ringbuffer.cpp

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/*
 * ringbuffer.c
 *        
 *
 * Copyright (C) 2003 Marcus Metzler <mocm@metzlerbros.de>
 *                    Metzler Brothers Systementwicklung GbR
 * Changes to use MythTV logging
 * Copyright (C) 2011 Gavin Hurlbut <ghurlbut@mythtv.org>
 *
 * 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.
 *
 *
 * This program 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
 * General Public License for more details.
 *
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 * Or, point your browser to http://www.gnu.org/copyleft/gpl.html
 *
 */
 
#include <cstdlib>
#include <cstring>
#include "ringbuffer.h"
#include "pes.h"
 
#include "libmythbase/mythlogging.h"
 
#define DEBUG true
 
int ring_init (ringbuffer *rbuf, int size)
{
        if (size > 0){
                rbuf->size = size;
                rbuf->buffer = (uint8_t *) malloc(sizeof(uint8_t)*size);
                if (rbuf->buffer == nullptr)
                {
                        LOG(VB_GENERAL, LOG_ERR,
                            "Not enough memory for ringbuffer");
                        return -1;
                }
        } else {
                LOG(VB_GENERAL, LOG_ERR, "Wrong size for ringbuffer");
                return -1;
        }
        rbuf->read_pos = 0;     
        rbuf->write_pos = 0;
        return 0;
}
 
int ring_reinit (ringbuffer *rbuf, int size)
{
        if (size > (int)(rbuf->size)) {
                auto *tmpalloc = (uint8_t *) realloc(rbuf->buffer,
                                                        sizeof(uint8_t)*size);
                if (! tmpalloc)
                        return -1;
                rbuf->buffer = tmpalloc;
                if (rbuf->write_pos < rbuf->read_pos)
                {
                        unsigned int delta = size - rbuf->size;
                        memmove(rbuf->buffer + rbuf->read_pos + delta,
                                rbuf->buffer + rbuf->read_pos,
                                rbuf->size - rbuf->read_pos);
                        rbuf->read_pos += delta;
                }
                rbuf->size = size;
        }
        return 0;
}
void ring_clear(ringbuffer *rbuf)
{
        rbuf->read_pos = 0;     
        rbuf->write_pos = 0;
}
 
 
 
void ring_destroy(ringbuffer *rbuf)
{
        free(rbuf->buffer);
}
 
 
int ring_write(ringbuffer *rbuf, uint8_t *data, int count)
{
        if (count <=0 ) return 0;
        int pos  = rbuf->write_pos;
        int rest = rbuf->size - pos;
        int free = ring_free(rbuf);
 
        if ( free < count ){
                if (DEBUG) {
                        LOG(VB_GENERAL, LOG_ERR,
                            QString("ringbuffer overflow %1<%2 %3")
                            .arg(free).arg(count).arg(rbuf->size));
                }
                return FULL_BUFFER;
        }
        
        if (count >= rest){
                memcpy (rbuf->buffer+pos, data, rest);
                if (count - rest)
                        memcpy (rbuf->buffer, data+rest, count - rest);
                rbuf->write_pos = count - rest;
        } else {
                memcpy (rbuf->buffer+pos, data, count);
                rbuf->write_pos += count;
        }
 
        if (DEBUG>1)
                LOG(VB_GENERAL, LOG_ERR, QString("Buffer empty %1%%")
                    .arg(ring_free(rbuf)*100.0/rbuf->size, 0,'f',2,QChar('0')));
        return count;
}
 
int ring_peek(ringbuffer *rbuf, uint8_t *data, unsigned int count, uint32_t off)
{
        if (off+count > rbuf->size || off+count >ring_avail(rbuf))
                return -1;
        unsigned int pos  = (rbuf->read_pos+off)%rbuf->size;
        unsigned int rest = rbuf->size - pos ;
        unsigned int avail = ring_avail(rbuf);
        
        if ( avail < count ){
#if 0
                if (DEBUG)
                        LOG(VB_GENERAL, LOG_ERR,
                            QString("ringbuffer peek underflow %1<%2 %3 %4")
                            .arg(avail).arg(count).arg(pos).arg(rbuf->write_pos));
#endif
                return EMPTY_BUFFER;
        }
 
