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Diffstat (limited to 'third_party/protobuf/3.6.0/src/google/protobuf/arenastring.h')
| -rw-r--r-- | third_party/protobuf/3.6.0/src/google/protobuf/arenastring.h | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/third_party/protobuf/3.6.0/src/google/protobuf/arenastring.h b/third_party/protobuf/3.6.0/src/google/protobuf/arenastring.h new file mode 100644 index 0000000000..168fc972b8 --- /dev/null +++ b/third_party/protobuf/3.6.0/src/google/protobuf/arenastring.h @@ -0,0 +1,403 @@ +// 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__ |