go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/common/exec/execmock/filter.go (about)

     1  // Copyright 2023 The LUCI Authors.
     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 execmock
    16  
    17  import (
    18  	"go.chromium.org/luci/common/data/text/sequence"
    19  	"go.chromium.org/luci/common/exec/internal/execmockctx"
    20  )
    21  
    22  type unsetMatcher struct{}
    23  
    24  var _ sequence.Matcher = unsetMatcher{}
    25  
    26  func (unsetMatcher) Matches(txt string) bool { panic("do not call unsetMatcher.Matches") }
    27  
    28  type filter struct {
    29  	argFilters []sequence.Pattern
    30  	envFilters map[string][]sequence.Matcher
    31  	limit      uint64
    32  
    33  	// literalArgMatchers is a count of the number of LiteralMatcher objects in
    34  	// `argFilters`.
    35  	literalArgMatchers int
    36  
    37  	// argMatchers is a count of all the Matcher objects in `argFilters`.
    38  	argMatchers int
    39  }
    40  
    41  func (f filter) less(other filter) (less, ok bool) {
    42  	switch {
    43  	case f.literalArgMatchers != other.literalArgMatchers:
    44  		// this is inverted; we want more specific (more literal matchers) to come
    45  		// earlier.
    46  		return f.literalArgMatchers > other.literalArgMatchers, true
    47  
    48  	case f.argMatchers != other.argMatchers:
    49  		// this is inverted; we want more specific (more literal matchers) to come
    50  		// earlier.
    51  		return f.argMatchers > other.argMatchers, true
    52  
    53  	case f.limit != other.limit:
    54  		switch {
    55  		case f.limit == 0:
    56  			return false, true
    57  
    58  		case other.limit == 0:
    59  			return true, true
    60  		}
    61  
    62  		return f.limit < other.limit, true
    63  
    64  	case len(f.envFilters) != len(other.argFilters):
    65  		return len(f.envFilters) < len(other.envFilters), true
    66  	}
    67  
    68  	return false, false
    69  }
    70  
    71  func (f filter) matches(mc *execmockctx.MockCriteria) (match bool) {
    72  	for _, pat := range f.argFilters {
    73  		if !pat.In(mc.Args...) {
    74  			return false
    75  		}
    76  	}
    77  	for key, matchers := range f.envFilters {
    78  		for _, mch := range matchers {
    79  			if _, mustBeUnset := mch.(unsetMatcher); mustBeUnset {
    80  				if _, ok := mc.Env.Lookup(key); ok {
    81  					return false
    82  				}
    83  			} else {
    84  				val, ok := mc.Env.Lookup(key)
    85  				if !ok {
    86  					return false
    87  				}
    88  				if !mch.Matches(val) {
    89  					return false
    90  				}
    91  			}
    92  		}
    93  	}
    94  	return true
    95  }
    96  
    97  func (f filter) withArgs(argPattern []string) filter {
    98  	seq, err := sequence.NewPattern(argPattern...)
    99  	if err != nil {
   100  		panic(err)
   101  	}
   102  
   103  	ret := f
   104  
   105  	for _, m := range seq {
   106  		if _, ok := m.(sequence.LiteralMatcher); ok {
   107  			ret.literalArgMatchers++
   108  		}
   109  	}
   110  	ret.argMatchers += len(seq)
   111  
   112  	ret.argFilters = make([]sequence.Pattern, len(f.argFilters), len(f.argFilters)+1)
   113  	copy(ret.argFilters, f.argFilters)
   114  	ret.argFilters = append(ret.argFilters, seq)
   115  
   116  	return ret
   117  }
   118  
   119  func (f filter) withEnv(varName, valuePattern string) filter {
   120  	var pat sequence.Matcher
   121  	if valuePattern == "!" {
   122  		pat = unsetMatcher{}
   123  	} else {
   124  		var err error
   125  		pat, err = sequence.ParseRegLiteral(valuePattern)
   126  		if err != nil {
   127  			panic(err)
   128  		}
   129  	}
   130  
   131  	ret := f
   132  
   133  	ret.envFilters = make(map[string][]sequence.Matcher, len(f.envFilters)+1)
   134  	ret.envFilters[varName] = append(f.envFilters[varName], pat)
   135  
   136  	return ret
   137  }