Abstraction for accessing JSON values irrespective of whether they are (started out as) binary JSON values or JSON DOM values. More...

#include <json_dom.h>

Public Member Functions
const char *	get_datetime_packed (char *buffer) const
	Get the wrapped datetime value in the packed format. More...

	Json_wrapper ()
	Create an empty wrapper. More...

	Json_wrapper (Json_dom *dom_value, bool alias=false)
	Wrap the supplied DOM value (no copy taken). More...

	Json_wrapper (Json_dom_ptr dom_value)
	Wrap the supplied DOM value. More...

void	set_alias ()
	Only meaningful iff the wrapper encapsulates a DOM. More...

	Json_wrapper (const json_binary::Value &value)
	Wrap a binary value. More...

	Json_wrapper (const Json_wrapper &old)
	Copy constructor. More...

	Json_wrapper (Json_wrapper &&old) noexcept
	Move constructor. More...

Json_wrapper &	operator= (const Json_wrapper &old)
	Assignment operator. More...

Json_wrapper &	operator= (Json_wrapper &&old) noexcept
	Move-assignment operator. More...

	~Json_wrapper ()

bool	empty () const
	A Wrapper is defined to be empty if it is passed a NULL value with the constructor for JSON dom, or if the default constructor is used. More...

bool	is_dom () const
	Does this wrapper contain a DOM? More...

Json_dom *	to_dom ()
	Get the wrapped contents in DOM form. More...

const Json_dom *	get_dom () const
	Gets a pointer to the wrapped Json_dom object, if this wrapper holds a DOM. More...

const json_binary::Value &	get_binary_value () const
	Gets the wrapped json_binary::Value object, if this wrapper holds a binary JSON value. More...

Json_dom_ptr	clone_dom () const
	Get the wrapped contents in DOM form. More...

bool	to_binary (const THD thd, String str) const
	Get the wrapped contents in binary value form. More...

bool	is_binary_backed_by (const String *str) const
	Check if the wrapped JSON document is a binary value (a json_binary::Value), and if that binary is pointing to data stored in the given string. More...

bool	to_string (String buffer, bool json_quoted, const char func_name, const JsonDocumentDepthHandler &depth_handler) const
	Format the JSON value to an external JSON string in buffer in the format of ISO/IEC 10646. More...

void	dbug_print (const char *message, const JsonDocumentDepthHandler &depth_handler) const
	Print this JSON document to the debug trace. More...

bool	to_pretty_string (String buffer, const char func_name, const JsonDocumentDepthHandler &depth_handler) const
	Format the JSON value to an external JSON string in buffer in the format of ISO/IEC 10646. More...

enum_json_type	type () const
	Return the type of the wrapped JSON value. More...

enum_field_types	field_type () const
	Return the MYSQL type of the opaque value, see type(). More...

Json_wrapper	operator[] (size_t index) const
	If this wrapper holds a JSON array, get an array value by indexing into the array. More...

Json_wrapper	lookup (const MYSQL_LEX_CSTRING &key) const
	If this wrapper holds a JSON object, get the value corresponding to the member key. More...

const char *	get_data () const
	Get a pointer to the data of a JSON string or JSON opaque value. More...

size_t	get_data_length () const
	Get the length to the data of a JSON string or JSON opaque value. More...

bool	get_decimal_data (my_decimal *d) const
	Get the MySQL representation of a JSON decimal value. More...

double	get_double () const
	Get the value of a JSON double number. More...

longlong	get_int () const
	Get the value of a JSON signed integer number. More...

ulonglong	get_uint () const
	Get the value of a JSON unsigned integer number. More...

void	get_datetime (MYSQL_TIME *t) const
	Get the value of a JSON date/time value. More...

bool	get_boolean () const
	Get a boolean value (a JSON true or false literal). More...

bool	seek (const Json_seekable_path &path, size_t legs, Json_wrapper_vector *hits, bool auto_wrap, bool only_need_one)
	Finds all of the json sub-documents which match the path expression. More...

size_t	length () const
	Compute the length of a document. More...

int	compare (const Json_wrapper &other, const CHARSET_INFO *cs=nullptr) const
	Compare this JSON value to another JSON value. More...

