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Diffstat (limited to 'indra/llcommon/llsdutil.cpp')
| -rw-r--r-- | indra/llcommon/llsdutil.cpp | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/indra/llcommon/llsdutil.cpp b/indra/llcommon/llsdutil.cpp index 0202a033c3..c8d8030e87 100644 --- a/indra/llcommon/llsdutil.cpp +++ b/indra/llcommon/llsdutil.cpp @@ -46,6 +46,11 @@ #endif #include "llsdserialize.h" +#include "stringize.h" + +#include <map> +#include <set> +#include <boost/range.hpp> // U32 LLSD ll_sd_from_U32(const U32 val) @@ -313,3 +318,353 @@ BOOL compare_llsd_with_template( return TRUE; } + +/***************************************************************************** +* Helpers for llsd_matches() +*****************************************************************************/ +// raw data used for LLSD::Type lookup +struct Data +{ + LLSD::Type type; + const char* name; +} typedata[] = +{ +#define def(type) { LLSD::type, #type + 4 } + def(TypeUndefined), + def(TypeBoolean), + def(TypeInteger), + def(TypeReal), + def(TypeString), + def(TypeUUID), + def(TypeDate), + def(TypeURI), + def(TypeBinary), + def(TypeMap), + def(TypeArray) +#undef def +}; + +// LLSD::Type lookup class into which we load the above static data +class TypeLookup +{ + typedef std::map<LLSD::Type, std::string> MapType; + +public: + TypeLookup() + { + for (const Data *di(boost::begin(typedata)), *dend(boost::end(typedata)); di != dend; ++di) + { + mMap[di->type] = di->name; + } + } + + std::string lookup(LLSD::Type type) const + { + MapType::const_iterator found = mMap.find(type); + if (found != mMap.end()) + { + return found->second; + } + return STRINGIZE("<unknown LLSD type " << type << ">"); + } + +private: + MapType mMap; +}; + +// static instance of the lookup class +static const TypeLookup sTypes; + +// describe a mismatch; phrasing may want tweaking +const std::string op(" required instead of "); + +// llsd_matches() wants to identify specifically where in a complex prototype +// structure the mismatch occurred. This entails passing a prefix string, +// empty for the top-level call. If the prototype contains an array of maps, +// and the mismatch occurs in the second map in a key 'foo', we want to +// decorate the returned string with: "[1]['foo']: etc." On the other hand, we +// want to omit the entire prefix -- including colon -- if the mismatch is at +// top level. This helper accepts the (possibly empty) recursively-accumulated +// prefix string, returning either empty or the original string with colon +// appended. +static std::string colon(const std::string& pfx) +{ + if (pfx.empty()) + return pfx; + return pfx + ": "; +} + +// param type for match_types +typedef std::vector<LLSD::Type> TypeVector; + +// The scalar cases in llsd_matches() use this helper. In most cases, we can +// accept not only the exact type specified in the prototype, but also other +// types convertible to the expected type. That implies looping over an array +// of such types. If the actual type doesn't match any of them, we want to +// provide a list of acceptable conversions as well as the exact type, e.g.: +// "Integer (or Boolean, Real, String) required instead of UUID". Both the +// implementation and the calling logic are simplified by separating out the +// expected type from the convertible types. +static std::string match_types(LLSD::Type expect, // prototype.type() + const TypeVector& accept, // types convertible to that type + LLSD::Type actual, // type we're checking + const std::string& pfx) // as for llsd_matches +{ + // Trivial case: if the actual type is exactly what we expect, we're good. + if (actual == expect) + return ""; + + // For the rest of the logic, build up a suitable error string as we go so + // we only have to make a single pass over the list of acceptable types. + // If we detect success along the way, we'll simply discard the partial + // error string. + std::ostringstream out; + out << colon(pfx) << sTypes.lookup(expect); + + // If there are any convertible types, append that list. + if (! accept.empty()) + { + out << " ("; + const char* sep = "or "; + for (TypeVector::const_iterator ai(accept.begin()), aend(accept.end()); + ai != aend; ++ai, sep = ", ") + { + // Don't forget to return success if we match any of those types... + if (actual == *ai) + return ""; + out << sep << sTypes.lookup(*ai); + } + out << ')'; + } + // If we got this far, it's because 'actual' was not one of the acceptable + // types, so we must return an error. 