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Merged in kortschak/av/gardening/ring (pull request #15) 

ring: new package replacement for ringbuffer
This commit is contained in:
kortschak 2018-06-07 05:54:09 +00:00
parent 16a11ec090 b7b000aeac
commit 33ef0ce11d
8 changed files with 894 additions and 1192 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

147
revid/Revid.go
View File

@ -46,7 +46,7 @@ import (
"bitbucket.org/ausocean/av/generator" "bitbucket.org/ausocean/av/generator"
"bitbucket.org/ausocean/av/parser" "bitbucket.org/ausocean/av/parser"
"bitbucket.org/ausocean/av/ringbuffer" "bitbucket.org/ausocean/av/ring"
"bitbucket.org/ausocean/av/rtmp" "bitbucket.org/ausocean/av/rtmp"
) )
@ -57,6 +57,8 @@ const (
mp2tMaxPackets = 2016 * clipDuration // # first multiple of 7 and 8 greater than 2000 mp2tMaxPackets = 2016 * clipDuration // # first multiple of 7 and 8 greater than 2000
ringBufferSize = 500 ringBufferSize = 500
ringBufferElementSize = 150000 ringBufferElementSize = 150000
writeTimeout = 10 * time.Millisecond
readTimeout = 10 * time.Millisecond
httpTimeOut = 5 // s httpTimeOut = 5 // s
packetsPerFrame = 7 packetsPerFrame = 7
bitrateTime = 60 // s bitrateTime = 60 // s
@ -98,7 +100,7 @@ type Revid interface {
type revid struct { type revid struct {
ffmpegPath string ffmpegPath string
tempDir string tempDir string
ringBuffer ringbuffer.RingBuffer ringBuffer *ring.Buffer
config Config config Config
isRunning bool isRunning bool
outputFile *os.File outputFile *os.File
@ -113,7 +115,7 @@ type revid struct {
setupInput func() error setupInput func() error
setupOutput func() error setupOutput func() error
getFrame func() []byte getFrame func() []byte
sendClip func(clip []byte) error sendClip func(*ring.Chunk) error
rtmpInst rtmp.Session rtmpInst rtmp.Session
mutex sync.Mutex mutex sync.Mutex
sendMutex sync.Mutex sendMutex sync.Mutex
@ -127,7 +129,7 @@ func NewRevid(config Config) (r *revid, err error) {
r = new(revid) r = new(revid)
r.mutex = sync.Mutex{} r.mutex = sync.Mutex{}
r.sendMutex = sync.Mutex{} r.sendMutex = sync.Mutex{}
r.ringBuffer = ringbuffer.NewRingBuffer(ringBufferSize, ringBufferElementSize) r.ringBuffer = ring.NewBuffer(ringBufferSize, ringBufferElementSize, writeTimeout)
err = r.changeState(config) err = r.changeState(config)
if err != nil { if err != nil {
r = nil r = nil
@ -161,8 +163,8 @@ func (r *revid) changeState(config Config) error {
switch r.config.Output { switch r.config.Output {
case File: case File:
r.sendClip = r.sendClipToFile
r.setupOutput = r.setupOutputForFile r.setupOutput = r.setupOutputForFile
r.sendClip = r.sendClipToFile
case FfmpegRtmp: case FfmpegRtmp:
r.setupOutput = r.setupOutputForFfmpegRtmp r.setupOutput = r.setupOutputForFfmpegRtmp
r.sendClip = r.sendClipToFfmpegRtmp r.sendClip = r.sendClipToFfmpegRtmp
@ -339,38 +341,24 @@ done:
func (r *revid) packClips() { func (r *revid) packClips() {
clipSize := 0 clipSize := 0
packetCount := 0 packetCount := 0
outputChanFullFlag := false
for r.isRunning {
// Get some memory from the ring buffer for out clip
var clip []byte
var err error
if clip, err = r.ringBuffer.Get(); err != nil && r.isRunning {
if !outputChanFullFlag {
r.Log(Error, err.Error())
r.Log(Warning, "Clearing output chan!")
outputChanFullFlag = true
}
for clip, err = r.ringBuffer.Get(); err != nil && r.isRunning; {
time.Sleep(time.Duration(10) * time.Millisecond)
clip, err = r.ringBuffer.Get()
}
r.Log(Debug, "Finally got mem from ringbuffer!")
outputChanFullFlag = false
}
for r.isRunning { for r.isRunning {
select { select {
// TODO: This is temporary, need to work out how to make this work // TODO: This is temporary, need to work out how to make this work
// for cases when there is not packetisation. // for cases when there is not packetisation.
case frame := <-(r.generator.GetOutputChan()): case frame := <-r.generator.GetOutputChan():
lenOfFrame := len(frame) lenOfFrame := len(frame)
if lenOfFrame > ringBufferElementSize { if lenOfFrame > ringBufferElementSize {
r.Log(Warning, fmt.Sprintf("Frame was too big: %v bytes, getting another one!", lenOfFrame)) r.Log(Warning, fmt.Sprintf("Frame was too big: %v bytes, getting another one!", lenOfFrame))
frame = r.getFrame() frame = r.getFrame()
lenOfFrame = len(frame) lenOfFrame = len(frame)
} }
upperBound := clipSize + lenOfFrame _, err := r.ringBuffer.Write(frame)
copy(clip[clipSize:upperBound], frame) if err != nil {
r.Log(Error, err.Error())
if err == ring.ErrDropped {
r.Log(Warning, fmt.Sprintf("dropped %d byte frame", len(frame)))
}
}
packetCount++ packetCount++
clipSize += lenOfFrame clipSize += lenOfFrame
fpcAsInt, err := strconv.Atoi(r.config.FramesPerClip) fpcAsInt, err := strconv.Atoi(r.config.FramesPerClip)
@ -379,20 +367,15 @@ func (r *revid) packClips() {
r.config.FramesPerClip = "1" r.config.FramesPerClip = "1"
} }
if packetCount >= fpcAsInt { if packetCount >= fpcAsInt {
if err := r.ringBuffer.DoneWriting(clipSize); err != nil { r.ringBuffer.Flush()
r.Log(Error, err.Error())
r.Log(Warning, "Dropping clip!")
}
clipSize = 0 clipSize = 0
packetCount = 0 packetCount = 0
goto finishedWithClip continue
} }
default: default:
time.Sleep(time.Duration(5) * time.Millisecond) time.Sleep(time.Duration(5) * time.Millisecond)
} }
} }
finishedWithClip:
}
} }
// outputClips takes the clips produced in the packClips method and outputs them // outputClips takes the clips produced in the packClips method and outputs them
@ -405,40 +388,43 @@ func (r *revid) outputClips() {
for r.isRunning { for r.isRunning {
// Here we slow things down as much as we can to decrease cpu usage // Here we slow things down as much as we can to decrease cpu usage
switch { switch {
case r.ringBuffer.GetNoOfElements() < 2: case r.ringBuffer.Len() < 2:
delay++ delay++
time.Sleep(time.Duration(delay) * time.Millisecond) time.Sleep(time.Duration(delay) * time.Millisecond)
case delay > 0: case delay > 0:
delay-- delay--
} }
// If the ringbuffer has something we can read and send off // If the ringbuffer has something we can read and send off
if clip, err := r.ringBuffer.Read(); err == nil && r.isRunning { chunk, err := r.ringBuffer.Next(readTimeout)
bytes += len(clip) if err != nil || !r.isRunning {
if err == io.EOF {
break
}
continue
}
bytes += chunk.Len()
r.Log(Detail, "About to send") r.Log(Detail, "About to send")
err2 := r.sendClip(clip) err = r.sendClip(chunk)
if err2 == nil { if err == nil {
r.Log(Detail, "Sent clip") r.Log(Detail, "Sent clip")
} }