longlong	coerce_int (const char msgnam, enum_coercion_error cr_error, bool err, bool *unsigned_flag) const
	Extract an int (signed or unsigned) from the JSON if possible coercing if need be. More...

longlong	coerce_int (const char *msgnam) const
	Shorthand for coerce_int(msgnam, CE_WARNING, nullptr, nullptr). More...

double	coerce_real (const char msgnam, enum_coercion_error cr_error, bool err) const
	Extract a real from the JSON if possible, coercing if need be. More...

double	coerce_real (const char *msgnam) const
	Shorthand for coerce_real(msgnam, CE_WARNING, nullptr). More...

my_decimal *	coerce_decimal (my_decimal decimal_value, const char msgnam, enum_coercion_error cr_error, bool *err) const
	Extract a decimal from the JSON if possible, coercing if need be. More...

my_decimal *	coerce_decimal (my_decimal decimal_value, const char msgnam)
	Shorthand for coerce_decimal(decimal_value, msgnam, CE_WARNING, nullptr). More...

bool	coerce_date (MYSQL_TIME ltime, const char msgnam, enum_coercion_error cr_error=CE_WARNING, my_time_flags_t date_flags_arg=0) const
	Extract a date from the JSON if possible, coercing if need be. More...

bool	coerce_time (MYSQL_TIME ltime, const char msgnam, enum_coercion_error cr_error=CE_WARNING) const
	Extract a time value from the JSON if possible, coercing if need be. More...

size_t	make_sort_key (uchar *to, size_t length) const
	Make a sort key that can be used by filesort to order JSON values. More...

ulonglong	make_hash_key (ulonglong hash_val) const
	Make a hash key that can be used by sql_executor.cc/unique_hash in order to support SELECT DISTINCT. More...

bool	get_free_space (size_t *space) const
	Calculate the amount of unused space inside a JSON binary value. More...

bool	attempt_binary_update (const Field_json field, const Json_seekable_path &path, Json_wrapper new_value, bool replace, String result, bool partially_updated, bool *replaced_path)
	Attempt a binary partial update by replacing the value at path with new_value. More...

bool	binary_remove (const Field_json field, const Json_seekable_path &path, String result, bool *found_path)
	Remove a path from a binary JSON document. More...

void	sort (const CHARSET_INFO *cs=nullptr)
	Sort contents. More...

void	remove_duplicates (const CHARSET_INFO *cs=nullptr)
	Remove duplicate values. More...

Private Attributes
union {
struct {
Json_dom * m_value

bool m_alias
	If true, don't deallocate m_dom_value in destructor. More...

} m_dom
	The DOM representation, only used if m_is_dom is true. More...

json_binary::Value m_value
	The binary representation, only used if m_is_dom is false. More...

};

bool	m_is_dom
	Wraps a DOM iff true. More...

Detailed Description

Abstraction for accessing JSON values irrespective of whether they are (started out as) binary JSON values or JSON DOM values.

The purpose of this is to allow uniform access for callers. It allows us to access binary JSON values without necessarily building a DOM (and thus having to read the entire value unless necessary, e.g. for accessing only a single array slot or object field).

Instances of this class are usually created on the stack. In some cases instances are cached in an Item and reused, in which case they are allocated from query-duration memory (by allocating them on a MEM_ROOT).

Constructor & Destructor Documentation

◆ Json_wrapper() [1/6]

Json_wrapper::Json_wrapper ( )

inline

Create an empty wrapper.

Cf empty().

◆ Json_wrapper() [2/6]

Json_wrapper::Json_wrapper	(	Json_dom *	dom_value,
		bool	alias = `false`
	)

explicit

Wrap the supplied DOM value (no copy taken).

The wrapper takes ownership, unless alias is true or set_alias is called after construction. In the latter case the lifetime of the DOM is determined by the owner of the DOM, so clients need to ensure that that lifetime is sufficient, lest dead storage is attempted accessed.

Parameters

[in,out]	dom_value	the DOM value
	alias	Whether the wrapper is an alias to DOM

< no deallocation, make us empty

◆ Json_wrapper() [3/6]

Json_wrapper::Json_wrapper ( Json_dom_ptr dom_value )

inlineexplicit

Wrap the supplied DOM value.

The wrapper takes over the ownership.

