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/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010-2018 Andy Green <andy@warmcat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation:
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*
* included from libwebsockets.h
*/
/** \defgroup lejp JSON parser
* ##JSON parsing related functions
* \ingroup lwsapi
*
* LEJP is an extremely lightweight JSON stream parser included in lws.
*/
//@{
struct lejp_ctx;
#if !defined(LWS_ARRAY_SIZE)
#define LWS_ARRAY_SIZE(_x) (sizeof(_x) / sizeof(_x[0]))
#endif
#define LEJP_FLAG_WS_KEEP 64
#define LEJP_FLAG_WS_COMMENTLINE 32
enum lejp_states {
LEJP_IDLE = 0,
LEJP_MEMBERS = 1,
LEJP_M_P = 2,
LEJP_MP_STRING = LEJP_FLAG_WS_KEEP | 3,
LEJP_MP_STRING_ESC = LEJP_FLAG_WS_KEEP | 4,
LEJP_MP_STRING_ESC_U1 = LEJP_FLAG_WS_KEEP | 5,
LEJP_MP_STRING_ESC_U2 = LEJP_FLAG_WS_KEEP | 6,
LEJP_MP_STRING_ESC_U3 = LEJP_FLAG_WS_KEEP | 7,
LEJP_MP_STRING_ESC_U4 = LEJP_FLAG_WS_KEEP | 8,
LEJP_MP_DELIM = 9,
LEJP_MP_VALUE = 10,
LEJP_MP_VALUE_NUM_INT = LEJP_FLAG_WS_KEEP | 11,
LEJP_MP_VALUE_NUM_EXP = LEJP_FLAG_WS_KEEP | 12,
LEJP_MP_VALUE_TOK = LEJP_FLAG_WS_KEEP | 13,
LEJP_MP_COMMA_OR_END = 14,
LEJP_MP_ARRAY_END = 15,
};
enum lejp_reasons {
LEJP_CONTINUE = -1,
LEJP_REJECT_IDLE_NO_BRACE = -2,
LEJP_REJECT_MEMBERS_NO_CLOSE = -3,
LEJP_REJECT_MP_NO_OPEN_QUOTE = -4,
LEJP_REJECT_MP_STRING_UNDERRUN = -5,
LEJP_REJECT_MP_ILLEGAL_CTRL = -6,
LEJP_REJECT_MP_STRING_ESC_ILLEGAL_ESC = -7,
LEJP_REJECT_ILLEGAL_HEX = -8,
LEJP_REJECT_MP_DELIM_MISSING_COLON = -9,
LEJP_REJECT_MP_DELIM_BAD_VALUE_START = -10,
LEJP_REJECT_MP_VAL_NUM_INT_NO_FRAC = -11,
LEJP_REJECT_MP_VAL_NUM_FORMAT = -12,
LEJP_REJECT_MP_VAL_NUM_EXP_BAD_EXP = -13,
LEJP_REJECT_MP_VAL_TOK_UNKNOWN = -14,
LEJP_REJECT_MP_C_OR_E_UNDERF = -15,
LEJP_REJECT_MP_C_OR_E_NOTARRAY = -16,
LEJP_REJECT_MP_ARRAY_END_MISSING = -17,
LEJP_REJECT_STACK_OVERFLOW = -18,
LEJP_REJECT_MP_DELIM_ISTACK = -19,
LEJP_REJECT_NUM_TOO_LONG = -20,
LEJP_REJECT_MP_C_OR_E_NEITHER = -21,
LEJP_REJECT_UNKNOWN = -22,
LEJP_REJECT_CALLBACK = -23
};
#define LEJP_FLAG_CB_IS_VALUE 64
enum lejp_callbacks {
LEJPCB_CONSTRUCTED = 0,
LEJPCB_DESTRUCTED = 1,
LEJPCB_START = 2,
LEJPCB_COMPLETE = 3,
LEJPCB_FAILED = 4,
LEJPCB_PAIR_NAME = 5,
LEJPCB_VAL_TRUE = LEJP_FLAG_CB_IS_VALUE | 6,
LEJPCB_VAL_FALSE = LEJP_FLAG_CB_IS_VALUE | 7,
LEJPCB_VAL_NULL = LEJP_FLAG_CB_IS_VALUE | 8,
LEJPCB_VAL_NUM_INT = LEJP_FLAG_CB_IS_VALUE | 9,
LEJPCB_VAL_NUM_FLOAT = LEJP_FLAG_CB_IS_VALUE | 10,
LEJPCB_VAL_STR_START = 11, /* notice handle separately */
LEJPCB_VAL_STR_CHUNK = LEJP_FLAG_CB_IS_VALUE | 12,
LEJPCB_VAL_STR_END = LEJP_FLAG_CB_IS_VALUE | 13,
LEJPCB_ARRAY_START = 14,
LEJPCB_ARRAY_END = 15,
LEJPCB_OBJECT_START = 16,
LEJPCB_OBJECT_END = 17,
};
/**
* _lejp_callback() - User parser actions
* \param ctx: LEJP context
* \param reason: Callback reason
*
* Your user callback is associated with the context at construction time,
* and receives calls as the parsing progresses.
*
* All of the callbacks may be ignored and just return 0.
*
* The reasons it might get called, found in @reason, are:
*
* LEJPCB_CONSTRUCTED: The context was just constructed... you might want to
* perform one-time allocation for the life of the context.