if r.isRunning && err2 != nil && len(clip) > 11 { if r.isRunning && err != nil && chunk.Len() > 11 {
r.Log(Debug, "Send failed! Trying again") r.Log(Debug, "Send failed! Trying again")
// Try and send again // Try and send again
err2 = r.sendClip(clip) err = r.sendClip(chunk)
// if there's still an error we try and reconnect, unless we're stopping // if there's still an error we try and reconnect, unless we're stopping
for r.isRunning && err2 != nil { for r.isRunning && err != nil {
r.Log(Debug, "Send failed a again! Trying to reconnect...") r.Log(Debug, "Send failed a again! Trying to reconnect...")
time.Sleep(time.Duration(sendFailedDelay) * time.Millisecond) time.Sleep(time.Duration(sendFailedDelay) * time.Millisecond)
r.Log(Error, err2.Error()) r.Log(Error, err.Error())
if r.config.Output == NativeRtmp { if r.config.Output == NativeRtmp {
r.Log(Debug, "Ending current rtmp session...") r.Log(Debug, "Ending current rtmp session...")
r.rtmpInst.Close() r.rtmpInst.Close()
} }
if r.ringBuffer.Full() {
r.Log(Debug, "Flushing incoming data...")
r.flushData()
}
if r.config.Output == NativeRtmp { if r.config.Output == NativeRtmp {
r.Log(Info, "Restarting rtmp session...") r.Log(Info, "Restarting rtmp session...")
@ -446,81 +432,92 @@ func (r *revid) outputClips() {
} }
r.Log(Debug, "Trying to send again with new connection...") r.Log(Debug, "Trying to send again with new connection...")
// and if the ring buffer is full then we flush the incoming data r.sendClip(chunk) // TODO(kortschak): Log these errors?
err2 = r.sendClip(clip)
} }
} }
chunk.Close() // ring.Chunk is an io.Closer, but Close alwats returns nil.
r.Log(Detail, "Done reading that clip from ringbuffer...") r.Log(Detail, "Done reading that clip from ringbuffer...")
// let the ringbuffer know that we're done with the memory we grabbed when
// we call ringBuffer.Get()
if err := r.ringBuffer.DoneReading(); err != nil {
r.Log(Error, err.Error())
}
// Log some information regarding bitrate and ring buffer size if it's time // Log some information regarding bitrate and ring buffer size if it's time
now = time.Now() now = time.Now()
deltaTime := now.Sub(prevTime) deltaTime := now.Sub(prevTime)
if deltaTime > time.Duration(bitrateTime)*time.Second { if deltaTime > time.Duration(bitrateTime)*time.Second {
r.currentBitrate = int64(float64(bytes*8) / float64(deltaTime/1e9)) r.currentBitrate = int64(float64(bytes*8) / float64(deltaTime/1e9))
r.Log(Debug, fmt.Sprintf("Bitrate: %v bits/s\n", r.currentBitrate)) r.Log(Debug, fmt.Sprintf("Bitrate: %v bits/s\n", r.currentBitrate))
r.Log(Debug, fmt.Sprintf("Ring buffer size: %v\n", r.ringBuffer.GetNoOfElements())) r.Log(Debug, fmt.Sprintf("Ring buffer size: %v\n", r.ringBuffer.Len()))
prevTime = now prevTime = now
bytes = 0 bytes = 0
} }
} }
}
r.Log(Info, "Not outputting clips anymore!") r.Log(Info, "Not outputting clips anymore!")
} }
// senClipToFile writes the passed clip to a file // senClipToFile writes the passed clip to a file
func (r *revid) sendClipToFile(clip []byte) error { func (r *revid) sendClipToFile(clip *ring.Chunk) error {
r.sendMutex.Lock() r.sendMutex.Lock()
defer r.sendMutex.Unlock() _, err := clip.WriteTo(r.outputFile)
_, err := r.outputFile.Write(clip) r.sendMutex.Unlock()
if err != nil {
return err return err
}
return nil
} }
// sendClipToHTTP takes a clip and an output url and posts through http. // sendClipToHTTP takes a clip and an output url and posts through http.
func (r *revid) sendClipToHTTP(clip []byte) error { func (r *revid) sendClipToHTTP(clip *ring.Chunk) error {
r.sendMutex.Lock()
defer r.sendMutex.Unlock() defer r.sendMutex.Unlock()
r.sendMutex.Lock()
timeout := time.Duration(httpTimeOut * time.Second) timeout := time.Duration(httpTimeOut * time.Second)
client := http.Client{Timeout: timeout} client := http.Client{Timeout: timeout}
url := r.config.HttpAddress + strconv.Itoa(len(clip)) url := r.config.HttpAddress + strconv.Itoa(clip.Len())
r.Log(Debug, fmt.Sprintf("Posting %s (%d bytes)\n", url, len(clip)))
resp, err := client.Post(url, "video/mp2t", bytes.NewReader(clip)) // FIXME(kortschak): This is necessary because Post takes
// an io.Reader as a parameter and closes it if it is an
// io.Closer (which *ring.Chunk is), ... and because we
// use a method value for dispatching the sendClip work.
// So to save work in this case, sendClip should be made
// a proper method with a behaviour switch based on a
// revid field so that we can prepare these bytes only
// once for each clip (reusing a buffer field? or tt
// might be work using a sync.Pool for the bodies).
post := bytes.NewBuffer(make([]byte, 0, clip.Len()))
_, err := clip.WriteTo(post)
if err != nil {
return fmt.Errorf("Error buffering: %v", err)
}
r.Log(Debug, fmt.Sprintf("Posting %s (%d bytes)\n", url, clip.Len()))
resp, err := client.Post(url, "video/mp2t", post)
if err != nil { if err != nil {
return fmt.Errorf("Error posting to %s: %s", url, err) return fmt.Errorf("Error posting to %s: %s", url, err)
} }
defer resp.Body.Close() defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body) body, err := ioutil.ReadAll(resp.Body)
if err == nil { if err == nil {
r.Log(Debug, fmt.Sprintf("%s\n", body)) r.Log(Debug, fmt.Sprintf("%s\n", body))
} else { } else {
r.Log(Error, err.Error()) r.Log(Error, err.Error())
} }
return nil return nil
} }
// sendClipToFfmpegRtmp sends the clip over the current rtmp connection using // sendClipToFfmpegRtmp sends the clip over the current rtmp connection using
// an ffmpeg process. // an ffmpeg process.
func (r *revid) sendClipToFfmpegRtmp(clip []byte) (err error) { func (r *revid) sendClipToFfmpegRtmp(clip *ring.Chunk) error {
r.sendMutex.Lock() r.sendMutex.Lock()
defer r.sendMutex.Unlock() _, err := clip.WriteTo(r.ffmpegStdin)
_, err = r.ffmpegStdin.Write(clip) r.sendMutex.Unlock()
return return err
} }
// sendClipToLibRtmp send the clip over the current rtmp connection using the // sendClipToLibRtmp send the clip over the current rtmp connection using the
// c based librtmp library // c based librtmp library
func (r *revid) sendClipToLibRtmp(clip []byte) (err error) { func (r *revid) sendClipToLibRtmp(clip *ring.Chunk) error {
r.sendMutex.Lock() r.sendMutex.Lock()
defer r.sendMutex.Unlock() _, err := clip.WriteTo(r.rtmpInst)
err = r.rtmpInst.Write(clip) r.sendMutex.Unlock()
return return err
} }
// setupOutputForFfmpegRtmp sets up output to rtmp using an ffmpeg process // setupOutputForFfmpegRtmp sets up output to rtmp using an ffmpeg process

