diff options
Diffstat (limited to 'indra/llcommon/lleventdispatcher.cpp')
| -rw-r--r-- | indra/llcommon/lleventdispatcher.cpp | 535 |
1 files changed, 505 insertions, 30 deletions
diff --git a/indra/llcommon/lleventdispatcher.cpp b/indra/llcommon/lleventdispatcher.cpp index d6e820d793..2ab006a173 100644 --- a/indra/llcommon/lleventdispatcher.cpp +++ b/indra/llcommon/lleventdispatcher.cpp @@ -41,6 +41,326 @@ #include "llevents.h" #include "llerror.h" #include "llsdutil.h" +#include "stringize.h" +#include <memory> // std::auto_ptr + +/***************************************************************************** +* LLSDArgsSource +*****************************************************************************/ +/** + * Store an LLSD array, producing its elements one at a time. Die with LL_ERRS + * if the consumer requests more elements than the array contains. + */ +class LL_COMMON_API LLSDArgsSource +{ +public: + LLSDArgsSource(const std::string function, const LLSD& args); + ~LLSDArgsSource(); + + LLSD next(); + + void done() const; + +private: + std::string _function; + LLSD _args; + LLSD::Integer _index; +}; + +LLSDArgsSource::LLSDArgsSource(const std::string function, const LLSD& args): + _function(function), + _args(args), + _index(0) +{ + if (! (_args.isUndefined() || _args.isArray())) + { + LL_ERRS("LLSDArgsSource") << _function << " needs an args array instead of " + << _args << LL_ENDL; + } +} + +LLSDArgsSource::~LLSDArgsSource() +{ + done(); +} + +LLSD LLSDArgsSource::next() +{ + if (_index >= _args.size()) + { + LL_ERRS("LLSDArgsSource") << _function << " requires more arguments than the " + << _args.size() << " provided: " << _args << LL_ENDL; + } + return _args[_index++]; +} + +void LLSDArgsSource::done() const +{ + if (_index < _args.size()) + { + LL_WARNS("LLSDArgsSource") << _function << " only consumed " << _index + << " of the " << _args.size() << " arguments provided: " + << _args << LL_ENDL; + } +} + +/***************************************************************************** +* LLSDArgsMapper +*****************************************************************************/ +/** + * From a formal parameters description and a map of arguments, construct an + * arguments array. + * + * That is, given: + * - an LLSD array of length n containing parameter-name strings, + * corresponding to the arguments of a function of interest + * - an LLSD collection specifying default parameter values, either: + * - an LLSD array of length m <= n, matching the rightmost m params, or + * - an LLSD map explicitly stating default name=value pairs + * - an LLSD map of parameter names and actual values for a particular + * function call + * construct an LLSD array of actual argument values for this function call. + * + * The parameter-names array and the defaults collection describe the function + * being called. The map might vary with every call, providing argument values + * for the described parameters. + * + * The array of parameter names must match the number of parameters expected + * by the function of interest. + * + * If you pass a map of default parameter values, it provides default values + * as you might expect. It is an error to specify a default value for a name + * not listed in the parameters array. + * + * If you pass an array of default parameter values, it is mapped to the + * rightmost m of the n parameter names. It is an error if the default-values + * array is longer than the parameter-names array. Consider the following + * parameter names: ["a", "b", "c", "d"]. + * + * - An empty array of default values (or an isUndefined() value) asserts that + * every one of the above parameter names is required. + * - An array of four default values [1, 2, 3, 4] asserts that every one of + * the above parameters is optional. If the current parameter map is empty, + * they will be passed to the function as [1, 2, 