.
//
// 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 codec
import (
"fmt"
"io"
"github.com/dfuse-io/bstream"
"github.com/dfuse-io/dbin"
"github.com/golang/protobuf/proto"
pbbstream "github.com/invisible-train-40/pbgo/dfuse/bstream/v1"
)
func BlockWriterFactory(writer io.Writer) (bstream.BlockWriter, error) {
return NewBlockWriter(writer)
}
// BlockWriter reads the dbin format where each element is assumed to be a `bstream.Block`.
type BlockWriter struct {
src *dbin.Writer
}
func NewBlockWriter(writer io.Writer) (*BlockWriter, error) {
dbinWriter := dbin.NewWriter(writer)
err := dbinWriter.WriteHeader(pbbstream.Protocol_EOS.String(), 1)
if err != nil {
return nil, fmt.Errorf("unable to write file header: %s", err)
}
return &BlockWriter{
src: dbinWriter,
}, nil
}
func (w *BlockWriter) Write(block *bstream.Block) error {
pbBlock, err := block.ToProto()
if err != nil {
return err
}
bytes, err := proto.Marshal(pbBlock)
if err != nil {
return fmt.Errorf("unable to marshal proto block: %s", err)
}
return w.src.WriteMessage(bytes)
}