src/java.desktop/unix/native/libpipewire/include/spa/pod/builder.h

/* Simple Plugin API */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */

#ifndef SPA_POD_BUILDER_H
#define SPA_POD_BUILDER_H

#ifdef __cplusplus
extern "C" {
#endif

/** \defgroup spa_pod POD
 * Binary data serialization format
 */

/**
 * \addtogroup spa_pod
 * \{
 */

#include <stdarg.h>

#include <spa/utils/hook.h>
#include <spa/pod/iter.h>
#include <spa/pod/vararg.h>

#ifndef SPA_API_POD_BUILDER
 #ifdef SPA_API_IMPL
  #define SPA_API_POD_BUILDER SPA_API_IMPL
 #else
  #define SPA_API_POD_BUILDER static inline
 #endif
#endif

struct spa_pod_builder_state {
    uint32_t offset;
#define SPA_POD_BUILDER_FLAG_BODY    (1<<0)
#define SPA_POD_BUILDER_FLAG_FIRST    (1<<1)
    uint32_t flags;
    struct spa_pod_frame *frame;
};

struct spa_pod_builder;

struct spa_pod_builder_callbacks {
#define SPA_VERSION_POD_BUILDER_CALLBACKS 0
    uint32_t version;

    int (*overflow) (void *data, uint32_t size);
};

struct spa_pod_builder {
    void *data;
    uint32_t size;
    uint32_t _padding;
    struct spa_pod_builder_state state;
    struct spa_callbacks callbacks;
};

#define SPA_POD_BUILDER_INIT(buffer,size)  ((struct spa_pod_builder){ (buffer), (size), 0, {0,0,NULL},{NULL,NULL}})

SPA_API_POD_BUILDER void
spa_pod_builder_get_state(struct spa_pod_builder *builder, struct spa_pod_builder_state *state)
{
    *state = builder->state;
}

SPA_API_POD_BUILDER void
spa_pod_builder_set_callbacks(struct spa_pod_builder *builder,
        const struct spa_pod_builder_callbacks *callbacks, void *data)
{
    builder->callbacks = SPA_CALLBACKS_INIT(callbacks, data);
}

SPA_API_POD_BUILDER void
spa_pod_builder_reset(struct spa_pod_builder *builder, struct spa_pod_builder_state *state)
{
    struct spa_pod_frame *f;
    uint32_t size = builder->state.offset - state->offset;
    builder->state = *state;
    for (f = builder->state.frame; f ; f = f->parent)
        f->pod.size -= size;
}

SPA_API_POD_BUILDER void spa_pod_builder_init(struct spa_pod_builder *builder, void *data, uint32_t size)
{
    *builder = SPA_POD_BUILDER_INIT(data, size);
}

SPA_API_POD_BUILDER struct spa_pod *
spa_pod_builder_deref(struct spa_pod_builder *builder, uint32_t offset)
{
    uint32_t size = builder->size;
    if (offset + 8 <= size) {
        struct spa_pod *pod = SPA_PTROFF(builder->data, offset, struct spa_pod);
        if (offset + SPA_POD_SIZE(pod) <= size)
            return pod;
    }
    return NULL;
}

SPA_API_POD_BUILDER struct spa_pod *
spa_pod_builder_frame(struct spa_pod_builder *builder, struct spa_pod_frame *frame)
{
    if (frame->offset + SPA_POD_SIZE(&frame->pod) <= builder->size)
        return SPA_PTROFF(builder->data, frame->offset, struct spa_pod);
    return NULL;
}

SPA_API_POD_BUILDER void
spa_pod_builder_push(struct spa_pod_builder *builder,
             struct spa_pod_frame *frame,
             const struct spa_pod *pod,
             uint32_t offset)
{
    frame->pod = *pod;
    frame->offset = offset;
    frame->parent = builder->state.frame;
    frame->flags = builder->state.flags;
    builder->state.frame = frame;

    if (frame->pod.type == SPA_TYPE_Array || frame->pod.type == SPA_TYPE_Choice)
        builder->state.flags = SPA_POD_BUILDER_FLAG_FIRST | SPA_POD_BUILDER_FLAG_BODY;
}

