Rework the Backblaze B2 backend

* All APIs include UploadFile are done via the call() function
* New retry mechanism limiting the maximum backoff each time to 1 minute
* Add an env var DUPLICACY_B2_RETRIES to specify the number of retries
* Handle special/unicode characters in repositor ids
* Allow a directory in a bucket to be used as the storage destination

src/duplicacy_b2client.go

@@ -5,19 +5,22 @@
 package duplicacy
 
 import (
-	"bytes"
-	"crypto/sha1"
-	"encoding/base64"
-	"encoding/hex"
-	"encoding/json"
-	"fmt"
 	"io"
-	"io/ioutil"
-	"math/rand"
-	"net/http"
+	"os"
+	"fmt"
+	"bytes"
+	"time"
+	"sync"
 	"strconv"
 	"strings"
-	"time"
+	"net/url"
+	"net/http"
+	"math/rand"
+	"io/ioutil"
+	"crypto/sha1"
+	"encoding/hex"
+	"encoding/json"
+	"encoding/base64"
 )
 
 type B2Error struct {
@@ -39,67 +42,112 @@ var B2AuthorizationURL = "https://api.backblazeb2.com/b2api/v1/b2_authorize_acco
 
 type B2Client struct {
 	HTTPClient         *http.Client
+
 	AccountID          string
 	ApplicationKeyID   string
 	ApplicationKey     string
+	BucketName         string
+	BucketID           string
+	StorageDir         string
+
+	Lock               sync.Mutex
 	AuthorizationToken string
 	APIURL             string
 	DownloadURL        string
-	BucketName         string
-	BucketID           string
+	IsAuthorized       bool
 
-	UploadURL   string
-	UploadToken string
+	UploadURLs         []string
+	UploadTokens       []string
 
-	TestMode bool
+	Threads            int
+	MaximumRetries     int
+	TestMode           bool
 }
 
-func NewB2Client(applicationKeyID string, applicationKey string) *B2Client {
+// URL encode the given path but keep the slashes intact
+func B2Escape(path string) string {
+	var components []string
+	for _, c := range strings.Split(path, "/") {
+		components = append(components, url.QueryEscape(c))
+	}
+	return strings.Join(components, "/")
+}
+
+func NewB2Client(applicationKeyID string, applicationKey string, storageDir string, threads int) *B2Client {
+
+	for storageDir != "" && storageDir[0] == '/' {
+		storageDir = storageDir[1:]
+	}
+
+	if storageDir != "" && storageDir[len(storageDir) - 1] != '/' {
+		storageDir += "/"
+	}
+
+	maximumRetries := 10
+	if value, found := os.LookupEnv("DUPLICACY_B2_RETRIES"); found && value != "" {
+		maximumRetries, _ = strconv.Atoi(value)
+		LOG_INFO("B2_RETRIES", "Setting maximum retries for B2 to %d", maximumRetries)
+	}
+
 	client := &B2Client{
 		HTTPClient:       http.DefaultClient,
 		ApplicationKeyID: applicationKeyID,
 		ApplicationKey:   applicationKey,
+		StorageDir:       storageDir,
+		UploadURLs:       make([]string, threads),
+		UploadTokens:     make([]string, threads),
+		Threads:          threads,
+		MaximumRetries:   maximumRetries,
 	}
 	return client
 }
 
-func (client *B2Client) retry(backoff int, response *http.Response) int {
+func (client *B2Client) getAPIURL() string {
+	client.Lock.Lock()
+	defer client.Lock.Unlock()
+	return client.APIURL
+}
+
+func (client *B2Client) getDownloadURL() string {
+	client.Lock.Lock()
+	defer client.Lock.Unlock()
+	return client.DownloadURL
+}
+
+func (client *B2Client) retry(retries int, response *http.Response) int {
 	if response != nil {
 		if backoffList, found := response.Header["Retry-After"]; found && len(backoffList) > 0 {
 			retryAfter, _ := strconv.Atoi(backoffList[0])
 			if retryAfter >= 1 {
 				time.Sleep(time.Duration(retryAfter) * time.Second)
-				return 0
+				return 1
 			}
 		}
 	}
-	if backoff == 0 {
-		backoff = 1
-	} else {
-		backoff *= 2
+
+	if retries >= client.MaximumRetries + 1 {
+		return 0
 	}
-	time.Sleep(time.Duration(backoff) * time.Second)
-	return backoff
+	retries++
+	delay := 1 << uint(retries)
+	if delay > 64 {
+		delay = 64
+	}
+	delayInSeconds := (rand.Float32() + 1.0) * float32(delay) / 2.0
+
+	time.Sleep(time.Duration(delayInSeconds) * time.Second)
+	return retries
 }
 
