996 lines
30 KiB
C
996 lines
30 KiB
C
/**
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* JSON Simple/Stacked/Stateful Lexer.
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* - Does not buffer data
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* - Maintains state
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* - Callback oriented
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* - Lightweight and fast. One source file and one header file
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*
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* Copyright (C) 2012-2015 Mark Nunberg
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* See included LICENSE file for license details.
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*/
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#ifndef JSONSL_H_
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#define JSONSL_H_
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#include <stdio.h>
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#include <stdlib.h>
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#include <stddef.h>
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#include <string.h>
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#include <sys/types.h>
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#include <wchar.h>
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#ifdef __cplusplus
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extern "C" {
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#endif /* __cplusplus */
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#ifdef JSONSL_USE_WCHAR
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typedef jsonsl_char_t wchar_t;
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typedef jsonsl_uchar_t unsigned wchar_t;
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#else
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typedef char jsonsl_char_t;
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typedef unsigned char jsonsl_uchar_t;
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#endif /* JSONSL_USE_WCHAR */
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/* Stolen from http-parser.h, and possibly others */
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#if defined(_WIN32) && !defined(__MINGW32__) && (!defined(_MSC_VER) || _MSC_VER<1600)
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typedef __int8 int8_t;
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typedef unsigned __int8 uint8_t;
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typedef __int16 int16_t;
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typedef unsigned __int16 uint16_t;
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typedef __int32 int32_t;
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typedef unsigned __int32 uint32_t;
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typedef __int64 int64_t;
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typedef unsigned __int64 uint64_t;
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#if !defined(_MSC_VER) || _MSC_VER<1400
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typedef unsigned int size_t;
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typedef int ssize_t;
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#endif
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#else
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#include <stdint.h>
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#endif
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#if (!defined(JSONSL_STATE_GENERIC)) && (!defined(JSONSL_STATE_USER_FIELDS))
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#define JSONSL_STATE_GENERIC
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#endif /* !defined JSONSL_STATE_GENERIC */
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#ifdef JSONSL_STATE_GENERIC
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#define JSONSL_STATE_USER_FIELDS
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#endif /* JSONSL_STATE_GENERIC */
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/* Additional fields for component object */
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#ifndef JSONSL_JPR_COMPONENT_USER_FIELDS
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#define JSONSL_JPR_COMPONENT_USER_FIELDS
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#endif
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#ifndef JSONSL_API
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/**
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* We require a /DJSONSL_DLL so that users already using this as a static
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* or embedded library don't get confused
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*/
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#if defined(_WIN32) && defined(JSONSL_DLL)
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#define JSONSL_API __declspec(dllexport)
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#else
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#define JSONSL_API
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#endif /* _WIN32 */
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#endif /* !JSONSL_API */
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#ifndef JSONSL_INLINE
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#if defined(_MSC_VER)
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#define JSONSL_INLINE __inline
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#elif defined(__GNUC__)
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#define JSONSL_INLINE __inline__
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#else
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#define JSONSL_INLINE inline
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#endif /* _MSC_VER or __GNUC__ */
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#endif /* JSONSL_INLINE */
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#define JSONSL_MAX_LEVELS 512
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struct jsonsl_st;
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typedef struct jsonsl_st *jsonsl_t;
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typedef struct jsonsl_jpr_st* jsonsl_jpr_t;
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/**
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* This flag is true when AND'd against a type whose value
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* must be in "quoutes" i.e. T_HKEY and T_STRING
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*/
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#define JSONSL_Tf_STRINGY 0xffff00
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/**
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* Constant representing the special JSON types.
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* The values are special and aid in speed (the OBJECT and LIST
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* values are the char literals of their openings).
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*
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* Their actual value is a character which attempts to resemble
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* some mnemonic reference to the actual type.
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*
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* If new types are added, they must fit into the ASCII printable
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* range (so they should be AND'd with 0x7f and yield something
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* meaningful)
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*/
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#define JSONSL_XTYPE \
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X(STRING, '"'|JSONSL_Tf_STRINGY) \
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X(HKEY, '#'|JSONSL_Tf_STRINGY) \
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X(OBJECT, '{') \
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X(LIST, '[') \
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X(SPECIAL, '^') \
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X(UESCAPE, 'u')
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typedef enum {
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#define X(o, c) \
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JSONSL_T_##o = c,
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JSONSL_XTYPE
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JSONSL_T_UNKNOWN = '?',
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/* Abstract 'root' object */
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JSONSL_T_ROOT = 0
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#undef X
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} jsonsl_type_t;
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/**
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* Subtypes for T_SPECIAL. We define them as flags
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* because more than one type can be applied to a
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* given object.
