diff options
Diffstat (limited to 'indra/llcommon/lleventdispatcher.cpp')
| -rw-r--r-- | indra/llcommon/lleventdispatcher.cpp | 428 |
1 files changed, 234 insertions, 194 deletions
diff --git a/indra/llcommon/lleventdispatcher.cpp b/indra/llcommon/lleventdispatcher.cpp index e7e73125a7..7e5723c503 100644 --- a/indra/llcommon/lleventdispatcher.cpp +++ b/indra/llcommon/lleventdispatcher.cpp @@ -43,21 +43,10 @@ #include "llexception.h" #include "llsdutil.h" #include "stringize.h" +#include <iomanip> // std::quoted() #include <memory> // std::auto_ptr /***************************************************************************** -* DispatchError -*****************************************************************************/ -struct DispatchError: public LLException -{ - // template constructor involving strings passes all arguments to - // stringize() to construct LLException's what() string - template <typename... ARGS> - DispatchError(const std::string& arg0, ARGS&&... args): - LLException(stringize(arg0, std::forward<ARGS>(args)...)) {} -}; - -/***************************************************************************** * LLSDArgsMapper *****************************************************************************/ /** @@ -109,7 +98,7 @@ struct DispatchError: public LLException * - Holes are filled with the default values. * - Any remaining holes constitute an error. */ -class LL_COMMON_API LLSDArgsMapper +class LL_COMMON_API LLEventDispatcher::LLSDArgsMapper { public: /// Accept description of function: function name, param names, param @@ -122,6 +111,8 @@ public: private: static std::string formatlist(const LLSD&); + template <typename... ARGS> + void callFail(ARGS&&... args) const; // The function-name string is purely descriptive. We want error messages // to be able to indicate which function's LLSDArgsMapper has the problem. @@ -141,15 +132,16 @@ private: FilledVector _has_dft; }; -LLSDArgsMapper::LLSDArgsMapper(const std::string& function, - const LLSD& names, const LLSD& defaults): +LLEventDispatcher::LLSDArgsMapper::LLSDArgsMapper(const std::string& function, + const LLSD& names, + const LLSD& defaults): _function(function), _names(names), _has_dft(names.size()) { if (! (_names.isUndefined() || _names.isArray())) { - LLTHROW(DispatchError(function, " names must be an array, not ", names)); + callFail(" names must be an array, not ", names); } auto nparams(_names.size()); // From _names generate _indexes. @@ -172,8 +164,7 @@ LLSDArgsMapper::LLSDArgsMapper(const std::string& function, // defaults is a (possibly empty) array. Right-align it with names. if (ndefaults > nparams) { - LLTHROW(DispatchError(function, " names array ", names, - " shorter than defaults array ", defaults)); + callFail(" names array ", names, " shorter than defaults array ", defaults); } // Offset by which we slide defaults array right to right-align with @@ -210,23 +201,20 @@ LLSDArgsMapper::LLSDArgsMapper(const std::string& function, } if (bogus.size()) { - LLTHROW(DispatchError(function, " defaults specified for nonexistent params ", - formatlist(bogus))); + callFail(" defaults specified for nonexistent params ", formatlist(bogus)); } } else { - LLTHROW(DispatchError(function, " defaults must be a map or an array, not ", - defaults)); + callFail(" defaults must be a map or an array, not ", defaults); } } -LLSD LLSDArgsMapper::map(const LLSD& argsmap) const +LLSD LLEventDispatcher::LLSDArgsMapper::map(const LLSD& argsmap) const { if (! (argsmap.isUndefined() || argsmap.isMap() || argsmap.isArray())) { - LLTHROW(DispatchError(_function, " map() needs a map or array, not ", - argsmap)); + callFail(" map() needs a map or array, not ", argsmap); } // Initialize the args array. Indexing a non-const LLSD array grows it // to appropriate size, but we don't want to resize this one on each @@ -323,15 +311,14 @@ LLSD LLSDArgsMapper::map(const LLSD& argsmap) const // by argsmap, that's a problem. if (unfilled.size()) { - LLTHROW(DispatchError(_function, " missing required arguments ", - formatlist(unfilled), " from ", argsmap)); + callFail(" missing required arguments ", formatlist(unfilled), " from ", argsmap); } // done return args; } -std::string LLSDArgsMapper::formatlist(const LLSD& list) +std::string LLEventDispatcher::LLSDArgsMapper::formatlist(const LLSD& list) { std::ostringstream out; const char* delim = ""; @@ -344,14 +331,26 @@ std::string LLSDArgsMapper::formatlist(const LLSD& list) return out.str(); } +template <typename... ARGS> +void LLEventDispatcher::LLSDArgsMapper::callFail(ARGS&&... args) const +{ + LLEventDispatcher::sCallFail<LLEventDispatcher::DispatchError> + (_function, std::forward<ARGS>(args)...); +} + /***************************************************************************** * LLEventDispatcher *****************************************************************************/ LLEventDispatcher::LLEventDispatcher(const std::string& desc, const std::string& key): + LLEventDispatcher(desc, key, "args") +{} + +LLEventDispatcher::LLEventDispatcher(const std::string& desc, const std::string& key, + const std::string& argskey): mDesc(desc), - mKey(key) -{ -} + mKey(key), + mArgskey(argskey) +{} LLEventDispatcher::~LLEventDispatcher() { @@ -375,20 +374,21 @@ struct LLEventDispatcher::LLSDDispatchEntry: public LLEventDispatcher::DispatchE Callable mFunc; LLSD mRequired; - virtual LLSD call(const std::string& desc, const LLSD& event) const + LLSD call(const std::string& desc, const LLSD& event, bool, const std::string&) const override { // Validate the syntax of the event itself. std::string mismatch(llsd_matches(mRequired, event)); if (! mismatch.empty()) { - LLTHROW(DispatchError(desc, ": bad request: ", mismatch)); + LLEventDispatcher::sCallFail<LLEventDispatcher::DispatchError> + (desc, ": bad request: ", mismatch); } // Event syntax looks good, go for it! mFunc(event); return {}; } - virtual LLSD addMetadata(LLSD meta) const + LLSD addMetadata(LLSD meta) const override { meta["required"] = mRequired; return meta; @@ -401,16 +401,35 @@ struct LLEventDispatcher::LLSDDispatchEntry: public LLEventDispatcher::DispatchE */ struct LLEventDispatcher::ParamsDispatchEntry: public LLEventDispatcher::DispatchEntry { - ParamsDispatchEntry(const std::string& desc, const invoker_function& func): + ParamsDispatchEntry(const std::string& name, const std::string& desc, + const invoker_function& func): DispatchEntry(desc), + mName(name), mInvoker(func) {} + std::string mName; invoker_function mInvoker; - virtual LLSD call(const std::string&, const LLSD& event) const + LLSD call(const std::string&, const LLSD& event, bool, const std::string&) const override + { + try + { + return mInvoker(event); + } + catch (const LL::apply_error& err) + { + // could hit runtime errors with LL::apply() + return callFail(err.what()); + } + } + + template <typename... ARGS> + LLSD callFail(ARGS&&... args) const { - return mInvoker(event); + LLEventDispatcher::sCallFail<LLEventDispatcher::DispatchError>(mName, ": ", std::forward<ARGS>(args)...); + // pacify the compiler + return {}; } }; @@ -420,15 +439,48 @@ struct LLEventDispatcher::ParamsDispatchEntry: public LLEventDispatcher::Dispatc */ struct LLEventDispatcher::ArrayParamsDispatchEntry: public LLEventDispatcher::ParamsDispatchEntry { - ArrayParamsDispatchEntry(const std::string& desc, const invoker_function& func, - LLSD::Integer arity): - ParamsDispatchEntry(desc, func), + ArrayParamsDispatchEntry(const std::string& name, const std::string& desc, + const invoker_function& func, LLSD::Integer arity): + ParamsDispatchEntry(name, desc, func), mArity(arity) {} LLSD::Integer mArity; - virtual LLSD addMetadata(LLSD meta) const + LLSD call(const std::string& desc, const LLSD& event, bool fromMap, const std::string& argskey) const override + { +// std::string context { stringize(desc, "(", event, ") with argskey ", std::quoted(argskey), ": ") }; + // Whether we try to extract arguments from 'event' depends on whether + // the LLEventDispatcher consumer called one of the (name, event) + // methods (! fromMap) or one of the (event) methods (fromMap). If we + // were called with (name, event), the passed event must itself be + // suitable to pass to the registered callable, no args extraction + // required or even attempted. Only if called with plain (event) do we + // consider extracting args from that event. Initially assume 'event' + // itself contains the arguments. + LLSD args{ event }; + if (fromMap) + { + if (mArity) + { + // We only require/retrieve argskey if the target function + // isn't nullary. For all others, since we require an LLSD + // array, we must have an argskey. + if (argskey.empty()) + { + return callFail("LLEventDispatcher has no args key"); + } + if ((! event.has(argskey))) + { + return callFail("missing required key ", std::quoted(argskey)); + } + args = event[argskey]; + } + } + return ParamsDispatchEntry::call(desc, args, fromMap, argskey); + } + + LLSD