#include "types.h"
#include "rpc_protocol.h"
-// for structs or classes containing a MEMBERS declaration
class marshall;
class unmarshall;
-#define FORWARD_MARSHALLABLE(_c_) \
-extern unmarshall & operator>>(unmarshall &u, typename remove_reference<_c_>::type &a); \
-extern marshall & operator<<(marshall &m, const _c_ a);
-#define MARSHALLABLE(_c_) \
-inline unmarshall & operator>>(unmarshall &u, _c_ &a) { return u >> a._tuple_(); } \
-inline marshall & operator<<(marshall &m, const _c_ a) { return m << a._tuple_(); }
-
-// for plain old data
-#define MARSHALL_RAW_NETWORK_ORDER_AS(_c_, _d_) \
-marshall & operator<<(marshall &m, _c_ x) { _d_ y = hton((_d_)x); m.rawbytes(&y, sizeof(_d_)); return m; } \
-unmarshall & operator>>(unmarshall &u, _c_ &x) { _d_ y; u.rawbytes(&y, sizeof(_d_)); x = (_c_)ntoh(y); return u; }
-#define MARSHALL_RAW_NETWORK_ORDER(_c_) MARSHALL_RAW_NETWORK_ORDER_AS(_c_, _c_)
-
-FORWARD_MARSHALLABLE(request_header)
-ENDIAN_SWAPPABLE(request_header)
-
-FORWARD_MARSHALLABLE(reply_header)
-ENDIAN_SWAPPABLE(reply_header)
-
-// Template parameter pack expansion is not allowed in certain contexts, but
-// brace initializers (for instance, calls to constructors of empty structs)
-// are fair game.
-struct pass { template <typename... Args> inline pass(Args&&...) {} };
+//
+// Marshall and unmarshall objects
+//
class marshall {
private:
string buf_ = string(DEFAULT_RPC_SZ, 0); // Raw bytes buffer
size_t index_ = RPC_HEADER_SZ; // Read/write head position
- inline void reserve(size_t n) {
- if (index_+n > buf_.size())
- buf_.resize(index_+n);
- }
public:
template <typename... Args>
marshall(const Args&... args) {
}
void rawbytes(const void *p, size_t n) {
- reserve(n);
+ if (index_+n > buf_.size())
+ buf_.resize(index_+n);
copy((char *)p, (char *)p+n, &buf_[index_]);
index_ += n;
}
// with header
- operator string () const { return buf_.substr(0,index_); }
+ inline operator string() const { return buf_.substr(0,index_); }
// without header
- string content() { return buf_.substr(RPC_HEADER_SZ,index_-RPC_HEADER_SZ); }
-
- template <class T>
- void pack_header(const T &h) {
- VERIFY(sizeof(T)+sizeof(rpc_sz_t) <= RPC_HEADER_SZ);
+ inline string content() { return buf_.substr(RPC_HEADER_SZ,index_-RPC_HEADER_SZ); }
+
+ // letting S be a defaulted template parameter forces the compiler to
+ // delay looking up operator<<(marshall&, rpc_sz_t) until we define it
+ // (i.e. we define an operator for marshalling uint32_t)
+ template <class T, class S=rpc_sz_t> inline void
+ pack_header(const T & h) {
+ VERIFY(sizeof(T)+sizeof(S) <= RPC_HEADER_SZ);
size_t saved_sz = index_;
- index_ = sizeof(rpc_sz_t); // first 4 bytes hold length field
- *this << h;
+ index_ = 0;
+ *this << (S)(saved_sz - sizeof(S)) << (T)h;
index_ = saved_sz;
}
};
-FORWARD_MARSHALLABLE(bool);
-FORWARD_MARSHALLABLE(uint8_t);
-FORWARD_MARSHALLABLE(int8_t);
-FORWARD_MARSHALLABLE(uint16_t);
-FORWARD_MARSHALLABLE(int16_t);
-FORWARD_MARSHALLABLE(uint32_t);
-FORWARD_MARSHALLABLE(int32_t);
-FORWARD_MARSHALLABLE(size_t);
-FORWARD_MARSHALLABLE(uint64_t);
-FORWARD_MARSHALLABLE(int64_t);
-FORWARD_MARSHALLABLE(string &);
-
-template <class A> typename enable_if<is_iterable<A>::value, marshall>::type &
-operator<<(marshall &m, const A &x) {
- m << (unsigned int)x.size();
- for (const auto &a : x)
