void *
ringbuf_memcpy_from(void *dst, ringbuf_t src, size_t count, bool destroy)
{
size_t bytes_used = ringbuf_bytes_used(src);
if (count > bytes_used)
return 0;
uint8_t *u8dst = dst;
const uint8_t *bufend = ringbuf_end(src);
uint8_t *tail = src->tail;
size_t nwritten = 0;
while (nwritten != count) {
assert(bufend > src->tail);
size_t n = MIN(bufend - src->tail, count - nwritten);
memcpy(u8dst + nwritten, src->tail, n);
src->tail += n;
nwritten += n;
/* wrap ? */
if (src->tail == bufend)
src->tail = src->buf;
}
if (!destroy)
{
src->tail = tail;
assert(ringbuf_bytes_used(src) == bytes_used);
}
else
{
assert(count + ringbuf_bytes_used(src) == bytes_used);
}
return src->tail;
}
void* ringbuf_memcpy_from(void* dst, ringbuf_t src, size_t count)
{
size_t bytes_used = ringbuf_bytes_used(src);
if (count > bytes_used) {
return NULL;
}
const uint8_t* u8dst = dst;
const uint8_t* bufend = ringbuf_end(src);
size_t nwritten = 0;
while (nwritten != count) {
lwIP_ASSERT(bufend > src->tail);
size_t n = LWIP_MIN(bufend - src->tail, count - nwritten);
memcpy((uint8_t*)u8dst + nwritten, src->tail, n);
src->tail += n;
nwritten += n;
if (src->tail == bufend) {
src->tail = src->buf;
}
}
lwIP_ASSERT(count + ringbuf_bytes_used(src) == bytes_used);
return src->tail;
}
void *
ringbuf_copy(ringbuf_t dst, ringbuf_t src, size_t count)
{
size_t src_bytes_used = ringbuf_bytes_used(src);
if (count > src_bytes_used)
return 0;
int overflow = count > ringbuf_bytes_free(dst);
const uint8_t *src_bufend = ringbuf_end(src);
const uint8_t *dst_bufend = ringbuf_end(dst);
size_t ncopied = 0;
while (ncopied != count) {
assert(src_bufend > src->tail);
size_t nsrc = MIN(src_bufend - src->tail, count - ncopied);
assert(dst_bufend > dst->head);
size_t n = MIN(dst_bufend - dst->head, nsrc);
memcpy(dst->head, src->tail, n);
src->tail += n;
dst->head += n;
ncopied += n;
/* wrap ? */
if (src->tail == src_bufend)
src->tail = src->buf;
if (dst->head == dst_bufend)
dst->head = dst->buf;
}
assert(count + ringbuf_bytes_used(src) == src_bytes_used);
if (overflow) {
dst->tail = ringbuf_nextp(dst, dst->head);
assert(ringbuf_is_full(dst));
}
return dst->head;
}
static int acd_read(const char *path, char *buf, size_t size, off_t offset,
struct fuse_file_info *fi)
{
size_t len;
file_ctx * ctx = (file_ctx *) fi->fh;
pthread_mutex_lock(&ctx->readmutex); //used for async reads - prevents two reads at same time
//check if read is backwards.
size_t bufoffset = (ctx->offset-ringbuf_bytes_used(ctx->rb)); //file offset of buffer
//if buffer is ahead of read || read is ahead of buffer
if( offset != bufoffset){ //non continuouse read
ctx->abort_curl=1;//stop curl callbacks
ringbuf_reset(ctx->rb); //empty current buffer
pthread_mutex_lock(&ctx->writemutex); //lock the write thread
fprintf(stderr,"READ Reset: http offset: %u, buffered: %u, read offset: %u\n", ctx->offset, ringbuf_bytes_used(ctx->rb), offset);
ctx->offset=offset; //set new offset for http reads
ringbuf_reset(ctx->rb); //empty current buffer
ctx->abort_curl=0; //allow callbacks
pthread_mutex_unlock(&ctx->writemutex);
}
fprintf(stderr, "READ: %s, size:%u, off:%u\n", path, size, offset);
size = MIN(size,ctx->filesize-offset); //dont underflow buffer
while( ringbuf_bytes_used(ctx->rb) < size){
//fprintf(stderr, ".");//block till we have enough data
usleep(100);
}
//copy accross data
ringbuf_memcpy_from(buf, ctx->rb, size);
pthread_mutex_unlock(&ctx->readmutex);
return size;
}
ssize_t
ringbuf_write(int fd, ringbuf_t rb, size_t count)
{
size_t bytes_used = ringbuf_bytes_used(rb);
if (count > bytes_used)
return 0;
const uint8_t *bufend = ringbuf_end(rb);
assert(bufend > rb->head);
