github.com/m3db/m3@v1.5.1-0.20231129193456-75a402aa583b/src/aggregator/client/ref_count.go (about)

     1  // Copyright (c) 2018 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 client
    22  
    23  import "sync/atomic"
    24  
    25  type destructorFn func()
    26  
    27  type refCount struct {
    28  	destructorFn destructorFn
    29  	n            int32
    30  }
    31  
    32  func (rc *refCount) SetRefCount(n int)             { atomic.StoreInt32(&rc.n, int32(n)) }
    33  func (rc *refCount) SetDestructor(fn destructorFn) { rc.destructorFn = fn }
    34  
    35  func (rc *refCount) IncRef() int {
    36  	if n := int(atomic.AddInt32(&rc.n, 1)); n > 0 {
    37  		return n
    38  	}
    39  	panic("invalid ref count")
    40  }
    41  
    42  func (rc *refCount) DecRef() int {
    43  	if n := int(atomic.AddInt32(&rc.n, -1)); n == 0 {
    44  		if rc.destructorFn != nil {
    45  			rc.destructorFn()
    46  		}
    47  		return n
    48  	} else if n > 0 {
    49  		return n
    50  	}
    51  	panic("invalid ref count")
    52  }