GenericPointer< ValueType, Allocator >

Represents a JSON Pointer. Use Pointer for UTF8 encoding and default allocator. More...

#include <fwd.h>

Collaboration diagram for GenericPointer< ValueType, Allocator >:

Classes
class	PercentEncodeStream
	A helper stream to encode character (UTF-8 code unit) into percent-encoded sequence. More...
struct	Token
	A token is the basic units of internal representation. More...

Public Types
typedef ValueType::EncodingType	EncodingType
	Encoding type from Value. More...
typedef ValueType::Ch	Ch
	Character type from Value. More...

Public Member Functions
Append token
GenericPointer	Append (const Token &token, Allocator *allocator=0) const
	Append a token and return a new Pointer. More...
GenericPointer	Append (const Ch *name, SizeType length, Allocator *allocator=0) const
	Append a name token with length, and return a new Pointer. More...
template<typename T >
	RAPIDJSON_DISABLEIF_RETURN ((internal::NotExpr< internal::IsSame< typename internal::RemoveConst< T >::Type, Ch > >),(GenericPointer)) Append(T *name
	Append a name token without length, and return a new Pointer. More...

Public Attributes
Allocator *	allocator
Allocator *	allocator_
	The current allocator. It is either user-supplied or equal to ownAllocator_. More...
Allocator *	ownAllocator_
	Allocator owned by this Pointer. More...
Ch *	nameBuffer_
	A buffer containing all names in tokens. More...
Token *	tokens_
	A list of tokens. More...
size_t	tokenCount_
	Number of tokens in tokens_. More...
size_t	parseErrorOffset_
	Offset in code unit when parsing fail. More...
PointerParseErrorCode	parseErrorCode_
	Parsing error code. More...

Constructors and destructor.
	GenericPointer (Allocator *allocator=0)
	Default constructor. More...
	GenericPointer (const Ch *source, Allocator *allocator=0)
	Constructor that parses a string or URI fragment representation. More...
	GenericPointer (const Ch *source, size_t length, Allocator *allocator=0)
	Constructor that parses a string or URI fragment representation, with length of the source string. More...
	GenericPointer (const Token *tokens, size_t tokenCount)
	Constructor with user-supplied tokens. More...
	GenericPointer (const GenericPointer &rhs)
	Copy constructor. More...
	GenericPointer (const GenericPointer &rhs, Allocator *allocator)
	Copy constructor. More...
	~GenericPointer ()
	Destructor. More...
GenericPointer &	operator= (const GenericPointer &rhs)
	Assignment operator. More...
GenericPointer &	Swap (GenericPointer &other) RAPIDJSON_NOEXCEPT
	Swap the content of this pointer with an other. More...
void	swap (GenericPointer &a, GenericPointer &b) RAPIDJSON_NOEXCEPT
	free-standing swap function helper More...

Detailed Description

template<typename ValueType, typename Allocator = CrtAllocator>
class GenericPointer< ValueType, Allocator >

Represents a JSON Pointer. Use Pointer for UTF8 encoding and default allocator.

This class implements RFC 6901 "JavaScript Object Notation (JSON) Pointer" (https://tools.ietf.org/html/rfc6901).

A JSON pointer is for identifying a specific value in a JSON document (GenericDocument). It can simplify coding of DOM tree manipulation, because it can access multiple-level depth of DOM tree with single API call.

After it parses a string representation (e.g. "/foo/0" or URI fragment representation (e.g. "#/foo/0") into its internal representation (tokens), it can be used to resolve a specific value in multiple documents, or sub-tree of documents.

Contrary to GenericValue, Pointer can be copy constructed and copy assigned. Apart from assignment, a Pointer cannot be modified after construction.

Although Pointer is very convenient, please aware that constructing Pointer involves parsing and dynamic memory allocation. A special constructor with user- supplied tokens eliminates these.

GenericPointer depends on GenericDocument and GenericValue.

Template Parameters

ValueType	The value type of the DOM tree. E.g. GenericValue<UTF8<> >
Allocator	The allocator type for allocating memory for internal representation.

Note

GenericPointer uses same encoding of ValueType. However, Allocator of GenericPointer is independent of Allocator of Value.

Definition at line 126 of file fwd.h.

Member Typedef Documentation

Ch

typedef ValueType::Ch Ch

Character type from Value.

Definition at line 82 of file pointer.h.

EncodingType

typedef ValueType::EncodingType EncodingType

Encoding type from Value.

Definition at line 81 of file pointer.h.

