40 lines
997 B
Go
40 lines
997 B
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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// Package progresstracking provides wrappers around io.Reader and io.Writer
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// that track progress.
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package progresstracking
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import (
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"io"
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"time"
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)
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// NewReader wraps the given Reader with a progress tracking Reader that
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// reports progress at the following points:
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//
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// - First read
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// - Every read spaced at least interval since the prior read
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// - Last read
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func NewReader(r io.Reader, interval time.Duration, onProgress func(totalRead int, err error)) io.Reader {
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return &reader{Reader: r, interval: interval, onProgress: onProgress}
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}
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type reader struct {
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io.Reader
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interval time.Duration
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onProgress func(int, error)
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lastTracked time.Time
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totalRead int
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}
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func (r *reader) Read(p []byte) (int, error) {
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n, err := r.Reader.Read(p)
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r.totalRead += n
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if time.Since(r.lastTracked) > r.interval || err != nil {
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r.onProgress(r.totalRead, err)
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r.lastTracked = time.Now()
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}
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return n, err
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}
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