static void sendEventPacket(outputCommonState state, caerEventPacketHeader packet) {
// Calculate total size of packet, in bytes.
size_t packetSize = CAER_EVENT_PACKET_HEADER_SIZE
+ (size_t) (caerEventPacketHeaderGetEventCapacity(packet) * caerEventPacketHeaderGetEventSize(packet));
// Statistics support.
state->statistics.packetsNumber++;
state->statistics.packetsTotalSize += packetSize;
state->statistics.packetsHeaderSize += CAER_EVENT_PACKET_HEADER_SIZE;
state->statistics.packetsDataSize += (size_t) (caerEventPacketHeaderGetEventCapacity(packet)
* caerEventPacketHeaderGetEventSize(packet));
if (state->format != 0) {
packetSize = compressEventPacket(state, packet, packetSize);
}
// Statistics support (after compression).
state->statistics.dataWritten += packetSize;
// Send it out until none is left!
size_t packetIndex = 0;
while (packetSize > 0) {
// Calculate remaining space in current buffer.
size_t usableBufferSpace = state->dataBuffer->bufferSize - state->dataBuffer->bufferUsedSize;
// Let's see how much of it (or all of it!) we need.
if (packetSize < usableBufferSpace) {
usableBufferSpace = packetSize;
}
// Copy memory from packet to buffer.
memcpy(state->dataBuffer->buffer + state->dataBuffer->bufferUsedSize, ((uint8_t *) packet) + packetIndex,
usableBufferSpace);
// Update indexes.
state->dataBuffer->bufferUsedSize += usableBufferSpace;
packetIndex += usableBufferSpace;
packetSize -= usableBufferSpace;
if (state->dataBuffer->bufferUsedSize == state->dataBuffer->bufferSize) {
// Commit buffer once full.
commitOutputBuffer(state);
}
}
// Each commit operation updates the last committed buffer time.
// The above code resulted in some commits, with the time being updated,
// or in no commits at all, with the time remaining as before.
// Here we check that the time difference between now and the last actual
// commit doesn't exceed the allowed maximum interval.
struct timespec currentTime;
portable_clock_gettime_monotonic(¤tTime);
uint64_t diffNanoTime = (uint64_t) (((int64_t) (currentTime.tv_sec - state->bufferLastCommitTime.tv_sec)
* 1000000000LL) + (int64_t) (currentTime.tv_nsec - state->bufferLastCommitTime.tv_nsec));
// DiffNanoTime is the difference in nanoseconds; we want to trigger after
// the user provided interval has elapsed (also in nanoseconds).
if (diffNanoTime >= state->bufferMaxInterval) {
commitOutputBuffer(state);
}
}
int main(int argc, char *argv[]) {
// Install signal handler for global shutdown.
struct sigaction shutdownAction;
shutdownAction.sa_handler = &globalShutdownSignalHandler;
shutdownAction.sa_flags = 0;
sigemptyset(&shutdownAction.sa_mask);
sigaddset(&shutdownAction.sa_mask, SIGTERM);
sigaddset(&shutdownAction.sa_mask, SIGINT);
if (sigaction(SIGTERM, &shutdownAction, NULL) == -1) {
caerLog(CAER_LOG_CRITICAL, "ShutdownAction", "Failed to set signal handler for SIGTERM. Error: %d.", errno);
return (EXIT_FAILURE);
}
if (sigaction(SIGINT, &shutdownAction, NULL) == -1) {
caerLog(CAER_LOG_CRITICAL, "ShutdownAction", "Failed to set signal handler for SIGINT. Error: %d.", errno);
return (EXIT_FAILURE);
}
// First of all, parse the IP:Port we need to listen on.
// Those are for now also the only two parameters permitted.
