/usr/include/google/protobuf
Edit: /usr/include/google/protobuf/metadata_lite.h (8260B)
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef GOOGLE_PROTOBUF_METADATA_LITE_H__
#define GOOGLE_PROTOBUF_METADATA_LITE_H__
#include
#include
#include
#include
#include
#ifdef SWIG
#error "You cannot SWIG proto headers"
#endif
namespace google {
namespace protobuf {
namespace internal {
// This is the representation for messages that support arena allocation. It
// uses a tagged pointer to either store the Arena pointer, if there are no
// unknown fields, or a pointer to a block of memory with both the Arena pointer
// and the UnknownFieldSet, if there are unknown fields. This optimization
// allows for "zero-overhead" storage of the Arena pointer, relative to the
// above baseline implementation.
//
// The tagged pointer uses the LSB to disambiguate cases, and uses bit 0 == 0 to
// indicate an arena pointer and bit 0 == 1 to indicate a UFS+Arena-container
// pointer.
class InternalMetadata {
public:
InternalMetadata() : ptr_(nullptr) {}
explicit InternalMetadata(Arena* arena) : ptr_(arena) {}
template
void Delete() {
// Note that Delete<> should be called not more than once.
if (have_unknown_fields() && arena() == NULL) {
delete PtrValue>();
}
}
PROTOBUF_ALWAYS_INLINE Arena* arena() const {
if (PROTOBUF_PREDICT_FALSE(have_unknown_fields())) {
return PtrValue()->arena;
} else {
return PtrValue();
}
}
PROTOBUF_ALWAYS_INLINE bool have_unknown_fields() const {
return PtrTag() == kTagContainer;
}
PROTOBUF_ALWAYS_INLINE void* raw_arena_ptr() const { return ptr_; }
template
PROTOBUF_ALWAYS_INLINE const T& unknown_fields(
const T& (*default_instance)()) const {
if (PROTOBUF_PREDICT_FALSE(have_unknown_fields())) {
return PtrValue>()->unknown_fields;
} else {
return default_instance();
}
}
template
PROTOBUF_ALWAYS_INLINE T* mutable_unknown_fields() {
if (PROTOBUF_PREDICT_TRUE(have_unknown_fields())) {
return &PtrValue>()->unknown_fields;
} else {
return mutable_unknown_fields_slow();
}
}
template
PROTOBUF_ALWAYS_INLINE void Swap(InternalMetadata* other) {
// Semantics here are that we swap only the unknown fields, not the arena
// pointer. We cannot simply swap ptr_ with other->ptr_ because we need to
// maintain our own arena ptr. Also, our ptr_ and other's ptr_ may be in
// different states (direct arena pointer vs. container with UFS) so we
// cannot simply swap ptr_ and then restore the arena pointers. We reuse
// UFS's swap implementation instead.
if (have_unknown_fields() || other->have_unknown_fields()) {
DoSwap(other->mutable_unknown_fields());
}
}
template
PROTOBUF_ALWAYS_INLINE void MergeFrom(const InternalMetadata& other) {
if (other.have_unknown_fields()) {
DoMergeFrom(other.unknown_fields(nullptr));
}
}
template
PROTOBUF_ALWAYS_INLINE void Clear() {
if (have_unknown_fields()) {
DoClear();
}
}
private:
void* ptr_;
// Tagged pointer implementation.
enum {
// ptr_ is an Arena*.
kTagArena = 0,
// ptr_ is a Container*.
kTagContainer = 1,
};
static constexpr intptr_t kPtrTagMask = 1;
static constexpr intptr_t kPtrValueMask = ~kPtrTagMask;
// Accessors for pointer tag and pointer value.
PROTOBUF_ALWAYS_INLINE int PtrTag() const {
return reinterpret_cast(ptr_) & kPtrTagMask;
}
template
U* PtrValue() const {
return reinterpret_cast(reinterpret_cast(ptr_) &
kPtrValueMask);
}
// If ptr_'s tag is kTagContainer, it points to an instance of this struct.
struct ContainerBase {
Arena* arena;
};
template
struct Container : public ContainerBase {
T unknown_fields;
};
template
PROTOBUF_NOINLINE T* mutable_unknown_fields_slow() {
Arena* my_arena = arena();
Container* container = Arena::Create>(my_arena);
// Two-step assignment works around a bug in clang's static analyzer:
// https://bugs.llvm.org/show_bug.cgi?id=34198.
ptr_ = container;
ptr_ = reinterpret_cast(reinterpret_cast(ptr_) |
kTagContainer);
container->arena = my_arena;
return &(container->unknown_fields);
}
// Templated functions.
template
void DoClear() {
mutable_unknown_fields()->Clear();
}
template
void DoMergeFrom(const T& other) {
mutable_unknown_fields()->MergeFrom(other);
}
template
void DoSwap(T* other) {
mutable_unknown_fields()->Swap(other);
}
};
// String Template specializations.
template <>
inline void InternalMetadata::DoClear() {
mutable_unknown_fields()->clear();
}
template <>
inline void InternalMetadata::DoMergeFrom(
const std::string& other) {
mutable_unknown_fields()->append(other);
}
template <>
inline void InternalMetadata::DoSwap(std::string* other) {
mutable_unknown_fields()->swap(*other);
}
// This helper RAII class is needed to efficiently parse unknown fields. We
// should only call mutable_unknown_fields if there are actual unknown fields.
// The obvious thing to just use a stack string and swap it at the end of
// the parse won't work, because the destructor of StringOutputStream needs to
// be called before we can modify the string (it check-fails). Using
// LiteUnknownFieldSetter setter(&_internal_metadata_);
// StringOutputStream stream(setter.buffer());
// guarantees that the string is only swapped after stream is destroyed.
class PROTOBUF_EXPORT LiteUnknownFieldSetter {
public:
explicit LiteUnknownFieldSetter(InternalMetadata* metadata)
: metadata_(metadata) {
if (metadata->have_unknown_fields()) {
buffer_.swap(*metadata->mutable_unknown_fields());
}
}
~LiteUnknownFieldSetter() {
if (!buffer_.empty())
metadata_->mutable_unknown_fields()->swap(buffer_);
}
std::string* buffer() { return &buffer_; }
private:
InternalMetadata* metadata_;
std::string buffer_;
};
} // namespace internal
} // namespace protobuf
} // namespace google
#include
#endif // GOOGLE_PROTOBUF_METADATA_LITE_H__