- m << a;
- return m;
-}
-
-template <class A, class B> marshall &
-operator<<(marshall &m, const pair<A,B> &d) {
- return m << d.first << d.second;
-}
-
-template<typename E>
-using enum_type_t = typename enable_if<is_enum<E>::value, typename underlying_type<E>::type>::type;
-template<typename E> constexpr inline enum_type_t<E> from_enum(E e) noexcept { return (enum_type_t<E>)e; }
-template<typename E> constexpr inline E to_enum(enum_type_t<E> value) noexcept { return (E)value; }
-
-template <class E> typename enable_if<is_enum<E>::value, marshall>::type &
-operator<<(marshall &m, E e) {
- return m << from_enum(e);
-}
-
-template <class E> typename enable_if<is_enum<E>::value, unmarshall>::type &
-operator>>(unmarshall &u, E &e);
-
class unmarshall {
private:
string buf_;
size_t index_ = 0;
bool ok_ = false;
- inline bool ensure(size_t n) {
- if (index_+n > buf_.size())
- ok_ = false;
- return ok_;
- }
public:
unmarshall() {}
unmarshall(const string &s, bool has_header)
bool okdone() const { return ok_ && index_ == buf_.size(); }
void rawbytes(void * t, size_t n) {
- VERIFY(ensure(n));
+ if (index_+n > buf_.size())
+ ok_ = false;
+ VERIFY(ok_);
copy(&buf_[index_], &buf_[index_+n], (char *)t);
index_ += n;
}
- template <class T>
- void unpack_header(T & h) {
- // first 4 bytes hold length field
+ template <class T> void
+ unpack_header(T & h) {
VERIFY(sizeof(T)+sizeof(rpc_sz_t) <= RPC_HEADER_SZ);
+ // first 4 bytes hold length field
index_ = sizeof(rpc_sz_t);
*this >> h;
index_ = RPC_HEADER_SZ;
template <class T> inline T grab() { T t; *this >> t; return t; }
};
-template <class A> typename enable_if<is_iterable<A>::value, unmarshall>::type &
-operator>>(unmarshall &u, A &x) {
- unsigned n = u.grab<unsigned>();
- x.clear();
- while (n--)
- x.emplace_back(u.grab<typename A::value_type>());
- return u;
-}
+//
+// Marshalling for plain old data
+//
-template <class A, class B> unmarshall &
-operator>>(unmarshall &u, map<A,B> &x) {
- unsigned n = u.grab<unsigned>();
- x.clear();
- while (n--)
- x.emplace(u.grab<pair<A,B>>());
- return u;
+#define MARSHALL_RAW_NETWORK_ORDER_AS(_c_, _d_) \
+inline marshall & operator<<(marshall &m, _c_ x) { _d_ y = hton((_d_)x); m.rawbytes(&y, sizeof(_d_)); return m; } \
+inline unmarshall & operator>>(unmarshall &u, _c_ &x) { _d_ y; u.rawbytes(&y, sizeof(_d_)); x = (_c_)ntoh(y); return u; }
+
+#define MARSHALL_RAW_NETWORK_ORDER(_c_) MARSHALL_RAW_NETWORK_ORDER_AS(_c_, _c_)
+
+MARSHALL_RAW_NETWORK_ORDER_AS(bool, uint8_t)
+MARSHALL_RAW_NETWORK_ORDER(uint8_t)
+MARSHALL_RAW_NETWORK_ORDER(int8_t)
+MARSHALL_RAW_NETWORK_ORDER(uint16_t)
+MARSHALL_RAW_NETWORK_ORDER(int16_t)
+MARSHALL_RAW_NETWORK_ORDER(uint32_t)
+MARSHALL_RAW_NETWORK_ORDER(int32_t)
+MARSHALL_RAW_NETWORK_ORDER_AS(size_t, uint32_t)
+MARSHALL_RAW_NETWORK_ORDER(uint64_t)
+MARSHALL_RAW_NETWORK_ORDER(int64_t)
+
+//
+// Marshalling for tuples (used to implement marshalling for structs)
+//
+
+// In order to iterate over the tuple elements, we first need a template
+// parameter pack containing the tuple's indices. The function templates named
+// *_imp below accept an empty tag struct as their last argument, and use its
+// template arguments to index the tuple. The operator<< overloads instantiate
+// the appropriate tag struct to make this possible.
