| // 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_ARENASTRING_H__ |
| #define GOOGLE_PROTOBUF_ARENASTRING_H__ |
| |
| #include <string> |
| |
| #include <google/protobuf/arena.h> |
| #include <google/protobuf/stubs/common.h> |
| #include <google/protobuf/stubs/fastmem.h> |
| #include <google/protobuf/stubs/logging.h> |
| #include <google/protobuf/stubs/port.h> |
| |
| // This is the implementation of arena string fields written for the open-source |
| // release. The ArenaStringPtr struct below is an internal implementation class |
| // and *should not be used* by user code. It is used to collect string |
| // operations together into one place and abstract away the underlying |
| // string-field pointer representation, so that (for example) an alternate |
| // implementation that knew more about ::std::string's internals could integrate more |
| // closely with the arena allocator. |
| |
| namespace google { |
| namespace protobuf { |
| namespace internal { |
| |
| template <typename T> |
| class TaggedPtr { |
| public: |
| void Set(T* p) { ptr_ = reinterpret_cast<uintptr_t>(p); } |
| T* Get() const { return reinterpret_cast<T*>(ptr_); } |
| |
| bool IsNull() { return ptr_ == 0; } |
| |
| private: |
| uintptr_t ptr_; |
| }; |
| |
| struct LIBPROTOBUF_EXPORT ArenaStringPtr { |
| inline void Set(const ::std::string* default_value, |
| const ::std::string& value, ::google::protobuf::Arena* arena) { |
| if (ptr_ == default_value) { |
| CreateInstance(arena, &value); |
| } else { |
| *ptr_ = value; |
| } |
| } |
| |
| inline void SetLite(const ::std::string* default_value, |
| const ::std::string& value, |
| ::google::protobuf::Arena* arena) { |
| Set(default_value, value, arena); |
| } |
| |
| // Basic accessors. |
| inline const ::std::string& Get() const { return *ptr_; } |
| |
| inline ::std::string* Mutable(const ::std::string* default_value, |
| ::google::protobuf::Arena* arena) { |
| if (ptr_ == default_value) { |
| CreateInstance(arena, default_value); |
| } |
| return ptr_; |
| } |
| |
| // Release returns a ::std::string* instance that is heap-allocated and is not |
| // Own()'d by any arena. If the field was not set, it returns NULL. The caller |
| // retains ownership. Clears this field back to NULL state. Used to implement |
| // release_<field>() methods on generated classes. |
| inline ::std::string* Release(const ::std::string* default_value, |
| ::google::protobuf::Arena* arena) { |
| if (ptr_ == default_value) { |
| return NULL; |
| } |
| return ReleaseNonDefault(default_value, arena); |
| } |
| |
| // Similar to Release, but ptr_ cannot be the default_value. |
| inline ::std::string* ReleaseNonDefault( |
| const ::std::string* default_value, ::google::protobuf::Arena* arena) { |
| GOOGLE_DCHECK(!IsDefault(default_value)); |
| ::std::string* released = NULL; |
| if (arena != NULL) { |
| // ptr_ is owned by the arena. |
| released = new ::std::string; |
| released->swap(*ptr_); |
| } else { |
| released = ptr_; |
| } |
| ptr_ = const_cast< ::std::string* >(default_value); |
| return released; |
| } |
| |
| // UnsafeArenaRelease returns a ::std::string*, but it may be arena-owned (i.e. |
| // have its destructor already registered) if arena != NULL. If the field was |
| // not set, this returns NULL. This method clears this field back to NULL |
| // state. Used to implement unsafe_arena_release_<field>() methods on |
| // generated classes. |
| inline ::std::string* UnsafeArenaRelease(const ::std::string* default_value, |
| ::google::protobuf::Arena* /* arena */) { |
| if (ptr_ == default_value) { |
| return NULL; |
| } |
| ::std::string* released = ptr_; |
| ptr_ = const_cast< ::std::string* >(default_value); |
| return released; |
| } |
| |
| // Takes a string that is heap-allocated, and takes ownership. The string's |
| // destructor is registered with the arena. Used to implement |
| // set_allocated_<field> in generated classes. |
| inline void SetAllocated(const ::std::string* default_value, |
| ::std::string* value, ::google::protobuf::Arena* arena) { |
| if (arena == NULL && ptr_ != default_value) { |
| Destroy(default_value, arena); |
| } |
| if (value != NULL) { |
| ptr_ = value; |
| if (arena != NULL) { |
| arena->Own(value); |
| } |
| } else { |
| ptr_ = const_cast< ::std::string* >(default_value); |
| } |
| } |
| |
| // Takes a string that has lifetime equal to the arena's lifetime. The arena |