Constructor & Destructor Documentation

GenericPointer() [1/6]

GenericPointer ( Allocator *  allocator = 0 )

inline

Default constructor.

Definition at line 107 of file pointer.h.

: allocator_(allocator), ownAllocator_(), nameBuffer_(), tokens_(), tokenCount_(), parseErrorOffset_(), parseErrorCode_(kPointerParseErrorNone) {}

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GenericPointer() [2/6]

GenericPointer ( const Ch *  source, Allocator *  allocator = 0  )

inlineexplicit

Constructor that parses a string or URI fragment representation.

Parameters

source	A null-terminated, string or URI fragment representation of JSON pointer.
allocator	User supplied allocator for this pointer. If no allocator is provided, it creates a self-owned one.

Definition at line 114 of file pointer.h.

                                                                        : allocator_(allocator), ownAllocator_(), nameBuffer_(), tokens_(), tokenCount_(), parseErrorOffset_(), parseErrorCode_(kPointerParseErrorNone) {
        Parse(source, internal::StrLen(source));
    }

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GenericPointer() [3/6]

GenericPointer ( const Ch *  source, size_t  length, Allocator *  allocator = 0  )

inline

Constructor that parses a string or URI fragment representation, with length of the source string.

Parameters

source	A string or URI fragment representation of JSON pointer.
length	Length of source.
allocator	User supplied allocator for this pointer. If no allocator is provided, it creates a self-owned one.

Note

Slightly faster than the overload without length.

Definition at line 137 of file pointer.h.

                                                                              : allocator_(allocator), ownAllocator_(), nameBuffer_(), tokens_(), tokenCount_(), parseErrorOffset_(), parseErrorCode_(kPointerParseErrorNone) {
        Parse(source, length);
    }

GenericPointer() [4/6]

GenericPointer ( const Token *  tokens, size_t  tokenCount  )

inline

Constructor with user-supplied tokens.

This constructor let user supplies const array of tokens. This prevents the parsing process and eliminates allocation. This is preferred for memory constrained environments.

Parameters

tokens	An constant array of tokens representing the JSON pointer.
tokenCount	Number of tokens.

Example

#define NAME(s) { s, sizeof(s) / sizeof(s[0]) - 1, kPointerInvalidIndex }
#define INDEX(i) { #i, sizeof(#i) - 1, i }

static const Pointer::Token kTokens[] = { NAME("foo"), INDEX(123) };
static const Pointer p(kTokens, sizeof(kTokens) / sizeof(kTokens[0]));
// Equivalent to static const Pointer p("/foo/123");

#undef NAME
#undef INDEX

Definition at line 163 of file pointer.h.

: allocator_(), ownAllocator_(), nameBuffer_(), tokens_(const_cast<Token*>(tokens)), tokenCount_(tokenCount), parseErrorOffset_(), parseErrorCode_(kPointerParseErrorNone) {}

GenericPointer() [5/6]

GenericPointer ( const GenericPointer< ValueType, Allocator > &  rhs )

inline

Copy constructor.

Definition at line 166 of file pointer.h.

                                              : allocator_(rhs.allocator_), ownAllocator_(), nameBuffer_(), tokens_(), tokenCount_(), parseErrorOffset_(), parseErrorCode_(kPointerParseErrorNone) {
        *this = rhs;
    }

GenericPointer() [6/6]

GenericPointer ( const GenericPointer< ValueType, Allocator > &  rhs, Allocator *  allocator  )

inline

Copy constructor.

Definition at line 171 of file pointer.h.

                                                                    : allocator_(allocator), ownAllocator_(), nameBuffer_(), tokens_(), tokenCount_(), parseErrorOffset_(), parseErrorCode_(kPointerParseErrorNone) {
        *this = rhs;
    }

~GenericPointer()

~GenericPointer ( )

inline

Destructor.

Definition at line 176 of file pointer.h.

                      {
        if (nameBuffer_)    // If user-supplied tokens constructor is used, nameBuffer_ is nullptr and tokens_ are not deallocated.
            Allocator::Free(tokens_);
        RAPIDJSON_DELETE(ownAllocator_);
    }

Member Function Documentation

Append() [1/2]

GenericPointer Append ( const Token &  token, Allocator *  allocator = 0  ) const

inline

Append a token and return a new Pointer.

Parameters

token	Token to be appended.
allocator	Allocator for the newly return Pointer.

Returns

A new Pointer with appended token.

Definition at line 244 of file pointer.h.