-func (client *B2Client) call(url string, method string, requestHeaders map[string]string, input interface{}) (io.ReadCloser, http.Header, int64, error) {
-
-	switch method {
-	case http.MethodGet:
-		break
-	case http.MethodHead:
-		break
-	case http.MethodPost:
-		break
-	default:
-		return nil, nil, 0, fmt.Errorf("unhandled http request method: " + method)
-	}
+func (client *B2Client) call(threadIndex int, requestURL string, method string, requestHeaders map[string]string, input interface{}) (
+	                         io.ReadCloser, http.Header, int64, error) {
 
 	var response *http.Response
 
-	backoff := 0
-	for i := 0; i < 8; i++ {
-		var inputReader *bytes.Reader
+	retries := 0
+	for {
+		var inputReader io.Reader
+		isUpload := false
 
 		switch input.(type) {
 		default:
@@ -108,21 +156,43 @@ func (client *B2Client) call(url string, method string, requestHeaders map[strin
 				return nil, nil, 0, err
 			}
 			inputReader = bytes.NewReader(jsonInput)
-		case []byte:
-			inputReader = bytes.NewReader(input.([]byte))
 		case int:
 			inputReader = bytes.NewReader([]byte(""))
+		case []byte:
+			isUpload = true
+			inputReader = bytes.NewReader(input.([]byte))
+		case *RateLimitedReader:
+			isUpload = true
+			rateLimitedReader := input.(*RateLimitedReader)
+			rateLimitedReader.Reset()
+			inputReader = rateLimitedReader
 		}
 
-		request, err := http.NewRequest(method, url, inputReader)
+
+		if isUpload {
+			if client.UploadURLs[threadIndex] == "" || client.UploadTokens[threadIndex] == "" {
+				err := client.getUploadURL(threadIndex)
+				if err != nil {
+					return nil, nil, 0, err
+				}
+			}
+			requestURL = client.UploadURLs[threadIndex]
+		}
+
+		request, err := http.NewRequest(method, requestURL, inputReader)
 		if err != nil {
 			return nil, nil, 0, err
 		}
 
-		if url == B2AuthorizationURL {
+		if requestURL == B2AuthorizationURL {
 			request.Header.Set("Authorization", "Basic "+base64.StdEncoding.EncodeToString([]byte(client.ApplicationKeyID+":"+client.ApplicationKey)))
+		} else if isUpload {
+			request.ContentLength, _ = strconv.ParseInt(requestHeaders["Content-Length"], 10, 64)
+			request.Header.Set("Authorization", client.UploadTokens[threadIndex])
 		} else {
+			client.Lock.Lock()
 			request.Header.Set("Authorization", client.AuthorizationToken)
+			client.Lock.Unlock()
 		}
 
 		if requestHeaders != nil {
@@ -133,7 +203,9 @@ func (client *B2Client) call(url string, method string, requestHeaders map[strin
 
 		if client.TestMode {
 			r := rand.Float32()
-			if r < 0.5 {
+			if r < 0.5 && isUpload {
+				request.Header.Set("X-Bz-Test-Mode", "fail_some_uploads")
+			} else if r < 0.75 {
 				request.Header.Set("X-Bz-Test-Mode", "expire_some_account_authorization_tokens")
 			} else {
 				request.Header.Set("X-Bz-Test-Mode", "force_cap_exceeded")
@@ -142,27 +214,46 @@ func (client *B2Client) call(url string, method string, requestHeaders map[strin
 
 		response, err = client.HTTPClient.Do(request)
 		if err != nil {
-			if url != B2AuthorizationURL {
-				LOG_DEBUG("BACKBLAZE_CALL", "URL request '%s' returned an error: %v", url, err)
-				backoff = client.retry(backoff, response)
-				continue
+
+			// Don't retry when the first authorization request fails
+			if requestURL == B2AuthorizationURL && !client.IsAuthorized {
+				return nil, nil, 0, err
 			}
-			return nil, nil, 0, err
+
+			LOG_TRACE("BACKBLAZE_CALL", "[%d] URL request '%s' returned an error: %v", threadIndex, requestURL, err)
+
+			retries = client.retry(retries, response)
+			if retries <= 0 {
+				return nil, nil, 0, err
+			}
+
+			// Clear the upload url to requrest a new one on retry
+			if isUpload {
+				client.UploadURLs[threadIndex] = ""
+				client.UploadTokens[threadIndex] = ""
+			}
+			continue
+
 		}
 
 		if response.StatusCode < 300 {
 			return response.Body, response.Header, response.ContentLength, nil
 		}
 
-		LOG_DEBUG("BACKBLAZE_CALL", "URL request '%s %s' returned status code %d", method, url, response.StatusCode)
+		e := &B2Error{}
+		if err := json.NewDecoder(response.Body).Decode(e); err != nil {
+			LOG_TRACE("BACKBLAZE_CALL", "[%d] URL request '%s %s' returned status code %d", threadIndex, method, requestURL, response.StatusCode)
+		} else {
+			LOG_TRACE("BACKBLAZE_CALL", "[%d] URL request '%s %s' returned %d %s", threadIndex, method, requestURL, response.StatusCode, e.Message)
+		}
 
