github.com/m3db/m3@v1.5.0/src/x/io/write.go (about)

     1  // Copyright (c) 2020 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 io
    22  
    23  import (
    24  	"bufio"
    25  	"io"
    26  )
    27  
    28  // ResettableWriter is a resettable writer.
    29  type ResettableWriter interface {
    30  	io.Writer
    31  	Flush() error
    32  	Reset(w io.Writer)
    33  }
    34  
    35  // ResettableWriterOptions are options for a resettable writer.
    36  type ResettableWriterOptions struct {
    37  	WriteBufferSize int
    38  }
    39  
    40  // ResettableWriterFn creates a resettable writer.
    41  type ResettableWriterFn func(r io.Writer, opts ResettableWriterOptions) ResettableWriter
    42  
    43  // defaultResettableWriterFn creates a default resettable writer.
    44  func defaultResettableWriterFn() ResettableWriterFn {
    45  	return func(w io.Writer, opts ResettableWriterOptions) ResettableWriter {
    46  		if opts.WriteBufferSize <= 0 {
    47  			return &passthroughResettableWriter{w: w}
    48  		}
    49  		return bufio.NewWriterSize(w, opts.WriteBufferSize)
    50  	}
    51  }
    52  
    53  type passthroughResettableWriter struct {
    54  	w io.Writer
    55  }
    56  
    57  func (p passthroughResettableWriter) Write(b []byte) (n int, err error) {
    58  	return p.w.Write(b)
    59  }
    60  
    61  func (p passthroughResettableWriter) Flush() error {
    62  	return nil
    63  }
    64  
    65  func (p *passthroughResettableWriter) Reset(w io.Writer) {
    66  	p.w = w
    67  }