82 lines
2.5 KiB
Go
Executable file
82 lines
2.5 KiB
Go
Executable file
package pipeline
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import "io"
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// ********** The following is common between the request body AND the response body.
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// ProgressReceiver defines the signature of a callback function invoked as progress is reported.
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type ProgressReceiver func(bytesTransferred int64)
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// ********** The following are specific to the request body (a ReadSeekCloser)
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// This struct is used when sending a body to the network
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type requestBodyProgress struct {
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requestBody io.ReadSeeker // Seeking is required to support retries
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pr ProgressReceiver
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}
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// NewRequestBodyProgress adds progress reporting to an HTTP request's body stream.
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func NewRequestBodyProgress(requestBody io.ReadSeeker, pr ProgressReceiver) io.ReadSeeker {
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if pr == nil {
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panic("pr must not be nil")
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}
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return &requestBodyProgress{requestBody: requestBody, pr: pr}
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}
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// Read reads a block of data from an inner stream and reports progress
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func (rbp *requestBodyProgress) Read(p []byte) (n int, err error) {
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n, err = rbp.requestBody.Read(p)
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if err != nil {
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return
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}
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// Invokes the user's callback method to report progress
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position, err := rbp.requestBody.Seek(0, io.SeekCurrent)
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if err != nil {
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panic(err)
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}
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rbp.pr(position)
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return
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}
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func (rbp *requestBodyProgress) Seek(offset int64, whence int) (offsetFromStart int64, err error) {
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return rbp.requestBody.Seek(offset, whence)
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}
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// requestBodyProgress supports Close but the underlying stream may not; if it does, Close will close it.
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func (rbp *requestBodyProgress) Close() error {
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if c, ok := rbp.requestBody.(io.Closer); ok {
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return c.Close()
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}
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return nil
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}
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// ********** The following are specific to the response body (a ReadCloser)
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// This struct is used when sending a body to the network
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type responseBodyProgress struct {
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responseBody io.ReadCloser
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pr ProgressReceiver
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offset int64
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}
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// NewResponseBodyProgress adds progress reporting to an HTTP response's body stream.
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func NewResponseBodyProgress(responseBody io.ReadCloser, pr ProgressReceiver) io.ReadCloser {
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if pr == nil {
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panic("pr must not be nil")
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}
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return &responseBodyProgress{responseBody: responseBody, pr: pr, offset: 0}
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}
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// Read reads a block of data from an inner stream and reports progress
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func (rbp *responseBodyProgress) Read(p []byte) (n int, err error) {
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n, err = rbp.responseBody.Read(p)
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rbp.offset += int64(n)
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// Invokes the user's callback method to report progress
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rbp.pr(rbp.offset)
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return
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}
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func (rbp *responseBodyProgress) Close() error {
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return rbp.responseBody.Close()
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}
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