int EFSSyncMetaFileAvailable(EFSSyncRef const sync, strarg_t const URI, strarg_t const target) {
if(!sync) return 0;
if(!URI) return UV_EINVAL;
if(!target) return UV_EINVAL;
str_t *URICopy = strdup(URI);
str_t *targetCopy = strdup(target);
if(!URICopy || !targetCopy) {
FREE(&URICopy);
FREE(&targetCopy);
return UV_ENOMEM;
}
async_mutex_lock(sync->mutex);
while(BATCH_MAX == sync->cur->metaFileURICount) {
rc = async_cond_wait(sync->cond, sync->mutex);
// TODO
}
sync->cur->metaFileURIs[sync->cur->metaFileURICount] = URICopy;
sync->cur->metaFileTargets[sync->cur->metaFileURICount] = targetCopy;
sync->cur->metaFileURICount++;
async_cond_broadcast(sync->cond);
async_mutex_unlock(sync->mutex);
return 0;
}
static void reader(SLNPullRef const pull) {
HTTPConnectionRef conn = NULL;
int rc;
for(;;) {
if(pull->stop) goto stop;
str_t URI[URI_MAX];
async_mutex_lock(pull->connlock);
rc = HTTPConnectionReadBodyLine(pull->conn, URI, sizeof(URI));
if(rc < 0) {
for(;;) {
if(pull->stop) break;
if(reconnect(pull) >= 0) break;
if(pull->stop) break;
async_sleep(1000 * 5);
}
async_mutex_unlock(pull->connlock);
continue;
}
if('#' == URI[0]) { // Comment line.
async_mutex_unlock(pull->connlock);
continue;
}
async_mutex_lock(pull->mutex);
while(pull->count + 1 > QUEUE_SIZE) {
async_cond_wait(pull->cond, pull->mutex);
if(pull->stop) {
async_mutex_unlock(pull->mutex);
async_mutex_unlock(pull->connlock);
goto stop;
}
}
size_t pos = (pull->cur + pull->count) % QUEUE_SIZE;
pull->count += 1;
async_mutex_unlock(pull->mutex);
async_mutex_unlock(pull->connlock);
for(;;) {
if(import(pull, URI, pos, &conn) >= 0) break;
if(pull->stop) goto stop;
async_sleep(1000 * 5);
}
}
stop:
HTTPConnectionFree(&conn);
async_mutex_lock(pull->mutex);
assertf(pull->stop, "Reader ended early");
assert(pull->tasks > 0);
pull->tasks--;
async_cond_broadcast(pull->cond);
async_mutex_unlock(pull->mutex);
}
static void db_thread(EFSSyncRef const sync) {
int rc;
struct queues *cur;
for(;;) {
if(sync->stop) break;
async_mutex_lock(sync->mutex);
// First we wait for anything to enter the queue.
// Then we wait an additional LATENCY_MAX for
// the queue to fill completely before processing.
while(empty(sync)) {
rc = async_cond_wait(sync->cond, sync->mutex);
if(UV_ECANCELED == rc) {
async_mutex_unlock(sync->mutex);
return; // TODO
}
}
uint64_t const future = uv_now(loop) + LATENCY_MAX;
while(!filled(sync)) {
rc = async_cond_timedwait(sync->cond, sync->mutex, future);
if(UV_ETIMEDOUT == rc) break;
if(UV_ECANCELED == rc) {
async_mutex_unlock(sync->mutex);
return; // TODO
}
}
// Double buffering.
cur = sync->cur;
sync->cur = (&sync->queues[1] == sync->cur) ?
