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mdbx.h++
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mdbx.h++
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/// \file mdbx.h++
/// \brief The libmdbx C++ API header file.
///
/// \author Copyright (c) 2020-2022, Leonid Yuriev <leo@yuriev.ru>.
/// \copyright SPDX-License-Identifier: Apache-2.0
///
/// Tested with:
/// - Elbrus LCC >= 1.23 (http://www.mcst.ru/lcc);
/// - GNU C++ >= 4.8;
/// - clang >= 3.9;
/// - MSVC >= 14.0 (Visual Studio 2015),
/// but 19.2x could hang due optimizer bug;
/// - AppleClang, but without C++20 concepts.
///
#pragma once
/* Workaround for modern libstdc++ with CLANG < 4.x */
#if defined(__SIZEOF_INT128__) && !defined(__GLIBCXX_TYPE_INT_N_0) && \
defined(__clang__) && __clang_major__ < 4
#define __GLIBCXX_BITSIZE_INT_N_0 128
#define __GLIBCXX_TYPE_INT_N_0 __int128
#endif /* Workaround for modern libstdc++ with CLANG < 4.x */
#if !defined(__cplusplus) || __cplusplus < 201103L
#if !defined(_MSC_VER) || _MSC_VER < 1900
#error "C++11 compiler or better is required"
#elif _MSC_VER >= 1910
#error \
"Please add `/Zc:__cplusplus` to MSVC compiler options to enforce it conform ISO C++"
#endif /* MSVC is mad and don't define __cplusplus properly */
#endif /* __cplusplus < 201103L */
#if (defined(_WIN32) || defined(_WIN64)) && MDBX_WITHOUT_MSVC_CRT
#error \
"CRT is required for C++ API, the MDBX_WITHOUT_MSVC_CRT option must be disabled"
#endif /* Windows */
#ifndef __has_include
#define __has_include(header) (0)
#endif /* __has_include */
#if __has_include(<version>)
#include <version>
#endif /* <version> */
/* Disable min/max macros from C' headers */
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <algorithm> // for std::min/max
#include <cassert> // for assert()
#include <climits> // for CHAR_BIT
#include <cstring> // for std::strlen, str:memcmp
#include <exception> // for std::exception_ptr
#include <ostream> // for std::ostream
#include <sstream> // for std::ostringstream
#include <stdexcept> // for std::invalid_argument
#include <string> // for std::string
#include <type_traits> // for std::is_pod<>, etc.
#include <utility> // for std::make_pair
#include <vector> // for std::vector<> as template args
#if defined(__cpp_lib_memory_resource) && __cpp_lib_memory_resource >= 201603L
#include <memory_resource>
#endif
#if defined(__cpp_lib_string_view) && __cpp_lib_string_view >= 201606L
#include <string_view>
#endif
#if defined(__cpp_lib_filesystem) && __cpp_lib_filesystem >= 201703L
#include <filesystem>
#elif __has_include(<experimental/filesystem>)
#include <experimental/filesystem>
#endif
#include "mdbx.h"
#if (defined(__cpp_lib_bit_cast) && __cpp_lib_bit_cast >= 201806L) || \
(defined(__cpp_lib_endian) && __cpp_lib_endian >= 201907L) || \
(defined(__cpp_lib_bitops) && __cpp_lib_bitops >= 201907L) || \
(defined(__cpp_lib_int_pow2) && __cpp_lib_int_pow2 >= 202002L)
#include <bit>
#elif !(defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
defined(__ORDER_BIG_ENDIAN__))
