src/printer/json.c

/**
 * @file printer/json.c
 * @author Radek Krejci <rkrejci@cesnet.cz>
 * @brief JSON printer for libyang data structure
 *
 * Copyright (c) 2015 CESNET, z.s.p.o.
 *
 * 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 Company nor the names of its contributors
 *    may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <inttypes.h>

#include "../common.h"
#include "../xml.h"
#include "../tree.h"
#include "../resolve.h"
#include "../tree_internal.h"

#define INDENT ""
#define LEVEL (level*2)

void json_print_node(FILE *f, int level, struct lyd_node *node);

/* 0 - same, 1 - different */
static int
nscmp(struct lyd_node *node1, struct lyd_node *node2)
{
    struct lys_module *m1, *m2;

    /* we have to cover submodules belonging to the same module */
    if (node1->schema->module->type) {
        m1 = ((struct lys_submodule *)node1->schema->module)->belongsto;
    } else {
        m1 = node1->schema->module;
    }
    if (node2->schema->module->type) {
        m2 = ((struct lys_submodule *)node2->schema->module)->belongsto;
    } else {
        m2 = node2->schema->module;
    }
    if (m1 == m2) {
        /* belongs to the same module */
        return 0;
    } else {
        /* different modules */
        return 1;
    }
}

static void
json_print_text_dquote(FILE *f, const char *str, int str_len)
{
    const char *ptr;

    while ((ptr = strnchr(str, '\"', str_len))) {
        fprintf(f, "%.*s\\\"", (int)(ptr-str), str);
        str_len -= (ptr-str)+1;
        str = ptr+1;
    }

    fprintf(f, "%.*s", str_len, str);
}

static void
json_print_instid(FILE *f, struct lyd_node_leaf *leaf)
{
    const char *ptr, *print_ptr;
    int cur_id_len, print_id_len;
    struct unres_data *nodes, unres;
    struct lys_module *prev_module = NULL, *cur_module;
    struct lys_node *snode;

    assert(((struct lys_node_leaf *)leaf->schema)->type.base == LY_TYPE_INST);

    fputc('\"', f);
    print_ptr = ptr = leaf->value_str+1;

    while (print_ptr[0]) {
        fputc('/', f);

        /* check namespaces */
        ptr = strchr(ptr, '/');
        if (ptr) {
            cur_id_len = ptr - leaf->value_str;
        } else {
            cur_id_len = strlen(leaf->value_str);
        }

        memset(&unres, 0, sizeof unres);
        unres.dnode = (struct lyd_node *)leaf;
        resolve_instid(&unres, leaf->value_str, cur_id_len, &nodes);
        assert(nodes && !nodes->next);

        snode = (struct lys_node *)nodes->dnode->schema;
        free(nodes);

        /* find current module */
        if (snode->module->type) {
            cur_module = ((struct lys_submodule *)snode->module)->belongsto;
        } else {
            cur_module = snode->module;
        }

        if (!prev_module || (cur_module != prev_module)) {
            fprintf(f, "%s:", cur_module->ns);
            prev_module = cur_module;
        }

        ptr = strchr(print_ptr+1, '/');
        if (ptr) {
            print_id_len = ptr - print_ptr;
        } else {
            print_id_len = strlen(print_ptr);
        }

        json_print_text_dquote(f, print_ptr, print_id_len);
        print_ptr += print_id_len+1;
    }

    fprintf(f, "\"");
}

static void
json_print_leaf(FILE *f, int level, struct lyd_node *node, int onlyvalue)
{
    struct lyd_node_leaf *leaf = (struct lyd_node_leaf *)node;
    struct lys_node_leaf *sleaf = (struct lys_node_leaf *)node->schema;
    struct lys_type *type;
    LY_DATA_TYPE data_type;
    const char *schema;
    char dec[21];
    int i, len;