addMetadata(LLSD meta) const override { LLSD array(LLSD::emptyArray()); // Resize to number of arguments required @@ -449,7 +501,7 @@ struct LLEventDispatcher::MapParamsDispatchEntry: public LLEventDispatcher::Para MapParamsDispatchEntry(const std::string& name, const std::string& desc, const invoker_function& func, const LLSD& params, const LLSD& defaults): - ParamsDispatchEntry(desc, func), + ParamsDispatchEntry(name, desc, func), mMapper(name, params, defaults), mRequired(LLSD::emptyMap()) { @@ -493,14 +545,25 @@ struct LLEventDispatcher::MapParamsDispatchEntry: public LLEventDispatcher::Para LLSD mRequired; LLSD mOptional; - virtual LLSD call(const std::string& desc, const LLSD& event) const + LLSD call(const std::string& desc, const LLSD& event, bool fromMap, const std::string& argskey) const override { - // Just convert from LLSD::Map to LLSD::Array using mMapper, then pass - // to base-class call() method. - return ParamsDispatchEntry::call(desc, mMapper.map(event)); + // by default, pass the whole event as the arguments map + LLSD args{ event }; + // Were we called by one of the (event) methods (instead of the (name, + // event) methods), do we have an argskey, and does the incoming event + // have that key? + if (fromMap && (! argskey.empty()) && event.has(argskey)) + { + // if so, extract the value of argskey from the incoming event, + // and use that as the arguments map + args = event[argskey]; + } + // Now convert args from LLSD map to LLSD array using mMapper, then + // pass to base-class call() method. + return ParamsDispatchEntry::call(desc, mMapper.map(args), fromMap, argskey); } - virtual LLSD addMetadata(LLSD meta) const + LLSD addMetadata(LLSD meta) const override { meta["required"] = mRequired; meta["optional"] = mOptional; @@ -513,7 +576,11 @@ void LLEventDispatcher::addArrayParamsDispatchEntry(const std::string& name, const invoker_function& invoker, LLSD::Integer arity) { - mDispatch.emplace(name, new ArrayParamsDispatchEntry(desc, invoker, arity)); + // The first parameter to ArrayParamsDispatchEntry is solely for error + // messages. Identify our instance and this entry. + mDispatch.emplace( + name, + new ArrayParamsDispatchEntry(stringize(*this, '[', name, ']'), desc, invoker, arity)); } void LLEventDispatcher::addMapParamsDispatchEntry(const std::string& name, @@ -522,7 +589,11 @@ void LLEventDispatcher::addMapParamsDispatchEntry(const std::string& name, const LLSD& params, const LLSD& defaults) { - mDispatch.emplace(name, new MapParamsDispatchEntry(name, desc, invoker, params, defaults)); + // Pass instance info as well as this entry name for error messages. + mDispatch.emplace( + name, + new MapParamsDispatchEntry(stringize(*this, '[', name, ']'), + desc, invoker, params, defaults)); } /// Register a callable by name @@ -546,174 +617,101 @@ bool LLEventDispatcher::remove(const std::string& name) /// Call a registered callable with an explicitly-specified name. It is an /// error if no such callable exists. -void LLEventDispatcher::operator()(const std::string& name, const LLSD& event) const +LLSD LLEventDispatcher::operator()(const std::string& name, const LLSD& event) const { - std::string error{ try_call_log(std::string(), name, event) }; - if (! error.empty()) - { - callFail(event, error); - } + return try_call(std::string(), name, event); } -/// Extract the @a key value from the incoming @a event, and call the callable -/// whose name is specified by that map @a key. It is an error if no such -/// callable exists. -void LLEventDispatcher::operator()(const LLSD& event) const +bool LLEventDispatcher::try_call(const std::string& name, const LLSD& event) const { - std::string error{ try_call_log(mKey, event[mKey], event) }; - if (! error.empty()) + try { - callFail(event, error); + try_call(std::string(), name, event); + return true; } -} - -void LLEventDispatcher::callFail(const LLSD& event, const std::string& msg) const -{ - // pass back a response that includes an "error" key with the message. - reply(llsd::map("error", msg), event); -} - -void LLEventDispatcher::reply(const LLSD& response, const LLSD& event) const -{ - static LLSD::String key{ "reply" }; - if (event.has(key)) + // Note that we don't catch the generic DispatchError, only the specific + // DispatchMissing. try_call() only promises to return false if the + // specified callable name isn't found -- not for general errors. + catch (const DispatchMissing&) { - // Oh good, the