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livetrax/libs/rubberband/src/RingBuffer.h
Paul Davis 7da75446b8 add (copy of 2.0-ongoing) rubberband to 3.0
git-svn-id: svn://localhost/ardour2/branches/3.0@3713 d708f5d6-7413-0410-9779-e7cbd77b26cf
2008-09-10 21:35:32 +00:00

671 lines
17 KiB
C++

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
/*
Rubber Band
An audio time-stretching and pitch-shifting library.
Copyright 2007-2008 Chris Cannam.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version. See the file
COPYING included with this distribution for more information.
*/
#ifndef _RUBBERBAND_RINGBUFFER_H_
#define _RUBBERBAND_RINGBUFFER_H_
#include <cstring>
#include <sys/types.h>
#include <cstring>
#ifndef _WIN32
#include <sys/mman.h>
#endif
#include "Scavenger.h"
#include "Profiler.h"
//#define DEBUG_RINGBUFFER 1
#ifdef _WIN32
#define MLOCK(a,b) 1
#define MUNLOCK(a,b) 1
#else
#define MLOCK(a,b) ::mlock(a,b)
#define MUNLOCK(a,b) ::munlock(a,b)
#endif
#ifdef DEBUG_RINGBUFFER
#include <iostream>
#endif
namespace RubberBand {
/**
* RingBuffer implements a lock-free ring buffer for one writer and N
* readers, that is to be used to store a sample type T.
*/
template <typename T, int N = 1>
class RingBuffer
{
public:
/**
* Create a ring buffer with room to write n samples.
*
* Note that the internal storage size will actually be n+1
* samples, as one element is unavailable for administrative
* reasons. Since the ring buffer performs best if its size is a
* power of two, this means n should ideally be some power of two
* minus one.
*/
RingBuffer(int n);
virtual ~RingBuffer();
/**
* Return the total capacity of the ring buffer in samples.
* (This is the argument n passed to the constructor.)
*/
int getSize() const;
/**
* Resize the ring buffer. This also empties it; use resized()
* below if you do not want this to happen. Actually swaps in a
* new, larger buffer; the old buffer is scavenged after a seemly
* delay. Should be called from the write thread.
*/
void resize(int newSize);
/**
* Return a new ring buffer (allocated with "new" -- called must
* delete when no longer needed) of the given size, containing the
* same data as this one. If another thread reads from or writes
* to this buffer during the call, the results may be incomplete
* or inconsistent. If this buffer's data will not fit in the new
* size, the contents are undefined.
*/
RingBuffer<T, N> *resized(int newSize, int R = 0) const;
/**
* Lock the ring buffer into physical memory. Returns true
* for success.
*/
bool mlock();
/**
* Reset read and write pointers, thus emptying the buffer.
* Should be called from the write thread.
*/
void reset();
/**
* Return the amount of data available for reading by reader R, in
* samples.
*/
int getReadSpace(int R = 0) const;
/**
* Return the amount of space available for writing, in samples.
*/
int getWriteSpace() const;
/**
* Read n samples from the buffer, for reader R. If fewer than n
* are available, the remainder will be zeroed out. Returns the
* number of samples actually read.
*/
int read(T *R__ destination, int n, int R = 0);
/**
* Read n samples from the buffer, for reader R, adding them to
* the destination. If fewer than n are available, the remainder
* will be left alone. Returns the number of samples actually
* read.
*/
int readAdding(T *R__ destination, int n, int R = 0);
/**
* Read one sample from the buffer, for reader R. If no sample is
* available, this will silently return zero. Calling this
* repeatedly is obviously slower than calling read once, but it
* may be good enough if you don't want to allocate a buffer to
* read into.
*/
T readOne(int R = 0);
/**
* Read n samples from the buffer, if available, for reader R,
* without advancing the read pointer -- i.e. a subsequent read()
* or skip() will be necessary to empty the buffer. If fewer than
* n are available, the remainder will be zeroed out. Returns the
* number of samples actually read.
