resource_test.go

Documentation: github.com/containerd/continuity

     1  /*
     2     Copyright The containerd Authors.
     3  
     4     Licensed under the Apache License, Version 2.0 (the "License");
     5     you may not use this file except in compliance with the License.
     6     You may obtain a copy of the License at
     7  
     8         http://www.apache.org/licenses/LICENSE-2.0
     9  
    10     Unless required by applicable law or agreed to in writing, software
    11     distributed under the License is distributed on an "AS IS" BASIS,
    12     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13     See the License for the specific language governing permissions and
    14     limitations under the License.
    15  */
    16  
    17  //nolint:unused,deadcode
    18  package continuity
    19  
    20  type resourceUpdate struct {
    21  	Original Resource
    22  	Updated  Resource
    23  }
    24  
    25  type resourceListDifference struct {
    26  	Additions []Resource
    27  	Deletions []Resource
    28  	Updates   []resourceUpdate
    29  }
    30  
    31  func (l resourceListDifference) HasDiff() bool {
    32  	return len(l.Additions) > 0 || len(l.Deletions) > 0 || len(l.Updates) > 0
    33  }
    34  
    35  // diffManifest compares two resource lists and returns the list
    36  // of adds updates and deletes, resource lists are not reordered
    37  // before doing difference.
    38  func diffResourceList(r1, r2 []Resource) resourceListDifference {
    39  	i1 := 0
    40  	i2 := 0
    41  	var d resourceListDifference
    42  
    43  	for i1 < len(r1) && i2 < len(r2) {
    44  		p1 := r1[i1].Path()
    45  		p2 := r2[i2].Path()
    46  		switch {
    47  		case p1 < p2:
    48  			d.Deletions = append(d.Deletions, r1[i1])
    49  			i1++
    50  		case p1 == p2:
    51  			if !compareResource(r1[i1], r2[i2]) {
    52  				d.Updates = append(d.Updates, resourceUpdate{
    53  					Original: r1[i1],
    54  					Updated:  r2[i2],
    55  				})
    56  			}
    57  			i1++
    58  			i2++
    59  		case p1 > p2:
    60  			d.Additions = append(d.Additions, r2[i2])
    61  			i2++
    62  		}
    63  	}
    64  
    65  	for i1 < len(r1) {
    66  		d.Deletions = append(d.Deletions, r1[i1])
    67  		i1++
    68  
    69  	}
    70  	for i2 < len(r2) {
    71  		d.Additions = append(d.Additions, r2[i2])
    72  		i2++
    73  	}
    74  
    75  	return d
    76  }
    77  
    78  func compareResource(r1, r2 Resource) bool {
    79  	if r1.Path() != r2.Path() {
    80  		return false
    81  	}
    82  	if r1.Mode() != r2.Mode() {
    83  		return false
    84  	}
    85  	if r1.UID() != r2.UID() {
    86  		return false
    87  	}
    88  	if r1.GID() != r2.GID() {
    89  		return false
    90  	}
    91  
    92  	// TODO(dmcgowan): Check if is XAttrer
    93  
    94  	switch t1 := r1.(type) {
    95  	case RegularFile:
    96  		t2, ok := r2.(RegularFile)
    97  		if !ok {
    98  			return false
    99  		}
   100  		return compareRegularFile(t1, t2)
   101  	case Directory:
   102  		t2, ok := r2.(Directory)
   103  		if !ok {
   104  			return false
   105  		}
   106  		return compareDirectory(t1, t2)
   107  	case SymLink:
   108  		t2, ok := r2.(SymLink)
   109  		if !ok {
   110  			return false
   111  		}
   112  		return compareSymLink(t1, t2)
   113  	case NamedPipe:
   114  		t2, ok := r2.(NamedPipe)
   115  		if !ok {
   116  			return false
   117  		}
   118  		return compareNamedPipe(t1, t2)
   119  	case Device:
   120  		t2, ok := r2.(Device)
   121  		if !ok {
   122  			return false
   123  		}
   124  		return compareDevice(t1, t2)
   125  	default:
   126  		// TODO(dmcgowan): Should this panic?
   127  		return r1 == r2
   128  	}
   129  }
   130  
   131  func compareRegularFile(r1, r2 RegularFile) bool {
   132  	if r1.Size() != r2.Size() {
   133  		return false
   134  	}
   135  	p1 := r1.Paths()
   136  	p2 := r2.Paths()
   137  	if len(p1) != len(p2) {
   138  		return false
   139  	}
   140  	for i := range p1 {
   141  		if p1[i] != p2[i] {
   142  			return false
   143  		}
   144  	}
   145  	d1 := r1.Digests()
   146  	d2 := r2.Digests()
   147  	if len(d1) != len(d2) {
   148  		return false
   149  	}
   150  	for i := range d1 {
   151  		if d1[i] != d2[i] {
   152  			return false
   153  		}
   154  	}
   155  
   156  	return true
   157  }
   158  
   159  func compareSymLink(r1, r2 SymLink) bool {
   160  	return r1.Target() == r2.Target()
   161  }
   162  
   163  func compareDirectory(r1, r2 Directory) bool {
   164  	return true
   165  }
   166  
   167  func compareNamedPipe(r1, r2 NamedPipe) bool {
   168  	return true
   169  }
   170  
   171  func compareDevice(r1, r2 Device) bool {
   172  	return r1.Major() == r2.Major() && r1.Minor() == r2.Minor()
   173  }
   174
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