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Revert "Use template structs instead of phantoms"

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This reverts commit 9ab07e99f5.
This commit is contained in:
John Ericson 2020-09-30 00:39:06 +00:00
parent e9fc2031f0
commit 45a0ed82f0
8 changed files with 153 additions and 148 deletions
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151
src/libstore/worker-protocol.hh
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@ -66,96 +66,95 @@ typedef enum {
class Store;
struct Source;
/* To guide overloading */
template<typename T>
struct WorkerProto {
static T read(const Store & store, Source & from);
static void write(const Store & store, Sink & out, const T & t);
};
struct Phantom {};
#define MAKE_WORKER_PROTO(T) \
template<> \
struct WorkerProto< T > { \
static T read(const Store & store, Source & from); \
static void write(const Store & store, Sink & out, const T & t); \
}
MAKE_WORKER_PROTO(std::string);
MAKE_WORKER_PROTO(StorePath);
MAKE_WORKER_PROTO(ContentAddress);
namespace worker_proto {
/* FIXME maybe move more stuff inside here */
#define MAKE_WORKER_PROTO(TEMPLATE, T) \
TEMPLATE T read(const Store & store, Source & from, Phantom< T > _); \
TEMPLATE void write(const Store & store, Sink & out, const T & str)
MAKE_WORKER_PROTO(, std::string);
MAKE_WORKER_PROTO(, StorePath);
MAKE_WORKER_PROTO(, ContentAddress);
MAKE_WORKER_PROTO(template<typename T>, std::set<T>);
MAKE_WORKER_PROTO(template<typename T>, std::optional<T>);
#define X_ template<typename K, typename V>
#define Y_ std::map<K, V>
MAKE_WORKER_PROTO(X_, Y_);
#undef X_
#undef Y_
template<typename T>
struct WorkerProto<std::set<T>> {
static std::set<T> read(const Store & store, Source & from)
{
std::set<T> resSet;
auto size = readNum<size_t>(from);
while (size--) {
resSet.insert(WorkerProto<T>::read(store, from));
}
return resSet;
std::set<T> read(const Store & store, Source & from, Phantom<std::set<T>> _)
{
std::set<T> resSet;
auto size = readNum<size_t>(from);
while (size--) {
resSet.insert(read(store, from, Phantom<T> {}));
}
return resSet;
}
static void write(const Store & store, Sink & out, const std::set<T> & resSet)
{
out << resSet.size();
for (auto & key : resSet) {
WorkerProto<T>::write(store, out, key);
}
template<typename T>
void write(const Store & store, Sink & out, const std::set<T> & resSet)
{
out << resSet.size();
for (auto & key : resSet) {
write(store, out, key);
}
};
}
template<typename K, typename V>
struct WorkerProto<std::map<K, V>> {
static std::map<K, V> read(const Store & store, Source & from)
{
std::map<K, V> resMap;
auto size = readNum<size_t>(from);
while (size--) {
auto k = WorkerProto<K>::read(store, from);
auto v = WorkerProto<V>::read(store, from);
resMap.insert_or_assign(std::move(k), std::move(v));
}
return resMap;
std::map<K, V> read(const Store & store, Source & from, Phantom<std::map<K, V>> _)
{
std::map<K, V> resMap;
auto size = readNum<size_t>(from);
while (size--) {
auto k = read(store, from, Phantom<K> {});
auto v = read(store, from, Phantom<V> {});
resMap.insert_or_assign(std::move(k), std::move(v));
}
return resMap;
}
static void write(const Store & store, Sink & out, const std::map<K, V> & resMap)
{
out << resMap.size();
for (auto & i : resMap) {
WorkerProto<K>::write(store, out, i.first);
WorkerProto<V>::write(store, out, i.second);
}
template<typename K, typename V>
void write(const Store & store, Sink & out, const std::map<K, V> & resMap)
{
out << resMap.size();
for (auto & i : resMap) {
write(store, out, i.first);
write(store, out, i.second);
}
};
}
template<typename T>
struct WorkerProto<std::optional<T>> {
static std::optional<T> read(const Store & store, Source & from)
{
auto tag = readNum<uint8_t>(from);
switch (tag) {
case 0:
return std::nullopt;
case 1:
return WorkerProto<T>::read(store, from);
default:
throw Error("got an invalid tag bit for std::optional: %#04x", (size_t)tag);
}
std::optional<T> read(const Store & store, Source & from, Phantom<std::optional<T>> _)
{
auto tag = readNum<uint8_t>(from);
switch (tag) {
case 0:
return std::nullopt;
case 1:
return read(store, from, Phantom<T> {});
default:
throw Error("got an invalid tag bit for std::optional: %#04x", (size_t)tag);
}
}
static void write(const Store & store, Sink & out, const std::optional<T> & optVal)
{
out << (uint64_t) (optVal ? 1 : 0);
if (optVal)
WorkerProto<T>::write(store, out, *optVal);
}
};
template<typename T>
void write(const Store & store, Sink & out, const std::optional<T> & optVal)
{
out << (uint64_t) (optVal ? 1 : 0);
if (optVal)
nix::worker_proto::write(store, out, *optVal);
}
/* Specialization which uses and empty string for the empty case, taking
advantage of the fact these types always serialize to non-empty strings.
@ -163,7 +162,9 @@ struct WorkerProto<std::optional<T>> {
std::optional<T>, where <= is the compatability partial order, T is one of
the types below.
*/
MAKE_WORKER_PROTO(std::optional<StorePath>);
MAKE_WORKER_PROTO(std::optional<ContentAddress>);
MAKE_WORKER_PROTO(, std::optional<StorePath>);
MAKE_WORKER_PROTO(, std::optional<ContentAddress>);
}
}