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// Copyright 2013 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.
#ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDINGS_SERIALIZATION_H_
#define MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDINGS_SERIALIZATION_H_
#include <vector>
#include "mojo/public/cpp/system/core.h"
namespace mojo {
namespace internal {
class BoundsChecker;
// Please note that this is a different value than |mojo::kInvalidHandleValue|,
// which is the "decoded" invalid handle.
const MojoHandle kEncodedInvalidHandleValue = static_cast<MojoHandle>(-1);
size_t Align(size_t size);
char* AlignPointer(char* ptr);
bool IsAligned(const void* ptr);
// Pointers are encoded as relative offsets. The offsets are relative to the
// address of where the offset value is stored, such that the pointer may be
// recovered with the expression:
//
// ptr = reinterpret_cast<char*>(offset) + *offset
//
// A null pointer is encoded as an offset value of 0.
//
void EncodePointer(const void* ptr, uint64_t* offset);
// Note: This function doesn't validate the encoded pointer value.
const void* DecodePointerRaw(const uint64_t* offset);
// Note: This function doesn't validate the encoded pointer value.
template <typename T>
inline void DecodePointer(const uint64_t* offset, T** ptr) {
*ptr = reinterpret_cast<T*>(const_cast<void*>(DecodePointerRaw(offset)));
}
// Checks whether decoding the pointer will overflow and produce a pointer
// smaller than |offset|.
bool ValidateEncodedPointer(const uint64_t* offset);
// Handles are encoded as indices into a vector of handles. These functions
// manipulate the value of |handle|, mapping it to and from an index.
void EncodeHandle(Handle* handle, std::vector<Handle>* handles);
// Note: This function doesn't validate the encoded handle value.
void DecodeHandle(Handle* handle, std::vector<Handle>* handles);
// The following 2 functions are used to encode/decode all objects (structs and
// arrays) in a consistent manner.
template <typename T>
inline void Encode(T* obj, std::vector<Handle>* handles) {
if (obj->ptr)
obj->ptr->EncodePointersAndHandles(handles);
EncodePointer(obj->ptr, &obj->offset);
}
// Note: This function doesn't validate the encoded pointer and handle values.
template <typename T>
inline void Decode(T* obj, std::vector<Handle>* handles) {
DecodePointer(&obj->offset, &obj->ptr);
if (obj->ptr)
obj->ptr->DecodePointersAndHandles(handles);
}
// If returns true, this function also claims the memory range of the size
// specified in the struct header, starting from |data|.
// Note: |min_num_bytes| must be no less than sizeof(StructHeader).
bool ValidateStructHeader(const void* data,
uint32_t min_num_bytes,
uint32_t min_num_fields,
BoundsChecker* bounds_checker);
} // namespace internal
} // namespace mojo
#endif // MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDINGS_SERIALIZATION_H_
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