mirror of
https://github.com/privatevoid-net/nix-super.git
synced 2024-11-21 21:46:15 +02:00
Ensure that Callback is called only once
Also, make Callback movable but uncopyable.
This commit is contained in:
parent
8c4ea7a451
commit
7348653ff4
5 changed files with 36 additions and 17 deletions
|
@ -249,21 +249,23 @@ void BinaryCacheStore::queryPathInfoUncached(const Path & storePath,
|
|||
|
||||
auto narInfoFile = narInfoFileFor(storePath);
|
||||
|
||||
auto callbackPtr = std::make_shared<decltype(callback)>(std::move(callback));
|
||||
|
||||
getFile(narInfoFile,
|
||||
{[=](std::future<std::shared_ptr<std::string>> fut) {
|
||||
try {
|
||||
auto data = fut.get();
|
||||
|
||||
if (!data) return callback(nullptr);
|
||||
if (!data) return (*callbackPtr)(nullptr);
|
||||
|
||||
stats.narInfoRead++;
|
||||
|
||||
callback((std::shared_ptr<ValidPathInfo>)
|
||||
(*callbackPtr)((std::shared_ptr<ValidPathInfo>)
|
||||
std::make_shared<NarInfo>(*this, *data, narInfoFile));
|
||||
|
||||
(void) act; // force Activity into this lambda to ensure it stays alive
|
||||
} catch (...) {
|
||||
callback.rethrow();
|
||||
callbackPtr->rethrow();
|
||||
}
|
||||
}});
|
||||
}
|
||||
|
|
|
@ -77,13 +77,13 @@ struct CurlDownloader : public Downloader
|
|||
|
||||
DownloadItem(CurlDownloader & downloader,
|
||||
const DownloadRequest & request,
|
||||
Callback<DownloadResult> callback)
|
||||
Callback<DownloadResult> && callback)
|
||||
: downloader(downloader)
|
||||
, request(request)
|
||||
, act(*logger, lvlTalkative, actDownload,
|
||||
fmt(request.data ? "uploading '%s'" : "downloading '%s'", request.uri),
|
||||
{request.uri}, request.parentAct)
|
||||
, callback(callback)
|
||||
, callback(std::move(callback))
|
||||
, finalSink([this](const unsigned char * data, size_t len) {
|
||||
if (this->request.dataCallback) {
|
||||
writtenToSink += len;
|
||||
|
@ -665,7 +665,7 @@ struct CurlDownloader : public Downloader
|
|||
return;
|
||||
}
|
||||
|
||||
enqueueItem(std::make_shared<DownloadItem>(*this, request, callback));
|
||||
enqueueItem(std::make_shared<DownloadItem>(*this, request, std::move(callback)));
|
||||
}
|
||||
};
|
||||
|
||||
|
|
|
@ -137,17 +137,19 @@ protected:
|
|||
|
||||
auto request(makeRequest(path));
|
||||
|
||||
auto callbackPtr = std::make_shared<decltype(callback)>(std::move(callback));
|
||||
|
||||
getDownloader()->enqueueDownload(request,
|
||||
{[callback, this](std::future<DownloadResult> result) {
|
||||
{[callbackPtr, this](std::future<DownloadResult> result) {
|
||||
try {
|
||||
callback(result.get().data);
|
||||
(*callbackPtr)(result.get().data);
|
||||
} catch (DownloadError & e) {
|
||||
if (e.error == Downloader::NotFound || e.error == Downloader::Forbidden)
|
||||
return callback(std::shared_ptr<std::string>());
|
||||
return (*callbackPtr)(std::shared_ptr<std::string>());
|
||||
maybeDisable();
|
||||
callback.rethrow();
|
||||
callbackPtr->rethrow();
|
||||
} catch (...) {
|
||||
callback.rethrow();
|
||||
callbackPtr->rethrow();
|
||||
}
|
||||
}});
|
||||
}
|
||||
|
|
|
@ -365,8 +365,10 @@ void Store::queryPathInfo(const Path & storePath,
|
|||
|
||||
} catch (...) { return callback.rethrow(); }
|
||||
|
||||
auto callbackPtr = std::make_shared<decltype(callback)>(std::move(callback));
|
||||
|
||||
queryPathInfoUncached(storePath,
|
||||
{[this, storePath, hashPart, callback](std::future<std::shared_ptr<ValidPathInfo>> fut) {
|
||||
{[this, storePath, hashPart, callbackPtr](std::future<std::shared_ptr<ValidPathInfo>> fut) {
|
||||
|
||||
try {
|
||||
auto info = fut.get();
|
||||
|
@ -386,8 +388,8 @@ void Store::queryPathInfo(const Path & storePath,
|
|||
throw InvalidPath("path '%s' is not valid", storePath);
|
||||
}
|
||||
|
||||
callback(ref<ValidPathInfo>(info));
|
||||
} catch (...) { callback.rethrow(); }
|
||||
(*callbackPtr)(ref<ValidPathInfo>(info));
|
||||
} catch (...) { callbackPtr->rethrow(); }
|
||||
}});
|
||||
}
|
||||
|
||||
|
|
|
@ -445,21 +445,34 @@ string get(const T & map, const string & key, const string & def = "")
|
|||
type T or an exception. (We abuse std::future<T> to pass the value or
|
||||
exception.) */
|
||||
template<typename T>
|
||||
struct Callback
|
||||
class Callback
|
||||
{
|
||||
std::function<void(std::future<T>)> fun;
|
||||
std::atomic_flag done = ATOMIC_FLAG_INIT;
|
||||
|
||||
public:
|
||||
|
||||
Callback(std::function<void(std::future<T>)> fun) : fun(fun) { }
|
||||
|
||||
void operator()(T && t) const
|
||||
Callback(Callback && callback) : fun(std::move(callback.fun))
|
||||
{
|
||||
auto prev = callback.done.test_and_set();
|
||||
if (prev) done.test_and_set();
|
||||
}
|
||||
|
||||
void operator()(T && t)
|
||||
{
|
||||
auto prev = done.test_and_set();
|
||||
assert(!prev);
|
||||
std::promise<T> promise;
|
||||
promise.set_value(std::move(t));
|
||||
fun(promise.get_future());
|
||||
}
|
||||
|
||||
void rethrow(const std::exception_ptr & exc = std::current_exception()) const
|
||||
void rethrow(const std::exception_ptr & exc = std::current_exception())
|
||||
{
|
||||
auto prev = done.test_and_set();
|
||||
assert(!prev);
|
||||
std::promise<T> promise;
|
||||
promise.set_exception(exc);
|
||||
fun(promise.get_future());
|
||||
|
|
Loading…
Reference in a new issue