| // must be non-null. It is safe only to pass this method a value returned by |
| // UnsafeArenaRelease() on another field of a message in the same arena. Used |
| // to implement unsafe_arena_set_allocated_<field> in generated classes. |
| inline void UnsafeArenaSetAllocated(const ::std::string* default_value, |
| ::std::string* value, |
| ::google::protobuf::Arena* /* arena */) { |
| if (value != NULL) { |
| ptr_ = value; |
| } else { |
| ptr_ = const_cast< ::std::string* >(default_value); |
| } |
| } |
| |
| // Swaps internal pointers. Arena-safety semantics: this is guarded by the |
| // logic in Swap()/UnsafeArenaSwap() at the message level, so this method is |
| // 'unsafe' if called directly. |
| GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE void Swap(ArenaStringPtr* other) { |
| std::swap(ptr_, other->ptr_); |
| } |
| GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE void Swap( |
| ArenaStringPtr* other, const ::std::string* default_value, Arena* arena) { |
| #ifndef NDEBUG |
| // For debug builds, we swap the contents of the string, rather than the |
| // string instances themselves. This invalidates previously taken const |
| // references that are (per our documentation) invalidated by calling Swap() |
| // on the message. |
| // |
| // If both strings are the default_value, swapping is uninteresting. |
| // Otherwise, we use ArenaStringPtr::Mutable() to access the string, to |
| // ensure that we do not try to mutate default_value itself. |
| if (IsDefault(default_value) && other->IsDefault(default_value)) { |
| return; |
| } |
| |
| ::std::string* this_ptr = Mutable(default_value, arena); |
| ::std::string* other_ptr = other->Mutable(default_value, arena); |
| |
| this_ptr->swap(*other_ptr); |
| #else |
| std::swap(ptr_, other->ptr_); |
| #endif |
| } |
| |
| // Frees storage (if not on an arena). |
| inline void Destroy(const ::std::string* default_value, |
| ::google::protobuf::Arena* arena) { |
| if (arena == NULL && ptr_ != default_value) { |
| delete ptr_; |
| } |
| } |
| |
| // Clears content, but keeps allocated string if arena != NULL, to avoid the |
| // overhead of heap operations. After this returns, the content (as seen by |
| // the user) will always be the empty string. Assumes that |default_value| |
| // is an empty string. |
| inline void ClearToEmpty(const ::std::string* default_value, |
| ::google::protobuf::Arena* /* arena */) { |
| if (ptr_ == default_value) { |
| // Already set to default (which is empty) -- do nothing. |
| } else { |
| ptr_->clear(); |
| } |
| } |
| |
| // Clears content, assuming that the current value is not the empty string |
| // default. |
| inline void ClearNonDefaultToEmpty() { |
| ptr_->clear(); |
| } |
| inline void ClearNonDefaultToEmptyNoArena() { |
| ptr_->clear(); |
| } |
| |
| // Clears content, but keeps allocated string if arena != NULL, to avoid the |
| // overhead of heap operations. After this returns, the content (as seen by |
| // the user) will always be equal to |default_value|. |
| inline void ClearToDefault(const ::std::string* default_value, |
| ::google::protobuf::Arena* /* arena */) { |
| if (ptr_ == default_value) { |
| // Already set to default -- do nothing. |
| } else { |
| // Have another allocated string -- rather than throwing this away and |
| // resetting ptr_ to the canonical default string instance, we just reuse |
| // this instance. |
| *ptr_ = *default_value; |
| } |
| } |
| |
| // Called from generated code / reflection runtime only. Resets value to point |
| // to a default string pointer, with the semantics that this ArenaStringPtr |
| // does not own the pointed-to memory. Disregards initial value of ptr_ (so |
| // this is the *ONLY* safe method to call after construction or when |
| // reinitializing after becoming the active field in a oneof union). |
| inline void UnsafeSetDefault(const ::std::string* default_value) { |
| // Casting away 'const' is safe here: accessors ensure that ptr_ is only |
| // returned as a const if it is equal to default_value. |
| ptr_ = const_cast< ::std::string* >(default_value); |
| } |
| |
| // The 'NoArena' variants of methods below assume arena == NULL and are |
| // optimized to provide very little overhead relative to a raw string pointer |
| // (while still being in-memory compatible with other code that assumes |
| // ArenaStringPtr). Note the invariant that a class instance that has only |