*/
int peek(T *R__ destination, int n, int R = 0) const;
/**
* Read one sample from the buffer, if available, without
* advancing the read pointer -- i.e. a subsequent read() or
* skip() will be necessary to empty the buffer. Returns zero if
* no sample was available.
*/
T peekOne(int R = 0) const;
/**
* Pretend to read n samples from the buffer, for reader R,
* without actually returning them (i.e. discard the next n
* samples). Returns the number of samples actually available for
* discarding.
*/
int skip(int n, int R = 0);
/**
* Write n samples to the buffer. If insufficient space is
* available, not all samples may actually be written. Returns
* the number of samples actually written.
*/
int write(const T *source, int n);
/**
* Write n zero-value samples to the buffer. If insufficient
* space is available, not all zeros may actually be written.
* Returns the number of zeroes actually written.
*/
int zero(int n);
protected:
T *R__ m_buffer;
volatile int m_writer;
volatile int m_readers[N];
int m_size;
bool m_mlocked;
static Scavenger<ScavengerArrayWrapper<T> > m_scavenger;
private:
RingBuffer(const RingBuffer &); // not provided
RingBuffer &operator=(const RingBuffer &); // not provided
};
template <typename T, int N>
Scavenger<ScavengerArrayWrapper<T> > RingBuffer<T, N>::m_scavenger;
template <typename T, int N>
RingBuffer<T, N>::RingBuffer(int n) :
m_buffer(new T[n + 1]),
m_writer(0),
m_size(n + 1),
m_mlocked(false)
{
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::RingBuffer(" << n << ")" << std::endl;
#endif
for (int i = 0; i < N; ++i) m_readers[i] = 0;
m_scavenger.scavenge();
}
template <typename T, int N>
RingBuffer<T, N>::~RingBuffer()
{
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::~RingBuffer" << std::endl;
#endif
if (m_mlocked) {
MUNLOCK((void *)m_buffer, m_size * sizeof(T));
}
delete[] m_buffer;
m_scavenger.scavenge();
}
template <typename T, int N>
int
RingBuffer<T, N>::getSize() const
{
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::getSize(): " << m_size-1 << std::endl;
#endif
return m_size - 1;
}
template <typename T, int N>
void
RingBuffer<T, N>::resize(int newSize)
{
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::resize(" << newSize << ")" << std::endl;
#endif
m_scavenger.scavenge();
if (m_mlocked) {
MUNLOCK((void *)m_buffer, m_size * sizeof(T));
}
m_scavenger.claim(new ScavengerArrayWrapper<T>(m_buffer));
reset();
m_buffer = new T[newSize + 1];
m_size = newSize + 1;
if (m_mlocked) {
if (MLOCK((void *)m_buffer, m_size * sizeof(T))) {
m_mlocked = false;
}
}
}
template <typename T, int N>
RingBuffer<T, N> *
RingBuffer<T, N>::resized(int newSize, int R) const
{
RingBuffer<T, N> *newBuffer = new RingBuffer<T, N>(newSize);
int w = m_writer;
int r = m_readers[R];
while (r != w) {
T value = m_buffer[r];
newBuffer->write(&value, 1);
if (++r == m_size) r = 0;
}
return newBuffer;
}
template <typename T, int N>
bool
RingBuffer<T, N>::mlock()
{
if (MLOCK((void *)m_buffer, m_size * sizeof(T))) return false;
m_mlocked = true;
return true;
}
template <typename T, int N>
void
RingBuffer<T, N>::reset()
{
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::reset" << std::endl;
#endif
m_writer = 0;
for (int i = 0; i < N; ++i) m_readers[i] = 0;
}
template <typename T, int N>
int
RingBuffer<T, N>::getReadSpace(int R) const
{
int writer = m_writer;
int reader = m_readers[R];
int space;
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::getReadSpace(" << R << "): reader " << reader << ", writer " << writer << std::endl;
#endif
if (writer > reader) space = writer - reader;
else if (writer < reader) space = (writer + m_size) - reader;
