github.com/zhyoulun/cilium@v1.6.12/pkg/revert/revert.go (about)

     1  // Copyright 2018 Authors of Cilium
     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 revert
    16  
    17  import "fmt"
    18  
    19  // RevertFunc is a function returned by a successful function call, which
    20  // reverts the side-effects of the initial function call. A call that returns
    21  // an error should return a nil RevertFunc.
    22  type RevertFunc func() error
    23  
    24  // RevertStack is a stack of RevertFuncs to be executed in the reverse order
    25  // they were pushed.
    26  type RevertStack struct {
    27  	// revertFuncs is the list of revert functions in the order they were
    28  	// pushed.
    29  	revertFuncs []RevertFunc
    30  }
    31  
    32  // Push pushes the given RevertFunc on top of this stack. If the function is
    33  // nil, it is ignored.
    34  func (s *RevertStack) Push(revertFunc RevertFunc) {
    35  	if revertFunc != nil {
    36  		s.revertFuncs = append(s.revertFuncs, revertFunc)
    37  	}
    38  }
    39  
    40  // Revert executes all the RevertFuncs in the given stack in the reverse order
    41  // they were pushed.
    42  func (s *RevertStack) Revert() error {
    43  	for i := len(s.revertFuncs) - 1; i >= 0; i-- {
    44  		if err := s.revertFuncs[i](); err != nil {
    45  			return fmt.Errorf("failed to execute revert function; skipping %d revert functions: %s", i, err)
    46  		}
    47  	}
    48  	return nil
    49  }