◆ Json_wrapper() [4/6]

Json_wrapper::Json_wrapper ( const json_binary::Value & value )

explicit

Wrap a binary value.

Does not copy the underlying buffer, so lifetime is limited the that of the supplied value.

Parameters

[in] value the binary value

◆ Json_wrapper() [5/6]

Json_wrapper::Json_wrapper ( const Json_wrapper & old )

Copy constructor.

Does a deep copy of any owned DOM. If a DOM os not owned (aliased), the copy will also be aliased.

◆ Json_wrapper() [6/6]

Json_wrapper::Json_wrapper ( Json_wrapper && old )

noexcept

Move constructor.

Take over the ownership of the other wrapper's DOM, unless it's aliased. If the other wrapper is aliased, this wrapper becomes an alias too. Any already owned DOM will be deallocated.

Parameters

old	the wrapper whose contents to take over

◆ ~Json_wrapper()

Json_wrapper::~Json_wrapper ( )

Member Function Documentation

◆ attempt_binary_update()

bool Json_wrapper::attempt_binary_update	(	const Field_json *	field,
		const Json_seekable_path &	path,
		Json_wrapper *	new_value,
		bool	replace,
		String *	result,
		bool *	partially_updated,
		bool *	replaced_path
	)

Attempt a binary partial update by replacing the value at path with new_value.

On successful completion, the updated document will be available in result, and this Json_wrapper will point to result instead of the original binary representation. The modifications that have been applied, will also be collected as binary diffs, which can be retrieved via TABLE::get_binary_diffs().

Parameters

	field	the column being updated
	path	the path of the value to update
	new_value	the new value
	replace	true if we use JSON_REPLACE semantics
[in,out]	result	buffer that holds the updated JSON document (is empty if no partial update has been performed on this Json_wrapper so far, or contains the binary representation of the document in this wrapper otherwise)
[out]	partially_updated	gets set to true if partial update was successful, also if it was a no-op
[out]	replaced_path	gets set to true if the path was replaced, will be false if this update is a no-op

Return values

false	if the update was successful, or if it was determined that a full update was needed
true	if an error occurred

◆ binary_remove()

bool Json_wrapper::binary_remove	(	const Field_json *	field,
		const Json_seekable_path &	path,
		String *	result,
		bool *	found_path
	)

Remove a path from a binary JSON document.

On successful completion, the updated document will be available in result, and this Json_wrapper will point to result instead of the original binary representation. The modifications that have been applied, will also be collected as binary diffs, which can be retrieved via TABLE::get_binary_diffs().

Parameters

	field	the column being updated
	path	the path to remove from the document
[in,out]	result	buffer that holds the updated JSON document (is empty if no partial update has been performed on this Json_wrapper so far, or contains the binary representation of the document in this wrapper otherwise)
[out]	found_path	gets set to true if the path is found in the document, false otherwise

Return values

false	if the value was successfully updated
true	if an error occurred

◆ clone_dom()

Json_dom_ptr Json_wrapper::clone_dom ( ) const

Get the wrapped contents in DOM form.

Same as to_dom(), except it returns a clone of the original DOM instead of the actual, internal DOM tree.

Returns: pointer to a DOM object, or NULL if the DOM could not be allocated

◆ coerce_date()

bool Json_wrapper::coerce_date	(	MYSQL_TIME *	ltime,
		const char *	msgnam,
		enum_coercion_error	cr_error = `CE_WARNING`,
		my_time_flags_t	date_flags_arg = `0`
	)		const

Extract a date from the JSON if possible, coercing if need be.

Parameters

[in,out]	ltime	a value buffer
	msgnam	to use in error message if conversion failed
[in]	cr_error	Whether to raise an error or warning on data truncation
[in]	date_flags_arg	Flags to use for string -> date conversion

Returns: json value coerced to date

◆ coerce_decimal() [1/2]

my_decimal * Json_wrapper::coerce_decimal	(	my_decimal *	decimal_value,
		const char *	msgnam
	)

inline

Shorthand for coerce_decimal(decimal_value, msgnam, CE_WARNING, nullptr).

