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arangodb/arangod/Aql/AstNode.h

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////////////////////////////////////////////////////////////////////////////////
/// 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
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_AQL_AST_NODE_H
#define ARANGOD_AQL_AST_NODE_H 1
#include "Basics/AttributeNameParser.h"
#include "Basics/Common.h"
#include "Basics/Exceptions.h"
#include "Basics/ScopeGuard.h"
#include <velocypack/Slice.h>
#include <velocypack/StringRef.h>
#include <iosfwd>
namespace arangodb {
namespace velocypack {
class Builder;
class Slice;
} // namespace velocypack
namespace basics {
class StringBuffer;
}
namespace aql {
class Ast;
struct Variable;
/// @brief type for node flags
typedef uint32_t AstNodeFlagsType;
/// @brief different flags for nodes
/// the flags are used to prevent repeated calculations of node properties
/// (e.g. is the node value constant, sorted etc.)
enum AstNodeFlagType : AstNodeFlagsType {
DETERMINED_SORTED = 0x0000001, // node is a list and its members are sorted asc.
DETERMINED_CONSTANT = 0x0000002, // node value is constant (i.e. not dynamic)
DETERMINED_SIMPLE = 0x0000004, // node value is simple (i.e. for use in a simple expression)
DETERMINED_NONDETERMINISTIC = 0x0000010, // node produces non-deterministic
// result (e.g. function call nodes)
DETERMINED_RUNONDBSERVER = 0x0000020, // node can run on the DB server in a cluster setup
DETERMINED_CHECKUNIQUENESS = 0x0000040, // object's keys must be checked for uniqueness
DETERMINED_V8 = 0x0000080, // node will use V8 internally
VALUE_SORTED = 0x0000100, // node is a list and its members are sorted asc.
VALUE_CONSTANT = 0x0000200, // node value is constant (i.e. not dynamic)
VALUE_SIMPLE = 0x0000400, // node value is simple (i.e. for use in a simple expression)
VALUE_NONDETERMINISTIC = 0x0001000, // node produces non-deterministic result
// (e.g. function call nodes)
VALUE_RUNONDBSERVER = 0x0002000, // node can run on the DB server in a cluster setup
VALUE_CHECKUNIQUENESS = 0x0004000, // object's keys must be checked for uniqueness
VALUE_V8 = 0x0008000, // node will use V8 internally
FLAG_KEEP_VARIABLENAME = 0x0010000, // node is a reference to a variable name, not the variable
// value (used in KEEP nodes)
FLAG_BIND_PARAMETER = 0x0020000, // node was created from a bind parameter
FLAG_FINALIZED = 0x0040000, // node has been finalized and should not be modified; only
// set and checked in maintainer mode
};
/// @brief enumeration of AST node value types
/// note: these types must be declared in asc. sort order
enum AstNodeValueType : uint8_t {
VALUE_TYPE_NULL = 0,
VALUE_TYPE_BOOL = 1,
VALUE_TYPE_INT = 2,
VALUE_TYPE_DOUBLE = 3,
VALUE_TYPE_STRING = 4
};
static_assert(VALUE_TYPE_NULL < VALUE_TYPE_BOOL,
"incorrect ast node value types");
static_assert(VALUE_TYPE_BOOL < VALUE_TYPE_INT,
"incorrect ast node value types");
static_assert(VALUE_TYPE_INT < VALUE_TYPE_DOUBLE,
"incorrect ast node value types");
static_assert(VALUE_TYPE_DOUBLE < VALUE_TYPE_STRING,
"incorrect ast node value types");
/// @brief AST node value
struct AstNodeValue {
union Value {
int64_t _int;
double _double;
bool _bool;
char const* _string;
void* _data;
// constructors for union values
explicit Value(int64_t value) : _int(value) {}
explicit Value(double value) : _double(value) {}
explicit Value(bool value) : _bool(value) {}
explicit Value(char const* value) : _string(value) {}
};
Value value;
uint32_t length; // only used for string values
AstNodeValueType type;
AstNodeValue() : value(int64_t(0)), length(0), type(VALUE_TYPE_NULL) {}
explicit AstNodeValue(int64_t value)