6
ringbuffer/Readme.md → ring/README.md
View File

@ -1,14 +1,14 @@
# Readme # Readme
The package av provides ... Package ring provides a ring buffer of io.ReadWriters.
# Author # Author
Saxon Nelson-Milton <saxon.milton@gmail.com> Dan Kortschak <dan@ausocean.org>
# License # License
ringbuffer is Copyright (C) 2017 the Australian Ocean Lab (AusOcean) ring is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the under the terms of the GNU General Public License as published by the

277
ring/ring.go Normal file
View File

@ -0,0 +1,277 @@
/*
NAME
ring.go - a structure that encapsulates a Buffer datastructure with conccurency
functionality
DESCRIPTION
See Readme.md
AUTHOR
Dan Kortschak <dan@ausocean.org>
LICENSE
ring.go is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.
*/
// Package ring provides a ring buffer of io.ReadWriters.
package ring
import (
"errors"
"io"
"time"
)
var (
ErrTimeout = errors.New("ring: buffer cycle timeout")
ErrDropped = errors.New("ring: dropped old write")
ErrStall = errors.New("ring: unable to dump old write")
ErrTooLong = errors.New("ring: write to long for buffer element")
)
// Buffer implements a ring buffer.
//
// The buffer has a writable head and a readable tail with a queue from the head
// to the tail. Concurrent read a write operations are safe.
type Buffer struct {
head, tail *Chunk
full, empty chan *Chunk
timeout time.Duration
}
// NewBuffer returns a Buffer with len elements of the given size. The timeout
// parameter specifies how long a write operation will wait before failing with
// a temporary timeout error.
func NewBuffer(len, size int, timeout time.Duration) *Buffer {
if len <= 0 || size <= 0 {
return nil
}
b := Buffer{
full: make(chan *Chunk, len),
empty: make(chan *Chunk, len),
timeout: timeout,
}
for i := 0; i < len; i++ {
b.empty <- newChunk(make([]byte, 0, size))
}
return &b
}
// Len returns the number of full buffer elements.
func (b *Buffer) Len() int {
return len(b.full)
}
// Write writes the bytes in b to the next current or next available element of the ring buffer
// it returns the number of bytes written and any error.
// If no element can be gained within the timeout or stolen from the queue, ErrStall is returned
// and if the len(p) is greater than the buffer's element size, ErrTooLong is returned. If a
// write was successful but a previous write was dropped, ErrDropped is returned.
//
// Write is safe to use concurrently with Read, but may not be used concurrently with another
// write operation.
func (b *Buffer) Write(p []byte) (int, error) {
var dropped bool
if b.head == nil {
timer := time.NewTimer(b.timeout)
select {
case <-timer.C:
select {
case b.head = <-b.full:
b.head.reset()
dropped = true
default:
// This should never happen.
return 0, ErrStall
}
case b.head = <-b.empty:
timer.Stop()
}
}
if len(p) > b.head.cap() {
return 0, ErrTooLong
}
if len(p) > b.head.cap()-b.head.Len() {
b.full <- b.head
b.head = nil
return b.Write(p)
}
n, err := b.head.write(p)
if b.head.cap()-b.head.Len() == 0 {
b.full <- b.head
b.head = nil
}
if dropped && err == nil {
err = ErrDropped
}
return n, err
}
// Flush puts the currently writing element of the buffer into the queue for reading. Flush
// is idempotent.
//
// Flush is safe to use concurrently with Read, but may not be used concurrently with another
// another write operation.
func (b *Buffer) Flush() {
if b.head == nil {
return
}
b.full <- b.head
b.head = nil
}
// Close closes the buffer. The buffer may not be written to after a call to close, but can
// be drained by calls to Read.
//
// Flush is safe to use concurrently with Read, but may not be used concurrently with another
// another write operation.
func (b *Buffer) Close() error {
b.Flush()
close(b.full)
return nil
}
// Next gets the next element from the queue ready for reading, returning ErrTimeout if no
// element is available within the timeout. If the Buffer has been closed Next returns io.EOF.
//
// Is it the responsibility of the caller to close the returned Chunk.
//
// Next is safe to use concurrently with write operations, but may not be used concurrently with
// another Read call or Next call. A goroutine calling Next must not call Flush or Close.
func (b *Buffer) Next(timeout time.Duration) (*Chunk, error) {
if b.tail == nil {
timer := time.NewTimer(timeout)
var ok bool
select {
case <-timer.C:
return nil, ErrTimeout
case b.tail, ok = <-b.full:
timer.Stop()
if !ok {
return nil, io.EOF
}
}
}
b.tail.owner = b
return b.tail, nil
}
// Read reads bytes from the current tail of the ring buffer into p and returns the number of
// bytes read and any error.
//
// Read is safe to use concurrently with write operations, but may not be used concurrently with
// another Read call or Next call. A goroutine calling Read must not call Flush or Close.
func (b *Buffer) Read(p []byte) (int, error) {
if b.tail == nil {
return 0, io.EOF
}
n, err := b.tail.read(p)
if b.tail.Len() == 0 {
b.tail.reset()
b.empty <- b.tail
b.tail = nil
}
return n, err
}
// Chunk is a simplified version of byte buffer without the capacity to grow beyond the
// buffer's original cap, and a modified WriteTo method that allows multiple calls without
// consuming the buffered data.
type Chunk struct {
buf []byte
off int
owner *Buffer
}
func newChunk(buf []byte) *Chunk {
return &Chunk{buf: buf[:0]}
}
// Len returns the number of bytes held in the chunk.
func (b *Chunk) Len() int {
return len(b.buf) - b.off
}
func (b *Chunk) cap() int {
return cap(b.buf)
}
func (b *Chunk) reset() {
b.buf = b.buf[:0]
b.off = 0
}
func (b *Chunk) write(p []byte) (n int, err error) {
if len(p) > cap(b.buf)-len(b.buf) {
err = ErrTooLong
}
l := len(b.buf)
m := l + len(p)
if m > cap(b.buf) {
m = cap(b.buf)
}
b.buf = b.buf[:m]
n = copy(b.buf[l:], p)
return n, err
}
func (b *Chunk) read(p []byte) (n int, err error) {
if b.Len() <= 0 {
if len(p) == 0 {
return 0, nil
}
return 0, io.EOF
}
n = copy(p, b.buf[b.off:])
b.off += n
return n, nil
}
// WriteTo writes data to w until there's no more data to write or when an error occurs.
// The return value n is the number of bytes written. Any error encountered during the
// write is also returned. Repeated called to WriteTo will write the same data until
// the Chunk's Close method is called.
//
// WriteTo will panic if the Chunk has not been obtained through a call to Buffer.Next or
// has been closed. WriteTo must be used in the same goroutine as the call to Next.
func (b *Chunk) WriteTo(w io.Writer) (n int64, err error) {
if b.owner == nil || b.owner.tail != b {
panic("ring: invalid use of ring buffer chunk")
}
_n, err := w.Write(b.buf)
if _n > len(b.buf) {
panic("ring: invalid byte count")
}
if _n != len(b.buf) {
return int64(_n), io.ErrShortWrite
}
return int64(_n), nil
}
// Close closes the Chunk, reseting its data and releasing it back to the Buffer. A Chunk
// may not be used after it has been closed. Close must be used in the same goroutine as
// the call to Next.
func (b *Chunk) Close() error {
if b.owner == nil || b.owner.tail != b {
panic("ring: invalid use of ring buffer chunk")
}
b.reset()
b.owner.tail = nil
empty := b.owner.empty
b.owner = nil
empty <- b
return nil
}

