Golang parallel.NewRun函數代碼示例

// RemoveAll removes a tree recursively.
func RemoveAll(path string, vfs rwvfs.WalkableFileSystem) error {
	w := fs.WalkFS(path, vfs)

	remove := func(par *parallel.Run, path string) {
		par.Do(func() error { return vfs.Remove(path) })
	}

	var dirs []string // remove dirs after removing all files
	filesPar := parallel.NewRun(20)
	for w.Step() {
		if err := w.Err(); err != nil {
			return err
		}
		if w.Stat().IsDir() {
			dirs = append(dirs, w.Path())
		} else {
			remove(filesPar, w.Path())
		}
	}

	if err := filesPar.Wait(); err != nil {
		return err
	}

	dirsPar := parallel.NewRun(20)
	sort.Sort(sort.Reverse(sort.StringSlice(dirs))) // reverse so we delete leaf dirs first
	for _, dir := range dirs {
		remove(dirsPar, dir)
	}
	return dirsPar.Wait()
}

func (s unitStores) Defs(fs ...DefFilter) ([]*graph.Def, error) {
	uss, err := openUnitStores(s.opener, fs)
	if err != nil {
		return nil, err
	}

	var (
		allDefs   []*graph.Def
		allDefsMu sync.Mutex
	)
	par := parallel.NewRun(storeFetchPar)
	for u_, us_ := range uss {
		u, us := u_, us_
		if us == nil {
			continue
		}

		par.Do(func() error {
			defs, err := us.Defs(filtersForUnit(u, fs).([]DefFilter)...)
			if err != nil && !isStoreNotExist(err) {
				return err
			}
			for _, def := range defs {
				def.UnitType = u.Type
				def.Unit = u.Name
			}
			allDefsMu.Lock()
			allDefs = append(allDefs, defs...)
			allDefsMu.Unlock()
			return nil
		})
	}
	err = par.Wait()
	return allDefs, err
}

func (s repoStores) Defs(f ...DefFilter) ([]*graph.Def, error) {
	rss, err := openRepoStores(s.opener, f)
	if err != nil {
		return nil, err
	}

	var (
		allDefs   []*graph.Def
		allDefsMu sync.Mutex
	)
	par := parallel.NewRun(storeFetchPar)
	for repo_, rs_ := range rss {
		repo, rs := repo_, rs_
		if rs == nil {
			continue
		}

		par.Do(func() error {
			defs, err := rs.Defs(filtersForRepo(repo, f).([]DefFilter)...)
			if err != nil && !isStoreNotExist(err) {
				return err
			}
			for _, def := range defs {
				def.Repo = repo
			}
			allDefsMu.Lock()
			allDefs = append(allDefs, defs...)
			allDefsMu.Unlock()
			return nil
		})
	}
	err = par.Wait()
	return allDefs, err
}

func OpenRepo(dir string) (*Repo, error) {
	if fi, err := os.Stat(dir); err != nil || !fi.Mode().IsDir() {
		return nil, fmt.Errorf("not a directory: %q", dir)
	}

	rc := new(Repo)

	// VCS and root directory
	var err error
	rc.RootDir, rc.VCSType, err = getRootDir(dir)
	if err != nil {
		return nil, fmt.Errorf("detecting git/hg repository in %s: %s", dir, err)
	}
	if rc.RootDir == "" {
		return nil, fmt.Errorf("no git/hg repository found in or above %s", dir)
	}

	par := parallel.NewRun(4)
	par.Do(func() error {
		// Current commit ID
		var err error
		rc.CommitID, err = resolveWorkingTreeRevision(rc.VCSType, rc.RootDir)
		return err
	})
	par.Do(func() error {
		// Get repo URI from clone URL.
		rc.CloneURL = getVCSCloneURL(rc.VCSType, rc.RootDir)
		return nil
	})
	return rc, par.Wait()
}