-		io.Copy(ioutil.Discard, response.Body)
 		response.Body.Close()
+
 		if response.StatusCode == 401 {
-			if url == B2AuthorizationURL {
+			if requestURL == B2AuthorizationURL {
 				return nil, nil, 0, fmt.Errorf("Authorization failure")
 			}
-			client.AuthorizeAccount()
+			client.AuthorizeAccount(threadIndex)
 			continue
 		} else if response.StatusCode == 403 {
 			if !client.TestMode {
@@ -176,32 +267,21 @@ func (client *B2Client) call(url string, method string, requestHeaders map[strin
 		} else if response.StatusCode == 416 {
 			if http.MethodHead == method {
 				// 416 Requested Range Not Satisfiable
-				return nil, nil, 0, fmt.Errorf("URL request '%s' returned status code %d", url, response.StatusCode)
+				return nil, nil, 0, fmt.Errorf("URL request '%s' returned %d %s", requestURL, response.StatusCode, e.Message)
 			}
-		} else if response.StatusCode == 429 || response.StatusCode == 408 {
-			backoff = client.retry(backoff, response)
-			continue
-		} else if response.StatusCode >= 500 && response.StatusCode <= 599 {
-			backoff = client.retry(backoff, response)
-			continue
-		} else {
-			LOG_INFO("BACKBLAZE_CALL", "URL request '%s' returned status code %d", url, response.StatusCode)
-			backoff = client.retry(backoff, response)
-			continue
 		}
 
-		defer response.Body.Close()
-
-		e := &B2Error{}
-
-		if err := json.NewDecoder(response.Body).Decode(e); err != nil {
-			return nil, nil, 0, err
+		retries = client.retry(retries, response)
+		if retries <= 0 {
+			return nil, nil, 0, fmt.Errorf("URL request '%s' returned %d %s", requestURL, response.StatusCode, e.Message)
 		}
 
-		return nil, nil, 0, e
+		if isUpload {
+			client.UploadURLs[threadIndex] = ""
+			client.UploadTokens[threadIndex] = ""
+		}
 	}
 
-	return nil, nil, 0, fmt.Errorf("Maximum backoff reached")
 }
 
 type B2AuthorizeAccountOutput struct {
@@ -211,9 +291,11 @@ type B2AuthorizeAccountOutput struct {
 	DownloadURL        string
 }
 
-func (client *B2Client) AuthorizeAccount() (err error) {
+func (client *B2Client) AuthorizeAccount(threadIndex int) (err error) {
+	client.Lock.Lock()
+	defer client.Lock.Unlock()
 
-	readCloser, _, _, err := client.call(B2AuthorizationURL, http.MethodPost, nil, make(map[string]string))
+	readCloser, _, _, err := client.call(threadIndex, B2AuthorizationURL, http.MethodPost, nil, make(map[string]string))
 	if err != nil {
 		return err
 	}
@@ -233,6 +315,7 @@ func (client *B2Client) AuthorizeAccount() (err error) {
 	client.AuthorizationToken = output.AuthorizationToken
 	client.APIURL = output.APIURL
 	client.DownloadURL = output.DownloadURL
+	client.IsAuthorized = true
 
 	return nil
 }
@@ -249,9 +332,9 @@ func (client *B2Client) FindBucket(bucketName string) (err error) {
 	input := make(map[string]string)
 	input["accountId"] = client.AccountID
 
-	url := client.APIURL + "/b2api/v1/b2_list_buckets"
+	url := client.getAPIURL() + "/b2api/v1/b2_list_buckets"
 
-	readCloser, _, _, err := client.call(url, http.MethodPost, nil, input)
+	readCloser, _, _, err := client.call(0, url, http.MethodPost, nil, input)
 	if err != nil {
 		return err
 	}
@@ -293,7 +376,7 @@ type B2ListFileNamesOutput struct {
 	NextFileId   string
 }
 
-func (client *B2Client) ListFileNames(startFileName string, singleFile bool, includeVersions bool) (files []*B2Entry, err error) {
+func (client *B2Client) ListFileNames(threadIndex int, startFileName string, singleFile bool, includeVersions bool) (files []*B2Entry, err error) {
 
 	maxFileCount := 1000
 	if singleFile {
@@ -311,20 +394,21 @@ func (client *B2Client) ListFileNames(startFileName string, singleFile bool, inc
 
 	input := make(map[string]interface{})
 	input["bucketId"] = client.BucketID
-	input["startFileName"] = startFileName
+	input["startFileName"] = client.StorageDir + startFileName
 	input["maxFileCount"] = maxFileCount
+	input["prefix"] = client.StorageDir
 