+
+template <class... Args, size_t... Indices> inline marshall &
+tuple_marshall_imp(marshall & m, tuple<Args...> & t, tuple_indices<Indices...>) {
+ // Note that brace initialization is used for the empty structure "pack",
+ // forcing the comma-separated expressions expanded from the parameter pack
+ // to be evaluated in order. Order matters because the elements must be
+ // serialized consistently! The empty struct resulting from construction
+ // is discarded.
+ (void)pass{(m << get<Indices>(t))...};
+ return m;
}
-template <class A, class B> unmarshall &
-operator>>(unmarshall &u, pair<A,B> &d) {
- return u >> d.first >> d.second;
+template <class... Args> marshall &
+operator<<(marshall & m, tuple<Args...> && t) {
+ using Indices = typename make_tuple_indices<sizeof...(Args)>::type;
+ return tuple_marshall_imp(m, t, Indices());
}
-template <class E> typename enable_if<is_enum<E>::value, unmarshall>::type &
-operator>>(unmarshall &u, E &e) {
- e = to_enum<E>(u.grab<enum_type_t<E>>());
+template <class... Args, size_t... Indices> inline unmarshall &
+tuple_unmarshall_imp(unmarshall & u, tuple<Args &...> t, tuple_indices<Indices...>) {
+ (void)pass{(u >> get<Indices>(t))...};
return u;
}
-typedef function<int(unmarshall &, marshall &)> handler;
+template <class... Args> unmarshall &
+operator>>(unmarshall & u, tuple<Args &...> && t) {
+ using Indices = typename make_tuple_indices<sizeof...(Args)>::type;
+ return tuple_unmarshall_imp(u, t, Indices());
+}
//
-// Automatic marshalling wrappers for RPC handlers
+// Marshalling for structs or classes containing a MEMBERS declaration
//
-// PAI 2013/09/19
-// C++11 does neither of these two things for us:
-// 1) Declare variables using a parameter pack expansion, like so
-// Args... args;
-// 2) Call a function with a tuple of the arguments it expects
-//
-// We implement an 'invoke' function for functions of the RPC handler
-// signature, i.e. int(R & r, const Args...)
-//
-// One thing we need in order to accomplish this is a way to cause the compiler
-// to specialize 'invoke' with a parameter pack containing a list of indices
-// for the elements of the tuple. This will allow us to call the underlying
-// function with the exploded contents of the tuple. The empty type
-// tuple_indices<size_t...> accomplishes this. It will be passed in to
-// 'invoke' as a parameter which will be ignored, but its type will force the
-// compiler to specialize 'invoke' appropriately.
-
-// This class encapsulates the default response to runtime unmarshalling
-// failures. The templated wrappers below may optionally use a different
-// class.
-
-struct VerifyOnFailure {
- static inline int unmarshall_args_failure() {
- VERIFY(0);
- return 0;
- }
-};
+// Implements struct marshalling via tuple marshalling of members.
+#define MARSHALLABLE(_c_) \
+inline unmarshall & operator>>(unmarshall &u, _c_ &a) { return u >> a._tuple_(); } \
+inline marshall & operator<<(marshall &m, const _c_ a) { return m << a._tuple_(); }
-// Here's the implementation of 'invoke'. It could be more general, but this
-// meets our needs.
+// our first two marshallable structs...
+MARSHALLABLE(request_header)
+MARSHALLABLE(reply_header)
-// One for function pointers...
