63 lines
1.2 KiB
Go
63 lines
1.2 KiB
Go
// Package seekbuf implements a read-seekable buffer.
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package seekbuf
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import "io"
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// Buffer is a ReadWriteCloser that supports seeking. It's intended to
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// replicate the functionality of bytes.Buffer that I use in my projects.
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//
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// Note that the seeking is limited to the read marker; all writes are
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// append-only.
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type Buffer struct {
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data []byte
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pos int
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}
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func New(data []byte) *Buffer {
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return &Buffer{
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data: data,
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}
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}
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func (b *Buffer) Read(p []byte) (int, error) {
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if b.pos >= len(b.data) {
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return 0, io.EOF
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}
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n := copy(p, b.data[b.pos:])
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b.pos += n
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return n, nil
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}
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func (b *Buffer) Write(p []byte) (int, error) {
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b.data = append(b.data, p...)
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return len(p), nil
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}
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// Seek sets the read pointer to pos.
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func (b *Buffer) Seek(pos int) {
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b.pos = pos
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}
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// Rewind resets the read pointer to 0.
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func (b *Buffer) Rewind() {
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b.Seek(0)
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}
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// Close clears all the data out of the buffer and sets the read position to 0.
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func (b *Buffer) Close() error {
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b.data = nil
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b.pos = 0
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return nil
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}
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// Len returns the length of data remaining to be read.
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func (b *Buffer) Len() int {
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return len(b.data[b.pos:])
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}
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// Bytes returns the underlying bytes from the current position.
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func (b *Buffer) Bytes() []byte {
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return b.data[b.pos:]
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}
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