diff options
Diffstat (limited to 'indra')
| -rw-r--r-- | indra/llcommon/lleventdispatcher.cpp | 183 | ||||
| -rw-r--r-- | indra/llcommon/lleventdispatcher.h | 93 |
2 files changed, 216 insertions, 60 deletions
diff --git a/indra/llcommon/lleventdispatcher.cpp b/indra/llcommon/lleventdispatcher.cpp index 8e20d7184a..d10cf16b88 100644 --- a/indra/llcommon/lleventdispatcher.cpp +++ b/indra/llcommon/lleventdispatcher.cpp @@ -744,32 +744,44 @@ std::ostream& operator<<(std::ostream& out, const LLEventDispatcher& self) *****************************************************************************/ std::string LLDispatchListener::mReplyKey{ "reply" }; -/*==========================================================================*| - TODO: -* When process() finds name.isArray(), construct response array from - dispatching each call -- args must also be (array of args structures) - (could also construct response map, IF array contains unique names) -* When process() finds name.isMap(), construct response map from dispatching - each call -- value of each key is its args struct -- argskey ignored -- - note, caller can't care about order -* Possible future transactional behavior: look up all names before calling any -|*==========================================================================*/ bool LLDispatchListener::process(const LLSD& event) const { - // Collecting errors is only meaningful with a reply key. Without one, if - // an error occurs, let the exception propagate. - auto returned = call("", event, (! event.has(mReplyKey))); - std::string& error{ returned.first }; - LLSD& result{ returned.second }; + // Decide what to do based on the incoming value of the specified dispatch + // key. + LLSD name{ event[getDispatchKey()] }; + if (name.isMap()) + { + call_map(name, event); + } + else if (name.isArray()) + { + call_array(name, event); + } + else + { + call_one(name, event); + } + return false; +} - if (! error.empty()) +void LLDispatchListener::call_one(const LLSD& name, const LLSD& event) const +{ + LLSD result; + try { - // Here there was an error and the incoming event has mReplyKey -- - // else DispatchError would already have propagated out of the call() - // above. Reply with a map containing an "error" key explaining the - // problem. - reply(llsd::map("error", error), event); - return false; + result = (*this)(event); + } + catch (const DispatchError& err) + { + if (! event.has(mReplyKey)) + { + // Without a reply key, let the exception propagate. + throw; + } + + // Here there was an error and the incoming event has mReplyKey. Reply + // with a map containing an "error" key explaining the problem. + return reply(llsd::map("error", err.what()), event); } // We seem to have gotten a valid result. But we don't know whether the @@ -785,40 +797,127 @@ bool LLDispatchListener::process(const LLSD& event) const } reply(result, event); } - return false; } -// Pass empty name to call LLEventDispatcher::operator()(const LLSD&), -// non-empty name to call operator()(const std::string&, const LLSD&). -// Returns (empty string, return value) on successful call. -// Returns (error message, undefined) if error and 'exception' is false. -// Throws DispatchError if error and 'exception' is true. -std::pair<std::string, LLSD> LLDispatchListener::call(const std::string& name, const LLSD& event, - bool exception) const +void LLDispatchListener::call_map(const LLSD& reqmap, const LLSD& event) const { - try + // LLSD map containing returned values + LLSD result; + // collect any error messages here + std::ostringstream errors; + const char* delim = ""; + + for (const auto& pair : llsd::inMap(reqmap)) + { + const LLSD::String& name{ pair.first }; + const LLSD& args{ pair.second }; + try + { + // With this form, capture return value even if undefined: + // presence of the key in the response map can be used to detect + // which request keys succeeded. + result[name] = (*this)(name, args); + } + catch (const DispatchError& err) + { + // collect message in 'errors', with hint as to which request map + // entry failed + errors << delim << err.what() << " (" << getDispatchKey() + << '[' << name << "])"; + delim = "\n"; + } + } + + // so, were there any errors? + std::string error = errors.str(); + if (! error.empty()) { - if (name.empty()) + if (! event.has(mReplyKey)) { - // unless this throws, return (empty string, real return value) - return { {}, (*this)(event) }; + // can't send reply, throw + sCallFail<DispatchError>(error); } else { - // unless this throws, return (empty string, real return value) - return { {}, (*this)(name, event) }; + // reply key present + result["error"] = error; } } - catch (const DispatchError& err) + + reply(result, event); +} + +void