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_END_OF_ARRAY,
JSON_ERROR_UNEXPECTED_OBJECT,
JSON_ERROR_UNEXPECTED_END_OF_OBJECT,
JSON_ERROR_UNEXPECTED_STRING
};

View file

@ -43,6 +43,14 @@ push(struct jsonparse_state *state, char c)
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
pop(struct jsonparse_state *state)
{
@ -50,25 +58,31 @@ pop(struct jsonparse_state *state)
return JSON_TYPE_ERROR;
}
state->depth--;
state->vtype = state->stack[state->depth];
return state->stack[state->depth];
}
/*--------------------------------------------------------------------*/
/* will pass by the value and store the start and length of the value for
atomic types */
/*--------------------------------------------------------------------*/
static void
static char
atomic(struct jsonparse_state *state, char type)
{
char c;
const char *str;
int len;
state->vstart = state->pos;
state->vtype = type;
if(type == JSON_TYPE_STRING || type == JSON_TYPE_PAIR_NAME) {
while((c = state->json[state->pos++]) && c != '"') {
if(c == '\\') {
state->pos++; /* skip current char */
}
}
if (c != '"') {
state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR;
}
state->vlen = state->pos - state->vstart - 1;
} else if(type == JSON_TYPE_NUMBER) {
do {
@ -82,8 +96,31 @@ atomic(struct jsonparse_state *state, char type)
/* need to back one step since first char is already gone */
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;
}
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;
}
}
/* no other types for now... */
state->vtype = type;
return state->vtype;
}
/*--------------------------------------------------------------------*/
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
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->depth = 0;
state->error = 0;
state->vtype = 0;
state->stack[0] = 0;
}
/*--------------------------------------------------------------------*/
@ -113,31 +162,33 @@ jsonparse_next(struct jsonparse_state *state)
{
char c;
char s;
char v;
skip_ws(state);
c = state->json[state->pos];
s = jsonparse_get_type(state);
v = state->vtype;
state->pos++;
switch(c) {
case '{':
push(state, c);
if((s == 0 && v == 0) || s == '[' || s == ':') {
push(state, c);
} else {
state->error = JSON_ERROR_UNEXPECTED_OBJECT;
return JSON_TYPE_ERROR;
}
return c;
case '}':
if(s == ':' && state->vtype != 0) {
/* printf("Popping vtype: '%c'\n", state->vtype); */
pop(state);
s = jsonparse_get_type(state);
}
if(s == '{') {
if((s == ':' && v != ',' && v != 0 ) || (s == '{' && v == 0)) {
pop(state);
} else {
state->error = JSON_ERROR_SYNTAX;
state->error = JSON_ERROR_UNEXPECTED_END_OF_OBJECT;
return JSON_TYPE_ERROR;
}
return c;
case ']':
if(s == '[') {
if(s == '[' && v != ',') {
pop(state);
} else {
state->error = JSON_ERROR_UNEXPECTED_END_OF_ARRAY;
@ -145,41 +196,67 @@ jsonparse_next(struct jsonparse_state *state)
}
return c;
case ':':
push(state, c);
return c;
if(s == '{' && v == 'N') {
modify(state, ':');
state->vtype = 0;
} else {
state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR;
}
return jsonparse_next(state);
case ',':
/* if x:y ... , */
if(s == ':' && state->vtype != 0) {
pop(state);
if(s == ':' && v != 0) {
modify(state, '{');
state->vtype = c;
} else if(s == '[') {
/* ok! */
state->vtype = c;
} else {
state->error = JSON_ERROR_SYNTAX;
return JSON_TYPE_ERROR;
}
return c;
case '"':
if(s == '{' || s == '[' || s == ':') {
atomic(state, c = (s == '{' ? JSON_TYPE_PAIR_NAME : c));
if((s == 0 && v == 0) || s == '{' || s == '[' || s == ':') {
return atomic(state, c = (s == '{' ? JSON_TYPE_PAIR_NAME : c));
} else {
state->error = JSON_ERROR_UNEXPECTED_STRING;
return JSON_TYPE_ERROR;
}
return c;
case '[':
if(s == '{' || s == '[' || s == ':') {
if((s == 0 && v == 0) || s == '[' || s == ':') {
push(state, c);
} else {
state->error = JSON_ERROR_UNEXPECTED_ARRAY;
return JSON_TYPE_ERROR;
}
return c;
case 0:
if(v == 0 || state->depth > 0) {
state->error = JSON_ERROR_SYNTAX;
}
return JSON_TYPE_ERROR;
default:
if(s == ':' || s == '[') {
if(c <= '9' && c >= '0') {
atomic(state, JSON_TYPE_NUMBER);
return JSON_TYPE_NUMBER;
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;
@ -192,16 +269,31 @@ jsonparse_next(struct jsonparse_state *state)
int
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;
}
size = size <= state->vlen ? (size - 1) : state->vlen;
for(i = 0; i < size; i++) {
str[i] = state->json[state->vstart + i];
for(i = 0, o = 0; i < state->vlen && o < size - 1; i++) {
c = 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;
}
continue;
}
str[o++] = c;
}
str[i] = 0;
str[o] = 0;
return state->vtype;
}
/*--------------------------------------------------------------------*/
@ -228,7 +320,7 @@ jsonparse_get_value_as_long(struct jsonparse_state *state)
int
jsonparse_strcmp_value(struct jsonparse_state *state, const char *str)
{
if(state->vtype == 0) {
if(!is_atomic(state)) {
return -1;
}
return strncmp(str, &state->json[state->vstart], state->vlen);