diff options
author | Niall Sheridan <nsheridan@gmail.com> | 2016-05-22 01:23:33 +0100 |
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committer | Niall Sheridan <nsheridan@gmail.com> | 2016-05-22 01:23:33 +0100 |
commit | 649bf79117e30895108b7782d62daafd07bc5e6e (patch) | |
tree | fbee9fcd5374b87e75f85c0f1bf3a0d45aa6de67 /vendor/google.golang.org/api/gensupport/retry.go | |
parent | 1b21181bda148118b56221fe35b8dac3cd40bb50 (diff) |
Use govendor
Diffstat (limited to 'vendor/google.golang.org/api/gensupport/retry.go')
-rw-r--r-- | vendor/google.golang.org/api/gensupport/retry.go | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/vendor/google.golang.org/api/gensupport/retry.go b/vendor/google.golang.org/api/gensupport/retry.go new file mode 100644 index 0000000..7f83d1d --- /dev/null +++ b/vendor/google.golang.org/api/gensupport/retry.go @@ -0,0 +1,77 @@ +package gensupport + +import ( + "io" + "net" + "net/http" + "time" + + "golang.org/x/net/context" +) + +// Retry invokes the given function, retrying it multiple times if the connection failed or +// the HTTP status response indicates the request should be attempted again. ctx may be nil. +func Retry(ctx context.Context, f func() (*http.Response, error), backoff BackoffStrategy) (*http.Response, error) { + for { + resp, err := f() + + var status int + if resp != nil { + status = resp.StatusCode + } + + // Return if we shouldn't retry. + pause, retry := backoff.Pause() + if !shouldRetry(status, err) || !retry { + return resp, err + } + + // Ensure the response body is closed, if any. + if resp != nil && resp.Body != nil { + resp.Body.Close() + } + + // Pause, but still listen to ctx.Done if context is not nil. + var done <-chan struct{} + if ctx != nil { + done = ctx.Done() + } + select { + case <-done: + return nil, ctx.Err() + case <-time.After(pause): + } + } +} + +// DefaultBackoffStrategy returns a default strategy to use for retrying failed upload requests. +func DefaultBackoffStrategy() BackoffStrategy { + return &ExponentialBackoff{ + Base: 250 * time.Millisecond, + Max: 16 * time.Second, + } +} + +// shouldRetry returns true if the HTTP response / error indicates that the +// request should be attempted again. +func shouldRetry(status int, err error) bool { + // Retry for 5xx response codes. + if 500 <= status && status < 600 { + return true + } + + // Retry on statusTooManyRequests{ + if status == statusTooManyRequests { + return true + } + + // Retry on unexpected EOFs and temporary network errors. + if err == io.ErrUnexpectedEOF { + return true + } + if err, ok := err.(net.Error); ok { + return err.Temporary() + } + + return false +} |