'out' already contains colon(pfx) + // and the formatted list of acceptable types, so just append the mismatch + // phrase and the actual type. + out << op << sTypes.lookup(actual); + return out.str(); +} + +// see docstring in .h file +std::string llsd_matches(const LLSD& prototype, const LLSD& data, const std::string& pfx) +{ + // An undefined prototype means that any data is valid. + // An undefined slot in an array or map prototype means that any data + // may fill that slot. + if (prototype.isUndefined()) + return ""; + // A prototype array must match a data array with at least as many + // entries. Moreover, every prototype entry must match the + // corresponding data entry. + if (prototype.isArray()) + { + if (! data.isArray()) + { + return STRINGIZE(colon(pfx) << "Array" << op << sTypes.lookup(data.type())); + } + if (data.size() < prototype.size()) + { + return STRINGIZE(colon(pfx) << "Array size " << prototype.size() << op + << "Array size " << data.size()); + } + for (LLSD::Integer i = 0; i < prototype.size(); ++i) + { + std::string match(llsd_matches(prototype[i], data[i], STRINGIZE('[' << i << ']'))); + if (! match.empty()) + { + return match; + } + } + return ""; + } + // A prototype map must match a data map. Every key in the prototype + // must have a corresponding key in the data map; every value in the + // prototype must match the corresponding key's value in the data. + if (prototype.isMap()) + { + if (! data.isMap()) + { + return STRINGIZE(colon(pfx) << "Map" << op << sTypes.lookup(data.type())); + } + // If there are a number of keys missing from the data, it would be + // frustrating to a coder to discover them one at a time, with a big + // build each time. Enumerate all missing keys. + std::ostringstream out; + out << colon(pfx); + const char* init = "Map missing keys: "; + const char* sep = init; + for (LLSD::map_const_iterator mi = prototype.beginMap(); mi != prototype.endMap(); ++mi) + { + if (! data.has(mi->first)) + { + out << sep << mi->first; + sep = ", "; + } + } + // So... are we missing any keys? + if (sep != init) + { + return out.str(); + } + // Good, the data block contains all the keys required by the + // prototype. Now match the prototype entries. + for (LLSD::map_const_iterator mi2 = prototype.beginMap(); mi2 != prototype.endMap(); ++mi2) + { + std::string match(llsd_matches(mi2->second, data[mi2->first], + STRINGIZE("['" << mi2->first << "']"))); + if (! match.empty()) + { + return match; + } + } + return ""; + } + // A String prototype can match String, Boolean, Integer, Real, UUID, + // Date and URI, because any of these can be converted to String. + if (prototype.isString()) + { + static LLSD::Type accept[] = + { + LLSD::TypeBoolean, + LLSD::TypeInteger, + LLSD::TypeReal, + LLSD::TypeUUID, + LLSD::TypeDate, + LLSD::TypeURI + }; + return match_types(prototype.type(), + TypeVector(boost::begin(accept), boost::end(accept)), + data.type(), + pfx); + } + // Boolean, Integer, Real match each other or String. TBD: ensure that + // a String value is numeric. + if (prototype.isBoolean() || prototype.isInteger() || prototype.isReal()) + { + static LLSD::Type all[] = + { + LLSD::TypeBoolean, + LLSD::TypeInteger, + LLSD::TypeReal, + LLSD::TypeString + }; + // Funny business: shuffle the set of acceptable types to include all + // but the prototype's type. Get the acceptable types in a