◆ coerce_decimal() [2/2]

my_decimal * Json_wrapper::coerce_decimal	(	my_decimal *	decimal_value,
		const char *	msgnam,
		enum_coercion_error	cr_error,
		bool *	err
	)		const

Extract a decimal from the JSON if possible, coercing if need be.

Parameters

[in,out]	decimal_value	a value buffer
[in]	msgnam	to use in error message if conversion failed
[in]	cr_error	Whether to raise an error or warning on data truncation
[out]	err	true <=> error occur during coercion

Returns: json value coerced to decimal

◆ coerce_int() [1/2]

longlong Json_wrapper::coerce_int ( const char * msgnam ) const

inline

Shorthand for coerce_int(msgnam, CE_WARNING, nullptr, nullptr).

◆ coerce_int() [2/2]

longlong Json_wrapper::coerce_int	(	const char *	msgnam,
		enum_coercion_error	cr_error,
		bool *	err,
		bool *	unsigned_flag
	)		const

Extract an int (signed or unsigned) from the JSON if possible coercing if need be.

Parameters

[in]	msgnam	to use in error message if conversion failed
[in]	cr_error	Whether to raise an error or warning on data truncation
[out]	err	true <=> error occur during coercion
[out]	unsigned_flag	Whether the value read from JSON data is unsigned

Returns: json value coerced to int

◆ coerce_real() [1/2]

double Json_wrapper::coerce_real ( const char * msgnam ) const

inline

Shorthand for coerce_real(msgnam, CE_WARNING, nullptr).

◆ coerce_real() [2/2]

double Json_wrapper::coerce_real	(	const char *	msgnam,
		enum_coercion_error	cr_error,
		bool *	err
	)		const

Extract a real from the JSON if possible, coercing if need be.

Parameters

[in]	msgnam	to use in error message if conversion failed
[in]	cr_error	Whether to raise an error or warning on data truncation
[out]	err	true <=> error occur during coercion

Returns: json value coerced to real

◆ coerce_time()

bool Json_wrapper::coerce_time	(	MYSQL_TIME *	ltime,
		const char *	msgnam,
		enum_coercion_error	cr_error = `CE_WARNING`
	)		const

Extract a time value from the JSON if possible, coercing if need be.

Parameters

[in,out]	ltime	a value buffer
	msgnam	to use in error message if conversion failed
[in]	cr_error	Whether to raise an error or warning on data truncation

Returns: json value coerced to time

◆ compare()

int Json_wrapper::compare	(	const Json_wrapper &	other,
		const CHARSET_INFO *	cs = `nullptr`
	)		const

Compare this JSON value to another JSON value.

Parameters

[in]	other	the other JSON value
[in]	cs	if given, this charset will be used in comparison of string values

Return values

-1	if this JSON value is less than the other JSON value
0	if the two JSON values are equal
1	if this JSON value is greater than the other JSON value

◆ dbug_print()

void Json_wrapper::dbug_print	(	const char *	message,
		const JsonDocumentDepthHandler &	depth_handler
	)		const

Print this JSON document to the debug trace.

Parameters

[in] message If given, the JSON document is prefixed with this message.

◆ empty()

bool Json_wrapper::empty ( ) const

inline

A Wrapper is defined to be empty if it is passed a NULL value with the constructor for JSON dom, or if the default constructor is used.

Returns: true if the wrapper is empty.

◆ field_type()

enum_field_types Json_wrapper::field_type ( ) const

Return the MYSQL type of the opaque value, see type().

Valid for J_OPAQUE. Calling this method if the type is not J_OPAQUE will give undefined results.

Returns: the type

◆ get_binary_value()

const json_binary::Value & Json_wrapper::get_binary_value ( ) const

inline

Gets the wrapped json_binary::Value object, if this wrapper holds a binary JSON value.

If is_dom() returns true, the result of calling this function is undefined.

◆ get_boolean()

bool Json_wrapper::get_boolean ( ) const

Get a boolean value (a JSON true or false literal).

Valid for J_BOOLEAN. Calling this method if the type is not J_BOOLEAN will give undefined results.

Returns: the value

◆ get_data()

const char * Json_wrapper::get_data ( ) const

Get a pointer to the data of a JSON string or JSON opaque value.

The data is still owner by the wrapper. The data may not be null terminated, so use in conjunction with get_data_length. Valid for J_STRING and J_OPAQUE. Calling this method if the type is not one of those will give undefined results.