 	for {
-		url := client.APIURL + "/b2api/v1/b2_list_file_names"
+		url := client.getAPIURL() + "/b2api/v1/b2_list_file_names"
 		requestHeaders := map[string]string{}
 		requestMethod := http.MethodPost
 		var requestInput interface{}
 		requestInput = input
 		if includeVersions {
-			url = client.APIURL + "/b2api/v1/b2_list_file_versions"
+			url = client.getAPIURL() + "/b2api/v1/b2_list_file_versions"
 		} else if singleFile {
 			// handle a single file with no versions as a special case to download the last byte of the file
-			url = client.DownloadURL + "/file/" + client.BucketName + "/" + startFileName
+			url = client.getDownloadURL() + "/file/" + client.BucketName + "/" + B2Escape(client.StorageDir + startFileName)
 			// requesting byte -1 works for empty files where 0-0 fails with a 416 error
 			requestHeaders["Range"] = "bytes=-1"
 			// HEAD request
@@ -334,7 +418,7 @@ func (client *B2Client) ListFileNames(startFileName string, singleFile bool, inc
 		var readCloser io.ReadCloser
 		var responseHeader http.Header
 		var err error
-		readCloser, responseHeader, _, err = client.call(url, requestMethod, requestHeaders, requestInput)
+		readCloser, responseHeader, _, err = client.call(threadIndex, url, requestMethod, requestHeaders, requestInput)
 		if err != nil {
 			return nil, err
 		}
@@ -347,7 +431,7 @@ func (client *B2Client) ListFileNames(startFileName string, singleFile bool, inc
 
 		if singleFile && !includeVersions {
 			if responseHeader == nil {
-				LOG_DEBUG("BACKBLAZE_LIST", "b2_download_file_by_name did not return headers")
+				LOG_DEBUG("BACKBLAZE_LIST", "%s did not return headers", url)
 				return []*B2Entry{}, nil
 			}
 			requiredHeaders := []string{
@@ -361,7 +445,7 @@ func (client *B2Client) ListFileNames(startFileName string, singleFile bool, inc
 				}
 			}
 			if len(missingKeys) > 0 {
-				return nil, fmt.Errorf("b2_download_file_by_name missing headers: %s", missingKeys)
+				return nil, fmt.Errorf("%s missing headers: %s", url, missingKeys)
 			}
 			// construct the B2Entry from the response headers of the download request
 			fileID := responseHeader.Get("x-bz-file-id")
@@ -378,14 +462,14 @@ func (client *B2Client) ListFileNames(startFileName string, singleFile bool, inc
 				// this should only execute if the requested file is empty and the range request didn't result in a Content-Range header
 				fileSize, _ = strconv.ParseInt(lengthString, 0, 64)
 				if fileSize != 0 {
-					return nil, fmt.Errorf("b2_download_file_by_name returned non-zero file length")
+					return nil, fmt.Errorf("%s returned non-zero file length", url)
 				}
 			} else {
-				return nil, fmt.Errorf("could not parse b2_download_file_by_name headers")
+				return nil, fmt.Errorf("could not parse headers returned by %s", url)
 			}
 			fileUploadTimestamp, _ := strconv.ParseInt(responseHeader.Get("X-Bz-Upload-Timestamp"), 0, 64)
 
-			return []*B2Entry{{fileID, fileName, fileAction, fileSize, fileUploadTimestamp}}, nil
+			return []*B2Entry{{fileID, fileName[len(client.StorageDir):], fileAction, fileSize, fileUploadTimestamp}}, nil
 		}
 
 		if err = json.NewDecoder(readCloser).Decode(&output); err != nil {
@@ -394,31 +478,27 @@ func (client *B2Client) ListFileNames(startFileName string, singleFile bool, inc
 
 		ioutil.ReadAll(readCloser)
 
-		if startFileName == "" {
-			files = append(files, output.Files...)
-		} else {
-			for _, file := range output.Files {
-				if singleFile {
-					if file.FileName == startFileName {
-						files = append(files, file)
-						if !includeVersions {
-							output.NextFileName = ""
-							break
-						}
-					} else {
+		for _, file := range output.Files {
+			file.FileName = file.FileName[len(client.StorageDir):]
+			if singleFile {
+				if file.FileName == startFileName {
+					files = append(files, file)
+					if !includeVersions {
 						output.NextFileName = ""
 						break
 					}
 				} else {
-					if strings.HasPrefix(file.FileName, startFileName) {
-						files = append(files, file)
-					} else {
-						output.NextFileName = ""
-						break
-					}
+					output.NextFileName = ""
+					break
+				}
+			} else {
+				if strings.HasPrefix(file.FileName, startFileName) {
+					files = append(files, file)
+				} else {
+					output.NextFileName = ""
+					break
 				}
 			}
-
 		}
 
 		if len(output.NextFileName) == 0 {
@@ -434,14 +514,14 @@ func (client *B2Client) ListFileNames(startFileName string, singleFile bool, inc
 	return files, nil
 }
 
-func (client *B2Client) DeleteFile(fileName string, fileID string) (err error) {
+func (client *B2Client) DeleteFile(threadIndex int, fileName string, fileID string) (err error) {
 
 	input := make(map[string]string)
-	input["fileName"] = fileName
+	input["fileName"] = client.StorageDir + fileName
 	input["fileId"] = fileID
 