SPA_API_POD_BUILDER int spa_pod_builder_raw(struct spa_pod_builder *builder, const void *data, uint32_t size)
{
    int res = 0;
    struct spa_pod_frame *f;
    uint32_t offset = builder->state.offset;

    if (offset + size > builder->size) {
        res = -ENOSPC;
        if (offset <= builder->size)
            spa_callbacks_call_res(&builder->callbacks,
                    struct spa_pod_builder_callbacks, res,
                    overflow, 0, offset + size);
    }
    if (res == 0 && data)
        memcpy(SPA_PTROFF(builder->data, offset, void), data, size);

    builder->state.offset += size;

    for (f = builder->state.frame; f ; f = f->parent)
        f->pod.size += size;

    return res;
}

SPA_API_POD_BUILDER int spa_pod_builder_pad(struct spa_pod_builder *builder, uint32_t size)
{
    uint64_t zeroes = 0;
    size = SPA_ROUND_UP_N(size, 8) - size;
    return size ? spa_pod_builder_raw(builder, &zeroes, size) : 0;
}

SPA_API_POD_BUILDER int
spa_pod_builder_raw_padded(struct spa_pod_builder *builder, const void *data, uint32_t size)
{
    int r, res = spa_pod_builder_raw(builder, data, size);
    if ((r = spa_pod_builder_pad(builder, size)) < 0)
        res = r;
    return res;
}

SPA_API_POD_BUILDER void *spa_pod_builder_pop(struct spa_pod_builder *builder, struct spa_pod_frame *frame)
{
    struct spa_pod *pod;

    if (SPA_FLAG_IS_SET(builder->state.flags, SPA_POD_BUILDER_FLAG_FIRST)) {
        const struct spa_pod p = { 0, SPA_TYPE_None };
        spa_pod_builder_raw(builder, &p, sizeof(p));
    }
    if ((pod = (struct spa_pod*)spa_pod_builder_frame(builder, frame)) != NULL)
        *pod = frame->pod;

    builder->state.frame = frame->parent;
    builder->state.flags = frame->flags;
    spa_pod_builder_pad(builder, builder->state.offset);
    return pod;
}

SPA_API_POD_BUILDER int
spa_pod_builder_primitive(struct spa_pod_builder *builder, const struct spa_pod *p)
{
    const void *data;
    uint32_t size;
    int r, res;

    if (builder->state.flags == SPA_POD_BUILDER_FLAG_BODY) {
        data = SPA_POD_BODY_CONST(p);
        size = SPA_POD_BODY_SIZE(p);
    } else {
        data = p;
        size = SPA_POD_SIZE(p);
        SPA_FLAG_CLEAR(builder->state.flags, SPA_POD_BUILDER_FLAG_FIRST);
    }
    res = spa_pod_builder_raw(builder, data, size);
    if (builder->state.flags != SPA_POD_BUILDER_FLAG_BODY)
        if ((r = spa_pod_builder_pad(builder, size)) < 0)
            res = r;
    return res;
}

#define SPA_POD_INIT(size,type) ((struct spa_pod) { (size), (type) })

#define SPA_POD_INIT_None() SPA_POD_INIT(0, SPA_TYPE_None)

SPA_API_POD_BUILDER int spa_pod_builder_none(struct spa_pod_builder *builder)
{
    const struct spa_pod p = SPA_POD_INIT_None();
    return spa_pod_builder_primitive(builder, &p);
}

