| // Copyright 2017 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| // Package backend contains the necessary functions to classify a license. |
| package backend |
| |
| import ( |
| "context" |
| "fmt" |
| "io/ioutil" |
| "log" |
| "sync" |
| "time" |
| |
| //gc "google3/devtools/compliance/common/licenseclassifier/classifier" |
| |
| "github.com/google/licenseclassifier/tools/identify_license/results/v2" |
| classifier "github.com/google/licenseclassifier/v2" |
| "github.com/google/licenseclassifier/v2/assets" |
| ) |
| |
| // ClassifierInterface is the interface each backend must implement. |
| type ClassifierInterface interface { |
| Close() |
| SetTraceConfiguration(tc *classifier.TraceConfiguration) |
| ClassifyLicenses(numTasks int, filenames []string, headers bool) []error |
| ClassifyLicensesWithContext(ctx context.Context, numTasks int, filenames []string, headers bool) []error |
| GetResults() results.LicenseTypes |
| } |
| |
| // ClassifierBackend is an object that handles classifying a license. |
| type ClassifierBackend struct { |
| results results.LicenseTypes |
| mu sync.Mutex |
| classifier *classifier.Classifier |
| } |
| |
| // New creates a new backend working on the local filesystem. |
| func New() (*ClassifierBackend, error) { |
| _, err := assets.ReadLicenseDir() |
| if err != nil { |
| return nil, err |
| } |
| lc, err := assets.DefaultClassifier() |
| if err != nil { |
| return nil, err |
| } |
| return &ClassifierBackend{classifier: lc}, nil |
| } |
| |
| // Close does nothing here since there's nothing to close. |
| func (b *ClassifierBackend) Close() { |
| } |
| |
| // SetTraceConfiguration injects the supplied trace configuration |
| func (b *ClassifierBackend) SetTraceConfiguration(tc *classifier.TraceConfiguration) { |
| //b.classifier.SetTraceConfiguration((*gc.TraceConfiguration)(tc)) |
| } |
| |
| // ClassifyLicenses runs the license classifier over the given file. |
| func (b *ClassifierBackend) ClassifyLicenses(numTasks int, filenames []string, headers bool) (errors []error) { |
| // Create a pool from which tasks can later be started. We use a pool because the OS limits |
| // the number of files that can be open at any one time. |
| task := make(chan bool, numTasks) |
| for i := 0; i < numTasks; i++ { |
| task <- true |
| } |
| |
| errs := make(chan error, len(filenames)) |
| |
| var wg sync.WaitGroup |
| analyze := func(filename string) { |
| defer func() { |
| wg.Done() |
| task <- true |
| }() |
| if err := b.classifyLicense(filename, headers); err != nil { |
| errs <- err |
| } |
| } |
| |
| for _, filename := range filenames { |
| wg.Add(1) |
| <-task |
| go analyze(filename) |
| } |
| go func() { |
| wg.Wait() |
| close(task) |
| close(errs) |
| }() |
| |
| for err := range errs { |
| errors = append(errors, err) |
| } |
| return errors |
| } |
| |
| // ClassifyLicensesWithContext runs the license classifier over the given file; ensure that it will respect the timeout in the provided context. |
| func (b *ClassifierBackend) ClassifyLicensesWithContext(ctx context.Context, numTasks int, filenames []string, headers bool) (errors []error) { |
| done := make(chan bool) |
| go func() { |
| errors = b.ClassifyLicenses(numTasks, filenames, headers) |
| done <- true |
| }() |
| select { |
| case <-ctx.Done(): |
| err := ctx.Err() |
| errors = append(errors, err) |
| return errors |
| case <-done: |
| return errors |
| } |
| } |
| |
| // classifyLicense is called by a Go-function to perform the actual |
| // classification of a license. |
| func (b *ClassifierBackend) classifyLicense(filename string, headers bool) error { |
| contents, err := ioutil.ReadFile(filename) |
| if err != nil { |
| return fmt.Errorf("unable to read %q: %v", filename, err) |
| } |
| |
| matchLoop := func(contents []byte) { |
| for _, m := range b.classifier.Match(contents).Matches { |
| // If not looking for headers, skip them |
| if !headers && m.MatchType == "Header" { |
| continue |
| } |
| |
| b.mu.Lock() |
| b.results = append(b.results, &results.LicenseType{ |
| Filename: filename, |
| MatchType: m.MatchType, |
| Name: m.Name, |
| Variant: m.Variant, |
| Confidence: m.Confidence, |
| StartLine: m.StartLine, |
| EndLine: m.EndLine, |
| }) |
| b.mu.Unlock() |
| } |
| } |
| |
| log.Printf("Classifying license(s): %s", filename) |
| start := time.Now() |
| matchLoop(contents) |
| log.Printf("Finished Classifying License %q: %v", filename, time.Since(start)) |
| return nil |
| } |
| |
| // GetResults returns the results of the classifications. |
| func (b *ClassifierBackend) GetResults() results.LicenseTypes { |
| return b.results |
| } |