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// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <stdlib.h>
#include <limits>
#include "base/logging.h"
#include "mojo/edk/system/ports/event.h"
namespace mojo {
namespace edk {
namespace ports {
// static
bool Message::Parse(const void* bytes,
size_t num_bytes,
size_t* num_header_bytes,
size_t* num_payload_bytes,
size_t* num_ports_bytes) {
if (num_bytes < sizeof(EventHeader))
return false;
const EventHeader* header = static_cast<const EventHeader*>(bytes);
switch (header->type) {
case EventType::kUser:
// See below.
break;
case EventType::kPortAccepted:
*num_header_bytes = sizeof(EventHeader);
break;
case EventType::kObserveProxy:
*num_header_bytes = sizeof(EventHeader) + sizeof(ObserveProxyEventData);
break;
case EventType::kObserveProxyAck:
*num_header_bytes =
sizeof(EventHeader) + sizeof(ObserveProxyAckEventData);
break;
case EventType::kObserveClosure:
*num_header_bytes = sizeof(EventHeader) + sizeof(ObserveClosureEventData);
break;
case EventType::kMergePort:
*num_header_bytes = sizeof(EventHeader) + sizeof(MergePortEventData);
break;
default:
return false;
}
if (header->type == EventType::kUser) {
if (num_bytes < sizeof(EventHeader) + sizeof(UserEventData))
return false;
const UserEventData* event_data =
reinterpret_cast<const UserEventData*>(
reinterpret_cast<const char*>(header + 1));
if (event_data->num_ports > std::numeric_limits<uint16_t>::max())
return false;
*num_header_bytes = sizeof(EventHeader) +
sizeof(UserEventData) +
event_data->num_ports * sizeof(PortDescriptor);
*num_ports_bytes = event_data->num_ports * sizeof(PortName);
if (num_bytes < *num_header_bytes + *num_ports_bytes)
return false;
*num_payload_bytes = num_bytes - *num_header_bytes - *num_ports_bytes;
} else {
if (*num_header_bytes != num_bytes)
return false;
*num_payload_bytes = 0;
*num_ports_bytes = 0;
}
return true;
}
Message::Message(size_t num_payload_bytes, size_t num_ports)
: Message(sizeof(EventHeader) + sizeof(UserEventData) +
num_ports * sizeof(PortDescriptor),
num_payload_bytes, num_ports * sizeof(PortName)) {
num_ports_ = num_ports;
}
Message::Message(size_t num_header_bytes,
size_t num_payload_bytes,
size_t num_ports_bytes)
: start_(nullptr),
num_header_bytes_(num_header_bytes),
num_ports_bytes_(num_ports_bytes),
num_payload_bytes_(num_payload_bytes) {
}
void Message::InitializeUserMessageHeader(void* start) {
start_ = static_cast<char*>(start);
memset(start_, 0, num_header_bytes_);
GetMutableEventHeader(this)->type = EventType::kUser;
GetMutableEventData<UserEventData>(this)->num_ports =
static_cast<uint32_t>(num_ports_);
}
} // namespace ports
} // namespace edk
} // namespace mojo
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