623 lines
20 KiB
C++
623 lines
20 KiB
C++
/* SPDX-FileCopyrightText: 2009 Benoit Bolsee
|
|
*
|
|
* SPDX-License-Identifier: LGPL-2.1-or-later */
|
|
|
|
/** \file
|
|
* \ingroup intern_itasc
|
|
*/
|
|
|
|
#include <string.h>
|
|
#include <assert.h>
|
|
#include <math.h>
|
|
#include <stdlib.h>
|
|
#include "Cache.hpp"
|
|
|
|
namespace iTaSC {
|
|
|
|
CacheEntry::~CacheEntry()
|
|
{
|
|
for (unsigned int id=0; id < m_count; id++)
|
|
m_channelArray[id].clear();
|
|
if (m_channelArray)
|
|
free(m_channelArray);
|
|
}
|
|
|
|
CacheItem *CacheChannel::_findBlock(CacheBuffer *buffer, unsigned short timeOffset, unsigned int *retBlock)
|
|
{
|
|
// the timestamp is necessarily in this buffer
|
|
unsigned int lowBlock, highBlock, midBlock;
|
|
if (timeOffset <= buffer->lookup[0].m_timeOffset) {
|
|
// special case: the item is in the first block, search from start
|
|
*retBlock = 0;
|
|
return &buffer->m_firstItem;
|
|
}
|
|
// general case, the item is in the middle of the buffer
|
|
// before doing a dycotomic search, we will assume that timestamp
|
|
// are regularly spaced so that we can try to locate the block directly
|
|
highBlock = buffer->m_lastItemPositionW>>m_positionToBlockShiftW;
|
|
lowBlock = midBlock = (timeOffset*highBlock)/(buffer->m_lastTimestamp-buffer->m_firstTimestamp);
|
|
// give some space for security
|
|
if (lowBlock > 0)
|
|
lowBlock--;
|
|
if (timeOffset <= buffer->lookup[lowBlock].m_timeOffset) {
|
|
// bad guess, but we know this block is a good high block, just use it
|
|
highBlock = lowBlock;
|
|
lowBlock = 0;
|
|
} else {
|
|
// ok, good guess, now check the high block, give some space
|
|
if (midBlock < highBlock)
|
|
midBlock++;
|
|
if (timeOffset <= buffer->lookup[midBlock].m_timeOffset) {
|
|
// good guess, keep that block as the high block
|
|
highBlock = midBlock;
|
|
}
|
|
}
|
|
// the item is in a different block, do a dycotomic search
|
|
// the timestamp is alway > lowBlock and <= highBlock
|
|
while (1) {
|
|
midBlock = (lowBlock+highBlock)/2;
|
|
if (midBlock == lowBlock) {
|
|
// low block and high block are contigous, we can start search from the low block
|
|
break;
|
|
} else if (timeOffset <= buffer->lookup[midBlock].m_timeOffset) {
|
|
highBlock = midBlock;
|
|
} else {
|
|
lowBlock = midBlock;
|
|
}
|
|
}
|
|
assert (lowBlock != highBlock);
|
|
*retBlock = highBlock;
|
|
return CACHE_BLOCK_ITEM_ADDR(this,buffer,lowBlock);
|
|
}
|
|
|
|
void CacheChannel::clear()
|
|
{
|
|
CacheBuffer *buffer, *next;
|
|
for (buffer=m_firstBuffer; buffer != 0; buffer = next) {
|
|
next = buffer->m_next;
|
|
free(buffer);
|
|
}
|
|
m_firstBuffer = NULL;
|
|
m_lastBuffer = NULL;
|
|
if (initItem) {
|
|
free(initItem);
|
|
initItem = NULL;
|
|
}
|
|
}
|
|
|
|
CacheBuffer* CacheChannel::allocBuffer()
|
|
{
|
|
CacheBuffer* buffer;
|
|
if (!m_busy)
|
|
return NULL;
|
|
buffer = (CacheBuffer*)malloc(CACHE_BUFFER_HEADER_SIZE+(m_bufferSizeW<<2));
|
|
if (buffer) {
|
|
memset(buffer, 0, CACHE_BUFFER_HEADER_SIZE);
|
|
}
|
|
return buffer;
|
|
}
|
|
|
|
CacheItem* CacheChannel::findItemOrLater(unsigned int timestamp, CacheBuffer **rBuffer)
|
|
{
|
|
CacheBuffer* buffer;
|
|