LLDispatchListener::call_array(const LLSD& reqarray, const LLSD& event) const +{ + // LLSD array containing returned values + LLSD results; + // arguments array, if present -- const because, if it's shorter than + // reqarray, we don't want to grow it + const LLSD argsarray{ event[getArgsKey()] }; + // error message, if any + std::string error; + + // classic index loop because we need the index + for (size_t i = 0, size = reqarray.size(); i < size; ++i) + { + const auto& reqentry{ reqarray[i] }; + std::string name; + LLSD args; + if (reqentry.isString()) + { + name = reqentry.asString(); + args = argsarray[i]; + } + else if (reqentry.isArray() && reqentry.size() == 2 && reqentry[0].isString()) + { + name = reqentry[0].asString(); + args = reqentry[1]; + } + else + { + // reqentry isn't in either of the documented forms + error = stringize(*this, ": ", getDispatchKey(), '[', i, "] ", + reqentry, " unsupported"); + break; + } + + // reqentry is one of the valid forms, got name and args + try + { + // With this form, capture return value even if undefined + results.append((*this)(name, args)); + } + catch (const DispatchError& err) + { + // append hint as to which requentry produced the error + error = stringize(err.what(), " (", getDispatchKey(), '[', i, ']'); + break; + } + } + + LLSD result; + // was there an error? + if (! error.empty()) { - if (exception) + if (! event.has(mReplyKey)) { - // Caller asked for an exception on error. Oblige. - throw; + // can't send reply, throw + sCallFail<DispatchError>(error); + } + else + { + // reply key present + result["error"] = error; } - // Caller does NOT want an exception: return (error message, undefined) - return { err.what(), LLSD() }; } + + // wrap the results array as response map "data" key, as promised + if (results.isDefined()) + { + result["data"] = results; + } + + reply(result, event); } void LLDispatchListener::reply(const LLSD& reply, const LLSD& request) const diff --git a/indra/llcommon/lleventdispatcher.h b/indra/llcommon/lleventdispatcher.h index a348a6660f..5ab860b6dd 100644 --- a/indra/llcommon/lleventdispatcher.h +++ b/indra/llcommon/lleventdispatcher.h @@ -341,6 +341,8 @@ public: /// Retrieve the LLSD key we use for one-arg <tt>operator()</tt> method std::string getDispatchKey() const { return mKey; } + /// Retrieve the LLSD key we use for non-map arguments + std::string getArgsKey() const { return mArgskey; } /// description of this instance's leaf class and description friend std::ostream& operator<<(std::ostream&, const LLEventDispatcher&); @@ -363,6 +365,8 @@ private: void addFail(const std::string& name, const std::string& classname) const; LLSD try_call(const std::string& key, const std::string& name, const LLSD& event) const; + +protected: // raise specified EXCEPTION with specified stringize(ARGS) template <typename EXCEPTION, typename... ARGS> void callFail(ARGS&&... args) const; @@ -370,6 +374,7 @@ private: static void sCallFail(ARGS&&... args); +private: std::string mDesc, mKey, mArgskey; DispatchMap mDispatch; @@ -521,12 +526,12 @@ LLEventDispatcher::make_invoker(Method f, const InstanceGetter& getter) /** * Bundle an LLEventPump and a listener with an LLEventDispatcher. A class * that contains (or derives from) LLDispatchListener need only specify the - * LLEventPump name and dispatch key, and add() its methods. Incoming events - * will automatically be dispatched. + * LLEventPump name and dispatch key, and add() its methods. Each incoming + * event ("request") will automatically be dispatched. * - * If the incoming event contains a "reply" key specifying the LLSD::String - * name of an LLEventPump to which to respond, LLDispatchListener will attempt - * to send a response to that LLEventPump. + * If the request contains a "reply" key specifying the LLSD::String name of + * an LLEventPump to which to respond, LLDispatchListener will attempt to send + * a response to that LLEventPump. * * If some error occurs (e.g. nonexistent callable name, wrong params) and * "reply" is present, LLDispatchListener will send a response map to the @@ -542,14 +547,70 @@ LLEventDispatcher::make_invoker(Method f, const InstanceGetter& getter) * * If the target callable returns a type convertible to LLSD (and, if it * directly returns LLSD, the return value isDefined()), and if a "reply" key - * is present in the incoming event, LLDispatchListener will post the returned - * value to the "reply" LLEventPump. If the returned value is an LLSD map, it - * will merge the echoed "reqid" key into the map and send that. Otherwise, it - * will send an LLSD map containing "reqid" and a "data" key whose value is - * the value returned by the target callable. + * is present in the request, LLDispatchListener will post the