489
ring/ring_test.go Normal file
View File

@ -0,0 +1,489 @@
/*
NAME
ring_test.go - a test suite adopting the golang testing library to test functionality of the
RingBuffer structure
DESCRIPTION
See README.md
AUTHOR
Dan Kortschak <dan@ausocean.org>
LICENSE
ring_test.go is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.
*/
package ring
import (
"bytes"
"io"
"io/ioutil"
"reflect"
"strings"
"sync"
"testing"
"time"
)
var roundTripTests = []struct {
name string
len int
size int
timeout time.Duration
nextTimeout time.Duration
data [][]string
readDelay time.Duration
writeDelay time.Duration
}{
{
name: "happy",
len: 2, size: 50,
timeout: 100 * time.Millisecond,
nextTimeout: 100 * time.Millisecond,
data: [][]string{
{"frame1", "frame2", "frame3", "frame4"},
{"frame5", "frame6"},
{"frame5", "frame6", "frame7"},
{"frame8", "frame9", "frame10"},
{"frame11"},
{"frame12", "frame13"},
{"frame14", "frame15", "frame16", "frame17"},
},
},
{
name: "slow write",
len: 2, size: 50,
timeout: 100 * time.Millisecond,
nextTimeout: 100 * time.Millisecond,
data: [][]string{
{"frame1", "frame2", "frame3", "frame4"},
{"frame5", "frame6"},
{"frame5", "frame6", "frame7"},
{"frame8", "frame9", "frame10"},
{"frame11"},
{"frame12", "frame13"},
{"frame14", "frame15", "frame16", "frame17"},
},
writeDelay: 500 * time.Millisecond,
},
{
name: "slow read",
len: 2, size: 50,
timeout: 100 * time.Millisecond,
nextTimeout: 100 * time.Millisecond,
data: [][]string{
{"frame1", "frame2", "frame3", "frame4"},
{"frame5", "frame6"},
{"frame5", "frame6", "frame7"},
{"frame8", "frame9", "frame10"},
{"frame11"},
{"frame12", "frame13"},
{"frame14", "frame15", "frame16", "frame17"},
},
readDelay: 500 * time.Millisecond,
},
}
func TestRoundTrip(t *testing.T) {
const maxTimeouts = 100
for _, test := range roundTripTests {
b := NewBuffer(test.len, test.size, test.timeout)
var wg sync.WaitGroup
wg.Add(2)
go func() {
defer wg.Done()
for _, c := range test.data {
var dropped int
for _, f := range c {
time.Sleep(test.writeDelay) // Simulate slow data capture.
_, err := b.Write([]byte(f))
switch err {
case nil:
dropped = 0
case ErrDropped:
if dropped > maxTimeouts {
t.Errorf("too many write drops for %q", test.name)
return
}
dropped++
default:
t.Errorf("unexpected write error for %q: %v", test.name, err)
return
}
}
b.Flush()
}
b.Close()
}()
go func() {
buf := make([]byte, 1<<10)
defer wg.Done()
var got []string
var timeouts int
elements:
for {
_, err := b.Next(test.nextTimeout)
switch err {
case nil:
timeouts = 0
case ErrTimeout:
if timeouts > maxTimeouts {
t.Errorf("too many timeouts for %q", test.name)
return
}
timeouts++
case io.EOF:
break elements
default:
t.Errorf("unexpected read error for %q: %v", test.name, err)
return
}
reads:
for {
n, err := b.Read(buf)
if n != 0 {
time.Sleep(test.readDelay) // Simulate slow data processing.
got = append(got, string(buf[:n]))
}
switch err {
case nil:
case io.EOF:
break reads
default:
t.Errorf("unexpected read error for %q: %v", test.name, err)
return
}
}
}
var want []string
for _, c := range test.data {
want = append(want, strings.Join(c, ""))
}
if test.readDelay == 0 {
if !reflect.DeepEqual(got, want) {
t.Errorf("unexpected round-trip result for %q:\ngot: %#v\nwant:%#v", test.name, got, want)
}
} else {
// We may have dropped writes in this case.
// So just check that we can consume every
// received element with reference to what
// was sent.
// TODO(kortschak): Check that the number of
// missing elements matches the number of
// dropped writes.
var sidx, ridx int
var recd string
for ridx, recd = range got {
for ; sidx < len(want); sidx++ {
if recd == want[sidx] {
break
}
}
}
if ridx != len(got)-1 {
t.Errorf("unexpected round-trip result for %q (unexplained element received):\ngot: %#v\nwant:%#v", test.name, got, want)
}
}
}()
wg.Wait()
}
}
func TestRoundTripWriterTo(t *testing.T) {
const maxTimeouts = 100
for _, test := range roundTripTests {
b := NewBuffer(test.len, test.size, test.timeout)
var wg sync.WaitGroup
wg.Add(2)
go func() {
defer wg.Done()
for _, c := range test.data {
var dropped int
for _, f := range c {
time.Sleep(test.writeDelay) // Simulate slow data capture.
_, err := b.Write([]byte(f))
switch err {
case nil:
dropped = 0
case ErrDropped:
if dropped > maxTimeouts {
t.Errorf("too many write drops for %q", test.name)
return
}
dropped++
default:
t.Errorf("unexpected write error for %q: %v", test.name, err)