else space = 0;
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::getReadSpace(" << R << "): " << space << std::endl;
#endif
return space;
}
template <typename T, int N>
int
RingBuffer<T, N>::getWriteSpace() const
{
int space = 0;
for (int i = 0; i < N; ++i) {
int writer = m_writer;
int reader = m_readers[i];
int here = (reader + m_size - writer - 1);
if (here >= m_size) here -= m_size;
if (i == 0 || here < space) space = here;
}
#ifdef DEBUG_RINGBUFFER
int rs(getReadSpace()), rp(m_readers[0]);
std::cerr << "RingBuffer: write space " << space << ", read space "
<< rs << ", total " << (space + rs) << ", m_size " << m_size << std::endl;
std::cerr << "RingBuffer: reader " << rp << ", writer " << m_writer << std::endl;
#endif
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::getWriteSpace(): " << space << std::endl;
#endif
return space;
}
template <typename T, int N>
int
RingBuffer<T, N>::read(T *R__ destination, int n, int R)
{
Profiler profiler("RingBuffer::read");
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::read(dest, " << n << ", " << R << ")" << std::endl;
#endif
int available = getReadSpace(R);
if (n > available) {
#ifdef DEBUG_RINGBUFFER
std::cerr << "WARNING: Only " << available << " samples available"
<< std::endl;
#endif
for (int i = available; i < n; ++i) {
destination[i] = 0;
}
n = available;
}
if (n == 0) return n;
int reader = m_readers[R];
int here = m_size - reader;
T *const R__ bufbase = m_buffer + reader;
if (here >= n) {
for (int i = 0; i < n; ++i) {
destination[i] = bufbase[i];
}
} else {
for (int i = 0; i < here; ++i) {
destination[i] = bufbase[i];
}
T *const R__ destbase = destination + here;
const int nh = n - here;
for (int i = 0; i < nh; ++i) {
destbase[i] = m_buffer[i];
}
}
reader += n;
while (reader >= m_size) reader -= m_size;
m_readers[R] = reader;
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::read: read " << n << ", reader now " << m_readers[R] << std::endl;
#endif
return n;
}
template <typename T, int N>
int
RingBuffer<T, N>::readAdding(T *R__ destination, int n, int R)
{
Profiler profiler("RingBuffer::readAdding");
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::readAdding(dest, " << n << ", " << R << ")" << std::endl;
#endif
int available = getReadSpace(R);
if (n > available) {
#ifdef DEBUG_RINGBUFFER
std::cerr << "WARNING: Only " << available << " samples available"
<< std::endl;
#endif
n = available;
}
if (n == 0) return n;
int reader = m_readers[R];
int here = m_size - reader;
const T *const R__ bufbase = m_buffer + reader;
if (here >= n) {
for (int i = 0; i < n; ++i) {
destination[i] += bufbase[i];
}
} else {
for (int i = 0; i < here; ++i) {
destination[i] += bufbase[i];
}
T *const R__ destbase = destination + here;
const int nh = n - here;
for (int i = 0; i < nh; ++i) {
destbase[i] += m_buffer[i];
}
}
reader += n;
while (reader >= m_size) reader -= m_size;
m_readers[R] = reader;
return n;
}
template <typename T, int N>
T
RingBuffer<T, N>::readOne(int R)
{
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::readOne(" << R << ")" << std::endl;
#endif
if (m_writer == m_readers[R]) {
#ifdef DEBUG_RINGBUFFER
std::cerr << "WARNING: No sample available"
<< std::endl;
#endif
return 0;
}
int reader = m_readers[R];
T value = m_buffer[reader];
if (++reader == m_size) reader = 0;
m_readers[R] = reader;
return value;
}
template <typename T, int N>
int
RingBuffer<T, N>::peek(T *R__ destination, int n, int R) const
{
Profiler profiler("RingBuffer::peek");
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::peek(dest, " << n << ", " << R << ")" << std::endl;