    if (!onlyvalue) {
        if (!node->parent || nscmp(node, node->parent)) {
            /* print "namespace" */
            if (node->schema->module->type) {
                /* submodule, get module */
                schema = ((struct lys_submodule *)node->schema->module)->belongsto->name;
            } else {
                schema = node->schema->module->name;
            }
            fprintf(f, "%*s\"%s:%s\": ", LEVEL, INDENT, schema, node->schema->name);
        } else {
            fprintf(f, "%*s\"%s\": ", LEVEL, INDENT, node->schema->name);
        }
    }

    data_type = ((struct lys_node_leaf *)leaf->schema)->type.base;
    if (data_type == LY_TYPE_UNION) {
        data_type = leaf->value_type;
    }

    switch (data_type) {
    case LY_TYPE_BINARY:
    case LY_TYPE_STRING:
        fprintf(f, "\"%s\"", leaf->value.string ? leaf->value.string : "");
        break;
    case LY_TYPE_BITS:
        fputc('"', f);

        /* locate bits structure with the bits definitions to get the array size */
        for (type = &sleaf->type; type->der->type.der; type = &type->der->type);

        /* print set bits */
        for (i = 0; i < type->info.bits.count; i++) {
            if (leaf->value.bit[i]) {
                fprintf(f, "%s%s", i ? " " : "", leaf->value.bit[i]->name);
            }
        }
        fputc('"', f);
        break;
    case LY_TYPE_BOOL:
        fprintf(f, "%s", leaf->value.bool ? "true" : "false");
        break;
    case LY_TYPE_DEC64:

        /* locate dec structure with the fraction-digits definitions to get the value */
        for (type = &sleaf->type; type->der->type.der; type = &type->der->type);

        snprintf(dec, 21, "%" PRId64, leaf->value.dec64);
        len = strlen(dec);
        for (i = 0; dec[i]; ) {
            fputc(dec[i++], f);
            if (i +  type->info.dec64.dig == len) {
                fputc('.', f);
            }
        }

        break;
    case LY_TYPE_EMPTY:
        fprintf(f, "[null]");
        break;
    case LY_TYPE_ENUM:
        fprintf(f, "\"%s\"", leaf->value.enm->name);
        break;
    case LY_TYPE_IDENT:
        if (sleaf->module != leaf->value.ident->module) {
            /* namespace identifier is needed */
            fprintf(f, "\"%s:%s\"", leaf->value.ident->module->name, leaf->value.ident->name);
        } else {
            /* no namespace is needed */
            fprintf(f, "\"%s\"", leaf->value.ident->name);
        }
        break;
    case LY_TYPE_INST:
        json_print_instid(f, leaf);
        break;
    case LY_TYPE_LEAFREF:
        json_print_leaf(f, level, leaf->value.leafref, 1);
        break;
    case LY_TYPE_INT8:
        fprintf(f, "%d", leaf->value.int8);
        break;
    case LY_TYPE_INT16:
        fprintf(f, "%d", leaf->value.int16);
        break;
    case LY_TYPE_INT32:
        fprintf(f, "%d", leaf->value.int32);
        break;
    case LY_TYPE_INT64:
        fprintf(f, "\"%ld\"", leaf->value.int64);
        break;
    case LY_TYPE_UINT8:
        fprintf(f, "%u", leaf->value.uint8);
        break;
    case LY_TYPE_UINT16:
        fprintf(f, "%u", leaf->value.uint16);
        break;
    case LY_TYPE_UINT32:
        fprintf(f, "%u", leaf->value.uint32);
        break;
    case LY_TYPE_UINT64:
        fprintf(f, "\"%lu\"", leaf->value.uint64);
        break;
    default:
        /* error */
        fprintf(f, "\"(!error!)\"");
    }

    if (!onlyvalue) {
        fprintf(f, "%s\n", lyd_is_last(node) ? "" : ",");
    }
}

static void
json_print_container(FILE *f, int level, struct lyd_node *node)
{
    const char *schema;
    struct lyd_node *child;