+//
+// Marshalling for STL containers
+//
-template <class F, class R, class RV, class args_type, size_t... Indices>
-typename enable_if<!is_member_function_pointer<F>::value, RV>::type
-invoke(RV, F f, void *, R & r, args_type & t, tuple_indices<Indices...>) {
- return f(r, move(get<Indices>(t))...);
+// this overload is visible for type A only if A::cbegin and A::cend exist
+template <class A> inline typename
+enable_if<is_const_iterable<A>::value, marshall>::type &
+operator<<(marshall &m, const A &x) {
+ m << (unsigned int)x.size();
+ for (const auto &a : x)
+ m << a;
+ return m;
}
-// And one for pointers to member functions...
-
-template <class F, class C, class RV, class R, class args_type, size_t... Indices>
-typename enable_if<is_member_function_pointer<F>::value, RV>::type
-invoke(RV, F f, C *c, R & r, args_type & t, tuple_indices<Indices...>) {
- return (c->*f)(r, move(get<Indices>(t))...);
+// visible for type A if A::emplace_back(a) makes sense
+template <class A> inline typename
+enable_if<supports_emplace_back<A>::value, unmarshall>::type &
+operator>>(unmarshall &u, A &x) {
+ unsigned n = u.grab<unsigned>();
+ x.clear();
+ while (n--)
+ x.emplace_back(u.grab<typename A::value_type>());
+ return u;
}
-// The class marshalled_func_imp uses partial template specialization to
-// implement the ::wrap static function. ::wrap takes a function pointer or a
-// pointer to a member function and returns a handler * object which
-// unmarshalls arguments, verifies successful unmarshalling, calls the supplied
-// function, and marshalls the response.
-
-template <class Functor, class Instance, class Signature,
- class ErrorHandler=VerifyOnFailure> struct marshalled_func_imp;
-
-// Here we specialize on the Signature template parameter to obtain the list of
-// argument types. Note that we do not assume that the Functor parameter has
-// the same pattern as Signature; this allows us to ignore the distinctions
-// between various types of callable objects at this level of abstraction.
-
-template <class F, class C, class ErrorHandler, class R, class RV, class... Args>
-struct marshalled_func_imp<F, C, RV(R&, Args...), ErrorHandler> {
- static inline handler *wrap(F f, C *c=nullptr) {
- // This type definition corresponds to an empty struct with
- // template parameters running from 0 up to (# args) - 1.
- using Indices = typename make_tuple_indices<sizeof...(Args)>::type;
- // This type definition represents storage for f's unmarshalled
- // arguments. decay is (most notably) stripping off const
- // qualifiers.
- using ArgsStorage = tuple<typename decay<Args>::type...>;
- // Allocate a handler (i.e. function) to hold the lambda
- // which will unmarshall RPCs and call f.
- return new handler([=](unmarshall &u, marshall &m) -> RV {
- // Unmarshall each argument with the correct type and store the
- // result in a tuple.
- ArgsStorage t = {u.grab<typename decay<Args>::type>()...};
- // Verify successful unmarshalling of the entire input stream.
- if (!u.okdone())
- return (RV)ErrorHandler::unmarshall_args_failure();
- // Allocate space for the RPC response -- will be passed into the
- // function as an lvalue reference.
- R r;
- // Perform the invocation. Note that Indices() calls the default
- // constructor of the empty struct with the special template
- // parameters.
- RV b = invoke(RV(), f, c, r, t, Indices());
- // Marshall the response.
- m << r;
- // Make like a tree.
- return b;
- });
- }
-};
-
-// More partial template specialization shenanigans to reduce the number of
-// parameters which must be provided explicitly and to support a few common
-// callable types. C++11 doesn't allow partial function template
-// specialization, so we use classes (structs).
