50 lines
1.0 KiB
Go
50 lines
1.0 KiB
Go
package main
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import (
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"fmt"
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"sync"
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)
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// limitedBuffer keeps only the last maxLen bytes written to it — used to
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// capture a bounded tail of a subprocess's stderr for error messages
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// without risking unbounded memory growth from a noisy remote command.
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type limitedBuffer struct {
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mu sync.Mutex
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buf []byte
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maxLen int
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}
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func newLimitedBuffer(maxLen int) *limitedBuffer {
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return &limitedBuffer{maxLen: maxLen}
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}
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func (b *limitedBuffer) Write(p []byte) (int, error) {
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b.mu.Lock()
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defer b.mu.Unlock()
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b.buf = append(b.buf, p...)
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if len(b.buf) > b.maxLen {
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b.buf = b.buf[len(b.buf)-b.maxLen:]
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}
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return len(p), nil
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}
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func (b *limitedBuffer) String() string {
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b.mu.Lock()
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defer b.mu.Unlock()
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return string(b.buf)
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}
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func humanBytes(n int64) string {
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const unit = 1024
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if n < unit {
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return fmt.Sprintf("%d B", n)
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}
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div, exp := int64(unit), 0
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for m := n / unit; m >= unit; m /= unit {
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div *= unit
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exp++
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}
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units := "KMGTPE"
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return fmt.Sprintf("%.1f%ciB", float64(n)/float64(div), units[exp])
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}
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