Платформа ЦРНП "Мирокод" для разработки проектов
https://git.mirocod.ru
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58 lines
1.2 KiB
58 lines
1.2 KiB
package buffer |
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import ( |
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"io" |
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"math" |
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"github.com/djherbis/buffer/wrapio" |
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) |
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type ring struct { |
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BufferAt |
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L int64 |
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*wrapio.WrapReader |
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*wrapio.WrapWriter |
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} |
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// NewRing returns a Ring Buffer from a BufferAt. |
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// It overwrites old data in the Buffer when needed (when its full). |
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func NewRing(buffer BufferAt) Buffer { |
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return &ring{ |
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BufferAt: buffer, |
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WrapReader: wrapio.NewWrapReader(buffer, 0, buffer.Cap()), |
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WrapWriter: wrapio.NewWrapWriter(buffer, 0, buffer.Cap()), |
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} |
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} |
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func (buf *ring) Len() int64 { |
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return buf.L |
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} |
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func (buf *ring) Cap() int64 { |
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return math.MaxInt64 |
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} |
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func (buf *ring) Read(p []byte) (n int, err error) { |
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if buf.L == buf.BufferAt.Cap() { |
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buf.WrapReader.Seek(buf.WrapWriter.Offset(), 0) |
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} |
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n, err = io.LimitReader(buf.WrapReader, buf.L).Read(p) |
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buf.L -= int64(n) |
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return n, err |
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} |
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func (buf *ring) Write(p []byte) (n int, err error) { |
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n, err = buf.WrapWriter.Write(p) |
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buf.L += int64(n) |
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if buf.L > buf.BufferAt.Cap() { |
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buf.L = buf.BufferAt.Cap() |
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} |
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return n, err |
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} |
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func (buf *ring) Reset() { |
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buf.BufferAt.Reset() |
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buf.L = 0 |
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buf.WrapReader = wrapio.NewWrapReader(buf.BufferAt, 0, buf.BufferAt.Cap()) |
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buf.WrapWriter = wrapio.NewWrapWriter(buf.BufferAt, 0, buf.BufferAt.Cap()) |
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}
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