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*/
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#define JSONSL_XSPECIAL \
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X(NONE, 0) \
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X(SIGNED, 1<<0) \
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X(UNSIGNED, 1<<1) \
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X(TRUE, 1<<2) \
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X(FALSE, 1<<3) \
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X(NULL, 1<<4) \
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X(FLOAT, 1<<5) \
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X(EXPONENT, 1<<6) \
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X(NONASCII, 1<<7)
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typedef enum {
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#define X(o,b) \
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JSONSL_SPECIALf_##o = b,
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JSONSL_XSPECIAL
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#undef X
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/* Handy flags for checking */
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JSONSL_SPECIALf_UNKNOWN = 1 << 8,
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/** @private Private */
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JSONSL_SPECIALf_ZERO = 1 << 9 | JSONSL_SPECIALf_UNSIGNED,
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/** @private */
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JSONSL_SPECIALf_DASH = 1 << 10,
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/** Type is numeric */
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JSONSL_SPECIALf_NUMERIC = (JSONSL_SPECIALf_SIGNED| JSONSL_SPECIALf_UNSIGNED),
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/** Type is a boolean */
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JSONSL_SPECIALf_BOOLEAN = (JSONSL_SPECIALf_TRUE|JSONSL_SPECIALf_FALSE),
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/** Type is an "extended", not integral type (but numeric) */
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JSONSL_SPECIALf_NUMNOINT = (JSONSL_SPECIALf_FLOAT|JSONSL_SPECIALf_EXPONENT)
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} jsonsl_special_t;
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/**
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* These are the various types of stack (or other) events
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* which will trigger a callback.
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* Like the type constants, this are also mnemonic
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*/
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#define JSONSL_XACTION \
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X(PUSH, '+') \
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X(POP, '-') \
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X(UESCAPE, 'U') \
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X(ERROR, '!')
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typedef enum {
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#define X(a,c) \
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JSONSL_ACTION_##a = c,
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JSONSL_XACTION
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JSONSL_ACTION_UNKNOWN = '?'
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#undef X
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} jsonsl_action_t;
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/**
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* Various errors which may be thrown while parsing JSON
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*/
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#define JSONSL_XERR \
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/* Trailing garbage characters */ \
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X(GARBAGE_TRAILING) \
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/* We were expecting a 'special' (numeric, true, false, null) */ \
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X(SPECIAL_EXPECTED) \
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/* The 'special' value was incomplete */ \
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X(SPECIAL_INCOMPLETE) \
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/* Found a stray token */ \
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X(STRAY_TOKEN) \
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/* We were expecting a token before this one */ \
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X(MISSING_TOKEN) \
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/* Cannot insert because the container is not ready */ \
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X(CANT_INSERT) \
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/* Found a '\' outside a string */ \
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X(ESCAPE_OUTSIDE_STRING) \
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/* Found a ':' outside of a hash */ \
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X(KEY_OUTSIDE_OBJECT) \
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/* found a string outside of a container */ \
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X(STRING_OUTSIDE_CONTAINER) \
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/* Found a null byte in middle of string */ \
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X(FOUND_NULL_BYTE) \
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/* Current level exceeds limit specified in constructor */ \
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X(LEVELS_EXCEEDED) \
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/* Got a } as a result of an opening [ or vice versa */ \
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X(BRACKET_MISMATCH) \
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/* We expected a key, but got something else instead */ \
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X(HKEY_EXPECTED) \
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/* We got an illegal control character (bad whitespace or something) */ \
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X(WEIRD_WHITESPACE) \
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/* Found a \u-escape, but there were less than 4 following hex digits */ \
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X(UESCAPE_TOOSHORT) \
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/* Invalid two-character escape */ \
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X(ESCAPE_INVALID) \
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/* Trailing comma */ \
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X(TRAILING_COMMA) \
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/* An invalid number was passed in a numeric field */ \
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X(INVALID_NUMBER) \
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/* Value is missing for object */ \
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X(VALUE_EXPECTED) \
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/* The following are for JPR Stuff */ \
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\
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/* Found a literal '%' but it was only followed by a single valid hex digit */ \
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X(PERCENT_BADHEX) \
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/* jsonpointer URI is malformed '/' */ \
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X(JPR_BADPATH) \
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/* Duplicate slash */ \
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X(JPR_DUPSLASH) \
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/* No leading root */ \
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X(JPR_NOROOT) \
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/* Allocation failure */ \
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X(ENOMEM) \
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/* Invalid unicode codepoint detected (in case of escapes) */ \
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X(INVALID_CODEPOINT)
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typedef enum {
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JSONSL_ERROR_SUCCESS = 0,
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#define X(e) \
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JSONSL_ERROR_##e,
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JSONSL_XERR
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#undef X
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JSONSL_ERROR_GENERIC
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} jsonsl_error_t;
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/**
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* A state is a single level of the stack.
