kythe.io@v0.0.68-0.20240422202219-7225dbc01741/kythe/go/platform/delimited/copy.go (about)

     1  /*
     2   * Copyright 2016 The Kythe Authors. All rights reserved.
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *   http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package delimited
    18  
    19  import (
    20  	"fmt"
    21  	"io"
    22  )
    23  
    24  // A Source represents a sequence of records.
    25  type Source interface {
    26  	// Next returns the next record in the sequence, or io.EOF when no further
    27  	// records are available. The slice returned by Next is only required to be
    28  	// valid until a subsequent call to Next.
    29  	Next() ([]byte, error)
    30  }
    31  
    32  // A Sink represents a receiver of records.
    33  type Sink interface {
    34  	// Put delivers a record to the sink.
    35  	Put([]byte) error
    36  }
    37  
    38  // Copy sequentially copies each record read from src to sink until src.Next()
    39  // returns io.EOF or another error occurs.
    40  func Copy(sink Sink, src Source) error {
    41  	for {
    42  		record, err := src.Next()
    43  		if err == io.EOF {
    44  			return nil
    45  		} else if err != nil {
    46  			return fmt.Errorf("copy: read error: %v", err)
    47  		}
    48  		if err := sink.Put(record); err != nil {
    49  			return fmt.Errorf("copy: write error: %v", err)
    50  		}
    51  	}
    52  }