#if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN)
#define __ORDER_LITTLE_ENDIAN__ __LITTLE_ENDIAN
#define __ORDER_BIG_ENDIAN__ __BIG_ENDIAN
#define __BYTE_ORDER__ __BYTE_ORDER
#elif defined(_BYTE_ORDER) && defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)
#define __ORDER_LITTLE_ENDIAN__ _LITTLE_ENDIAN
#define __ORDER_BIG_ENDIAN__ _BIG_ENDIAN
#define __BYTE_ORDER__ _BYTE_ORDER
#else
#define __ORDER_LITTLE_ENDIAN__ 1234
#define __ORDER_BIG_ENDIAN__ 4321
#if defined(__LITTLE_ENDIAN__) || \
(defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN)) || \
defined(__ARMEL__) || defined(__THUMBEL__) || defined(__AARCH64EL__) || \
defined(__MIPSEL__) || defined(_MIPSEL) || defined(__MIPSEL) || \
defined(_M_ARM) || defined(_M_ARM64) || defined(__e2k__) || \
defined(__elbrus_4c__) || defined(__elbrus_8c__) || defined(__bfin__) || \
defined(__BFIN__) || defined(__ia64__) || defined(_IA64) || \
defined(__IA64__) || defined(__ia64) || defined(_M_IA64) || \
defined(__itanium__) || defined(__ia32__) || defined(__CYGWIN__) || \
defined(_WIN64) || defined(_WIN32) || defined(__TOS_WIN__) || \
defined(__WINDOWS__)
#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
#elif defined(__BIG_ENDIAN__) || \
(defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)) || \
defined(__ARMEB__) || defined(__THUMBEB__) || defined(__AARCH64EB__) || \
defined(__MIPSEB__) || defined(_MIPSEB) || defined(__MIPSEB) || \
defined(__m68k__) || defined(M68000) || defined(__hppa__) || \
defined(__hppa) || defined(__HPPA__) || defined(__sparc__) || \
defined(__sparc) || defined(__370__) || defined(__THW_370__) || \
defined(__s390__) || defined(__s390x__) || defined(__SYSC_ZARCH__)
#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
#endif
#endif
#endif /* Byte Order */
#if defined(DOXYGEN) || \
defined(__cpp_constexpr) && __cpp_constexpr >= 201603L && \
((defined(_MSC_VER) && _MSC_VER >= 1915) || \
(defined(__clang__) && __clang_major__ > 5) || \
(defined(__GNUC__) && __GNUC__ > 7) || \
(!defined(__GNUC__) && !defined(__clang__) && !defined(_MSC_VER)))
#define MDBX_CXX17_CONSTEXPR constexpr
#else
#define MDBX_CXX17_CONSTEXPR inline
#endif /* MDBX_CXX17_CONSTEXPR */
#if defined(DOXYGEN) || defined(__cpp_lib_is_constant_evaluated) && \
__cpp_lib_is_constant_evaluated >= 201811L && \
defined(__cpp_lib_constexpr_string) && \
__cpp_lib_constexpr_string >= 201907L
#define MDBX_CXX20_CONSTEXPR constexpr
#else
#define MDBX_CXX20_CONSTEXPR inline
#endif /* MDBX_CXX20_CONSTEXPR */
#if defined(CONSTEXPR_ASSERT)
#define MDBX_CONSTEXPR_ASSERT(expr) CONSTEXPR_ASSERT(expr)
#elif defined NDEBUG
#define MDBX_CONSTEXPR_ASSERT(expr) void(0)
#else
#define MDBX_CONSTEXPR_ASSERT(expr) \
((expr) ? void(0) : [] { assert(!#expr); }())
#endif /* MDBX_CONSTEXPR_ASSERT */
#ifndef MDBX_LIKELY
#if defined(DOXYGEN) || \
(defined(__GNUC__) || __has_builtin(__builtin_expect)) && \
!defined(__COVERITY__)
#define MDBX_LIKELY(cond) __builtin_expect(!!(cond), 1)
#else
#define MDBX_LIKELY(x) (x)
#endif
#endif /* MDBX_LIKELY */
#ifndef MDBX_UNLIKELY