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* Non-private data (i.e. the 'data' field, see the STATE_GENERIC section)
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* will remain in tact until the item is popped.
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*
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* As a result, it means a parent state object may be accessed from a child
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* object, (the parents fields will all be valid). This allows a user to create
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* an ad-hoc hierarchy on top of the JSON one.
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*
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*/
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struct jsonsl_state_st {
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/**
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* The JSON object type
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*/
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unsigned int type;
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/**
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* The position (in terms of number of bytes since the first call to
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* jsonsl_feed()) at which the state was first pushed. This includes
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* opening tokens, if applicable.
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*
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* @note For strings (i.e. type & JSONSL_Tf_STRINGY is nonzero) this will
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* be the position of the first quote.
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*
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* @see jsonsl_st::pos which contains the _current_ position and can be
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* used during a POP callback to get the length of the element.
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*/
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size_t pos_begin;
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/**FIXME: This is redundant as the same information can be derived from
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* jsonsl_st::pos at pop-time */
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size_t pos_cur;
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/** If this element is special, then its extended type is here */
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unsigned short special_flags;
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/**
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* Level of recursion into nesting. This is mainly a convenience
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* variable, as this can technically be deduced from the lexer's
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* level parameter (though the logic is not that simple)
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*/
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unsigned short level;
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/**
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* how many elements in the object/list.
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* For objects (hashes), an element is either
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* a key or a value. Thus for one complete pair,
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* nelem will be 2.
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*
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* For special types, this will hold the sum of the digits.
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* This only holds true for values which are simple signed/unsigned
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* numbers. Otherwise a special flag is set, and extra handling is not
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* performed.
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*/
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uint32_t nelem;
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/*TODO: merge this and special_flags into a union */
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/**
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* Useful for an opening nest, this will prevent a callback from being
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* invoked on this item or any of its children
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*/
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int ignore_callback : 1;
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/**
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* Counter which is incremented each time an escape ('\') is encountered.
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* This is used internally for non-string types and should only be
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* inspected by the user if the state actually represents a string
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* type.
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*/
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unsigned int nescapes : 31;
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/**
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* Put anything you want here. if JSONSL_STATE_USER_FIELDS is here, then
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* the macro expansion happens here.
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*
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* You can use these fields to store hierarchical or 'tagging' information
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* for specific objects.
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*
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* See the documentation above for the lifetime of the state object (i.e.
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* if the private data points to allocated memory, it should be freed
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* when the object is popped, as the state object will be re-used)
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*/
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#ifndef JSONSL_STATE_GENERIC
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JSONSL_STATE_USER_FIELDS
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#else
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/**
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* Otherwise, this is a simple void * pointer for anything you want
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*/
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void *data;
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#endif /* JSONSL_STATE_USER_FIELDS */
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};
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/**Gets the number of elements in the list.
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* @param st The state. Must be of type JSONSL_T_LIST
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* @return number of elements in the list
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*/
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#define JSONSL_LIST_SIZE(st) ((st)->nelem)
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/**Gets the number of key-value pairs in an object
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* @param st The state. Must be of type JSONSL_T_OBJECT
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* @return the number of key-value pairs in the object
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*/
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#define JSONSL_OBJECT_SIZE(st) ((st)->nelem / 2)
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/**Gets the numeric value.
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* @param st The state. Must be of type JSONSL_T_SPECIAL and
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* special_flags must have the JSONSL_SPECIALf_NUMERIC flag
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* set.
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* @return the numeric value of the state.
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*/
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#define JSONSL_NUMERIC_VALUE(st) ((st)->nelem)
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/*
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* So now we need some special structure for keeping the
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* JPR info in sync. Preferrably all in a single block
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* of memory (there's no need for separate allocations.
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* So we will define a 'table' with the following layout
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*
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* Level nPosbl JPR1_last JPR2_last JPR3_last
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*
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* 0 1 NOMATCH POSSIBLE POSSIBLE
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* 1 0 NOMATCH NOMATCH COMPLETE
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* [ table ends here because no further path is possible]
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*
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* Where the JPR..n corresponds to the number of JPRs
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* requested, and nPosble is a quick flag to determine
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*
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* the number of possibilities. In the future this might
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* be made into a proper 'jump' table,
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*
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* Since we always mark JPRs from the higher levels descending
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* into the lower ones, a prospective child match would first
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* look at the parent table to check the possibilities, and then
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* see which ones were possible..
