102 lines
1.5 KiB
Go
102 lines
1.5 KiB
Go
package buffer
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import (
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"encoding/gob"
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"io"
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"math"
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)
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type partition struct {
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List
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Pool
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}
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// NewPartition returns a Buffer which uses a Pool to extend or shrink its size as needed.
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// It automatically allocates new buffers with pool.Get() to extend is length, and
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// pool.Put() to release unused buffers as it shrinks.
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func NewPartition(pool Pool, buffers ...Buffer) Buffer {
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return &partition{
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Pool: pool,
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List: buffers,
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}
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}
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func (buf *partition) Cap() int64 {
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return math.MaxInt64
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}
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func (buf *partition) Read(p []byte) (n int, err error) {
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for len(p) > 0 {
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if len(buf.List) == 0 {
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return n, io.EOF
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}
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buffer := buf.List[0]
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if Empty(buffer) {
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buf.Pool.Put(buf.Pop())
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continue
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}
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m, er := buffer.Read(p)
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n += m
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p = p[m:]
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if er != nil && er != io.EOF {
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return n, er
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}
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}
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return n, nil
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}
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func (buf *partition) grow() error {
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next, err := buf.Pool.Get()
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if err != nil {
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return err
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}
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buf.Push(next)
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return nil
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}
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func (buf *partition) Write(p []byte) (n int, err error) {
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for len(p) > 0 {
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if len(buf.List) == 0 {
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if err := buf.grow(); err != nil {
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return n, err
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}
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}
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buffer := buf.List[len(buf.List)-1]
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if Full(buffer) {
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if err := buf.grow(); err != nil {
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return n, err
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}
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continue
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}
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m, er := buffer.Write(p)
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n += m
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p = p[m:]
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if er != nil && er != io.ErrShortWrite {
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return n, er
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}
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}
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return n, nil
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}
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func (buf *partition) Reset() {
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for len(buf.List) > 0 {
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buf.Pool.Put(buf.Pop())
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}
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}
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func init() {
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gob.Register(&partition{})
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}
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