parser.h

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/* Spa */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */
 
#ifndef SPA_POD_PARSER_H
#define SPA_POD_PARSER_H
 
#include <errno.h>
#include <stdarg.h>
 
#include <spa/pod/body.h>
#include <spa/pod/vararg.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
#ifndef SPA_API_POD_PARSER
 #ifdef SPA_API_IMPL
  #define SPA_API_POD_PARSER SPA_API_IMPL
 #else
  #define SPA_API_POD_PARSER static inline
 #endif
#endif
 
struct spa_pod_parser_state {
        uint32_t offset;
        uint32_t flags;
        struct spa_pod_frame *frame;
};
 
struct spa_pod_parser {
        const void *data;
        uint32_t size;
        uint32_t _padding;
        struct spa_pod_parser_state state;
};
 
#define SPA_POD_PARSER_INIT(buffer,size)  ((struct spa_pod_parser){ (buffer), (size), 0, {0,0,NULL}})
 
SPA_API_POD_PARSER void spa_pod_parser_init(struct spa_pod_parser *parser,
                                       const void *data, uint32_t size)
{
        *parser = SPA_POD_PARSER_INIT(data, size);
}
 
SPA_API_POD_PARSER void spa_pod_parser_pod(struct spa_pod_parser *parser,
                                      const struct spa_pod *pod)
{
        spa_pod_parser_init(parser, pod, SPA_POD_SIZE(pod));
}
 
SPA_API_POD_PARSER void spa_pod_parser_init_pod_body(struct spa_pod_parser *parser,
              const struct spa_pod *pod, const void *body)
{
        spa_pod_parser_init(parser,
                        SPA_PTROFF(body, -sizeof(struct spa_pod), const struct spa_pod),
                        pod->size + sizeof(struct spa_pod));
}
SPA_API_POD_PARSER void spa_pod_parser_init_from_data(struct spa_pod_parser *parser,
                const void *data, uint32_t maxsize, uint32_t offset, uint32_t size)
{
        size_t offs, sz;
        offs = SPA_MIN(offset, maxsize);
        sz = SPA_MIN(maxsize - offs, size);
        spa_pod_parser_init(parser, SPA_PTROFF(data, offs, void), sz);
}
 
SPA_API_POD_PARSER void
spa_pod_parser_get_state(struct spa_pod_parser *parser, struct spa_pod_parser_state *state)
{
        *state = parser->state;
}
 
SPA_API_POD_PARSER void
spa_pod_parser_reset(struct spa_pod_parser *parser, struct spa_pod_parser_state *state)
{
        parser->state = *state;
}
 
SPA_API_POD_PARSER int
spa_pod_parser_read_header(struct spa_pod_parser *parser, uint32_t offset, uint32_t size,
                void *header, uint32_t header_size, uint32_t pod_offset, const void **body)
{
        /* Cast to uint64_t to avoid wraparound. */
        const uint64_t long_offset = (uint64_t)offset + header_size;
        if (long_offset <= size && (offset & 7) == 0) {
                struct spa_pod *pod;
                /* a barrier around the memcpy to make sure it is not moved around or
                 * duplicated after the size check below. We need to work on shared
                 * memory and so there could be updates happening while we read. */
                SPA_BARRIER;
                memcpy(header, SPA_PTROFF(parser->data, offset, void), header_size);
                SPA_BARRIER;
                pod = SPA_PTROFF(header, pod_offset, struct spa_pod);
                /* Check that the size (rounded to the next multiple of 8) is in bounds. */
                if (long_offset + SPA_ROUND_UP_N((uint64_t)pod->size, SPA_POD_ALIGN) <= size) {
                        *body = SPA_PTROFF(parser->data, long_offset, void);
                        return 0;
                }
        }
        return -EPIPE;
}
 