-	url := client.APIURL + "/b2api/v1/b2_delete_file_version"
-	readCloser, _, _, err := client.call(url, http.MethodPost, make(map[string]string), input)
+	url := client.getAPIURL() + "/b2api/v1/b2_delete_file_version"
+	readCloser, _, _, err := client.call(threadIndex, url, http.MethodPost, make(map[string]string), input)
 	if err != nil {
 		return err
 	}
@@ -454,14 +534,14 @@ type B2HideFileOutput struct {
 	FileID string
 }
 
-func (client *B2Client) HideFile(fileName string) (fileID string, err error) {
+func (client *B2Client) HideFile(threadIndex int, fileName string) (fileID string, err error) {
 
 	input := make(map[string]string)
 	input["bucketId"] = client.BucketID
-	input["fileName"] = fileName
+	input["fileName"] = client.StorageDir + fileName
 
-	url := client.APIURL + "/b2api/v1/b2_hide_file"
-	readCloser, _, _, err := client.call(url, http.MethodPost, make(map[string]string), input)
+	url := client.getAPIURL() + "/b2api/v1/b2_hide_file"
+	readCloser, _, _, err := client.call(threadIndex, url, http.MethodPost, make(map[string]string), input)
 	if err != nil {
 		return "", err
 	}
@@ -478,11 +558,11 @@ func (client *B2Client) HideFile(fileName string) (fileID string, err error) {
 	return output.FileID, nil
 }
 
-func (client *B2Client) DownloadFile(filePath string) (io.ReadCloser, int64, error) {
+func (client *B2Client) DownloadFile(threadIndex int, filePath string) (io.ReadCloser, int64, error) {
 
-	url := client.DownloadURL + "/file/" + client.BucketName + "/" + filePath
+	url := client.getDownloadURL() + "/file/" + client.BucketName + "/" + B2Escape(client.StorageDir + filePath)
 
-	readCloser, _, len, err := client.call(url, http.MethodGet, make(map[string]string), 0)
+	readCloser, _, len, err := client.call(threadIndex, url, http.MethodGet, make(map[string]string), 0)
 	return readCloser, len, err
 }
 
@@ -492,12 +572,12 @@ type B2GetUploadArgumentOutput struct {
 	AuthorizationToken string
 }
 
-func (client *B2Client) getUploadURL() error {
+func (client *B2Client) getUploadURL(threadIndex int) error {
 	input := make(map[string]string)
 	input["bucketId"] = client.BucketID
 
-	url := client.APIURL + "/b2api/v1/b2_get_upload_url"
-	readCloser, _, _, err := client.call(url, http.MethodPost, make(map[string]string), input)
+	url := client.getAPIURL() + "/b2api/v1/b2_get_upload_url"
+	readCloser, _, _, err := client.call(threadIndex, url, http.MethodPost, make(map[string]string), input)
 	if err != nil {
 		return err
 	}
@@ -510,96 +590,29 @@ func (client *B2Client) getUploadURL() error {
 		return err
 	}
 
-	client.UploadURL = output.UploadURL
-	client.UploadToken = output.AuthorizationToken
+	client.UploadURLs[threadIndex] = output.UploadURL
+	client.UploadTokens[threadIndex] = output.AuthorizationToken
 
 	return nil
 }
 
-func (client *B2Client) UploadFile(filePath string, content []byte, rateLimit int) (err error) {
+func (client *B2Client) UploadFile(threadIndex int, filePath string, content []byte, rateLimit int) (err error) {
 
 	hasher := sha1.New()
 	hasher.Write(content)
 	hash := hex.EncodeToString(hasher.Sum(nil))
 
 	headers := make(map[string]string)
-	headers["X-Bz-File-Name"] = filePath
+	headers["X-Bz-File-Name"] = B2Escape(client.StorageDir + filePath)
+	headers["Content-Length"] = fmt.Sprintf("%d", len(content))
 	headers["Content-Type"] = "application/octet-stream"
 	headers["X-Bz-Content-Sha1"] = hash
 