: value(value), length(0), type(VALUE_TYPE_INT) {}
explicit AstNodeValue(double value)
: value(value), length(0), type(VALUE_TYPE_DOUBLE) {}
explicit AstNodeValue(bool value)
: value(value), length(0), type(VALUE_TYPE_BOOL) {}
explicit AstNodeValue(char const* value, uint32_t length)
: value(value), length(length), type(VALUE_TYPE_STRING) {}
};
/// @brief enumeration of AST node types
enum AstNodeType : uint32_t {
NODE_TYPE_ROOT = 0,
NODE_TYPE_FOR = 1,
NODE_TYPE_LET = 2,
NODE_TYPE_FILTER = 3,
NODE_TYPE_RETURN = 4,
NODE_TYPE_REMOVE = 5,
NODE_TYPE_INSERT = 6,
NODE_TYPE_UPDATE = 7,
NODE_TYPE_REPLACE = 8,
NODE_TYPE_COLLECT = 9,
NODE_TYPE_SORT = 10,
NODE_TYPE_SORT_ELEMENT = 11,
NODE_TYPE_LIMIT = 12,
NODE_TYPE_VARIABLE = 13,
NODE_TYPE_ASSIGN = 14,
NODE_TYPE_OPERATOR_UNARY_PLUS = 15,
NODE_TYPE_OPERATOR_UNARY_MINUS = 16,
NODE_TYPE_OPERATOR_UNARY_NOT = 17,
NODE_TYPE_OPERATOR_BINARY_AND = 18,
NODE_TYPE_OPERATOR_BINARY_OR = 19,
NODE_TYPE_OPERATOR_BINARY_PLUS = 20,
NODE_TYPE_OPERATOR_BINARY_MINUS = 21,
NODE_TYPE_OPERATOR_BINARY_TIMES = 22,
NODE_TYPE_OPERATOR_BINARY_DIV = 23,
NODE_TYPE_OPERATOR_BINARY_MOD = 24,
NODE_TYPE_OPERATOR_BINARY_EQ = 25,
NODE_TYPE_OPERATOR_BINARY_NE = 26,
NODE_TYPE_OPERATOR_BINARY_LT = 27,
NODE_TYPE_OPERATOR_BINARY_LE = 28,
NODE_TYPE_OPERATOR_BINARY_GT = 29,
NODE_TYPE_OPERATOR_BINARY_GE = 30,
NODE_TYPE_OPERATOR_BINARY_IN = 31,
NODE_TYPE_OPERATOR_BINARY_NIN = 32,
NODE_TYPE_OPERATOR_TERNARY = 33,
NODE_TYPE_SUBQUERY = 34,
NODE_TYPE_ATTRIBUTE_ACCESS = 35,
NODE_TYPE_BOUND_ATTRIBUTE_ACCESS = 36,
NODE_TYPE_INDEXED_ACCESS = 37,
NODE_TYPE_EXPANSION = 38,
NODE_TYPE_ITERATOR = 39,
NODE_TYPE_VALUE = 40,
NODE_TYPE_ARRAY = 41,
NODE_TYPE_OBJECT = 42,
NODE_TYPE_OBJECT_ELEMENT = 43,
NODE_TYPE_COLLECTION = 44,
NODE_TYPE_REFERENCE = 45,
NODE_TYPE_PARAMETER = 46,
NODE_TYPE_FCALL = 47,
NODE_TYPE_FCALL_USER = 48,
NODE_TYPE_RANGE = 49,
NODE_TYPE_NOP = 50,
NODE_TYPE_COLLECT_COUNT = 51,
NODE_TYPE_CALCULATED_OBJECT_ELEMENT = 53,
NODE_TYPE_UPSERT = 54,
NODE_TYPE_EXAMPLE = 55,
NODE_TYPE_PASSTHRU = 56,
NODE_TYPE_ARRAY_LIMIT = 57,
NODE_TYPE_DISTINCT = 58,
NODE_TYPE_TRAVERSAL = 59,
NODE_TYPE_COLLECTION_LIST = 60,
NODE_TYPE_DIRECTION = 61,
NODE_TYPE_OPERATOR_NARY_AND = 62,
NODE_TYPE_OPERATOR_NARY_OR = 63,
NODE_TYPE_AGGREGATIONS = 64,
NODE_TYPE_OPERATOR_BINARY_ARRAY_EQ = 65,
NODE_TYPE_OPERATOR_BINARY_ARRAY_NE = 66,
NODE_TYPE_OPERATOR_BINARY_ARRAY_LT = 67,
NODE_TYPE_OPERATOR_BINARY_ARRAY_LE = 68,
NODE_TYPE_OPERATOR_BINARY_ARRAY_GT = 69,
NODE_TYPE_OPERATOR_BINARY_ARRAY_GE = 70,
NODE_TYPE_OPERATOR_BINARY_ARRAY_IN = 71,
NODE_TYPE_OPERATOR_BINARY_ARRAY_NIN = 72,
NODE_TYPE_QUANTIFIER = 73,
NODE_TYPE_WITH = 74,
NODE_TYPE_SHORTEST_PATH = 75,
NODE_TYPE_K_SHORTEST_PATHS = 76,
NODE_TYPE_VIEW = 77,
NODE_TYPE_PARAMETER_DATASOURCE = 78,
NODE_TYPE_FOR_VIEW = 79,
};
static_assert(NODE_TYPE_VALUE < NODE_TYPE_ARRAY, "incorrect node types order");
static_assert(NODE_TYPE_ARRAY < NODE_TYPE_OBJECT, "incorrect node types order");
/// @brief the node
struct AstNode {
friend class Ast;
static std::unordered_map<int, std::string const> const Operators;
static std::unordered_map<int, std::string const> const TypeNames;
static std::unordered_map<int, std::string const> const ValueTypeNames;
/// @brief helper for building flags
template <typename... Args>
static inline std::underlying_type<AstNodeFlagType>::type makeFlags(AstNodeFlagType flag,
Args... args) {
return static_cast<std::underlying_type<AstNodeFlagType>::type>(flag) +
makeFlags(args...);
}
static inline std::underlying_type<AstNodeFlagType>::type makeFlags() {
return static_cast<std::underlying_type<AstNodeFlagType>::type>(0);
}
/// @brief create the node
explicit AstNode(AstNodeType);
