1 files changed, 265 insertions, 0 deletions
diff --git a/vendor/google.golang.org/api/internal/gensupport/resumable.go b/vendor/google.golang.org/api/internal/gensupport/resumable.go
new file mode 100644
index 0000000..ee8e9f3
--- /dev/null
+++ b/vendor/google.golang.org/api/internal/gensupport/resumable.go
@@ -0,0 +1,265 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gensupport
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/google/uuid"
+	"google.golang.org/api/internal"
+)
+
+// ResumableUpload is used by the generated APIs to provide resumable uploads.
+// It is not used by developers directly.
+type ResumableUpload struct {
+	Client *http.Client
+	// URI is the resumable resource destination provided by the server after specifying "&uploadType=resumable".
+	URI       string
+	UserAgent string // User-Agent for header of the request
+	// Media is the object being uploaded.
+	Media *MediaBuffer
+	// MediaType defines the media type, e.g. "image/jpeg".
+	MediaType string
+
+	mu       sync.Mutex // guards progress
+	progress int64      // number of bytes uploaded so far
+
+	// Callback is an optional function that will be periodically called with the cumulative number of bytes uploaded.
+	Callback func(int64)
+
+	// Retry optionally configures retries for requests made against the upload.
+	Retry *RetryConfig
+
+	// ChunkRetryDeadline configures the per-chunk deadline after which no further
+	// retries should happen.
+	ChunkRetryDeadline time.Duration
+
+	// Track current request invocation ID and attempt count for retry metric
+	// headers.
+	invocationID string
+	attempts     int
+}
+
+// Progress returns the number of bytes uploaded at this point.
+func (rx *ResumableUpload) Progress() int64 {
+	rx.mu.Lock()
+	defer rx.mu.Unlock()
+	return rx.progress
+}
+
+// doUploadRequest performs a single HTTP request to upload data.
+// off specifies the offset in rx.Media from which data is drawn.
+// size is the number of bytes in data.
+// final specifies whether data is the final chunk to be uploaded.
+func (rx *ResumableUpload) doUploadRequest(ctx context.Context, data io.Reader, off, size int64, final bool) (*http.Response, error) {
+	req, err := http.NewRequest("POST", rx.URI, data)
+	if err != nil {
+		return nil, err
+	}
+
+	req.ContentLength = size
+	var contentRange string
+	if final {
+		if size == 0 {
+			contentRange = fmt.Sprintf("bytes */%v", off)
+		} else {
+			contentRange = fmt.Sprintf("bytes %v-%v/%v", off, off+size-1, off+size)
+		}
+	} else {
+		contentRange = fmt.Sprintf("bytes %v-%v/*", off, off+size-1)
+	}
+	req.Header.Set("Content-Range", contentRange)
+	req.Header.Set("Content-Type", rx.MediaType)
+	req.Header.Set("User-Agent", rx.UserAgent)
+
+	baseXGoogHeader := "gl-go/" + GoVersion() + " gdcl/" + internal.Version
+	invocationHeader := fmt.Sprintf("gccl-invocation-id/%s gccl-attempt-count/%d", rx.invocationID, rx.attempts)
+	req.Header.Set("X-Goog-Api-Client", strings.Join([]string{baseXGoogHeader, invocationHeader}, " "))
+
+	// Google's upload endpoint uses status code 308 for a
+	// different purpose than the "308 Permanent Redirect"
+	// since-standardized in RFC 7238. Because of the conflict in
+	// semantics, Google added this new request header which
+	// causes it to not use "308" and instead reply with 200 OK
+	// and sets the upload-specific "X-HTTP-Status-Code-Override:
+	// 308" response header.
+	req.Header.Set("X-GUploader-No-308", "yes")
+
+	return SendRequest(ctx, rx.Client, req)
+}
+
+func statusResumeIncomplete(resp *http.Response) bool {
+	// This is how the server signals "status resume incomplete"
+	// when X-GUploader-No-308 is set to "yes":
+	return resp != nil && resp.Header.Get("X-Http-Status-Code-Override") == "308"
+}
+
+// reportProgress calls a user-supplied callback to report upload progress.
+// If old==updated, the callback is not called.
+func (rx *ResumableUpload) reportProgress(old, updated int64) {
+	if updated-old == 0 {
+		return
+	}
+	rx.mu.Lock()
+	rx.progress = updated
+	rx.mu.Unlock()
+	if rx.Callback != nil {
+		rx.Callback(updated)
+	}
+}
+
+// transferChunk performs a single HTTP request to upload a single chunk from rx.Media.
