godot/scene/main/multiplayer_api.cpp
Fabio Alessandrelli 75de626781 [MP] Fix variant serialization after variant size change.
The bit mask used for the type when compressing variants in the
Multiplayer API became too small to represent all variant types.

This commit expand the mask, which means we no longer have an extra bit
in the "meta" byte we use to store encoding information.

The extra bit was only used in case of booleans to store the value and
since booleans do not require extra encoding information we use those 2
bits to store the value instead.
2022-08-24 19:46:55 +02:00

417 lines
14 KiB
C++

/*************************************************************************/
/* multiplayer_api.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 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, */
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/*************************************************************************/
#include "multiplayer_api.h"
#include "core/debugger/engine_debugger.h"
#include "core/io/marshalls.h"
#include <stdint.h>
#ifdef DEBUG_ENABLED
#include "core/os/os.h"
#endif
StringName MultiplayerAPI::default_interface = StringName();
void MultiplayerAPI::set_default_interface(const StringName &p_interface) {
ERR_FAIL_COND_MSG(!ClassDB::is_parent_class(p_interface, MultiplayerAPI::get_class_static()), vformat("Can't make %s the default multiplayer interface since it does not extend MultiplayerAPI.", p_interface));
default_interface = p_interface;
}
StringName MultiplayerAPI::get_default_interface() {
return default_interface;
}
Ref<MultiplayerAPI> MultiplayerAPI::create_default_interface() {
if (default_interface != StringName()) {
return Ref<MultiplayerAPI>(Object::cast_to<MultiplayerAPI>(ClassDB::instantiate(default_interface)));
}
return Ref<MultiplayerAPI>(memnew(MultiplayerAPIExtension));
}
// The variant is compressed and encoded; The first byte contains all the meta
// information and the format is:
// - The first LSB 6 bits are used for the variant type.
// - The next two bits are used to store the encoding mode.
// - Boolean values uses the encoding mode to store the value.
#define VARIANT_META_TYPE_MASK 0x3F
#define VARIANT_META_EMODE_MASK 0xC0
#define VARIANT_META_BOOL_MASK 0x80
#define ENCODE_8 0 << 6
#define ENCODE_16 1 << 6
#define ENCODE_32 2 << 6
#define ENCODE_64 3 << 6
Error MultiplayerAPI::encode_and_compress_variant(const Variant &p_variant, uint8_t *r_buffer, int &r_len, bool p_allow_object_decoding) {
// Unreachable because `VARIANT_MAX` == 38 and `ENCODE_VARIANT_MASK` == 77
CRASH_COND(p_variant.get_type() > VARIANT_META_TYPE_MASK);
uint8_t *buf = r_buffer;
r_len = 0;
uint8_t encode_mode = 0;
switch (p_variant.get_type()) {
case Variant::BOOL: {
if (buf) {
// We don't use encode_mode for booleans, so we can use it to store the value.
buf[0] = (p_variant.operator bool()) ? (1 << 7) : 0;
buf[0] |= p_variant.get_type();
}
r_len += 1;
} break;
case Variant::INT: {
if (buf) {
// Reserve the first byte for the meta.
buf += 1;
}
r_len += 1;
int64_t val = p_variant;
if (val <= (int64_t)INT8_MAX && val >= (int64_t)INT8_MIN) {
// Use 8 bit
encode_mode = ENCODE_8;
if (buf) {
buf[0] = val;
}
r_len += 1;
} else if (val <= (int64_t)INT16_MAX && val >= (int64_t)INT16_MIN) {
// Use 16 bit
encode_mode = ENCODE_16;
if (buf) {
encode_uint16(val, buf);
}
r_len += 2;
} else if (val <= (int64_t)INT32_MAX && val >= (int64_t)INT32_MIN) {
// Use 32 bit
encode_mode = ENCODE_32;
if (buf) {
encode_uint32(val, buf);
}
r_len += 4;
} else {
// Use 64 bit
encode_mode = ENCODE_64;
if (buf) {
encode_uint64(val, buf);
}
r_len += 8;
}
// Store the meta
if (buf) {
buf -= 1;
buf[0] = encode_mode | p_variant.get_type();
}
} break;
default:
// Any other case is not yet compressed.