/// @brief create a node, with defining a value
explicit AstNode(AstNodeValue const& value);
/// @brief create the node from VPack
explicit AstNode(Ast*, arangodb::velocypack::Slice const& slice);
/// @brief create the node from VPack
explicit AstNode(std::function<void(AstNode*)> const& registerNode,
std::function<char const*(std::string const&)> registerString,
arangodb::velocypack::Slice const& slice);
/// @brief destroy the node
~AstNode();
public:
static constexpr size_t SortNumberThreshold = 8;
/// @brief return the string value of a node, as an std::string
std::string getString() const;
/// @brief return the string value of a node, as a arangodb::velocypack::StringRef
arangodb::velocypack::StringRef getStringRef() const noexcept;
/// @brief test if all members of a node are equality comparisons
bool isOnlyEqualityMatch() const;
/// @brief computes a hash value for a value node
uint64_t hashValue(uint64_t) const noexcept;
/// @brief dump the node (for debugging purposes)
#ifdef ARANGODB_ENABLE_MAINTAINER_MODE
std::ostream& toStream(std::ostream& os, int indent) const;
void dump(int indent) const;
#endif
/// @brief compute the value for a constant value node
/// the value is owned by the node and must not be freed by the caller
arangodb::velocypack::Slice computeValue() const;
/// @brief sort the members of an (array) node
/// this will also set the FLAG_SORTED flag for the node
void sort();
/// @brief return the type name of a node
std::string const& getTypeString() const;
/// @brief return the value type name of a node
std::string const& getValueTypeString() const;
/// @brief stringify the AstNode
static std::string toString(AstNode const*);
/// @brief checks whether we know a type of this kind; throws exception if not
static void validateType(int type);
/// @brief checks whether we know a value type of this kind;
/// throws exception if not
static void validateValueType(int type);
/// @brief fetch a node's type from VPack
static AstNodeType getNodeTypeFromVPack(arangodb::velocypack::Slice const& slice);
/// @brief return a VelocyPack representation of the node value
std::shared_ptr<arangodb::velocypack::Builder> toVelocyPackValue() const;
/// @brief build a VelocyPack representation of the node value
/// Can throw Out of Memory Error
void toVelocyPackValue(arangodb::velocypack::Builder&) const;
/// @brief return a VelocyPack representation of the node
std::shared_ptr<arangodb::velocypack::Builder> toVelocyPack(bool) const;
/// @brief Create a VelocyPack representation of the node
void toVelocyPack(arangodb::velocypack::Builder&, bool) const;
/// @brief convert the node's value to a boolean value
/// this may create a new node or return the node itself if it is already a
/// boolean value node
AstNode const* castToBool(Ast*) const;
/// @brief convert the node's value to a number value
/// this may create a new node or return the node itself if it is already a
/// numeric value node
AstNode const* castToNumber(Ast*) const;
/// @brief check a flag for the node
inline bool hasFlag(AstNodeFlagType flag) const {
return ((flags & static_cast<decltype(flags)>(flag)) != 0);
}
/// @brief reset flags in case a node is changed drastically
inline void clearFlags() { flags = 0; }
/// @brief recursively clear flags
void clearFlagsRecursive();
/// @brief set a flag for the node
inline void setFlag(AstNodeFlagType flag) const { flags |= flag; }
/// @brief set two flags for the node
inline void setFlag(AstNodeFlagType typeFlag, AstNodeFlagType valueFlag) const {
flags |= (typeFlag | valueFlag);
}
/// @brief remove a flag for the node
inline void removeFlag(AstNodeFlagType flag) const { flags &= ~flag; }
/// @brief whether or not the node value is trueish
