github.com/m3db/m3@v1.5.0/src/m3em/os/fs/bytes_reader_iter.go (about)

     1  // Copyright (c) 2017 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package fs
    22  
    23  import (
    24  	"github.com/m3db/m3/src/m3em/checksum"
    25  )
    26  
    27  type bytesReaderIter struct {
    28  	bytes []byte
    29  	count int
    30  }
    31  
    32  // NewBytesReaderIter creates a new FileReaderIter to iterate
    33  // over a fixed byte slice.
    34  func NewBytesReaderIter(bytes []byte) FileReaderIter {
    35  	return &bytesReaderIter{
    36  		bytes: bytes,
    37  	}
    38  }
    39  
    40  func (b *bytesReaderIter) Current() []byte {
    41  	if b.count == 1 {
    42  		return b.bytes
    43  	}
    44  	return nil
    45  }
    46  
    47  func (b *bytesReaderIter) Next() bool {
    48  	b.count++
    49  	return b.count == 1
    50  }
    51  
    52  func (b *bytesReaderIter) Err() error {
    53  	return nil
    54  }
    55  
    56  func (b *bytesReaderIter) Checksum() uint32 {
    57  	return checksum.Fn(b.bytes)
    58  }
    59  
    60  func (b *bytesReaderIter) Close() error {
    61  	return nil
    62  }