Error err = encode_variant(p_variant, r_buffer, r_len, p_allow_object_decoding);
if (err != OK) {
return err;
}
if (r_buffer) {
// The first byte is not used by the marshalling, so store the type
// so we know how to decompress and decode this variant.
r_buffer[0] = p_variant.get_type();
}
}
return OK;
}
Error MultiplayerAPI::decode_and_decompress_variant(Variant &r_variant, const uint8_t *p_buffer, int p_len, int *r_len, bool p_allow_object_decoding) {
const uint8_t *buf = p_buffer;
int len = p_len;
ERR_FAIL_COND_V(len < 1, ERR_INVALID_DATA);
uint8_t type = buf[0] & VARIANT_META_TYPE_MASK;
uint8_t encode_mode = buf[0] & VARIANT_META_EMODE_MASK;
ERR_FAIL_COND_V(type >= Variant::VARIANT_MAX, ERR_INVALID_DATA);
switch (type) {
case Variant::BOOL: {
bool val = (buf[0] & VARIANT_META_BOOL_MASK) > 0;
r_variant = val;
if (r_len) {
*r_len = 1;
}
} break;
case Variant::INT: {
buf += 1;
len -= 1;
if (r_len) {
*r_len = 1;
}
if (encode_mode == ENCODE_8) {
// 8 bits.
ERR_FAIL_COND_V(len < 1, ERR_INVALID_DATA);
int8_t val = buf[0];
r_variant = val;
if (r_len) {
(*r_len) += 1;
}
} else if (encode_mode == ENCODE_16) {
// 16 bits.
ERR_FAIL_COND_V(len < 2, ERR_INVALID_DATA);
int16_t val = decode_uint16(buf);
r_variant = val;
if (r_len) {
(*r_len) += 2;
}
} else if (encode_mode == ENCODE_32) {
// 32 bits.
ERR_FAIL_COND_V(len < 4, ERR_INVALID_DATA);
int32_t val = decode_uint32(buf);
r_variant = val;
if (r_len) {
(*r_len) += 4;
}
} else {
// 64 bits.
ERR_FAIL_COND_V(len < 8, ERR_INVALID_DATA);
int64_t val = decode_uint64(buf);
r_variant = val;
if (r_len) {
(*r_len) += 8;
}
}
} break;
default:
Error err = decode_variant(r_variant, p_buffer, p_len, r_len, p_allow_object_decoding);
if (err != OK) {
return err;
}
}
return OK;
}
Error MultiplayerAPI::encode_and_compress_variants(const Variant **p_variants, int p_count, uint8_t *p_buffer, int &r_len, bool *r_raw, bool p_allow_object_decoding) {
r_len = 0;
int size = 0;
if (p_count == 0) {
if (r_raw) {
*r_raw = true;
}
return OK;
}
// Try raw encoding optimization.
if (r_raw && p_count == 1) {
*r_raw = false;
const Variant &v = *(p_variants[0]);
if (v.get_type() == Variant::PACKED_BYTE_ARRAY) {
*r_raw = true;
const PackedByteArray pba = v;
if (p_buffer) {
memcpy(p_buffer, pba.ptr(), pba.size());
}
r_len += pba.size();
} else {
encode_and_compress_variant(v, p_buffer, size, p_allow_object_decoding);
r_len += size;
}
return OK;
}
// Regular encoding.