        if ( count < rest ){
                memcpy(data, rbuf->buffer+pos, count);
        } else {
                memcpy(data, rbuf->buffer+pos, rest);
                if ( count - rest)
                        memcpy(data+rest, rbuf->buffer, count - rest);
        }
 
        return count;
}
 
int ring_peek(ringbuffer *rbuf, peek_poke_vec& data, unsigned int count, uint32_t off)
{
    return ring_peek(rbuf, data.data(), count, off);
}
 
int ring_peek(ringbuffer *rbuf, peek_poke_vec& data, uint32_t off)
{
    return ring_peek(rbuf, data.data(), data.size(), off);
}
 
int ring_poke(ringbuffer *rbuf, uint8_t *data, unsigned int count, uint32_t off)
{
        if (off+count > rbuf->size || off+count >ring_avail(rbuf))
                return -1;
        unsigned int pos  = (rbuf->read_pos+off)%rbuf->size;
        unsigned int rest = rbuf->size - pos ;
        unsigned int avail = ring_avail(rbuf);
        
        if ( avail < count ){
#if 0
                if (DEBUG)
                        LOG(VB_GENERAL, LOG_ERR,
                            QString("ringbuffer peek underflow %1<%2 %3 %4")
                            .arg(avail).arg(count).arg(pos).arg(rbuf->write_pos));
#endif
                return EMPTY_BUFFER;
        }
 
        if ( count < rest ){
                memcpy(rbuf->buffer+pos, data, count);
        } else {
                memcpy(rbuf->buffer+pos, data, rest);
                if ( count - rest)
                        memcpy(rbuf->buffer, data+rest, count - rest);
        }
 
        return count;
}
 
int ring_poke(ringbuffer *rbuf, peek_poke_vec& data, unsigned int count, uint32_t off)
{
    return ring_poke(rbuf, data.data(), count, off);
}
 
int ring_poke(ringbuffer *rbuf, peek_poke_vec& data, uint32_t off)
{
    return ring_poke(rbuf, data.data(), data.size(), off);
}
 
int ring_read(ringbuffer *rbuf, uint8_t *data, int count)
{
        if (count <=0 ) return 0;
        int pos  = rbuf->read_pos;
        int rest = rbuf->size - pos;
        int avail = ring_avail(rbuf);
        
        if ( avail < count ){
#if 0
                if (DEBUG)
                        LOG(VB_GENERAL, LOG_ERR,
                            QString("ringbuffer underflow %1<%2 %3 \n")
                            .arg(avail).arg(count).arg(rbuf->size));
#endif
                return EMPTY_BUFFER;
        }
 
        if ( count < rest ){
                memcpy(data, rbuf->buffer+pos, count);
                rbuf->read_pos += count;
        } else {
                memcpy(data, rbuf->buffer+pos, rest);
                if ( count - rest)
                        memcpy(data+rest, rbuf->buffer, count - rest);
                rbuf->read_pos = count - rest;
        }
 
        if (DEBUG>1)
                LOG(VB_GENERAL, LOG_ERR, QString("Buffer empty %1%%")
                    .arg(ring_free(rbuf)*100.0/rbuf->size, 0,'f',2,QChar('0')));
        return count;
}
 
int ring_skip(ringbuffer *rbuf, int count)
{
        if (count <=0 ) return -1;
        int pos  = rbuf->read_pos;
        int rest = rbuf->size - pos;
        int avail = ring_avail(rbuf);
 
        if ( avail < count ){
#if 0
                LOG(VB_GENERAL, LOG_ERR,
                    QString("ringbuffer skip underflow %1<%2 %3 %4\n")
                    .arg(avail).arg(count).arg(pos).arg(rbuf->write_pos));
#endif
                return EMPTY_BUFFER;
        }
        if ( count < rest ){
                rbuf->read_pos += count;
        } else {
                rbuf->read_pos = count - rest;
        }
 
        if (DEBUG>1)
            LOG(VB_GENERAL, LOG_ERR, QString("Buffer empty %1%%")
                .arg(ring_free(rbuf)*100.0/rbuf->size, 0,'f',2,QChar('0')));
        return count;
}
 