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*
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* Thus, the size of this blob would be (and these are all ints here)
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* nLevels * nJPR * 2.
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*
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* the 'Width' of the table would be nJPR*2, and the 'height' would be
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* nlevels
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*/
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/**
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* This is called when a stack change ocurs.
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*
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* @param jsn The lexer
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* @param action The type of action, this can be PUSH or POP
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* @param state A pointer to the stack currently affected by the action
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* @param at A pointer to the position of the input buffer which triggered
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* this action.
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*/
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typedef void (*jsonsl_stack_callback)(
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jsonsl_t jsn,
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jsonsl_action_t action,
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struct jsonsl_state_st* state,
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const jsonsl_char_t *at);
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/**
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* This is called when an error is encountered.
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* Sometimes it's possible to 'erase' characters (by replacing them
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* with whitespace). If you think you have corrected the error, you
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* can return a true value, in which case the parser will backtrack
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* and try again.
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*
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* @param jsn The lexer
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* @param error The error which was thrown
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* @param state the current state
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* @param a pointer to the position of the input buffer which triggered
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* the error. Note that this is not const, this is because you have the
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* possibility of modifying the character in an attempt to correct the
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* error
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*
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* @return zero to bail, nonzero to try again (this only makes sense if
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* the input buffer has been modified by this callback)
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*/
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typedef int (*jsonsl_error_callback)(
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jsonsl_t jsn,
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jsonsl_error_t error,
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struct jsonsl_state_st* state,
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jsonsl_char_t *at);
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struct jsonsl_st {
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/** Public, read-only */
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/** This is the current level of the stack */
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unsigned int level;
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/** Flag set to indicate we should stop processing */
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unsigned int stopfl;
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/**
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* This is the current position, relative to the beginning
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* of the stream.
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*/
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size_t pos;
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/** This is the 'bytes' variable passed to feed() */
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const jsonsl_char_t *base;
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/** Callback invoked for PUSH actions */
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jsonsl_stack_callback action_callback_PUSH;
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/** Callback invoked for POP actions */
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jsonsl_stack_callback action_callback_POP;
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/** Default callback for any action, if neither PUSH or POP callbacks are defined */
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jsonsl_stack_callback action_callback;
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/**
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* Do not invoke callbacks for objects deeper than this level.
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* NOTE: This field establishes the lower bound for ignored callbacks,
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* and is thus misnamed. `min_ignore_level` would actually make more
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* sense, but we don't want to break API.
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*/
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unsigned int max_callback_level;
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/** The error callback. Invoked when an error happens. Should not be NULL */
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jsonsl_error_callback error_callback;
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/* these are boolean flags you can modify. You will be called
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* about notification for each of these types if the corresponding
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* variable is true.
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*/
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/**
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* @name Callback Booleans.
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* These determine whether a callback is to be invoked for certain types of objects
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* @{*/
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/** Boolean flag to enable or disable the invokcation for events on this type*/
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int call_SPECIAL;
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int call_OBJECT;
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int call_LIST;
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int call_STRING;
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int call_HKEY;
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/*@}*/
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/**
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* @name u-Escape handling
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* Special handling for the \\u-f00d type sequences. These are meant
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* to be translated back into the corresponding octet(s).
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* A special callback (if set) is invoked with *at=='u'. An application
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* may wish to temporarily suspend parsing and handle the 'u-' sequence
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* internally (or not).
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*/
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/*@{*/
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/** Callback to be invoked for a u-escape */
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jsonsl_stack_callback action_callback_UESCAPE;
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/** Boolean flag, whether to invoke the callback */
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int call_UESCAPE;
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/** Boolean flag, whether we should return after encountering a u-escape:
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* the callback is invoked and then we return if this is true
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*/
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int return_UESCAPE;
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/*@}*/
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struct {
|
|
int allow_trailing_comma;
|
|
} options;
|
|
|
|
/** Put anything here */
|
|
void *data;
|
|
|
|
/*@{*/
|
|
/** Private */
|
|
int in_escape;
|
|
char expecting;
|
|
char tok_last;
|
|
int can_insert;
|
|
unsigned int levels_max;
|
|
|
|
#ifndef JSONSL_NO_JPR
|
|
size_t jpr_count;
|
|
jsonsl_jpr_t *jprs;
|
|
|
|
/* Root pointer for JPR matching information */
|
|
size_t *jpr_root;
|
|
#endif /* JSONSL_NO_JPR */
|
|
/*@}*/
|
|
|
|
/**
|
|
* This is the stack. Its upper bound is levels_max, or the
|
|
* nlevels argument passed to jsonsl_new. If you modify this structure,
|
|
* make sure that this member is last.
