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#include <mbgl/storage/default_file_source_impl.hpp>
#include <mbgl/storage/request.hpp>
#include <mbgl/storage/asset_context.hpp>
#include <mbgl/storage/http_context.hpp>
#include <mbgl/storage/response.hpp>
#include <mbgl/platform/platform.hpp>
#include <mbgl/util/uv_detail.hpp>
#include <mbgl/util/chrono.hpp>
#include <mbgl/util/thread.hpp>
#include <mbgl/platform/log.hpp>
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wshadow"
#pragma GCC diagnostic ignored "-Wunknown-pragmas"
#pragma GCC diagnostic ignored "-Wunused-local-typedefs"
#include <boost/algorithm/string.hpp>
#pragma GCC diagnostic pop
#include <algorithm>
#include <cassert>
namespace algo = boost::algorithm;
namespace mbgl {
DefaultFileSource::DefaultFileSource(FileCache* cache, const std::string& root)
: thread(util::make_unique<util::Thread<Impl>>("FileSource", cache, root)) {
}
DefaultFileSource::~DefaultFileSource() {
MBGL_VERIFY_THREAD(tid);
}
Request* DefaultFileSource::request(const Resource& resource,
uv_loop_t* l,
Callback callback) {
auto req = new Request(resource, l, std::move(callback));
// This function can be called from any thread. Make sure we're executing the actual call in the
// file source loop by sending it over the queue.
thread->invoke(&Impl::add, req);
return req;
}
void DefaultFileSource::request(const Resource& resource, Callback callback) {
request(resource, nullptr, std::move(callback));
}
void DefaultFileSource::cancel(Request *req) {
req->cancel();
// This function can be called from any thread. Make sure we're executing the actual call in the
// file source loop by sending it over the queue.
thread->invoke(&Impl::cancel, req);
}
// ----- Impl -----
DefaultFileSource::Impl::Impl(uv_loop_t* loop_, FileCache* cache_, const std::string& root)
: loop(loop_),
cache(cache_),
assetRoot(root.empty() ? platform::assetRoot() : root),
assetContext(AssetContext::createContext(loop_)),
httpContext(HTTPContext::createContext(loop_)) {
}
DefaultFileRequest* DefaultFileSource::Impl::find(const Resource& resource) {
const auto it = pending.find(resource);
if (it != pending.end()) {
return &it->second;
}
return nullptr;
}
void DefaultFileSource::Impl::add(Request* req) {
const Resource& resource = req->resource;
DefaultFileRequest* request = find(resource);
if (request) {
request->observers.insert(req);
return;
}
request = &pending.emplace(resource, DefaultFileRequest(resource)).first->second;
request->observers.insert(req);
if (cache) {
startCacheRequest(resource);
} else {
startRealRequest(resource);
}
}
void DefaultFileSource::Impl::startCacheRequest(const Resource& resource) {
// Check the cache for existing data so that we can potentially
// revalidate the information without having to redownload everything.
cache->get(resource, [this, resource](std::unique_ptr<Response> response) {
DefaultFileRequest* request = find(resource);
if (!request) {
// There is no request for this URL anymore. Likely, the request was canceled
// before we got around to process the cache result.
return;
}
auto expired = [&response] {
const int64_t now = std::chrono::duration_cast<std::chrono::seconds>(
SystemClock::now().time_since_epoch()).count();
return response->expires <= now;
};
if (!response || expired()) {
// No response or stale cache. Run the real request.
startRealRequest(resource, std::move(response));
} else {
// The response is fresh. We're good to notify the caller.
notify(request, std::move(response), FileCache::Hint::No);
}
});
}
void DefaultFileSource::Impl::startRealRequest(const Resource& resource, std::shared_ptr<const Response> response) {
DefaultFileRequest* request = find(resource);
auto callback = [request, this] (std::shared_ptr<const Response> res, FileCache::Hint hint) {
notify(request, res, hint);
};
if (algo::starts_with(resource.url, "asset://")) {
request->request = assetContext->createRequest(resource, callback, loop, assetRoot);
} else {
request->request = httpContext->createRequest(resource, callback, loop, response);
}
}
void DefaultFileSource::Impl::cancel(Request* req) {
DefaultFileRequest* request = find(req->resource);
if (request) {
// If the number of dependent requests of the DefaultFileRequest drops to zero,
// cancel the request and remove it from the pending list.
request->observers.erase(req);
if (request->observers.empty()) {
if (request->request) {
request->request->cancel();
}
pending.erase(request->resource);
}
} else {
// There is no request for this URL anymore. Likely, the request already completed
// before we got around to process the cancelation request.
}
// Send a message back to the requesting thread and notify it that this request has been
// canceled and is now safe to be deleted.
req->destruct();
}
void DefaultFileSource::Impl::notify(DefaultFileRequest* request, std::shared_ptr<const Response> response, FileCache::Hint hint) {
// First, remove the request, since it might be destructed at any point now.
assert(find(request->resource) == request);
assert(response);
// Notify all observers.
for (auto req : request->observers) {
req->notify(response);
}
if (cache) {
// Store response in database
cache->put(request->resource, response, hint);
}
pending.erase(request->resource);
}
}
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