 
 
int ring_write_file(ringbuffer *rbuf, int fd, int count)
{
        int rr = 0;
 
        if (count <=0 ) return 0;
        int pos  = rbuf->write_pos;
        int rest = rbuf->size - pos;
        int free = ring_free(rbuf);
 
        if ( free < count ){
                if (DEBUG) {
                        LOG(VB_GENERAL, LOG_ERR,
                            QString("ringbuffer overflow %1<%2 %3 %4\n")
                            .arg(free).arg(count).arg(pos).arg(rbuf->read_pos));
                }
                return FULL_BUFFER;
        }
        
        if (count >= rest){
                rr = read (fd, rbuf->buffer+pos, rest);
                if (rr == rest && count - rest)
                        rr += read (fd, rbuf->buffer, count - rest);
                if (rr >=0)
                        rbuf->write_pos = (pos + rr) % rbuf->size;
        } else {
                rr = read (fd, rbuf->buffer+pos, count);
                if (rr >=0)
                        rbuf->write_pos += rr;
        }
 
        if (DEBUG>1)
            LOG(VB_GENERAL, LOG_ERR, QString("Buffer empty %.2f%%")
                .arg(ring_free(rbuf)*100.0/rbuf->size, 0,'f',2,QChar('0')));
        return rr;
}
 
 
 
int ring_read_file(ringbuffer *rbuf, int fd, int count)
{
        int rr = 0;
 
        if (count <=0 ) return -1;
        int pos  = rbuf->read_pos;
        int rest = rbuf->size - pos;
        int avail = ring_avail(rbuf);
 
        if ( avail < count ){
#if 0
                if (DEBUG)
                        LOG(VB_GENERAL, LOG_ERR,
                            QString("ringbuffer underflow %1<%2 %3 %4")
                            .arg(avail).arg(count).arg(pos).arg(rbuf->write_pos));
#endif
                return EMPTY_BUFFER;
        }
 
        if (count >= rest){
                rr = write (fd, rbuf->buffer+pos, rest);
                if (rr == rest && count - rest)
                        rr += write (fd, rbuf->buffer, count - rest);
                if (rr >=0)
                        rbuf->read_pos = (pos + rr) % rbuf->size;
        } else {
                rr = write (fd, rbuf->buffer+pos, count);
                if (rr >=0)
                        rbuf->read_pos += rr;
        }
 
 
        if (DEBUG>1)
                LOG(VB_GENERAL, LOG_ERR, QString("Buffer empty %1%%")
                    .arg(ring_free(rbuf)*100.0/rbuf->size, 0,'f',2,QChar('0')));
        return rr;
}
 
 
static void show(uint8_t *buf, int length)
{
        QString buffer;
 
        for (int i=0; i<length; i+=16){
                int j = 0;
                for (j=0; j < 8 && j+i<length; j++)
                        buffer += QString("0x%1 ").arg(buf[i+j],16,2,QChar('0'));
                for (int r=j; r<8; r++)
                        buffer += "     ";
 
                buffer += "  ";
 
                for (j=8; j < 16 && j+i<length; j++)
                        buffer += QString("0x%1 ").arg(buf[i+j],16,2,QChar('0'));
                for (int r=j; r<16; r++)
                        buffer += "     ";
 
                for (j=0; j < 16 && j+i<length; j++){
                        switch(buf[i+j]){
                        case '0'...'Z':
                        case 'a'...'z':
                                buffer += QString(QChar(buf[i+j]));
                                break;
                        default:
                                buffer += ".";
                        }
                }
                LOG(VB_GENERAL, LOG_INFO, buffer);
        }
}
 
void ring_show(ringbuffer *rbuf, unsigned int count, uint32_t off)
{
        if (off+count > rbuf->size || off+count >ring_avail(rbuf))
                return;
        unsigned int pos  = (rbuf->read_pos+off)%rbuf->size;
        unsigned int rest = rbuf->size - pos ;
        unsigned int avail = ring_avail(rbuf);
        