incoming event specifies a reply pump -- pass back - // our response. - sendReply(response, event, key); + return false; } } -bool LLEventDispatcher::try_call(const LLSD& event) const -{ - return try_call_log(mKey, event[mKey], event).empty(); -} - -/*==========================================================================*| - TODO: - -* When mInvoker returns result.isDefined(), sendReply(llsd::map("data", result)) -* When try_call finds name.isArray(), construct response array from - dispatching each call, sendReply() as above -* When try_call finds name.isMap(), construct response map from dispatching - each call, sendReply() as above -- note, caller can't care about order -* Possible future transactional behavior: look up all names before calling any - -|*==========================================================================*/ -bool LLEventDispatcher::try_call(const std::string& name, const LLSD& event) const +/// Extract the @a key value from the incoming @a event, and call the callable +/// whose name is specified by that map @a key. It is an error if no such +/// callable exists. +LLSD LLEventDispatcher::operator()(const LLSD& event) const { - return try_call_log(std::string(), name, event).empty(); + return try_call(mKey, event[mKey], event); } -std::string LLEventDispatcher::try_call_log(const std::string& key, const LLSD& name, - const LLSD& event) const +bool LLEventDispatcher::try_call(const LLSD& event) const { - std::string error{ try_call(key, name, event) }; - if (! error.empty()) + try { - // If we're a subclass of LLEventDispatcher, e.g. LLEventAPI, report that. - error = stringize(LLError::Log::classname(this), "(", mDesc, "): ", error); - LL_WARNS("LLEventDispatcher") << error << LL_ENDL; + try_call(mKey, event[mKey], event); + return true; + } + catch (const DispatchMissing&) + { + return false; } - return error; } -// This internal method returns empty string if the call succeeded, else -// non-empty error message. -std::string LLEventDispatcher::try_call(const std::string& key, const LLSD& name, - const LLSD& event) const +LLSD LLEventDispatcher::try_call(const std::string& key, const std::string& name, + const LLSD& event) const { - if (name.isUndefined()) + if (name.empty()) { if (key.empty()) { - return "attempting to call with no name"; + callFail<DispatchError>("attempting to call with no name"); } else { - return stringize("no ", key); - } - } - else if (name.isArray()) - { - return stringize(key, " array dispatch ", name, " not yet implemented"); - } - else if (name.isMap()) - { - return stringize(key, " map dispatch ", name, " not yet implemented"); - } - else if (! name.isString()) - { - return stringize(key, " bad type ", LLSD::typeString(name.type()), ' ', name, - " -- function names are String"); - } - else // name is an LLSD::String - { - auto success{ try_call_one(key, name, event) }; - // pretend to unpack - std::string& error{ success.first }; - LLSD& result{ success.second }; - // did try_call_one() report an error? - if (! error.empty()) - { - // if we have a reply key, respond to invoker - reply(llsd::map("error", error), event); - // now tell caller - return error; - } - // try_call_one() succeeded in calling the target function -- - // should we reply to invoker? - if (result.isUndefined()) - { - // We would get result.isUndefined() if the target function has - // void return. In any case, even if the target function returns - // LLSD, isUndefined() means "don't bother sending response." - return {}; - } - // result.isDefined(): the target function returned something. - // Respond to invoker if we have a "reply" key. - if (! result.isMap()) - { - // wrap result in a map to play well with sendReply() - result = llsd::map("data", result); + callFail<DispatchError>("no ", key); } - reply(result, event); - return {}; } -} -std::pair<std::string, LLSD> -LLEventDispatcher::try_call_one(const std::string& key, const std::string& name, - const LLSD& event) const -{ DispatchMap::const_iterator found = mDispatch.find(name); if (found == mDispatch.end()) { + // Here we were passed a valid name, but there's no registered + // callable with that name. This is the one case in which we throw + // DispatchMissing instead of the generic DispatchError. + // Distinguish the public method by which our caller reached here: + // key.empty() means the name was passed explicitly, non-empty means + // we extracted the name from the incoming event using that key. if (key.empty()) { - return { stringize("'", name, "' not found"), {} }; + callFail<DispatchMissing>(std::quoted(name), " not found"); } else { - return { stringize("bad ", key, " value '", name, "'"), {} }; + callFail<DispatchMissing>("bad ", key, " value ", std::quoted(name)); } } - try - { - // Found the name, so it's plausible to even attempt the call. - return { {}, found->second->call(stringize("calling '", name, "'"), event) }; - } - catch (const DispatchError& err) - { - // trouble preparing arguments - return { err.what(), {} }; - } - catch (const LL::apply_error& err) - { - // could also hit runtime errors with LL::apply() - return { err.what(), {} }; - } + // Found the name, so it's plausible to even attempt the call. + return found->second->call(stringize(*this, " calling ", std::quoted(name)), + event, (! key.empty()), mArgskey); +} + +template <typename EXCEPTION, typename... ARGS> +//static +void LLEventDispatcher::sCallFail(ARGS&&... args) +{ + auto error = stringize(std::forward<ARGS>(args)...); + LL_WARNS("LLEventDispatcher") << error << LL_ENDL; + LLTHROW(EXCEPTION(error)); +} + +template <typename EXCEPTION, typename... ARGS> +void LLEventDispatcher::callFail(ARGS&&... args) const +{ + // Describe this instance in addition to the error itself. + sCallFail<EXCEPTION>(*this, ": ", std::forward<ARGS>(args)...); } LLSD LLEventDispatcher::getMetadata(const std::string& name) const @@ -729,27 +727,69 @@ LLSD LLEventDispatcher::getMetadata(const std::string& name) const return found->second->addMetadata(meta); } +std::ostream& operator<<(std::ostream& out, const LLEventDispatcher& self) +{ + // If we're a subclass of LLEventDispatcher, e.g. LLEventAPI, report that. + return out << LLError::Log::classname(self) << '(' << self.mDesc << ')'; +} + /***************************************************************************** * LLDispatchListener *****************************************************************************/ -LLDispatchListener::LLDispatchListener(const std::string& pumpname, const std::string& key): - LLEventDispatcher(pumpname, key), - // Do NOT tweak the passed pumpname. In practice, when someone - // instantiates a subclass of our LLEventAPI subclass, they intend to - // claim that LLEventPump name in the global LLEventPumps namespace. It - // would be mysterious and distressing if we allowed name tweaking, and - // someone else claimed pumpname first for a completely unrelated - // LLEventPump. Posted events would never reach our subclass listener - // because we would have silently changed its name; meanwhile listeners - // (if any) on that other LLEventPump would be confused by the events - // intended for our subclass. - LLEventStream(pumpname, false), - mBoundListener(listen("self", [this](const LLSD& event){ return process(event); })) +/*==========================================================================*| + 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 +|*==========================================================================*/ +std::string LLDispatchListener::mReplyKey{ "reply" }; + +bool LLDispatchListener::process(const LLSD& event) const { + LLSD result; + try + { + result = (*this)(event); + } + catch (const DispatchError& err) + { + // If the incoming event contains a "reply" key, we'll respond to the + // invoker with an error message (below). But if not -- silently + // ignoring an invocation request would be confusing at best. Escalate. + if (! event.has(mReplyKey)) + { + throw; + } + + // reply with a map containing an "error" key explaining the problem + reply(llsd::map("error", err.what()), event); + return false; + } + + // We seem to have gotten a valid result. But we don't know whether the + // registered callable is void or non-void. If it's void, + // LLEventDispatcher will return isUndefined(). Otherwise, try to send it + // back to our invoker. + if (result.isDefined()) + { + if (! result.isMap()) + { + // wrap the result in a map as the "data" key + result = llsd::map("data", result); + } + reply(result, event); + } + return false; } -bool LLDispatchListener::process(const LLSD& event) +void LLDispatchListener::reply(const LLSD& reply, const LLSD& request) const { - (*this)(event); - return false; + // Call sendReply() unconditionally: sendReply() itself tests whether the + // specified reply key is present in the incoming request, and does + // nothing if there's no such key. + sendReply(reply, request, mReplyKey); } |