-	var response *http.Response
-
-	backoff := 0
-	for i := 0; i < 8; i++ {
-
-		if client.UploadURL == "" || client.UploadToken == "" {
-			err = client.getUploadURL()
-			if err != nil {
-				return err
-			}
-		}
-
-		request, err := http.NewRequest("POST", client.UploadURL, CreateRateLimitedReader(content, rateLimit))
-		if err != nil {
-			return err
-		}
-		request.ContentLength = int64(len(content))
-
-		request.Header.Set("Authorization", client.UploadToken)
-		request.Header.Set("X-Bz-File-Name", filePath)
-		request.Header.Set("Content-Type", "application/octet-stream")
-		request.Header.Set("X-Bz-Content-Sha1", hash)
-
-		for key, value := range headers {
-			request.Header.Set(key, value)
-		}
-
-		if client.TestMode {
-			r := rand.Float32()
-			if r < 0.8 {
-				request.Header.Set("X-Bz-Test-Mode", "fail_some_uploads")
-			} else if r < 0.9 {
-				request.Header.Set("X-Bz-Test-Mode", "expire_some_account_authorization_tokens")
-			} else {
-				request.Header.Set("X-Bz-Test-Mode", "force_cap_exceeded")
-			}
-		}
-
-		response, err = client.HTTPClient.Do(request)
-		if err != nil {
-			LOG_DEBUG("BACKBLAZE_UPLOAD", "URL request '%s' returned an error: %v", client.UploadURL, err)
-			backoff = client.retry(backoff, response)
-			client.UploadURL = ""
-			client.UploadToken = ""
-			continue
-		}
-
-		io.Copy(ioutil.Discard, response.Body)
-		response.Body.Close()
-
-		if response.StatusCode < 300 {
-			return nil
-		}
-
-		LOG_DEBUG("BACKBLAZE_UPLOAD", "URL request '%s' returned status code %d", client.UploadURL, response.StatusCode)
-
-		if response.StatusCode == 401 {
-			LOG_INFO("BACKBLAZE_UPLOAD", "Re-authorization required")
-			client.UploadURL = ""
-			client.UploadToken = ""
-			continue
-		} else if response.StatusCode == 403 {
-			if !client.TestMode {
-				return fmt.Errorf("B2 cap exceeded")
-			}
-			continue
-		} else {
-			LOG_INFO("BACKBLAZE_UPLOAD", "URL request '%s' returned status code %d", client.UploadURL, response.StatusCode)
-			backoff = client.retry(backoff, response)
-			client.UploadURL = ""
-			client.UploadToken = ""
-		}
+	readCloser, _, _, err := client.call(threadIndex, "", http.MethodPost, headers, CreateRateLimitedReader(content, rateLimit))
+	if err != nil {
+		return err
 	}
 
-	return fmt.Errorf("Maximum backoff reached")
+	readCloser.Close()
+	return nil
 }

src/duplicacy_b2client_test.go

@@ -37,7 +37,7 @@ func createB2ClientForTest(t *testing.T) (*B2Client, string) {
 		return nil, ""
 	}
 
-	return NewB2Client(b2["account"], b2["key"]), b2["bucket"]
+	return NewB2Client(b2["account"], b2["key"], b2["directory"], 1), b2["bucket"]
 
 }
 
@@ -50,7 +50,7 @@ func TestB2Client(t *testing.T) {
 
 	b2Client.TestMode = true
 
-	err := b2Client.AuthorizeAccount()
+	err := b2Client.AuthorizeAccount(0)
 	if err != nil {
 		t.Errorf("Failed to authorize the b2 account: %v", err)
 		return
@@ -64,14 +64,14 @@ func TestB2Client(t *testing.T) {
 
 	testDirectory := "b2client_test/"
 
-	files, err := b2Client.ListFileNames(testDirectory, false, false)
+	files, err := b2Client.ListFileNames(0, testDirectory, false, false)
 	if err != nil {
 		t.Errorf("Failed to list files: %v", err)
 		return
 	}
 
 	for _, file := range files {
-		err = b2Client.DeleteFile(file.FileName, file.FileID)
+		err = b2Client.DeleteFile(0, file.FileName, file.FileID)
 		if err != nil {
 			t.Errorf("Failed to delete file '%s': %v", file.FileName, err)
 		}
@@ -90,14 +90,14 @@ func TestB2Client(t *testing.T) {
 		hash := sha256.Sum256(content)
 		name := hex.EncodeToString(hash[:])
 
-		err = b2Client.UploadFile(testDirectory+name, content, 100)
+		err = b2Client.UploadFile(0, testDirectory+name, content, 100)
 		if err != nil {
 			t.Errorf("Error uploading file '%s': %v", name, err)
 			return
 		}
 	}
 
-	files, err = b2Client.ListFileNames(testDirectory, false, false)
+	files, err = b2Client.ListFileNames(0, testDirectory, false, false)
 	if err != nil {
 		t.Errorf("Failed to list files: %v", err)
 		return
@@ -105,7 +105,7 @@ func TestB2Client(t *testing.T) {
 
 	for _, file := range files {
 
-		readCloser, _, err := b2Client.DownloadFile(file.FileName)
+		readCloser, _, err := b2Client.DownloadFile(0, file.FileName)
 		if err != nil {
 			t.Errorf("Error downloading file '%s': %v", file.FileName, err)
 			return
@@ -125,7 +125,7 @@ func TestB2Client(t *testing.T) {
 	}
 
 	for _, file := range files {
-		err = b2Client.DeleteFile(file.FileName, file.FileID)
+		err = b2Client.DeleteFile(0, file.FileName, file.FileID)
 		if err != nil {
 			t.Errorf("Failed to delete file '%s': %v", file.FileName, err)
 		}

src/duplicacy_b2storage.go

@@ -11,32 +11,26 @@ import (
 type B2Storage struct {
 	StorageBase
 
-	clients []*B2Client
+	client *B2Client
 }
 
 // CreateB2Storage creates a B2 storage object.
-func CreateB2Storage(accountID string, applicationKey string, bucket string, threads int) (storage *B2Storage, err error) {
+func CreateB2Storage(accountID string, applicationKey string, bucket string, storageDir string, threads int) (storage *B2Storage, err error) {
 