|
|
*/
|
|
struct jsonsl_state_st stack[1];
|
|
};
|
|
|
|
|
|
/**
|
|
* Creates a new lexer object, with capacity for recursion up to nlevels
|
|
*
|
|
* @param nlevels maximum recursion depth
|
|
*/
|
|
JSONSL_API
|
|
jsonsl_t jsonsl_new(int nlevels);
|
|
|
|
JSONSL_API
|
|
jsonsl_t jsonsl_init(jsonsl_t jsn, int nlevels);
|
|
|
|
JSONSL_API
|
|
size_t jsonsl_get_size(int nlevels);
|
|
|
|
/**
|
|
* Feeds data into the lexer.
|
|
*
|
|
* @param jsn the lexer object
|
|
* @param bytes new data to be fed
|
|
* @param nbytes size of new data
|
|
*/
|
|
JSONSL_API
|
|
void jsonsl_feed(jsonsl_t jsn, const jsonsl_char_t *bytes, size_t nbytes);
|
|
|
|
/**
|
|
* Resets the internal parser state. This does not free the parser
|
|
* but does clean it internally, so that the next time feed() is called,
|
|
* it will be treated as a new stream
|
|
*
|
|
* @param jsn the lexer
|
|
*/
|
|
JSONSL_API
|
|
void jsonsl_reset(jsonsl_t jsn);
|
|
|
|
/**
|
|
* Frees the lexer, cleaning any allocated memory taken
|
|
*
|
|
* @param jsn the lexer
|
|
*/
|
|
JSONSL_API
|
|
void jsonsl_destroy(jsonsl_t jsn);
|
|
|
|
/**
|
|
* Gets the 'parent' element, given the current one
|
|
*
|
|
* @param jsn the lexer
|
|
* @param cur the current nest, which should be a struct jsonsl_nest_st
|
|
*/
|
|
static JSONSL_INLINE
|
|
struct jsonsl_state_st *jsonsl_last_state(const jsonsl_t jsn,
|
|
const struct jsonsl_state_st *state)
|
|
{
|
|
/* Don't complain about overriding array bounds */
|
|
if (state->level > 1) {
|
|
return jsn->stack + state->level - 1;
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Gets the state of the last fully consumed child of this parent. This is
|
|
* only valid in the parent's POP callback.
|
|
*
|
|
* @param the lexer
|
|
* @return A pointer to the child.
|
|
*/
|
|
static JSONSL_INLINE
|
|
struct jsonsl_state_st *jsonsl_last_child(const jsonsl_t jsn,
|
|
const struct jsonsl_state_st *parent)
|
|
{
|
|
return jsn->stack + (parent->level + 1);
|
|
}
|
|
|
|
/**Call to instruct the parser to stop parsing and return. This is valid
|
|
* only from within a callback */
|
|
static JSONSL_INLINE
|
|
void jsonsl_stop(jsonsl_t jsn)
|
|
{
|
|
jsn->stopfl = 1;
|
|
}
|
|
|
|
/**
|
|
* This enables receiving callbacks on all events. Doesn't do
|
|
* anything special but helps avoid some boilerplate.
|
|
* This does not touch the UESCAPE callbacks or flags.
|
|
*/
|
|
static JSONSL_INLINE
|
|
void jsonsl_enable_all_callbacks(jsonsl_t jsn)
|
|
{
|
|
jsn->call_HKEY = 1;
|
|
jsn->call_STRING = 1;
|
|
jsn->call_OBJECT = 1;
|
|
jsn->call_SPECIAL = 1;
|
|
jsn->call_LIST = 1;
|
|
}
|
|
|
|
/**
|
|
* A macro which returns true if the current state object can
|
|
* have children. This means a list type or an object type.
|
|
*/
|
|
#define JSONSL_STATE_IS_CONTAINER(state) \
|
|
(state->type == JSONSL_T_OBJECT || state->type == JSONSL_T_LIST)
|
|
|
|
/**
|
|
* These two functions, dump a string representation
|
|
* of the error or type, respectively. They will never
|
|
* return NULL
|
|
*/
|
|
JSONSL_API
|
|
const char* jsonsl_strerror(jsonsl_error_t err);
|
|
JSONSL_API
|
|
const char* jsonsl_strtype(jsonsl_type_t jt);
|
|
|
|
/**
|
|
* Dumps global metrics to the screen. This is a noop unless
|
|
* jsonsl was compiled with JSONSL_USE_METRICS
|
|
*/
|
|
JSONSL_API
|
|
void jsonsl_dump_global_metrics(void);
|
|
|
|
/* This macro just here for editors to do code folding */
|
|
#ifndef JSONSL_NO_JPR
|
|
|
|
/**
|
|
* @name JSON Pointer API
|
|
*
|
|
* JSONPointer API. This isn't really related to the lexer (at least not yet)
|
|
* JSONPointer provides an extremely simple specification for providing
|
|
* locations within JSON objects. We will extend it a bit and allow for
|
|
* providing 'wildcard' characters by which to be able to 'query' the stream.