set. + std::set<LLSD::Type> rest(boost::begin(all), boost::end(all)); + // Remove the prototype's type because we pass that separately. + rest.erase(prototype.type()); + return match_types(prototype.type(), + TypeVector(rest.begin(), rest.end()), + data.type(), + pfx); + } + // UUID, Date and URI match themselves or String. + if (prototype.isUUID() || prototype.isDate() || prototype.isURI()) + { + static LLSD::Type accept[] = + { + LLSD::TypeString + }; + return match_types(prototype.type(), + TypeVector(boost::begin(accept), boost::end(accept)), + data.type(), + pfx); + } + // We don't yet know the conversion semantics associated with any new LLSD + // data type that might be added, so until we've been extended to handle + // them, assume it's strict: the new type matches only itself. (This is + // true of Binary, which is why we don't handle that case separately.) Too + // bad LLSD doesn't define isConvertible(Type to, Type from). + return match_types(prototype.type(), TypeVector(), data.type(), pfx); +} + +bool llsd_equals(const LLSD& lhs, const LLSD& rhs) +{ + // We're comparing strict equality of LLSD representation rather than + // performing any conversions. So if the types aren't equal, the LLSD + // values aren't equal. + if (lhs.type() != rhs.type()) + { + return false; + } + + // Here we know both types are equal. Now compare values. + switch (lhs.type()) + { + case LLSD::TypeUndefined: + // Both are TypeUndefined. There's nothing more to know. + return true; + +#define COMPARE_SCALAR(type) \ + case LLSD::Type##type: \ + /* LLSD::URI has operator!=() but not operator==() */ \ + /* rely on the optimizer for all others */ \ + return (! (lhs.as##type() != rhs.as##type())) + + COMPARE_SCALAR(Boolean); + COMPARE_SCALAR(Integer); + // The usual caveats about comparing floating-point numbers apply. This is + // only useful when we expect identical bit representation for a given + // Real value, e.g. for integer-valued Reals. + COMPARE_SCALAR(Real); + COMPARE_SCALAR(String); + COMPARE_SCALAR(UUID); + COMPARE_SCALAR(Date); + COMPARE_SCALAR(URI); + COMPARE_SCALAR(Binary); + +#undef COMPARE_SCALAR + + case LLSD::TypeArray: + { + LLSD::array_const_iterator + lai(lhs.beginArray()), laend(lhs.endArray()), + rai(rhs.beginArray()), raend(rhs.endArray()); + // Compare array elements, walking the two arrays in parallel. + for ( ; lai != laend && rai != raend; ++lai, ++rai) + { + // If any one array element is unequal, the arrays are unequal. + if (! llsd_equals(*lai, *rai)) + return false; + } + // Here we've reached the end of one or the other array. They're equal + // only if they're BOTH at end: that is, if they have equal length too. + return (lai == laend && rai == raend); + } + + case LLSD::TypeMap: + { + // Build a set of all rhs keys. + std::set<LLSD::String> rhskeys; + for (LLSD::map_const_iterator rmi(rhs.beginMap()), rmend(rhs.endMap()); + rmi != rmend; ++rmi) + { + rhskeys.insert(rmi->first); + } + // Now walk all the lhs keys. + for (LLSD::map_const_iterator lmi(lhs.beginMap()), lmend(lhs.endMap()); + lmi != lmend; ++lmi) + { + // Try to erase this lhs key from the set of rhs keys. If rhs has + // no such key, the maps are unequal. erase(key) returns count of + // items erased. + if (rhskeys.erase(lmi->first) != 1) + return false; + // Both maps have the current key. Compare values. + if (! llsd_equals(lmi->second, rhs[lmi->first])) + return false; + } + // We've now established that all the lhs keys have equal values in + // both maps. The maps are equal unless rhs contains a superset of + // those keys. + return rhskeys.empty(); + } + + default: + // We expect that every possible type() value is specifically handled + // above. Failing to extend this switch to support a new LLSD type is + // an error that must be brought to the coder's attention. + LL_ERRS("llsd_equals") << "llsd_equals(" << lhs << ", " << rhs << "): " + "unknown type " << lhs.type() << LL_ENDL; + return false; // pacify the compiler + } +} |