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//===-- MsgPackDocument.h - MsgPack Document --------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
/// This file declares a class that exposes a simple in-memory representation
/// of a document of MsgPack objects, that can be read from MsgPack, written to
/// MsgPack, and inspected and modified in memory. This is intended to be a
/// lighter-weight (in terms of memory allocations) replacement for
/// MsgPackTypes.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_BINARYFORMAT_MSGPACKDOCUMENT_H
#define LLVM_BINARYFORMAT_MSGPACKDOCUMENT_H
#include "llvm/BinaryFormat/MsgPackReader.h"
#include <map>
namespace llvm {
namespace msgpack {
class ArrayDocNode;
class Document;
class MapDocNode;
/// The kind of a DocNode and its owning Document.
struct KindAndDocument {
Document *Doc;
Type Kind;
};
/// A node in a MsgPack Document. This is a simple copyable and
/// passable-by-value type that does not own any memory.
class DocNode {
friend Document;
public:
typedef std::map<DocNode, DocNode> MapTy;
typedef std::vector<DocNode> ArrayTy;
private:
// Using KindAndDocument allows us to squeeze Kind and a pointer to the
// owning Document into the same word. Having a pointer to the owning
// Document makes the API of DocNode more convenient, and allows its use in
// YAMLIO.
const KindAndDocument *KindAndDoc;
protected:
// The union of different values.
union {
int64_t Int;
uint64_t UInt;
bool Bool;
double Float;
StringRef Raw;
ArrayTy *Array;
MapTy *Map;
};
public:
// Default constructor gives an empty node with no associated Document. All
// you can do with it is "isEmpty()".
DocNode() : KindAndDoc(nullptr) {}
// Type methods
bool isMap() const { return getKind() == Type::Map; }
bool isArray() const { return getKind() == Type::Array; }
bool isScalar() const { return !isMap() && !isArray(); }
bool isString() const { return getKind() == Type::String; }
// Accessors. isEmpty() returns true for both a default-constructed DocNode
// that has no associated Document, and the result of getEmptyNode(), which
// does have an associated document.
bool isEmpty() const { return !KindAndDoc || getKind() == Type::Empty; }
Type getKind() const { return KindAndDoc->Kind; }
Document *getDocument() const { return KindAndDoc->Doc; }
int64_t &getInt() {
assert(getKind() == Type::Int);
return Int;
}
uint64_t &getUInt() {
assert(getKind() == Type::UInt);
return UInt;
}
bool &getBool() {
assert(getKind() == Type::Boolean);
return Bool;
}
double &getFloat() {
assert(getKind() == Type::Float);
return Float;
}
int64_t getInt() const {
assert(getKind() == Type::Int);
return Int;
}
uint64_t getUInt() const {
assert(getKind() == Type::UInt);
return UInt;
}
bool getBool() const {
assert(getKind() == Type::Boolean);
return Bool;
}
double getFloat() const {
assert(getKind() == Type::Float);
return Float;
}
StringRef getString() const {
assert(getKind() == Type::String);
return Raw;
}
MemoryBufferRef getBinary() const {
assert(getKind() == Type::Binary);
return MemoryBufferRef(Raw, "");
}
/// Get an ArrayDocNode for an array node. If Convert, convert the node to an
/// array node if necessary.
ArrayDocNode &getArray(bool Convert = false) {
if (getKind() != Type::Array) {
assert(Convert);
convertToArray();
}
// This could be a static_cast, except ArrayDocNode is a forward reference.
return *reinterpret_cast<ArrayDocNode *>(this);
}
/// Get a MapDocNode for a map node. If Convert, convert the node to a map
/// node if necessary.
MapDocNode &getMap(bool Convert = false) {
if (getKind() != Type::Map) {
assert(Convert);
convertToMap();
}
// This could be a static_cast, except MapDocNode is a forward reference.
return *reinterpret_cast<MapDocNode *>(this);
}
/// Comparison operator, used for map keys.
friend bool operator<(const DocNode &Lhs, const DocNode &Rhs) {
// This has to cope with one or both of the nodes being default-constructed,
// such that KindAndDoc is not set.
if (Rhs.isEmpty())
return false;
if (Lhs.KindAndDoc != Rhs.KindAndDoc) {
if (Lhs.isEmpty())
return true;
return (unsigned)Lhs.getKind() < (unsigned)Rhs.getKind();
}
switch (Lhs.getKind()) {
case Type::Int:
return Lhs.Int < Rhs.Int;
case Type::UInt:
return Lhs.UInt < Rhs.UInt;
case Type::Nil:
return false;
case Type::Boolean:
return Lhs.Bool < Rhs.Bool;
case Type::Float:
return Lhs.Float < Rhs.Float;
case Type::String:
case Type::Binary:
return Lhs.Raw < Rhs.Raw;
default:
llvm_unreachable("bad map key type");
}
}
/// Equality operator
friend bool operator==(const DocNode &Lhs, const DocNode &Rhs) {
return !(Lhs < Rhs) && !(Rhs < Lhs);
}
/// Inequality operator
friend bool operator!=(const DocNode &Lhs, const DocNode &Rhs) {
return !(Lhs == Rhs);
}
/// Convert this node to a string, assuming it is scalar.
std::string toString() const;
/// Convert the StringRef and use it to set this DocNode (assuming scalar). If
/// it is a string, copy the string into the Document's strings list so we do
/// not rely on S having a lifetime beyond this call. Tag is "" or a YAML tag.