SPA_API_POD_BUILDER int spa_pod_builder_child(struct spa_pod_builder *builder, uint32_t size, uint32_t type)
{
    const struct spa_pod p = SPA_POD_INIT(size,type);
    SPA_FLAG_CLEAR(builder->state.flags, SPA_POD_BUILDER_FLAG_FIRST);
    return spa_pod_builder_raw(builder, &p, sizeof(p));
}

#define SPA_POD_INIT_Bool(val) ((struct spa_pod_bool){ { sizeof(uint32_t), SPA_TYPE_Bool }, (val) ? 1 : 0, 0 })

SPA_API_POD_BUILDER int spa_pod_builder_bool(struct spa_pod_builder *builder, bool val)
{
    const struct spa_pod_bool p = SPA_POD_INIT_Bool(val);
    return spa_pod_builder_primitive(builder, &p.pod);
}

#define SPA_POD_INIT_Id(val) ((struct spa_pod_id){ { sizeof(uint32_t), SPA_TYPE_Id }, (val), 0 })

SPA_API_POD_BUILDER int spa_pod_builder_id(struct spa_pod_builder *builder, uint32_t val)
{
    const struct spa_pod_id p = SPA_POD_INIT_Id(val);
    return spa_pod_builder_primitive(builder, &p.pod);
}

#define SPA_POD_INIT_Int(val) ((struct spa_pod_int){ { sizeof(int32_t), SPA_TYPE_Int }, (val), 0 })

SPA_API_POD_BUILDER int spa_pod_builder_int(struct spa_pod_builder *builder, int32_t val)
{
    const struct spa_pod_int p = SPA_POD_INIT_Int(val);
    return spa_pod_builder_primitive(builder, &p.pod);
}

#define SPA_POD_INIT_Long(val) ((struct spa_pod_long){ { sizeof(int64_t), SPA_TYPE_Long }, (val) })

SPA_API_POD_BUILDER int spa_pod_builder_long(struct spa_pod_builder *builder, int64_t val)
{
    const struct spa_pod_long p = SPA_POD_INIT_Long(val);
    return spa_pod_builder_primitive(builder, &p.pod);
}

#define SPA_POD_INIT_Float(val) ((struct spa_pod_float){ { sizeof(float), SPA_TYPE_Float }, (val), 0 })

SPA_API_POD_BUILDER int spa_pod_builder_float(struct spa_pod_builder *builder, float val)
{
    const struct spa_pod_float p = SPA_POD_INIT_Float(val);
    return spa_pod_builder_primitive(builder, &p.pod);
}

#define SPA_POD_INIT_Double(val) ((struct spa_pod_double){ { sizeof(double), SPA_TYPE_Double }, (val) })

SPA_API_POD_BUILDER int spa_pod_builder_double(struct spa_pod_builder *builder, double val)
{
    const struct spa_pod_double p = SPA_POD_INIT_Double(val);
    return spa_pod_builder_primitive(builder, &p.pod);
}

#define SPA_POD_INIT_String(len) ((struct spa_pod_string){ { (len), SPA_TYPE_String } })

SPA_API_POD_BUILDER int
spa_pod_builder_write_string(struct spa_pod_builder *builder, const char *str, uint32_t len)
{
    int r, res;
    res = spa_pod_builder_raw(builder, str, len);
    if ((r = spa_pod_builder_raw(builder, "", 1)) < 0)
        res = r;
    if ((r = spa_pod_builder_pad(builder, builder->state.offset)) < 0)
        res = r;
    return res;
}

SPA_API_POD_BUILDER int
spa_pod_builder_string_len(struct spa_pod_builder *builder, const char *str, uint32_t len)
{
    const struct spa_pod_string p = SPA_POD_INIT_String(len+1);
    int r, res = spa_pod_builder_raw(builder, &p, sizeof(p));
    if ((r = spa_pod_builder_write_string(builder, str, len)) < 0)
        res = r;
    return res;
}

SPA_API_POD_BUILDER int spa_pod_builder_string(struct spa_pod_builder *builder, const char *str)
{
    uint32_t len = str ? strlen(str) : 0;
    return spa_pod_builder_string_len(builder, str ? str : "", len);
}

