contiki/apps/json/jsontree.c

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/*
* Copyright (c) 2011-2012, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*/
/**
* \file
* JSON output generation
* \author
* Niclas Finne <nfi@sics.se>
* Joakim Eriksson <joakime@sics.se>
*/
#include "contiki.h"
#include "jsontree.h"
#include "jsonparse.h"
#include <string.h>
#define DEBUG 0
#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif
/*---------------------------------------------------------------------------*/
void
jsontree_write_atom(const struct jsontree_context *js_ctx, const char *text)
{
if(text == NULL) {
js_ctx->putchar('0');
} else {
while(*text != '\0') {
js_ctx->putchar(*text++);
}
}
}
/*---------------------------------------------------------------------------*/
void
jsontree_write_string(const struct jsontree_context *js_ctx, const char *text)
{
js_ctx->putchar('"');
if(text != NULL) {
while(*text != '\0') {
if(*text == '"') {
js_ctx->putchar('\\');
}
js_ctx->putchar(*text++);
}
}
js_ctx->putchar('"');
}
/*---------------------------------------------------------------------------*/
void
jsontree_write_int(const struct jsontree_context *js_ctx, int value)
{
char buf[10];
int l;
if(value < 0) {
js_ctx->putchar('-');
value = -value;
}
l = sizeof(buf) - 1;
do {
buf[l--] = '0' + (value % 10);
value /= 10;
} while(value > 0 && l >= 0);
while(++l < sizeof(buf)) {
js_ctx->putchar(buf[l]);
}
}
/*---------------------------------------------------------------------------*/
void
jsontree_setup(struct jsontree_context *js_ctx, struct jsontree_value *root,
int (* putchar)(int))
{
js_ctx->values[0] = root;
js_ctx->putchar = putchar;
js_ctx->path = 0;
jsontree_reset(js_ctx);
}
/*---------------------------------------------------------------------------*/
void
jsontree_reset(struct jsontree_context *js_ctx)
{
js_ctx->depth = 0;
js_ctx->index[0] = 0;
}
/*---------------------------------------------------------------------------*/
const char *
jsontree_path_name(const struct jsontree_context *js_ctx, int depth)
{
if(depth < js_ctx->depth && js_ctx->values[depth]->type == JSON_TYPE_OBJECT) {
return ((struct jsontree_object *)js_ctx->values[depth])->
pairs[js_ctx->index[depth]].name;
}
return "";
}
/*---------------------------------------------------------------------------*/
int
jsontree_print_next(struct jsontree_context *js_ctx)
{
struct jsontree_value *v;
int index;
v = js_ctx->values[js_ctx->depth];
/* Default operation after switch is to back up one level */
switch(v->type) {
case JSON_TYPE_OBJECT:
case JSON_TYPE_ARRAY: {
struct jsontree_array *o = (struct jsontree_array *)v;
struct jsontree_value *ov;
index = js_ctx->index[js_ctx->depth];
if(index == 0) {
js_ctx->putchar(v->type);
js_ctx->putchar('\n');
}
if(index >= o->count) {
js_ctx->putchar('\n');
js_ctx->putchar(v->type + 2);
/* Default operation: back up one level! */
break;
}
if(index > 0) {
js_ctx->putchar(',');
js_ctx->putchar('\n');
}
if(v->type == JSON_TYPE_OBJECT) {
jsontree_write_string(js_ctx,
((struct jsontree_object *)o)->pairs[index].name);
js_ctx->putchar(':');
ov = ((struct jsontree_object *)o)->pairs[index].value;
} else {
ov = o->values[index];
}
/* TODO check max depth */
js_ctx->depth++; /* step down to value... */
js_ctx->index[js_ctx->depth] = 0; /* and init index */
js_ctx->values[js_ctx->depth] = ov;
/* Continue on this new level */
return 1;
}
case JSON_TYPE_STRING:
jsontree_write_string(js_ctx, ((struct jsontree_string *)v)->value);
/* Default operation: back up one level! */
break;
case JSON_TYPE_INT:
jsontree_write_int(js_ctx, ((struct jsontree_int *)v)->value);
/* Default operation: back up one level! */
break;
case JSON_TYPE_CALLBACK: { /* pre-formatted json string currently */
struct jsontree_callback *callback;
callback = (struct jsontree_callback *)v;
if(js_ctx->index[js_ctx->depth] == 0) {
/* First call: reset the callback status */
js_ctx->callback_state = 0;
}
if(callback->output == NULL) {
jsontree_write_string(js_ctx, "");
} else if(callback->output(js_ctx)) {
/* The callback wants to output more */
js_ctx->index[js_ctx->depth]++;
return 1;
}
/* Default operation: back up one level! */
break;
}
default:
PRINTF("\nError: Illegal json type:'%c'\n", v->type);
return 0;
}
/* Done => back up one level! */
if(js_ctx->depth > 0) {
js_ctx->depth--;
js_ctx->index[js_ctx->depth]++;
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/
static struct jsontree_value *
find_next(struct jsontree_context *js_ctx)
{
struct jsontree_value *v;
int index;
do {
v = js_ctx->values[js_ctx->depth];
/* Default operation after switch is to back up one level */
switch(v->type) {
case JSON_TYPE_OBJECT:
case JSON_TYPE_ARRAY: {
struct jsontree_array *o = (struct jsontree_array *)v;
struct jsontree_value *ov;
index = js_ctx->index[js_ctx->depth];
if(index >= o->count) {
/* Default operation: back up one level! */
break;
}
if(v->type == JSON_TYPE_OBJECT) {
ov = ((struct jsontree_object *)o)->pairs[index].value;
} else {
ov = o->values[index];
}
/* TODO check max depth */
js_ctx->depth++; /* step down to value... */
js_ctx->index[js_ctx->depth] = 0; /* and init index */
js_ctx->values[js_ctx->depth] = ov;
/* Continue on this new level */
return ov;
}
default:
/* Default operation: back up one level! */
break;
}
/* Done => back up one level! */
if(js_ctx->depth > 0) {
js_ctx->depth--;
js_ctx->index[js_ctx->depth]++;
} else {
return NULL;
}
} while(1);
}
/*---------------------------------------------------------------------------*/
struct jsontree_value *
jsontree_find_next(struct jsontree_context *js_ctx, int type)
{
struct jsontree_value *v;
while((v = find_next(js_ctx)) != NULL && v->type != type &&
js_ctx->path < js_ctx->depth) {
/* search */
}
js_ctx->callback_state = 0;
return js_ctx->path < js_ctx->depth ? v : NULL;
}
/*---------------------------------------------------------------------------*/