github.com/hasnat/dolt/go@v0.0.0-20210628190320-9eb5d843fbb7/libraries/utils/async/async_read_test.go (about)

     1  // Copyright 2020 Dolthub, Inc.
     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 async
    16  
    17  import (
    18  	"context"
    19  	"fmt"
    20  	"io"
    21  	"math/rand"
    22  	"testing"
    23  
    24  	"github.com/stretchr/testify/assert"
    25  	"github.com/stretchr/testify/require"
    26  )
    27  
    28  func TestReader(t *testing.T) {
    29  	testReadNItems(t, 0, 32)
    30  	testReadNItems(t, 1, 32)
    31  	testReadNItems(t, 65536, 32)
    32  
    33  	const maxItems = 4 * 1024
    34  	const minItems = 4
    35  	const maxTestBufferSize = 128
    36  
    37  	for i := 0; i < 32; i++ {
    38  		testReadNItems(t, rand.Int63n(maxItems-minItems)+minItems, rand.Int63n(maxTestBufferSize-1)+1)
    39  	}
    40  }
    41  
    42  func testReadNItems(t *testing.T, n int64, bufferSize int64) {
    43  	t.Run(fmt.Sprintf("%d_%d", n, bufferSize), func(t *testing.T) {
    44  		arr := make([]int64, n)
    45  
    46  		for i := int64(0); i < n; i++ {
    47  			arr[i] = i
    48  		}
    49  
    50  		readFunc := readFuncForArr(arr)
    51  		rd := NewAsyncReader(readFunc, 32)
    52  		err := rd.Start(context.Background())
    53  		require.NoError(t, err)
    54  
    55  		res := make([]int64, 0)
    56  		for {
    57  			val, err := rd.Read()
    58  
    59  			if err == io.EOF {
    60  				break
    61  			}
    62  
    63  			assert.NoError(t, err)
    64  			res = append(res, val.(int64))
    65  		}
    66  
    67  		err = rd.Close()
    68  		require.NoError(t, err)
    69  
    70  		assert.Equal(t, arr, res)
    71  	})
    72  }
    73  
    74  func readFuncForArr(arr []int64) ReadFunc {
    75  	pos := 0
    76  	return func(ctx context.Context) (interface{}, error) {
    77  		if pos >= len(arr) {
    78  			return nil, io.EOF
    79  		}
    80  
    81  		val := arr[pos]
    82  		pos++
    83  
    84  		return val, nil
    85  	}
    86  }