// If none passed, attempt to connect to default TCP IP:Port.
const char *ipAddress = "127.0.0.1";
uint16_t portNumber = 7777;
if (argc != 1 && argc != 3) {
fprintf(stderr, "Incorrect argument number. Either pass none for default IP:Port"
"combination of 127.0.0.1:7777, or pass the IP followed by the Port.\n");
return (EXIT_FAILURE);
}
// If explicitly passed, parse arguments.
if (argc == 3) {
ipAddress = argv[1];
sscanf(argv[2], "%" SCNu16, &portNumber);
}
// Create listening socket for TCP data.
int listenTCPSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (listenTCPSocket < 0) {
fprintf(stderr, "Failed to create TCP socket.\n");
return (EXIT_FAILURE);
}
struct sockaddr_in listenTCPAddress;
memset(&listenTCPAddress, 0, sizeof(struct sockaddr_in));
listenTCPAddress.sin_family = AF_INET;
listenTCPAddress.sin_port = htons(portNumber);
inet_aton(ipAddress, &listenTCPAddress.sin_addr); // htonl() is implicit here.
if (connect(listenTCPSocket, (struct sockaddr *) &listenTCPAddress, sizeof(struct sockaddr_in)) < 0) {
fprintf(stderr, "Failed to connect to remote TCP data server.\n");
return (EXIT_FAILURE);
}
// 64K data buffer should be enough for the TCP event packets.
size_t dataBufferLength = 1024 * 64;
uint8_t *dataBuffer = malloc(dataBufferLength);
while (!atomic_load_explicit(&globalShutdown, memory_order_relaxed)) {
// Get packet header, to calculate packet size.
if (!recvUntilDone(listenTCPSocket, dataBuffer, sizeof(struct caer_event_packet_header))) {
fprintf(stderr, "Error in header recv() call: %d\n", errno);
continue;
}
// Decode successfully received data.
caerEventPacketHeader header = (caerEventPacketHeader) dataBuffer;
int16_t eventType = caerEventPacketHeaderGetEventType(header);
int16_t eventSource = caerEventPacketHeaderGetEventSource(header);
int32_t eventSize = caerEventPacketHeaderGetEventSize(header);
int32_t eventTSOffset = caerEventPacketHeaderGetEventTSOffset(header);
int32_t eventCapacity = caerEventPacketHeaderGetEventCapacity(header);
int32_t eventNumber = caerEventPacketHeaderGetEventNumber(header);
int32_t eventValid = caerEventPacketHeaderGetEventValid(header);
printf(
"type = %" PRIi16 ", source = %" PRIi16 ", size = %" PRIi32 ", tsOffset = %" PRIi32 ", capacity = %" PRIi32 ", number = %" PRIi32 ", valid = %" PRIi32 ".\n",
eventType, eventSource, eventSize, eventTSOffset, eventCapacity, eventNumber, eventValid);
// Get rest of event packet, the part with the events themselves.
if (!recvUntilDone(listenTCPSocket, dataBuffer + sizeof(struct caer_event_packet_header),
(size_t) (eventCapacity * eventSize))) {
fprintf(stderr, "Error in data recv() call: %d\n", errno);
continue;
}
if (eventValid > 0) {
void *firstEvent = caerGenericEventGetEvent(header, 0);
void *lastEvent = caerGenericEventGetEvent(header, eventValid - 1);
int32_t firstTS = caerGenericEventGetTimestamp(firstEvent, header);
int32_t lastTS = caerGenericEventGetTimestamp(lastEvent, header);
int32_t tsDifference = lastTS - firstTS;
printf("Time difference in packet: %" PRIi32 " (first = %" PRIi32 ", last = %" PRIi32 ").\n", tsDifference,
firstTS, lastTS);
}
printf("\n\n");
}
// Close connection.
close(listenTCPSocket);
free(dataBuffer);
return (EXIT_SUCCESS);
}
static inline bool caerFrameEventPNGCompress(uint8_t **outBuffer, size_t *outSize, uint16_t *inBuffer, int32_t xSize,
int32_t ySize, enum caer_frame_event_color_channels channels) {
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
png_byte **row_pointers = NULL;
// Initialize the write struct.
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (png_ptr == NULL) {
return (false);
}
// Initialize the info struct.
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
png_destroy_write_struct(&png_ptr, NULL);
return (false);
}
// Set up error handling.
if (setjmp(png_jmpbuf(png_ptr))) {
if (row_pointers != NULL) {
png_free(png_ptr, row_pointers);
}
png_destroy_write_struct(&png_ptr, &info_ptr);
return (false);
}
// Set image attributes.
png_set_IHDR(png_ptr, info_ptr, (png_uint_32) xSize, (png_uint_32) ySize, 16, caerFrameEventColorToLibPNG(channels),
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
// Handle endianness of 16-bit depth pixels correctly.