CacheItem *item, *limit;
|
|
if (!m_busy)
|
|
return NULL;
|
|
if (timestamp == 0 && initItem) {
|
|
*rBuffer = NULL;
|
|
return initItem;
|
|
}
|
|
for (buffer=m_firstBuffer; buffer; buffer = buffer->m_next) {
|
|
if (buffer->m_firstFreePositionW == 0)
|
|
// buffer is empty, this must be the last and we didn't find the timestamp
|
|
return NULL;
|
|
if (timestamp < buffer->m_firstTimestamp) {
|
|
*rBuffer = buffer;
|
|
return &buffer->m_firstItem;
|
|
}
|
|
if (timestamp <= buffer->m_lastTimestamp) {
|
|
// the timestamp is necessarily in this buffer
|
|
unsigned short timeOffset = (unsigned short)(timestamp-buffer->m_firstTimestamp);
|
|
unsigned int highBlock;
|
|
item = _findBlock(buffer, timeOffset, &highBlock);
|
|
// now we do a linear search until we find a timestamp that is equal or higher
|
|
// we should normally always find an item but let's put a limit just in case
|
|
limit = CACHE_BLOCK_ITEM_ADDR(this,buffer,highBlock);
|
|
while (item<=limit && item->m_timeOffset < timeOffset )
|
|
item = CACHE_NEXT_ITEM(item);
|
|
assert(item<=limit);
|
|
*rBuffer = buffer;
|
|
return item;
|
|
}
|
|
// search in next buffer
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
CacheItem* CacheChannel::findItemEarlier(unsigned int timestamp, CacheBuffer **rBuffer)
|
|
{
|
|
CacheBuffer *buffer, *prevBuffer;
|
|
CacheItem *item, *limit, *prevItem;
|
|
if (!m_busy)
|
|
return NULL;
|
|
if (timestamp == 0)
|
|
return NULL;
|
|
for (prevBuffer=NULL, buffer=m_firstBuffer; buffer; prevBuffer = buffer, buffer = buffer->m_next) {
|
|
if (buffer->m_firstFreePositionW == 0)
|
|
// buffer is empty, this must be the last and we didn't find the timestamp
|
|
return NULL;
|
|
if (timestamp <= buffer->m_firstTimestamp) {
|
|
if (prevBuffer == NULL) {
|
|
// no item before, except the initial item
|
|
*rBuffer = NULL;
|
|
return initItem;
|
|
}
|
|
// the item is necessarily the last one of previous buffer
|
|
*rBuffer = prevBuffer;
|
|
return CACHE_ITEM_ADDR(prevBuffer,prevBuffer->m_lastItemPositionW);
|
|
}
|
|
if (timestamp <= buffer->m_lastTimestamp) {
|
|
// the timestamp is necessarily in this buffer
|
|
unsigned short timeOffset = (unsigned short)(timestamp-buffer->m_firstTimestamp);
|
|
unsigned int highBlock;
|
|
item = _findBlock(buffer, timeOffset, &highBlock);
|
|
// now we do a linear search until we find a timestamp that is equal or higher
|
|
// we should normally always find an item but let's put a limit just in case
|
|
limit = CACHE_BLOCK_ITEM_ADDR(this,buffer,highBlock);
|
|
prevItem = NULL;
|
|
while (item<=limit && item->m_timeOffset < timeOffset) {
|
|
prevItem = item;
|
|
item = CACHE_NEXT_ITEM(item);
|
|
}
|
|
assert(item<=limit && prevItem!=NULL);
|
|
*rBuffer = buffer;
|
|
return prevItem;
|
|
}
|
|
// search in next buffer
|
|
}
|
|
// pass all buffer, the last item is the last item of the last buffer
|
|
if (prevBuffer == NULL) {
|
|
// no item before, except the initial item
|
|
*rBuffer = NULL;
|
|
return initItem;
|
|
}
|
|
// the item is necessarily the last one of previous buffer
|
|
*rBuffer = prevBuffer;
|
|
return CACHE_ITEM_ADDR(prevBuffer,prevBuffer->m_lastItemPositionW);
|
|
