eccodes/src/grib_accessor_class_md5.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 "md5.h"
/*
   This is used by make_class.pl

   START_CLASS_DEF
   CLASS      = accessor
   SUPER      = grib_accessor_class_gen
   IMPLEMENTS = get_native_type;init
   IMPLEMENTS = compare;unpack_string;value_count;destroy
   MEMBERS = const char* offset
   MEMBERS = grib_expression* length
   MEMBERS = grib_string_list* blocklist
   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 unpack_string(grib_accessor*, char*, size_t* len);
static int value_count(grib_accessor*, long*);
static void destroy(grib_context*, grib_accessor*);
static void init(grib_accessor*, const long, grib_arguments*);
static int compare(grib_accessor*, grib_accessor*);

typedef struct grib_accessor_md5
{
    grib_accessor att;
    /* Members defined in gen */
    /* Members defined in md5 */
    const char* offset;
    grib_expression* length;
    grib_string_list* blocklist;
} grib_accessor_md5;

extern grib_accessor_class* grib_accessor_class_gen;

static grib_accessor_class _grib_accessor_class_md5 = {
    &grib_accessor_class_gen,                      /* super */
    "md5",                      /* name */
    sizeof(grib_accessor_md5),  /* size */
    0,                           /* inited */
    0,                           /* init_class */
    &init,                       /* init */
    0,                  /* post_init */
    &destroy,                    /* 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 */
    &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 */
    &unpack_string,              /* unpack_string */
    0,          /* pack_string_array */
    0,        /* unpack_string_array */
    0,                 /* pack_bytes */
    0,               /* unpack_bytes */
    0,            /* pack_expression */
    0,              /* notify_change */
    0,                /* 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_md5 = &_grib_accessor_class_md5;

/* END_CLASS_IMP */

static void init(grib_accessor* a, const long len, grib_arguments* arg)
{
    grib_accessor_md5* self   = (grib_accessor_md5*)a;
    char* b                   = 0;
    int n                     = 0;
    grib_string_list* current = 0;
    grib_context* context     = a->context;

    self->offset    = grib_arguments_get_name(grib_handle_of_accessor(a), arg, n++);
    self->length    = grib_arguments_get_expression(grib_handle_of_accessor(a), arg, n++);
    self->blocklist = NULL;
    while ((b = (char*)grib_arguments_get_name(grib_handle_of_accessor(a), arg, n++)) != NULL) {
        if (!self->blocklist) {
            self->blocklist        = (grib_string_list*)grib_context_malloc_clear(context, sizeof(grib_string_list));
            self->blocklist->value = grib_context_strdup(context, b);
            current                = self->blocklist;
        }
        else {
            Assert(current);
            if (current) {
                current->next        = (grib_string_list*)grib_context_malloc_clear(context, sizeof(grib_string_list));
                current->next->value = grib_context_strdup(context, b);
                current              = current->next;
            }
        }
    }
    a->length = 0;
    a->flags |= GRIB_ACCESSOR_FLAG_READ_ONLY;
    a->flags |= GRIB_ACCESSOR_FLAG_EDITION_SPECIFIC;
}

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

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

    size_t alen = 0;
    size_t blen = 0;
    int err     = 0;
    long count  = 0;

    err = grib_value_count(a, &count);
    if (err)
        return err;
    alen = count;

    err = grib_value_count(b, &count);
    if (err)
        return err;
    blen = count;

    if (alen != blen)
        return GRIB_COUNT_MISMATCH;

    return retval;
}

static int unpack_string(grib_accessor* a, char* v, size_t* len)
{
    grib_accessor_md5* self = (grib_accessor_md5*)a;
    unsigned mess_len;
    unsigned char* mess;
    unsigned char* p;
    long offset = 0, length = 0;
    grib_string_list* blocklist = NULL;
    int ret = GRIB_SUCCESS;
    long i = 0;
    struct grib_md5_state md5c;

    if (*len < 32) {
        const char* cclass_name = a->cclass->name;
        grib_context_log(a->context, GRIB_LOG_ERROR,
                         "%s: Buffer too small for %s. It is %d bytes long (len=%zu)",
                         cclass_name, a->name, 32, *len);
        *len = 32;
        return GRIB_BUFFER_TOO_SMALL;
    }

    if ((ret = grib_get_long_internal(grib_handle_of_accessor(a), self->offset, &offset)) != GRIB_SUCCESS)
        return ret;
    if ((ret = grib_expression_evaluate_long(grib_handle_of_accessor(a), self->length, &length)) != GRIB_SUCCESS)
        return ret;
    mess = (unsigned char*)grib_context_malloc(a->context, length);
    memcpy(mess, grib_handle_of_accessor(a)->buffer->data + offset, length);
    mess_len = length;

    blocklist = a->context->blocklist;
    /* passed blocklist overrides context blocklist.
     Consider to modify following line to extend context blocklist.
     */
    if (self->blocklist)
        blocklist = self->blocklist;
    while (blocklist && blocklist->value) {
        const grib_accessor* b = grib_find_accessor(grib_handle_of_accessor(a), blocklist->value);
        if (!b) {
            grib_context_free(a->context, mess);
            return GRIB_NOT_FOUND;
        }

        p = mess + b->offset - offset;
        for (i = 0; i < b->length; i++)
            *(p++) = 0;

        blocklist = blocklist->next;
    }

    grib_md5_init(&md5c);
    grib_md5_add(&md5c, mess, mess_len);
    grib_md5_end(&md5c, v);
    grib_context_free(a->context, mess);
    *len = strlen(v) + 1;

    return ret;
}

static void destroy(grib_context* c, grib_accessor* a)
{
    grib_accessor_md5* self = (grib_accessor_md5*)a;
    if (self->blocklist) {
        grib_string_list* next = self->blocklist;
        grib_string_list* cur  = NULL;
        while (next) {
            cur  = next;
            next = next->next;
            grib_context_free(c, cur->value);
            grib_context_free(c, cur);
        }
    }
}

static int value_count(grib_accessor* a, long* count)
{
    *count = 1; /* ECC-1475 */
    return 0;
}