// PNG assumes big-endian, our Frame Event is always little-endian.
png_set_swap(png_ptr);
// Initialize rows of PNG.
row_pointers = png_malloc(png_ptr, (size_t) ySize * sizeof(png_byte *));
if (row_pointers == NULL) {
png_destroy_write_struct(&png_ptr, &info_ptr);
return (false);
}
for (size_t y = 0; y < (size_t) ySize; y++) {
row_pointers[y] = (png_byte *) &inBuffer[y * (size_t) xSize * channels];
}
// Set write function to buffer one.
struct mem_encode state = { .buffer = NULL, .size = 0 };
png_set_write_fn(png_ptr, &state, &caerLibPNGWriteBuffer, NULL);
// Actually write the image data.
png_set_rows(png_ptr, info_ptr, row_pointers);
png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
// Free allocated memory for rows.
png_free(png_ptr, row_pointers);
// Destroy main structs.
png_destroy_write_struct(&png_ptr, &info_ptr);
// Pass out buffer with resulting PNG image.
*outBuffer = state.buffer;
*outSize = state.size;
return (true);
}
#endif
static size_t compressEventPacket(outputCommonState state, caerEventPacketHeader packet, size_t packetSize) {
// Data compression technique 1: serialize timestamps for event types that tend to repeat them a lot.
// Currently, this means polarity events.
if ((state->format & 0x01) && caerEventPacketHeaderGetEventType(packet) == POLARITY_EVENT) {
// Search for runs of at least 3 events with the same timestamp, and convert them to a special
// sequence: leave first event unchanged, but mark its timestamp as special by setting the
// highest bit (bit 31) to one (it is forbidden for timestamps in memory to have that bit set for
// signed-integer-only language compatibility). Then, for the second event, change its timestamp
// to a 4-byte integer saying how many more events will follow afterwards with this same timestamp
// (this is used for decoding), so only their data portion will be given. Then follow with those
// event's data, back to back, with their timestamps removed.
// So let's assume there are 6 events with TS=1234. In memory this looks like this:
// E1(data,ts), E2(data,ts), E3(data,ts), E4(data,ts), E5(data,ts), E6(data,ts)
// After timestamp serialization compression step:
// E1(data,ts|0x80000000), E2(data,4), E3(data), E4(data), E5(data), E5(data)
// This change is only in the data itself, not in the packet headers, so that we can still use the
// eventCapacity and eventSize fields to calculate memory allocation when doing decompression.
// As such, to correctly interpret this data, the Format flags must be correctly set. All current
// file or network formats do specify those as mandatory in their headers, so we can rely on that.
// Also all event types where this kind of thing makes any sense do have the timestamp as their last
// data member in their struct, so we can use that information, stored in tsOffset header field,
// together with eventSize, to come up with a generic implementation applicable to all other event
// types that satisfy this condition of TS-as-last-member (so we can use that offset as event size).
// When this is enabled, it requires full iteration thorough the whole event packet, both at
// compression and at decompression time.
size_t currPacketOffset = CAER_EVENT_PACKET_HEADER_SIZE; // Start here, no change to header.
int32_t eventSize = caerEventPacketHeaderGetEventSize(packet);
int32_t eventTSOffset = caerEventPacketHeaderGetEventTSOffset(packet);
int32_t lastTS = -1;
int32_t currTS = -1;
size_t tsRun = 0;
bool doMemMove = false; // Initially don't move memory, until we actually shrink the size.
for (int32_t caerIteratorCounter = 0; caerIteratorCounter <= caerEventPacketHeaderGetEventNumber(packet);
caerIteratorCounter++) {
// Iterate until one element past the end, to flush the last run. In that particular case,
// we don't get a new element or TS, as we'd be past the end of the array.
if (caerIteratorCounter < caerEventPacketHeaderGetEventNumber(packet)) {
void *caerIteratorElement = caerGenericEventGetEvent(packet, caerIteratorCounter);
currTS = caerGenericEventGetTimestamp(caerIteratorElement, packet);
if (currTS == lastTS) {
// Increase size of run of same TS events currently being seen.
tsRun++;
continue;
}
}
// TS are different, at this point look if the last run was long enough
// and if it makes sense to compress. It does starting with 3 events.