#define SPA_POD_INIT_Bytes(len) ((struct spa_pod_bytes){ { (len), SPA_TYPE_Bytes } })

SPA_API_POD_BUILDER int
spa_pod_builder_bytes(struct spa_pod_builder *builder, const void *bytes, uint32_t len)
{
    const struct spa_pod_bytes p = SPA_POD_INIT_Bytes(len);
    int r, res = spa_pod_builder_raw(builder, &p, sizeof(p));
    if ((r = spa_pod_builder_raw_padded(builder, bytes, len)) < 0)
        res = r;
    return res;
}
SPA_API_POD_BUILDER void *
spa_pod_builder_reserve_bytes(struct spa_pod_builder *builder, uint32_t len)
{
    uint32_t offset = builder->state.offset;
    if (spa_pod_builder_bytes(builder, NULL, len) < 0)
        return NULL;
    return SPA_POD_BODY(spa_pod_builder_deref(builder, offset));
}

#define SPA_POD_INIT_Pointer(type,value) ((struct spa_pod_pointer){ { sizeof(struct spa_pod_pointer_body), SPA_TYPE_Pointer }, { (type), 0, (value) } })

SPA_API_POD_BUILDER int
spa_pod_builder_pointer(struct spa_pod_builder *builder, uint32_t type, const void *val)
{
    const struct spa_pod_pointer p = SPA_POD_INIT_Pointer(type, val);
    return spa_pod_builder_primitive(builder, &p.pod);
}

#define SPA_POD_INIT_Fd(fd) ((struct spa_pod_fd){ { sizeof(int64_t), SPA_TYPE_Fd }, (fd) })

SPA_API_POD_BUILDER int spa_pod_builder_fd(struct spa_pod_builder *builder, int64_t fd)
{
    const struct spa_pod_fd p = SPA_POD_INIT_Fd(fd);
    return spa_pod_builder_primitive(builder, &p.pod);
}

#define SPA_POD_INIT_Rectangle(val) ((struct spa_pod_rectangle){ { sizeof(struct spa_rectangle), SPA_TYPE_Rectangle }, (val) })

SPA_API_POD_BUILDER int
spa_pod_builder_rectangle(struct spa_pod_builder *builder, uint32_t width, uint32_t height)
{
    const struct spa_pod_rectangle p = SPA_POD_INIT_Rectangle(SPA_RECTANGLE(width, height));
    return spa_pod_builder_primitive(builder, &p.pod);
}

#define SPA_POD_INIT_Fraction(val) ((struct spa_pod_fraction){ { sizeof(struct spa_fraction), SPA_TYPE_Fraction }, (val) })

SPA_API_POD_BUILDER int
spa_pod_builder_fraction(struct spa_pod_builder *builder, uint32_t num, uint32_t denom)
{
    const struct spa_pod_fraction p = SPA_POD_INIT_Fraction(SPA_FRACTION(num, denom));
    return spa_pod_builder_primitive(builder, &p.pod);
}

SPA_API_POD_BUILDER int
spa_pod_builder_push_array(struct spa_pod_builder *builder, struct spa_pod_frame *frame)
{
    const struct spa_pod_array p =
        { {sizeof(struct spa_pod_array_body) - sizeof(struct spa_pod), SPA_TYPE_Array},
        {{0, 0}} };
    uint32_t offset = builder->state.offset;
    int res = spa_pod_builder_raw(builder, &p, sizeof(p) - sizeof(struct spa_pod));
    spa_pod_builder_push(builder, frame, &p.pod, offset);
    return res;
}

