json-tutorial/tutorial05_answer/leptjson.c at master · showcode-shutup/json-tutorial · GitHub

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#ifdef _WINDOWS

#define _CRTDBG_MAP_ALLOC

#include <crtdbg.h>

#endif

#include "leptjson.h"

#include <assert.h> /* assert() */

#include <errno.h> /* errno, ERANGE */

#include <math.h> /* HUGE_VAL */

#include <stdlib.h> /* NULL, malloc(), realloc(), free(), strtod() */

#include <string.h> /* memcpy() */

#ifndef LEPT_PARSE_STACK_INIT_SIZE

#define LEPT_PARSE_STACK_INIT_SIZE 256

#endif

#define EXPECT(c, ch) do { assert(*c->json == (ch)); c->json++; } while(0)

#define ISDIGIT(ch) ((ch) >= '0' && (ch) <= '9')

#define ISDIGIT1TO9(ch) ((ch) >= '1' && (ch) <= '9')

#define PUTC(c, ch) do { *(char*)lept_context_push(c, sizeof(char)) = (ch); } while(0)

typedef struct {

const char* json;

char* stack;

size_t size, top;

}lept_context;

static void* lept_context_push(lept_context* c, size_t size) {

void* ret;

assert(size > 0);

if (c->top + size >= c->size) {

if (c->size == 0)

c->size = LEPT_PARSE_STACK_INIT_SIZE;

while (c->top + size >= c->size)

c->size += c->size >> 1; /* c->size * 1.5 */

c->stack = (char*)realloc(c->stack, c->size);

}

ret = c->stack + c->top;

c->top += size;

return ret;

}

static void* lept_context_pop(lept_context* c, size_t size) {

assert(c->top >= size);

return c->stack + (c->top -= size);

}

static void lept_parse_whitespace(lept_context* c) {

const char *p = c->json;

while (*p == ' ' || *p == '\t' || *p == '\n' || *p == '\r')

p++;

c->json = p;

}

static int lept_parse_literal(lept_context* c, lept_value* v, const char* literal, lept_type type) {

size_t i;

EXPECT(c, literal[0]);

for (i = 0; literal[i + 1]; i++)

if (c->json[i] != literal[i + 1])

return LEPT_PARSE_INVALID_VALUE;

c->json += i;

v->type = type;

return LEPT_PARSE_OK;

}

static int lept_parse_number(lept_context* c, lept_value* v) {

const char* p = c->json;

if (*p == '-') p++;

if (*p == '0') p++;

else {

if (!ISDIGIT1TO9(*p)) return LEPT_PARSE_INVALID_VALUE;

for (p++; ISDIGIT(*p); p++);

}

if (*p == '.') {

p++;

if (!ISDIGIT(*p)) return LEPT_PARSE_INVALID_VALUE;

for (p++; ISDIGIT(*p); p++);

}

if (*p == 'e' || *p == 'E') {

p++;

if (*p == '+' || *p == '-') p++;

if (!ISDIGIT(*p)) return LEPT_PARSE_INVALID_VALUE;

for (p++; ISDIGIT(*p); p++);

}

errno = 0;

v->u.n = strtod(c->json, NULL);

if (errno == ERANGE && (v->u.n == HUGE_VAL || v->u.n == -HUGE_VAL))

return LEPT_PARSE_NUMBER_TOO_BIG;

v->type = LEPT_NUMBER;

c->json = p;

return LEPT_PARSE_OK;

}

static const char* lept_parse_hex4(const char* p, unsigned* u) {

int i;

*u = 0;

for (i = 0; i < 4; i++) {

char ch = *p++;

*u <<= 4;

if (ch >= '0' && ch <= '9') *u |= ch - '0';

else if (ch >= 'A' && ch <= 'F') *u |= ch - ('A' - 10);

else if (ch >= 'a' && ch <= 'f') *u |= ch - ('a' - 10);

else return NULL;

}

return p;