3, 4]. + * - An array of two default values [11, 12] asserts that parameters "a" and + * "b" are required, while "c" and "d" are optional, having default values + * "c"=11 and "d"=12. + * + * The arguments array is constructed as follows: + * + * - Arguments-map keys not found in the parameter-names array are ignored. + * - Entries from the map provide values for an improper subset of the + * parameters named in the parameter-names array. This results in a + * tentative values array with "holes." (size of map) + (number of holes) = + * (size of names array) + * - Holes are filled with the default values. + * - Any remaining holes constitute an error. + */ +class LL_COMMON_API LLSDArgsMapper +{ +public: + /// Accept description of function: function name, param names, param + /// default values + LLSDArgsMapper(const std::string& function, const LLSD& names, const LLSD& defaults); + + /// Given arguments map, return LLSD::Array of parameter values, or LL_ERRS. + LLSD map(const LLSD& argsmap) const; + +private: + static std::string formatlist(const LLSD&); + + // The function-name string is purely descriptive. We want error messages + // to be able to indicate which function's LLSDArgsMapper has the problem. + std::string _function; + // Store the names array pretty much as given. + LLSD _names; + // Though we're handed an array of name strings, it's more useful to us to + // store it as a map from name string to position index. Of course that's + // easy to generate from the incoming names array, but why do it more than + // once? + typedef std::map<LLSD::String, LLSD::Integer> IndexMap; + IndexMap _indexes; + // Generated array of default values, aligned with the array of param names. + LLSD _defaults; + // Indicate whether we have a default value for each param. + typedef std::vector<char> FilledVector; + FilledVector _has_dft; +}; + +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())) + { + LL_ERRS("LLSDArgsMapper") << function << " names must be an array, not " << names << LL_ENDL; + } + LLSD::Integer nparams(_names.size()); + // From _names generate _indexes. + for (LLSD::Integer ni = 0, nend = _names.size(); ni < nend; ++ni) + { + _indexes[_names[ni]] = ni; + } + + // Presize _defaults() array so we don't have to resize it more than once. + // All entries are initialized to LLSD(); but since _has_dft is still all + // 0, they're all "holes" for now. + if (nparams) + { + _defaults[nparams - 1] = LLSD(); + } + + if (defaults.isUndefined() || defaults.isArray()) + { + LLSD::Integer ndefaults = defaults.size(); + // defaults is a (possibly empty) array. Right-align it with names. + if (ndefaults > nparams) + { + LL_ERRS("LLSDArgsMapper") << function << " names array " << names + << " shorter than defaults array " << defaults << LL_ENDL; + } + + // Offset by which we slide defaults array right to right-align with + // _names array + LLSD::Integer offset = nparams - ndefaults; + // Fill rightmost _defaults entries from defaults, and mark them as + // filled + for (LLSD::Integer i = 0, iend = ndefaults; i < iend; ++i) + { + _defaults[i + offset] = defaults[i]; + _has_dft[i + offset] = 1; + } + } + else if (defaults.isMap()) + { + // defaults is a map. Use it to populate the _defaults array. + LLSD bogus; + for (LLSD::map_const_iterator mi(defaults.beginMap()), mend(defaults.endMap()); + mi != mend; ++mi) + { + IndexMap::const_iterator ixit(_indexes.find(mi->first)); + if (ixit == _indexes.end()) + { + bogus.append(mi->first); + continue; + } + + LLSD::Integer pos = ixit->second; + // Store default value at that position in the _defaults array. + _defaults[pos] = mi->second; + // Don't forget to record the fact that we've filled this + // position. + _has_dft[pos] = 1; + } + if (bogus.size()) + { + LL_ERRS("LLSDArgsMapper") << function << " defaults specified for nonexistent params " + << formatlist(bogus) << LL_ENDL; + } + } + else + { + LL_ERRS("LLSDArgsMapper") << function << " defaults must be a map or an array, not " + << defaults << LL_ENDL; + } +} + +LLSD LLSDArgsMapper::map(const LLSD& argsmap) const +{ + if (! (argsmap.isUndefined() || argsmap.isMap())) + { + LL_ERRS("LLSDArgsMapper") << _function << " map() needs a map, not " << argsmap << LL_ENDL; + } + // 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 + // new operation. Just make it as big as we need before we start + // stuffing values into it. + LLSD args(LLSD::emptyArray()); + if (_defaults.size() == 0) + { + // If this function requires no arguments, fast exit. (Don't try to + // assign to args[-1].) + return args; + } + args[_defaults.size() - 1] = LLSD(); + + // Get a vector of chars to indicate holes. It's tempting to just scan + // for LLSD::isUndefined() values after filling the args array from + // the map, but it's plausible for caller to explicitly pass + // isUndefined() as the value of some parameter name. That's legal + // since isUndefined() has well-defined conversions (default value) + // for LLSD data types. So use a whole separate array for detecting + // holes. (Avoid std::vector<bool> which is known to be odd -- can we + // iterate?) + FilledVector filled(args.size()); + // Walk the map. + for (LLSD::map_const_iterator mi(argsmap.beginMap()), mend(argsmap.endMap()); + mi != mend; ++mi) + { + // mi->first is a parameter-name string, with mi->second its + // value. Look up the name's position index in _indexes. + IndexMap::const_iterator ixit(_indexes.find(mi->first)); + if (ixit == _indexes.end()) + { + // Allow for a map containing more params than were passed in + // our names array. Caller typically receives a map containing + // the function name, cruft such as reqid, etc. Ignore keys + // not defined in _indexes. + LL_DEBUGS("LLSDArgsMapper") << _function << " ignoring " + << mi->first << "=" << mi->second << LL_ENDL; + continue; + } + LLSD::Integer pos = ixit->second; + // Store the value at that position in the args array. + args[pos] = mi->second; + // Don't forget to record the fact that we've filled this + // position. + filled[pos] = 1; + } + // Fill any remaining holes from _defaults. + LLSD unfilled(LLSD::emptyArray()); + for (LLSD::Integer i = 0, iend = args.size(); i < iend; ++i) + { + if (! filled[i]) + { + // If there's no default value for this parameter, that's an + // error. + if (! _has_dft[i]) + { + unfilled.append(_names[i]); + } + else + { + args[i] = _defaults[i]; + } + } + } + // If any required args -- args without defaults -- were left unfilled + // by argsmap, that's a problem. + if (unfilled.size()) + { + LL_ERRS("LLSDArgsMapper") << _function << " missing required arguments " + << formatlist(unfilled) << " from " << argsmap << LL_ENDL; + } + + // done + return args; +} + +std::string LLSDArgsMapper::formatlist(const LLSD& list) +{ + std::ostringstream out; + const char* delim = ""; + for (LLSD::array_const_iterator li(list.beginArray()), lend(list.endArray()); + li != lend; ++li) + { + out << delim << li->asString(); + delim = ", "; + } + return out.str(); +} LLEventDispatcher::LLEventDispatcher(const std::string& desc, const std::string& key): mDesc(desc), @@ -52,12 +372,178 @@ LLEventDispatcher::~LLEventDispatcher() { } +/** + * DispatchEntry subclass used for callables accepting(const LLSD&) + */ +struct LLEventDispatcher::LLSDDispatchEntry: public LLEventDispatcher::DispatchEntry +{ + LLSDDispatchEntry(const std::string& desc, const Callable& func, const LLSD& required): + DispatchEntry(desc), + mFunc(func), + mRequired(required) + {} + + Callable mFunc; + LLSD mRequired; + + virtual void call(const std::string& desc, const LLSD& event) const + { + // Validate the syntax of the event itself. + std::string mismatch(llsd_matches(mRequired, event)); + if (! mismatch.empty()) + { + LL_ERRS("LLEventDispatcher") << desc << ": bad request: " << mismatch << LL_ENDL; + } + // Event syntax looks good, go for it! + mFunc(event); + } + + virtual LLSD addMetadata(LLSD meta) const + { + meta["required"] = mRequired; + return meta; + } +}; + +/** + * DispatchEntry subclass for passing LLSD to functions accepting + * arbitrary argument types (convertible via LLSDParam) + */ +struct LLEventDispatcher::ParamsDispatchEntry: public LLEventDispatcher::DispatchEntry +{ + ParamsDispatchEntry(const std::string& desc, const invoker_function& func): + DispatchEntry(desc), + mInvoker(func) + {} + + invoker_function mInvoker; + + virtual void call(const std::string& desc, const LLSD& event) const + { + LLSDArgsSource src(desc, event); + mInvoker(boost::bind(&LLSDArgsSource::next, boost::ref(src))); + } +}; + +/** + * DispatchEntry subclass for dispatching LLSD::Array to functions accepting + * arbitrary argument types (convertible via LLSDParam) + */ +struct LLEventDispatcher::ArrayParamsDispatchEntry: public LLEventDispatcher::ParamsDispatchEntry +{ + ArrayParamsDispatchEntry(const std::string& desc, const invoker_function& func, + LLSD::Integer arity): + ParamsDispatchEntry(desc, func), + mArity(arity) + {} + + LLSD::Integer mArity; + + virtual LLSD addMetadata(LLSD meta) const + { + LLSD array(LLSD::emptyArray()); + // Resize to number of arguments required + array[mArity - 1] = LLSD(); + llassert_always(array.size() == mArity); + meta["required"] = array; + return meta; + } +}; + +/** + * DispatchEntry subclass for dispatching LLSD::Map to functions accepting + * arbitrary argument types (convertible via LLSDParam) + */ +struct LLEventDispatcher::MapParamsDispatchEntry: public LLEventDispatcher::ParamsDispatchEntry +{ + MapParamsDispatchEntry(const std::string& name, const std::string& desc, + const invoker_function& func, + const LLSD& params, const LLSD& defaults): + ParamsDispatchEntry(desc, func), + mMapper(name, params, defaults), + mRequired(LLSD::emptyMap()) + { + // Build the set of all param keys, then delete the ones that are + // optional. What's left are the ones that are required. + for (LLSD::array_const_iterator pi(params.beginArray()), pend(params.endArray()); + pi != pend; ++pi) + { + mRequired[pi->asString()] = LLSD(); + } + + if (defaults.isArray() || defaults.isUndefined()) + { + // Right-align the params and defaults arrays. + LLSD::Integer offset = params.size() - defaults.size(); + // Now the name of every defaults[i] is at params[i + offset]. + for (LLSD::Integer i(0), iend(defaults.size()); i < iend; ++i) + { + // Erase this optional param from mRequired. + mRequired.erase(params[i + offset].asString()); + // Instead, make an entry in mOptional with the default + // param's name and value. + mOptional[params[i + offset].asString()] = defaults[i]; + } + } + else if (defaults.isMap()) + { + // if defaults is already a map, then it's already in the form we + // intend to deliver in metadata + mOptional = defaults; + // Just delete from mRequired every key appearing in mOptional. + for (LLSD::map_const_iterator mi(mOptional.beginMap()), mend(mOptional.endMap()); + mi != mend; ++mi) + { + mRequired.erase(mi->first); + } + } + } + + LLSDArgsMapper mMapper; + LLSD mRequired; + LLSD mOptional; + + virtual void call(const std::string& desc, const LLSD& event) const + { + // Just convert from LLSD::Map to LLSD::Array using mMapper, then pass + // to base-class call() method. + ParamsDispatchEntry::call(desc, mMapper.map(event)); + } + + virtual LLSD addMetadata(LLSD meta) const + { + meta["required"] = mRequired; + meta["optional"] = mOptional; + return meta; + } +}; + +void LLEventDispatcher::addArrayParamsDispatchEntry(const std::string& name, + const std::string& desc, + const invoker_function& invoker, + LLSD::Integer arity) +{ + // Peculiar to me that boost::ptr_map() accepts std::auto_ptr but not dumb ptr + mDispatch.insert(name, std::auto_ptr<DispatchEntry>( + new ArrayParamsDispatchEntry(desc, invoker, arity))); +} + +void LLEventDispatcher::addMapParamsDispatchEntry(const std::string& name, + const std::string& desc, + const invoker_function& invoker, + const LLSD& params, + const LLSD& defaults) +{ + mDispatch.insert(name, std::auto_ptr<DispatchEntry>( + new MapParamsDispatchEntry(name, desc, invoker, params, defaults))); +} + /// Register a callable by name void LLEventDispatcher::add(const std::string& name, const std::string& desc, const Callable& callable, const LLSD& required) { - mDispatch.insert(DispatchMap::value_type(name, - DispatchMap::mapped_type(callable, desc, required))); + mDispatch.insert(name, std::auto_ptr<DispatchEntry>( + new LLSDDispatchEntry(desc, callable, required))); } void LLEventDispatcher::addFail(const std::string& name, const std::string& classname) const @@ -83,7 +569,7 @@ bool LLEventDispatcher::remove(const std::string& name) /// such callable exists, die with LL_ERRS. void LLEventDispatcher::operator()(const std::string& name, const LLSD& event) const { - if (! attemptCall(name, event)) + if (! try_call(name, event)) { LL_ERRS("LLEventDispatcher") << "LLEventDispatcher(" << mDesc << "): '" << name << "' not found" << LL_ENDL; @@ -98,44 +584,29 @@ void LLEventDispatcher::operator()(const LLSD& event) const // This could/should be implemented in terms of the two-arg overload. // However -- we can produce a more informative error message. std::string name(event[mKey]); - if (! attemptCall(name, event)) + if (! try_call(name, event)) { LL_ERRS("LLEventDispatcher") << "LLEventDispatcher(" << mDesc << "): bad " << mKey << " value '" << name << "'" << LL_ENDL; } } -bool LLEventDispatcher::attemptCall(const std::string& name, const LLSD& event) const +bool LLEventDispatcher::try_call(const LLSD& event) const { - DispatchMap::const_iterator found = mDispatch.find(name); - if (found == mDispatch.end()) - { - // The reason we only return false, leaving it up to our caller to die - // with LL_ERRS, is that different callers have different amounts of - // available information. - return false; - } - // Found the name, so it's plausible to even attempt the call. But first, - // validate the syntax of the event itself. - std::string mismatch(llsd_matches(found->second.mRequired, event)); - if (! mismatch.empty()) - { - LL_ERRS("LLEventDispatcher") << "LLEventDispatcher(" << mDesc << ") calling '" << name - << "': bad request: " << mismatch << LL_ENDL; - } - // Event syntax looks good, go for it! - (found->second.mFunc)(event); - return true; // tell caller we were able to call + return try_call(event[mKey], event); } -LLEventDispatcher::Callable LLEventDispatcher::get(const std::string& name) const +bool LLEventDispatcher::try_call(const std::string& name, const LLSD& event) const { DispatchMap::const_iterator found = mDispatch.find(name); if (found == mDispatch.end()) { - return Callable(); + return false; } - return found->second.mFunc; + // Found the name, so it's plausible to even attempt the call. + found->second->call(STRINGIZE("LLEventDispatcher(" << mDesc << ") calling '" << name << "'"), + event); + return true; // tell caller we were able to call } LLSD LLEventDispatcher::getMetadata(const std::string& name) const @@ -147,9 +618,8 @@ LLSD LLEventDispatcher::getMetadata(const std::string& name) const } LLSD meta; meta["name"] = name; - meta["desc"] = found->second.mDesc; - meta["required"] = found->second.mRequired; - return meta; + meta["desc"] = found->second->mDesc; + return found->second->addMetadata(meta); } LLDispatchListener::LLDispatchListener(const std::string& pumpname, const std::string& key): @@ -164,3 +634,8 @@ bool LLDispatchListener::process(const LLSD& event) (*this)(event); return false; } + +LLEventDispatcher::DispatchEntry::DispatchEntry(const std::string& desc): + mDesc(desc) +{} + |