Golang Artifact.DefaultS3URL方法代碼示例

// Merges all of the individual chunks into a single object and stores it on s3.
// The log chunks are stored in the database, while the object is uploaded to s3.
func MergeLogChunks(ctx context.Context, artifact *model.Artifact, db database.Database, s3bucket *s3.Bucket) error {
	switch artifact.State {
	case model.APPEND_COMPLETE:
		// TODO: Reimplement using GorpDatabase
		// If the file is empty, don't bother creating an object on S3.
		if artifact.Size == 0 {
			artifact.State = model.CLOSED_WITHOUT_DATA
			artifact.S3URL = ""

			// Conversion between *DatabaseEror and error is tricky. If we don't do this, a nil
			// *DatabaseError can become a non-nil error.
			return db.UpdateArtifact(artifact).GetError()
		}

		// XXX Do we need to commit here or is this handled transparently?
		artifact.State = model.UPLOADING
		if err := db.UpdateArtifact(artifact); err != nil {
			return err
		}

		fileName := artifact.DefaultS3URL()

		r := newLogChunkReaderWithReadahead(artifact, db)

		if err := uploadArtifactToS3(s3bucket, fileName, artifact.Size, r); err != nil {
			return err
		}

		// XXX This is a long operation and should probably be asynchronous from the
		// actual HTTP request, and the client should poll to check when its uploaded.
		artifact.State = model.UPLOADED
		artifact.S3URL = fileName
		if err := db.UpdateArtifact(artifact); err != nil {
			return err
		}

		// From this point onwards, we will not send back any errors back to the user. If we are
		// unable to delete logchunks, we log it to Sentry instead.
		if _, err := db.DeleteLogChunksForArtifact(artifact.Id); err != nil {
			sentry.ReportError(ctx, err)
			return nil
		}

		return nil

	case model.WAITING_FOR_UPLOAD:
		fallthrough
	case model.ERROR:
		fallthrough
	case model.APPENDING:
		fallthrough
	case model.UPLOADED:
		fallthrough
	case model.UPLOADING:
		return fmt.Errorf("Artifact can only be merged when in APPEND_COMPLETE state, but state is %s", artifact.State)
	default:
		return fmt.Errorf("Illegal artifact state! State code is %d", artifact.State)
	}
}

// PutArtifact writes a streamed artifact to S3. The entire file contents are streamed directly
// through to S3. If S3 is not accessible, we don't make any attempt to buffer on disk and fail
// immediately.
func PutArtifact(ctx context.Context, artifact *model.Artifact, db database.Database, bucket *s3.Bucket, req PutArtifactReq) error {
	if artifact.State != model.WAITING_FOR_UPLOAD {
		return fmt.Errorf("Expected artifact to be in state WAITING_FOR_UPLOAD: %s", artifact.State)
	}

	// New file being inserted into DB.
	// Mark status change to UPLOADING and start uploading to S3.
	//
	// First, verify that the size of the content being uploaded matches our expected size.
	var fileSize int64
	var err error

	if req.ContentLength != "" {
		fileSize, err = strconv.ParseInt(req.ContentLength, 10, 64) // string, base, bits
		// This should never happen if a sane HTTP client is used. Nonetheless ...
		if err != nil {
			return fmt.Errorf("Invalid Content-Length specified")
		}
	} else {
		// This too should never happen if a sane HTTP client is used. Nonetheless ...
		return fmt.Errorf("Content-Length not specified")
	}

	if fileSize != artifact.Size {
		return fmt.Errorf("Content length %d does not match expected file size %d", fileSize, artifact.Size)
	}

	artifact.State = model.UPLOADING
	if err := db.UpdateArtifact(artifact); err != nil {
		return err
	}

	cleanupAndReturn := func(err error) error {
		// TODO: Is there a better way to detect and handle errors?
		// Use a channel to signify upload completion. In defer, check if the channel is empty. If
		// yes, mark error. Else ignore.
		if err != nil {
			// TODO: s/ERROR/WAITING_FOR_UPLOAD/ ?
			sentry.ReportError(ctx, err)
			artifact.State = model.ERROR
			err2 := db.UpdateArtifact(artifact)
			if err2 != nil {
				log.Printf("Error while handling error: %s", err2.Error())
			}
			return err
		}

		return nil
	}

	b := new(bytes.Buffer)
	// Note: Storing entire contents of uploaded artifact in memory can cause OOMS.
	if n, err := io.CopyN(b, req.Body, artifact.Size); err != nil {
		return cleanupAndReturn(fmt.Errorf("Error reading from request body (for artifact %s/%s, bytes (%d/%d) read): %s", artifact.BucketId, artifact.Name, n, artifact.Size, err))
	}
	fileName := artifact.DefaultS3URL()

	if err := uploadArtifactToS3(bucket, fileName, artifact.Size, bytes.NewReader(b.Bytes())); err != nil {
		return cleanupAndReturn(err)
	}

	artifact.State = model.UPLOADED
	artifact.S3URL = fileName
	if err := db.UpdateArtifact(artifact); err != nil {
		return err
	}
	return nil
}

func PutArtifact(artifact *model.Artifact, db database.Database, bucket *s3.Bucket, req PutArtifactReq) error {
	if artifact.State != model.WAITING_FOR_UPLOAD {
		return fmt.Errorf("Expected artifact to be in state WAITING_FOR_UPLOAD: %s", artifact.State)
	}