}
|
|
|
|
|
|
Cache::Cache()
|
|
{
|
|
}
|
|
|
|
Cache::~Cache()
|
|
{
|
|
CacheMap::iterator it;
|
|
for (it=m_cache.begin(); it!=m_cache.end(); it=m_cache.begin()) {
|
|
deleteDevice(it->first);
|
|
}
|
|
}
|
|
|
|
int Cache::addChannel(const void *device, const char *name, unsigned int maxItemSize)
|
|
{
|
|
CacheMap::iterator it = m_cache.find(device);
|
|
CacheEntry *entry;
|
|
CacheChannel *channel;
|
|
unsigned int id;
|
|
|
|
if (maxItemSize > 0x3FFF0)
|
|
return -1;
|
|
|
|
if (it == m_cache.end()) {
|
|
// device does not exist yet, create a new entry
|
|
entry = new CacheEntry();
|
|
if (entry == NULL)
|
|
return -1;
|
|
if (!m_cache.insert(CacheMap::value_type(device,entry)).second)
|
|
return -1;
|
|
} else {
|
|
entry = it->second;
|
|
}
|
|
// locate a channel with the same name and reuse
|
|
for (channel=entry->m_channelArray, id=0; id<entry->m_count; id++, channel++) {
|
|
if (channel->m_busy && !strcmp(name, channel->m_name)) {
|
|
// make this channel free again
|
|
deleteChannel(device, id);
|
|
// there can only be one channel with the same name
|
|
break;
|
|
}
|
|
}
|
|
for (channel=entry->m_channelArray, id=0; id<entry->m_count; id++, channel++) {
|
|
// locate a free channel
|
|
if (!channel->m_busy)
|
|
break;
|
|
}
|
|
if (id == entry->m_count) {
|
|
// no channel free, create new channels
|
|
int newcount = entry->m_count + CACHE_CHANNEL_EXTEND_SIZE;
|
|
channel = (CacheChannel*)realloc(entry->m_channelArray, newcount*sizeof(CacheChannel));
|
|
if (channel == NULL)
|
|
return -1;
|
|
entry->m_channelArray = channel;
|
|
memset(&entry->m_channelArray[entry->m_count], 0, CACHE_CHANNEL_EXTEND_SIZE*sizeof(CacheChannel));
|
|
entry->m_count = newcount;
|
|
channel = &entry->m_channelArray[id];
|
|
}
|
|
// compute the optimal buffer size
|
|
// The buffer size must be selected so that
|
|
// - it does not contain more than 1630 items (=1s of cache assuming 25 items per second)
|
|
// - it contains at least one item
|
|
// - it's not bigger than 256kb and preferably around 32kb
|
|
// - it a multiple of 4
|
|
unsigned int bufSize = 1630*(maxItemSize+4);
|
|
if (bufSize >= CACHE_DEFAULT_BUFFER_SIZE)
|
|
bufSize = CACHE_DEFAULT_BUFFER_SIZE;
|
|
if (bufSize < maxItemSize+16)
|
|
bufSize = maxItemSize+16;
|
|
bufSize = (bufSize + 3) & ~0x3;
|
|
// compute block size and offset bit mask
|
|
// the block size is computed so that
|
|
// - it is a power of 2
|
|
// - there is at least one item per block
|
|
// - there is no more than CACHE_LOOKUP_TABLE_SIZE blocks per buffer
|
|
unsigned int blockSize = bufSize/CACHE_LOOKUP_TABLE_SIZE;
|
|
if (blockSize < maxItemSize+12)
|
|
blockSize = maxItemSize+12;
|
|
// find the power of 2 that is immediately larger than blockSize
|
|
unsigned int m;
|
|
unsigned int pwr2Size = blockSize;
|
|
while ((m = (pwr2Size & (pwr2Size-1))) != 0)
|
|
pwr2Size = m;
|
|
blockSize = (pwr2Size < blockSize) ? pwr2Size<<1 : pwr2Size;
|
|
// convert byte size to word size because all positions and size are expressed in 32 bit words
|
|
blockSize >>= 2;
|
|
channel->m_blockSizeW = blockSize;
|
|
channel->m_bufferSizeW = bufSize>>2;
|
|
channel->m_firstBuffer = NULL;