SPA_API_POD_BUILDER int
spa_pod_builder_array(struct spa_pod_builder *builder,
              uint32_t child_size, uint32_t child_type, uint32_t n_elems, const void *elems)
{
    const struct spa_pod_array p = {
        {(uint32_t)(sizeof(struct spa_pod_array_body) + n_elems * child_size), SPA_TYPE_Array},
        {{child_size, child_type}}
    };
    int r, res = spa_pod_builder_raw(builder, &p, sizeof(p));
    if ((r = spa_pod_builder_raw_padded(builder, elems, child_size * n_elems)) < 0)
        res = r;
    return res;
}

#define SPA_POD_INIT_CHOICE_BODY(type, flags, child_size, child_type)                \
    ((struct spa_pod_choice_body) { (type), (flags), { (child_size), (child_type) }})

#define SPA_POD_INIT_Choice(type, ctype, child_type, n_vals, ...)                \
    ((struct { struct spa_pod_choice choice; ctype vals[(n_vals)];})            \
    { { { (n_vals) * sizeof(ctype) + sizeof(struct spa_pod_choice_body), SPA_TYPE_Choice },    \
        { (type), 0, { sizeof(ctype), (child_type) } } }, { __VA_ARGS__ } })

SPA_API_POD_BUILDER int
spa_pod_builder_push_choice(struct spa_pod_builder *builder, struct spa_pod_frame *frame,
        uint32_t type, uint32_t flags)
{
    const struct spa_pod_choice p =
        { {sizeof(struct spa_pod_choice_body) - sizeof(struct spa_pod), SPA_TYPE_Choice},
        { type, flags, {0, 0}} };
    uint32_t offset = builder->state.offset;
    int res = spa_pod_builder_raw(builder, &p, sizeof(p) - sizeof(struct spa_pod));
    spa_pod_builder_push(builder, frame, &p.pod, offset);
    return res;
}

#define SPA_POD_INIT_Struct(size) ((struct spa_pod_struct){ { (size), SPA_TYPE_Struct } })

SPA_API_POD_BUILDER int
spa_pod_builder_push_struct(struct spa_pod_builder *builder, struct spa_pod_frame *frame)
{
    const struct spa_pod_struct p = SPA_POD_INIT_Struct(0);
    uint32_t offset = builder->state.offset;
    int res = spa_pod_builder_raw(builder, &p, sizeof(p));
    spa_pod_builder_push(builder, frame, &p.pod, offset);
    return res;
}

#define SPA_POD_INIT_Object(size,type,id,...)    ((struct spa_pod_object){ { (size), SPA_TYPE_Object }, { (type), (id) }, ##__VA_ARGS__ })

SPA_API_POD_BUILDER int
spa_pod_builder_push_object(struct spa_pod_builder *builder, struct spa_pod_frame *frame,
        uint32_t type, uint32_t id)
{
    const struct spa_pod_object p =
        SPA_POD_INIT_Object(sizeof(struct spa_pod_object_body), type, id);
    uint32_t offset = builder->state.offset;
    int res = spa_pod_builder_raw(builder, &p, sizeof(p));
    spa_pod_builder_push(builder, frame, &p.pod, offset);
    return res;
}

#define SPA_POD_INIT_Prop(key,flags,size,type)    \
    ((struct spa_pod_prop){ (key), (flags), { (size), (type) } })

SPA_API_POD_BUILDER int
spa_pod_builder_prop(struct spa_pod_builder *builder, uint32_t key, uint32_t flags)
{
    const struct { uint32_t key; uint32_t flags; } p = { key, flags };
    return spa_pod_builder_raw(builder, &p, sizeof(p));
}

#define SPA_POD_INIT_Sequence(size,unit)    \
    ((struct spa_pod_sequence){ { (size), SPA_TYPE_Sequence}, {(unit), 0 } })

SPA_API_POD_BUILDER int
spa_pod_builder_push_sequence(struct spa_pod_builder *builder, struct spa_pod_frame *frame, uint32_t unit)
{
    const struct spa_pod_sequence p =
        SPA_POD_INIT_Sequence(sizeof(struct spa_pod_sequence_body), unit);
    uint32_t offset = builder->state.offset;
    int res = spa_pod_builder_raw(builder, &p, sizeof(p));
    spa_pod_builder_push(builder, frame, &p.pod, offset);
    return res;
}