	// New file being inserted into DB.
	// Mark status change to UPLOADING and start uploading to S3.
	//
	// First, verify that the size of the content being uploaded matches our expected size.
	var fileSize int64
	var err error

	if req.ContentLength != "" {
		fileSize, err = strconv.ParseInt(req.ContentLength, 10, 64) // string, base, bits
		// This should never happen if a sane HTTP client is used. Nonetheless ...
		if err != nil {
			return fmt.Errorf("Invalid Content-Length specified")
		}
	} else {
		// This too should never happen if a sane HTTP client is used. Nonetheless ...
		return fmt.Errorf("Content-Length not specified")
	}

	if fileSize != artifact.Size {
		return fmt.Errorf("Content length %d does not match expected file size %d", fileSize, artifact.Size)
	}

	// XXX Do we need to commit here or is this handled transparently?
	artifact.State = model.UPLOADING
	if err := db.UpdateArtifact(artifact); err != nil {
		return err
	}

	cleanupAndReturn := func(err error) error {
		// TODO: Is there a better way to detect and handle errors?
		// Use a channel to signify upload completion. In defer, check if the channel is empty. If
		// yes, mark error. Else ignore.
		if err != nil {
			// TODO: s/ERROR/WAITING_FOR_UPLOAD/ ?
			log.Printf("Error uploading to S3: %s\n", err)
			artifact.State = model.ERROR
			err2 := db.UpdateArtifact(artifact)
			if err2 != nil {
				log.Printf("Error while handling error: %s", err2.Error())
			}
			return err
		}

		return nil
	}

	fileName := artifact.DefaultS3URL()
	if err := bucket.PutReader(fileName, req.Body, artifact.Size, "binary/octet-stream", s3.PublicRead); err != nil {
		return cleanupAndReturn(fmt.Errorf("Error uploading to S3: %s", err))
	}

	artifact.State = model.UPLOADED
	artifact.S3URL = fileName
	if err := db.UpdateArtifact(artifact); err != nil {
		return err
	}
	return nil
}

// Merges all of the individual chunks into a single object and stores it on s3.
// The log chunks are stored in the database, while the object is uploaded to s3.
func MergeLogChunks(artifact *model.Artifact, db database.Database, s3bucket *s3.Bucket) error {
	switch artifact.State {
	case model.APPEND_COMPLETE:
		// TODO: Reimplement using GorpDatabase
		// If the file is empty, don't bother creating an object on S3.
		if artifact.Size == 0 {
			artifact.State = model.CLOSED_WITHOUT_DATA
			artifact.S3URL = ""

			// Conversion between *DatabaseEror and error is tricky. If we don't do this, a nil
			// *DatabaseError can become a non-nil error.
			return db.UpdateArtifact(artifact).GetError()
		}

		// XXX Do we need to commit here or is this handled transparently?
		artifact.State = model.UPLOADING
		if err := db.UpdateArtifact(artifact); err != nil {
			return err
		}

		logChunks, err := db.ListLogChunksInArtifact(artifact.Id)
		if err != nil {
			return err
		}

		r, w := io.Pipe()
		errChan := make(chan error)
		uploadCompleteChan := make(chan bool)
		fileName := artifact.DefaultS3URL()

		// Asynchronously upload the object to s3 while reading from the r, w
		// pipe. Thus anything written to "w" will be sent to S3.
		go func() {
			defer close(errChan)
			defer close(uploadCompleteChan)
			defer r.Close()
			if err := s3bucket.PutReader(fileName, r, artifact.Size, "binary/octet-stream", s3.PublicRead); err != nil {
				errChan <- fmt.Errorf("Error uploading to S3: %s", err)
				return
			}

			uploadCompleteChan <- true
		}()

		for _, logChunk := range logChunks {
			w.Write([]byte(logChunk.Content))
		}

		w.Close()

		// Wait either for S3 upload to complete or for it to fail with an error.
		// XXX This is a long operation and should probably be asynchronous from the
		// actual HTTP request, and the client should poll to check when its uploaded.
		select {
		case _ = <-uploadCompleteChan:
			artifact.State = model.UPLOADED
			artifact.S3URL = fileName
			if err := db.UpdateArtifact(artifact); err != nil {
				return err
			}

			// From this point onwards, we will not send back any errors back to the user. If we are
			// unable to delete logchunks, we log it to Sentry instead.
			if n, err := db.DeleteLogChunksForArtifact(artifact.Id); err != nil {
				// TODO: Send this error to Sentry
				log.Printf("Error deleting logchunks for artifact %d: %v\n", artifact.Id, err)
				return nil
			} else if n != int64(len(logChunks)) {
				// TODO: Send this error to Sentry
				log.Printf("Mismatch in number of logchunks while deleting logchunks for artifact %d:"+
					"Expected: %d Actual: %d\n", artifact.Id, len(logChunks), n)
			}

			return nil
		case err := <-errChan:
			return err
		}

	case model.WAITING_FOR_UPLOAD:
		fallthrough
	case model.ERROR:
		fallthrough
	case model.APPENDING:
		fallthrough
	case model.UPLOADED:
		fallthrough
	case model.UPLOADING:
		return fmt.Errorf("Artifact can only be merged when in APPEND_COMPLETE state, but state is %s", artifact.State)
	default:
		return fmt.Errorf("Illegal artifact state! State code is %d", artifact.State)
	}
}