bool isTrue() const;
/// @brief whether or not the node value is falsey
bool isFalse() const;
/// @brief whether or not the members of a list node are sorted
inline bool isSorted() const {
return ((flags & (DETERMINED_SORTED | VALUE_SORTED)) == (DETERMINED_SORTED | VALUE_SORTED));
}
/// @brief whether or not a value node is NULL
inline bool isNullValue() const {
return (type == NODE_TYPE_VALUE && value.type == VALUE_TYPE_NULL);
}
/// @brief whether or not a value node is an integer
inline bool isIntValue() const {
return (type == NODE_TYPE_VALUE && value.type == VALUE_TYPE_INT);
}
/// @brief whether or not a value node is a dobule
inline bool isDoubleValue() const {
return (type == NODE_TYPE_VALUE && value.type == VALUE_TYPE_DOUBLE);
}
/// @brief whether or not a value node is of numeric type
inline bool isNumericValue() const {
return (type == NODE_TYPE_VALUE &&
(value.type == VALUE_TYPE_INT || value.type == VALUE_TYPE_DOUBLE));
}
/// @brief whether or not a value node is of bool type
inline bool isBoolValue() const {
return (type == NODE_TYPE_VALUE && value.type == VALUE_TYPE_BOOL);
}
/// @brief whether or not a value node is of string type
inline bool isStringValue() const {
return (type == NODE_TYPE_VALUE && value.type == VALUE_TYPE_STRING);
}
/// @brief whether or not a value node is of list type
inline bool isArray() const { return (type == NODE_TYPE_ARRAY); }
/// @brief whether or not a value node is of array type
inline bool isObject() const { return (type == NODE_TYPE_OBJECT); }
/// @brief whether or not a value node is of type attribute access that
/// refers to a variable reference
AstNode const* getAttributeAccessForVariable(bool allowIndexedAccess) const {
if (type != NODE_TYPE_ATTRIBUTE_ACCESS && type != NODE_TYPE_EXPANSION &&
!(allowIndexedAccess && type == NODE_TYPE_INDEXED_ACCESS)) {
return nullptr;
}
auto node = this;
while (node->type == NODE_TYPE_ATTRIBUTE_ACCESS ||
(allowIndexedAccess && node->type == NODE_TYPE_INDEXED_ACCESS) ||
node->type == NODE_TYPE_EXPANSION) {
if (node->type == NODE_TYPE_ATTRIBUTE_ACCESS || node->type == NODE_TYPE_INDEXED_ACCESS) {
node = node->getMember(0);
} else {
// expansion, i.e. [*]
TRI_ASSERT(node->type == NODE_TYPE_EXPANSION);
TRI_ASSERT(node->numMembers() >= 2);
if (node->getMember(1)->type != NODE_TYPE_REFERENCE) {
if (node->getMember(1)->getAttributeAccessForVariable(allowIndexedAccess) == nullptr) {
return nullptr;
}
}
TRI_ASSERT(node->getMember(0)->type == NODE_TYPE_ITERATOR);
node = node->getMember(0)->getMember(1);
}
}
if (node->type == NODE_TYPE_REFERENCE) {
return node;
}
return nullptr;
}
/// @brief whether or not a value node is of type attribute access that
/// refers to any variable reference
bool isAttributeAccessForVariable() const {
return (getAttributeAccessForVariable(false) != nullptr);
}
/// @brief whether or not a value node is of type attribute access that
/// refers to the specified variable reference
bool isAttributeAccessForVariable(Variable const* variable, bool allowIndexedAccess) const {
auto node = getAttributeAccessForVariable(allowIndexedAccess);
if (node == nullptr) {
return false;
}
return (static_cast<Variable const*>(node->getData()) == variable);
}
/// @brief whether or not a value node is of type attribute access that
/// refers to any variable reference
/// returns true if yes, and then also returns variable reference and array
/// of attribute names in the parameter passed by reference
bool isAttributeAccessForVariable(
std::pair<Variable const*, std::vector<arangodb::basics::AttributeName>>&,
bool allowIndexedAccess = false) const;
/// @brief locate a variable including the direct path vector leading to it.