StringRef fromString(StringRef S, StringRef Tag = "");
/// Convenience assignment operators. This only works if the destination
/// DocNode has an associated Document, i.e. it was not constructed using the
/// default constructor. The string one does not copy, so the string must
/// remain valid for the lifetime of the Document. Use fromString to avoid
/// that restriction.
DocNode &operator=(const char *Val) { return *this = StringRef(Val); }
DocNode &operator=(StringRef Val);
DocNode &operator=(MemoryBufferRef Val);
DocNode &operator=(bool Val);
DocNode &operator=(int Val);
DocNode &operator=(unsigned Val);
DocNode &operator=(int64_t Val);
DocNode &operator=(uint64_t Val);
private:
// Private constructor setting KindAndDoc, used by methods in Document.
DocNode(const KindAndDocument *KindAndDoc) : KindAndDoc(KindAndDoc) {}
void convertToArray();
void convertToMap();
};
/// A DocNode that is a map.
class MapDocNode : public DocNode {
public:
MapDocNode() = default;
MapDocNode(DocNode &N) : DocNode(N) { assert(getKind() == Type::Map); }
// Map access methods.
size_t size() const { return Map->size(); }
bool empty() const { return !size(); }
MapTy::iterator begin() { return Map->begin(); }
MapTy::iterator end() { return Map->end(); }
MapTy::iterator find(DocNode Key) { return Map->find(Key); }
MapTy::iterator find(StringRef Key);
MapTy::iterator erase(MapTy::const_iterator I) { return Map->erase(I); }
size_t erase(DocNode Key) { return Map->erase(Key); }
MapTy::iterator erase(MapTy::const_iterator First,
MapTy::const_iterator Second) {
return Map->erase(First, Second);
}
/// Member access. The string data must remain valid for the lifetime of the
/// Document.
DocNode &operator[](StringRef S);
/// Member access, with convenience versions for an integer key.
DocNode &operator[](DocNode Key);
DocNode &operator[](int Key);
DocNode &operator[](unsigned Key);
DocNode &operator[](int64_t Key);
DocNode &operator[](uint64_t Key);
};
/// A DocNode that is an array.
class ArrayDocNode : public DocNode {
public:
ArrayDocNode() = default;
ArrayDocNode(DocNode &N) : DocNode(N) { assert(getKind() == Type::Array); }
// Array access methods.
size_t size() const { return Array->size(); }
bool empty() const { return !size(); }
DocNode &back() const { return Array->back(); }
ArrayTy::iterator begin() { return Array->begin(); }
ArrayTy::iterator end() { return Array->end(); }
void push_back(DocNode N) {
assert(N.isEmpty() || N.getDocument() == getDocument());
Array->push_back(N);
}
/// Element access. This extends the array if necessary, with empty nodes.
DocNode &operator[](size_t Index);
};
/// Simple in-memory representation of a document of msgpack objects with
/// ability to find and create array and map elements. Does not currently cope
/// with any extension types.
class Document {
// Maps, arrays and strings used by nodes in the document. No attempt is made
// to free unused ones.
std::vector<std::unique_ptr<DocNode::MapTy>> Maps;
std::vector<std::unique_ptr<DocNode::ArrayTy>> Arrays;
std::vector<std::unique_ptr<char[]>> Strings;
// The root node of the document.
DocNode Root;
// The KindAndDocument structs pointed to by nodes in the document.
KindAndDocument KindAndDocs[size_t(Type::Empty) + 1];
// Whether YAML output uses hex for UInt.
bool HexMode = false;
public:
Document() {
clear();
for (unsigned T = 0; T != unsigned(Type::Empty) + 1; ++T)
KindAndDocs[T] = {this, Type(T)};
}
/// Get ref to the document's root element.
DocNode &getRoot() { return Root; }
/// Restore the Document to an empty state.
void clear() { getRoot() = getEmptyNode(); }
/// Create an empty node associated with this Document.
DocNode getEmptyNode() {
auto N = DocNode(&KindAndDocs[size_t(Type::Empty)]);
return N;
}
/// Create a nil node associated with this Document.
DocNode getNode() {
auto N = DocNode(&KindAndDocs[size_t(Type::Nil)]);
return N;
}
/// Create an Int node associated with this Document.
DocNode getNode(int64_t V) {
auto N = DocNode(&KindAndDocs[size_t(Type::Int)]);
N.Int = V;
return N;
}
/// Create an Int node associated with this Document.