}

static void lept_encode_utf8(lept_context* c, unsigned u) {

if (u <= 0x7F)

PUTC(c, u & 0xFF);

else if (u <= 0x7FF) {

PUTC(c, 0xC0 | ((u >> 6) & 0xFF));

PUTC(c, 0x80 | ( u & 0x3F));

}

else if (u <= 0xFFFF) {

PUTC(c, 0xE0 | ((u >> 12) & 0xFF));

PUTC(c, 0x80 | ((u >> 6) & 0x3F));

PUTC(c, 0x80 | ( u & 0x3F));

}

else {

assert(u <= 0x10FFFF);

PUTC(c, 0xF0 | ((u >> 18) & 0xFF));

PUTC(c, 0x80 | ((u >> 12) & 0x3F));

PUTC(c, 0x80 | ((u >> 6) & 0x3F));

PUTC(c, 0x80 | ( u & 0x3F));

}

#define STRING_ERROR(ret) do { c->top = head; return ret; } while(0)

static int lept_parse_string(lept_context* c, lept_value* v) {

size_t head = c->top, len;

unsigned u, u2;

const char* p;

EXPECT(c, '\"');

p = c->json;

for (;;) {

char ch = *p++;

switch (ch) {

case '\"':

len = c->top - head;

lept_set_string(v, (const char*)lept_context_pop(c, len), len);

c->json = p;

return LEPT_PARSE_OK;

case '\\':

switch (*p++) {

case '\"': PUTC(c, '\"'); break;

case '\\': PUTC(c, '\\'); break;

case '/': PUTC(c, '/' ); break;

case 'b': PUTC(c, '\b'); break;

case 'f': PUTC(c, '\f'); break;

case 'n': PUTC(c, '\n'); break;

case 'r': PUTC(c, '\r'); break;

case 't': PUTC(c, '\t'); break;

case 'u':

if (!(p = lept_parse_hex4(p, &u)))

STRING_ERROR(LEPT_PARSE_INVALID_UNICODE_HEX);

if (u >= 0xD800 && u <= 0xDBFF) { /* surrogate pair */

if (*p++ != '\\')

STRING_ERROR(LEPT_PARSE_INVALID_UNICODE_SURROGATE);

if (*p++ != 'u')

STRING_ERROR(LEPT_PARSE_INVALID_UNICODE_SURROGATE);

if (!(p = lept_parse_hex4(p, &u2)))

STRING_ERROR(LEPT_PARSE_INVALID_UNICODE_HEX);

if (u2 < 0xDC00 || u2 > 0xDFFF)

STRING_ERROR(LEPT_PARSE_INVALID_UNICODE_SURROGATE);

u = (((u - 0xD800) << 10) | (u2 - 0xDC00)) + 0x10000;

}

lept_encode_utf8(c, u);

break;

default:

STRING_ERROR(LEPT_PARSE_INVALID_STRING_ESCAPE);

}

break;

case '\0':

STRING_ERROR(LEPT_PARSE_MISS_QUOTATION_MARK);

default:

if ((unsigned char)ch < 0x20)

STRING_ERROR(LEPT_PARSE_INVALID_STRING_CHAR);

PUTC(c, ch);

}

static int lept_parse_value(lept_context* c, lept_value* v);

static int lept_parse_array(lept_context* c, lept_value* v) {

size_t i, size = 0;

int ret;

EXPECT(c, '[');

lept_parse_whitespace(c);

if (*c->json == ']') {

c->json++;

v->type = LEPT_ARRAY;

v->u.a.size = 0;

v->u.a.e = NULL;

return LEPT_PARSE_OK;

}

for (;;) {

lept_value e;

lept_init(&e);

if ((ret = lept_parse_value(c, &e)) != LEPT_PARSE_OK)

break;

memcpy(lept_context_push(c, sizeof(lept_value)), &e, sizeof(lept_value));

size++;

lept_parse_whitespace(c);

if (*c->json == ',') {

c->json++;

lept_parse_whitespace(c);

