jsonparse: multiple improvements

* input string now can be any json value type
* syntax handling completed
* stack is now used more efficiently for objects
* implemented atomic values true, false, and null
* jsonparse_copy_value now handles escapes
This commit is contained in:
Jeff Kent 2015-12-28 09:47:12 -06:00
parent ca919ab0b0
commit 7dc1581631
2 changed files with 125 additions and 32 deletions

View file

@ -62,6 +62,7 @@ enum {
JSON_ERROR_UNEXPECTED_ARRAY, JSON_ERROR_UNEXPECTED_ARRAY,
JSON_ERROR_UNEXPECTED_END_OF_ARRAY, JSON_ERROR_UNEXPECTED_END_OF_ARRAY,
JSON_ERROR_UNEXPECTED_OBJECT, JSON_ERROR_UNEXPECTED_OBJECT,
JSON_ERROR_UNEXPECTED_END_OF_OBJECT,
JSON_ERROR_UNEXPECTED_STRING JSON_ERROR_UNEXPECTED_STRING
}; };

View file

@ -43,6 +43,14 @@ push(struct jsonparse_state *state, char c)
return state->depth < JSONPARSE_MAX_DEPTH; return state->depth < JSONPARSE_MAX_DEPTH;
} }
/*--------------------------------------------------------------------*/ /*--------------------------------------------------------------------*/
static void
modify(struct jsonparse_state *state, char c)
{
if(state->depth > 0) {
state->stack[state->depth - 1] = c;
}
}
/*--------------------------------------------------------------------*/
static char static char
pop(struct jsonparse_state *state) pop(struct jsonparse_state *state)
{ {
@ -50,25 +58,31 @@ pop(struct jsonparse_state *state)
return JSON_TYPE_ERROR; return JSON_TYPE_ERROR;
} }
state->depth--; state->depth--;
state->vtype = state->stack[state->depth];
return state->stack[state->depth]; return state->stack[state->depth];
} }
/*--------------------------------------------------------------------*/ /*--------------------------------------------------------------------*/
/* will pass by the value and store the start and length of the value for /* will pass by the value and store the start and length of the value for
atomic types */ atomic types */
/*--------------------------------------------------------------------*/ /*--------------------------------------------------------------------*/
static void static char
atomic(struct jsonparse_state *state, char type) atomic(struct jsonparse_state *state, char type)
{ {
char c; char c;
const char *str;
int len;
state->vstart = state->pos; state->vstart = state->pos;
state->vtype = type;
if(type == JSON_TYPE_STRING || type == JSON_TYPE_PAIR_NAME) { if(type == JSON_TYPE_STRING || type == JSON_TYPE_PAIR_NAME) {
while((c = state->json[state->pos++]) && c != '"') { while((c = state->json[state->pos++]) && c != '"') {
if(c == '\\') { if(c == '\\') {
state->pos++; /* skip current char */ state->pos++; /* skip current char */
} }
} }
if (c != '"') {
state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR;
}
state->vlen = state->pos - state->vstart - 1; state->vlen = state->pos - state->vstart - 1;
} else if(type == JSON_TYPE_NUMBER) { } else if(type == JSON_TYPE_NUMBER) {
do { do {
@ -82,8 +96,31 @@ atomic(struct jsonparse_state *state, char type)
/* need to back one step since first char is already gone */ /* need to back one step since first char is already gone */
state->vstart--; state->vstart--;
state->vlen = state->pos - state->vstart; state->vlen = state->pos - state->vstart;
} else if(type == JSON_TYPE_NULL || type == JSON_TYPE_TRUE || type == JSON_TYPE_FALSE) {
state->vstart--;
switch (type) {
case JSON_TYPE_NULL: str = "null"; break;
case JSON_TYPE_TRUE: str = "true"; break;
case JSON_TYPE_FALSE: str = "false"; break;
default: str = ""; break;
} }
/* no other types for now... */
while ((c = state->json[state->pos]) && c != ' ' && c != ',' && c != ']' && c != '}') {
state->pos++;
}
state->vlen = state->pos - state->vstart;
len = strlen(str);
len = state->vlen > len ? state->vlen : len;
if (strncmp(str, &state->json[state->vstart], len) != 0) {
state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR;
}
}
state->vtype = type;
return state->vtype;
} }
/*--------------------------------------------------------------------*/ /*--------------------------------------------------------------------*/
static void static void
@ -97,6 +134,17 @@ skip_ws(struct jsonparse_state *state)
} }
} }
/*--------------------------------------------------------------------*/ /*--------------------------------------------------------------------*/
static int
is_atomic(struct jsonparse_state *state)
{
char v = state->vtype;
if(v == 'N' || v == '"' || v == '0' || v == 'n' || v == 't' || v == 'f') {
return 1;
} else {
return 0;
}
}
/*--------------------------------------------------------------------*/
void void
jsonparse_setup(struct jsonparse_state *state, const char *json, int len) jsonparse_setup(struct jsonparse_state *state, const char *json, int len)
{ {
@ -105,6 +153,7 @@ jsonparse_setup(struct jsonparse_state *state, const char *json, int len)
state->pos = 0; state->pos = 0;
state->depth = 0; state->depth = 0;
state->error = 0; state->error = 0;
state->vtype = 0;
state->stack[0] = 0; state->stack[0] = 0;
} }