|
|
channel->m_lastBuffer = NULL;
|
|
channel->m_busy = 1;
|
|
channel->initItem = NULL;
|
|
channel->m_maxItemSizeB = maxItemSize;
|
|
strncpy(channel->m_name, name, sizeof(channel->m_name));
|
|
channel->m_name[sizeof(channel->m_name)-1] = 0;
|
|
channel->m_positionToOffsetMaskW = (blockSize-1);
|
|
for (m=0; blockSize!=1; m++, blockSize>>=1);
|
|
channel->m_positionToBlockShiftW = m;
|
|
return (int)id;
|
|
}
|
|
|
|
int Cache::deleteChannel(const void *device, int id)
|
|
{
|
|
CacheMap::iterator it = m_cache.find(device);
|
|
CacheEntry *entry;
|
|
|
|
if (it == m_cache.end()) {
|
|
// device does not exist
|
|
return -1;
|
|
}
|
|
entry = it->second;
|
|
if (id < 0 || id >= (int)entry->m_count || !entry->m_channelArray[id].m_busy)
|
|
return -1;
|
|
entry->m_channelArray[id].clear();
|
|
entry->m_channelArray[id].m_busy = 0;
|
|
return 0;
|
|
}
|
|
|
|
int Cache::deleteDevice(const void *device)
|
|
{
|
|
CacheMap::iterator it = m_cache.find(device);
|
|
CacheEntry *entry;
|
|
|
|
if (it == m_cache.end()) {
|
|
// device does not exist
|
|
return -1;
|
|
}
|
|
entry = it->second;
|
|
delete entry;
|
|
m_cache.erase(it);
|
|
return 0;
|
|
}
|
|
|
|
void Cache::clearCacheFrom(const void *device, CacheTS timestamp)
|
|
{
|
|
CacheMap::iterator it = (device) ? m_cache.find(device) : m_cache.begin();
|
|
CacheEntry *entry;
|
|
CacheChannel *channel;
|
|
CacheBuffer *buffer, *nextBuffer, *prevBuffer;
|
|
CacheItem *item, *prevItem, *nextItem;
|
|
unsigned int positionW, block;
|
|
|
|
while (it != m_cache.end()) {
|
|
entry = it->second;
|
|
for (unsigned int ch=0; ch<entry->m_count; ch++) {
|
|
channel = &entry->m_channelArray[ch];
|
|
if (channel->m_busy) {
|
|
item = channel->findItemOrLater(timestamp, &buffer);
|
|
if (item ) {
|
|
if (!buffer) {
|
|
// this is possible if we return the special timestamp=0 item, delete all buffers
|
|
channel->clear();
|
|
} else {
|
|
// this item and all later items will be removed, clear any later buffer
|
|
while ((nextBuffer = buffer->m_next) != NULL) {
|
|
buffer->m_next = nextBuffer->m_next;
|
|
free(nextBuffer);
|
|
}
|
|
positionW = CACHE_ITEM_POSITIONW(buffer,item);
|
|
if (positionW == 0) {
|
|
// this item is the first one of the buffer, remove the buffer completely
|
|
// first find the buffer just before it
|
|
nextBuffer = channel->m_firstBuffer;
|
|
prevBuffer = NULL;
|
|
while (nextBuffer != buffer) {
|
|
prevBuffer = nextBuffer;
|
|
nextBuffer = nextBuffer->m_next;
|
|
// we must quit this loop before reaching the end of the list
|
|
assert(nextBuffer);
|
|
}
|
|
free(buffer);
|
|
buffer = prevBuffer;
|
|
if (buffer == NULL)
|
|
// this was also the first buffer
|
|
channel->m_firstBuffer = NULL;
|
|
} else {
|
|
// removing this item means finding the previous item to make it the last one
|
|
block = positionW>>channel->m_positionToBlockShiftW;
|
|
if (block == 0) {
|
|
// start from first item, we know it is not our item because positionW > 0
|
|
prevItem = &buffer->m_firstItem;
|
|
} else {
|
|
// no need to check the current block, it will point to our item or a later one
|
|
// but the previous block will be a good start for sure.