return
}
}
b.Flush()
}
b.Close()
}()
go func() {
var buf bytes.Buffer
defer wg.Done()
var got []string
var timeouts int
elements:
for {
chunk, err := b.Next(test.nextTimeout)
switch err {
case nil:
timeouts = 0
case ErrTimeout:
if timeouts > maxTimeouts {
t.Errorf("too many timeouts for %q", test.name)
return
}
timeouts++
continue
case io.EOF:
break elements
default:
t.Errorf("unexpected read error for %q: %v", test.name, err)
return
}
n, err := chunk.WriteTo(&buf)
if n != 0 {
time.Sleep(test.readDelay) // Simulate slow data processing.
got = append(got, buf.String())
buf.Reset()
}
if err != nil {
t.Errorf("unexpected writeto error for %q: %v", test.name, err)
return
}
err = chunk.Close()
if err != nil {
t.Errorf("unexpected close error for %q: %v", test.name, err)
return
}
}
var want []string
for _, c := range test.data {
want = append(want, strings.Join(c, ""))
}
if test.readDelay == 0 {
if !reflect.DeepEqual(got, want) {
t.Errorf("unexpected round-trip result for %q:\ngot: %#v\nwant:%#v", test.name, got, want)
}
} else {
// We may have dropped writes in this case.
// So just check that we can consume every
// received element with reference to what
// was sent.
// TODO(kortschak): Check that the number of
// missing elements matches the number of
// dropped writes.
var sidx, ridx int
var recd string
for ridx, recd = range got {
for ; sidx < len(want); sidx++ {
if recd == want[sidx] {
break
}
}
}
if ridx != len(got)-1 {
t.Errorf("unexpected round-trip result for %q (unexplained element received):\ngot: %#v\nwant:%#v", test.name, got, want)
}
}
}()
wg.Wait()
}
}
func BenchmarkRoundTrip(b *testing.B) {
const (
maxTimeouts = 100
len = 50
size = 150e3
timeout = 10 * time.Millisecond
frameLen = 30e3
writeDelay = 20 * time.Millisecond
readDelay = 50 * time.Millisecond
)
// Allocated prior to timer reset since it is an
// amortised cost.
rb := NewBuffer(len, size, timeout)
var wg sync.WaitGroup
wg.Add(1)
go func() {
defer wg.Done()
var timeouts int
elements:
for {
_, err := rb.Next(timeout)
switch err {
case nil:
timeouts = 0
case ErrTimeout:
if timeouts > maxTimeouts {
b.Error("too many timeouts")
return
}
timeouts++
case io.EOF:
break elements
default:
b.Errorf("unexpected read error: %v", err)
return
}
_, err = ioutil.ReadAll(rb)
time.Sleep(readDelay) // Simulate slow data processing.
if err != nil {
b.Errorf("unexpected read error: %v", err)
return
}
}
}()
data := make([]byte, frameLen)
b.ResetTimer()
b.SetBytes(frameLen)
var dropped int
for i := 0; i < b.N; i++ {
time.Sleep(writeDelay) // Simulate slow data capture.
_, err := rb.Write(data)
switch err {
case nil:
dropped = 0
case ErrDropped:
if dropped > maxTimeouts {
b.Error("too many write drops")
return
}
dropped++
default:
b.Errorf("unexpected write error: %v", err)
return
}
}
rb.Close()
wg.Wait()
}
func BenchmarkRoundTripWriterTo(b *testing.B) {
const (
maxTimeouts = 100
len = 50
size = 150e3
timeout = 10 * time.Millisecond
frameLen = 30e3
writeDelay = 20 * time.Millisecond
readDelay = 50 * time.Millisecond
)
// Allocated prior to timer reset since it is an
// amortised cost.
rb := NewBuffer(len, size, timeout)
// This is hoisted here to ensure the allocation
// is not counted since this is outside the control
// of the ring buffer.
buf := bytes.NewBuffer(make([]byte, 0, size+1))
var wg sync.WaitGroup
wg.Add(1)
go func() {
defer wg.Done()
var timeouts int
elements:
for {
chunk, err := rb.Next(timeout)
switch err {
case nil:
timeouts = 0
case ErrTimeout:
if timeouts > maxTimeouts {
b.Error("too many timeouts")
return
}
timeouts++
continue
case io.EOF:
break elements
default:
b.Errorf("unexpected read error: %v", err)
return
}
n, err := chunk.WriteTo(buf)
if n != 0 {
time.Sleep(readDelay) // Simulate slow data processing.
buf.Reset()
}
if err != nil {
b.Errorf("unexpected writeto error: %v", err)
return
}
err = chunk.Close()
if err != nil {
b.Errorf("unexpected close error: %v", err)
return
}
}
}()
data := make([]byte, frameLen)
b.ResetTimer()
b.SetBytes(frameLen)
var dropped int
for i := 0; i < b.N; i++ {
time.Sleep(writeDelay) // Simulate slow data capture.
_, err := rb.Write(data)
switch err {
case nil:
dropped = 0
case ErrDropped:
if dropped > maxTimeouts {
b.Error("too many write drops")
return
}
dropped++
default:
b.Errorf("unexpected write error: %v", err)
return
}
}
rb.Close()
wg.Wait()
}

