/********************
* get_field_names
********************/
static int
get_field_names(context_t *ctx, term_t pl_fields)
{
#define MAX_LENGTH 64 /* max length of a field name */
term_t pl_list, pl_head;
int i, n, left, size;
size_t dummy;
char *p, *field;
if ((n = list_length(pl_fields)) < 0)
return EINVAL;
size = n * sizeof(ctx->fields[0]) + n * MAX_LENGTH;
if ((ctx->fields = malloc(size)) == NULL)
return ENOMEM;
memset(ctx->fields, 0, size);
ctx->nfield = n;
p = ((char *)ctx->fields) + n * sizeof(ctx->fields[0]);
left = size - n * sizeof(ctx->fields[0]);
pl_list = PL_copy_term_ref(pl_fields); /* XXX is this really needed? */
pl_head = PL_new_term_ref();
for (i = 0; i < n && PL_get_list(pl_list, pl_head, pl_list); i++) {
switch (PL_term_type(pl_head)) {
case PL_ATOM:
if (!PL_get_atom_chars(pl_head, &field))
goto fail;
break;
case PL_STRING:
if (!PL_get_string_chars(pl_head, &field, &dummy))
goto fail;
break;
default:
goto fail;
}
ctx->fields[i] = p;
size = snprintf(p, left, "%s", field);
if (size + 1 > left)
goto fail;
p += size + 1;
left -= size + 1;
}
return 0;
fail:
if (ctx->fields != NULL) {
free(ctx->fields);
ctx->fields = NULL;
}
return EINVAL;
}
static foreign_t
pl_sha_hash_ctx(term_t old_ctx, term_t from, term_t new_ctx, term_t hash)
{ char *data;
size_t datalen;
struct context *cp;
size_t clen;
unsigned char hval[SHA2_MAX_DIGEST_SIZE];
if ( !PL_get_nchars(from, &datalen, &data,
CVT_ATOM|CVT_STRING|CVT_LIST|CVT_EXCEPTION) )
return FALSE;
if ( !PL_get_string_chars(old_ctx, (char **)&cp, &clen) )
return FALSE;
if ( clen != sizeof (*cp)
|| cp->magic != CONTEXT_MAGIC ) {
return pl_error(NULL, 0, "Invalid OldContext passed",
ERR_DOMAIN, old_ctx, "algorithm");
}
if ( cp->opts.algorithm == ALGORITHM_SHA1 )
{ sha1_ctx *c1p = &(cp->context.sha1);
sha1_hash((unsigned char*)data, (unsigned long)datalen, c1p);
if ( !PL_unify_string_nchars(new_ctx, sizeof(*cp), (char*)cp) )
return FALSE;
sha1_end((unsigned char *)hval, c1p);
} else
{ sha2_ctx *c1p = &(cp->context.sha2);
sha2_hash((unsigned char*)data, (unsigned long)datalen, c1p);
if ( !PL_unify_string_nchars(new_ctx, sizeof(*cp), (char*)cp) )
return FALSE;
sha2_end((unsigned char *)hval, c1p);
}
/* . */
return PL_unify_list_ncodes(hash, cp->opts.digest_size, (char*)hval);
}