#if defined(DOXYGEN) || \
(defined(__GNUC__) || __has_builtin(__builtin_expect)) && \
!defined(__COVERITY__)
#define MDBX_UNLIKELY(cond) __builtin_expect(!!(cond), 0)
#else
#define MDBX_UNLIKELY(x) (x)
#endif
#endif /* MDBX_UNLIKELY */
#if defined(__cpp_if_constexpr) && __cpp_if_constexpr >= 201606L
#define MDBX_IF_CONSTEXPR constexpr
#else
#define MDBX_IF_CONSTEXPR
#endif /* MDBX_IF_CONSTEXPR */
#if defined(DOXYGEN) || \
(__has_cpp_attribute(fallthrough) && \
(!defined(__clang__) || __clang__ > 4)) || \
__cplusplus >= 201703L
#define MDBX_CXX17_FALLTHROUGH [[fallthrough]]
#else
#define MDBX_CXX17_FALLTHROUGH
#endif /* MDBX_CXX17_FALLTHROUGH */
#if defined(DOXYGEN) || (__has_cpp_attribute(likely) >= 201803L && \
(!defined(__GNUC__) || __GNUC__ > 9))
#define MDBX_CXX20_LIKELY [[likely]]
#else
#define MDBX_CXX20_LIKELY
#endif /* MDBX_CXX20_LIKELY */
#ifndef MDBX_CXX20_UNLIKELY
#if defined(DOXYGEN) || (__has_cpp_attribute(unlikely) >= 201803L && \
(!defined(__GNUC__) || __GNUC__ > 9))
#define MDBX_CXX20_UNLIKELY [[unlikely]]
#else
#define MDBX_CXX20_UNLIKELY
#endif
#endif /* MDBX_CXX20_UNLIKELY */
#ifndef MDBX_CXX20_CONCEPT
#if defined(DOXYGEN) || \
(defined(__cpp_concepts) && __cpp_concepts >= 201907L && \
(!defined(__clang__) || \
(__clang_major__ >= 12 && !defined(__APPLE__) && \
!defined(__ANDROID_API__)) || \
__clang_major__ >= \
/* Hope Apple will fix concepts in AppleClang 14 */ 14))
#define MDBX_CXX20_CONCEPT(CONCEPT, NAME) CONCEPT NAME
#else
#define MDBX_CXX20_CONCEPT(CONCEPT, NAME) typename NAME
#endif
#endif /* MDBX_CXX20_CONCEPT */
#ifndef MDBX_ASSERT_CXX20_CONCEPT_SATISFIED
#if defined(DOXYGEN) || \
(defined(__cpp_concepts) && __cpp_concepts >= 201907L && \
(!defined(__clang__) || \
(__clang_major__ >= 12 && !defined(__APPLE__) && \
!defined(__ANDROID_API__)) || \
__clang_major__ >= \
/* Hope Apple will fix concepts in AppleClang 14 */ 14))
#define MDBX_ASSERT_CXX20_CONCEPT_SATISFIED(CONCEPT, TYPE) \
static_assert(CONCEPT<TYPE>)
#else
#define MDBX_ASSERT_CXX20_CONCEPT_SATISFIED(CONCEPT, NAME) \
static_assert(true, MDBX_STRINGIFY(CONCEPT) "<" MDBX_STRINGIFY(TYPE) ">")
#endif
#endif /* MDBX_ASSERT_CXX20_CONCEPT_SATISFIED */
#ifdef _MSC_VER
#pragma warning(push, 4)
#pragma warning(disable : 4127) /* conditional expression is constant */
#pragma warning(disable : 4251) /* 'std::FOO' needs to have dll-interface to \
be used by clients of 'mdbx::BAR' */
#pragma warning(disable : 4275) /* non dll-interface 'std::FOO' used as \
base for dll-interface 'mdbx::BAR' */
/* MSVC is mad and can generate this warning for its own intermediate
* automatically generated code, which becomes unreachable after some kinds of
* optimization (copy elision, etc). */
#pragma warning(disable : 4702) /* unreachable code */
#endif /* _MSC_VER (warnings) */
//------------------------------------------------------------------------------
/// \defgroup cxx_api C++ API
/// @{
namespace mdbx {
// Functions whose signature depends on the `mdbx::byte` type
// must be strictly defined as inline!