for (int i = 0; i < p_count; i++) {
const Variant &v = *(p_variants[i]);
encode_and_compress_variant(v, p_buffer ? p_buffer + r_len : nullptr, size, p_allow_object_decoding);
r_len += size;
}
return OK;
}
Error MultiplayerAPI::decode_and_decompress_variants(Vector<Variant> &r_variants, const uint8_t *p_buffer, int p_len, int &r_len, bool p_raw, bool p_allow_object_decoding) {
r_len = 0;
int argc = r_variants.size();
if (argc == 0 && p_raw) {
return OK;
}
ERR_FAIL_COND_V(p_raw && argc != 1, ERR_INVALID_DATA);
if (p_raw) {
r_len = p_len;
PackedByteArray pba;
pba.resize(p_len);
memcpy(pba.ptrw(), p_buffer, p_len);
r_variants.write[0] = pba;
return OK;
}
Vector<Variant> args;
Vector<const Variant *> argp;
args.resize(argc);
for (int i = 0; i < argc; i++) {
ERR_FAIL_COND_V_MSG(r_len >= p_len, ERR_INVALID_DATA, "Invalid packet received. Size too small.");
int vlen;
Error err = MultiplayerAPI::decode_and_decompress_variant(r_variants.write[i], &p_buffer[r_len], p_len - r_len, &vlen, p_allow_object_decoding);
ERR_FAIL_COND_V_MSG(err != OK, err, "Invalid packet received. Unable to decode state variable.");
r_len += vlen;
}
return OK;
}
Error MultiplayerAPI::_rpc_bind(int p_peer, Object *p_object, const StringName &p_method, Array p_args) {
Vector<Variant> args;
Vector<const Variant *> argsp;
args.resize(p_args.size());
argsp.resize(p_args.size());
Variant *ptr = args.ptrw();
const Variant **pptr = argsp.ptrw();
for (int i = 0; i < p_args.size(); i++) {
ptr[i] = p_args[i];
pptr[i] = &ptr[i];
}
return rpcp(p_object, p_peer, p_method, argsp.size() ? argsp.ptrw() : nullptr, argsp.size());
}
void MultiplayerAPI::_bind_methods() {
ClassDB::bind_method(D_METHOD("has_multiplayer_peer"), &MultiplayerAPI::has_multiplayer_peer);
ClassDB::bind_method(D_METHOD("get_multiplayer_peer"), &MultiplayerAPI::get_multiplayer_peer);
ClassDB::bind_method(D_METHOD("set_multiplayer_peer", "peer"), &MultiplayerAPI::set_multiplayer_peer);
ClassDB::bind_method(D_METHOD("get_unique_id"), &MultiplayerAPI::get_unique_id);
ClassDB::bind_method(D_METHOD("is_server"), &MultiplayerAPI::is_server);
ClassDB::bind_method(D_METHOD("get_remote_sender_id"), &MultiplayerAPI::get_remote_sender_id);
ClassDB::bind_method(D_METHOD("poll"), &MultiplayerAPI::poll);
ClassDB::bind_method(D_METHOD("rpc", "peer", "object", "method", "arguments"), &MultiplayerAPI::_rpc_bind, DEFVAL(Array()));
ClassDB::bind_method(D_METHOD("object_configuration_add", "object", "configuration"), &MultiplayerAPI::object_configuration_add);
ClassDB::bind_method(D_METHOD("object_configuration_remove", "object", "configuration"), &MultiplayerAPI::object_configuration_remove);
ClassDB::bind_method(D_METHOD("get_peers"), &MultiplayerAPI::get_peer_ids);
ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "multiplayer_peer", PROPERTY_HINT_RESOURCE_TYPE, "MultiplayerPeer", PROPERTY_USAGE_NONE), "set_multiplayer_peer", "get_multiplayer_peer");