SPA_API_POD_PARSER struct spa_pod *
spa_pod_parser_deref(struct spa_pod_parser *parser, uint32_t offset, uint32_t size)
{
        struct spa_pod pod;
        const void *body;
        if (spa_pod_parser_read_header(parser, offset, size, &pod, sizeof(pod), 0, &body) < 0)
                return NULL;
        return SPA_PTROFF(body, -sizeof(pod), struct spa_pod);
}
 
SPA_API_POD_PARSER struct spa_pod *spa_pod_parser_frame(struct spa_pod_parser *parser, struct spa_pod_frame *frame)
{
        return SPA_PTROFF(parser->data, frame->offset, struct spa_pod);
}
 
SPA_API_POD_PARSER void spa_pod_parser_push(struct spa_pod_parser *parser,
                      struct spa_pod_frame *frame, const struct spa_pod *pod, uint32_t offset)
{
        frame->pod = *pod;
        frame->offset = offset;
        frame->parent = parser->state.frame;
        frame->flags = parser->state.flags;
        parser->state.frame = frame;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_header(struct spa_pod_parser *parser,
                void *header, uint32_t header_size, uint32_t pod_offset, const void **body)
{
        struct spa_pod_frame *f = parser->state.frame;
        uint32_t size = f ? f->offset + SPA_POD_SIZE(&f->pod) : parser->size;
        return spa_pod_parser_read_header(parser, parser->state.offset, size,
                        header, header_size, pod_offset, body);
}
 
SPA_API_POD_PARSER int spa_pod_parser_current_body(struct spa_pod_parser *parser,
                struct spa_pod *pod, const void **body)
{
        return spa_pod_parser_get_header(parser, pod, sizeof(struct spa_pod), 0, body);
}
 
SPA_API_POD_PARSER struct spa_pod *spa_pod_parser_current(struct spa_pod_parser *parser)
{
        struct spa_pod pod;
        const void *body;
        if (spa_pod_parser_current_body(parser, &pod, &body) < 0)
                return NULL;
        return SPA_PTROFF(body, -sizeof(struct spa_pod), struct spa_pod);
}
 
SPA_API_POD_PARSER void spa_pod_parser_advance(struct spa_pod_parser *parser, const struct spa_pod *pod)
{
        parser->state.offset += SPA_ROUND_UP_N(SPA_POD_SIZE(pod), SPA_POD_ALIGN);
}
 
SPA_API_POD_PARSER int spa_pod_parser_next_body(struct spa_pod_parser *parser,
                struct spa_pod *pod, const void **body)
{
        if (spa_pod_parser_current_body(parser, pod, body) < 0)
                return -EINVAL;
        spa_pod_parser_advance(parser, pod);
        return 0;
}
 
SPA_API_POD_PARSER struct spa_pod *spa_pod_parser_next(struct spa_pod_parser *parser)
{
        struct spa_pod pod;
        const void *body;
        if (spa_pod_parser_current_body(parser, &pod, &body) < 0)
                return NULL;
        spa_pod_parser_advance(parser, &pod);
        return SPA_PTROFF(body, -sizeof(struct spa_pod), struct spa_pod);
}
 
SPA_API_POD_PARSER void spa_pod_parser_restart(struct spa_pod_parser *parser,
                      struct spa_pod_frame *frame)
{
        parser->state.offset = frame->offset;
}
 
SPA_API_POD_PARSER void spa_pod_parser_unpush(struct spa_pod_parser *parser,
                      struct spa_pod_frame *frame)
{
        spa_pod_parser_restart(parser, frame);
        parser->state.frame = frame->parent;
}
 