-
-template <class Functor, class ErrorHandler=VerifyOnFailure,
- class Signature=Functor> struct marshalled_func;
-
-template <class F, class ErrorHandler, class RV, class... Args>
-struct marshalled_func<F, ErrorHandler, RV(*)(Args...)> :
- public marshalled_func_imp<F, void, RV(Args...), ErrorHandler> {};
-
-template <class F, class ErrorHandler, class RV, class C, class... Args>
-struct marshalled_func<F, ErrorHandler, RV(C::*)(Args...)> :
- public marshalled_func_imp<F, C, RV(Args...), ErrorHandler> {};
+// std::pair<A, B>
+template <class A, class B> inline marshall &
+operator<<(marshall &m, const pair<A,B> &d) {
+ return m << d.first << d.second;
+}
-template <class F, class ErrorHandler, class Signature>
-struct marshalled_func<F, ErrorHandler, function<Signature>> :
- public marshalled_func_imp<F, void, Signature, ErrorHandler> {};
+template <class A, class B> inline unmarshall &
+operator>>(unmarshall &u, pair<A,B> &d) {
+ return u >> d.first >> d.second;
+}
-template <class... Args, size_t... Indices> unmarshall &
-tuple_unmarshall_imp(unmarshall & u, tuple<Args &...> t, tuple_indices<Indices...>) {
- (void)pass{(u >> get<Indices>(t))...};
+// std::map<A, B>
+template <class A, class B> inline unmarshall &
+operator>>(unmarshall &u, map<A,B> &x) {
+ unsigned n = u.grab<unsigned>();
+ x.clear();
+ while (n--)
+ x.emplace(u.grab<pair<A,B>>());
return u;
}
-template <class... Args> unmarshall &
-operator>>(unmarshall & u, tuple<Args &...> && t) {
- using Indices = typename make_tuple_indices<sizeof...(Args)>::type;
- return tuple_unmarshall_imp(u, t, Indices());
+// std::string
+inline marshall & operator<<(marshall &m, const string &s) {
+ m << (uint32_t)s.size();
+ m.rawbytes(s.data(), s.size());
+ return m;
}
-template <class... Args, size_t... Indices> marshall &
-tuple_marshall_imp(marshall & m, tuple<Args...> & t, tuple_indices<Indices...>) {
- (void)pass{(m << get<Indices>(t))...};
- return m;
+inline unmarshall & operator>>(unmarshall &u, string &s) {
+ uint32_t sz = u.grab<uint32_t>();
+ if (u.ok()) {
+ s.resize(sz);
+ u.rawbytes(&s[0], sz);
+ }
+ return u;
}
-template <class... Args> marshall &
-operator<<(marshall & m, tuple<Args...> && t) {
- using Indices = typename make_tuple_indices<sizeof...(Args)>::type;
- return tuple_marshall_imp(m, t, Indices());
+//
+// Marshalling for strongly-typed enums
+//
+
+template <class E> typename enable_if<is_enum<E>::value, marshall>::type &
+operator<<(marshall &m, E e) {
+ return m << from_enum(e);
}
-MARSHALLABLE(request_header)
-MARSHALLABLE(reply_header)
+template <class E> typename enable_if<is_enum<E>::value, unmarshall>::type &
+operator>>(unmarshall &u, E &e) {
+ e = to_enum<E>(u.grab<enum_type_t<E>>());
+ return u;
+}
#endif
--- /dev/null
+#ifndef marshall_wrap_h
+#define marshall_wrap_h
+
+#include "marshall.h"
+
+typedef function<int(unmarshall &, marshall &)> handler;
+
+//
+// Automatic marshalling wrappers for RPC handlers
+//
+
+// PAI 2013/09/19
+// C++11 does neither of these two things for us:
+// 1) Declare variables using a parameter pack expansion, like so
+// Args... args;
+// 2) Call a function with a tuple of the arguments it expects
+//
+// We implement an 'invoke' function for functions of the RPC handler
+// signature, i.e. int(R & r, const Args...)
+//
+// One thing we need in order to accomplish this is a way to cause the compiler
+// to specialize 'invoke' with a parameter pack containing a list of indices
+// for the elements of the tuple. This will allow us to call the underlying
+// function with the exploded contents of the tuple. The empty type
+// tuple_indices<size_t...> accomplishes this. It will be passed in to
+// 'invoke' as a parameter which will be ignored, but its type will force the
+// compiler to specialize 'invoke' appropriately.
+
+// This class encapsulates the default response to runtime unmarshalling
+// failures. The templated wrappers below may optionally use a different
+// class.
+
+struct VerifyOnFailure {
+ static inline int unmarshall_args_failure() {
+ VERIFY(0);
+ return 0;
+ }
+};
+
+// Here's the implementation of 'invoke'. It could be more general, but this
+// meets our needs.