func (s repoStores) Units(f ...UnitFilter) ([]*unit.SourceUnit, error) {
	rss, err := openRepoStores(s.opener, f)
	if err != nil {
		return nil, err
	}

	var (
		allUnits   []*unit.SourceUnit
		allUnitsMu sync.Mutex
	)
	par := parallel.NewRun(storeFetchPar)
	for repo_, rs_ := range rss {
		repo, rs := repo_, rs_
		if rs == nil {
			continue
		}

		par.Do(func() error {
			units, err := rs.Units(filtersForRepo(repo, f).([]UnitFilter)...)
			if err != nil && !isStoreNotExist(err) {
				return err
			}
			for _, unit := range units {
				unit.Repo = repo
			}
			allUnitsMu.Lock()
			allUnits = append(allUnits, units...)
			allUnitsMu.Unlock()
			return nil
		})
	}
	err = par.Wait()
	return allUnits, err
}

// refsAtOffsets reads the refs at the given serialized byte offsets
// from the ref data file and returns them in arbitrary order.
func (s *fsUnitStore) refsAtOffsets(ofs byteOffsets, fs []RefFilter) (refs []*graph.Ref, err error) {
	vlog.Printf("%s: reading refs at %d offsets with filters %v...", s, len(ofs), fs)
	f, err := openFetcherOrOpen(s.fs, unitRefsFilename)
	if err != nil {
		return nil, err
	}
	defer func() {
		err2 := f.Close()
		if err == nil {
			err = err2
		}
	}()

	ffs := refFilters(fs)

	p := parFetches(s.fs, fs)
	if p == 0 {
		return nil, nil
	}

	var refsLock sync.Mutex
	par := parallel.NewRun(p)
	for _, ofs_ := range ofs {
		ofs := ofs_
		par.Do(func() error {
			if _, moreOK := LimitRemaining(fs); !moreOK {
				return nil
			}

			// Guess how many bytes this ref is. The s3vfs (if that's the
			// VFS impl in use) will autofetch beyond that if needed.
			const byteEstimate = decodeBufSize
			r, err := rangeReader(s.fs, unitRefsFilename, f, ofs, byteEstimate)
			if err != nil {
				return err
			}
			dec := Codec.NewDecoder(r)
			var ref graph.Ref
			if _, err := dec.Decode(&ref); err != nil {
				return err
			}
			if ffs.SelectRef(&ref) {
				refsLock.Lock()
				refs = append(refs, &ref)
				refsLock.Unlock()
			}
			return nil
		})
	}
	if err := par.Wait(); err != nil {
		return refs, err
	}
	sort.Sort(refsByFileStartEnd(refs))
	vlog.Printf("%s: read %v refs at %d offsets with filters %v.", s, len(refs), len(ofs), fs)
	return refs, nil
}

func (c *BuildDataFetchCmd) Execute(args []string) error {
	localFS, localRepoLabel, err := c.getLocalFileSystem()
	if err != nil {
		return err
	}

	remoteFS, remoteRepoLabel, repoRevSpec, err := c.getRemoteFileSystem()
	if err != nil {
		return err
	}

	// Use uncached API client because the .srclib-cache already
	// caches it, and we want to be able to stream large files.
	//
	// TODO(sqs): this uncached client isn't authed because it doesn't
	// have the other API client's http.Client or http.RoundTripper
	cl := newAPIClientWithAuth(false)
	remoteFS, err = cl.BuildData.FileSystem(repoRevSpec)
	if err != nil {
		return err
	}

	if GlobalOpt.Verbose {
		log.Printf("Fetching remote build files for %s to %s...", remoteRepoLabel, localRepoLabel)
	}

