da849d96b5
Adds ReadContext/WriteContext methods to endpoints and to streams. Update rawread example tool to use ReadContext for implementation of "timeout" flag.
59 lines
2.0 KiB
Go
59 lines
2.0 KiB
Go
// Copyright 2017 the gousb Authors. All rights reserved.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package gousb
|
|
|
|
func (e *endpoint) newStream(size, count int) (*stream, error) {
|
|
var ts []transferIntf
|
|
for i := 0; i < count; i++ {
|
|
t, err := newUSBTransfer(e.ctx, e.h, &e.Desc, size)
|
|
if err != nil {
|
|
for _, t := range ts {
|
|
t.free()
|
|
}
|
|
return nil, err
|
|
}
|
|
ts = append(ts, t)
|
|
}
|
|
return newStream(ts), nil
|
|
}
|
|
|
|
// NewStream prepares a new read stream that will keep reading data from
|
|
// the endpoint until closed or until an error or timeout is encountered.
|
|
// Size defines a buffer size for a single read transaction and count
|
|
// defines how many transactions should be active at any time.
|
|
// By keeping multiple transfers active at the same time, a Stream reduces
|
|
// the latency between subsequent transfers and increases reading throughput.
|
|
func (e *InEndpoint) NewStream(size, count int) (*ReadStream, error) {
|
|
s, err := e.newStream(size, count)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
s.submitAll()
|
|
return &ReadStream{s: s}, nil
|
|
}
|
|
|
|
// NewStream prepares a new write stream that will write data in the
|
|
// background. Size defines a buffer size for a single write transaction and
|
|
// count defines how many transactions may be active at any time. By buffering
|
|
// the writes, a Stream reduces the latency between subsequent transfers and
|
|
// increases writing throughput.
|
|
func (e *OutEndpoint) NewStream(size, count int) (*WriteStream, error) {
|
|
s, err := e.newStream(size, count)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &WriteStream{s: s}, nil
|
|
}
|