#endif
int available = getReadSpace(R);
if (n > available) {
#ifdef DEBUG_RINGBUFFER
std::cerr << "WARNING: Only " << available << " samples available"
<< std::endl;
#endif
memset(destination + available, 0, (n - available) * sizeof(T));
n = available;
}
if (n == 0) return n;
int reader = m_readers[R];
int here = m_size - reader;
const T *const R__ bufbase = m_buffer + reader;
if (here >= n) {
for (int i = 0; i < n; ++i) {
destination[i] = bufbase[i];
}
} else {
for (int i = 0; i < here; ++i) {
destination[i] = bufbase[i];
}
T *const R__ destbase = destination + here;
const int nh = n - here;
for (int i = 0; i < nh; ++i) {
destbase[i] = m_buffer[i];
}
}
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::peek: read " << n << std::endl;
#endif
return n;
}
template <typename T, int N>
T
RingBuffer<T, N>::peekOne(int R) const
{
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::peek(" << R << ")" << std::endl;
#endif
if (m_writer == m_readers[R]) {
#ifdef DEBUG_RINGBUFFER
std::cerr << "WARNING: No sample available"
<< std::endl;
#endif
return 0;
}
T value = m_buffer[m_readers[R]];
return value;
}
template <typename T, int N>
int
RingBuffer<T, N>::skip(int n, int R)
{
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::skip(" << n << ", " << R << ")" << std::endl;
#endif
int available = getReadSpace(R);
if (n > available) {
#ifdef DEBUG_RINGBUFFER
std::cerr << "WARNING: Only " << available << " samples available"
<< std::endl;
#endif
n = available;
}
if (n == 0) return n;
int reader = m_readers[R];
reader += n;
while (reader >= m_size) reader -= m_size;
m_readers[R] = reader;
return n;
}
template <typename T, int N>
int
RingBuffer<T, N>::write(const T *source, int n)
{
Profiler profiler("RingBuffer::write");
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::write(" << n << ")" << std::endl;
#endif
int available = getWriteSpace();
if (n > available) {
#ifdef DEBUG_RINGBUFFER
std::cerr << "WARNING: Only room for " << available << " samples"
<< std::endl;
#endif
n = available;
}
if (n == 0) return n;
int writer = m_writer;
int here = m_size - writer;
T *const R__ bufbase = m_buffer + writer;
if (here >= n) {
for (int i = 0; i < n; ++i) {
bufbase[i] = source[i];
}
} else {
for (int i = 0; i < here; ++i) {
bufbase[i] = source[i];
}
const int nh = n - here;
const T *const R__ srcbase = source + here;
T *const R__ buf = m_buffer;
for (int i = 0; i < nh; ++i) {
buf[i] = srcbase[i];
}
}
writer += n;
while (writer >= m_size) writer -= m_size;
m_writer = writer;
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::write: wrote " << n << ", writer now " << m_writer << std::endl;
#endif
return n;
}
template <typename T, int N>
int
RingBuffer<T, N>::zero(int n)
{
Profiler profiler("RingBuffer::zero");
#ifdef DEBUG_RINGBUFFER
std::cerr << "RingBuffer<T," << N << ">[" << this << "]::zero(" << n << ")" << std::endl;
#endif
int available = getWriteSpace();
if (n > available) {
#ifdef DEBUG_RINGBUFFER
std::cerr << "WARNING: Only room for " << available << " samples"
<< std::endl;
#endif
n = available;
}
if (n == 0) return n;
int writer = m_writer;
int here = m_size - writer;
T *const R__ bufbase = m_buffer + writer;
if (here >= n) {
for (int i = 0; i < n; ++i) {
bufbase[i] = 0;
}
} else {
for (int i = 0; i < here; ++i) {
bufbase[i] = 0;
}
const int nh = n - here;
for (int i = 0; i < nh; ++i) {
m_buffer[i] = 0;
}
}
writer += n;
while (writer >= m_size) writer -= m_size;
m_writer = writer;
#ifdef DEBUG_RINGBUFFER
std::cerr << "writer -> " << m_writer << std::endl;
#endif
return n;
}
}
//#include "RingBuffer.cpp"
#endif // _RINGBUFFER_H_