github.com/weaviate/weaviate@v1.24.6/entities/diskio/metered_reader_test.go (about)

     1  //                           _       _
     2  // __      _____  __ ___   ___  __ _| |_ ___
     3  // \ \ /\ / / _ \/ _` \ \ / / |/ _` | __/ _ \
     4  //  \ V  V /  __/ (_| |\ V /| | (_| | ||  __/
     5  //   \_/\_/ \___|\__,_| \_/ |_|\__,_|\__\___|
     6  //
     7  //  Copyright © 2016 - 2024 Weaviate B.V. All rights reserved.
     8  //
     9  //  CONTACT: hello@weaviate.io
    10  //
    11  
    12  package diskio
    13  
    14  import (
    15  	"bytes"
    16  	"io"
    17  	"testing"
    18  
    19  	"github.com/stretchr/testify/assert"
    20  	"github.com/stretchr/testify/require"
    21  )
    22  
    23  func TestMeteredReader(t *testing.T) {
    24  	data := make([]byte, 128)
    25  
    26  	t.Run("happy path - with callback", func(t *testing.T) {
    27  		var (
    28  			read int64
    29  			took int64
    30  		)
    31  
    32  		cb := func(r int64, n int64) {
    33  			read = r
    34  			took = n
    35  		}
    36  
    37  		mr := NewMeteredReader(bytes.NewReader(data), cb)
    38  
    39  		target := make([]byte, 128)
    40  		n, err := mr.Read(target)
    41  
    42  		require.Nil(t, err)
    43  		assert.Equal(t, int64(n), read)
    44  		assert.Greater(t, took, int64(0))
    45  	})
    46  
    47  	t.Run("happy path - without callback", func(t *testing.T) {
    48  		mr := NewMeteredReader(bytes.NewReader(data), nil)
    49  
    50  		target := make([]byte, 128)
    51  		_, err := mr.Read(target)
    52  		require.Nil(t, err)
    53  	})
    54  
    55  	t.Run("with an error", func(t *testing.T) {
    56  		var (
    57  			read int64
    58  			took int64
    59  		)
    60  
    61  		cb := func(r int64, n int64) {
    62  			read = r
    63  			took = n
    64  		}
    65  
    66  		underlying := bytes.NewReader(data)
    67  		// provoke EOF error by seeking to end of data
    68  		underlying.Seek(128, 0)
    69  		mr := NewMeteredReader(underlying, cb)
    70  
    71  		target := make([]byte, 128)
    72  		_, err := mr.Read(target)
    73  
    74  		assert.Equal(t, io.EOF, err)
    75  
    76  		// callback should not have been called in error cases, so we expect to
    77  		// read initial values
    78  		assert.Equal(t, int64(0), read)
    79  		assert.Equal(t, int64(0), took)
    80  	})
    81  }