github.com/westcoastroms/westcoastroms-build@v0.0.0-20190928114312-2350e5a73030/build/blueprint/glob.go (about)

     1  // Copyright 2015 Google Inc. All rights reserved.
     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 blueprint
    16  
    17  import (
    18  	"crypto/md5"
    19  	"fmt"
    20  	"sort"
    21  	"strings"
    22  )
    23  
    24  type GlobPath struct {
    25  	Pattern  string
    26  	Excludes []string
    27  	Files    []string
    28  	Deps     []string
    29  	Name     string
    30  }
    31  
    32  func verifyGlob(fileName, pattern string, excludes []string, g GlobPath) {
    33  	if pattern != g.Pattern {
    34  		panic(fmt.Errorf("Mismatched patterns %q and %q for glob file %q", pattern, g.Pattern, fileName))
    35  	}
    36  	if len(excludes) != len(g.Excludes) {
    37  		panic(fmt.Errorf("Mismatched excludes %v and %v for glob file %q", excludes, g.Excludes, fileName))
    38  	}
    39  
    40  	for i := range excludes {
    41  		if g.Excludes[i] != excludes[i] {
    42  			panic(fmt.Errorf("Mismatched excludes %v and %v for glob file %q", excludes, g.Excludes, fileName))
    43  		}
    44  	}
    45  }
    46  
    47  func (c *Context) glob(pattern string, excludes []string) ([]string, error) {
    48  	fileName := globToFileName(pattern, excludes)
    49  
    50  	// Try to get existing glob from the stored results
    51  	c.globLock.Lock()
    52  	g, exists := c.globs[fileName]
    53  	c.globLock.Unlock()
    54  
    55  	if exists {
    56  		// Glob has already been done, double check it is identical
    57  		verifyGlob(fileName, pattern, excludes, g)
    58  		return g.Files, nil
    59  	}
    60  
    61  	// Get a globbed file list
    62  	files, deps, err := c.fs.Glob(pattern, excludes)
    63  	if err != nil {
    64  		return nil, err
    65  	}
    66  
    67  	// Store the results
    68  	c.globLock.Lock()
    69  	if g, exists = c.globs[fileName]; !exists {
    70  		c.globs[fileName] = GlobPath{pattern, excludes, files, deps, fileName}
    71  	}
    72  	c.globLock.Unlock()
    73  
    74  	// Getting the list raced with another goroutine, throw away the results and use theirs
    75  	if exists {
    76  		verifyGlob(fileName, pattern, excludes, g)
    77  		return g.Files, nil
    78  	}
    79  
    80  	return files, nil
    81  }
    82  
    83  func (c *Context) Globs() []GlobPath {
    84  	fileNames := make([]string, 0, len(c.globs))
    85  	for k := range c.globs {
    86  		fileNames = append(fileNames, k)
    87  	}
    88  	sort.Strings(fileNames)
    89  
    90  	globs := make([]GlobPath, len(fileNames))
    91  	for i, fileName := range fileNames {
    92  		globs[i] = c.globs[fileName]
    93  	}
    94  
    95  	return globs
    96  }
    97  
    98  func globToString(pattern string) string {
    99  	ret := ""
   100  	for _, c := range pattern {
   101  		switch {
   102  		case c >= 'a' && c <= 'z',
   103  			c >= 'A' && c <= 'Z',
   104  			c >= '0' && c <= '9',
   105  			c == '_', c == '-', c == '/':
   106  			ret += string(c)
   107  		default:
   108  			ret += "_"
   109  		}
   110  	}
   111  
   112  	return ret
   113  }
   114  
   115  func globToFileName(pattern string, excludes []string) string {
   116  	name := globToString(pattern)
   117  	excludeName := ""
   118  	for _, e := range excludes {
   119  		excludeName += "__" + globToString(e)
   120  	}
   121  
   122  	// Prevent file names from reaching ninja's path component limit
   123  	if strings.Count(name, "/")+strings.Count(excludeName, "/") > 30 {
   124  		excludeName = fmt.Sprintf("___%x", md5.Sum([]byte(excludeName)))
   125  	}
   126  
   127  	return name + excludeName + ".glob"
   128  }