	// TODO(sqs): check if file exists in local cache and don't fetch it if it does and if it is identical

	par := parallel.NewRun(8)
	w := fs.WalkFS(".", rwvfs.Walkable(remoteFS))
	for w.Step() {
		path := w.Path()
		if err := w.Err(); err != nil {
			if path == "." {
				log.Printf("# No build data to pull from %s", remoteRepoLabel)
				return nil
			}
			return fmt.Errorf("walking remote dir tree: %s", err)
		}
		fi := w.Stat()
		if fi == nil {
			continue
		}
		if !fi.Mode().IsRegular() {
			continue
		}
		par.Do(func() error {
			return fetchFile(remoteFS, localFS, path, fi, c.DryRun)
		})
	}
	if err := par.Wait(); err != nil {
		return fmt.Errorf("error fetching: %s", err)
	}
	return nil
}

// BuildIndexes builds all indexes on store and its lower-level stores
// that match the specified criteria. It returns the status of each
// index that was built (or rebuilt).
func BuildIndexes(store interface{}, c IndexCriteria, indexChan chan<- IndexStatus) ([]IndexStatus, error) {
	var built []IndexStatus
	var builtMu sync.Mutex
	indexChan2 := make(chan IndexStatus)
	done := make(chan struct{})
	go func() {
		var par *parallel.Run
		lastDependsOnChildren := false
		for sx := range indexChan2 {
			doBuild := func(sx IndexStatus) {
				start := time.Now()
				err := sx.store.BuildIndex(sx.Name, sx.index)
				sx.BuildDuration = time.Since(start)
				if err == nil {
					sx.Stale = false
				} else {
					sx.BuildError = err.Error()
				}
				builtMu.Lock()
				built = append(built, sx)
				builtMu.Unlock()
				if indexChan != nil {
					indexChan <- sx
				}
			}

			// Run indexes in parallel, but if we
			// encounter an index that depends on children, wait for
			// all previously seen indexes to finish before building
			// those indexes.
			if sx.DependsOnChildren != lastDependsOnChildren && par != nil {
				par.Wait()
				par = nil
			}
			if par == nil {
				par = parallel.NewRun(MaxIndexParallel)
			}
			sx_ := sx
			par.Do(func() error { doBuild(sx_); return nil })

			lastDependsOnChildren = sx.DependsOnChildren
		}
		if par != nil {
			par.Wait()
		}
		done <- struct{}{}
	}()
	err := listIndexes(store, c, indexChan2, nil)
	close(indexChan2)
	<-done
	return built, err
}

func (s unitStores) Refs(f ...RefFilter) ([]*graph.Ref, error) {
	uss, err := openUnitStores(s.opener, f)
	if err != nil {
		return nil, err
	}

	c_unitStores_Refs_last_numUnitsQueried = 0
	var (
		allRefsMu sync.Mutex
		allRefs   []*graph.Ref
	)
	par := parallel.NewRun(storeFetchPar)
	for u, us := range uss {
		if us == nil {
			continue
		}
		u, us := u, us

		c_unitStores_Refs_last_numUnitsQueried++

		par.Do(func() error {
			if _, moreOK := LimitRemaining(f); !moreOK {
				return nil
			}
			fCopy := filtersForUnit(u, f).([]RefFilter)
			fCopy = withImpliedUnit(fCopy, u)

			refs, err := us.Refs(fCopy...)
			if err != nil && !isStoreNotExist(err) {
				return err
			}
			for _, ref := range refs {
				ref.UnitType = u.Type
				ref.Unit = u.Name
				if ref.DefUnitType == "" {
					ref.DefUnitType = u.Type
				}
				if ref.DefUnit == "" {
					ref.DefUnit = u.Name
				}
			}

			allRefsMu.Lock()
			allRefs = append(allRefs, refs...)
			allRefsMu.Unlock()
			return nil
		})
	}
	err = par.Wait()
	return allRefs, err
}