-	var clients []*B2Client
+	client := NewB2Client(accountID, applicationKey, storageDir, threads)
 
-	for i := 0; i < threads; i++ {
-		client := NewB2Client(accountID, applicationKey)
+	err = client.AuthorizeAccount(0)
+	if err != nil {
+		return nil, err
+	}
 
-		err = client.AuthorizeAccount()
-		if err != nil {
-			return nil, err
-		}
-
-		err = client.FindBucket(bucket)
-		if err != nil {
-			return nil, err
-		}
-
-		clients = append(clients, client)
+	err = client.FindBucket(bucket)
+	if err != nil {
+		return nil, err
 	}
 
 	storage = &B2Storage{
-		clients: clients,
+		client: client,
 	}
 
 	storage.DerivedStorage = storage
@@ -56,7 +50,7 @@ func (storage *B2Storage) ListFiles(threadIndex int, dir string) (files []string
 		includeVersions = true
 	}
 
-	entries, err := storage.clients[threadIndex].ListFileNames(dir, false, includeVersions)
+	entries, err := storage.client.ListFileNames(threadIndex, dir, false, includeVersions)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -102,7 +96,7 @@ func (storage *B2Storage) DeleteFile(threadIndex int, filePath string) (err erro
 
 	if strings.HasSuffix(filePath, ".fsl") {
 		filePath = filePath[:len(filePath)-len(".fsl")]
-		entries, err := storage.clients[threadIndex].ListFileNames(filePath, true, true)
+		entries, err := storage.client.ListFileNames(threadIndex, filePath, true, true)
 		if err != nil {
 			return err
 		}
@@ -116,7 +110,7 @@ func (storage *B2Storage) DeleteFile(threadIndex int, filePath string) (err erro
 
 			toBeDeleted = true
 
-			err = storage.clients[threadIndex].DeleteFile(filePath, entry.FileID)
+			err = storage.client.DeleteFile(threadIndex, filePath, entry.FileID)
 			if err != nil {
 				return err
 			}
@@ -125,7 +119,7 @@ func (storage *B2Storage) DeleteFile(threadIndex int, filePath string) (err erro
 		return nil
 
 	} else {
-		entries, err := storage.clients[threadIndex].ListFileNames(filePath, true, false)
+		entries, err := storage.client.ListFileNames(threadIndex, filePath, true, false)
 		if err != nil {
 			return err
 		}
@@ -133,7 +127,7 @@ func (storage *B2Storage) DeleteFile(threadIndex int, filePath string) (err erro
 		if len(entries) == 0 {
 			return nil
 		}
-		return storage.clients[threadIndex].DeleteFile(filePath, entries[0].FileID)
+		return storage.client.DeleteFile(threadIndex, filePath, entries[0].FileID)
 	}
 }
 
@@ -160,10 +154,10 @@ func (storage *B2Storage) MoveFile(threadIndex int, from string, to string) (err
 	}
 
 	if filePath == from {
-		_, err = storage.clients[threadIndex].HideFile(from)
+		_, err = storage.client.HideFile(threadIndex, from)
 		return err
 	} else {
-		entries, err := storage.clients[threadIndex].ListFileNames(filePath, true, true)
+		entries, err := storage.client.ListFileNames(threadIndex, filePath, true, true)
 		if err != nil {
 			return err
 		}
@@ -171,7 +165,7 @@ func (storage *B2Storage) MoveFile(threadIndex int, from string, to string) (err
 			return nil
 		}
 
-		return storage.clients[threadIndex].DeleteFile(filePath, entries[0].FileID)
+		return storage.client.DeleteFile(threadIndex, filePath, entries[0].FileID)
 	}
 }
 
@@ -188,7 +182,7 @@ func (storage *B2Storage) GetFileInfo(threadIndex int, filePath string) (exist b
 		filePath = filePath[:len(filePath)-len(".fsl")]
 	}
 
-	entries, err := storage.clients[threadIndex].ListFileNames(filePath, true, isFossil)
+	entries, err := storage.client.ListFileNames(threadIndex, filePath, true, isFossil)
 	if err != nil {
 		return false, false, 0, err
 	}
@@ -211,21 +205,21 @@ func (storage *B2Storage) GetFileInfo(threadIndex int, filePath string) (exist b
 func (storage *B2Storage) DownloadFile(threadIndex int, filePath string, chunk *Chunk) (err error) {
 
 	filePath = strings.Replace(filePath, " ", "%20", -1)
-	readCloser, _, err := storage.clients[threadIndex].DownloadFile(filePath)
+	readCloser, _, err := storage.client.DownloadFile(threadIndex, filePath)
 	if err != nil {
 		return err
 	}
 
 	defer readCloser.Close()
 