|
|
*
|
|
* See http://tools.ietf.org/html/draft-pbryan-zyp-json-pointer-00
|
|
*
|
|
* Currently I'm implementing the 'single query' API which can only use a single
|
|
* query component. In the future I will integrate my yet-to-be-published
|
|
* Boyer-Moore-esque prefix searching implementation, in order to allow
|
|
* multiple paths to be merged into one for quick and efficient searching.
|
|
*
|
|
*
|
|
* JPR (as we'll refer to it within the source) can be used by splitting
|
|
* the components into mutliple sections, and incrementally 'track' each
|
|
* component. When JSONSL delivers a 'pop' callback for a string, or a 'push'
|
|
* callback for an object, we will check to see whether the index matching
|
|
* the component corresponding to the current level contains a match
|
|
* for our path.
|
|
*
|
|
* In order to do this properly, a structure must be maintained within the
|
|
* parent indicating whether its children are possible matches. This flag
|
|
* will be 'inherited' by call children which may conform to the match
|
|
* specification, and discarded by all which do not (thereby eliminating
|
|
* their children from inheriting it).
|
|
*
|
|
* A successful match is a complete one. One can provide multiple paths with
|
|
* multiple levels of matches e.g.
|
|
* /foo/bar/baz/^/blah
|
|
*
|
|
* @{
|
|
*/
|
|
|
|
/** The wildcard character */
|
|
#ifndef JSONSL_PATH_WILDCARD_CHAR
|
|
#define JSONSL_PATH_WILDCARD_CHAR '^'
|
|
#endif /* WILDCARD_CHAR */
|
|
|
|
#define JSONSL_XMATCH \
|
|
X(COMPLETE,1) \
|
|
X(POSSIBLE,0) \
|
|
X(NOMATCH,-1) \
|
|
X(TYPE_MISMATCH, -2)
|
|
|
|
typedef enum {
|
|
|
|
#define X(T,v) \
|
|
JSONSL_MATCH_##T = v,
|
|
JSONSL_XMATCH
|
|
|
|
#undef X
|
|
JSONSL_MATCH_UNKNOWN
|
|
} jsonsl_jpr_match_t;
|
|
|
|
typedef enum {
|
|
JSONSL_PATH_STRING = 1,
|
|
JSONSL_PATH_WILDCARD,
|
|
JSONSL_PATH_NUMERIC,
|
|
JSONSL_PATH_ROOT,
|
|
|
|
/* Special */
|
|
JSONSL_PATH_INVALID = -1,
|
|
JSONSL_PATH_NONE = 0
|
|
} jsonsl_jpr_type_t;
|
|
|
|
struct jsonsl_jpr_component_st {
|
|
/** The string the component points to */
|
|
char *pstr;
|
|
/** if this is a numeric type, the number is 'cached' here */
|
|
unsigned long idx;
|
|
/** The length of the string */
|
|
size_t len;
|
|
/** The type of component (NUMERIC or STRING) */
|
|
jsonsl_jpr_type_t ptype;
|
|
|
|
/** Set this to true to enforce type checking between dict keys and array
|
|
* indices. jsonsl_jpr_match() will return TYPE_MISMATCH if it detects
|
|
* that an array index is actually a child of a dictionary. */
|
|
short is_arridx;
|
|
|
|
/* Extra fields (for more advanced searches. Default is empty) */
|
|
JSONSL_JPR_COMPONENT_USER_FIELDS
|
|
};
|
|
|
|
struct jsonsl_jpr_st {
|
|
/** Path components */
|
|
struct jsonsl_jpr_component_st *components;
|
|
size_t ncomponents;
|
|
|
|
/**Type of the match to be expected. If nonzero, will be compared against
|
|
* the actual type */
|
|
unsigned match_type;
|
|
|
|
/** Base of allocated string for components */
|
|
char *basestr;
|
|
|
|
/** The original match string. Useful for returning to the user */
|
|
char *orig;
|
|
size_t norig;
|
|
};
|
|
|
|
/**
|
|
* Create a new JPR object.
|
|
*
|
|
* @param path the JSONPointer path specification.