void findVariableAccess(std::vector<AstNode const*>& currentPath,
std::vector<std::vector<AstNode const*>>& paths,
Variable const* findme) const;
/// @brief dig through the tree and return a reference to the astnode
/// referencing
/// findme, nullptr otherwise.
AstNode const* findReference(AstNode const* findme) const;
/// @brief whether or not a node is simple enough to be used in a simple
/// expression
/// this may also set the FLAG_SIMPLE flag for the node
bool isSimple() const;
/// @brief whether or not a node has a constant value
/// this may also set the FLAG_CONSTANT or the FLAG_DYNAMIC flags for the node
bool isConstant() const;
/// @brief whether or not a node will use V8 internally
/// this may also set the FLAG_V8 flag for the node
bool willUseV8() const;
/// @brief whether or not a node is a simple comparison operator
bool isSimpleComparisonOperator() const;
/// @brief whether or not a node is a comparison operator
bool isComparisonOperator() const;
/// @brief whether or not a node is an array comparison operator
bool isArrayComparisonOperator() const;
/// @brief whether or not a node (and its subnodes) can safely be executed on
/// a DB server
bool canRunOnDBServer() const;
/// @brief whether or not an object's keys must be checked for uniqueness
bool mustCheckUniqueness() const;
/// @brief whether or not a node (and its subnodes) is deterministic
bool isDeterministic() const;
/// @brief whether or not a node (and its subnodes) is cacheable
bool isCacheable() const;
/// @brief whether or not a node (and its subnodes) may contain a call to a
/// user-defined function
bool callsUserDefinedFunction() const;
/// @brief whether or not a node (and its subnodes) may contain a call to a
/// a function or a user-defined function
bool callsFunction() const;
/// @brief whether or not the object node contains dynamically named
/// attributes
/// on its first level
bool containsDynamicAttributeName() const;
/// @brief iterates whether a node of type "searchType" can be found
bool containsNodeType(AstNodeType searchType) const;
/// @brief return the number of members
inline size_t numMembers() const noexcept { return members.size(); }
/// @brief reserve space for members
void reserve(size_t n) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
members.reserve(n);
}
/// @brief add a member to the node
void addMember(AstNode* node) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
if (node == nullptr) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
}
try {
members.emplace_back(node);
} catch (...) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
}
}
/// @brief add a member to the node
inline void addMember(AstNode const* node) {
addMember(const_cast<AstNode*>(node));
}
/// @brief change a member of the node
void changeMember(size_t i, AstNode* node) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
if (i >= members.size()) {
THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL, "member out of range");
}
members[i] = node;
}
/// @brief remove a member from the node
inline void removeMemberUnchecked(size_t i) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
members.erase(members.begin() + i);
}
/// @brief remove all members from the node at once
void removeMembers() {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
members.clear();
}
/// @brief return a member of the node
inline AstNode* getMember(size_t i) const {
if (i >= members.size()) {
THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL, "member out of range");
}
return getMemberUnchecked(i);
}
/// @brief return a member of the node
inline AstNode* getMemberUnchecked(size_t i) const noexcept {
return members[i];
}
/// @brief sort members with a custom comparison function
void sortMembers(std::function<bool(AstNode const*, AstNode const*)> const& func) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
std::sort(members.begin(), members.end(), func);
}
/// @brief reduces the number of members of the node
void reduceMembers(size_t i) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
if (i > members.size()) {
THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL, "member out of range");
}
members.erase(members.begin() + i, members.end());
}
inline void clearMembers() {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
members.clear();
}