Returns: the pointer

◆ get_data_length()

size_t Json_wrapper::get_data_length ( ) const

Get the length to the data of a JSON string or JSON opaque value.

Valid for J_STRING and J_OPAQUE. Calling this method if the type is not one of those will give undefined results.

Returns: the length

◆ get_datetime()

void Json_wrapper::get_datetime ( MYSQL_TIME * t ) const

Get the value of a JSON date/time value.

Valid for J_TIME, J_DATETIME, J_DATE and J_TIMESTAMP. Calling this method if the type is not one of those will give undefined results.

Parameters

[out] t the date/time value

◆ get_datetime_packed()

const char * Json_wrapper::get_datetime_packed ( char * buffer ) const

Get the wrapped datetime value in the packed format.

Parameters

[in,out] buffer a char buffer with space for at least Json_datetime::PACKED_SIZE characters

Returns: a char buffer that contains the packed representation of the datetime (may or may not be the same as buffer)

◆ get_decimal_data()

bool Json_wrapper::get_decimal_data ( my_decimal * d ) const

Get the MySQL representation of a JSON decimal value.

Valid for J_DECIMAL. Calling this method if the type is not J_DECIMAL will give undefined results.

Parameters

[out] d the decimal value

Returns: false on success, true on failure (which would indicate an internal error)

◆ get_dom()

const Json_dom * Json_wrapper::get_dom ( ) const

inline

Gets a pointer to the wrapped Json_dom object, if this wrapper holds a DOM.

If is_dom() returns false, the result of calling this function is undefined.

◆ get_double()

double Json_wrapper::get_double ( ) const

Get the value of a JSON double number.

Valid for J_DOUBLE. Calling this method if the type is not J_DOUBLE will give undefined results.

Returns: the value

◆ get_free_space()

bool Json_wrapper::get_free_space ( size_t * space ) const

Calculate the amount of unused space inside a JSON binary value.

Parameters

[out] space the amount of unused space, or zero if this is a DOM

Returns: false on success; true if the JSON binary value was invalid

◆ get_int()

longlong Json_wrapper::get_int ( ) const

Get the value of a JSON signed integer number.

Valid for J_INT. Calling this method if the type is not J_INT will give undefined results.

Returns: the value

◆ get_uint()

ulonglong Json_wrapper::get_uint ( ) const

Get the value of a JSON unsigned integer number.

Valid for J_UINT. Calling this method if the type is not J_UINT will give undefined results.

Returns: the value

◆ is_binary_backed_by()

bool Json_wrapper::is_binary_backed_by ( const String * str ) const

inline

Check if the wrapped JSON document is a binary value (a json_binary::Value), and if that binary is pointing to data stored in the given string.

This function can be used to check if overwriting the data in the string might overwrite and corrupt the document contained in this wrapper.

Parameters

str	a string which contains JSON binary data

Return values

true	if the string contains data that the wrapped document points to from its json_binary::Value representation
false	otherwise

◆ is_dom()

bool Json_wrapper::is_dom ( ) const

inline

Does this wrapper contain a DOM?

Return values

true	if the wrapper contains a DOM representation
false	if the wrapper contains a binary representation

◆ length()

size_t Json_wrapper::length ( ) const

Compute the length of a document.

This is the value which would be returned by the JSON_LENGTH() system function. So, this returns

for scalar values: 1
for objects: the number of members
for arrays: the number of cells

Returns: 1, the number of members, or the number of cells

◆ lookup()

Json_wrapper Json_wrapper::lookup ( const MYSQL_LEX_CSTRING & key ) const

If this wrapper holds a JSON object, get the value corresponding to the member key.

Valid for J_OBJECT. Calling this method if the type is not J_OBJECT will give undefined results.

Parameters

[in] key name for identifying member

Returns: The member value. If there is no member with the specified name, a value with type Json_dom::J_ERROR is returned.

◆ make_hash_key()

ulonglong Json_wrapper::make_hash_key ( ulonglong hash_val ) const

Make a hash key that can be used by sql_executor.cc/unique_hash in order to support SELECT DISTINCT.

Parameters

[in] hash_val An initial hash value.

