goldsmith/goldsmith.go

159 lines
3.5 KiB
Go

package goldsmith
import (
"hash"
"hash/crc32"
"os"
"path/filepath"
"sync"
)
type Goldsmith struct {
sourceDir string
targetDir string
contexts []*Context
contextHasher hash.Hash32
fileRefs map[string]bool
fileFilters []Filter
fileCache *cache
errors []error
mutex sync.Mutex
}
func Begin(sourceDir string) *Goldsmith {
goldsmith := &Goldsmith{
sourceDir: sourceDir,
contextHasher: crc32.NewIEEE(),
fileRefs: make(map[string]bool),
}
goldsmith.Chain(new(loader))
return goldsmith
}
func (goldsmith *Goldsmith) Cache(cacheDir string) *Goldsmith {
goldsmith.fileCache = &cache{cacheDir}
return goldsmith
}
func (goldsmith *Goldsmith) Chain(plugin Plugin) *Goldsmith {
goldsmith.contextHasher.Write([]byte(plugin.Name()))
context := &Context{
goldsmith: goldsmith,
plugin: plugin,
hash: goldsmith.contextHasher.Sum32(),
outputFiles: make(chan *File),
}
context.fileFilters = append(context.fileFilters, goldsmith.fileFilters...)
if len(goldsmith.contexts) > 0 {
context.inputFiles = goldsmith.contexts[len(goldsmith.contexts)-1].outputFiles
}
goldsmith.contexts = append(goldsmith.contexts, context)
return goldsmith
}
func (goldsmith *Goldsmith) FilterPush(filter Filter) *Goldsmith {
goldsmith.fileFilters = append(goldsmith.fileFilters, filter)
return goldsmith
}
func (goldsmith *Goldsmith) FilterPop() *Goldsmith {
count := len(goldsmith.fileFilters)
if count == 0 {
panic("attempted to pop empty filter stack")
}
goldsmith.fileFilters = goldsmith.fileFilters[:count-1]
return goldsmith
}
func (goldsmith *Goldsmith) End(targetDir string) []error {
goldsmith.targetDir = targetDir
for _, context := range goldsmith.contexts {
go context.step()
}
context := goldsmith.contexts[len(goldsmith.contexts)-1]
export:
for file := range context.outputFiles {
for _, fileFilter := range goldsmith.fileFilters {
accept, err := fileFilter.Accept(file)
if err != nil {
goldsmith.fault(fileFilter.Name(), file, err)
continue export
}
if !accept {
continue export
}
}
goldsmith.exportFile(file)
}
goldsmith.removeUnreferencedFiles()
return goldsmith.errors
}
func (goldsmith *Goldsmith) retrieveFile(context *Context, outputPath string, inputFiles []*File) *File {
if goldsmith.fileCache != nil {
outputFile, _ := goldsmith.fileCache.retrieveFile(context, outputPath, inputFiles)
return outputFile
}
return nil
}
func (goldsmith *Goldsmith) storeFile(context *Context, outputFile *File, inputFiles []*File) {
if goldsmith.fileCache != nil {
goldsmith.fileCache.storeFile(context, outputFile, inputFiles)
}
}
func (goldsmith *Goldsmith) removeUnreferencedFiles() {
infos := make(chan fileInfo)
go scanDir(goldsmith.targetDir, infos)
for info := range infos {
if info.path != goldsmith.targetDir {
relPath, _ := filepath.Rel(goldsmith.targetDir, info.path)
if contained, _ := goldsmith.fileRefs[relPath]; !contained {
os.RemoveAll(info.path)
}
}
}
}
func (goldsmith *Goldsmith) exportFile(file *File) error {
if err := file.export(goldsmith.targetDir); err != nil {
return err
}
for pathSeg := cleanPath(file.sourcePath); pathSeg != "."; pathSeg = filepath.Dir(pathSeg) {
goldsmith.fileRefs[pathSeg] = true
}
return nil
}
func (goldsmith *Goldsmith) fault(pluginName string, file *File, err error) {
goldsmith.mutex.Lock()
defer goldsmith.mutex.Unlock()
faultError := &Error{Name: pluginName, Err: err}
if file != nil {
faultError.Path = file.sourcePath
}
goldsmith.errors = append(goldsmith.errors, faultError)
}