eccodes/src/grib_accessor_class_raw.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"
/*
   This is used by make_class.pl

   START_CLASS_DEF
   CLASS      = accessor
   SUPER      = grib_accessor_class_gen
   IMPLEMENTS = get_native_type;init;update_size; pack_bytes
   IMPLEMENTS = compare;unpack_bytes;byte_count;value_count
   MEMBERS    = const char* totalLength
   MEMBERS    = const char* sectionLength
   MEMBERS    = long relativeOffset
   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 get_native_type(grib_accessor*);
static int pack_bytes(grib_accessor*, const unsigned char*, size_t* len);
static int unpack_bytes(grib_accessor*, unsigned char*, size_t* len);
static long byte_count(grib_accessor*);
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 compare(grib_accessor*, grib_accessor*);

typedef struct grib_accessor_raw
{
    grib_accessor att;
    /* Members defined in gen */
    /* Members defined in raw */
    const char* totalLength;
    const char* sectionLength;
    long relativeOffset;
} grib_accessor_raw;

extern grib_accessor_class* grib_accessor_class_gen;

static grib_accessor_class _grib_accessor_class_raw = {
    &grib_accessor_class_gen,                      /* super */
    "raw",                      /* name */
    sizeof(grib_accessor_raw),  /* 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 */
    &byte_count,                 /* get number of bytes */
    0,                /* get offset to bytes */
    &get_native_type,            /* get native type */
    0,                /* get sub_section */
    0,               /* pack_missing */
    0,                 /* is_missing */
    0,                  /* pack_long */
    0,                /* unpack_long */
    0,                /* pack_double */
    0,                 /* pack_float */
    0,              /* unpack_double */
    0,               /* unpack_float */
    0,                /* pack_string */
    0,              /* unpack_string */
    0,          /* pack_string_array */
    0,        /* unpack_string_array */
    &pack_bytes,                 /* pack_bytes */
    &unpack_bytes,               /* unpack_bytes */
    0,            /* pack_expression */
    0,              /* notify_change */
    &update_size,                /* update_size */
    0,             /* preferred_size */
    0,                     /* resize */
    0,      /* nearest_smaller_value */
    0,                       /* next accessor */
    &compare,                    /* 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_raw = &_grib_accessor_class_raw;

/* END_CLASS_IMP */

static void init(grib_accessor* a, const long len, grib_arguments* arg)
{
    int n   = 0;
    int err = 0;
    long sectionLength;
    grib_accessor_raw* self = (grib_accessor_raw*)a;
    grib_expression* e;
    grib_handle* hand = grib_handle_of_accessor(a);

    a->length           = 0;
    self->totalLength   = grib_arguments_get_name(hand, arg, n++);
    self->sectionLength = grib_arguments_get_name(hand, arg, n++);

    e   = grib_arguments_get_expression(hand, arg, n++);
    err = grib_expression_evaluate_long(hand, e, &(self->relativeOffset));
    if (err)
        grib_context_log(hand->context, GRIB_LOG_ERROR, "Unable to evaluate relativeOffset");

    grib_get_long(hand, self->sectionLength, &sectionLength);

    a->length = sectionLength - self->relativeOffset;
    if (a->length < 0)
        a->length = 0;

    /* Assert(a->length>=0); */
}

static int get_native_type(grib_accessor* a)
{
    return GRIB_TYPE_BYTES;
}


static int compare(grib_accessor* a, grib_accessor* b)
{
    int retval = GRIB_SUCCESS;

    size_t alen = (size_t)grib_byte_count(a);
    size_t blen = (size_t)grib_byte_count(b);

    if (alen != blen)
        return GRIB_COUNT_MISMATCH;

    return retval;
}

static long byte_count(grib_accessor* a)
{
    return a->length;
}

static int value_count(grib_accessor* a, long* len)
{
    *len = a->length;
    return 0;
}

static int unpack_bytes(grib_accessor* a, unsigned char* buffer, size_t* len)
{
    if (*len < a->length) {
        *len = a->length;
        return GRIB_ARRAY_TOO_SMALL;
    }
    *len = a->length;

    memcpy(buffer, grib_handle_of_accessor(a)->buffer->data + a->offset, *len);

    return GRIB_SUCCESS;
}

static void update_size(grib_accessor* a, size_t s)
{
    grib_context_log(a->context, GRIB_LOG_DEBUG, "updating size of %s old %ld new %ld", a->name, a->length, s);
    a->length = s;
    Assert(a->length >= 0);
}

void accessor_raw_set_length(grib_accessor* a, size_t len)
{
    a->length = len;
}

long accessor_raw_get_offset(grib_accessor* a)
{
    return a->offset;
}

static int pack_bytes(grib_accessor* a, const unsigned char* val, size_t* len)
{
    size_t length = *len;
    long totalLength;
    long sectionLength;
    grib_handle* h          = grib_handle_of_accessor(a);
    grib_accessor_raw* self = (grib_accessor_raw*)a;
    long dlen               = length - a->length;

    grib_get_long(h, self->totalLength, &totalLength);
    totalLength += dlen;
    grib_get_long(h, self->sectionLength, &sectionLength);
    sectionLength += dlen;

    grib_buffer_replace(a, val, length, 1, 1);

    grib_set_long(h, self->totalLength, totalLength);
    grib_set_long(h, self->sectionLength, sectionLength);
    a->length = length;

    return GRIB_SUCCESS;
}