#if defined(DOXYGEN) || (defined(__cpp_char8_t) && __cpp_char8_t >= 201811)
// To enable all kinds of an compiler optimizations we use a byte-like type
// that don't presumes aliases for pointers as does the `char` type and its
// derivatives/typedefs.
// Please see https://github.com/erthink/libmdbx/issues/263
// for reasoning of the use of `char8_t` type and switching to `__restrict__`.
using byte = char8_t;
#else
// Avoid `std::byte` since it doesn't add features but inconvenient
// restrictions.
using byte = unsigned char;
#endif /* __cpp_char8_t >= 201811*/
#if defined(__cpp_lib_endian) && __cpp_lib_endian >= 201907L
using endian = ::std::endian;
#elif defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
defined(__ORDER_BIG_ENDIAN__)
enum class endian {
little = __ORDER_LITTLE_ENDIAN__,
big = __ORDER_BIG_ENDIAN__,
native = __BYTE_ORDER__
};
#else
#error \
"Please use a C++ compiler provides byte order information or C++20 support"
#endif /* Byte Order enum */
/// \copydoc MDBX_version_info
using version_info = ::MDBX_version_info;
/// \brief Returns libmdbx version information.
MDBX_CXX11_CONSTEXPR const version_info &get_version() noexcept;
/// \copydoc MDBX_build_info
using build_info = ::MDBX_build_info;
/// \brief Returns libmdbx build information.
MDBX_CXX11_CONSTEXPR const build_info &get_build() noexcept;
/// \brief constexpr-compatible strlen().
static MDBX_CXX17_CONSTEXPR size_t strlen(const char *c_str) noexcept;
/// \brief Legacy default allocator
/// but it is recommended to use \ref polymorphic_allocator.
using legacy_allocator = ::std::string::allocator_type;
struct slice;
struct default_capacity_policy;
template <class ALLOCATOR = legacy_allocator,
class CAPACITY_POLICY = default_capacity_policy>
class buffer;
class env;
class env_managed;
class txn;
class txn_managed;
class cursor;
class cursor_managed;
#if defined(DOXYGEN) || \
(defined(__cpp_lib_memory_resource) && \
__cpp_lib_memory_resource >= 201603L && _GLIBCXX_USE_CXX11_ABI)
/// \brief Default polymorphic allocator for modern code.
using polymorphic_allocator = ::std::pmr::string::allocator_type;
#endif /* __cpp_lib_memory_resource >= 201603L */
/// \brief Default singe-byte string.
template <class ALLOCATOR = legacy_allocator>
using string = ::std::basic_string<char, ::std::char_traits<char>, ALLOCATOR>;
using filehandle = ::mdbx_filehandle_t;
#if defined(DOXYGEN) || \
(defined(__cpp_lib_filesystem) && __cpp_lib_filesystem >= 201703L && \
(!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || \
__MAC_OS_X_VERSION_MIN_REQUIRED >= 101500) && \
(!defined(__IPHONE_OS_VERSION_MIN_REQUIRED) || \
__IPHONE_OS_VERSION_MIN_REQUIRED >= 130100))
namespace filesystem = ::std::filesystem;
#define MDBX_STD_FILESYSTEM_PATH ::mdbx::filesystem::path
#elif defined(__cpp_lib_experimental_filesystem) && \
__cpp_lib_experimental_filesystem >= 201406L
namespace filesystem = ::std::experimental::filesystem;
#define MDBX_STD_FILESYSTEM_PATH ::mdbx::filesystem::path
#endif /* MDBX_STD_FILESYSTEM_PATH */
#ifdef MDBX_STD_FILESYSTEM_PATH
using path = MDBX_STD_FILESYSTEM_PATH;
#elif defined(_WIN32) || defined(_WIN64)
using path = ::std::wstring;
#else
using path = ::std::string;
#endif /* mdbx::path */
/// \brief Transfers C++ exceptions thru C callbacks.
