eccodes/src/grib_accessor_class_ieeefloat.cc

/*
 * (C) Copyright 2005- ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 *
 * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
 * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
 */

#include "grib_api_internal.h"
#include <type_traits>
/*
   This is used by make_class.pl

   START_CLASS_DEF
   CLASS      = accessor
   SUPER      = grib_accessor_class_double
   IMPLEMENTS = unpack_double;pack_double
   IMPLEMENTS = unpack_float
   IMPLEMENTS = init
   IMPLEMENTS = value_count
   MEMBERS    = grib_arguments* arg
   IMPLEMENTS = update_size
   IMPLEMENTS = nearest_smaller_value
   END_CLASS_DEF

 */

/* START_CLASS_IMP */

/*

Don't edit anything between START_CLASS_IMP and END_CLASS_IMP
Instead edit values between START_CLASS_DEF and END_CLASS_DEF
or edit "accessor.class" and rerun ./make_class.pl

*/

static int pack_double(grib_accessor*, const double* val, size_t* len);
static int unpack_double(grib_accessor*, double* val, size_t* len);
static int unpack_float(grib_accessor*, float* val, size_t* len);
static int value_count(grib_accessor*, long*);
static void init(grib_accessor*, const long, grib_arguments*);
static void update_size(grib_accessor*, size_t);
static int nearest_smaller_value (grib_accessor*, double, double*);

typedef struct grib_accessor_ieeefloat
{
    grib_accessor att;
    /* Members defined in gen */
    /* Members defined in double */
    /* Members defined in ieeefloat */
    grib_arguments* arg;
} grib_accessor_ieeefloat;

extern grib_accessor_class* grib_accessor_class_double;

static grib_accessor_class _grib_accessor_class_ieeefloat = {
    &grib_accessor_class_double,                      /* super */
    "ieeefloat",                      /* name */
    sizeof(grib_accessor_ieeefloat),  /* size */
    0,                           /* inited */
    0,                           /* init_class */
    &init,                       /* init */
    0,                  /* post_init */
    0,                    /* destroy */
    0,                       /* dump */
    0,                /* next_offset */
    0,              /* get length of string */
    &value_count,                /* get number of values */
    0,                 /* get number of bytes */
    0,                /* get offset to bytes */
    0,            /* get native type */
    0,                /* get sub_section */
    0,               /* pack_missing */
    0,                 /* is_missing */
    0,                  /* pack_long */
    0,                /* unpack_long */
    &pack_double,                /* pack_double */
    0,                 /* pack_float */
    &unpack_double,              /* unpack_double */
    &unpack_float,               /* unpack_float */
    0,                /* pack_string */
    0,              /* unpack_string */
    0,          /* pack_string_array */
    0,        /* unpack_string_array */
    0,                 /* pack_bytes */
    0,               /* unpack_bytes */
    0,            /* pack_expression */
    0,              /* notify_change */
    &update_size,                /* update_size */
    0,             /* preferred_size */
    0,                     /* resize */
    &nearest_smaller_value,      /* nearest_smaller_value */
    0,                       /* next accessor */
    0,                    /* compare vs. another accessor */
    0,      /* unpack only ith value (double) */
    0,       /* unpack only ith value (float) */
    0,  /* unpack a given set of elements (double) */
    0,   /* unpack a given set of elements (float) */
    0,     /* unpack a subarray */
    0,                      /* clear */
    0,                 /* clone accessor */
};


grib_accessor_class* grib_accessor_class_ieeefloat = &_grib_accessor_class_ieeefloat;

/* END_CLASS_IMP */

static void init(grib_accessor* a, const long len, grib_arguments* arg)
{
    grib_accessor_ieeefloat* self = (grib_accessor_ieeefloat*)a;
    long count                    = 0;
    self->arg                     = arg;
    grib_value_count(a, &count);
    a->length = 4 * count;
    Assert(a->length >= 0);
}

static int value_count(grib_accessor* a, long* len)
{
    grib_accessor_ieeefloat* self = (grib_accessor_ieeefloat*)a;
    *len = 0;

    if (!self->arg) {
        *len = 1;
        return 0;
    }
    return grib_get_long_internal(grib_handle_of_accessor(a), grib_arguments_get_name(a->parent->h, self->arg, 0), len);
}

static int pack_double(grib_accessor* a, const double* val, size_t* len)
{
    grib_accessor_ieeefloat* self = (grib_accessor_ieeefloat*)a;
    int ret                       = 0;
    unsigned long i               = 0;
    unsigned long rlen            = (unsigned long)*len;
    size_t buflen                 = 0;
    unsigned char* buf            = NULL;
    long off                      = 0;

    if (*len < 1) {
        grib_context_log(a->context, GRIB_LOG_ERROR, "Wrong size for %s, it packs at least 1 value", a->name);
        *len = 0;
        return GRIB_ARRAY_TOO_SMALL;
    }

    if (rlen == 1) {
        off = a->offset * 8;
        ret = grib_encode_unsigned_long(grib_handle_of_accessor(a)->buffer->data, grib_ieee_to_long(val[0]), &off, 32);
        if (*len > 1)
            grib_context_log(a->context, GRIB_LOG_WARNING, "ieeefloat: Trying to pack %zu values in a scalar %s, packing first value",
                            *len, a->name);
        if (ret == GRIB_SUCCESS)
            len[0] = 1;
        return ret;
    }

    buflen = rlen * 4;

    buf = (unsigned char*)grib_context_malloc(a->context, buflen);

    for (i = 0; i < rlen; i++) {
        grib_encode_unsigned_longb(buf, grib_ieee_to_long(val[i]), &off, 32);
    }
    ret = grib_set_long_internal(grib_handle_of_accessor(a), grib_arguments_get_name(a->parent->h, self->arg, 0), rlen);

    if (ret == GRIB_SUCCESS)
        grib_buffer_replace(a, buf, buflen, 1, 1);
    else
        *len = 0;

    grib_context_free(a->context, buf);

    return ret;
}

template <typename T>
static int unpack(grib_accessor* a, T* val, size_t* len)
{
    static_assert(std::is_floating_point<T>::value, "Requires floating point numbers");
    long rlen = 0;
    int err   = 0;
    long i    = 0;
    long bitp = a->offset * 8;
    grib_handle* hand  = grib_handle_of_accessor(a);

    err = grib_value_count(a, &rlen);
    if (err)
        return err;

    if (*len < (size_t)rlen) {
        grib_context_log(a->context, GRIB_LOG_ERROR, "Wrong size (%zu) for %s, it contains %ld values", *len, a->name, rlen);
        *len = 0;
        return GRIB_ARRAY_TOO_SMALL;
    }

    for (i = 0; i < rlen; i++)
        val[i] = (T)grib_long_to_ieee(grib_decode_unsigned_long(hand->buffer->data, &bitp, 32));

    *len = rlen;
    return GRIB_SUCCESS;
}

static int unpack_double(grib_accessor* a, double* val, size_t* len)
{
    return unpack<double>(a, val, len);
}

static int unpack_float(grib_accessor* a, float* val, size_t* len)
{
    return unpack<float>(a, val, len);
}

static void update_size(grib_accessor* a, size_t s)
{
    a->length = (long)s;
    Assert(a->length >= 0);
}

static int nearest_smaller_value(grib_accessor* a, double val, double* nearest)
{
    return grib_nearest_smaller_ieee_float(val, nearest);
}