+func (rx *ResumableUpload) transferChunk(ctx context.Context) (*http.Response, error) {
+	chunk, off, size, err := rx.Media.Chunk()
+
+	done := err == io.EOF
+	if !done && err != nil {
+		return nil, err
+	}
+
+	res, err := rx.doUploadRequest(ctx, chunk, off, int64(size), done)
+	if err != nil {
+		return res, err
+	}
+
+	// We sent "X-GUploader-No-308: yes" (see comment elsewhere in
+	// this file), so we don't expect to get a 308.
+	if res.StatusCode == 308 {
+		return nil, errors.New("unexpected 308 response status code")
+	}
+
+	if res.StatusCode == http.StatusOK {
+		rx.reportProgress(off, off+int64(size))
+	}
+
+	if statusResumeIncomplete(res) {
+		rx.Media.Next()
+	}
+	return res, nil
+}
+
+// Upload starts the process of a resumable upload with a cancellable context.
+// It retries using the provided back off strategy until cancelled or the
+// strategy indicates to stop retrying.
+// It is called from the auto-generated API code and is not visible to the user.
+// Before sending an HTTP request, Upload calls any registered hook functions,
+// and calls the returned functions after the request returns (see send.go).
+// rx is private to the auto-generated API code.
+// Exactly one of resp or err will be nil.  If resp is non-nil, the caller must call resp.Body.Close.
+func (rx *ResumableUpload) Upload(ctx context.Context) (resp *http.Response, err error) {
+
+	// There are a couple of cases where it's possible for err and resp to both
+	// be non-nil. However, we expose a simpler contract to our callers: exactly
+	// one of resp and err will be non-nil. This means that any response body
+	// must be closed here before returning a non-nil error.
+	var prepareReturn = func(resp *http.Response, err error) (*http.Response, error) {
+		if err != nil {
+			if resp != nil && resp.Body != nil {
+				resp.Body.Close()
+			}
+			return nil, err
+		}
+		// This case is very unlikely but possible only if rx.ChunkRetryDeadline is
+		// set to a very small value, in which case no requests will be sent before
+		// the deadline. Return an error to avoid causing a panic.
+		if resp == nil {
+			return nil, fmt.Errorf("upload request to %v not sent, choose larger value for ChunkRetryDealine", rx.URI)
+		}
+		return resp, nil
+	}
+	// Configure retryable error criteria.
+	errorFunc := rx.Retry.errorFunc()
+
+	// Configure per-chunk retry deadline.
+	var retryDeadline time.Duration
+	if rx.ChunkRetryDeadline != 0 {
+		retryDeadline = rx.ChunkRetryDeadline
+	} else {
+		retryDeadline = defaultRetryDeadline
+	}
+
+	// Send all chunks.
+	for {
+		var pause time.Duration
+
+		// Each chunk gets its own initialized-at-zero backoff and invocation ID.
+		bo := rx.Retry.backoff()
+		quitAfterTimer := time.NewTimer(retryDeadline)
+		rx.attempts = 1
+		rx.invocationID = uuid.New().String()
+
+		// Retry loop for a single chunk.
+		for {
+			pauseTimer := time.NewTimer(pause)
+			select {
+			case <-ctx.Done():
+				quitAfterTimer.Stop()
+				pauseTimer.Stop()
+				if err == nil {
+					err = ctx.Err()
+				}
+				return prepareReturn(resp, err)
+			case <-pauseTimer.C:
+				quitAfterTimer.Stop()
+			case <-quitAfterTimer.C:
+				pauseTimer.Stop()
+				return prepareReturn(resp, err)
+			}
+			pauseTimer.Stop()
+
+			// Check for context cancellation or timeout once more. If more than one
+			// case in the select statement above was satisfied at the same time, Go
+			// will choose one arbitrarily.
+			// That can cause an operation to go through even if the context was
+			// canceled before or the timeout was reached.
+			select {
+			case <-ctx.Done():
+				quitAfterTimer.Stop()
+				if err == nil {
+					err = ctx.Err()
+				}
+				return prepareReturn(resp, err)
+			case <-quitAfterTimer.C:
+				return prepareReturn(resp, err)
+			default:
+				quitAfterTimer.Stop()
+			}
+
+			resp, err = rx.transferChunk(ctx)
+
+			var status int
+			if resp != nil {
+				status = resp.StatusCode
+			}
+
+			// Check if we should retry the request.
+			if !errorFunc(status, err) {
+				break
+			}
+
+			rx.attempts++
+			pause = bo.Pause()
+			if resp != nil && resp.Body != nil {
+				resp.Body.Close()
+			}
+		}
+
+		// If the chunk was uploaded successfully, but there's still
+		// more to go, upload the next chunk without any delay.
+		if statusResumeIncomplete(resp) {
+			resp.Body.Close()
+			continue
+		}
+
+		return prepareReturn(resp, err)
+	}
+}