aper_encoder.c

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#include <etsi_its_cpm_ts_coding/asn_application.h>
#include <etsi_its_cpm_ts_coding/asn_internal.h>
#include <etsi_its_cpm_ts_coding/aper_encoder.h>
 
/*
 * Argument type and callback necessary for aper_encode_to_buffer().
 */
typedef struct enc_to_buf_arg {
        void *buffer;
        size_t left;
} enc_to_buf_arg;
static int encode_to_buffer_cb(const void *buffer, size_t size, void *key) {
        enc_to_buf_arg *arg = (enc_to_buf_arg *)key;
 
        if(arg->left < size)
                return -1;      /* Data exceeds the available buffer size */
 
        memcpy(arg->buffer, buffer, size);
        arg->buffer = ((char *)arg->buffer) + size;
        arg->left -= size;
 
        return 0;
}
 
asn_enc_rval_t
aper_encode_to_buffer(const asn_TYPE_descriptor_t *td,
                      const asn_per_constraints_t *constraints,
                      const void *sptr, void *buffer, size_t buffer_size) {
    enc_to_buf_arg key;
 
    key.buffer = buffer;
    key.left = buffer_size;
 
    if(td) ASN_DEBUG("Encoding \"%s\" using ALIGNED PER", td->name);
 
    return aper_encode(td, constraints, sptr, encode_to_buffer_cb, &key);
}
 
ssize_t
aper_encode_to_new_buffer(const asn_TYPE_descriptor_t *td,
                          const asn_per_constraints_t *constraints,
                          const void *sptr, void **buffer_r) {
    asn_enc_rval_t er = {0,0,0};
        enc_dyn_arg key;
 
        memset(&key, 0, sizeof(key));
 
        er = aper_encode(td, constraints, sptr, encode_dyn_cb, &key);
        switch(er.encoded) {
        case -1:
                FREEMEM(key.buffer);
                return -1;
        case 0:
                FREEMEM(key.buffer);
                key.buffer = MALLOC(1);
                if(key.buffer) {
                        *(char *)key.buffer = '\0';
                        *buffer_r = key.buffer;
                        return 1;
                } else {
                        return -1;
                }
        default:
                *buffer_r = key.buffer;
                ASN_DEBUG("Complete encoded in %ld bits", (long)er.encoded);
                return ((er.encoded + 7) >> 3);
        }
}
 
/*
 * Internally useful functions.
 */
 
/* Flush partially filled buffer */
static int
_aper_encode_flush_outp(asn_per_outp_t *po) {
        uint8_t *buf;
 
        if(po->nboff == 0 && po->buffer == po->tmpspace)
                return 0;
 
        buf = po->buffer + (po->nboff >> 3);
        /* Make sure we account for the last, partially filled */
        if(po->nboff & 0x07) {
                buf[0] &= 0xff << (8 - (po->nboff & 0x07));
                buf++;
        }
 
        if (po->output) {
                return po->output(po->tmpspace, buf - po->tmpspace, po->op_key);
        }
        return 0;
}
 
asn_enc_rval_t
aper_encode(const asn_TYPE_descriptor_t *td,
        const asn_per_constraints_t *constraints,
        const void *sptr, asn_app_consume_bytes_f *cb, void *app_key) {
        asn_per_outp_t po;
        asn_enc_rval_t er = {0,0,0};
 
        /*
         * Invoke type-specific encoder.
         */
        if(!td || !td->op->aper_encoder)
                ASN__ENCODE_FAILED;      /* PER is not compiled in */
 
        po.buffer = po.tmpspace;
        po.nboff = 0;
        po.nbits = 8 * sizeof(po.tmpspace);
        po.output = cb ? cb : ignore_output;
        po.op_key = app_key;
        po.flushed_bytes = 0;
 
        er = td->op->aper_encoder(td, constraints, sptr, &po);
        if(er.encoded != -1) {
                size_t bits_to_flush;
 
                bits_to_flush = ((po.buffer - po.tmpspace) << 3) + po.nboff;
 
                /* Set number of bits encoded to a firm value */
                er.encoded = (po.flushed_bytes << 3) + bits_to_flush;
 
                if(_aper_encode_flush_outp(&po))
                        ASN__ENCODE_FAILED;
        }
 
        return er;
}