-	_, err = RateLimitedCopy(chunk, readCloser, storage.DownloadRateLimit/len(storage.clients))
+	_, err = RateLimitedCopy(chunk, readCloser, storage.DownloadRateLimit/storage.client.Threads)
 	return err
 }
 
 // UploadFile writes 'content' to the file at 'filePath'.
 func (storage *B2Storage) UploadFile(threadIndex int, filePath string, content []byte) (err error) {
 	filePath = strings.Replace(filePath, " ", "%20", -1)
-	return storage.clients[threadIndex].UploadFile(filePath, content, storage.UploadRateLimit/len(storage.clients))
+	return storage.client.UploadFile(threadIndex, filePath, content, storage.UploadRateLimit/storage.client.Threads)
 }
 
 // If a local snapshot cache is needed for the storage to avoid downloading/uploading chunks too often when
@@ -243,7 +237,5 @@ func (storage *B2Storage) IsFastListing() bool { return true }
 
 // Enable the test mode.
 func (storage *B2Storage) EnableTestMode() {
-	for _, client := range storage.clients {
-		client.TestMode = true
-	}
+	storage.client.TestMode = true
 }

src/duplicacy_storage.go

@@ -526,11 +526,12 @@ func CreateStorage(preference Preference, resetPassword bool, threads int) (stor
 		return dropboxStorage
 	} else if matched[1] == "b2" {
 		bucket := matched[3]
+		storageDir := matched[5]
 
-		accountID := GetPassword(preference, "b2_id", "Enter Backblaze Account or Application ID:", true, resetPassword)
-		applicationKey := GetPassword(preference, "b2_key", "Enter Corresponding Backblaze Application Key:", true, resetPassword)
+		accountID := GetPassword(preference, "b2_id", "Enter Backblaze account or application id:", true, resetPassword)
+		applicationKey := GetPassword(preference, "b2_key", "Enter corresponding Backblaze application key:", true, resetPassword)
 
-		b2Storage, err := CreateB2Storage(accountID, applicationKey, bucket, threads)
+		b2Storage, err := CreateB2Storage(accountID, applicationKey, bucket, storageDir, threads)
 		if err != nil {
 			LOG_ERROR("STORAGE_CREATE", "Failed to load the Backblaze B2 storage at %s: %v", storageURL, err)
 			return nil

src/duplicacy_storage_test.go

@@ -107,7 +107,7 @@ func loadStorage(localStoragePath string, threads int) (Storage, error) {
 		storage.SetDefaultNestingLevels([]int{2, 3}, 2)
 		return storage, err
 	} else if testStorageName == "b2" {
-		storage, err := CreateB2Storage(config["account"], config["key"], config["bucket"], threads)
+		storage, err := CreateB2Storage(config["account"], config["key"], config["bucket"], config["directory"], threads)
 		storage.SetDefaultNestingLevels([]int{2, 3}, 2)
 		return storage, err
 	} else if testStorageName == "gcs-s3" {
@@ -296,7 +296,8 @@ func TestStorage(t *testing.T) {
 
 	LOG_INFO("STORAGE_TEST", "storage: %s", testStorageName)
 
-	storage, err := loadStorage(testDir, 1)
+	threads := 8
+	storage, err := loadStorage(testDir, threads)
 	if err != nil {
 		t.Errorf("Failed to create storage: %v", err)
 		return
@@ -326,16 +327,16 @@ func TestStorage(t *testing.T) {
 	storage.CreateDirectory(0, "shared")
 
 	// Upload to the same directory by multiple goroutines
-	count := 8
+	count := threads
 	finished := make(chan int, count)
 	for i := 0; i < count; i++ {
-		go func(name string) {
-			err := storage.UploadFile(0, name, []byte("this is a test file"))
+		go func(threadIndex int, name string) {
+			err := storage.UploadFile(threadIndex, name, []byte("this is a test file"))
 			if err != nil {
 				t.Errorf("Error to upload '%s': %v", name, err)
 			}
 			finished <- 0
-		}(fmt.Sprintf("shared/a/b/c/%d", i))
+		}(i, fmt.Sprintf("shared/a/b/c/%d", i))
 	}
 
 	for i := 0; i < count; i++ {
@@ -384,7 +385,6 @@ func TestStorage(t *testing.T) {
 
 	snapshotIDs := []string{}
 	for _, snapshotDir := range snapshotDirs {
-		LOG_INFO("debug", "snapshot dir: %s", snapshotDir)
 		if len(snapshotDir) > 0 && snapshotDir[len(snapshotDir)-1] == '/' {
 			snapshotIDs = append(snapshotIDs, snapshotDir[:len(snapshotDir)-1])
 		}