ClassDB::bind_static_method("MultiplayerAPI", D_METHOD("set_default_interface", "interface_name"), &MultiplayerAPI::set_default_interface);
ClassDB::bind_static_method("MultiplayerAPI", D_METHOD("get_default_interface"), &MultiplayerAPI::get_default_interface);
ClassDB::bind_static_method("MultiplayerAPI", D_METHOD("create_default_interface"), &MultiplayerAPI::create_default_interface);
ADD_SIGNAL(MethodInfo("peer_connected", PropertyInfo(Variant::INT, "id")));
ADD_SIGNAL(MethodInfo("peer_disconnected", PropertyInfo(Variant::INT, "id")));
ADD_SIGNAL(MethodInfo("connected_to_server"));
ADD_SIGNAL(MethodInfo("connection_failed"));
ADD_SIGNAL(MethodInfo("server_disconnected"));
BIND_ENUM_CONSTANT(RPC_MODE_DISABLED);
BIND_ENUM_CONSTANT(RPC_MODE_ANY_PEER);
BIND_ENUM_CONSTANT(RPC_MODE_AUTHORITY);
}
/// MultiplayerAPIExtension
Error MultiplayerAPIExtension::poll() {
int err;
if (GDVIRTUAL_CALL(_poll, err)) {
return (Error)err;
}
return OK;
}
void MultiplayerAPIExtension::set_multiplayer_peer(const Ref<MultiplayerPeer> &p_peer) {
GDVIRTUAL_CALL(_set_multiplayer_peer, p_peer);
}
Ref<MultiplayerPeer> MultiplayerAPIExtension::get_multiplayer_peer() {
Ref<MultiplayerPeer> peer;
if (GDVIRTUAL_CALL(_get_multiplayer_peer, peer)) {
return peer;
}
return nullptr;
}
int MultiplayerAPIExtension::get_unique_id() {
int id;
if (GDVIRTUAL_CALL(_get_unique_id, id)) {
return id;
}
return 1;
}
Vector<int> MultiplayerAPIExtension::get_peer_ids() {
Vector<int> ids;
if (GDVIRTUAL_CALL(_get_peer_ids, ids)) {
return ids;
}
return Vector<int>();
}
Error MultiplayerAPIExtension::rpcp(Object *p_obj, int p_peer_id, const StringName &p_method, const Variant **p_arg, int p_argcount) {
if (!GDVIRTUAL_IS_OVERRIDDEN(_rpc)) {
return ERR_UNAVAILABLE;
}
Array args;
for (int i = 0; i < p_argcount; i++) {
args.push_back(*p_arg[i]);
}
int ret;
if (GDVIRTUAL_CALL(_rpc, p_peer_id, p_obj, p_method, args, ret)) {
return (Error)ret;
}
return FAILED;
}
int MultiplayerAPIExtension::get_remote_sender_id() {
int id;
if (GDVIRTUAL_CALL(_get_remote_sender_id, id)) {
return id;
}
return 0;
}
Error MultiplayerAPIExtension::object_configuration_add(Object *p_object, Variant p_config) {
int err;
if (GDVIRTUAL_CALL(_object_configuration_add, p_object, p_config, err)) {
return (Error)err;
}
return ERR_UNAVAILABLE;
}
Error MultiplayerAPIExtension::object_configuration_remove(Object *p_object, Variant p_config) {
int err;
if (GDVIRTUAL_CALL(_object_configuration_remove, p_object, p_config, err)) {
return (Error)err;
}
return ERR_UNAVAILABLE;
}
void MultiplayerAPIExtension::_bind_methods() {
GDVIRTUAL_BIND(_poll);
GDVIRTUAL_BIND(_set_multiplayer_peer, "multiplayer_peer");
GDVIRTUAL_BIND(_get_multiplayer_peer);
GDVIRTUAL_BIND(_get_unique_id);
GDVIRTUAL_BIND(_get_peer_ids);
GDVIRTUAL_BIND(_rpc, "peer", "object", "method", "args");
GDVIRTUAL_BIND(_get_remote_sender_id);
GDVIRTUAL_BIND(_object_configuration_add, "object", "configuration");
GDVIRTUAL_BIND(_object_configuration_remove, "object", "configuration");
}