SPA_API_POD_PARSER int spa_pod_parser_pop(struct spa_pod_parser *parser,
                      struct spa_pod_frame *frame)
{
        spa_pod_parser_unpush(parser, frame);
        spa_pod_parser_advance(parser, &frame->pod);
        return 0;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_bool(struct spa_pod_parser *parser, bool *value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_bool(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_id(struct spa_pod_parser *parser, uint32_t *value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_id(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_int(struct spa_pod_parser *parser, int32_t *value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_int(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_long(struct spa_pod_parser *parser, int64_t *value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_long(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_float(struct spa_pod_parser *parser, float *value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_float(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_double(struct spa_pod_parser *parser, double *value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_double(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_string(struct spa_pod_parser *parser, const char **value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_string(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_bytes(struct spa_pod_parser *parser, const void **value, uint32_t *len)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_bytes(&pod, body, value, len)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_pointer(struct spa_pod_parser *parser, uint32_t *type, const void **value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_pointer(&pod, body, type, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_fd(struct spa_pod_parser *parser, int64_t *value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_fd(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_rectangle(struct spa_pod_parser *parser, struct spa_rectangle *value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_rectangle(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_fraction(struct spa_pod_parser *parser, struct spa_fraction *value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_fraction(&pod, body, value)) >= 0)
                spa_pod_parser_advance(parser, &pod);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_pod_body(struct spa_pod_parser *parser,
                struct spa_pod *value, const void **body)
{
        int res;
        if ((res = spa_pod_parser_current_body(parser, value, body)) < 0)
                return res;
        spa_pod_parser_advance(parser, value);
        return 0;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_pod(struct spa_pod_parser *parser, struct spa_pod **value)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_get_pod_body(parser, &pod, &body)) < 0)
                return res;
        *value = SPA_PTROFF(body, -sizeof(struct spa_pod), struct spa_pod);
        return 0;
}
 
SPA_API_POD_PARSER int spa_pod_parser_init_struct_body(struct spa_pod_parser *parser,
                struct spa_pod_frame *frame, const struct spa_pod *pod, const void *body)
{
        if (!spa_pod_is_struct(pod))
                return -EINVAL;
        spa_pod_parser_init_pod_body(parser, pod, body);
        spa_pod_parser_push(parser, frame, pod, parser->state.offset);
        parser->state.offset += sizeof(struct spa_pod_struct);
        return 0;
}
 
SPA_API_POD_PARSER int spa_pod_parser_push_struct_body(struct spa_pod_parser *parser,
                struct spa_pod_frame *frame, struct spa_pod *str, const void **str_body)
{
        int res;
        if ((res = spa_pod_parser_current_body(parser, str, str_body)) < 0)
                return res;
        if (!spa_pod_is_struct(str))
                return -EINVAL;
        spa_pod_parser_push(parser, frame, str, parser->state.offset);
        parser->state.offset += sizeof(struct spa_pod_struct);
        return 0;
}
SPA_API_POD_PARSER int spa_pod_parser_push_struct(struct spa_pod_parser *parser,
                struct spa_pod_frame *frame)
{
        struct spa_pod pod;
        const void *body;
        return spa_pod_parser_push_struct_body(parser, frame, &pod, &body);
}
 
SPA_API_POD_PARSER int spa_pod_parser_init_object_body(struct spa_pod_parser *parser,
                struct spa_pod_frame *frame, const struct spa_pod *pod, const void *body,
                struct spa_pod_object *object, const void **object_body)
{
        int res;
        if (!spa_pod_is_object(pod))
                return -EINVAL;
        spa_pod_parser_init_pod_body(parser, pod, body);
        if ((res = spa_pod_body_get_object(pod, body, object, object_body)) < 0)
                return res;
        spa_pod_parser_push(parser, frame, pod, parser->state.offset);
        parser->state.offset += sizeof(struct spa_pod_object);
        return 0;
}
 