|
|
* @param errp a pointer to a jsonsl_error_t. If this function returns NULL,
|
|
* then more details will be in this variable.
|
|
*
|
|
* @return a new jsonsl_jpr_t object, or NULL on error.
|
|
*/
|
|
JSONSL_API
|
|
jsonsl_jpr_t jsonsl_jpr_new(const char *path, jsonsl_error_t *errp);
|
|
|
|
/**
|
|
* Destroy a JPR object
|
|
*/
|
|
JSONSL_API
|
|
void jsonsl_jpr_destroy(jsonsl_jpr_t jpr);
|
|
|
|
/**
|
|
* Match a JSON object against a type and specific level
|
|
*
|
|
* @param jpr the JPR object
|
|
* @param parent_type the type of the parent (should be T_LIST or T_OBJECT)
|
|
* @param parent_level the level of the parent
|
|
* @param key the 'key' of the child. If the parent is an array, this should be
|
|
* empty.
|
|
* @param nkey - the length of the key. If the parent is an array (T_LIST), then
|
|
* this should be the current index.
|
|
*
|
|
* NOTE: The key of the child means any kind of associative data related to the
|
|
* element. Thus: <<< { "foo" : [ >>,
|
|
* the opening array's key is "foo".
|
|
*
|
|
* @return a status constant. This indicates whether a match was excluded, possible,
|
|
* or successful.
|
|
*/
|
|
JSONSL_API
|
|
jsonsl_jpr_match_t jsonsl_jpr_match(jsonsl_jpr_t jpr,
|
|
unsigned int parent_type,
|
|
unsigned int parent_level,
|
|
const char *key, size_t nkey);
|
|
|
|
/**
|
|
* Alternate matching algorithm. This matching algorithm does not use
|
|
* JSONPointer but relies on a more structured searching mechanism. It
|
|
* assumes that there is a clear distinction between array indices and
|
|
* object keys. In this case, the jsonsl_path_component_st::ptype should
|
|
* be set to @ref JSONSL_PATH_NUMERIC for an array index (the
|
|
* jsonsl_path_comonent_st::is_arridx field will be removed in a future
|
|
* version).
|
|
*
|
|
* @param jpr The path
|
|
* @param parent The parent structure. Can be NULL if this is the root object
|
|
* @param child The child structure. Should not be NULL
|
|
* @param key Object key, if an object
|
|
* @param nkey Length of object key
|
|
* @return Status constant if successful
|
|
*
|
|
* @note
|
|
* For successful matching, both the key and the path itself should be normalized
|
|
* to contain 'proper' utf8 sequences rather than utf16 '\uXXXX' escapes. This
|
|
* should currently be done in the application. Another version of this function
|
|
* may use a temporary buffer in such circumstances (allocated by the application).
|
|
*
|
|
* Since this function also checks the state of the child, it should only
|
|
* be called on PUSH callbacks, and not POP callbacks
|
|
*/
|
|
JSONSL_API
|
|
jsonsl_jpr_match_t
|
|
jsonsl_path_match(jsonsl_jpr_t jpr,
|
|
const struct jsonsl_state_st *parent,
|
|
const struct jsonsl_state_st *child,
|
|
const char *key, size_t nkey);
|
|
|
|
|
|
/**
|
|
* Associate a set of JPR objects with a lexer instance.
|
|
* This should be called before the lexer has been fed any data (and
|
|
* behavior is undefined if you don't adhere to this).
|
|
*
|
|
* After using this function, you may subsequently call match_state() on
|
|
* given states (presumably from within the callbacks).
|
|
*
|
|
* Note that currently the first JPR is the quickest and comes
|
|
* pre-allocated with the state structure. Further JPR objects
|
|
* are chained.
|
|
*
|
|
* @param jsn The lexer
|
|
* @param jprs An array of jsonsl_jpr_t objects
|
|
* @param njprs How many elements in the jprs array.
|
|
*/
|
|
JSONSL_API
|
|
void jsonsl_jpr_match_state_init(jsonsl_t jsn,
|
|
jsonsl_jpr_t *jprs,
|
|
size_t njprs);
|
|
|
|
/**
|
|
* This follows the same semantics as the normal match,
|
|
* except we infer parent and type information from the relevant state objects.
|
|
* The match status (for all possible JPR objects) is set in the *out parameter.
