libs/ardour/lv2_event_buffer.cc

   1 /*
   2     Copyright (C) 2009 Paul Davis
   3     Author: David Robillard
   4
   5     This program is free software; you can redistribute it and/or modify it
   6     under the terms of the GNU General Public License as published by the Free
   7     Software Foundation; either version 2 of the License, or (at your option)
   8     any later version.
   9
  10     This program is distributed in the hope that it will be useful, but WITHOUT
  11     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13     for more details.
  14
  15     You should have received a copy of the GNU General Public License along
  16     with this program; if not, write to the Free Software Foundation, Inc.,
  17     675 Mass Ave, Cambridge, MA 02139, USA.
  18 */
  19
  20 #include <stdint.h>
  21 #include <iostream>
  22 #include "lv2ext/lv2_event.h"
  23 #include "lv2ext/lv2_event_helpers.h"
  24 #include "ardour/lv2_event_buffer.h"
  25
  26 using namespace std;
  27
  28 namespace ARDOUR {
  29
  30
  31 /** Allocate a new event buffer.
  32  * \a capacity is in bytes (not number of events).
  33  */
  34 LV2EventBuffer::LV2EventBuffer(size_t capacity)
  35         : _latest_frames(0)
  36         , _latest_subframes(0)
  37 {
  38         if (capacity > UINT32_MAX) {
  39                 cerr << "Event buffer size " << capacity << " too large, aborting." << endl;
  40                 throw std::bad_alloc();
  41         }
  42
  43         if (capacity == 0) {
  44                 cerr << "ERROR: LV2 event buffer of size 0 created." << endl;
  45                 capacity = 1024;
  46         }
  47
  48 #ifdef NO_POSIX_MEMALIGN
  49         _data = (LV2_Event_Buffer*)malloc(sizeof(LV2_Event_Buffer) + capacity);
  50         int ret = (_data != NULL) ? 0 : -1;
  51 #else
  52         int ret = posix_memalign((void**)&_data, 16, sizeof(LV2_Event_Buffer) + capacity);
  53 #endif
  54
  55         if (ret != 0) {
  56                 cerr << "Failed to allocate event buffer.  Aborting." << endl;
  57                 exit(EXIT_FAILURE);
  58         }
  59
  60         _data->event_count = 0;
  61         _data->capacity = (uint32_t)capacity;
  62         _data->size = 0;
  63         _data->data = reinterpret_cast<uint8_t*>(_data + 1);
  64
  65         reset();
  66 }
  67
  68
  69 LV2EventBuffer::~LV2EventBuffer()
  70 {
  71         free(_data);
  72 }
  73
  74
  75 /** Increment the read position by one event.
  76  *
  77  * \return true if increment was successful, or false if end of buffer reached.
  78  */
  79 bool
  80 LV2EventBuffer::increment() const
  81 {
  82         if (lv2_event_is_valid(&_iter)) {
  83                 lv2_event_increment(&_iter);
  84                 return true;
  85         } else {
  86                 return false;
  87         }
  88 }
  89
  90
  91 /** \return true iff the cursor is valid (ie get_event is safe)
  92  */
  93 bool
  94 LV2EventBuffer::is_valid() const
  95 {
  96         return lv2_event_is_valid(&_iter);
  97 }
  98
  99
 100 /** Read an event from the current position in the buffer
 101  *
 102  * \return true if read was successful, or false if end of buffer reached
 103  */
 104 bool
 105 LV2EventBuffer::get_event(uint32_t* frames,
 106                           uint32_t* subframes,
 107                           uint16_t* type,
 108                           uint16_t* size,
 109                           uint8_t** data) const
 110 {
 111         if (lv2_event_is_valid(&_iter)) {
 112                 LV2_Event* ev = lv2_event_get(&_iter, data);
 113                 *frames = ev->frames;
 114                 *subframes = ev->subframes;
 115                 *type = ev->type;
 116                 *size = ev->size;
 117                 return true;
 118         } else {
 119                 return false;
 120         }
 121 }
 122
 123
 124 /** Append an event to the buffer.
 125  *
 126  * \a timestamp must be >= the latest event in the buffer.
 127  *
 128  * \return true on success
 129  */
 130 bool
 131 LV2EventBuffer::append(uint32_t       frames,
 132                        uint32_t       subframes,
 133                        uint16_t       type,
 134                        uint16_t       size,
 135                        const uint8_t* data)
 136 {
 137 #ifndef NDEBUG
 138         if (lv2_event_is_valid(&_iter)) {
 139                 LV2_Event* last_event = lv2_event_get(&_iter, NULL);
 140                 assert(last_event->frames < frames
 141                                 || (last_event->frames == frames && last_event->subframes <= subframes));
 142         }
 143 #endif
 144
 145         /*cout << "Appending event type " << type << ", size " << size
 146                 << " @ " << frames << "." << subframes << endl;
 147         cout << "Buffer capacity " << _data->capacity << ", size " << _data->size << endl;*/
 148
 149         if (!lv2_event_write(&_iter, frames, subframes, type, size, data)) {
 150                 cerr << "ERROR: Failed to write event." << endl;
 151                 return false;
 152         } else {
 153                 _latest_frames = frames;
 154                 _latest_subframes = subframes;
 155                 return true;
 156         }
 157 }
 158
 159
 160 /** Append a buffer of events to the buffer.
 161  *
 162  * \a timestamp must be >= the latest event in the buffer.
 163  *
 164  * \return true on success
 165  */
 166 bool
 167 LV2EventBuffer::append(const LV2_Event_Buffer* /*buf*/)
 168 {
 169         uint8_t** data = NULL;
 170         bool      ret  = true;
 171
 172         LV2_Event_Iterator iter;
 173         for (lv2_event_begin(&iter, _data); lv2_event_is_valid(&iter); lv2_event_increment(&iter)) {
 174                 LV2_Event* ev = lv2_event_get(&iter, data);
 175
 176 #ifndef NDEBUG
 177                 assert((ev->frames > _latest_frames)
 178                                 || (ev->frames == _latest_frames
 179                                         && ev->subframes >= _latest_subframes));
 180 #endif
 181
 182                 if (!(ret = append(ev->frames, ev->subframes, ev->type, ev->size, *data))) {
 183                         cerr << "ERROR: Failed to write event." << endl;
 184                         break;
 185                 }
 186
 187                 _latest_frames = ev->frames;
 188                 _latest_subframes = ev->subframes;
 189         }
 190
 191         return ret;
 192 }
 193
 194
 195 } // namespace ARDOUR
 196