returned value + * to the "reply" LLEventPump. If the returned value is an LLSD map, it will + * merge the echoed "reqid" key into the map and send that. Otherwise, it will + * send an LLSD map containing "reqid" and a "data" key whose value is the + * value returned by the target callable. * * (It is inadvisable for a target callable to return an LLSD map containing - * keys "reqid" or "error", as that will confuse the invoker.) + * keys "data", "reqid" or "error", as that will confuse the invoker.) + * + * Normally the request will specify the value of the dispatch key as an + * LLSD::String naming the target callable. Alternatively, several such calls + * may be "batched" as described below. + * + * If the value of the dispatch key is itself an LLSD map (a "request map"), + * each map key must name a target callable, and the value of that key must + * contain the parameters to pass to that callable. If a "reply" key is + * present in the request, the response map will contain a key for each of the + * keys in the request map. The value of every such key is the value returned + * by the target callable. + * + * (Avoid naming any target callable in the LLDispatchListener "data", "reqid" + * or "error" to avoid confusion.) + * + * Since LLDispatchListener calls the target callables specified by a request + * map in arbitrary order, this form assumes that the batched operations are + * independent of each other. LLDispatchListener will attempt every call, even + * if some attempts produce errors. If any keys in the request map produce + * errors, LLDispatchListener builds a composite error message string + * collecting the relevant messages. The corresponding keys will be missing + * from the response map. As in the single-callable case, absent a "reply" key + * in the request, this error message will be thrown as a DispatchError. With + * a "reply" key, it will be returned as the value of the "error" key. This + * form can indicate partial success: some request keys might have + * return-value keys in the response, others might have message text in the + * "error" key. + * + * If a specific call sequence is required, the value of the dispatch key may + * instead be an LLSD array (a "request array"). Each entry in the request + * array ("request entry") names a target callable, to be called in + * array-index sequence. Arguments for that callable may be specified in + * either of two ways. + * + * The request entry may itself be a two-element array, whose [0] is an + * LLSD::String naming the target callable and whose [1] contains the + * arguments to pass to that callable. + * + * Alternatively, the request entry may be an LLSD::String naming the target + * callable, in which case the request must contain an arguments key (optional + * third constructor argument) whose value is an array matching the request + * array. The arguments for the request entry's target callable are found at + * the same index in the arguments key array. + * + * If a "reply" key is present in the request, the response map will contain a + * "data" key whose value is an array. Each entry in that response array will + * contain the result from the corresponding request entry. + * + * This form assumes that any of the batched operations might depend on the + * success of a previous operation in the same batch. The @emph first error + * encountered will terminate the sequence. The error message might either be + * thrown as DispatchError or, given a "reply" key, returned as the "error" + * key in the response map. This form can indicate partial success: the first + * few request entries might have return-value entries in the "data" response + * array, along with an "error" key whose value is the error message that + * stopped the sequence. */ // Instead of containing an LLEventStream, LLDispatchListener derives from it. // This allows an LLEventPumps::PumpFactory to return a pointer to an @@ -568,13 +629,9 @@ public: private: bool process(const LLSD& event) const; - // Pass empty name to call LLEventDispatcher::operator()(const LLSD&), - // non-empty name to call operator()(const std::string&, const LLSD&). - // Returns (empty string, return value) on successful call. - // Returns (error message, undefined) if error and 'exception' is false. - // Throws DispatchError if error and 'exception' is true. - std::pair<std::string, LLSD> call(const std::string& name, const LLSD& event, - bool exception) const; + void call_one(const LLSD& name, const LLSD& event) const; + void call_map(const LLSD& reqmap, const LLSD& event) const; + void call_array(const LLSD& reqarray, const LLSD& event) const; void reply(const LLSD& reply, const LLSD& request) const; LLTempBoundListener mBoundListener; |