godot/modules/websocket/lws_helper.h

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/*************************************************************************/
/* lws_helper.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md) */
/* */
/* 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. */
/*************************************************************************/
#ifndef LWS_HELPER_H
#define LWS_HELPER_H
#define LWS_BUF_SIZE 65536
#define LWS_PACKET_SIZE LWS_BUF_SIZE
#include "core/io/stream_peer.h"
#include "core/os/os.h"
#include "core/reference.h"
#include "core/ring_buffer.h"
#include "lws_peer.h"
struct _LWSRef {
bool free_context;
bool is_polling;
bool is_valid;
bool is_destroying;
void *obj;
struct lws_protocols *lws_structs;
char *lws_names;
};
static _LWSRef *_lws_create_ref(void *obj) {
_LWSRef *out = (_LWSRef *)memalloc(sizeof(_LWSRef));
out->is_destroying = false;
out->free_context = false;
out->is_polling = false;
out->obj = obj;
out->is_valid = true;
out->lws_structs = NULL;
out->lws_names = NULL;
return out;
}
static void _lws_free_ref(_LWSRef *ref) {
// Free strings and structs
memfree(ref->lws_structs);
memfree(ref->lws_names);
// Free ref
memfree(ref);
}
static bool _lws_destroy(struct lws_context *context, _LWSRef *ref) {
if (context == NULL || ref->is_destroying)
return false;
if (ref->is_polling) {
ref->free_context = true;
return false;
}
ref->is_destroying = true;
lws_context_destroy(context);
_lws_free_ref(ref);
return true;
}
static bool _lws_poll(struct lws_context *context, _LWSRef *ref) {
ERR_FAIL_COND_V(context == NULL, false);
ERR_FAIL_COND_V(ref == NULL, false);
ref->is_polling = true;
lws_service(context, 0);
ref->is_polling = false;
if (!ref->free_context)
return false; // Nothing to do
bool is_valid = ref->is_valid; // Might have been destroyed by poll
_lws_destroy(context, ref); // Will destroy context and ref
return is_valid; // If the object should NULL its context and ref
}
/*
* Prepare the protocol_structs to be fed to context.
* Also prepare the protocol string used by the client.
*/
static void _lws_make_protocols(void *p_obj, lws_callback_function *p_callback, PoolVector<String> p_names, _LWSRef **r_lws_ref) {
// The input strings might go away after this call, we need to copy them.
// We will clear them when destroying the context.
int i;
int len = p_names.size();
size_t data_size = sizeof(struct LWSPeer::PeerData);
PoolVector<String>::Read pnr = p_names.read();
// This is a reference connecting the object with lws keep track of status, mallocs, etc.
// Must survive as long the context.
// Must be freed manually when context creation fails.
_LWSRef *ref = _lws_create_ref(p_obj);
// LWS protocol structs.
ref->lws_structs = (struct lws_protocols *)memalloc(sizeof(struct lws_protocols) * (len + 2));
memset(ref->lws_structs, 0, sizeof(struct lws_protocols) * (len + 2));
CharString strings = p_names.join(",").ascii();
int str_len = strings.length();
// Joined string of protocols, double the size: comma separated first, NULL separated last
ref->lws_names = (char *)memalloc((str_len + 1) * 2); // Plus the terminator
char *names_ptr = ref->lws_names;
struct lws_protocols *structs_ptr = ref->lws_structs;
// Comma separated protocols string to be used in client Sec-WebSocket-Protocol header
if (str_len > 0)
copymem(names_ptr, strings.get_data(), str_len);
names_ptr[str_len] = '\0'; // NULL terminator
// NULL terminated protocol strings to be used in protocol structs
if (str_len > 0)
copymem(&names_ptr[str_len + 1], strings.get_data(), str_len);
names_ptr[(str_len * 2) + 1] = '\0'; // NULL terminator
int pos = str_len + 1;
// The first protocol is the default for any http request (before upgrade).
// It is also used as the websocket protocol when no subprotocol is specified.
structs_ptr[0].name = "default";
structs_ptr[0].callback = p_callback;
structs_ptr[0].per_session_data_size = data_size;
structs_ptr[0].rx_buffer_size = LWS_BUF_SIZE;
structs_ptr[0].tx_packet_size = LWS_PACKET_SIZE;
// Add user defined protocols
for (i = 0; i < len; i++) {
structs_ptr[i + 1].name = (const char *)&names_ptr[pos];
structs_ptr[i + 1].callback = p_callback;
structs_ptr[i + 1].per_session_data_size = data_size;
structs_ptr[i + 1].rx_buffer_size = LWS_BUF_SIZE;
structs_ptr[i + 1].tx_packet_size = LWS_PACKET_SIZE;
pos += pnr[i].ascii().length() + 1;
names_ptr[pos - 1] = '\0';
}
// Add protocols terminator
structs_ptr[len + 1].name = NULL;
structs_ptr[len + 1].callback = NULL;
structs_ptr[len + 1].per_session_data_size = 0;
structs_ptr[len + 1].rx_buffer_size = 0;
*r_lws_ref = ref;
}
/* clang-format off */
#define LWS_HELPER(CNAME) \
protected: \
struct _LWSRef *_lws_ref; \
struct lws_context *context; \
\
static int _lws_gd_callback(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len) { \
\
if (wsi == NULL) { \
return 0; \
} \
\
struct _LWSRef *ref = (struct _LWSRef *)lws_context_user(lws_get_context(wsi)); \
if (!ref->is_valid) \
return 0; \
CNAME *helper = (CNAME *)ref->obj; \
return helper->_handle_cb(wsi, reason, user, in, len); \
} \
\
void invalidate_lws_ref() { \
if (_lws_ref != NULL) \
_lws_ref->is_valid = false; \
} \
\
void destroy_context() { \
if (_lws_destroy(context, _lws_ref)) { \
context = NULL; \
_lws_ref = NULL; \
} \
} \
\
public: \
virtual int _handle_cb(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len); \
\
void _lws_poll() { \
ERR_FAIL_COND(context == NULL); \
\
if (::_lws_poll(context, _lws_ref)) { \
context = NULL; \
_lws_ref = NULL; \
} \
} \
\
protected:
/* clang-format on */
#endif // LWS_HELPER_H