SPA_API_POD_PARSER int spa_pod_parser_push_object_body(struct spa_pod_parser *parser,
                struct spa_pod_frame *frame, struct spa_pod_object *object, const void **object_body)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_object(&pod, body, object, object_body)) < 0)
                return res;
        spa_pod_parser_push(parser, frame, &pod, parser->state.offset);
        parser->state.offset += sizeof(struct spa_pod_object);
        return 0;
}
SPA_API_POD_PARSER int spa_pod_parser_push_object(struct spa_pod_parser *parser,
                struct spa_pod_frame *frame, uint32_t type, uint32_t *id)
{
        int res;
        struct spa_pod_object obj;
        const void *obj_body;
        if ((res = spa_pod_parser_push_object_body(parser, frame, &obj, &obj_body)) < 0)
                return res;
        if (type != obj.body.type) {
                spa_pod_parser_unpush(parser, frame);
                return -EPROTO;
        }
        if (id != NULL)
                *id = obj.body.id;
        return 0;
}
SPA_API_POD_PARSER int spa_pod_parser_get_prop_body(struct spa_pod_parser *parser,
                struct spa_pod_prop *prop, const void **body)
{
        int res;
        if ((res = spa_pod_parser_get_header(parser, prop,
                        sizeof(struct spa_pod_prop),
                        offsetof(struct spa_pod_prop, value), body)) >= 0)
                parser->state.offset += SPA_ROUND_UP_N(SPA_POD_PROP_SIZE(prop), SPA_POD_ALIGN);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_push_sequence_body(struct spa_pod_parser *parser,
                struct spa_pod_frame *frame, struct spa_pod_sequence *seq, const void **seq_body)
{
        int res;
        struct spa_pod pod;
        const void *body;
        if ((res = spa_pod_parser_current_body(parser, &pod, &body)) < 0)
                return res;
        if ((res = spa_pod_body_get_sequence(&pod, body, seq, seq_body)) < 0)
                return res;
        spa_pod_parser_push(parser, frame, &pod, parser->state.offset);
        parser->state.offset += sizeof(struct spa_pod_sequence);
        return 0;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get_control_body(struct spa_pod_parser *parser,
                struct spa_pod_control *control, const void **body)
{
        int res;
        if ((res = spa_pod_parser_get_header(parser, control,
                        sizeof(struct spa_pod_control),
                        offsetof(struct spa_pod_control, value), body)) >= 0)
                parser->state.offset += SPA_ROUND_UP_N(SPA_POD_CONTROL_SIZE(control), SPA_POD_ALIGN);
        return res;
}
 
SPA_API_POD_PARSER int spa_pod_parser_object_find_prop(struct spa_pod_parser *parser,
                uint32_t key, struct spa_pod_prop *prop, const void **body)
{
        uint32_t start_offset;
        struct spa_pod_frame *f = parser->state.frame;
 
        if (f == NULL || f->pod.type != SPA_TYPE_Object)
                return -EINVAL;
 
        start_offset = f->offset;
        while (spa_pod_parser_get_prop_body(parser, prop, body) >= 0) {
                if (prop->key == key)
                        return 0;
        }
        spa_pod_parser_restart(parser, f);
        parser->state.offset += sizeof(struct spa_pod_object);
        while (parser->state.offset != start_offset &&
               spa_pod_parser_get_prop_body(parser, prop, body) >= 0) {
                if (prop->key == key)
                        return 0;
        }
        *body = NULL;
        return -ENOENT;
}
 
SPA_API_POD_PARSER bool spa_pod_parser_body_can_collect(const struct spa_pod *pod, const void *body, char type)
{
        struct spa_pod_choice choice;
 
        if (pod == NULL)
                return false;
 
        if (pod->type == SPA_TYPE_Choice) {
                if (!spa_pod_is_choice(pod))
                        return false;
                if (type == 'V' || type == 'W')
                        return true;
                if (spa_pod_body_get_choice(pod, body, &choice, &body) < 0)
                        return false;
                if (choice.body.type != SPA_CHOICE_None)
                        return false;
                pod = &choice.body.child;
        }
 
