Defcon/hook_lib/asmjit/core/zonestring.h

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2023-11-26 08:54:06 -05:00
// This file is part of AsmJit project <https://asmjit.com>
//
// See asmjit.h or LICENSE.md for license and copyright information
// SPDX-License-Identifier: Zlib
#ifndef ASMJIT_CORE_ZONESTRING_H_INCLUDED
#define ASMJIT_CORE_ZONESTRING_H_INCLUDED
#include "../core/globals.h"
#include "../core/zone.h"
ASMJIT_BEGIN_NAMESPACE
//! \addtogroup asmjit_zone
//! \{
//! 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;
}
};
//! 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:
//! \name Constants
//! \{
enum : uint32_t {
kWholeSize = (N > sizeof(ZoneStringBase)) ? uint32_t(N) : uint32_t(sizeof(ZoneStringBase)),
kMaxEmbeddedSize = kWholeSize - 5
};
//! \}
//! \name Members
//! \{
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_ZONESTRING_H_INCLUDED