// ReadCached reads a Tree's configuration from all of its source unit
// definition files (which may either be in a local VFS rooted at a
// .srclib-cache/<COMMITID> dir, or a remote VFS). It does not read
// the Srcfile; the Srcfile's directives are already accounted for in
// the cached source unit definition files.
//
// bdfs should be a VFS obtained from a call to
// (buildstore.RepoBuildStore).Commit.
func ReadCached(bdfs vfs.FileSystem) (*Tree, error) {
	if _, err := bdfs.Lstat("."); os.IsNotExist(err) {
		return nil, fmt.Errorf("build cache dir does not exist (did you run `srclib config` to create it)?")
	} else if err != nil {
		return nil, err
	}

	// Collect all **/*.unit.json files.
	var unitFiles []string
	unitSuffix := buildstore.DataTypeSuffix(unit.SourceUnit{})
	w := fs.WalkFS(".", rwvfs.Walkable(rwvfs.ReadOnly(bdfs)))
	for w.Step() {
		if err := w.Err(); err != nil {
			return nil, err
		}
		if path := w.Path(); strings.HasSuffix(path, unitSuffix) {
			unitFiles = append(unitFiles, path)
		}
	}

	// Parse units
	sort.Strings(unitFiles)
	units := make([]*unit.SourceUnit, len(unitFiles))
	par := parallel.NewRun(runtime.GOMAXPROCS(0))
	for i_, unitFile_ := range unitFiles {
		i, unitFile := i_, unitFile_
		par.Do(func() error {
			f, err := bdfs.Open(unitFile)
			if err != nil {
				return err
			}
			if err := json.NewDecoder(f).Decode(&units[i]); err != nil {
				f.Close()
				return err
			}
			if err := f.Close(); err != nil {
				return err
			}
			return nil
		})
	}
	if err := par.Wait(); err != nil {
		return nil, err
	}
	return &Tree{SourceUnits: units}, nil
}

func brokenRefsOnly(refs []*graph.Ref, s interface{}) ([]*graph.Ref, error) {
	uniqRefDefs := map[graph.DefKey][]*graph.Ref{}
	loggedDefRepos := map[string]struct{}{}
	for _, ref := range refs {
		if ref.Repo != ref.DefRepo {
			if _, logged := loggedDefRepos[ref.DefRepo]; !logged {
				// TODO(sqs): need to skip these because we don't know the
				// "DefCommitID" in the def's repo, and ByDefKey requires
				// the key to have a CommitID.
				log.Printf("WARNING: Can't check resolution of cross-repo ref (ref.Repo=%q != ref.DefRepo=%q) - cross-repo ref checking is not yet implemented. (This log message will not be repeated.)", ref.Repo, ref.DefRepo)
				loggedDefRepos[ref.DefRepo] = struct{}{}
			}
			continue
		}
		def := ref.DefKey()
		def.CommitID = ref.CommitID
		uniqRefDefs[def] = append(uniqRefDefs[def], ref)
	}

	var (
		brokenRefs  []*graph.Ref
		brokenRefMu sync.Mutex
		par         = parallel.NewRun(runtime.GOMAXPROCS(0))
	)
	for def_, refs_ := range uniqRefDefs {
		def, refs := def_, refs_
		par.Do(func() error {
			defs, err := s.(store.RepoStore).Defs(store.ByDefKey(def))
			if err != nil {
				return err
			}
			if len(defs) == 0 {
				brokenRefMu.Lock()
				brokenRefs = append(brokenRefs, refs...)
				brokenRefMu.Unlock()
			}
			return nil
		})
	}
	err := par.Wait()
	sort.Sort(graph.Refs(brokenRefs))
	return brokenRefs, err
}

func TestParallelMaxPar(t *testing.T) {
	const (
		totalDo = 10
		maxPar  = 3
	)
	var mu sync.Mutex
	max := 0
	n := 0
	tot := 0
	r := parallel.NewRun(maxPar)
	for i := 0; i < totalDo; i++ {
		r.Do(func() error {
			mu.Lock()
			tot++
			n++
			if n > max {
				max = n
			}
			mu.Unlock()
			time.Sleep(0.1e9)
			mu.Lock()
			n--
			mu.Unlock()
			return nil
		})
	}
	err := r.Wait()
	if n != 0 {
		t.Errorf("%d functions still running", n)
	}
	if tot != totalDo {
		t.Errorf("all functions not executed; want %d got %d", totalDo, tot)
	}
	if err != nil {
		t.Errorf("wrong error; want nil got %v", err)
	}
	if max != maxPar {
		t.Errorf("wrong number of do's ran at once; want %d got %d", maxPar, max)
	}
}