209
ringbuffer/RingBuffer.go
View File

@ -1,209 +0,0 @@
/*
NAME
RingBuffer.go - a structure that encapsulates a RingBuffer datastructure with conccurency
functionality
DESCRIPTION
See Readme.md
AUTHOR
Saxon Nelson-Milton <saxon.milton@gmail.com>
LICENSE
RingBuffer.go is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with revid in gpl.txt. If not, see [GNU licenses](http://www.gnu.org/licenses).
*/
package ringbuffer
import (
"errors"
"sync"
)
/*
RingBuffer aims to provide functionality of a RingBuffer data structure.
It may be used in concurrent routines.
*/
type RingBuffer interface {
Get() ([]byte, error)
DoneWriting(size int) error
Read() ([]byte, error)
DoneReading() error
IsReadable() bool
IsWritable() bool
GetNoOfElements() int
Full() bool
}
func (rb *ringBuffer) GetNoOfElements() int {
return rb.noOfElements
}
// ringBuffer implements the RingBuffer interface
type ringBuffer struct {
dataMemory [][]byte
sizeMemory []int
size int
noOfElements int
first int
last int
currentlyWriting bool
currentlyReading bool
mutex sync.Mutex
full bool
}
/*
New returns a pointer to a newly allocated RingBuffer with the parameters specified.
It initialises fields and allocates the required dataMemory.
*/
func NewRingBuffer(bufferSize int, elementSize int) (rb *ringBuffer) {
if bufferSize <= 0 || elementSize <= 0 {
return nil
}
rb = new(ringBuffer)
rb.dataMemory = make([][]byte, bufferSize)
for i := range rb.dataMemory {
rb.dataMemory[i] = make([]byte, elementSize)
}
rb.sizeMemory = make([]int, bufferSize)
rb.size = bufferSize
rb.noOfElements = 0
rb.first = -1
rb.last = -1
rb.currentlyWriting = false
rb.currentlyReading = false
rb.mutex = sync.Mutex{}
rb.full = false
return
}
/*
Get provides the address to the next empty element in the RingBuffer.
An error is returned if the buffer is full, or there has already been
a call to Get without an accompanying call to DoneWriting.
*/
func (rb *ringBuffer) Get() ([]byte, error) {
rb.mutex.Lock()
defer rb.mutex.Unlock()
if !rb.IsWritable() {
rb.full = true
return nil, errors.New("Buffer full!")
}
rb.full = false
var nextlast int
if !rb.currentlyWriting {
rb.currentlyWriting = true
nextlast = rb.last + 1
if nextlast == rb.size {
nextlast = 0
}
} else {
nextlast = rb.last
}
return rb.dataMemory[nextlast], nil
}
/*
DoneWriting let's the RingBuffer know that we have finished writing to the
address recieved by a call to Get, and also let's the buffer know how much
data was written. An Error is thrown if there was not an initial call to Get.
*/
func (rb *ringBuffer) DoneWriting(size int) error {
rb.mutex.Lock()
defer rb.mutex.Unlock()
if !rb.currentlyWriting {
return errors.New("DoneWriting called without initial call to Get!")
}
if rb.first == -1 {
rb.first++
}
rb.last++
if rb.last == rb.size {
rb.last = 0
}
rb.sizeMemory[rb.last] = size
rb.noOfElements++
rb.currentlyWriting = false
return nil
}
/*
Read returns a slice containing the next element in the ring buffer and
thereafter considers it empty and can be used for latter writing. The address
of the data is returned, as well as the size of the data contained at this
address. An error is returned if the buffer is empty, or there has been a
second call to Read before a call to DoneReading.
*/
func (rb *ringBuffer) Read() ([]byte, error) {
rb.mutex.Lock()
defer rb.mutex.Unlock()
if !rb.IsReadable() {
return nil, errors.New("Buffer is empty, nothing to read!")
}
if rb.currentlyReading {
return nil, errors.New("Second call to Read! Call DoneReading first!")
}
rb.currentlyReading = true
return rb.dataMemory[rb.first][:rb.sizeMemory[rb.first]], nil
}
/*
DoneReading informs the buffer that we have finished with the address
provided by Read. The buffer can now consider this address to be empty.
An error is returned if there was no initial call to Read.
*/
func (rb *ringBuffer) DoneReading() error {
rb.mutex.Lock()
defer rb.mutex.Unlock()
if !rb.currentlyReading {
return errors.New("DoneReading called but no initial call to Read!")
}
rb.first++
if rb.first == rb.size {
rb.first = 0
}
rb.noOfElements--
rb.currentlyReading = false
return nil
}
func (rb *ringBuffer) Full() bool {
return rb.full
}
/*
IsReadable returns true if it is possible to read from the buffer, i.e. if
it is not empty.
*/
func (rb *ringBuffer) IsReadable() bool {
if rb.first == -1 || rb.noOfElements == 0 {
return false
}
return true
}
/*
IsWritable returns true if it is possible to write to the buffer, i.e. if
it is not full.
*/
func (rb *ringBuffer) IsWritable() bool {
if rb.noOfElements == rb.size {
return false
}
return true
}

