github.com/m3db/m3@v1.5.0/src/x/pool/example_test.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
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     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 pool_test
    22  
    23  import (
    24  	"fmt"
    25  
    26  	"github.com/m3db/m3/src/x/pool"
    27  )
    28  
    29  type exampleObject struct {
    30  	a, b, c int64
    31  }
    32  
    33  func (o *exampleObject) reset() {
    34  	o.a = 0
    35  	o.b = 0
    36  	o.c = 0
    37  }
    38  
    39  func ExampleObjectPool() {
    40  	opts := pool.NewObjectPoolOptions()
    41  	p := pool.NewObjectPool(opts)
    42  	p.Init(func() interface{} {
    43  		// The Pool's Allocator should generally only return pointer
    44  		// types, since a pointer can be put into the return interface
    45  		// value without an allocation.
    46  		return new(exampleObject)
    47  	})
    48  
    49  	// Get an exampleObject from the pool.
    50  	o := p.Get().(*exampleObject)
    51  
    52  	fmt.Printf("Retrieved struct should have default values: %+v", o)
    53  	// Output: Retrieved struct should have default values: &{a:0 b:0 c:0}
    54  
    55  	// Use the exampleObject.
    56  	_ = o
    57  
    58  	// Reset the exampleObject and return it to the pool.
    59  	o.reset()
    60  	p.Put(o)
    61  }