Struct: s3manager.BufferedReadSeeker

import "../ibm-cos-sdk-go/service/s3/s3manager"

Overview

BufferedReadSeeker is buffered io.ReadSeeker

Implemented Interfaces

s3crypto.Cipher, s3manager.ReadSeekerWriteTo, s3manager.WriterReadFrom

Constructor Functions collapse

Method Summary collapse

Function Details

func NewBufferedReadSeeker(r io.ReadSeeker, b []byte) *BufferedReadSeeker

NewBufferedReadSeeker returns a new BufferedReadSeeker if len(b) == 0 then the buffer will be initialized to 64 KiB.



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// File 'service/s3/s3manager/buffered_read_seeker.go', line 17


func NewBufferedReadSeeker(r io.ReadSeeker, b []byte) *BufferedReadSeeker {
	if len(b) == 0 {
		b = make([]byte, 64*1024)
	}
	return &BufferedReadSeeker{r: r, buffer: b}
}

Method Details

func (b *BufferedReadSeeker) Read(p []byte) (n int, err error)

Read will read up len(p) bytes into p and will return the number of bytes read and any error that occurred. If the len(p) > the buffer size then a single read request will be issued to the underlying io.ReadSeeker for len(p) bytes. A Read request will at most perform a single Read to the underlying io.ReadSeeker, and may return < len(p) if serviced from the buffer.



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// File 'service/s3/s3manager/buffered_read_seeker.go', line 35


func (b *BufferedReadSeeker) Read(p []byte) (n int, err error) {
	if len(p) == 0 {
		return n, err
	}

	if b.readIdx == b.writeIdx {
		if len(p) >= len(b.buffer) {
			n, err = b.r.Read(p)
			return n, err
		}
		b.readIdx, b.writeIdx = 0, 0

		n, err = b.r.Read(b.buffer)
		if n == 0 {
			return n, err
		}

		b.writeIdx += n
	}

	n = copy(p, b.buffer[b.readIdx:b.writeIdx])
	b.readIdx += n

	return n, err
}

func (b *BufferedReadSeeker) ReadAt(p []byte, off int64) (int, error)

ReadAt will read up to len(p) bytes at the given file offset. This will result in the buffer being cleared.



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// File 'service/s3/s3manager/buffered_read_seeker.go', line 73


func (b *BufferedReadSeeker) ReadAt(p []byte, off int64) (int, error) {
	_, err := b.Seek(off, sdkio.SeekStart)
	if err != nil {
		return 0, err
	}

	return b.Read(p)
}

func (b *BufferedReadSeeker) Seek(offset int64, whence int) (int64, error)

Seek will position then underlying io.ReadSeeker to the given offset and will clear the buffer.



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// File 'service/s3/s3manager/buffered_read_seeker.go', line 63


func (b *BufferedReadSeeker) Seek(offset int64, whence int) (int64, error) {
	n, err := b.r.Seek(offset, whence)

	b.reset(b.r)

	return n, err
}