github.com/solo-io/cue@v0.4.7/internal/core/runtime/index.go (about)

     1  // Copyright 2020 CUE 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 runtime
    16  
    17  import (
    18  	"sync"
    19  
    20  	"github.com/solo-io/cue/internal"
    21  	"github.com/solo-io/cue/internal/core/adt"
    22  )
    23  
    24  func (r *Runtime) IndexToString(i int64) string {
    25  	return r.index.IndexToString(i)
    26  }
    27  
    28  func (r *Runtime) StringToIndex(s string) int64 {
    29  	return getKey(s)
    30  }
    31  
    32  func (r *Runtime) LabelStr(l adt.Feature) string {
    33  	return l.IdentString(r)
    34  }
    35  
    36  func (r *Runtime) StrLabel(str string) adt.Feature {
    37  	return r.Label(str, false)
    38  }
    39  
    40  func (r *Runtime) Label(s string, isIdent bool) adt.Feature {
    41  	index := r.StringToIndex(s)
    42  	typ := adt.StringLabel
    43  	if isIdent {
    44  		switch {
    45  		case internal.IsDef(s) && internal.IsHidden(s):
    46  			typ = adt.HiddenDefinitionLabel
    47  		case internal.IsDef(s):
    48  			typ = adt.DefinitionLabel
    49  		case internal.IsHidden(s):
    50  			typ = adt.HiddenLabel
    51  		}
    52  	}
    53  	f, _ := adt.MakeLabel(nil, index, typ)
    54  	return f
    55  }
    56  
    57  // TODO: move to Runtime as fields.
    58  var (
    59  	labelMap = map[string]int{}
    60  	labels   = make([]string, 0, 1000)
    61  	mutex    sync.RWMutex
    62  )
    63  
    64  func init() {
    65  	// Ensure label 0 is assigned to _.
    66  	getKey("_")
    67  }
    68  
    69  func getKey(s string) int64 {
    70  	mutex.RLock()
    71  	p, ok := labelMap[s]
    72  	mutex.RUnlock()
    73  	if ok {
    74  		return int64(p)
    75  	}
    76  	mutex.Lock()
    77  	defer mutex.Unlock()
    78  	p, ok = labelMap[s]
    79  	if ok {
    80  		return int64(p)
    81  	}
    82  	p = len(labels)
    83  	labels = append(labels, s)
    84  	labelMap[s] = p
    85  	return int64(p)
    86  }
    87  
    88  func (x *index) IndexToString(i int64) string {
    89  	mutex.RLock()
    90  	s := labels[i]
    91  	mutex.RUnlock()
    92  	return s
    93  }