/*--------------------------------------------------------------------*/ /*--------------------------------------------------------------------*/
@ -113,31 +162,33 @@ jsonparse_next(struct jsonparse_state *state)
{ {
char c; char c;
char s; char s;
char v;
skip_ws(state); skip_ws(state);
c = state->json[state->pos]; c = state->json[state->pos];
s = jsonparse_get_type(state); s = jsonparse_get_type(state);
v = state->vtype;
state->pos++; state->pos++;
switch(c) { switch(c) {
case '{': case '{':
if((s == 0 && v == 0) || s == '[' || s == ':') {
push(state, c); push(state, c);
} else {
state->error = JSON_ERROR_UNEXPECTED_OBJECT;
return JSON_TYPE_ERROR;
}
return c; return c;
case '}': case '}':
if(s == ':' && state->vtype != 0) { if((s == ':' && v != ',' && v != 0 ) || (s == '{' && v == 0)) {
/* printf("Popping vtype: '%c'\n", state->vtype); */
pop(state);
s = jsonparse_get_type(state);
}
if(s == '{') {
pop(state); pop(state);
} else { } else {
state->error = JSON_ERROR_SYNTAX; state->error = JSON_ERROR_UNEXPECTED_END_OF_OBJECT;
return JSON_TYPE_ERROR; return JSON_TYPE_ERROR;
} }
return c; return c;
case ']': case ']':
if(s == '[') { if(s == '[' && v != ',') {
pop(state); pop(state);
} else { } else {
state->error = JSON_ERROR_UNEXPECTED_END_OF_ARRAY; state->error = JSON_ERROR_UNEXPECTED_END_OF_ARRAY;
@ -145,41 +196,67 @@ jsonparse_next(struct jsonparse_state *state)
} }
return c; return c;
case ':': case ':':
push(state, c); if(s == '{' && v == 'N') {
return c; modify(state, ':');
state->vtype = 0;
} else {
state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR;
}
return jsonparse_next(state);
case ',': case ',':
/* if x:y ... , */ if(s == ':' && v != 0) {
if(s == ':' && state->vtype != 0) { modify(state, '{');
pop(state); state->vtype = c;
} else if(s == '[') { } else if(s == '[') {
/* ok! */ state->vtype = c;
} else { } else {
state->error = JSON_ERROR_SYNTAX; state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR; return JSON_TYPE_ERROR;
} }
return c; return c;
case '"': case '"':
if(s == '{' || s == '[' || s == ':') { if((s == 0 && v == 0) || s == '{' || s == '[' || s == ':') {
atomic(state, c = (s == '{' ? JSON_TYPE_PAIR_NAME : c)); return atomic(state, c = (s == '{' ? JSON_TYPE_PAIR_NAME : c));
} else { } else {
state->error = JSON_ERROR_UNEXPECTED_STRING; state->error = JSON_ERROR_UNEXPECTED_STRING;
return JSON_TYPE_ERROR; return JSON_TYPE_ERROR;
} }
return c; return c;
case '[': case '[':
if(s == '{' || s == '[' || s == ':') { if((s == 0 && v == 0) || s == '[' || s == ':') {
push(state, c); push(state, c);
} else { } else {
state->error = JSON_ERROR_UNEXPECTED_ARRAY; state->error = JSON_ERROR_UNEXPECTED_ARRAY;
return JSON_TYPE_ERROR; return JSON_TYPE_ERROR;
} }
return c; return c;
default: case 0:
if(s == ':' || s == '[') { if(v == 0 || state->depth > 0) {
if(c <= '9' && c >= '0') { state->error = JSON_ERROR_SYNTAX;
atomic(state, JSON_TYPE_NUMBER);
return JSON_TYPE_NUMBER;
} }
return JSON_TYPE_ERROR;
default:
if(s == 0 || s == ':' || s == '[') {
if (v != 0 && v != ',') {
state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR;
}
if(c == '-' || (c <= '9' && c >= '0')) {
return atomic(state, JSON_TYPE_NUMBER);
} else if(c == 'n') {
return atomic(state, JSON_TYPE_NULL);
} else if(c == 't') {
return atomic(state, JSON_TYPE_TRUE);
} else if(c == 'f') {
return atomic(state, JSON_TYPE_FALSE);
} else {
state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR;
}
} else if(s == '{') {
state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR;
} }
} }
return 0; return 0;
@ -192,16 +269,31 @@ jsonparse_next(struct jsonparse_state *state)
int int
jsonparse_copy_value(struct jsonparse_state *state, char *str, int size) jsonparse_copy_value(struct jsonparse_state *state, char *str, int size)
{ {
int i; int i, o;
char c;
if(state->vtype == 0) { if(!is_atomic(state)) {
return 0; return 0;
} }
size = size <= state->vlen ? (size - 1) : state->vlen; for(i = 0, o = 0; i < state->vlen && o < size - 1; i++) {
for(i = 0; i < size; i++) { c = state->json[state->vstart + i];
str[i] = state->json[state->vstart + i]; if(c == '\\') {
i++;
switch(state->json[state->vstart + i]) {
case '"': str[o++] = '"'; break;
case '\\': str[o++] = '\\'; break;
case '/': str[o++] = '/'; break;
case 'b': str[o++] = '\b'; break;
case 'f': str[o++] = '\f'; break;
case 'n': str[o++] = '\n'; break;
case 'r': str[o++] = '\r'; break;
case 't': str[o++] = '\t'; break;
} }
str[i] = 0; continue;
}
str[o++] = c;
}
str[o] = 0;
return state->vtype; return state->vtype;
} }
/*--------------------------------------------------------------------*/ /*--------------------------------------------------------------------*/
@ -228,7 +320,7 @@ jsonparse_get_value_as_long(struct jsonparse_state *state)
int int
jsonparse_strcmp_value(struct jsonparse_state *state, const char *str) jsonparse_strcmp_value(struct jsonparse_state *state, const char *str)
{ {
if(state->vtype == 0) { if(!is_atomic(state)) {
return -1; return -1;
} }
return strncmp(str, &state->json[state->vstart], state->vlen); return strncmp(str, &state->json[state->vstart], state->vlen);