/// \details Implements saving exceptions before returning
/// from an C++'s environment to the intermediate C code and re-throwing after
/// returning from C to the C++'s environment.
class LIBMDBX_API_TYPE exception_thunk {
::std::exception_ptr captured_;
public:
exception_thunk() noexcept = default;
exception_thunk(const exception_thunk &) = delete;
exception_thunk(exception_thunk &&) = delete;
exception_thunk &operator=(const exception_thunk &) = delete;
exception_thunk &operator=(exception_thunk &&) = delete;
inline bool is_clean() const noexcept;
inline void capture() noexcept;
inline void rethrow_captured() const;
};
/// \brief Implements error information and throwing corresponding exceptions.
class LIBMDBX_API_TYPE error {
MDBX_error_t code_;
inline error &operator=(MDBX_error_t error_code) noexcept;
public:
MDBX_CXX11_CONSTEXPR error(MDBX_error_t error_code) noexcept;
error(const error &) = default;
error(error &&) = default;
error &operator=(const error &) = default;
error &operator=(error &&) = default;
MDBX_CXX11_CONSTEXPR friend bool operator==(const error &a,
const error &b) noexcept;
MDBX_CXX11_CONSTEXPR friend bool operator!=(const error &a,
const error &b) noexcept;
MDBX_CXX11_CONSTEXPR bool is_success() const noexcept;
MDBX_CXX11_CONSTEXPR bool is_result_true() const noexcept;
MDBX_CXX11_CONSTEXPR bool is_result_false() const noexcept;
MDBX_CXX11_CONSTEXPR bool is_failure() const noexcept;
/// \brief Returns error code.
MDBX_CXX11_CONSTEXPR MDBX_error_t code() const noexcept;
/// \brief Returns message for MDBX's errors only and "SYSTEM" for others.
const char *what() const noexcept;
/// \brief Returns message for any errors.
::std::string message() const;
/// \brief Returns true for MDBX's errors.
MDBX_CXX11_CONSTEXPR bool is_mdbx_error() const noexcept;
/// \brief Panics on unrecoverable errors inside destructors etc.
[[noreturn]] void panic(const char *context_where_when,
const char *func_who_what) const noexcept;
[[noreturn]] void throw_exception() const;
[[noreturn]] static inline void throw_exception(int error_code);
inline void throw_on_failure() const;
inline void success_or_throw() const;
inline void success_or_throw(const exception_thunk &) const;
inline void panic_on_failure(const char *context_where,
const char *func_who) const noexcept;
inline void success_or_panic(const char *context_where,
const char *func_who) const noexcept;
static inline void throw_on_nullptr(const void *ptr, MDBX_error_t error_code);
static inline void success_or_throw(MDBX_error_t error_code);
static void success_or_throw(int error_code) {
success_or_throw(static_cast<MDBX_error_t>(error_code));
}
static inline void throw_on_failure(int error_code);
static inline bool boolean_or_throw(int error_code);
static inline void success_or_throw(int error_code, const exception_thunk &);
static inline void panic_on_failure(int error_code, const char *context_where,
const char *func_who) noexcept;
static inline void success_or_panic(int error_code, const char *context_where,
const char *func_who) noexcept;
};
/// \brief Base class for all libmdbx's exceptions that are corresponds
/// to libmdbx errors.
