json.h

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/* Simple Plugin API */
/* SPDX-FileCopyrightText: Copyright © 2020 Wim Taymans */
/* SPDX-License-Identifier: MIT */
 
#ifndef SPA_UTILS_JSON_UTILS_H
#define SPA_UTILS_JSON_UTILS_H
 
#include <stddef.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <math.h>
#include <float.h>
 
#include <spa/utils/json-core.h>
 
#ifdef __cplusplus
extern "C" {
#else
#include <stdbool.h>
#endif
 
#ifndef SPA_API_JSON_UTILS
 #ifdef SPA_API_IMPL
  #define SPA_API_JSON_UTILS SPA_API_IMPL
 #else
  #define SPA_API_JSON_UTILS static inline
 #endif
#endif
 
SPA_API_JSON_UTILS int spa_json_begin(struct spa_json * iter, const char *data, size_t size, const char **val)
{
        spa_json_init(iter, data, size);
        return spa_json_next(iter, val);
}
 
/* float */
SPA_API_JSON_UTILS int spa_json_get_float(struct spa_json *iter, float *res)
{
        const char *value;
        int len;
        if ((len = spa_json_next(iter, &value)) <= 0)
                return len;
        return spa_json_parse_float(value, len, res);
}
 
/* int */
SPA_API_JSON_UTILS int spa_json_get_int(struct spa_json *iter, int *res)
{
        const char *value;
        int len;
        if ((len = spa_json_next(iter, &value)) <= 0)
                return len;
        return spa_json_parse_int(value, len, res);
}
 
/* bool */
SPA_API_JSON_UTILS int spa_json_get_bool(struct spa_json *iter, bool *res)
{
        const char *value;
        int len;
        if ((len = spa_json_next(iter, &value)) <= 0)
                return len;
        return spa_json_parse_bool(value, len, res);
}
 
/* string */
SPA_API_JSON_UTILS int spa_json_get_string(struct spa_json *iter, char *res, int maxlen)
{
        const char *value;
        int len;
        if ((len = spa_json_next(iter, &value)) <= 0)
                return len;
        return spa_json_parse_stringn(value, len, res, maxlen);
}
 
 
SPA_API_JSON_UTILS int spa_json_enter_container(struct spa_json *iter, struct spa_json *sub, char type)
{
        const char *value;
        int len;
        if ((len = spa_json_next(iter, &value)) <= 0)
                return len;
        if (!spa_json_is_container(value, len))
                return -EPROTO;
        if (*value != type)
                return -EINVAL;
        spa_json_enter(iter, sub);
        return 1;
}
 
SPA_API_JSON_UTILS int spa_json_begin_container(struct spa_json * iter,
                const char *data, size_t size, char type, bool relax)
{
        int res;
        spa_json_init(iter, data, size);
        res = spa_json_enter_container(iter, iter, type);
        if (res == -EPROTO && relax)
                spa_json_init(iter, data, size);
        else if (res <= 0)
                return res;
        return 1;
}
SPA_API_JSON_UTILS int spa_json_container_len(struct spa_json *iter, const char *value, int len SPA_UNUSED)
{
        const char *val;
        struct spa_json sub;
        int res;
        spa_json_enter(iter, &sub);
        while ((res = spa_json_next(&sub, &val)) > 0);
        if (res < 0)
                return 0;
        return sub.cur + 1 - value;
}
 
/* object */
SPA_API_JSON_UTILS int spa_json_enter_object(struct spa_json *iter, struct spa_json *sub)
{
        return spa_json_enter_container(iter, sub, '{');
}
SPA_API_JSON_UTILS int spa_json_begin_object_relax(struct spa_json * iter, const char *data, size_t size)
{
        return spa_json_begin_container(iter, data, size, '{', true);
}
SPA_API_JSON_UTILS int spa_json_begin_object(struct spa_json * iter, const char *data, size_t size)
{
        return spa_json_begin_container(iter, data, size, '{', false);
}
 
SPA_API_JSON_UTILS int spa_json_object_next(struct spa_json *iter, char *key, int maxkeylen, const char **value)
{
        int res1, res2;
        while (true) {
                res1 = spa_json_get_string(iter, key, maxkeylen);
                if (res1 <= 0 && res1 != -ENOSPC)
                        return res1;
                res2 = spa_json_next(iter, value);
                if (res2 <= 0 || res1 != -ENOSPC)
                        return res2;
        }
}
 
SPA_API_JSON_UTILS int spa_json_object_find(struct spa_json *iter, const char *key, const char **value)
{
        struct spa_json obj = SPA_JSON_SAVE(iter);
        int res, len = strlen(key) + 3;
        char k[len];
 
        while ((res = spa_json_object_next(&obj, k, len, value)) > 0)
                if (spa_streq(k, key))
                        return res;
        return -ENOENT;
}
 
SPA_API_JSON_UTILS int spa_json_str_object_find(const char *obj, size_t obj_len,
                const char *key, char *value, size_t maxlen)
{
        struct spa_json iter;
        int l;
        const char *v;
 
        if (spa_json_begin_object(&iter, obj, obj_len) <= 0)
                return -EINVAL;
        if ((l = spa_json_object_find(&iter, key, &v)) <= 0)
                return l;
        return spa_json_parse_stringn(v, l, value, maxlen);
}
 
/* array */
SPA_API_JSON_UTILS int spa_json_enter_array(struct spa_json *iter, struct spa_json *sub)
{
        return spa_json_enter_container(iter, sub, '[');
}
SPA_API_JSON_UTILS int spa_json_begin_array_relax(struct spa_json * iter, const char *data, size_t size)
{
        return spa_json_begin_container(iter, data, size, '[', true);
}
SPA_API_JSON_UTILS int spa_json_begin_array(struct spa_json * iter, const char *data, size_t size)
{
        return spa_json_begin_container(iter, data, size, '[', false);
}
 
#define spa_json_make_str_array_unpack(maxlen,type,conv)                        \
{                                                                               \
        struct spa_json iter;                                                   \
        char v[maxlen];                                                         \
        uint32_t count = 0;                                                     \
        if (spa_json_begin_array_relax(&iter, arr, arr_len) <= 0)               \
                return -EINVAL;                                                 \
        while (spa_json_get_string(&iter, v, sizeof(v)) > 0 && count < max)     \
                values[count++] = conv(v);                                      \
        return count;                                                           \
}
 
SPA_API_JSON_UTILS int spa_json_str_array_uint32(const char *arr, size_t arr_len,
                uint32_t *values, size_t max)
{
        spa_json_make_str_array_unpack(32,uint32_t, atoi);
}
 
#ifdef __cplusplus
} /* extern "C" */
#endif
 
#endif /* SPA_UTILS_JSON_UTILS_H */