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// AsmJit - Machine code generation for C++
//
// * Official AsmJit Home Page: https://asmjit.com
// * Official Github Repository: https://github.com/asmjit/asmjit
//
// Copyright (c) 2008-2020 The AsmJit Authors
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
#ifndef ASMJIT_CORE_SMALLSTRING_H_INCLUDED
#define ASMJIT_CORE_SMALLSTRING_H_INCLUDED
#include "../core/globals.h"
#include "../core/zone.h"
ASMJIT_BEGIN_NAMESPACE
//! \addtogroup asmjit_zone
//! \{
// ============================================================================
// [asmjit::ZoneStringBase]
// ============================================================================
//! A helper class used by \ref ZoneString implementation.
struct ZoneStringBase {
union {
struct {
uint32_t _size;
char _embedded[sizeof(void*) * 2 - 4];
};
struct {
void* _dummy;
char* _external;
};
};
inline void reset() noexcept {
_dummy = nullptr;
_external = nullptr;
}
Error setData(Zone* zone, uint32_t maxEmbeddedSize, const char* str, size_t size) noexcept {
if (size == SIZE_MAX)
size = strlen(str);
if (size <= maxEmbeddedSize) {
memcpy(_embedded, str, size);
_embedded[size] = '\0';
}
else {
char* external = static_cast<char*>(zone->dup(str, size, true));
if (ASMJIT_UNLIKELY(!external))
return DebugUtils::errored(kErrorOutOfMemory);
_external = external;
}
_size = uint32_t(size);
return kErrorOk;
}
};
// ============================================================================
// [asmjit::ZoneString<N>]
// ============================================================================
//! A string template that can be zone allocated.
//!
//! Helps with creating strings that can be either statically allocated if they
//! are small, or externally allocated in case their size exceeds the limit.
//! The `N` represents the size of the whole `ZoneString` structure, based on
//! that size the maximum size of the internal buffer is determined.
template<size_t N>
class ZoneString {
public:
static constexpr uint32_t kWholeSize =
(N > sizeof(ZoneStringBase)) ? uint32_t(N) : uint32_t(sizeof(ZoneStringBase));
static constexpr uint32_t kMaxEmbeddedSize = kWholeSize - 5;
union {
ZoneStringBase _base;
char _wholeData[kWholeSize];
};
//! \name Construction & Destruction
//! \{
inline ZoneString() noexcept { reset(); }
inline void reset() noexcept { _base.reset(); }
//! \}
//! \name Accessors
//! \{
//! Tests whether the string is empty.
inline bool empty() const noexcept { return _base._size == 0; }
//! Returns the string data.
inline const char* data() const noexcept { return _base._size <= kMaxEmbeddedSize ? _base._embedded : _base._external; }
//! Returns the string size.
inline uint32_t size() const noexcept { return _base._size; }
//! Tests whether the string is embedded (e.g. no dynamically allocated).
inline bool isEmbedded() const noexcept { return _base._size <= kMaxEmbeddedSize; }
//! Copies a new `data` of the given `size` to the string.
//!
//! If the `size` exceeds the internal buffer the given `zone` will be
//! used to duplicate the data, otherwise the internal buffer will be
//! used as a storage.
inline Error setData(Zone* zone, const char* data, size_t size) noexcept {
return _base.setData(zone, kMaxEmbeddedSize, data, size);
}
//! \}
};
//! \}
ASMJIT_END_NAMESPACE
#endif // ASMJIT_CORE_SMALLSTRING_H_INCLUDED
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