jansson/src/dump.c
Petri Lehtinen 2630980f49 Zero the visited flag after encoding an empty array or object
Encoding an empty array or object worked, but encoding it again
(possibly after adding some items) failed, because the visited flag
(used for detecting circular references) wasn't zeroed.
2010-05-14 09:05:56 +03:00

442 lines
12 KiB
C

/*
* Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
*
* Jansson is free software; you can redistribute it and/or modify
* it under the terms of the MIT license. See LICENSE for details.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <jansson.h>
#include "jansson_private.h"
#include "strbuffer.h"
#include "utf.h"
#define MAX_INTEGER_STR_LENGTH 100
#define MAX_REAL_STR_LENGTH 100
typedef int (*dump_func)(const char *buffer, int size, void *data);
struct string
{
char *buffer;
int length;
int size;
};
static int dump_to_strbuffer(const char *buffer, int size, void *data)
{
return strbuffer_append_bytes((strbuffer_t *)data, buffer, size);
}
static int dump_to_file(const char *buffer, int size, void *data)
{
FILE *dest = (FILE *)data;
if(fwrite(buffer, size, 1, dest) != 1)
return -1;
return 0;
}
/* 256 spaces (the maximum indentation size) */
static char whitespace[] = " ";
static int dump_indent(unsigned long flags, int depth, int space, dump_func dump, void *data)
{
if(JSON_INDENT(flags) > 0)
{
int i, ws_count = JSON_INDENT(flags);
if(dump("\n", 1, data))
return -1;
for(i = 0; i < depth; i++)
{
if(dump(whitespace, ws_count, data))
return -1;
}
}
else if(space && !(flags & JSON_COMPACT))
{
return dump(" ", 1, data);
}
return 0;
}
static int dump_string(const char *str, int ascii, dump_func dump, void *data)
{
const char *pos, *end;
int32_t codepoint;
if(dump("\"", 1, data))
return -1;
end = pos = str;
while(1)
{
const char *text;
char seq[13];
int length;
while(*end)
{
end = utf8_iterate(pos, &codepoint);
if(!end)
return -1;
/* mandatory escape or control char */
if(codepoint == '\\' || codepoint == '"' || codepoint < 0x20)
break;
/* non-ASCII */
if(ascii && codepoint > 0x7F)
break;
pos = end;
}
if(pos != str) {
if(dump(str, pos - str, data))
return -1;
}
if(end == pos)
break;
/* handle \, ", and control codes */
length = 2;
switch(codepoint)
{
case '\\': text = "\\\\"; break;
case '\"': text = "\\\""; break;
case '\b': text = "\\b"; break;
case '\f': text = "\\f"; break;
case '\n': text = "\\n"; break;
case '\r': text = "\\r"; break;
case '\t': text = "\\t"; break;
default:
{
/* codepoint is in BMP */
if(codepoint < 0x10000)
{
sprintf(seq, "\\u%04x", codepoint);
length = 6;
}
/* not in BMP -> construct a UTF-16 surrogate pair */
else
{
int32_t first, last;
codepoint -= 0x10000;
first = 0xD800 | ((codepoint & 0xffc00) >> 10);
last = 0xDC00 | (codepoint & 0x003ff);
sprintf(seq, "\\u%04x\\u%04x", first, last);
length = 12;
}
text = seq;
break;
}
}
if(dump(text, length, data))
return -1;
str = pos = end;
}
return dump("\"", 1, data);
}
static int object_key_cmp(const void *key1, const void *key2)
{
return strcmp(*(const char **)key1, *(const char **)key2);
}
static int do_dump(const json_t *json, unsigned long flags, int depth,
dump_func dump, void *data)
{
int ascii = flags & JSON_ENSURE_ASCII ? 1 : 0;
switch(json_typeof(json)) {
case JSON_NULL:
return dump("null", 4, data);
case JSON_TRUE:
return dump("true", 4, data);
case JSON_FALSE:
return dump("false", 5, data);
case JSON_INTEGER:
{
char buffer[MAX_INTEGER_STR_LENGTH];
int size;
size = snprintf(buffer, MAX_INTEGER_STR_LENGTH, "%d", json_integer_value(json));
if(size >= MAX_INTEGER_STR_LENGTH)
return -1;
return dump(buffer, size, data);
}
case JSON_REAL:
{
char buffer[MAX_REAL_STR_LENGTH];
int size;
size = snprintf(buffer, MAX_REAL_STR_LENGTH, "%.17g",
json_real_value(json));
if(size >= MAX_REAL_STR_LENGTH)
return -1;
/* Make sure there's a dot or 'e' in the output. Otherwise