|
|
block--;
|
|
prevItem = CACHE_BLOCK_ITEM_ADDR(channel,buffer,block);
|
|
}
|
|
while ((nextItem = CACHE_NEXT_ITEM(prevItem)) < item)
|
|
prevItem = nextItem;
|
|
// we must have found our item
|
|
assert(nextItem==item);
|
|
// now set the buffer
|
|
buffer->m_lastItemPositionW = CACHE_ITEM_POSITIONW(buffer,prevItem);
|
|
buffer->m_firstFreePositionW = positionW;
|
|
buffer->m_lastTimestamp = buffer->m_firstTimestamp + prevItem->m_timeOffset;
|
|
block = buffer->m_lastItemPositionW>>channel->m_positionToBlockShiftW;
|
|
buffer->lookup[block].m_offsetW = buffer->m_lastItemPositionW&channel->m_positionToOffsetMaskW;
|
|
buffer->lookup[block].m_timeOffset = prevItem->m_timeOffset;
|
|
}
|
|
// set the channel
|
|
channel->m_lastBuffer = buffer;
|
|
if (buffer) {
|
|
channel->m_lastTimestamp = buffer->m_lastTimestamp;
|
|
channel->m_lastItemPositionW = buffer->m_lastItemPositionW;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (device)
|
|
break;
|
|
++it;
|
|
}
|
|
}
|
|
|
|
void *Cache::addCacheItem(const void *device, int id, unsigned int timestamp, void *data, unsigned int length)
|
|
{
|
|
CacheMap::iterator it = m_cache.find(device);
|
|
CacheEntry *entry;
|
|
CacheChannel *channel;
|
|
CacheBuffer *buffer, *next;
|
|
CacheItem *item;
|
|
unsigned int positionW, sizeW, block;
|
|
|
|
if (it == m_cache.end()) {
|
|
// device does not exist
|
|
return NULL;
|
|
}
|
|
entry = it->second;
|
|
if (id < 0 || id >= (int) entry->m_count || !entry->m_channelArray[id].m_busy)
|
|
return NULL;
|
|
channel = &entry->m_channelArray[id];
|
|
if (length > channel->m_maxItemSizeB)
|
|
return NULL;
|
|
if (timestamp == 0) {
|
|
// initial item, delete all buffers
|
|
channel->clear();
|
|
// and create initial item
|
|
item = NULL;
|
|
// we will allocate the memory, which is always pointer aligned => compute size
|
|
// with NULL will give same result.
|
|
sizeW = CACHE_ITEM_SIZEW(item,length);
|
|
item = (CacheItem*)calloc(sizeW, 4);
|
|
item->m_sizeW = sizeW;
|
|
channel->initItem = item;
|
|
} else {
|
|
if (!channel->m_lastBuffer) {
|
|
// no item in buffer, insert item at first position of first buffer
|
|
positionW = 0;
|
|
if ((buffer = channel->m_firstBuffer) == NULL) {
|
|
buffer = channel->allocBuffer();
|
|
channel->m_firstBuffer = buffer;
|
|
}
|
|
} else if (timestamp > channel->m_lastTimestamp) {
|
|
// this is the normal case: we are writing past lastest timestamp
|
|
buffer = channel->m_lastBuffer;
|
|
positionW = buffer->m_firstFreePositionW;
|
|
} else if (timestamp == channel->m_lastTimestamp) {
|
|
// common case, rewriting the last timestamp, just reuse the last position
|
|
buffer = channel->m_lastBuffer;
|
|
positionW = channel->m_lastItemPositionW;
|
|
} else {
|
|
// general case, write in the middle of the buffer, locate the timestamp
|
|
// (or the timestamp just after), clear this item and all future items,
|
|
// and write at that position
|
|
item = channel->findItemOrLater(timestamp, &buffer);
|
|
if (item == NULL) {
|
|
// this should not happen
|
|
return NULL;
|
|
}
|
|
// this item will become the last one of this channel, clear any later buffer
|
|
while ((next = buffer->m_next) != NULL) {
|
|
buffer->m_next = next->m_next;
|
|
free(next);
|
|
}
|
|
// no need to update the buffer, this will be done when the item is written
|
|
positionW = CACHE_ITEM_POSITIONW(buffer,item);
|
|
}
|
|
item = CACHE_ITEM_ADDR(buffer,positionW);
|
|
sizeW = CACHE_ITEM_SIZEW(item,length);
|
|
// we have positionW pointing where we can put the item
|
|
// before we do that we have to check if we can:
|
|
// - enough room
|
|
// - timestamp not too late
|
|
if ((positionW+sizeW > channel->m_bufferSizeW) ||
|
|
(positionW > 0 && timestamp >= buffer->m_firstTimestamp+0x10000)) {
|
|
// we must allocate a new buffer to store this item
|
|
// but before we must make sure that the current buffer is consistent
|
|
if (positionW != buffer->m_firstFreePositionW) {
|
|
// This means that we were trying to write in the middle of the buffer.