        switch (type) {
        case 'P':
        case 'Q':
                return true;
        case 'b':
                return spa_pod_is_bool(pod);
        case 'I':
                return spa_pod_is_id(pod);
        case 'i':
                return spa_pod_is_int(pod);
        case 'l':
                return spa_pod_is_long(pod);
        case 'f':
                return spa_pod_is_float(pod);
        case 'd':
                return spa_pod_is_double(pod);
        case 's':
                return spa_pod_is_string(pod) || spa_pod_is_none(pod);
        case 'S':
                return spa_pod_is_string(pod);
        case 'y':
                return spa_pod_is_bytes(pod);
        case 'R':
                return spa_pod_is_rectangle(pod);
        case 'F':
                return spa_pod_is_fraction(pod);
        case 'B':
                return spa_pod_is_bitmap(pod);
        case 'a':
                return spa_pod_is_array(pod);
        case 'p':
                return spa_pod_is_pointer(pod);
        case 'h':
                return spa_pod_is_fd(pod);
        case 'T':
        case 'U':
                return spa_pod_is_struct(pod) || spa_pod_is_none(pod);
        case 'N':
        case 'O':
                return spa_pod_is_object(pod) || spa_pod_is_none(pod);
        case 'V':
        case 'W':
        default:
                return false;
        }
}
SPA_API_POD_PARSER bool spa_pod_parser_can_collect(const struct spa_pod *pod, char type)
{
        return spa_pod_parser_body_can_collect(pod, SPA_POD_BODY_CONST(pod), type);
}
 