a real is converted to an integer when decoding */
if(strchr(buffer, '.') == NULL &&
strchr(buffer, 'e') == NULL)
{
if(size + 2 >= MAX_REAL_STR_LENGTH) {
/* No space to append ".0" */
return -1;
}
buffer[size] = '.';
buffer[size + 1] = '0';
size += 2;
}
return dump(buffer, size, data);
}
case JSON_STRING:
return dump_string(json_string_value(json), ascii, dump, data);
case JSON_ARRAY:
{
int i;
int n;
json_array_t *array;
/* detect circular references */
array = json_to_array(json);
if(array->visited)
return -1;
array->visited = 1;
n = json_array_size(json);
if(dump("[", 1, data))
return -1;
if(n == 0) {
array->visited = 0;
return dump("]", 1, data);
}
if(dump_indent(flags, depth + 1, 0, dump, data))
return -1;
for(i = 0; i < n; ++i) {
if(do_dump(json_array_get(json, i), flags, depth + 1,
dump, data))
return -1;
if(i < n - 1)
{
if(dump(",", 1, data) ||
dump_indent(flags, depth + 1, 1, dump, data))
return -1;
}
else
{
if(dump_indent(flags, depth, 0, dump, data))
return -1;
}
}
array->visited = 0;
return dump("]", 1, data);
}
case JSON_OBJECT:
{
json_object_t *object;
void *iter;
const char *separator;
int separator_length;
if(flags & JSON_COMPACT) {
separator = ":";
separator_length = 1;
}
else {
separator = ": ";
separator_length = 2;
}
/* detect circular references */
object = json_to_object(json);
if(object->visited)
return -1;
object->visited = 1;
iter = json_object_iter((json_t *)json);
if(dump("{", 1, data))
return -1;
if(!iter) {
object->visited = 0;
return dump("}", 1, data);
}
if(dump_indent(flags, depth + 1, 0, dump, data))
return -1;
if(flags & JSON_SORT_KEYS)
{
/* Sort keys */
const char **keys;
unsigned int size;
unsigned int i;
size = json_object_size(json);
keys = malloc(size * sizeof(const char *));
if(!keys)
return -1;
i = 0;
while(iter)
{
keys[i] = json_object_iter_key(iter);
iter = json_object_iter_next((json_t *)json, iter);
i++;
}
assert(i == size);
qsort(keys, size, sizeof(const char *), object_key_cmp);
for(i = 0; i < size; i++)
{
const char *key;
json_t *value;
key = keys[i];
value = json_object_get(json, key);
assert(value);
dump_string(key, ascii, dump, data);
if(dump(separator, separator_length, data) ||
do_dump(value, flags, depth + 1, dump, data))
{
free(keys);
return -1;
}
if(i < size - 1)
{
if(dump(",", 1, data) ||
dump_indent(flags, depth + 1, 1, dump, data))
{
free(keys);
return -1;
}
}
else
{
if(dump_indent(flags, depth, 0, dump, data))
{
free(keys);
return -1;
}
}
}
free(keys);
}
else
{
/* Don't sort keys */
while(iter)
{
void *next = json_object_iter_next((json_t *)json, iter);
dump_string(json_object_iter_key(iter), ascii, dump, data);
if(dump(separator, separator_length, data) ||
do_dump(json_object_iter_value(iter), flags, depth + 1,
dump, data))
return -1;
if(next)
{
if(dump(",", 1, data) ||
dump_indent(flags, depth + 1, 1, dump, data))
return -1;
}
else
{
if(dump_indent(flags, depth, 0, dump, data))
return -1;
}
iter = next;
}
}
object->visited = 0;
return dump("}", 1, data);
}
default:
/* not reached */
return -1;
}
}
char *json_dumps(const json_t *json, unsigned long flags)
{
strbuffer_t strbuff;
char *result;
if(!json_is_array(json) && !json_is_object(json))
return NULL;
if(strbuffer_init(&strbuff))
return NULL;
if(do_dump(json, flags, 0, dump_to_strbuffer, (void *)&strbuff)) {
strbuffer_close(&strbuff);
return NULL;
}
result = strdup(strbuffer_value(&strbuff));
strbuffer_close(&strbuff);
return result;
}
int json_dumpf(const json_t *json, FILE *output, unsigned long flags)
{
if(!json_is_array(json) && !json_is_object(json))
return -1;
return do_dump(json, flags, 0, dump_to_file, (void *)output);
}
int json_dump_file(const json_t *json, const char *path, unsigned long flags)
{
int result;
FILE *output = fopen(path, "w");
if(!output)
return -1;
result = json_dumpf(json, output, flags);
fclose(output);
return result;
}