SPA_API_POD_BUILDER int
spa_pod_builder_control(struct spa_pod_builder *builder, uint32_t offset, uint32_t type)
{
    const struct { uint32_t offset; uint32_t type; } p = { offset, type };
    return spa_pod_builder_raw(builder, &p, sizeof(p));
}

SPA_API_POD_BUILDER uint32_t spa_choice_from_id(char id)
{
    switch (id) {
    case 'r':
        return SPA_CHOICE_Range;
    case 's':
        return SPA_CHOICE_Step;
    case 'e':
        return SPA_CHOICE_Enum;
    case 'f':
        return SPA_CHOICE_Flags;
    case 'n':
    default:
        return SPA_CHOICE_None;
    }
}

#define SPA_POD_BUILDER_COLLECT(builder,type,args)                \
do {                                        \
    switch (type) {                                \
    case 'b':                                \
        spa_pod_builder_bool(builder, !!va_arg(args, int));        \
        break;                                \
    case 'I':                                \
        spa_pod_builder_id(builder, va_arg(args, uint32_t));        \
        break;                                \
    case 'i':                                \
        spa_pod_builder_int(builder, va_arg(args, int));        \
        break;                                \
    case 'l':                                \
        spa_pod_builder_long(builder, va_arg(args, int64_t));        \
        break;                                \
    case 'f':                                \
        spa_pod_builder_float(builder, (float)va_arg(args, double));    \
        break;                                \
    case 'd':                                \
        spa_pod_builder_double(builder, va_arg(args, double));        \
        break;                                \
    case 's':                                \
    {                                    \
        char *strval = va_arg(args, char *);                \
        if (strval != NULL) {                        \
            size_t len = strlen(strval);                \
            spa_pod_builder_string_len(builder, strval, len);    \
        }                                \
        else                                \
            spa_pod_builder_none(builder);                \
        break;                                \
    }                                    \
    case 'S':                                \
    {                                    \
        char *strval = va_arg(args, char *);                \
        size_t len = va_arg(args, int);                    \
        spa_pod_builder_string_len(builder, strval, len);        \
        break;                                \
    }                                    \
    case 'y':                                \
    {                                    \
        void *ptr  = va_arg(args, void *);                \
        int len = va_arg(args, int);                    \
        spa_pod_builder_bytes(builder, ptr, len);            \
        break;                                \
    }                                    \
    case 'R':                                \
    {                                    \
        struct spa_rectangle *rectval =                    \
            va_arg(args, struct spa_rectangle *);            \
        spa_pod_builder_rectangle(builder,                \
                rectval->width, rectval->height);        \
        break;                                \
    }                                    \
    case 'F':                                \
    {                                    \
        struct spa_fraction *fracval =                    \
            va_arg(args, struct spa_fraction *);            \
        spa_pod_builder_fraction(builder, fracval->num, fracval->denom);\
        break;                                \
    }                                    \
    case 'a':                                \
    {                                    \
        int child_size = va_arg(args, int);                \
        int child_type = va_arg(args, int);                \
        int n_elems = va_arg(args, int);                \
        void *elems = va_arg(args, void *);                \
        spa_pod_builder_array(builder, child_size,            \
                child_type, n_elems, elems);            \
        break;                                \
    }                                    \
    case 'p':                                \
    {                                    \
        int t = va_arg(args, uint32_t);                    \
        spa_pod_builder_pointer(builder, t, va_arg(args, void *));    \
        break;                                \
    }                                    \
    case 'h':                                \
        spa_pod_builder_fd(builder, va_arg(args, int));            \
        break;                                \
    case 'P':                                \
    case 'O':                                \
    case 'T':                                \
    case 'V':                                \
    {                                    \
        struct spa_pod *pod = va_arg(args, struct spa_pod *);        \
        if (pod == NULL)                        \
            spa_pod_builder_none(builder);                \
        else                                \
            spa_pod_builder_primitive(builder, pod);        \
        break;                                \
    }                                    \
    }                                    \
} while(false)

