66 lines
2.2 KiB
Go
66 lines
2.2 KiB
Go
package s3manager
|
|
|
|
import (
|
|
"io"
|
|
"sync"
|
|
)
|
|
|
|
// ReadSeekerWriteTo defines an interface implementing io.WriteTo and io.ReadSeeker
|
|
type ReadSeekerWriteTo interface {
|
|
io.ReadSeeker
|
|
io.WriterTo
|
|
}
|
|
|
|
// BufferedReadSeekerWriteTo wraps a BufferedReadSeeker with an io.WriteAt
|
|
// implementation.
|
|
type BufferedReadSeekerWriteTo struct {
|
|
*BufferedReadSeeker
|
|
}
|
|
|
|
// WriteTo writes to the given io.Writer from BufferedReadSeeker until there's no more data to write or
|
|
// an error occurs. Returns the number of bytes written and any error encountered during the write.
|
|
func (b *BufferedReadSeekerWriteTo) WriteTo(writer io.Writer) (int64, error) {
|
|
return io.Copy(writer, b.BufferedReadSeeker)
|
|
}
|
|
|
|
// ReadSeekerWriteToProvider provides an implementation of io.WriteTo for an io.ReadSeeker
|
|
type ReadSeekerWriteToProvider interface {
|
|
GetWriteTo(seeker io.ReadSeeker) (r ReadSeekerWriteTo, cleanup func())
|
|
}
|
|
|
|
// BufferedReadSeekerWriteToPool uses a sync.Pool to create and reuse
|
|
// []byte slices for buffering parts in memory
|
|
type BufferedReadSeekerWriteToPool struct {
|
|
pool sync.Pool
|
|
}
|
|
|
|
// NewBufferedReadSeekerWriteToPool will return a new BufferedReadSeekerWriteToPool that will create
|
|
// a pool of reusable buffers . If size is less then < 64 KiB then the buffer
|
|
// will default to 64 KiB. Reason: io.Copy from writers or readers that don't support io.WriteTo or io.ReadFrom
|
|
// respectively will default to copying 32 KiB.
|
|
func NewBufferedReadSeekerWriteToPool(size int) *BufferedReadSeekerWriteToPool {
|
|
if size < 65536 {
|
|
size = 65536
|
|
}
|
|
|
|
return &BufferedReadSeekerWriteToPool{
|
|
pool: sync.Pool{New: func() interface{} {
|
|
return make([]byte, size)
|
|
}},
|
|
}
|
|
}
|
|
|
|
// GetWriteTo will wrap the provided io.ReadSeeker with a BufferedReadSeekerWriteTo.
|
|
// The provided cleanup must be called after operations have been completed on the
|
|
// returned io.ReadSeekerWriteTo in order to signal the return of resources to the pool.
|
|
func (p *BufferedReadSeekerWriteToPool) GetWriteTo(seeker io.ReadSeeker) (r ReadSeekerWriteTo, cleanup func()) {
|
|
buffer := p.pool.Get().([]byte)
|
|
|
|
r = &BufferedReadSeekerWriteTo{BufferedReadSeeker: NewBufferedReadSeeker(seeker, buffer)}
|
|
cleanup = func() {
|
|
p.pool.Put(buffer)
|
|
}
|
|
|
|
return r, cleanup
|
|
}
|