///
/// \see MDBX_error_t
class LIBMDBX_API_TYPE exception : public ::std::runtime_error {
using base = ::std::runtime_error;
::mdbx::error error_;
public:
exception(const ::mdbx::error &) noexcept;
exception(const exception &) = default;
exception(exception &&) = default;
exception &operator=(const exception &) = default;
exception &operator=(exception &&) = default;
virtual ~exception() noexcept;
const ::mdbx::error error() const noexcept { return error_; }
};
/// \brief Fatal exception that lead termination anyway
/// in dangerous unrecoverable cases.
class LIBMDBX_API_TYPE fatal : public exception {
using base = exception;
public:
fatal(const ::mdbx::error &) noexcept;
fatal(const exception &src) noexcept : fatal(src.error()) {}
fatal(exception &&src) noexcept : fatal(src.error()) {}
fatal(const fatal &src) noexcept : fatal(src.error()) {}
fatal(fatal &&src) noexcept : fatal(src.error()) {}
fatal &operator=(fatal &&) = default;
fatal &operator=(const fatal &) = default;
virtual ~fatal() noexcept;
};
#define MDBX_DECLARE_EXCEPTION(NAME) \
struct LIBMDBX_API_TYPE NAME : public exception { \
NAME(const ::mdbx::error &); \
virtual ~NAME() noexcept; \
}
MDBX_DECLARE_EXCEPTION(bad_map_id);
MDBX_DECLARE_EXCEPTION(bad_transaction);
MDBX_DECLARE_EXCEPTION(bad_value_size);
MDBX_DECLARE_EXCEPTION(db_corrupted);
MDBX_DECLARE_EXCEPTION(db_full);
MDBX_DECLARE_EXCEPTION(db_invalid);
MDBX_DECLARE_EXCEPTION(db_too_large);
MDBX_DECLARE_EXCEPTION(db_unable_extend);
MDBX_DECLARE_EXCEPTION(db_version_mismatch);
MDBX_DECLARE_EXCEPTION(db_wanna_write_for_recovery);
MDBX_DECLARE_EXCEPTION(incompatible_operation);
MDBX_DECLARE_EXCEPTION(internal_page_full);
MDBX_DECLARE_EXCEPTION(internal_problem);
MDBX_DECLARE_EXCEPTION(key_exists);
MDBX_DECLARE_EXCEPTION(key_mismatch);
MDBX_DECLARE_EXCEPTION(max_maps_reached);
MDBX_DECLARE_EXCEPTION(max_readers_reached);
MDBX_DECLARE_EXCEPTION(multivalue);
MDBX_DECLARE_EXCEPTION(no_data);
MDBX_DECLARE_EXCEPTION(not_found);
MDBX_DECLARE_EXCEPTION(operation_not_permitted);
MDBX_DECLARE_EXCEPTION(permission_denied_or_not_writeable);
MDBX_DECLARE_EXCEPTION(reader_slot_busy);
MDBX_DECLARE_EXCEPTION(remote_media);
MDBX_DECLARE_EXCEPTION(something_busy);
MDBX_DECLARE_EXCEPTION(thread_mismatch);
MDBX_DECLARE_EXCEPTION(transaction_full);
MDBX_DECLARE_EXCEPTION(transaction_overlapping);
#undef MDBX_DECLARE_EXCEPTION
[[noreturn]] LIBMDBX_API void throw_too_small_target_buffer();
[[noreturn]] LIBMDBX_API void throw_max_length_exceeded();
[[noreturn]] LIBMDBX_API void throw_out_range();
[[noreturn]] LIBMDBX_API void throw_allocators_mismatch();
static MDBX_CXX14_CONSTEXPR size_t check_length(size_t bytes);
static MDBX_CXX14_CONSTEXPR size_t check_length(size_t headroom,
size_t payload);
static MDBX_CXX14_CONSTEXPR size_t check_length(size_t headroom, size_t payload,
size_t tailroom);
static MDBX_CXX17_CONSTEXPR size_t strlen(const char *c_str) noexcept;
static MDBX_CXX20_CONSTEXPR void *memcpy(void *dest, const void *src,
size_t bytes) noexcept;
//------------------------------------------------------------------------------
#if defined(DOXYGEN) || \
(defined(__cpp_concepts) && __cpp_concepts >= 201907L && \