|
|
// We must set the buffer right with positionW being the last position
|
|
// and find the item before positionW to make it the last.
|
|
block = positionW>>channel->m_positionToBlockShiftW;
|
|
CacheItem *previousItem, *nextItem;
|
|
if (block == 0) {
|
|
// start from first item, we know it is not our item because positionW > 0
|
|
previousItem = &buffer->m_firstItem;
|
|
} else {
|
|
// no need to check the current block, it will point to our item or a later one
|
|
// but the previous block will be a good start for sure.
|
|
block--;
|
|
previousItem = CACHE_BLOCK_ITEM_ADDR(channel,buffer,block);
|
|
}
|
|
while ((nextItem = CACHE_NEXT_ITEM(previousItem)) < item)
|
|
previousItem = nextItem;
|
|
// we must have found our item
|
|
assert(nextItem==item);
|
|
// now set the buffer
|
|
buffer->m_lastItemPositionW = CACHE_ITEM_POSITIONW(buffer,previousItem);
|
|
buffer->m_firstFreePositionW = positionW;
|
|
buffer->m_lastTimestamp = buffer->m_firstTimestamp + previousItem->m_timeOffset;
|
|
block = buffer->m_lastItemPositionW>>channel->m_positionToBlockShiftW;
|
|
buffer->lookup[block].m_offsetW = buffer->m_lastItemPositionW&channel->m_positionToOffsetMaskW;
|
|
buffer->lookup[block].m_timeOffset = previousItem->m_timeOffset;
|
|
// and also the channel, just in case
|
|
channel->m_lastBuffer = buffer;
|
|
channel->m_lastTimestamp = buffer->m_lastTimestamp;
|
|
channel->m_lastItemPositionW = buffer->m_lastItemPositionW;
|
|
}
|
|
// now allocate a new buffer
|
|
buffer->m_next = channel->allocBuffer();
|
|
if (buffer->m_next == NULL)
|
|
return NULL;
|
|
buffer = buffer->m_next;
|
|
positionW = 0;
|
|
item = &buffer->m_firstItem;
|
|
sizeW = CACHE_ITEM_SIZEW(item,length);
|
|
}
|
|
// all check passed, ready to write the item
|
|
item->m_sizeW = sizeW;
|
|
if (positionW == 0) {
|
|
item->m_timeOffset = 0;
|
|
buffer->m_firstTimestamp = timestamp;
|
|
} else {
|
|
item->m_timeOffset = (unsigned short)(timestamp-buffer->m_firstTimestamp);
|
|
}
|
|
buffer->m_lastItemPositionW = positionW;
|
|
buffer->m_firstFreePositionW = positionW+sizeW;
|
|
buffer->m_lastTimestamp = timestamp;
|
|
block = positionW>>channel->m_positionToBlockShiftW;
|
|
buffer->lookup[block].m_offsetW = positionW&channel->m_positionToOffsetMaskW;
|
|
buffer->lookup[block].m_timeOffset = item->m_timeOffset;
|
|
buffer->m_lastItemPositionW = CACHE_ITEM_POSITIONW(buffer,item);
|
|
buffer->m_firstFreePositionW = buffer->m_lastItemPositionW+item->m_sizeW;
|
|
channel->m_lastBuffer = buffer;
|
|
channel->m_lastItemPositionW = positionW;
|
|
channel->m_lastTimestamp = timestamp;
|
|
}
|
|
// now copy the item
|
|
void *itemData = CACHE_ITEM_DATA_POINTER(item);
|
|
if (data)
|
|
