libs/ardour/lv2_event_buffer.cc

   1 /*
   2     Copyright (C) 2009 Paul Davis
   3     Author: Dave 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 #define __STDC_LIMIT_MACROS 1
  21 #include <stdint.h>
  22 #include <iostream>
  23 #include "lv2ext/lv2_event.h"
  24 #include "lv2ext/lv2_event_helpers.h"
  25 #include "ardour/lv2_event_buffer.h"
  26
  27 using namespace std;
  28
  29 namespace ARDOUR {
  30
  31
  32 /** Allocate a new event buffer.
  33  * \a capacity is in bytes (not number of events).
  34  */
  35 LV2EventBuffer::LV2EventBuffer(size_t capacity)
  36         : _latest_frames(0)
  37         , _latest_subframes(0)
  38 {
  39         if (capacity > UINT32_MAX) {
  40                 cerr << "Event buffer size " << capacity << " too large, aborting." << endl;
  41                 throw std::bad_alloc();
  42         }
  43
  44         if (capacity == 0) {
  45                 cerr << "ERROR: LV2 event buffer of size 0 created." << endl;
  46                 capacity = 1024;
  47         }
  48
  49 #ifdef NO_POSIX_MEMALIGN
  50         _data = (LV2_Event_Buffer*)malloc(sizeof(LV2_Event_Buffer) + capacity);
  51         int ret = (_data != NULL) ? 0 : -1;
  52 #else
  53         int ret = posix_memalign((void**)&_data, 16, sizeof(LV2_Event_Buffer) + capacity);
  54 #endif
  55
  56         if (ret != 0) {
  57                 cerr << "Failed to allocate event buffer.  Aborting." << endl;
  58                 exit(EXIT_FAILURE);
  59         }
  60
  61         _data->event_count = 0;
  62         _data->capacity = (uint32_t)capacity;
  63         _data->size = 0;
  64         _data->data = reinterpret_cast<uint8_t*>(_data + 1);
  65
  66         reset();
  67 }
  68
  69
  70 LV2EventBuffer::~LV2EventBuffer()
  71 {
  72         free(_data);
  73 }
  74
  75
  76 /** Increment the read position by one event.
  77  *
  78  * \return true if increment was successful, or false if end of buffer reached.
  79  */
  80 bool
  81 LV2EventBuffer::increment() const
  82 {
  83         if (lv2_event_is_valid(&_iter)) {
  84                 lv2_event_increment(&_iter);
  85                 return true;
  86         } else {
  87                 return false;
  88         }
  89 }
  90
  91
  92 /** \return true iff the cursor is valid (ie get_event is safe)
  93  */
  94 bool
  95 LV2EventBuffer::is_valid() const
  96 {
  97         return lv2_event_is_valid(&_iter);
  98 }
  99
 100
 101 /** Read an event from the current position in the buffer
 102  *
 103  * \return true if read was successful, or false if end of buffer reached
 104  */
 105 bool
 106 LV2EventBuffer::get_event(uint32_t* frames,
 107                           uint32_t* subframes,
 108                           uint16_t* type,
 109                           uint16_t* size,
 110                           uint8_t** data) const
 111 {
 112         if (lv2_event_is_valid(&_iter)) {
 113                 LV2_Event* ev = lv2_event_get(&_iter, data);
 114                 *frames = ev->frames;
 115                 *subframes = ev->subframes;
 116                 *type = ev->type;
 117                 *size = ev->size;
 118                 return true;
 119         } else {
 120                 return false;
 121         }
 122 }
 123
 124
 125 /** Append an event to the buffer.
 126  *
 127  * \a timestamp must be >= the latest event in the buffer.
 128  *
 129  * \return true on success
 130  */
 131 bool
 132 LV2EventBuffer::append(uint32_t       frames,
 133                        uint32_t       subframes,
 134                        uint16_t       type,
 135                        uint16_t       size,
 136                        const uint8_t* data)
 137 {
 138 #ifndef NDEBUG
 139         if (lv2_event_is_valid(&_iter)) {
 140                 LV2_Event* last_event = lv2_event_get(&_iter, NULL);
 141                 assert(last_event->frames < frames
 142                                 || (last_event->frames == frames && last_event->subframes <= subframes));
 143         }
 144 #endif
 145
 146         /*cout << "Appending event type " << type << ", size " << size
 147                 << " @ " << frames << "." << subframes << endl;
 148         cout << "Buffer capacity " << _data->capacity << ", size " << _data->size << endl;*/
 149
 150         if (!lv2_event_write(&_iter, frames, subframes, type, size, data)) {
 151                 cerr << "ERROR: Failed to write event." << endl;
 152                 return false;
 153         } else {
 154                 _latest_frames = frames;
 155                 _latest_subframes = subframes;
 156                 return true;
 157         }
 158 }
 159
 160
 161 /** Append a buffer of events to the buffer.
 162  *
 163  * \a timestamp must be >= the latest event in the buffer.
 164  *
 165  * \return true on success
 166  */
 167 bool
 168 LV2EventBuffer::append(const LV2_Event_Buffer* /*buf*/)
 169 {
 170         uint8_t** data = NULL;
 171         bool      ret  = true;
 172
 173         LV2_Event_Iterator iter;
 174         for (lv2_event_begin(&iter, _data); lv2_event_is_valid(&iter); lv2_event_increment(&iter)) {
 175                 LV2_Event* ev = lv2_event_get(&iter, data);
 176
 177 #ifndef NDEBUG
 178                 assert((ev->frames > _latest_frames)
 179                                 || (ev->frames == _latest_frames
 180                                         && ev->subframes >= _latest_subframes));
 181 #endif
 182
 183                 if (!(ret = append(ev->frames, ev->subframes, ev->type, ev->size, *data))) {
 184                         cerr << "ERROR: Failed to write event." << endl;
 185                         break;
 186                 }
 187
 188                 _latest_frames = ev->frames;
 189                 _latest_subframes = ev->subframes;
 190         }
 191
 192         return ret;
 193 }
 194
 195
 196 } // namespace ARDOUR
 197