    if (!node->parent || nscmp(node, node->parent)) {
        /* print "namespace" */
        if (node->schema->module->type) {
            /* submodule, get module */
            schema = ((struct lys_submodule *)node->schema->module)->belongsto->name;
        } else {
            schema = node->schema->module->name;
        }
        fprintf(f, "%*s\"%s:%s\": {\n", LEVEL, INDENT, schema, node->schema->name);
    } else {
        fprintf(f, "%*s\"%s\": {\n", LEVEL, INDENT, node->schema->name);
    }
    LY_TREE_FOR(node->child, child) {
        json_print_node(f, level + 1, child);
    }
    fprintf(f, "%*s}%s\n", LEVEL, INDENT, lyd_is_last(node) ? "" : ",");
}

static void
json_print_list_internal(FILE *f, int level, struct lyd_node_list *list)
{
    struct lyd_node *child;

    fprintf(f, "%*s{\n", LEVEL, INDENT);

    LY_TREE_FOR(list->child, child) {
        json_print_node(f, level + 1, child);
    }

    fprintf(f, "%*s}%s\n", LEVEL, INDENT, (list->lnext ? "," : ""));
}

static void
json_print_leaf_list(FILE *f, int level, struct lyd_node *node, int is_list)
{
    const char *schema;
    struct lyd_node_list *list = (struct lyd_node_list *)node;
    struct lyd_node_leaflist *llist = (struct lyd_node_leaflist *)node;

    if ((is_list && list->lprev) || (!is_list && llist->lprev)) {
        /* this list is already printed */
        return;
    }

    if (!node->parent || nscmp(node, node->parent)) {
        /* print "namespace" */
        if (node->schema->module->type) {
            /* submodule, get module */
            schema = ((struct lys_submodule *)node->schema->module)->belongsto->name;
        } else {
            schema = node->schema->module->name;
        }
        fprintf(f, "%*s\"%s:%s\": [\n", LEVEL, INDENT, schema, node->schema->name);
    } else {
        fprintf(f, "%*s\"%s\": [\n", LEVEL, INDENT, node->schema->name);
    }

    if (!is_list) {
        ++level;
    }
    while ((is_list && list) || (!is_list &&  llist)) {
        if (is_list) {
            json_print_list_internal(f, level + 1, list);
            list = list->lnext;
        } else {
            fprintf(f, "%*s", LEVEL, INDENT);
            json_print_leaf(f, level, (struct lyd_node *)llist, 1);
            fprintf(f, "%s\n", (llist->lnext ? "," : ""));
            llist = llist->lnext;
        }
    }
    if (!is_list) {
        --level;
    }

    fprintf(f, "%*s]%s\n", LEVEL, INDENT, lyd_is_last(node) ? "" : ",");
}

static void
json_print_anyxml(FILE *f, int level, struct lyd_node *node)
{
    struct lyd_node_anyxml *axml = (struct lyd_node_anyxml *)node;

    fprintf(f, "%*s\"%s\": [null]%s\n", LEVEL, INDENT, axml->value->name, lyd_is_last(node) ? "" : ",");
}

void
json_print_node(FILE *f, int level, struct lyd_node *node)
{
    switch (node->schema->nodetype) {
    case LYS_CONTAINER:
        json_print_container(f, level, node);
        break;
    case LYS_LEAF:
        json_print_leaf(f, level, node, 0);
        break;
    case LYS_LEAFLIST:
        json_print_leaf_list(f, level, node, 0);
        break;
    case LYS_LIST:
        json_print_leaf_list(f, level, node, 1);
        break;
    case LYS_ANYXML:
        json_print_anyxml(f, level, node);
        break;
    default:
        assert(0);
        break;
    }
}

API int
json_print_data(FILE *f, struct lyd_node *root)
{
    int level = 0;
    struct lyd_node *node;

    /* start */
    fprintf(f, "{\n");

    /* content */
    LY_TREE_FOR(root, node) {
        json_print_node(f, level + 1, node);
    }

    /* end */
    fprintf(f, "}\n");

    return EXIT_SUCCESS;
}