#define SPA_POD_PARSER_COLLECT_BODY(_pod,_body,_type,args)                              \
({                                                                                      \
        int res = 0;                                                                    \
        struct spa_pod_choice choice;                                                   \
        const struct spa_pod *_p = _pod;                                                \
        const void *_b = _body;                                                         \
        if (_p->type == SPA_TYPE_Choice && _type != 'V' && _type != 'W') {              \
                if (spa_pod_body_get_choice(_p, _b, &choice, &_b) >= 0 &&               \
                    choice.body.type == SPA_CHOICE_None)                                \
                        _p = &choice.body.child;                                        \
        }                                                                               \
        switch (_type) {                                                                \
        case 'b':                                                                       \
        {                                                                               \
                bool *val = va_arg(args, bool*);                                        \
                res = spa_pod_body_get_bool(_p, _b, val);                               \
                break;                                                                  \
        }                                                                               \
        case 'I':                                                                       \
        {                                                                               \
                uint32_t *val = va_arg(args, uint32_t*);                                \
                res = spa_pod_body_get_id(_p, _b, val);                                 \
                break;                                                                  \
        }                                                                               \
        case 'i':                                                                       \
        {                                                                               \
                int32_t *val = va_arg(args, int32_t*);                                  \
                res = spa_pod_body_get_int(_p, _b, val);                                \
                break;                                                                  \
        }                                                                               \
        case 'l':                                                                       \
        {                                                                               \
                int64_t *val = va_arg(args, int64_t*);                                  \
                res = spa_pod_body_get_long(_p, _b, val);                               \
                break;                                                                  \
        }                                                                               \
        case 'f':                                                                       \
        {                                                                               \
                float *val = va_arg(args, float*);                                      \
                res = spa_pod_body_get_float(_p, _b, val);                              \
                break;                                                                  \
        }                                                                               \
        case 'd':                                                                       \
        {                                                                               \
                double *val = va_arg(args, double*);                                    \
                res = spa_pod_body_get_double(_p, _b, val);                             \
                break;                                                                  \
        }                                                                               \
        case 's':                                                                       \
        {                                                                               \
                const char **dest = va_arg(args, const char**);                         \
                if (_p->type == SPA_TYPE_None)                                  \
                        *dest = NULL;                                                   \
                else                                                                    \
                        res = spa_pod_body_get_string(_p, _b, dest);                    \
                break;                                                                  \
        }                                                                               \
        case 'S':                                                                       \
        {                                                                               \
                char *dest = va_arg(args, char*);                                       \
                uint32_t maxlen = va_arg(args, uint32_t);                               \
                res = spa_pod_body_copy_string(_p, _b, dest, maxlen);           \
                break;                                                                  \
        }                                                                               \
        case 'y':                                                                       \
        {                                                                               \
                const void **value = va_arg(args, const void**);                        \
                uint32_t *len = va_arg(args, uint32_t*);                                \
                res = spa_pod_body_get_bytes(_p, _b, value, len);                       \
                break;                                                                  \
        }                                                                               \
        case 'R':                                                                       \
        {                                                                               \
                struct spa_rectangle *val = va_arg(args, struct spa_rectangle*);        \
                res = spa_pod_body_get_rectangle(_p, _b, val);                  \
                break;                                                                  \
        }                                                                               \
        case 'F':                                                                       \
        {                                                                               \
                struct spa_fraction *val = va_arg(args, struct spa_fraction*);          \
                res = spa_pod_body_get_fraction(_p, _b, val);                   \
                break;                                                                  \
        }                                                                               \
        case 'B':                                                                       \
        {                                                                               \
                const uint8_t **val = va_arg(args, const uint8_t**);                    \
                res = spa_pod_body_get_bitmap(_p, _b, val);                             \
                break;                                                                  \
        }                                                                               \
        case 'a':                                                                       \
        {                                                                               \
                uint32_t *val_size = va_arg(args, uint32_t*);                           \
                uint32_t *val_type = va_arg(args, uint32_t*);                           \
                uint32_t *n_values = va_arg(args, uint32_t*);                           \
                const void **arr_body = va_arg(args, const void**);                     \
                *arr_body = spa_pod_body_get_array_values(_p, _b,                       \
                                n_values, val_size, val_type);                          \
                if (*arr_body == NULL)                                                  \
                        res = -EINVAL;                                                  \
                break;                                                                  \
        }                                                                               \
        case 'p':                                                                       \
        {                                                                               \
                uint32_t *type = va_arg(args, uint32_t*);                               \
                const void **value = va_arg(args, const void**);                        \
                res = spa_pod_body_get_pointer(_p, _b, type, value);                    \
                break;                                                                  \
        }                                                                               \
        case 'h':                                                                       \
        {                                                                               \
                int64_t *val = va_arg(args, int64_t*);                                  \
                res = spa_pod_body_get_fd(_p, _b, val);                                 \
                break;                                                                  \
        }                                                                               \
        default:                                                                        \
        {                                                                               \
                bool valid = false, do_body = false;                                    \
                switch (_type) {                                                        \
                case 'Q':                                                               \
                        do_body = true;                                                 \
                        SPA_FALLTHROUGH;                                                \
                case 'P':                                                               \
                        valid = true;                                                   \
                        break;                                                          \
                case 'U':                                                               \
                        do_body = true;                                                 \
                        SPA_FALLTHROUGH;                                                \
                case 'T':                                                               \
                        valid = spa_pod_is_struct(_p) || spa_pod_is_none(_p);           \
                        break;                                                          \
                case 'N':                                                               \
                        do_body = true;                                                 \
                        SPA_FALLTHROUGH;                                                \
                case 'O':                                                               \
                        valid = spa_pod_is_object(_p) || spa_pod_is_none(_p);           \
                        break;                                                          \
                case 'W':                                                               \
                        do_body = true;                                                 \
                        SPA_FALLTHROUGH;                                                \
                case 'V':                                                               \
                        valid = spa_pod_is_choice(_p) || spa_pod_is_none(_p);           \
                        break;                                                          \
                default:                                                                \
                        res = -EINVAL;                                                  \
                        break;                                                          \
                }                                                                       \
                if (res >= 0 && do_body) {                                              \
                        struct spa_pod *p = va_arg(args, struct spa_pod*);              \
                        const void **v = va_arg(args, const void **);                   \
                        if (valid && p && v) {                                          \
                                *p = *_p;                                               \
                                *v = _b;                                                \
                        }                                                               \
                } else if (res >= 0) {                                                  \
                        const struct spa_pod **d = va_arg(args, const struct spa_pod**);\
                        if (valid && d)                                                 \
                                *d = (_p->type == SPA_TYPE_None) ?                      \
                                        NULL :                                          \
                                        SPA_PTROFF((_b), -sizeof(struct spa_pod),       \
                                                const struct spa_pod);                  \
                }                                                                       \
                if (!valid)                                                             \
                        res = -EINVAL;                                                  \
                break;                                                                  \
        }                                                                               \
        }                                                                               \
        res;                                                                            \
})
 
