gitlab.com/aquachain/aquachain@v1.17.16-rc3.0.20221018032414-e3ddf1e1c055/common/log/handler_go13.go (about)

     1  // Copyright 2018 The aquachain Authors
     2  // This file is part of the aquachain library.
     3  //
     4  // The aquachain library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The aquachain library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the aquachain library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  // +build !go1.4
    18  
    19  package log
    20  
    21  import (
    22  	"sync/atomic"
    23  	"unsafe"
    24  )
    25  
    26  // swapHandler wraps another handler that may be swapped out
    27  // dynamically at runtime in a thread-safe fashion.
    28  type swapHandler struct {
    29  	handler unsafe.Pointer
    30  }
    31  
    32  func (h *swapHandler) Log(r *Record) error {
    33  	return h.Get().Log(r)
    34  }
    35  
    36  func (h *swapHandler) Get() Handler {
    37  	return *(*Handler)(atomic.LoadPointer(&h.handler))
    38  }
    39  
    40  func (h *swapHandler) Swap(newHandler Handler) {
    41  	atomic.StorePointer(&h.handler, unsafe.Pointer(&newHandler))
    42  }