Hojun-Cho
10672f3816
Dead, vestigial, and over-built code with no behavior change (except the
bool-vocabulary trim, a deliberate behavior tightening):
- httpdl: drop the vestigial sort+copy in validSegs (work-stealing was
removed in 270812d, so segments always tile [0,total) ascending now);
validate order in place, which also rejects a scrambled sidecar. Inline
the endOff() accessor to s.end.
- cli: shrink the boolean vocabulary to true/false, which is all that's
accepted. The invented yes/no/1/0/on/off spellings are gone, so e.g.
--enable-dht=yes (or yes in got.conf) is now a usage error.
- download: remove the dead, never-called Stat.Done() method.
- progress: drop speed(), a pure alias of humanSize; call humanSize directly.
- main: replace the jobsHolder mutex box with atomic.Pointer[[]job] for the
forced-exit session save; the capability stays, the lock and type go.
- bt: collapse isAddrInUse's X||X (missinggo.IsAddrInUse is that exact
string match); drop the now-unused missinggo import (tidy -> indirect).
- option: note that prealloc and falloc are identical here.
57 lines
1.9 KiB
Go
57 lines
1.9 KiB
Go
package httpdl
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import "sync/atomic"
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// seg is one contiguous byte range of the output file, downloaded by a single
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// ranged GET. A segment IS a byte range — a plain HTTP downloader does not need
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// the Piece/Segment/block layering that exists only to share code with
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// BitTorrent. start and end are fixed when the file is divided; written is
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// advanced (atomically) by the segment's one worker, so Stat() and the resume
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// snapshot can read its frontier while it downloads.
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type seg struct {
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index int
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start int64 // first byte offset, inclusive
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end int64 // last byte offset, inclusive
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written int64 // bytes already written into this segment (the resume point)
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}
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func (s *seg) length() int64 { return s.end - s.start + 1 }
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func (s *seg) done() bool { return atomic.LoadInt64(&s.written) >= s.length() }
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func (s *seg) addWritten(n int64) { atomic.AddInt64(&s.written, n) }
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func (s *seg) progress() int64 { return atomic.LoadInt64(&s.written) }
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func (s *seg) offset() int64 { return s.start + atomic.LoadInt64(&s.written) }
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func (s *seg) remaining() int64 { return s.length() - atomic.LoadInt64(&s.written) }
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// makeSegments divides a file of total bytes into contiguous segments, using at
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// most conns of them and never splitting below minSplit. The remainder lands in
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// the last segment. With conns==1 (the default) this yields one segment. Each
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// segment gets its own worker, so the division here fixes the parallelism: there
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// is no later rebalancing.
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func makeSegments(total, minSplit int64, conns int) []seg {
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if conns < 1 {
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conns = 1
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}
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if minSplit < 1 {
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minSplit = 1
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}
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n := int64(conns)
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if max := total / minSplit; max < n {
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n = max
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}
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if n < 1 {
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n = 1
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}
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chunk := total / n
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segs := make([]seg, n)
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var start int64
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for i := int64(0); i < n; i++ {
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end := start + chunk - 1
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if i == n-1 {
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end = total - 1
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}
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segs[i] = seg{index: int(i), start: start, end: end}
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start = end + 1
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}
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return segs
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}
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