memcpy(itemData, data, length);
|
|
return itemData;
|
|
}
|
|
|
|
const void *Cache::getPreviousCacheItem(const void *device, int id, unsigned int *timestamp)
|
|
{
|
|
CacheMap::iterator it;
|
|
CacheEntry *entry;
|
|
CacheChannel *channel;
|
|
CacheBuffer *buffer;
|
|
CacheItem *item;
|
|
|
|
if (device) {
|
|
it = m_cache.find(device);
|
|
} else {
|
|
it = m_cache.begin();
|
|
}
|
|
if (it == m_cache.end()) {
|
|
// device does not exist
|
|
return NULL;
|
|
}
|
|
entry = it->second;
|
|
if (id < 0 || id >= (int) entry->m_count || !entry->m_channelArray[id].m_busy)
|
|
return NULL;
|
|
channel = &entry->m_channelArray[id];
|
|
if ((item = channel->findItemEarlier(*timestamp,&buffer)) == NULL)
|
|
return NULL;
|
|
*timestamp = (buffer) ? buffer->m_firstTimestamp+item->m_timeOffset : 0;
|
|
return CACHE_ITEM_DATA_POINTER(item);
|
|
}
|
|
|
|
const CacheItem *Cache::getCurrentCacheItemInternal(const void *device, int id, CacheTS timestamp)
|
|
{
|
|
CacheMap::iterator it = m_cache.find(device);
|
|
CacheEntry *entry;
|
|
CacheChannel *channel;
|
|
CacheBuffer *buffer;
|
|
CacheItem *item;
|
|
|
|
if (it == m_cache.end()) {
|
|
// device does not exist
|
|
return NULL;
|
|
}
|
|
entry = it->second;
|
|
if (id < 0 || id >= (int) entry->m_count || !entry->m_channelArray[id].m_busy)
|
|
return NULL;
|
|
channel = &entry->m_channelArray[id];
|
|
if ((item = channel->findItemOrLater(timestamp,&buffer)) == NULL)
|
|
return NULL;
|
|
if (buffer && buffer->m_firstTimestamp+item->m_timeOffset != timestamp)
|
|
return NULL;
|
|
return item;
|
|
}
|
|
|
|
const void *Cache::getCurrentCacheItem(const void *device, int channel, unsigned int timestamp)
|
|
{
|
|
const CacheItem *item = getCurrentCacheItemInternal(device, channel, timestamp);
|
|
return (item) ? CACHE_ITEM_DATA_POINTER(item) : NULL;
|
|
}
|
|
|
|
double *Cache::addCacheVectorIfDifferent(const void *device, int channel, CacheTS timestamp, double *newdata, unsigned int length, double threshold)
|
|
{
|
|
const CacheItem *item = getCurrentCacheItemInternal(device, channel, timestamp);
|
|
unsigned int sizeW = CACHE_ITEM_SIZEW(item,length*sizeof(double));
|
|
if (!item || item->m_sizeW != sizeW)
|
|
return (double*)addCacheItem(device, channel, timestamp, newdata, length*sizeof(double));
|
|
double *olddata = (double*)CACHE_ITEM_DATA_POINTER(item);
|
|
if (!length)
|
|
return olddata;
|
|
double *ref = olddata;
|
|
double *v = newdata;
|
|
unsigned int i;
|
|
for (i=length; i>0; --i) {
|
|
if (fabs(*v-*ref) > threshold)
|
|
break;
|
|
*ref++ = *v++;
|
|
}
|
|
if (i)
|
|
olddata = (double*)addCacheItem(device, channel, timestamp, newdata, length*sizeof(double));
|
|
return olddata;
|
|
}
|
|
|
|
}
|