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arangodb/arangod/Aql/Function.cpp

145 lines
4.3 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////
#include "Aql/Function.h"
#include "Basics/Exceptions.h"
using namespace arangodb::aql;
/// @brief create the function
Function::Function(std::string const& externalName,
std::string const& internalName,
std::string const& arguments, bool isCacheable,
bool isDeterministic, bool canThrow, bool canRunOnDBServer,
bool canPassArgumentsByReference,
FunctionImplementation implementation,
ExecutionCondition condition)
: internalName(internalName),
externalName(externalName),
arguments(arguments),
isCacheable(isCacheable),
isDeterministic(isDeterministic),
canThrow(canThrow),
canRunOnDBServer(canRunOnDBServer),
canPassArgumentsByReference(canPassArgumentsByReference),
implementation(implementation),
condition(condition),
conversions() {
initializeArguments();
// condition must only be set if we also have an implementation
TRI_ASSERT(implementation != nullptr ||
(implementation == nullptr && condition == nullptr));
}
/// @brief destroy the function
Function::~Function() {}
/// @brief parse the argument list and set the minimum and maximum number of
/// arguments
void Function::initializeArguments() {
minRequiredArguments = 0;
maxRequiredArguments = 0;
size_t position = 0;
// setup some parsing state
bool inOptional = false;
bool foundArg = false;
char const* p = arguments.c_str();
while (true) {
char const c = *p++;
switch (c) {
case '\0':
// end of argument list
if (foundArg) {
if (!inOptional) {
++minRequiredArguments;
}
++maxRequiredArguments;
}
return;
case '|':
// beginning of optional arguments
++position;
TRI_ASSERT(!inOptional);
if (foundArg) {
++minRequiredArguments;
++maxRequiredArguments;
}
inOptional = true;
foundArg = false;
break;
case ',':
// next argument
++position;
TRI_ASSERT(foundArg);
if (!inOptional) {
++minRequiredArguments;
}
++maxRequiredArguments;
foundArg = false;
break;
case '+':
// repeated optional argument
TRI_ASSERT(inOptional);
maxRequiredArguments = MaxArguments;
return;
case 'h':
// we found a collection parameter
// set the conversion info for the position
if (conversions.size() <= position) {
// we don't yet have another parameter at this position
conversions.emplace_back(CONVERSION_REQUIRED);
} else if (conversions[position] == CONVERSION_NONE) {
// we already had a parameter at this position
conversions[position] = CONVERSION_OPTIONAL;
}
foundArg = true;
break;
default:
// we found any other parameter
// set the conversion info for the position
if (conversions.size() <= position) {
// we don't yet have another parameter at this position
conversions.emplace_back(CONVERSION_NONE);
} else if (conversions[position] == CONVERSION_REQUIRED) {
// we already had a parameter at this position
conversions[position] = CONVERSION_OPTIONAL;
}
foundArg = true;
break;
}
}
}