Files
MapLibreParticleLab/src/storage/base_request.cpp
Konstantin Käfer 3f38c7650e add retry timers
2014-09-24 16:16:29 +02:00

83 lines
2.4 KiB
C++

#include <mbgl/storage/base_request.hpp>
#include <mbgl/storage/response.hpp>
#include <mbgl/storage/request.hpp>
#include <uv.h>
#include <cassert>
namespace mbgl {
template <typename T, typename ...Args>
void invoke(const std::forward_list<std::unique_ptr<Callback>> &list, Args&& ...args) {
for (const std::unique_ptr<Callback> &callback : list) {
assert(callback);
if (callback->is<T>()) {
callback->get<T>()(::std::forward<Args>(args)...);
}
}
}
BaseRequest::BaseRequest(const std::string &path_) : thread_id(uv_thread_self()), path(path_) {
}
// A base request can only be "canceled" by destroying the object. In that case, we'll have to
// notify all cancel callbacks.
BaseRequest::~BaseRequest() {
assert(thread_id == uv_thread_self());
notify();
}
void BaseRequest::notify() {
assert(thread_id == uv_thread_self());
// The parameter exists solely so that any calls to ->remove()
// are not going to cause deallocation of this object while this call is in progress.
util::ptr<BaseRequest> retain = self;
// Swap the lists so that it's safe for callbacks to call ->cancel()
// on the request object, which would modify the list.
const std::forward_list<std::unique_ptr<Callback>> list = std::move(callbacks);
callbacks.clear();
if (response) {
invoke<CompletedCallback>(list, *response);
} else {
invoke<AbortedCallback>(list);
}
self.reset();
}
Callback *BaseRequest::add(Callback &&callback, const util::ptr<BaseRequest> &request) {
assert(thread_id == uv_thread_self());
assert(this == request.get());
if (response) {
// We already have a response. Notify right away.
if (callback.is<CompletedCallback>()) {
callback.get<CompletedCallback>()(*response);
} else {
// We already know that this request was successful. The AbortedCallback will be discarded
// here since it would never be called.
}
return nullptr;
} else {
self = request;
callbacks.push_front(std::unique_ptr<Callback>(new Callback(std::move(callback))));
return callbacks.front().get();
}
}
void BaseRequest::remove(Callback *callback) {
assert(thread_id == uv_thread_self());
callbacks.remove_if([=](const std::unique_ptr<Callback> &cb) {
return cb.get() == callback;
});
if (callbacks.empty()) {
self.reset();
}
}
}