SPA_API_POD_BUILDER int
spa_pod_builder_addv(struct spa_pod_builder *builder, va_list args)
{
    int res = 0;
    struct spa_pod_frame *frame = builder->state.frame;
    uint32_t ftype = frame ? frame->pod.type : (uint32_t)SPA_TYPE_None;

    do {
        const char *format;
        int n_values = 1;
        struct spa_pod_frame f;
        bool choice;

        switch (ftype) {
        case SPA_TYPE_Object:
        {
            uint32_t key = va_arg(args, uint32_t);
            if (key == 0)
                goto exit;
            spa_pod_builder_prop(builder, key, 0);
            break;
        }
        case SPA_TYPE_Sequence:
        {
            uint32_t offset = va_arg(args, uint32_t);
            uint32_t type = va_arg(args, uint32_t);
            if (type == 0)
                goto exit;
            spa_pod_builder_control(builder, offset, type);
            SPA_FALLTHROUGH
        }
        default:
            break;
        }
        if ((format = va_arg(args, const char *)) == NULL)
            break;

        choice = *format == '?';
        if (choice) {
            uint32_t type = spa_choice_from_id(*++format);
            if (*format != '\0')
                format++;

            spa_pod_builder_push_choice(builder, &f, type, 0);

            n_values = va_arg(args, int);
        }
        while (n_values-- > 0)
            SPA_POD_BUILDER_COLLECT(builder, *format, args);

        if (choice)
            spa_pod_builder_pop(builder, &f);
    } while (true);

      exit:
    return res;
}

SPA_API_POD_BUILDER int spa_pod_builder_add(struct spa_pod_builder *builder, ...)
{
    int res;
    va_list args;

    va_start(args, builder);
    res = spa_pod_builder_addv(builder, args);
    va_end(args);

    return res;
}

#define spa_pod_builder_add_object(b,type,id,...)                \
({                                        \
    struct spa_pod_builder *_b = (b);                    \
    struct spa_pod_frame _f;                        \
    spa_pod_builder_push_object(_b, &_f, type, id);                \
    spa_pod_builder_add(_b, ##__VA_ARGS__, 0);                \
    spa_pod_builder_pop(_b, &_f);                        \
})

#define spa_pod_builder_add_struct(b,...)                    \
({                                        \
    struct spa_pod_builder *_b = (b);                    \
    struct spa_pod_frame _f;                        \
    spa_pod_builder_push_struct(_b, &_f);                    \
    spa_pod_builder_add(_b, ##__VA_ARGS__, NULL);                \
    spa_pod_builder_pop(_b, &_f);                        \
})

#define spa_pod_builder_add_sequence(b,unit,...)                \
({                                        \
    struct spa_pod_builder *_b = (b);                    \
    struct spa_pod_frame _f;                        \
    spa_pod_builder_push_sequence(_b, &_f, unit);                \
    spa_pod_builder_add(_b, ##__VA_ARGS__, 0, 0);                \
    spa_pod_builder_pop(_b, &_f);                        \
})

/** Copy a pod structure */
SPA_API_POD_BUILDER struct spa_pod *
spa_pod_copy(const struct spa_pod *pod)
{
    size_t size;
    struct spa_pod *c;

    size = SPA_POD_SIZE(pod);
    if ((c = (struct spa_pod *) malloc(size)) == NULL)
        return NULL;
    return (struct spa_pod *) memcpy(c, pod, size);
}

/**
 * \}
 */

#ifdef __cplusplus
}  /* extern "C" */
#endif

#endif /* SPA_POD_BUILDER_H */