DocNode getNode(int V) {
auto N = DocNode(&KindAndDocs[size_t(Type::Int)]);
N.Int = V;
return N;
}
/// Create a UInt node associated with this Document.
DocNode getNode(uint64_t V) {
auto N = DocNode(&KindAndDocs[size_t(Type::UInt)]);
N.UInt = V;
return N;
}
/// Create a UInt node associated with this Document.
DocNode getNode(unsigned V) {
auto N = DocNode(&KindAndDocs[size_t(Type::UInt)]);
N.UInt = V;
return N;
}
/// Create a Boolean node associated with this Document.
DocNode getNode(bool V) {
auto N = DocNode(&KindAndDocs[size_t(Type::Boolean)]);
N.Bool = V;
return N;
}
/// Create a Float node associated with this Document.
DocNode getNode(double V) {
auto N = DocNode(&KindAndDocs[size_t(Type::Float)]);
N.Float = V;
return N;
}
/// Create a String node associated with this Document. If !Copy, the passed
/// string must remain valid for the lifetime of the Document.
DocNode getNode(StringRef V, bool Copy = false) {
if (Copy)
V = addString(V);
auto N = DocNode(&KindAndDocs[size_t(Type::String)]);
N.Raw = V;
return N;
}
/// Create a String node associated with this Document. If !Copy, the passed
/// string must remain valid for the lifetime of the Document.
DocNode getNode(const char *V, bool Copy = false) {
return getNode(StringRef(V), Copy);
}
/// Create a Binary node associated with this Document. If !Copy, the passed
/// buffer must remain valid for the lifetime of the Document.
DocNode getNode(MemoryBufferRef V, bool Copy = false) {
auto Raw = V.getBuffer();
if (Copy)
Raw = addString(Raw);
auto N = DocNode(&KindAndDocs[size_t(Type::Binary)]);
N.Raw = Raw;
return N;
}
/// Create an empty Map node associated with this Document.
MapDocNode getMapNode() {
auto N = DocNode(&KindAndDocs[size_t(Type::Map)]);
Maps.push_back(std::make_unique<DocNode::MapTy>());
N.Map = Maps.back().get();
return N.getMap();
}
/// Create an empty Array node associated with this Document.
ArrayDocNode getArrayNode() {
auto N = DocNode(&KindAndDocs[size_t(Type::Array)]);
Arrays.push_back(std::make_unique<DocNode::ArrayTy>());
N.Array = Arrays.back().get();
return N.getArray();
}
/// Read a document from a binary msgpack blob, merging into anything already
/// in the Document. The blob data must remain valid for the lifetime of this
/// Document (because a string object in the document contains a StringRef
/// into the original blob). If Multi, then this sets root to an array and
/// adds top-level objects to it. If !Multi, then it only reads a single
/// top-level object, even if there are more, and sets root to that. Returns
/// false if failed due to illegal format or merge error.
///
/// The Merger arg is a callback function that is called when the merge has a
/// conflict, that is, it is trying to set an item that is already set. If the
/// conflict cannot be resolved, the callback function returns -1. If the
/// conflict can be resolved, the callback returns a non-negative number and
/// sets *DestNode to the resolved node. The returned non-negative number is
/// significant only for an array node; it is then the array index to start
/// populating at. That allows Merger to choose whether to merge array
/// elements (returns 0) or append new elements (returns existing size).
///
/// If SrcNode is an array or map, the resolution must be that *DestNode is an
/// array or map respectively, although it could be the array or map
/// (respectively) that was already there. MapKey is the key if *DestNode is a
/// map entry, a nil node otherwise.
///
/// The default for Merger is to disallow any conflict.
bool readFromBlob(
StringRef Blob, bool Multi,
function_ref<int(DocNode *DestNode, DocNode SrcNode, DocNode MapKey)>
Merger = [](DocNode *DestNode, DocNode SrcNode, DocNode MapKey) {
return -1;
});
/// Write a MsgPack document to a binary MsgPack blob.
void writeToBlob(std::string &Blob);
/// Copy a string into the Document's strings list, and return the copy that
/// is owned by the Document.
StringRef addString(StringRef S) {
Strings.push_back(std::unique_ptr<char[]>(new char[S.size()]));
memcpy(&Strings.back()[0], S.data(), S.size());
return StringRef(&Strings.back()[0], S.size());
}
/// Set whether YAML output uses hex for UInt. Default off.
void setHexMode(bool Val = true) { HexMode = Val; }
/// Get Hexmode flag.
bool getHexMode() const { return HexMode; }
/// Convert MsgPack Document to YAML text.
void toYAML(raw_ostream &OS);
/// Read YAML text into the MsgPack document. Returns false on failure.
bool fromYAML(StringRef S);
};
} // namespace msgpack
} // namespace llvm
#endif // LLVM_BINARYFORMAT_MSGPACKDOCUMENT_H
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