|
|
*
|
|
* If a match has succeeded, then its JPR object will be returned. In all other
|
|
* instances, NULL is returned;
|
|
*
|
|
* @param jpr The jsonsl_jpr_t handle
|
|
* @param state The jsonsl_state_st which is a candidate
|
|
* @param key The hash key (if applicable, can be NULL if parent is list)
|
|
* @param nkey Length of hash key (if applicable, can be zero if parent is list)
|
|
* @param out A pointer to a jsonsl_jpr_match_t. This will be populated with
|
|
* the match result
|
|
*
|
|
* @return If a match was completed in full, then the JPR object containing
|
|
* the matching path will be returned. Otherwise, the return is NULL (note, this
|
|
* does not mean matching has failed, it can still be part of the match: check
|
|
* the out parameter).
|
|
*/
|
|
JSONSL_API
|
|
jsonsl_jpr_t jsonsl_jpr_match_state(jsonsl_t jsn,
|
|
struct jsonsl_state_st *state,
|
|
const char *key,
|
|
size_t nkey,
|
|
jsonsl_jpr_match_t *out);
|
|
|
|
|
|
/**
|
|
* Cleanup any memory allocated and any states set by
|
|
* match_state_init() and match_state()
|
|
* @param jsn The lexer
|
|
*/
|
|
JSONSL_API
|
|
void jsonsl_jpr_match_state_cleanup(jsonsl_t jsn);
|
|
|
|
/**
|
|
* Return a string representation of the match result returned by match()
|
|
*/
|
|
JSONSL_API
|
|
const char *jsonsl_strmatchtype(jsonsl_jpr_match_t match);
|
|
|
|
/* @}*/
|
|
|
|
/**
|
|
* Utility function to convert escape sequences into their original form.
|
|
*
|
|
* The decoders I've sampled do not seem to specify a standard behavior of what
|
|
* to escape/unescape.
|
|
*
|
|
* RFC 4627 Mandates only that the quoute, backslash, and ASCII control
|
|
* characters (0x00-0x1f) be escaped. It is often common for applications
|
|
* to escape a '/' - however this may also be desired behavior. the JSON
|
|
* spec is not clear on this, and therefore jsonsl leaves it up to you.
|
|
*
|
|
* Additionally, sometimes you may wish to _normalize_ JSON. This is specifically
|
|
* true when dealing with 'u-escapes' which can be expressed perfectly fine
|
|
* as utf8. One use case for normalization is JPR string comparison, in which
|
|
* case two effectively equivalent strings may not match because one is using
|
|
* u-escapes and the other proper utf8. To normalize u-escapes only, pass in
|
|
* an empty `toEscape` table, enabling only the `u` index.
|
|
*
|
|
* @param in The input string.
|
|
* @param out An allocated output (should be the same size as in)
|
|
* @param len the size of the buffer
|
|
* @param toEscape - A sparse array of characters to unescape. Characters
|
|
* which are not present in this array, e.g. toEscape['c'] == 0 will be
|
|
* ignored and passed to the output in their original form.
|
|
* @param oflags If not null, and a \uXXXX escape expands to a non-ascii byte,
|
|
* then this variable will have the SPECIALf_NONASCII flag on.
|
|
*
|
|
* @param err A pointer to an error variable. If an error ocurrs, it will be
|
|
* set in this variable
|
|
* @param errat If not null and an error occurs, this will be set to point
|
|
* to the position within the string at which the offending character was
|
|
* encountered.
|
|
*
|
|
* @return The effective size of the output buffer.
|
|
*
|
|
* @note
|
|
* This function now encodes the UTF8 equivalents of utf16 escapes (i.e.
|
|
* 'u-escapes'). Previously this would encode the escapes as utf16 literals,
|
|
* which while still correct in some sense was confusing for many (especially
|
|
* considering that the inputs were variations of char).
|
|
*
|
|
* @note
|
|
* The output buffer will never be larger than the input buffer, since
|
|
* standard escape sequences (i.e. '\t') occupy two bytes in the source
|
|
* but only one byte (when unescaped) in the output. Likewise u-escapes
|
|
* (i.e. \uXXXX) will occupy six bytes in the source, but at the most
|
|
* two bytes when escaped.
|
|
*/
|
|
JSONSL_API
|
|
size_t jsonsl_util_unescape_ex(const char *in,
|
|
char *out,
|
|
size_t len,
|
|
const int toEscape[128],
|
|
unsigned *oflags,
|
|
jsonsl_error_t *err,
|
|
const char **errat);
|
|
|
|
/**
|
|
* Convenience macro to avoid passing too many parameters
|
|
*/
|
|
#define jsonsl_util_unescape(in, out, len, toEscape, err) \
|
|
jsonsl_util_unescape_ex(in, out, len, toEscape, NULL, err, NULL)
|
|
|
|
#endif /* JSONSL_NO_JPR */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif /* __cplusplus */
|
|
|
|
#endif /* JSONSL_H_ */
|