| // ever been mutated by NoArena methods must *only* be in the String state |
| // (i.e., tag bits are not used), *NEVER* ArenaString. This allows all |
| // tagged-pointer manipulations to be avoided. |
| inline void SetNoArena(const ::std::string* default_value, |
| const ::std::string& value) { |
| if (ptr_ == default_value) { |
| CreateInstanceNoArena(&value); |
| } else { |
| *ptr_ = value; |
| } |
| } |
| |
| #if LANG_CXX11 |
| void SetNoArena(const ::std::string* default_value, ::std::string&& value) { |
| if (IsDefault(default_value)) { |
| ptr_ = new ::std::string(std::move(value)); |
| } else { |
| *ptr_ = std::move(value); |
| } |
| } |
| #endif |
| |
| void AssignWithDefault(const ::std::string* default_value, ArenaStringPtr value); |
| |
| inline const ::std::string& GetNoArena() const { return *ptr_; } |
| |
| inline ::std::string* MutableNoArena(const ::std::string* default_value) { |
| if (ptr_ == default_value) { |
| CreateInstanceNoArena(default_value); |
| } |
| return ptr_; |
| } |
| |
| inline ::std::string* ReleaseNoArena(const ::std::string* default_value) { |
| if (ptr_ == default_value) { |
| return NULL; |
| } else { |
| return ReleaseNonDefaultNoArena(default_value); |
| } |
| } |
| |
| inline ::std::string* ReleaseNonDefaultNoArena( |
| const ::std::string* default_value) { |
| GOOGLE_DCHECK(!IsDefault(default_value)); |
| ::std::string* released = ptr_; |
| ptr_ = const_cast< ::std::string* >(default_value); |
| return released; |
| } |
| |
| |
| inline void SetAllocatedNoArena(const ::std::string* default_value, |
| ::std::string* value) { |
| if (ptr_ != default_value) { |
| delete ptr_; |
| } |
| if (value != NULL) { |
| ptr_ = value; |
| } else { |
| ptr_ = const_cast< ::std::string* >(default_value); |
| } |
| } |
| |
| inline void DestroyNoArena(const ::std::string* default_value) { |
| if (ptr_ != default_value) { |
| delete ptr_; |
| } |
| } |
| |
| inline void ClearToEmptyNoArena(const ::std::string* default_value) { |
| if (ptr_ == default_value) { |
| // Nothing: already equal to default (which is the empty string). |
| } else { |
| ptr_->clear(); |
| } |
| } |
| |
| inline void ClearToDefaultNoArena(const ::std::string* default_value) { |
| if (ptr_ == default_value) { |
| // Nothing: already set to default. |
| } else { |
| // Reuse existing allocated instance. |
| *ptr_ = *default_value; |
| } |
| } |
| |
| // Internal accessor used only at parse time to provide direct access to the |
| // raw pointer from the shared parse routine (in the non-arenas case). The |
| // parse routine does the string allocation in order to save code size in the |
| // generated parsing code. |
| inline ::std::string** UnsafeRawStringPointer() { |
| return &ptr_; |
| } |
| |
| inline bool IsDefault(const ::std::string* default_value) const { |
| return ptr_ == default_value; |
| } |
| |
| // Internal accessors!!!! |
| void UnsafeSetTaggedPointer(TaggedPtr< ::std::string> value) { |
| ptr_ = value.Get(); |
| } |
| // Generated code only! An optimization, in certain cases the generated |
| // code is certain we can obtain a string with no default checks and |
| // tag tests. |
| ::std::string* UnsafeMutablePointer() { return ptr_; } |
| |
| private: |
| ::std::string* ptr_; |
| |
| GOOGLE_PROTOBUF_ATTRIBUTE_NOINLINE |
| void CreateInstance(::google::protobuf::Arena* arena, |
| const ::std::string* initial_value) { |
| GOOGLE_DCHECK(initial_value != NULL); |
| // uses "new ::std::string" when arena is nullptr |
| ptr_ = Arena::Create< ::std::string >(arena, *initial_value); |
| } |
| GOOGLE_PROTOBUF_ATTRIBUTE_NOINLINE |
| void CreateInstanceNoArena(const ::std::string* initial_value) { |
| GOOGLE_DCHECK(initial_value != NULL); |
| ptr_ = new ::std::string(*initial_value); |
| } |
| }; |
| |
| } // namespace internal |
| } // namespace protobuf |
| |
| |
| |
| namespace protobuf { |
| namespace internal { |
| |
| inline void ArenaStringPtr::AssignWithDefault(const ::std::string* default_value, |
| ArenaStringPtr value) { |
| const ::std::string* me = *UnsafeRawStringPointer(); |
| const ::std::string* other = *value.UnsafeRawStringPointer(); |
| // If the pointers are the same then do nothing. |
| if (me != other) { |
| SetNoArena(default_value, value.GetNoArena()); |
| } |
| } |
| |
| } // namespace internal |
| } // namespace protobuf |
| |
| } // namespace google |
| #endif // GOOGLE_PROTOBUF_ARENASTRING_H__ |