Платформа ЦРНП "Мирокод" для разработки проектов
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48 lines
1.3 KiB
48 lines
1.3 KiB
// Package buffer implements a series of Buffers which can be composed to implement complicated buffering strategies |
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package buffer |
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import ( |
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"io" |
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"os" |
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) |
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// Buffer is used to Write() data which will be Read() later. |
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type Buffer interface { |
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Len() int64 // How much data is Buffered in bytes |
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Cap() int64 // How much data can be Buffered at once in bytes. |
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io.Reader // Read() will read from the top of the buffer [io.EOF if empty] |
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io.Writer // Write() will write to the end of the buffer [io.ErrShortWrite if not enough space] |
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Reset() // Truncates the buffer, Len() == 0. |
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} |
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// BufferAt is a buffer which supports io.ReaderAt and io.WriterAt |
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type BufferAt interface { |
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Buffer |
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io.ReaderAt |
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io.WriterAt |
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} |
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func len64(p []byte) int64 { |
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return int64(len(p)) |
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} |
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// Gap returns buf.Cap() - buf.Len() |
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func Gap(buf Buffer) int64 { |
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return buf.Cap() - buf.Len() |
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} |
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// Full returns true iff buf.Len() == buf.Cap() |
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func Full(buf Buffer) bool { |
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return buf.Len() == buf.Cap() |
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} |
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// Empty returns false iff buf.Len() == 0 |
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func Empty(buf Buffer) bool { |
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return buf.Len() == 0 |
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} |
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// NewUnboundedBuffer returns a Buffer which buffers "mem" bytes to memory |
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// and then creates file's of size "file" to buffer above "mem" bytes. |
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func NewUnboundedBuffer(mem, file int64) Buffer { |
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return NewMulti(New(mem), NewPartition(NewFilePool(file, os.TempDir()))) |
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}
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