◆ make_sort_key()

size_t Json_wrapper::make_sort_key	(	uchar *	to,
		size_t	length
	)		const

Make a sort key that can be used by filesort to order JSON values.

Parameters

[out]	to	a buffer to which the sort key is written
[in]	length	the length of the sort key

Key storage format is following:

  |<json type><   sort key    >|
   1 byte    / variable length /

JSON is assumed to be non-sql-null and valid (checked by caller). Key length contains full length - the len prefix itself, json type and the sort key. All numeric types are stored as a number, without distinction to double/decimal/int/etc. See make_json_numeric_sort_key(). Same is done to DATETIME and TIMESTAMP types. For string and opaque types only the prefix that fits into the output buffer is stored. For JSON objects and arrays only their length (number of elements) is stored, this is a limitation of current implementation.

◆ operator=() [1/2]

Json_wrapper & Json_wrapper::operator= ( const Json_wrapper & old )

Assignment operator.

Does a deep copy of any owned DOM. If a DOM os not owned (aliased), the copy will also be aliased. Any owned DOM in the left side will be deallocated.

◆ operator=() [2/2]

Json_wrapper & Json_wrapper::operator= ( Json_wrapper && old )

noexcept

Move-assignment operator.

Take over the ownership of the other wrapper's DOM, unless it's aliased. If the other wrapper is aliased, this wrapper becomes an alias too. Any already owned DOM will be deallocated.

Parameters

old	the wrapper whose contents to take over

◆ operator[]()

Json_wrapper Json_wrapper::operator[] ( size_t index ) const

If this wrapper holds a JSON array, get an array value by indexing into the array.

Valid for J_ARRAY. Calling this method if the type is not J_ARRAY will give undefined results.

Returns: the array value

◆ remove_duplicates()

void Json_wrapper::remove_duplicates ( const CHARSET_INFO * cs = nullptr )

Remove duplicate values.

Applicable to JSON arrays only, array will be sorted.

◆ seek()

bool Json_wrapper::seek	(	const Json_seekable_path &	path,
		size_t	legs,
		Json_wrapper_vector *	hits,
		bool	auto_wrap,
		bool	only_need_one
	)

Finds all of the json sub-documents which match the path expression.

Puts the matches on an evolving vector of results. This is a bit inefficient for binary wrappers because you can't build up a binary array incrementally from its cells. Instead, you have to turn each cell into a dom and then add the doms to a dom array.

Calling this if empty() returns true is an error.

Special care must be taken when the path expression contains more than one ellipsis (**) token. That is because multiple paths with ellipses may identify the same value. Consider the following document:

{ "a": { "x" : { "b": { "y": { "b": { "z": { "c": 100 } } } } } } }

The innermost value (the number 100) has the following unique, non-wildcarded address:

$.a.x.b.y.b.z.c

That location is reached by both of the following paths which include the ellipsis token:

$.a.x.b**.c
$.a.x.b.y.b**.c

And those addresses both satisfy the following path expression which has two ellipses:

$.a**.b**.c

In this case, we only want to return one instance of $.a.x.b.y.b.z.c

Similarly, special care must be taken if an auto-wrapping array path leg follows an ellipsis. Consider the following document:

{ "a": { "b" : [ 1, 2, 3 ] } }

The first element of the array (the number 1) can be reached with either of these two non-wildcarded addresses, due to array auto-wrapping:

$.a.b[0]
$.a.b[0][0]

Both of those addresses match the following path expression, which has an ellipsis followed by an auto-wrapping path leg:

$**[0]

Parameters

[in]	path	the (possibly wildcarded) address of the sub-documents
[in]	legs	the number of legs to use from path
[out]	hits	the result of the search
[in]	auto_wrap	true of we match a final scalar with search for [0]
[in]	only_need_one	True if we can stop after finding one match

Return values

false	on success
true	on error

◆ set_alias()

void Json_wrapper::set_alias ( )

inline

Only meaningful iff the wrapper encapsulates a DOM.

Marks the wrapper as not owning the DOM object, i.e. it will not be deallocated in the wrapper's destructor. Useful if one wants a wrapper around a DOM owned by someone else.

◆ sort()

void Json_wrapper::sort ( const CHARSET_INFO * cs = nullptr )

Sort contents.

