github.phpd.cn/cilium/cilium@v1.6.12/test/helpers/buffer.go (about)

     1  // Copyright 2018 Authors of Cilium
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package helpers
    16  
    17  import (
    18  	"bytes"
    19  
    20  	"github.com/cilium/cilium/pkg/lock"
    21  )
    22  
    23  // A Buffer is a variable-sized buffer of bytes with Read and Write methods.
    24  // The zero value for Buffer is an empty buffer ready to use.
    25  type Buffer struct {
    26  	buffer bytes.Buffer
    27  	mutex  lock.Mutex
    28  }
    29  
    30  // Write appends the contents of p to the buffer, growing the buffer as
    31  // needed. The return value n is the length of p; err is always nil. If the
    32  // buffer becomes too large, Write will panic with ErrTooLarge.
    33  func (buf *Buffer) Write(p []byte) (n int, err error) {
    34  	buf.mutex.Lock()
    35  	r, err := buf.buffer.Write(p)
    36  	buf.mutex.Unlock()
    37  	return r, err
    38  }
    39  
    40  // String returns the contents of the unread portion of the buffer
    41  // as a string. If the Buffer is a nil pointer, it returns "<nil>".
    42  //
    43  // To build strings more efficiently, see the strings.Builder type.
    44  func (buf *Buffer) String() string {
    45  	buf.mutex.Lock()
    46  	r := buf.buffer.String()
    47  	buf.mutex.Unlock()
    48  	return r
    49  }
    50  
    51  // Reset resets the buffer to be empty,
    52  // but it retains the underlying storage for use by future writes.
    53  // Reset is the same as Truncate(0).
    54  func (buf *Buffer) Reset() {
    55  	buf.mutex.Lock()
    56  	buf.buffer.Reset()
    57  	buf.mutex.Unlock()
    58  }
    59  
    60  // Len returns the number of bytes of the unread portion of the buffer;
    61  // b.Len() == len(b.Bytes()).
    62  func (buf *Buffer) Len() int {
    63  	buf.mutex.Lock()
    64  	r := buf.buffer.Len()
    65  	buf.mutex.Unlock()
    66  	return r
    67  }
    68  
    69  // Bytes returns a slice of length b.Len() holding the unread portion of the buffer.
    70  // The slice is valid for use only until the next buffer modification (that is,
    71  // only until the next call to a method like Read, Write, Reset, or Truncate).
    72  // The slice aliases the buffer content at least until the next buffer modification,
    73  // so immediate changes to the slice will affect the result of future reads.
    74  func (buf *Buffer) Bytes() []byte {
    75  	buf.mutex.Lock()
    76  	r := buf.buffer.Bytes()
    77  	buf.mutex.Unlock()
    78  	return r
    79  }