+
+// One for function pointers...
+
+template <class F, class R, class RV, class args_type, size_t... Indices>
+typename enable_if<!is_member_function_pointer<F>::value, RV>::type
+invoke(RV, F f, void *, R & r, args_type & t, tuple_indices<Indices...>) {
+ return f(r, move(get<Indices>(t))...);
+}
+
+// And one for pointers to member functions...
+
+template <class F, class C, class RV, class R, class args_type, size_t... Indices>
+typename enable_if<is_member_function_pointer<F>::value, RV>::type
+invoke(RV, F f, C *c, R & r, args_type & t, tuple_indices<Indices...>) {
+ return (c->*f)(r, move(get<Indices>(t))...);
+}
+
+// The class marshalled_func_imp uses partial template specialization to
+// implement the ::wrap static function. ::wrap takes a function pointer or a
+// pointer to a member function and returns a handler * object which
+// unmarshalls arguments, verifies successful unmarshalling, calls the supplied
+// function, and marshalls the response.
+
+template <class Functor, class Instance, class Signature,
+ class ErrorHandler=VerifyOnFailure> struct marshalled_func_imp;
+
+// Here we specialize on the Signature template parameter to obtain the list of
+// argument types. Note that we do not assume that the Functor parameter has
+// the same pattern as Signature; this allows us to ignore the distinctions
+// between various types of callable objects at this level of abstraction.
+
+template <class F, class C, class ErrorHandler, class R, class RV, class... Args>
+struct marshalled_func_imp<F, C, RV(R&, Args...), ErrorHandler> {
+ static inline handler *wrap(F f, C *c=nullptr) {
+ // This type definition corresponds to an empty struct with
+ // template parameters running from 0 up to (# args) - 1.
+ using Indices = typename make_tuple_indices<sizeof...(Args)>::type;
+ // This type definition represents storage for f's unmarshalled
+ // arguments. decay is (most notably) stripping off const
+ // qualifiers.
+ using ArgsStorage = tuple<typename decay<Args>::type...>;
+ // Allocate a handler (i.e. function) to hold the lambda
+ // which will unmarshall RPCs and call f.
+ return new handler([=](unmarshall &u, marshall &m) -> RV {
+ // Unmarshall each argument with the correct type and store the
+ // result in a tuple.
+ ArgsStorage t = {u.grab<typename decay<Args>::type>()...};
+ // Verify successful unmarshalling of the entire input stream.
+ if (!u.okdone())
+ return (RV)ErrorHandler::unmarshall_args_failure();
+ // Allocate space for the RPC response -- will be passed into the
+ // function as an lvalue reference.
+ R r;
+ // Perform the invocation. Note that Indices() calls the default
+ // constructor of the empty struct with the special template
+ // parameters.
+ RV b = invoke(RV(), f, c, r, t, Indices());
+ // Marshall the response.
+ m << r;
+ // Make like a tree.
+ return b;
+ });
+ }
+};
+
+// More partial template specialization shenanigans to reduce the number of
+// parameters which must be provided explicitly and to support a few common
+// callable types. C++11 doesn't allow partial function template
+// specialization, so we use classes (structs).
+
+template <class Functor, class ErrorHandler=VerifyOnFailure,
+ class Signature=Functor> struct marshalled_func;
+
+template <class F, class ErrorHandler, class RV, class... Args>
+struct marshalled_func<F, ErrorHandler, RV(*)(Args...)> :
+ public marshalled_func_imp<F, void, RV(Args...), ErrorHandler> {};
+
+template <class F, class ErrorHandler, class RV, class C, class... Args>
+struct marshalled_func<F, ErrorHandler, RV(C::*)(Args...)> :
+ public marshalled_func_imp<F, C, RV(Args...), ErrorHandler> {};
+
+template <class F, class ErrorHandler, class Signature>
+struct marshalled_func<F, ErrorHandler, function<Signature>> :
+ public marshalled_func_imp<F, void, Signature, ErrorHandler> {};
+
+#endif
projects / invirt/third/libt4.git / commitdiff