                                                                              {
        GenericPointer r;
        r.allocator_ = allocator;
        Ch *p = r.CopyFromRaw(*this, 1, token.length + 1);
        std::memcpy(p, token.name, (token.length + 1) * sizeof(Ch));
        r.tokens_[tokenCount_].name = p;
        r.tokens_[tokenCount_].length = token.length;
        r.tokens_[tokenCount_].index = token.index;
        return r;
    }

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Append() [2/2]

GenericPointer Append ( const Ch *  name, SizeType  length, Allocator *  allocator = 0  ) const

inline

Append a name token with length, and return a new Pointer.

Parameters

name	Name to be appended.
length	Length of name.
allocator	Allocator for the newly return Pointer.

Returns

A new Pointer with appended token.

Definition at line 262 of file pointer.h.

                                                                                           {
        Token token = { name, length, kPointerInvalidIndex };
        return Append(token, allocator);
    }

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operator=()

GenericPointer& operator= ( const GenericPointer< ValueType, Allocator > &  rhs )

inline

Assignment operator.

Definition at line 183 of file pointer.h.

                                                         {
        if (this != &rhs) {
            // Do not delete ownAllcator
            if (nameBuffer_)
                Allocator::Free(tokens_);

            tokenCount_ = rhs.tokenCount_;
            parseErrorOffset_ = rhs.parseErrorOffset_;
            parseErrorCode_ = rhs.parseErrorCode_;

            if (rhs.nameBuffer_)
                CopyFromRaw(rhs); // Normally parsed tokens.
            else {
                tokens_ = rhs.tokens_; // User supplied const tokens.
                nameBuffer_ = 0;
            }
        }
        return *this;
    }

RAPIDJSON_DISABLEIF_RETURN()

RAPIDJSON_DISABLEIF_RETURN	(	(internal::NotExpr< internal::IsSame< typename internal::RemoveConst< T >::Type, Ch > >)	,
		(GenericPointer< ValueType, Allocator >)
	)

Append a name token without length, and return a new Pointer.

Parameters

name	Name (const Ch*) to be appended.
allocator	Allocator for the newly return Pointer.

Returns

A new Pointer with appended token.

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Swap()

GenericPointer& Swap ( GenericPointer< ValueType, Allocator > &  other )

inline

Swap the content of this pointer with an other.

Parameters

other

The pointer to swap with.

Note

Constant complexity.

Definition at line 208 of file pointer.h.

                                                                   {
        internal::Swap(allocator_, other.allocator_);
        internal::Swap(ownAllocator_, other.ownAllocator_);
        internal::Swap(nameBuffer_, other.nameBuffer_);
        internal::Swap(tokens_, other.tokens_);
        internal::Swap(tokenCount_, other.tokenCount_);
        internal::Swap(parseErrorOffset_, other.parseErrorOffset_);
        internal::Swap(parseErrorCode_, other.parseErrorCode_);
        return *this;
    }

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Friends And Related Function Documentation

swap

void swap ( GenericPointer< ValueType, Allocator > &  a, GenericPointer< ValueType, Allocator > &  b  )

friend

free-standing swap function helper

Helper function to enable support for common swap implementation pattern based on std::swap:

void swap(MyClass& a, MyClass& b) {
    using std::swap;
    swap(a.pointer, b.pointer);
    // ...
}

See also

Swap()

Definition at line 231 of file pointer.h.

{ a.Swap(b); }

Member Data Documentation

allocator

Allocator* allocator

Definition at line 275 of file pointer.h.

allocator_

Allocator* allocator_

The current allocator. It is either user-supplied or equal to ownAllocator_.

Definition at line 1099 of file pointer.h.

nameBuffer_

Ch* nameBuffer_

A buffer containing all names in tokens.

Definition at line 1101 of file pointer.h.

ownAllocator_

Allocator* ownAllocator_

Allocator owned by this Pointer.

Definition at line 1100 of file pointer.h.

parseErrorCode_

PointerParseErrorCode parseErrorCode_

Parsing error code.

Definition at line 1105 of file pointer.h.

parseErrorOffset_

size_t parseErrorOffset_

Offset in code unit when parsing fail.

Definition at line 1104 of file pointer.h.

tokenCount_

size_t tokenCount_

Number of tokens in tokens_.

Definition at line 1103 of file pointer.h.

tokens_

Token* tokens_

A list of tokens.

Definition at line 1102 of file pointer.h.

---

The documentation for this class was generated from the following files:

• rapidjson/fwd.h
• rapidjson/pointer.h