/* * %CopyrightBegin% * * Copyright Ericsson AB 1998-2016. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * %CopyrightEnd% */ #ifndef _EICODE_H #define _EICODE_H /* * The following functions are used to encode from c native types directly into * Erlang external format. To use them, you need * * - a destination buffer * - an index counter * - some data * - an idea of how you want to represent the data as an Erlang term. * * You can encode exactly one (1) term into the buffer if you are * going to transmit it to Erlang. Do the following: * * 1. Set your index to 0 * 2. Encode the version into the buffer: ei_encode_version(buf,&index); * The function has now advanced index so the next item can be encoded. * 3. Encode your term: * * Encoding non-compound types (i.e. not lists or tuples) is * straightforward. Just do it! * * Encoding tuples is done by first encoding the tuple header (it * contains the arity) and then encoding the tuple elements in * sequence. * * Encoding lists is done by first encoding the list header (it * contains the arity) and then encoding the list elements in * sequence, and finally encoding an empty list. * * After all this, the index counter will tell you how much buffer you * used. If you really need to know in advance how big the buffer * should be, go through the same steps but with a NULL buffer. No * attempt will be made to modify the buffer, but index will be * updated as though you really did encode something. */ /* encode the given object into buf[index] as 'type'. 0 is * returned and index is updated to the position for the next item. if * buf == NULL, no data is actually copied, but index is updated to * indicate the number of bytes that would have been necessary. */ /* FIXME where do we put these..... */ erlang_big *ei_alloc_big(int arity); void ei_free_big(erlang_big *b); #endif /* _EICODE_H */