*
* LEJPCB_DESTRUCTED: The context is being destructed... if you made any
* allocations at construction-time, you can free them now
*
* LEJPCB_START: Parsing is beginning at the first byte of input
*
* LEJPCB_COMPLETE: Parsing has completed successfully. You'll get a 0 or
* positive return code from lejp_parse indicating the
* amount of unused bytes left in the input buffer
*
* LEJPCB_FAILED: Parsing failed. You'll get a negative error code
* returned from lejp_parse
*
* LEJPCB_PAIR_NAME: When a "name":"value" pair has had the name parsed,
* this callback occurs. You can find the new name at
* the end of ctx->path[]
*
* LEJPCB_VAL_TRUE: The "true" value appeared
*
* LEJPCB_VAL_FALSE: The "false" value appeared
*
* LEJPCB_VAL_NULL: The "null" value appeared
*
* LEJPCB_VAL_NUM_INT: A string representing an integer is in ctx->buf
*
* LEJPCB_VAL_NUM_FLOAT: A string representing a float is in ctx->buf
*
* LEJPCB_VAL_STR_START: We are starting to parse a string, no data yet
*
* LEJPCB_VAL_STR_CHUNK: We parsed LEJP_STRING_CHUNK -1 bytes of string data in
* ctx->buf, which is as much as we can buffer, so we are
* spilling it. If all your strings are less than
* LEJP_STRING_CHUNK - 1 bytes, you will never see this
* callback.
*
* LEJPCB_VAL_STR_END: String parsing has completed, the last chunk of the
* string is in ctx->buf.
*
* LEJPCB_ARRAY_START: An array started
*
* LEJPCB_ARRAY_END: An array ended
*
* LEJPCB_OBJECT_START: An object started
*
* LEJPCB_OBJECT_END: An object ended
*/
LWS_EXTERN signed char _lejp_callback(struct lejp_ctx *ctx, char reason);
typedef signed char (*lejp_callback)(struct lejp_ctx *ctx, char reason);
#ifndef LEJP_MAX_PARSING_STACK_DEPTH
#define LEJP_MAX_PARSING_STACK_DEPTH 5
#endif
#ifndef LEJP_MAX_DEPTH
#define LEJP_MAX_DEPTH 12
#endif
#ifndef LEJP_MAX_INDEX_DEPTH
#define LEJP_MAX_INDEX_DEPTH 5
#endif
#ifndef LEJP_MAX_PATH
#define LEJP_MAX_PATH 128
#endif
#ifndef LEJP_STRING_CHUNK
/* must be >= 30 to assemble floats */
#define LEJP_STRING_CHUNK 254
#endif
enum num_flags {
LEJP_SEEN_MINUS = (1 << 0),
LEJP_SEEN_POINT = (1 << 1),
LEJP_SEEN_POST_POINT = (1 << 2),
LEJP_SEEN_EXP = (1 << 3)
};
struct _lejp_stack {
char s; /* lejp_state stack*/
char p; /* path length */
char i; /* index array length */
char b; /* user bitfield */
};
struct _lejp_parsing_stack {
void *user; /* private to the stack level */
signed char (*callback)(struct lejp_ctx *ctx, char reason);
const char * const *paths;
uint8_t count_paths;
uint8_t ppos;
uint8_t path_match;
};
struct lejp_ctx {
/* sorted by type for most compact alignment
*
* pointers
*/
void *user;
/* arrays */
struct _lejp_parsing_stack pst[LEJP_MAX_PARSING_STACK_DEPTH];
struct _lejp_stack st[LEJP_MAX_DEPTH];
uint16_t i[LEJP_MAX_INDEX_DEPTH]; /* index array */
uint16_t wild[LEJP_MAX_INDEX_DEPTH]; /* index array */
char path[LEJP_MAX_PATH];
char buf[LEJP_STRING_CHUNK + 1];
/* size_t */
size_t path_stride; /* 0 means default ptr size, else stride */
/* int */
uint32_t line;
/* short */
uint16_t uni;
/* char */
uint8_t npos;
uint8_t dcount;
uint8_t f;
uint8_t sp; /* stack head */
uint8_t ipos; /* index stack depth */
uint8_t count_paths;
uint8_t path_match;
uint8_t path_match_len;
uint8_t wildcount;
uint8_t pst_sp; /* parsing stack head */
};
LWS_VISIBLE LWS_EXTERN void
lejp_construct(struct lejp_ctx *ctx,
signed char (*callback)(struct lejp_ctx *ctx, char reason),
void *user, const char * const *paths, unsigned char paths_count);
LWS_VISIBLE LWS_EXTERN void
lejp_destruct(struct lejp_ctx *ctx);
LWS_VISIBLE LWS_EXTERN int
lejp_parse(struct lejp_ctx *ctx, const unsigned char *json, int len);
LWS_VISIBLE LWS_EXTERN void
lejp_change_callback(struct lejp_ctx *ctx,
signed char (*callback)(struct lejp_ctx *ctx, char reason));
/*
* push the current paths / paths_count and lejp_cb to a stack in the ctx, and
* start using the new ones
*/
LWS_VISIBLE LWS_EXTERN int
lejp_parser_push(struct lejp_ctx *ctx, void *user, const char * const *paths,
unsigned char paths_count, lejp_callback lejp_cb);
/*
* pop the previously used paths / paths_count and lejp_cb, and continue
* parsing using those as before
*/
LWS_VISIBLE LWS_EXTERN int
lejp_parser_pop(struct lejp_ctx *ctx);
/* exported for use when reevaluating a path for use with a subcontext */
LWS_VISIBLE LWS_EXTERN void
lejp_check_path_match(struct lejp_ctx *ctx);
LWS_VISIBLE LWS_EXTERN int
lejp_get_wildcard(struct lejp_ctx *ctx, int wildcard, char *dest, int len);
LWS_VISIBLE LWS_EXTERN const char *
lejp_error_to_string(int e);
//@}
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