if (tsRun >= 3) {
// First event to remains there, we set its TS highest bit.
uint8_t *firstEvent = caerGenericEventGetEvent(packet, caerIteratorCounter - (int32_t) tsRun--);
caerGenericEventSetTimestamp(firstEvent, packet,
caerGenericEventGetTimestamp(firstEvent, packet) | I32T(0x80000000));
// Now use second event's timestamp for storing how many further events.
uint8_t *secondEvent = caerGenericEventGetEvent(packet, caerIteratorCounter - (int32_t) tsRun--);
caerGenericEventSetTimestamp(secondEvent, packet, I32T(tsRun)); // Is at least 1.
// Finally move modified memory where it needs to go.
if (doMemMove) {
memmove(((uint8_t *) packet) + currPacketOffset, firstEvent, (size_t) eventSize * 2);
}
else {
doMemMove = true; // After first shrink always move memory.
}
currPacketOffset += (size_t) eventSize * 2;
// Now go through remaining events and move their data close together.
while (tsRun > 0) {
uint8_t *thirdEvent = caerGenericEventGetEvent(packet, caerIteratorCounter - (int32_t) tsRun--);
memmove(((uint8_t *) packet) + currPacketOffset, thirdEvent, (size_t) eventTSOffset);
currPacketOffset += (size_t) eventTSOffset;
}
}
else {
// Just copy data unchanged if no compression is possible.
if (doMemMove) {
uint8_t *startEvent = caerGenericEventGetEvent(packet, caerIteratorCounter - (int32_t) tsRun);
memmove(((uint8_t *) packet) + currPacketOffset, startEvent, (size_t) eventSize * tsRun);
}
currPacketOffset += (size_t) eventSize * tsRun;
}
// Reset values for next iteration.
lastTS = currTS;
tsRun = 1;
}
return (currPacketOffset);
}
#ifdef ENABLE_INOUT_PNG_COMPRESSION
// Data compression technique 2: do PNG compression on frames, Grayscale and RGB(A).
if ((state->format & 0x02) && caerEventPacketHeaderGetEventType(packet) == FRAME_EVENT) {
size_t currPacketOffset = CAER_EVENT_PACKET_HEADER_SIZE; // Start here, no change to header.
size_t frameHeaderSize = sizeof(struct caer_frame_event);
CAER_FRAME_ITERATOR_ALL_START((caerFrameEventPacket) packet)
size_t pixelSize = caerFrameEventGetPixelsSize(caerFrameIteratorElement);
// Keep frame event header intact, compress image data, move memory close together.
memmove(((uint8_t *) packet) + currPacketOffset, caerFrameIteratorElement, frameHeaderSize);
currPacketOffset += frameHeaderSize;
uint8_t *outBuffer;
size_t outSize;
if (!caerFrameEventPNGCompress(&outBuffer, &outSize,
caerFrameEventGetPixelArrayUnsafe(caerFrameIteratorElement),
caerFrameEventGetLengthX(caerFrameIteratorElement), caerFrameEventGetLengthY(caerFrameIteratorElement),
caerFrameEventGetChannelNumber(caerFrameIteratorElement))) {
// Failed to generate PNG.
// Discard this frame event.
currPacketOffset -= frameHeaderSize;
continue;
}
// Check that the image didn't actually grow.
// Add integer needed for storing PNG block length.
if ((outSize + sizeof(int32_t)) > pixelSize) {
caerLog(CAER_LOG_ERROR, state->parentModule->moduleSubSystemString, "Failed to compress frame event. "
"Image actually grew by %zu bytes to a total of %zu bytes.", (outSize - pixelSize), outSize);
free(outBuffer);
currPacketOffset -= frameHeaderSize;
continue;
}
// Store size of PNG image block as 4 byte integer.
int32_t outSizeInt = I32T(outSize);
memcpy(((uint8_t *) packet) + currPacketOffset, &outSizeInt, sizeof(int32_t));
currPacketOffset += sizeof(int32_t);
memcpy(((uint8_t *) packet) + currPacketOffset, outBuffer, outSize);
currPacketOffset += outSize;
// Free allocated PNG block memory.
free(outBuffer);
}
return (currPacketOffset);
}
#endif
return (packetSize);
}