        if ( avail < count ){
#if 0
                if (DEBUG)
                        LOG(VB_GENERAL, LOG_ERR,
                            QString("ringbuffer peek underflow %1<%2 %3 %4\n")
                            .arg(avail).arg(count).arg(pos).arg(rbuf->write_pos));
#endif
                return;
        }
 
        if ( count < rest ){
                show(rbuf->buffer+pos, count);
        } else {
                show(rbuf->buffer+pos, rest);
                if ( count - rest)
                        show(rbuf->buffer, count - rest);
        }
}
 
 
int dummy_init(dummy_buffer *dbuf, int s)
{
        dbuf->size = s;
        dbuf->fill = 0;
        if (ring_init(&dbuf->time_index, DBUF_INDEX*sizeof(uint64_t)) < 0)
                return -1;
        if (ring_init(&dbuf->data_index, DBUF_INDEX*sizeof(int32_t)) < 0)
                return -1;
 
        return 0;
}
 
void dummy_destroy(dummy_buffer *dbuf)
{
        ring_destroy(&dbuf->time_index);
        ring_destroy(&dbuf->data_index);
}
 
void dummy_clear(dummy_buffer *dbuf)
{
        dbuf->fill = 0;
        ring_clear(&dbuf->time_index);
        ring_clear(&dbuf->data_index);
}
 
int dummy_add(dummy_buffer *dbuf, uint64_t time, uint32_t size)
{
        if (dummy_space(dbuf) < size) return -1;
#if 0
        LOG(VB_GENERAL, LOG_INFO, QString("add %1 ").arg(dummy_space(dbuf)));
#endif
        dbuf->fill += size;
        if (ring_write(&dbuf->time_index, (uint8_t *)&time, sizeof(uint64_t)) < 0) 
                return -2;
        if (ring_write(&dbuf->data_index, (uint8_t *)&size, sizeof(uint32_t)) < 0) 
                return -3;
#if 0
        LOG(VB_GENERAL, LOG_INFO,
            QString(" - %1 = %2").arg(size).arg(dummy_space(dbuf)));
#endif
        return size;
}
 
int dummy_delete(dummy_buffer *dbuf, uint64_t time)
{
        uint64_t rtime = 0;
        uint32_t size = 0;
        int ex=0;
        uint32_t dsize=0;
 
        while (ex == 0)
        {
                if (ring_peek(&dbuf->time_index,(uint8_t *) &rtime, 
                              sizeof(uint64_t), 0)<0){
                        if (dsize) break;
                        return -1;
                }
                if (ptscmp(rtime,time) < 0){
                        ring_read(&dbuf->time_index,(uint8_t *) &rtime, 
                                  sizeof(uint64_t));
                        ring_read(&dbuf->data_index,(uint8_t *) &size, 
                                  sizeof(uint32_t));
                        dsize += size;
                } else {
                        ex = 1;
                }
        }
#if 0
        LOG(VB_GENERAL, LOG_INFO, QString("delete %1 ").arg(dummy_space(dbuf)));
#endif
        dbuf->fill -= dsize;
#if 0
        LOG(VB_GENERAL, LOG_INFO,
            QString(" + %1 = %2").arg(dsize).arg(dummy_space(dbuf)));
#endif
 
        return dsize;
}
 
#if 0
static void dummy_print(dummy_buffer *dbuf)
{
   uint64_t rtime = 0;
   uint32_t size = 0;
   int avail = ring_avail(&dbuf->time_index) / sizeof(uint64_t);
   for (int i = 0; i < avail; i++) {
       ring_peek(&dbuf->time_index,(uint8_t *) &rtime, 
                              sizeof(uint64_t), i * sizeof(uint64_t));
       ring_peek(&dbuf->data_index,(uint8_t *) &size, 
                              sizeof(uint32_t), i * sizeof(uint32_t));
 
       LOG(VB_GENERAL, LOG_INFO, QString("%1 : %2 %3").arg(i)
           .arg(rtime).arg(size));
   }
   LOG(VB_GENERAL, LOG_INFO, QString("Used: %d Free: %d data-free: %d")
       .arg(avail).arg(1000-avail).arg(dbuf->size - dbuf->fill));
}
#endif