func OpenRepo(dir string) (*Repo, error) {
	if fi, err := os.Stat(dir); err != nil || !fi.Mode().IsDir() {
		return nil, fmt.Errorf("not a directory: %q", dir)
	}

	rc := new(Repo)

	// VCS and root directory
	var err error
	rc.RootDir, rc.VCSType, err = getRootDir(dir)
	if err != nil || rc.RootDir == "" {
		log.Printf("Failed to detect git/hg repository root dir for %q; continuing.", dir)
		// Be permissive and return a repo even if there is no git/hg repository.
		wd, err := os.Getwd()
		if err != nil {
			return nil, err
		}
		rc.RootDir = wd
		// TODO: Ensure that builds without commit ids are successful.
		rc.CommitID = "ffffffffffffffffffffffffffffffffffffffff"
		rc.VCSType = ""
		rc.CloneURL = ""
		return rc, nil
	}

	par := parallel.NewRun(4)
	par.Do(func() error {
		// Current commit ID
		var err error
		rc.CommitID, err = resolveWorkingTreeRevision(rc.VCSType, rc.RootDir)
		return err
	})
	par.Do(func() error {
		// Get repo URI from clone URL.
		rc.CloneURL = getVCSCloneURL(rc.VCSType, rc.RootDir)
		return nil
	})
	return rc, par.Wait()
}

func TestParallelError(t *testing.T) {
	const (
		totalDo = 10
		errDo   = 5
	)
	r := parallel.NewRun(6)
	for i := 0; i < totalDo; i++ {
		i := i
		if i >= errDo {
			r.Do(func() error {
				return intError(i)
			})
		} else {
			r.Do(func() error {
				return nil
			})
		}
	}
	err := r.Wait()
	if err == nil {
		t.Fatalf("expected error, got none")
	}
	errs := err.(parallel.Errors)
	if len(errs) != totalDo-errDo {
		t.Fatalf("wrong error count; want %d got %d", len(errs), totalDo-errDo)
	}
	ints := make([]int, len(errs))
	for i, err := range errs {
		ints[i] = int(err.(intError))
	}
	sort.Ints(ints)
	for i, n := range ints {
		if n != i+errDo {
			t.Errorf("unexpected error value; want %d got %d", i+errDo, n)
		}
	}
}

// ScanMulti runs multiple scanner tools in parallel. It passes command-line
// options from opt to each one, and it sends the JSON representation of cfg
// (the repo/tree's Config) to each tool's stdin.
func ScanMulti(scanners []toolchain.Tool, opt Options, treeConfig map[string]interface{}) ([]*unit.SourceUnit, error) {
	if treeConfig == nil {
		treeConfig = map[string]interface{}{}
	}

	var (
		units []*unit.SourceUnit
		mu    sync.Mutex
	)

	run := parallel.NewRun(runtime.GOMAXPROCS(0))
	for _, scanner_ := range scanners {
		scanner := scanner_
		run.Do(func() error {
			units2, err := Scan(scanner, opt, treeConfig)
			if err != nil {
				cmd, newErr := scanner.Command()
				if newErr != nil {
					return fmt.Errorf("cmd error: %s", newErr)
				}
				return fmt.Errorf("scanner %v: %s", cmd.Args, err)
			}

			mu.Lock()
			defer mu.Unlock()
			units = append(units, units2...)
			return nil
		})
	}
	err := run.Wait()
	// Return error only if none of the commands succeeded.
	if len(units) == 0 {
		return nil, err
	}
	return units, nil
}