#define SPA_POD_PARSER_COLLECT(pod,_type,args)                                          \
        SPA_POD_PARSER_COLLECT_BODY(pod, SPA_POD_BODY_CONST(pod),_type,args)
 
#define SPA_POD_PARSER_SKIP(_type,args)                                                 \
do {                                                                                    \
        switch (_type) {                                                                \
        case 'S':                                                                       \
                va_arg(args, char*);                                                    \
                va_arg(args, uint32_t);                                                 \
                break;                                                                  \
        case 'a':                                                                       \
                va_arg(args, void*);                                                    \
                va_arg(args, void*);                                                    \
                SPA_FALLTHROUGH                                                         \
        case 'p':                                                                       \
        case 'y':                                                                       \
                va_arg(args, void*);                                                    \
                SPA_FALLTHROUGH                                                         \
        case 'b':                                                                       \
        case 'I':                                                                       \
        case 'i':                                                                       \
        case 'l':                                                                       \
        case 'f':                                                                       \
        case 'd':                                                                       \
        case 's':                                                                       \
        case 'R':                                                                       \
        case 'F':                                                                       \
        case 'B':                                                                       \
        case 'h':                                                                       \
        case 'V':                                                                       \
        case 'P':                                                                       \
        case 'T':                                                                       \
        case 'O':                                                                       \
        case 'W':                                                                       \
        case 'Q':                                                                       \
        case 'U':                                                                       \
        case 'N':                                                                       \
                va_arg(args, void*);                                                    \
                break;                                                                  \
        }                                                                               \
} while(false)
 
SPA_API_POD_PARSER int spa_pod_parser_getv(struct spa_pod_parser *parser, va_list args)
{
        struct spa_pod_frame *f = parser->state.frame;
        int count = 0;
 
        if (f == NULL)
                return -EINVAL;
 
        do {
                bool optional;
                struct spa_pod pod = (struct spa_pod) { 0, SPA_TYPE_None };
                const void *body = NULL;
                const char *format;
                struct spa_pod_prop prop;
 
                if (f->pod.type == SPA_TYPE_Object) {
                        uint32_t key = va_arg(args, uint32_t), *flags = NULL;
 
                        if (key == 0)
                                break;
                        if (key == SPA_ID_INVALID) {
                                key = va_arg(args, uint32_t);
                                flags = va_arg(args, uint32_t*);
                        }
                        if (spa_pod_parser_object_find_prop(parser, key, &prop, &body) >= 0) {
                                pod = prop.value;
                                if (flags)
                                        *flags = prop.flags;
                        }
                }
 
                if ((format = va_arg(args, char *)) == NULL)
                        break;
 
                if (f->pod.type == SPA_TYPE_Struct)
                        spa_pod_parser_next_body(parser, &pod, &body);
 
                if ((optional = (*format == '?')))
                        format++;
 
                if (SPA_POD_PARSER_COLLECT_BODY(&pod, body, *format, args) >= 0) {
                        count++;
                } else if (!optional) {
                        if (body == NULL)
                                return -ESRCH;
                        else
                                return -EPROTO;
                }
        } while (true);
 
        return count;
}
 
SPA_API_POD_PARSER int spa_pod_parser_get(struct spa_pod_parser *parser, ...)
{
        int res;
        va_list args;
 
        va_start(args, parser);
        res = spa_pod_parser_getv(parser, args);
        va_end(args);
 