/// @brief mark a < or <= operator to definitely exclude the "null" value
/// this is only for optimization purposes
inline void setExcludesNull(bool v = true) {
TRI_ASSERT(type == NODE_TYPE_OPERATOR_BINARY_LT || type == NODE_TYPE_OPERATOR_BINARY_LE ||
type == NODE_TYPE_OPERATOR_BINARY_EQ);
value.value._bool = v;
}
/// @brief check if an < or <= operator definitely excludes the "null" value
/// this is only for optimization purposes
inline bool getExcludesNull() const noexcept {
TRI_ASSERT(type == NODE_TYPE_OPERATOR_BINARY_LT || type == NODE_TYPE_OPERATOR_BINARY_LE ||
type == NODE_TYPE_OPERATOR_BINARY_EQ);
return value.value._bool;
}
/// @brief set the node's value type
inline void setValueType(AstNodeValueType type) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
value.type = type;
}
/// @brief check whether this node value is of expectedType
inline bool isValueType(AstNodeValueType expectedType) const noexcept {
return value.type == expectedType;
}
/// @brief return the bool value of a node
inline bool getBoolValue() const noexcept { return value.value._bool; }
/// @brief set the bool value of a node
inline void setBoolValue(bool v) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
value.value._bool = v;
}
/// @brief return the int value of a node
/// this will return 0 for all non-value nodes and for all non-int value
/// nodes!!
int64_t getIntValue() const;
/// @brief return the int value stored for a node, regardless of the node type
inline int64_t getIntValue(bool) const noexcept { return value.value._int; }
/// @brief set the int value of a node
inline void setIntValue(int64_t v) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
value.value._int = v;
}
/// @brief return the double value of a node
double getDoubleValue() const;
/// @brief set the string value of a node
inline void setDoubleValue(double v) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
value.value._double = v;
}
/// @brief return the string value of a node
inline char const* getStringValue() const { return value.value._string; }
/// @brief return the string value of a node
inline size_t getStringLength() const {
return static_cast<size_t>(value.length);
}
/// @brief set the string value of a node
inline void setStringValue(char const* v, size_t length) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
// note: v may contain the NUL byte and is not necessarily
// null-terminated itself (if from VPack)
value.type = VALUE_TYPE_STRING;
value.value._string = v;
value.length = static_cast<uint32_t>(length);
}
/// @brief whether or not a string is equal to another
inline bool stringEquals(char const* other, bool caseInsensitive) const {
if (caseInsensitive) {
return (strncasecmp(getStringValue(), other, getStringLength()) == 0);
}
return (strncmp(getStringValue(), other, getStringLength()) == 0);
}
/// @brief whether or not a string is equal to another
inline bool stringEquals(std::string const& other) const {
return (other.size() == getStringLength() &&
memcmp(other.c_str(), getStringValue(), getStringLength()) == 0);
}
/// @brief return the data value of a node
inline void* getData() const { return value.value._data; }
/// @brief set the data value of a node
inline void setData(void* v) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
value.value._data = v;
}
/// @brief set the data value of a node
inline void setData(void const* v) {
TRI_ASSERT(!hasFlag(AstNodeFlagType::FLAG_FINALIZED));
value.value._data = const_cast<void*>(v);
}
/// @brief clone a node, recursively
AstNode* clone(Ast*) const;
/// @brief validate that given node is an object with const-only values
bool isConstObject() const;
/// @brief append a string representation of the node into a string buffer
/// the string representation does not need to be JavaScript-compatible
/// except for node types NODE_TYPE_VALUE, NODE_TYPE_ARRAY and
/// NODE_TYPE_OBJECT (only for objects that do not contain dynamic attributes)
/// note that this may throw and that the caller is responsible for
/// catching the error
void stringify(arangodb::basics::StringBuffer*, bool, bool) const;
/// note that this may throw and that the caller is responsible for
/// catching the error
std::string toString() const;
/// @brief stringify the value of a node into a string buffer
/// this method is used when generated JavaScript code for the node!