178
ringbuffer/RingBuffer_test.go
View File

@ -1,178 +0,0 @@
/*
NAME
RingBuffer_test.go - a test suite adopting the golang testing library to test functionality of the
RingBuffer structure
DESCRIPTION
See Readme.md
AUTHOR
Saxon Nelson-Milton <saxon.milton@gmail.com>
LICENSE
RingBuffer_test.go is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with revid in gpl.txt. If not, see [GNU licenses](http://www.gnu.org/licenses).
*/
package ringbuffer
import (
"fmt"
"testing"
"time"
)
// Parameters used over the testing
const (
testBufferSize = 10
testElementSize = 1
testOverFlowSize = 2
testDataSize = 1
testConcurrencyBufferSize = 1000
)
// Types of actions, assertions and test ends
const (
testWrite = 0
testDoneWriting = 1
testRead = 2
testDoneReading = 3
testEnd = 4
assertNoError = 5
assertError = 6
)
// Strings to help with test fail messages
const (
noErrorFailMessage = "Should have got error!"
falseErrorFailMessage = "Should not have got error: %v"
atMessage = " Series: %v"
)
// Pointer to the ringbuffer we will be testing
var rb *ringBuffer
// Call when the a test array has the wrong format
func wrongFmt() {
fmt.Println("Test has wrong format!")
}
// Test that the Make method correctly allocates memory for arbitrary buffer
// size of 10 and arbitrary element size of 10
func TestMake(t *testing.T) {
rb = NewRingBuffer(testBufferSize, testElementSize)
if len(rb.dataMemory) != testBufferSize {
t.Errorf("Len of buffer is wrong!")
}
if len(rb.dataMemory[0]) != testElementSize {
t.Errorf("Len of individual element is wrong!")
}
}
// Format: { <size of uffer>, <type of check>, <action>, ..., <action>, <test end> }
var tests = [][]int{
{testBufferSize, assertError, testDoneWriting, testEnd},
{testBufferSize, assertNoError, testWrite, testDoneWriting, testEnd},
{testBufferSize, assertError, testDoneReading, testEnd},
{testBufferSize, assertError, testRead, testEnd},
{testBufferSize, assertError, testWrite, testWrite, testEnd},
{testBufferSize, assertNoError, testWrite, testDoneWriting, testRead,
testDoneReading, testEnd},
{testBufferSize, assertNoError, testWrite, testDoneWriting, testWrite,
testDoneWriting, testRead, testDoneReading, testRead, testDoneReading,
testEnd},
{testBufferSize, assertError, testWrite, testDoneWriting, testRead,
testDoneReading, testRead, testDoneReading, testEnd},
{testOverFlowSize, assertError, testWrite, testDoneWriting, testWrite, testDoneWriting,
testWrite, testDoneWriting, testEnd},
{testOverFlowSize, assertNoError, testWrite, testDoneWriting, testWrite, testDoneWriting,
testRead, testDoneReading, testWrite, testDoneWriting, testEnd},
{testOverFlowSize, assertError, testWrite, testDoneWriting, testWrite, testDoneWriting,
testRead, testDoneReading, testWrite, testDoneWriting, testWrite,
testDoneWriting, testEnd},
{testBufferSize, assertError, testWrite, testDoneWriting, testWrite,
testDoneWriting, testRead, testRead, testEnd},
}
// Tests series of actions performed by the ring buffer defined in array tests
func TestAllSorts(t *testing.T) {
for i := range tests {
rb = NewRingBuffer(tests[i][0], testElementSize)
var err error
for j := 2; tests[i][j] != testEnd; j++ {
var newErr error
switch tests[i][j] {
case testWrite:
_, newErr = rb.Get()
case testDoneWriting:
newErr = rb.DoneWriting(testDataSize)
case testRead:
_, newErr = rb.Read()
case testDoneReading:
newErr = rb.DoneReading()
default:
wrongFmt()
}
if err == nil {
err = newErr
}
}
switch tests[i][1] {
case assertError:
if err == nil {
t.Errorf(noErrorFailMessage+atMessage, i)
}
case assertNoError:
if err != nil {
t.Errorf(falseErrorFailMessage+atMessage, err, i)
}
default:
wrongFmt()
}
}
}
// Let's see if we can do concurrency. (tip: run as: go test -race) to see
// any data race issues. We will continously write and read at concurrently
// time for a second
func TestConcurrency1(t *testing.T) {
rb = NewRingBuffer(testConcurrencyBufferSize, testElementSize)
go func() {
for i := 0; i < 100; i++ {
if data, err1 := rb.Read(); data != nil {
err2 := rb.DoneReading()
if err1 != nil {
t.Errorf(falseErrorFailMessage, err1)
}
if err2 != nil {
t.Errorf(falseErrorFailMessage, err2)
}
}
}
}()
go func() {
for i := 0; i < 100; i++ {
_, err1 := rb.Get()
err2 := rb.DoneWriting(testDataSize)
if err1 != nil {
t.Errorf(falseErrorFailMessage, err1)
}
if err2 != nil {
t.Errorf(falseErrorFailMessage, err2)
}
}
}()
time.Sleep(1000 * time.Millisecond)
}