count = MIN(bufend - rb->tail, count);
ssize_t n = write(fd, rb->tail, count);
if (n > 0) {
assert(rb->tail + n <= bufend);
rb->tail += n;
/* wrap? */
if (rb->tail == bufend)
rb->tail = rb->buf;
assert(n + ringbuf_bytes_used(rb) == bytes_used);
}
return n;
}
size_t ringbuf_findchr(const struct ringbuf_t *rb, int c, size_t offset)
{
const uint8_t *bufend = ringbuf_end(rb);
size_t bytes_used = ringbuf_bytes_used(rb);
if (offset >= bytes_used)
return bytes_used;
const uint8_t *start = rb ->buf + (((rb->tail - rb->buf) + offset) % ringbuf_buffer_size(rb));
lwIP_ASSERT0(bufend > start);
size_t n = LWIP_MIN(bufend - start, bytes_used - offset);
const uint8_t *found = (const uint8_t *)memchr(start, c, n);
if (found)
return offset + (found - start);
else
return ringbuf_findchr(rb, c, offset + n);
}
void
echo_cb(EV_P_ ev_io *w_, int revents)
{
log(LOG_DEBUG, "echo_cb called");
echo_io *w = (echo_io *) w_;
msg_buf *buf = &w->buf;
if (revents & EV_WRITE) {
log(LOG_DEBUG, "echo_cb write event");
bool buf_is_full = ringbuf_is_full(buf->rb);
while (buf->msg_len) {
ssize_t n = ringbuf_write(w->io.fd,
buf->rb,
buf->msg_len);
if (n == -1) {
if ((errno == EAGAIN) ||
(errno == EWOULDBLOCK) ||
(errno == EINTR))
break;
else {
log(LOG_ERR, "Write on descriptor %d failed: %m", w->io.fd);
stop_echo_watcher(EV_A_ w);
return;
}
} else {
buf->msg_len -= n;
w->timeout.last_activity = ev_now(EV_A);
log(LOG_DEBUG, "echo_cb %zd bytes written", n);
/*
* Re-enable reads if they're paused due to buffer
* pressure.
*/
if (buf_is_full && !w->half_closed) {
log(LOG_DEBUG, "echo_cb re-starting reads.");
reset_echo_watcher(EV_A_ &w->io, EV_READ | EV_WRITE);
buf_is_full = false;
}
}
}
if (buf->msg_len == 0) {
size_t eol = ringbuf_findchr(buf->rb,
MSG_DELIMITER,
buf->search_offset);
if (eol < ringbuf_bytes_used(buf->rb)) {
buf->search_offset = 0;
buf->msg_len = eol + 1;
} else {
if (w->half_closed)
stop_echo_watcher(EV_A_ w);
else {
buf->search_offset = eol;
reset_echo_watcher(EV_A_ &w->io, EV_READ);
}
}
}
}
if (revents & EV_READ) {
log(LOG_DEBUG, "echo_cb read event");
size_t nread = 0;
while (ringbuf_bytes_free(buf->rb)) {
ssize_t n = ringbuf_read(w->io.fd,
buf->rb,
ringbuf_bytes_free(buf->rb));
if (n == 0) {
/* EOF: drain remaining writes or close connection */
log(LOG_DEBUG, "echo_cb EOF received");
w->timeout.last_activity = ev_now(EV_A);
if (buf->msg_len) {
w->half_closed = true;
reset_echo_watcher(EV_A_ &w->io, EV_WRITE);
} else
stop_echo_watcher(EV_A_ w);
return;
}
else if (n == -1) {
if ((errno == EAGAIN) ||
(errno == EWOULDBLOCK) ||
(errno == EINTR)) {
/* Nothing more to read for now. */
return;
} else {
log(LOG_ERR, "Read on descriptor %d failed: %m", w->io.fd);
stop_echo_watcher(EV_A_ w);
return;
}
} else {
nread += n;
w->timeout.last_activity = ev_now(EV_A);
log(LOG_DEBUG, "echo_cb %zd bytes read", n);
/*
* If there's no pending message to send, look for a
* new one. If found, enable writes.
*/
if (buf->msg_len == 0) {
size_t eol = ringbuf_findchr(buf->rb,
MSG_DELIMITER,
buf->search_offset);
if (eol < ringbuf_bytes_used(buf->rb)) {
buf->search_offset = 0;
buf->msg_len = eol + 1;
reset_echo_watcher(EV_A_ &w->io, EV_WRITE | EV_READ);
} else
buf->search_offset = eol;
}
}
}
/*
* If we get here, the buffer is full. If there's a pending
* message waiting to be written, disable reads until the
* writes free up space. If there's no pending message, we've
* overflowed.
*/
if (buf->msg_len) {
log(LOG_DEBUG,
"echo_cb buffer full, disabling reads on fd %d.",
w->io.fd);
reset_echo_watcher(EV_A_ &w->io, EV_WRITE);
} else {
log(LOG_WARNING, "Read overflow on descriptor %d.", w->io.fd);
stop_echo_watcher(EV_A_ w);
}
}
}