        return res;
}
 
#define SPA_POD_OPT_Bool(val)                           "?" SPA_POD_Bool(val)
#define SPA_POD_OPT_Id(val)                             "?" SPA_POD_Id(val)
#define SPA_POD_OPT_Int(val)                            "?" SPA_POD_Int(val)
#define SPA_POD_OPT_Long(val)                           "?" SPA_POD_Long(val)
#define SPA_POD_OPT_Float(val)                          "?" SPA_POD_Float(val)
#define SPA_POD_OPT_Double(val)                         "?" SPA_POD_Double(val)
#define SPA_POD_OPT_String(val)                         "?" SPA_POD_String(val)
#define SPA_POD_OPT_Stringn(val,len)                    "?" SPA_POD_Stringn(val,len)
#define SPA_POD_OPT_Bytes(val,len)                      "?" SPA_POD_Bytes(val,len)
#define SPA_POD_OPT_Rectangle(val)                      "?" SPA_POD_Rectangle(val)
#define SPA_POD_OPT_Fraction(val)                       "?" SPA_POD_Fraction(val)
#define SPA_POD_OPT_Array(csize,ctype,n_vals,vals)      "?" SPA_POD_Array(csize,ctype,n_vals,vals)
#define SPA_POD_OPT_Pointer(type,val)                   "?" SPA_POD_Pointer(type,val)
#define SPA_POD_OPT_Fd(val)                             "?" SPA_POD_Fd(val)
#define SPA_POD_OPT_Pod(val)                            "?" SPA_POD_Pod(val)
#define SPA_POD_OPT_PodObject(val)                      "?" SPA_POD_PodObject(val)
#define SPA_POD_OPT_PodStruct(val)                      "?" SPA_POD_PodStruct(val)
#define SPA_POD_OPT_PodChoice(val)                      "?" SPA_POD_PodChoice(val)
#define SPA_POD_OPT_PodBody(val,body)                   "?" SPA_POD_PodBody(val,body)
#define SPA_POD_OPT_PodBodyObject(val,body)             "?" SPA_POD_PodBodyObject(val,body)
#define SPA_POD_OPT_PodBodyStruct(val,body)             "?" SPA_POD_PodBodyStruct(val,body)
#define SPA_POD_OPT_PodBodyChoice(val,body)             "?" SPA_POD_PodBodyChoice(val,body)
 
#define spa_pod_parser_get_object(p,type,id,...)                                \
({                                                                              \
        struct spa_pod_frame _f;                                                \
        int _res;                                                               \
        if ((_res = spa_pod_parser_push_object(p, &_f, type, id)) == 0) {       \
                _res = spa_pod_parser_get(p,##__VA_ARGS__, 0);                  \
                spa_pod_parser_pop(p, &_f);                                     \
        }                                                                       \
        _res;                                                                   \
})
 
#define spa_pod_parser_get_struct(p,...)                                \
({                                                                      \
        struct spa_pod_frame _f;                                        \
        int _res;                                                       \
        if ((_res = spa_pod_parser_push_struct(p, &_f)) == 0) {         \
                _res = spa_pod_parser_get(p,##__VA_ARGS__, NULL);       \
                spa_pod_parser_pop(p, &_f);                             \
        }                                                               \
        _res;                                                   \
})
 
#define spa_pod_body_parse_object(pod,body,type,id,...)         \
({                                                              \
        struct spa_pod_parser _p;                               \
        spa_pod_parser_init_pod_body(&_p, pod, body);           \
        spa_pod_parser_get_object(&_p,type,id,##__VA_ARGS__);   \
})
 
#define spa_pod_parse_object(pod,type,id,...)           \
        spa_pod_body_parse_object(pod,SPA_POD_BODY_CONST(pod),type,id,##__VA_ARGS__)
 
#define spa_pod_body_parse_struct(pod,body,...)                 \
({                                                              \
        struct spa_pod_parser _p;                               \
        spa_pod_parser_init_pod_body(&_p, pod, body);           \
        spa_pod_parser_get_struct(&_p,##__VA_ARGS__);           \
})
 
#define spa_pod_parse_struct(pod,...)           \
        spa_pod_body_parse_struct(pod,SPA_POD_BODY_CONST(pod),##__VA_ARGS__)
#ifdef __cplusplus
}  /* extern "C" */
#endif
 
#endif /* SPA_POD_PARSER_H */