674
ringbuffer/gpl.txt
View File

@ -1,674 +0,0 @@
GNU GENERAL PUBLIC LICENSE
Version 3, 29 June 2007
Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
The GNU General Public License is a free, copyleft license for
software and other kinds of works.
The licenses for most software and other practical works are designed
to take away your freedom to share and change the works. By contrast,
the GNU General Public License is intended to guarantee your freedom to
share and change all versions of a program--to make sure it remains free
software for all its users. We, the Free Software Foundation, use the
GNU General Public License for most of our software; it applies also to
any other work released this way by its authors. You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
them if you wish), that you receive source code or can get it if you
want it, that you can change the software or use pieces of it in new
free programs, and that you know you can do these things.
To protect your rights, we need to prevent others from denying you
these rights or asking you to surrender the rights. Therefore, you have
certain responsibilities if you distribute copies of the software, or if
you modify it: responsibilities to respect the freedom of others.
For example, if you distribute copies of such a program, whether
gratis or for a fee, you must pass on to the recipients the same
freedoms that you received. You must make sure that they, too, receive
or can get the source code. And you must show them these terms so they
know their rights.
Developers that use the GNU GPL protect your rights with two steps:
(1) assert copyright on the software, and (2) offer you this License
giving you legal permission to copy, distribute and/or modify it.
For the developers' and authors' protection, the GPL clearly explains
that there is no warranty for this free software. For both users' and
authors' sake, the GPL requires that modified versions be marked as
changed, so that their problems will not be attributed erroneously to
authors of previous versions.
Some devices are designed to deny users access to install or run
modified versions of the software inside them, although the manufacturer
can do so. This is fundamentally incompatible with the aim of
protecting users' freedom to change the software. The systematic
pattern of such abuse occurs in the area of products for individuals to
use, which is precisely where it is most unacceptable. Therefore, we
have designed this version of the GPL to prohibit the practice for those
products. If such problems arise substantially in other domains, we
stand ready to extend this provision to those domains in future versions
of the GPL, as needed to protect the freedom of users.
Finally, every program is threatened constantly by software patents.
States should not allow patents to restrict development and use of
software on general-purpose computers, but in those that do, we wish to
avoid the special danger that patents applied to a free program could
make it effectively proprietary. To prevent this, the GPL assures that
patents cannot be used to render the program non-free.
The precise terms and conditions for copying, distribution and
modification follow.
TERMS AND CONDITIONS
0. Definitions.
"This License" refers to version 3 of the GNU General Public License.
"Copyright" also means copyright-like laws that apply to other kinds of
works, such as semiconductor masks.
"The Program" refers to any copyrightable work licensed under this
License. Each licensee is addressed as "you". "Licensees" and
"recipients" may be individuals or organizations.
To "modify" a work means to copy from or adapt all or part of the work
in a fashion requiring copyright permission, other than the making of an
exact copy. The resulting work is called a "modified version" of the
earlier work or a work "based on" the earlier work.
A "covered work" means either the unmodified Program or a work based
on the Program.
To "propagate" a work means to do anything with it that, without
permission, would make you directly or secondarily liable for
infringement under applicable copyright law, except executing it on a
computer or modifying a private copy. Propagation includes copying,
distribution (with or without modification), making available to the
public, and in some countries other activities as well.
To "convey" a work means any kind of propagation that enables other
parties to make or receive copies. Mere interaction with a user through
a computer network, with no transfer of a copy, is not conveying.
An interactive user interface displays "Appropriate Legal Notices"
to the extent that it includes a convenient and prominently visible
feature that (1) displays an appropriate copyright notice, and (2)
tells the user that there is no warranty for the work (except to the
extent that warranties are provided), that licensees may convey the
work under this License, and how to view a copy of this License. If
the interface presents a list of user commands or options, such as a
menu, a prominent item in the list meets this criterion.
1. Source Code.
The "source code" for a work means the preferred form of the work
for making modifications to it. "Object code" means any non-source
form of a work.
A "Standard Interface" means an interface that either is an official
standard defined by a recognized standards body, or, in the case of
interfaces specified for a particular programming language, one that
is widely used among developers working in that language.
The "System Libraries" of an executable work include anything, other
than the work as a whole, that (a) is included in the normal form of
packaging a Major Component, but which is not part of that Major
Component, and (b) serves only to enable use of the work with that
Major Component, or to implement a Standard Interface for which an
implementation is available to the public in source code form. A
"Major Component", in this context, means a major essential component
(kernel, window system, and so on) of the specific operating system
(if any) on which the executable work runs, or a compiler used to
produce the work, or an object code interpreter used to run it.
The "Corresponding Source" for a work in object code form means all
the source code needed to generate, install, and (for an executable
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programs which are used unmodified in performing those activities but
which are not part of the work. For example, Corresponding Source
includes interface definition files associated with source files for
the work, and the source code for shared libraries and dynamically
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such as by intimate data communication or control flow between those
subprograms and other parts of the work.
The Corresponding Source need not include anything that users
can regenerate automatically from other parts of the Corresponding
Source.
The Corresponding Source for a work in source code form is that
same work.
2. Basic Permissions.
All rights granted under this License are granted for the term of
copyright on the Program, and are irrevocable provided the stated
conditions are met. This License explicitly affirms your unlimited
permission to run the unmodified Program. The output from running a
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rights of fair use or other equivalent, as provided by copyright law.
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10
rtmp/rtmp.go
View File

@ -49,7 +49,7 @@ import (
// Session provides an interface for sending flv tags over rtmp. // Session provides an interface for sending flv tags over rtmp.
type Session interface { type Session interface {
StartSession() error StartSession() error
Write([]byte) error Write([]byte) (int, error)
Close() error Close() error
} }
@ -85,14 +85,14 @@ func (s *session) StartSession() error {
} }
// Write writes a frame (flv tag) to the rtmp connection // Write writes a frame (flv tag) to the rtmp connection
func (s *session) Write(data []byte) error { func (s *session) Write(data []byte) (int, error) {
if s.rtmp == nil { if s.rtmp == nil {
return errors.New("rtmp: attempt to write to non-running session") return 0, errors.New("rtmp: attempt to write to non-running session")
} }
if C.write_frame(s.rtmp, (*C.char)(unsafe.Pointer(&data[0])), C.uint(len(data))) != 0 { if C.write_frame(s.rtmp, (*C.char)(unsafe.Pointer(&data[0])), C.uint(len(data))) != 0 {
return errors.New("RTMP write error! Check rtmp log for details!") return 0, errors.New("RTMP write error! Check rtmp log for details!")
} }
return nil return len(data), nil
} }
// Close terminates the rtmp connection // Close terminates the rtmp connection