Applicable to JSON arrays only.

◆ to_binary()

bool Json_wrapper::to_binary	(	const THD *	thd,
		String *	str
	)		const

Get the wrapped contents in binary value form.

Parameters

[in]	thd	current session
[in,out]	str	a string that will be filled with the binary value

Return values

false	on success
true	on error

◆ to_dom()

Json_dom * Json_wrapper::to_dom ( )

Get the wrapped contents in DOM form.

The DOM is (still) owned by the wrapper. If this wrapper originally held a value, it is now converted to hold (and eventually release) the DOM version.

Returns: pointer to a DOM object, or NULL if the DOM could not be allocated

◆ to_pretty_string()

bool Json_wrapper::to_pretty_string	(	String *	buffer,
		const char *	func_name,
		const JsonDocumentDepthHandler &	depth_handler
	)		const

Format the JSON value to an external JSON string in buffer in the format of ISO/IEC 10646.

Add newlines and indentation for readability.

Parameters

[in,out]	buffer	the buffer that receives the formatted string (the string is appended, so make sure the length is set correctly before calling)
[in]	func_name	the name of the calling function

Return values

false	on success
true	on error

◆ to_string()

bool Json_wrapper::to_string	(	String *	buffer,
		bool	json_quoted,
		const char *	func_name,
		const JsonDocumentDepthHandler &	depth_handler
	)		const

Format the JSON value to an external JSON string in buffer in the format of ISO/IEC 10646.

Parameters

[in,out]	buffer	the formatted string is appended, so make sure the length is set correctly before calling
[in]	json_quoted	if the JSON value is a string and json_quoted is false, don't perform quoting on the string. This is only used by JSON_UNQUOTE.
[in]	func_name	The name of the function that called to_string().

Returns: false formatting went well, else true

◆ type()

enum_json_type Json_wrapper::type ( ) const

Return the type of the wrapped JSON value.

Returns: the type, or Json_dom::J_ERROR if the wrapper does not contain a JSON value

Member Data Documentation

◆

union { ... } Json_wrapper::@34

◆ m_alias

bool Json_wrapper::m_alias

If true, don't deallocate m_dom_value in destructor.

◆

struct { ... } Json_wrapper::m_dom

The DOM representation, only used if m_is_dom is true.

◆ m_is_dom

bool Json_wrapper::m_is_dom

private

Wraps a DOM iff true.

◆ m_value [1/2]

Json_dom* Json_wrapper::m_value

◆ m_value [2/2]

json_binary::Value Json_wrapper::m_value

The binary representation, only used if m_is_dom is false.

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

sql-common/json_dom.h
sql-common/json_dom.cc

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Json_wrapper() [1/6]

◆ Json_wrapper() [2/6]

◆ Json_wrapper() [3/6]

◆ Json_wrapper() [4/6]

◆ Json_wrapper() [5/6]

◆ Json_wrapper() [6/6]

◆ ~Json_wrapper()

Member Function Documentation

◆ attempt_binary_update()

◆ binary_remove()

◆ clone_dom()

◆ coerce_date()

◆ coerce_decimal() [1/2]

◆ coerce_decimal() [2/2]

◆ coerce_int() [1/2]

◆ coerce_int() [2/2]

◆ coerce_real() [1/2]

◆ coerce_real() [2/2]

◆ coerce_time()

◆ compare()

◆ dbug_print()

◆ empty()

◆ field_type()

◆ get_binary_value()

◆ get_boolean()

◆ get_data()

◆ get_data_length()

◆ get_datetime()

◆ get_datetime_packed()

◆ get_decimal_data()

◆ get_dom()

◆ get_double()

◆ get_free_space()

◆ get_int()

◆ get_uint()

◆ is_binary_backed_by()

◆ is_dom()

◆ length()

◆ lookup()

◆ make_hash_key()

◆ make_sort_key()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator[]()

◆ remove_duplicates()

◆ seek()

◆ set_alias()

◆ sort()

◆ to_binary()

◆ to_dom()

◆ to_pretty_string()

◆ to_string()

◆ type()

Member Data Documentation

◆

◆ m_alias

◆

◆ m_is_dom

◆ m_value [1/2]

◆ m_value [2/2]