&sync->queues[0] :
&sync->queues[1];
async_mutex_unlock(sync->mutex);
for(;;) {
rc = db_work(sync, cur);
if(DB_SUCCESS == rc) break;
fprintf(stderr, "Sync database error %s\n", db_strerror(rc));
async_sleep(1000 * 5);
}
}
// TODO: Thread joining
}
int EFSSyncFileAvailable(EFSSyncRef const sync, strarg_t const URI) {
if(!sync) return 0;
if(!URI) return UV_EINVAL;
str_t *URICopy = strdup(URI);
if(!URICopy) return UV_ENOMEM;
async_mutex_lock(sync->mutex);
while(BATCH_MAX == sync->cur->fileURICount) {
rc = async_cond_wait(sync->cond, sync->mutex);
// TODO
}
sync->cur->fileURIs[sync->cur->fileURICount++] = URICopy;
async_cond_broadcast(sync->cond);
async_mutex_unlock(sync->mutex);
return 0;
}
void SLNPullStop(SLNPullRef const pull) {
if(!pull) return;
if(pull->stop) return;
async_mutex_lock(pull->mutex);
pull->stop = true;
async_cond_broadcast(pull->cond);
while(pull->tasks > 0) {
async_cond_wait(pull->cond, pull->mutex);
}
async_mutex_unlock(pull->mutex);
HTTPConnectionFree(&pull->conn);
for(size_t i = 0; i < QUEUE_SIZE; ++i) {
SLNSubmissionFree(&pull->queue[i]);
pull->filled[i] = false;
}
pull->cur = 0;
pull->count = 0;
}
static void gen_preview(BlogRef const blog, SLNSessionRef const session, strarg_t const URI, strarg_t const path) {
// It's okay to accidentally regenerate a preview
// It's okay to send an error if another thread tried to gen and failed
// We want to minimize false positives and false negatives
// In particular, if a million connections request a new file at once,
// we want to avoid starting gen for each connection before any of them
// have finished
// Capping the total number of concurrent gens to PENDING_MAX is not
// a bad side effect
bool beat_us_to_it = false;
size_t slot = SIZE_MAX;
async_mutex_lock(blog->pending_mutex);
for(;; async_cond_wait(blog->pending_cond, blog->pending_mutex)) {
if(gen_pending(blog, path)) { beat_us_to_it = true; continue; }
if(beat_us_to_it) break;
if(gen_available(blog, path, &slot)) break;
}
async_mutex_unlock(blog->pending_mutex);
if(beat_us_to_it) return; // Note: we don't know their return status.
assert(slot < PENDING_MAX);
SLNFileInfo src[1];
int rc = SLNSessionGetFileInfo(session, URI, src);
if(rc >= 0) {
rc = -1;
rc = rc >= 0 ? rc : BlogConvert(blog, session, path, NULL, URI, src);
rc = rc >= 0 ? rc : BlogGeneric(blog, session, path, URI, src);
SLNFileInfoCleanup(src);
}
async_mutex_lock(blog->pending_mutex);
assert(path == blog->pending[slot]);
blog->pending[slot] = NULL;
async_cond_broadcast(blog->pending_cond);
async_mutex_unlock(blog->pending_mutex);
}
static void writer(SLNPullRef const pull) {
SLNSubmissionRef queue[QUEUE_SIZE];
size_t count = 0;
size_t skipped = 0;
double time = uv_now(async_loop) / 1000.0;
for(;;) {
if(pull->stop) goto stop;
async_mutex_lock(pull->mutex);
while(0 == count || (count < QUEUE_SIZE && pull->count > 0)) {
size_t const pos = pull->cur;
while(!pull->filled[pos]) {
async_cond_wait(pull->cond, pull->mutex);
if(pull->stop) {
async_mutex_unlock(pull->mutex);
goto stop;
}
if(!count) time = uv_now(async_loop) / 1000.0;
}
assert(pull->filled[pos]);
// Skip any bubbles in the queue.
if(pull->queue[pos]) queue[count++] = pull->queue[pos];
else skipped++;
pull->queue[pos] = NULL;
pull->filled[pos] = false;
pull->cur = (pull->cur + 1) % QUEUE_SIZE;
pull->count--;
async_cond_broadcast(pull->cond);
}
async_mutex_unlock(pull->mutex);
assert(count <= QUEUE_SIZE);
for(;;) {
int rc = SLNSubmissionStoreBatch(queue, count);
if(rc >= 0) break;
alogf("Submission error: %s (%d)\n", sln_strerror(rc), rc);
async_sleep(1000 * 5);
}
for(size_t i = 0; i < count; ++i) {
SLNSubmissionFree(&queue[i]);
}
double const now = uv_now(async_loop) / 1000.0;
alogf("Pulled %f files per second\n", count / (now - time));
time = now;
count = 0;
skipped = 0;
}
stop:
for(size_t i = 0; i < count; ++i) {
SLNSubmissionFree(&queue[i]);
}
assert_zeroed(queue, count);
async_mutex_lock(pull->mutex);
assertf(pull->stop, "Writer ended early");
assert(pull->tasks > 0);
pull->tasks--;
async_cond_broadcast(pull->cond);
async_mutex_unlock(pull->mutex);
}
