libwebsockets/lib/misc/jrpc/private-lib-misc-jrpc.h
2021-10-11 09:10:15 +01:00

89 lines
3.3 KiB
C

/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010 - 2020 Andy Green <andy@warmcat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* This written from scratch, but props to falk-werner for his earlier
* work on top of lws for JRPC.
*
* https://github.com/falk-werner/jrpc
*
* https://www.jsonrpc.org/specification
*
* LWS JRPC takes the approach to stream-parse the incoming JRPC object in
* place to maximize the flexibility and parameter sizes that can be handled.
* Although "id" is often last, actually it has no users except to append the
* same id to the response.
*
* Therefore we parse the outer JSON and treat params as a wormhole to be
* parsed by a method-bound user callback.
*
* Streamed request processing must buffer its output before sending, since
* it does not know until the end if it must replace the intended response
* with an exception. It may not know that it wants to make an exception
* until it really processes all the params either. Results must be held in
* a side buffer until the response is able to complete or has errored.
*
* Types for id, method and params are ill-defined. They're all treated as
* strings internally, so a "method": 1 is handled as the string "1". id
* may be NULL, if so it's explicitly returned in the response with "id":null
* Whether id came in as a non-quoted number is remembered and is reproduced
* when giving the id.
*/
/*
* Opaque object representing a request both at the sender and receiver
*/
typedef struct lws_jrpc_obj {
lws_dll2_t list;
struct lejp_ctx lejp_ctx;
void *opaque;
const lws_jrpc_method_t *pmethod; /* only look up once if multi part */
char id[16]; /* includes quotes if was string */
char method[48];
/*
* Eg Sony API "getCurrentExternalTerminalsStatus" (30 chars)
* https://developer.sony.com/develop/audio-control-api/api-references/api-overview-2
*/
char version[4]; /* Eg for Sony, "2.0" */
int parse_result;
uint8_t count_batch_objects;
uint8_t seen_id :1;
uint8_t inside_params :1;
uint8_t has_jrpc_member :1;
uint8_t response :1;
} lws_jrpc_obj_t;
typedef struct lws_jrpc {
lws_dll2_owner_t req_owner;
const lws_jrpc_method_t *methods;
void *opaque;
} lws_jrpc_t;