}

else if (*c->json == ']') {

c->json++;

v->type = LEPT_ARRAY;

v->u.a.size = size;

size *= sizeof(lept_value);

memcpy(v->u.a.e = (lept_value*)malloc(size), lept_context_pop(c, size), size);

return LEPT_PARSE_OK;

}

else {

ret = LEPT_PARSE_MISS_COMMA_OR_SQUARE_BRACKET;

break;

}

/* Pop and free values on the stack */

for (i = 0; i < size; i++)

lept_free((lept_value*)lept_context_pop(c, sizeof(lept_value)));

return ret;

}

static int lept_parse_value(lept_context* c, lept_value* v) {

switch (*c->json) {

case 't': return lept_parse_literal(c, v, "true", LEPT_TRUE);

case 'f': return lept_parse_literal(c, v, "false", LEPT_FALSE);

case 'n': return lept_parse_literal(c, v, "null", LEPT_NULL);

default: return lept_parse_number(c, v);

case '"': return lept_parse_string(c, v);

case '[': return lept_parse_array(c, v);

case '\0': return LEPT_PARSE_EXPECT_VALUE;

}

int lept_parse(lept_value* v, const char* json) {

lept_context c;

int ret;

assert(v != NULL);

c.json = json;

c.stack = NULL;

c.size = c.top = 0;

lept_init(v);

lept_parse_whitespace(&c);

if ((ret = lept_parse_value(&c, v)) == LEPT_PARSE_OK) {

lept_parse_whitespace(&c);

if (*c.json != '\0') {

v->type = LEPT_NULL;

ret = LEPT_PARSE_ROOT_NOT_SINGULAR;

}

assert(c.top == 0);

free(c.stack);

return ret;

}

void lept_free(lept_value* v) {

size_t i;

assert(v != NULL);

switch (v->type) {

case LEPT_STRING:

free(v->u.s.s);

break;

case LEPT_ARRAY:

for (i = 0; i < v->u.a.size; i++)

lept_free(&v->u.a.e[i]);

free(v->u.a.e);

break;

default: break;

}

v->type = LEPT_NULL;

}

lept_type lept_get_type(const lept_value* v) {

assert(v != NULL);

return v->type;

}

int lept_get_boolean(const lept_value* v) {

assert(v != NULL && (v->type == LEPT_TRUE || v->type == LEPT_FALSE));

return v->type == LEPT_TRUE;

}

void lept_set_boolean(lept_value* v, int b) {

lept_free(v);

v->type = b ? LEPT_TRUE : LEPT_FALSE;

}

double lept_get_number(const lept_value* v) {

assert(v != NULL && v->type == LEPT_NUMBER);

return v->u.n;

}

void lept_set_number(lept_value* v, double n) {

lept_free(v);

v->u.n = n;

v->type = LEPT_NUMBER;

}

const char* lept_get_string(const lept_value* v) {

assert(v != NULL && v->type == LEPT_STRING);

return v->u.s.s;

}

size_t lept_get_string_length(const lept_value* v) {

assert(v != NULL && v->type == LEPT_STRING);

return v->u.s.len;

}

void lept_set_string(lept_value* v, const char* s, size_t len) {

assert(v != NULL && (s != NULL || len == 0));

lept_free(v);

v->u.s.s = (char*)malloc(len + 1);

memcpy(v->u.s.s, s, len);

v->u.s.s[len] = '\0';

v->u.s.len = len;

v->type = LEPT_STRING;

}

size_t lept_get_array_size(const lept_value* v) {

assert(v != NULL && v->type == LEPT_ARRAY);

return v->u.a.size;

}

lept_value* lept_get_array_element(const lept_value* v, size_t index) {

assert(v != NULL && v->type == LEPT_ARRAY);

assert(index < v->u.a.size);

return &v->u.a.e[index];

}

json-tutorial/tutorial05_answer/leptjson.c at master · showcode-shutup/json-tutorial · GitHub

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