/// this creates an equivalent to what JSON.stringify() would do
void appendValue(arangodb::basics::StringBuffer*) const;
/// @brief Steals the computed value and frees it.
void stealComputedValue();
/// @brief Removes all members from the current node that are also
/// members of the other node (ignoring ordering)
/// Can only be applied if this and other are of type
/// n-ary-and
void removeMembersInOtherAndNode(AstNode const* other);
/// @brief If the node has not been marked finalized, mark its subtree so.
/// If it runs into a finalized node, it assumes the whole subtree beneath
/// it is marked already and exits early; otherwise it will finalize the node
/// and recurse on its subtree.
static void markFinalized(AstNode* subtreeRoot);
public:
/// @brief the node type
AstNodeType type;
/// @brief flags for the node
AstNodeFlagsType mutable flags;
/// @brief the node value
AstNodeValue value;
private:
/// @brief precomputed VPack value (used when executing expressions)
uint8_t mutable* computedValue;
/// @brief the node's sub nodes
std::vector<AstNode*> members;
};
int CompareAstNodes(AstNode const* lhs, AstNode const* rhs, bool compareUtf8);
/// @brief less comparator for Ast value nodes
template <bool useUtf8>
struct AstNodeValueLess {
inline bool operator()(AstNode const* lhs, AstNode const* rhs) const {
return CompareAstNodes(lhs, rhs, useUtf8) < 0;
}
};
struct AstNodeValueHash {
inline size_t operator()(AstNode const* value) const noexcept {
return static_cast<size_t>(value->hashValue(0x12345678));
}
};
struct AstNodeValueEqual {
inline bool operator()(AstNode const* lhs, AstNode const* rhs) const {
return CompareAstNodes(lhs, rhs, false) == 0;
}
};
} // namespace aql
} // namespace arangodb
/// @brief append the AstNode to an output stream
std::ostream& operator<<(std::ostream&, arangodb::aql::AstNode const*);
std::ostream& operator<<(std::ostream&, arangodb::aql::AstNode const&);
/** README
* Typically, the pattern should be that once an AstNode is created and inserted
* into the tree, it is immutable. Currently there are some places where this
* is not the case, so we cannot currently enforce it via typing.
*
* Instead, we have a flag which we set and check only in maintainer mode,
* `FLAG_FINALIZED` to signal that the node should not change state. This allows
* us to take a more functional style approach to building and modifying the
* Ast, allowing us to simply point to the same node multiple times instead of
* creating several copies when we need to e.g. distribute an AND operation.
*
* If you need to modify a node, try to replace it with a new one. You can
* create a copy-for-modify node via `Ast::shallowCopyForModify`. You can then
* set it to be finalized when it goes out of scope using
* `TRI_DEFER(FINALIZE_SUBTREE(node))`.
*
* If you cannot follow this pattern, for instance if you do not have access
* to the Ast or to the node's ancestors, then you might be able to get away
* with temporarily unlocking the node and modifying it in place. This could
* create correctness issues in our optmization code though, so do this with
* extreme caution. The correct way to do this is via the
* `TEMPORARILY_UNLOCK_NODE(node)` macro. It will relock the node when the macro
* instance goes out of scope.
*/
#ifdef ARANGODB_ENABLE_MAINTAINER_MODE
#define FINALIZE_SUBTREE(n) \
arangodb::aql::AstNode::markFinalized(const_cast<arangodb::aql::AstNode*>(n))
#define FINALIZE_SUBTREE_CONDITIONAL(n, b) \
if (b) { \
FINALIZE_SUBTREE(n); \
}
#define TEMPORARILY_UNLOCK_NODE(n) \
bool wasFinalizedAlready = (n)->hasFlag(arangodb::aql::AstNodeFlagType::FLAG_FINALIZED); \
if (wasFinalizedAlready) { \
(n)->flags = ((n)->flags & ~arangodb::aql::AstNodeFlagType::FLAG_FINALIZED); \
} \
TRI_DEFER(FINALIZE_SUBTREE_CONDITIONAL(n, wasFinalizedAlready));
#else
#define FINALIZE_SUBTREE(n) \
while (0) { \
(void)(n); \
} \
do { \
} while (0)
#define FINALIZE_SUBTREE_CONDITIONAL(n, b) \
while (0) { \
(void)(n); \
} \
do { \
} while (0)
#define TEMPORARILY_UNLOCK_NODE(n) \
while (0) { \
(void)(n); \
} \
do { \
} while (0)
#endif
#endif
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