(!defined(__clang__) || \
(__clang_major__ >= 12 && !defined(__APPLE__) && \
!defined(__ANDROID_API__)) || \
__clang_major__ >= \
/* Hope Apple will fix concepts in AppleClang 14 */ 14))
template <typename T>
concept MutableByteProducer = requires(T a, char array[42]) {
{ a.is_empty() } -> std::same_as<bool>;
{ a.envisage_result_length() } -> std::same_as<size_t>;
{ a.write_bytes(&array[0], size_t(42)) } -> std::same_as<char *>;
};
template <typename T>
concept ImmutableByteProducer = requires(const T &a, char array[42]) {
{ a.is_empty() } -> std::same_as<bool>;
{ a.envisage_result_length() } -> std::same_as<size_t>;
{ a.write_bytes(&array[0], size_t(42)) } -> std::same_as<char *>;
};
template <typename T>
concept SliceTranscoder = ImmutableByteProducer<T> &&
requires(const slice &source, const T &a) {
T(source);
{ a.is_erroneous() } -> std::same_as<bool>;
};
#endif /* __cpp_concepts >= 201907L*/
template <class ALLOCATOR = legacy_allocator,
typename CAPACITY_POLICY = default_capacity_policy,
MDBX_CXX20_CONCEPT(MutableByteProducer, PRODUCER)>
inline buffer<ALLOCATOR, CAPACITY_POLICY>
make_buffer(PRODUCER &producer, const ALLOCATOR &allocator = ALLOCATOR());
template <class ALLOCATOR = legacy_allocator,
typename CAPACITY_POLICY = default_capacity_policy,
MDBX_CXX20_CONCEPT(ImmutableByteProducer, PRODUCER)>
inline buffer<ALLOCATOR, CAPACITY_POLICY>
make_buffer(const PRODUCER &producer, const ALLOCATOR &allocator = ALLOCATOR());
template <class ALLOCATOR = legacy_allocator,
MDBX_CXX20_CONCEPT(MutableByteProducer, PRODUCER)>
inline string<ALLOCATOR> make_string(PRODUCER &producer,
const ALLOCATOR &allocator = ALLOCATOR());
template <class ALLOCATOR = legacy_allocator,
MDBX_CXX20_CONCEPT(ImmutableByteProducer, PRODUCER)>
inline string<ALLOCATOR> make_string(const PRODUCER &producer,
const ALLOCATOR &allocator = ALLOCATOR());
/// \brief References a data located outside the slice.
///
/// The `slice` is similar in many ways to `std::string_view`, but it
/// implements specific capabilities and manipulates with bytes but
/// not a characters.
///
/// \copydetails MDBX_val
struct LIBMDBX_API_TYPE slice : public ::MDBX_val {
/// \todo slice& operator<<(slice&, ...) for reading
/// \todo key-to-value (parse/unpack) functions
/// \todo template<class X> key(X); for decoding keys while reading
enum { max_length = MDBX_MAXDATASIZE };
/// \brief Create an empty slice.
MDBX_CXX11_CONSTEXPR slice() noexcept;
/// \brief Create a slice that refers to [0,bytes-1] of memory bytes pointed
/// by ptr.
MDBX_CXX14_CONSTEXPR slice(const void *ptr, size_t bytes);
/// \brief Create a slice that refers to [begin,end] of memory bytes.
MDBX_CXX14_CONSTEXPR slice(const void *begin, const void *end);
/// \brief Create a slice that refers to text[0,strlen(text)-1].
template <size_t SIZE>
MDBX_CXX14_CONSTEXPR slice(const char (&text)[SIZE]) : slice(text, SIZE - 1) {
MDBX_CONSTEXPR_ASSERT(SIZE > 0 && text[SIZE - 1] == '\0');
}
/// \brief Create a slice that refers to c_str[0,strlen(c_str)-1].
explicit MDBX_CXX17_CONSTEXPR slice(const char *c_str);
/// \brief Create a slice that refers to the contents of "str".
/// \note 'explicit' to avoid reference to the temporary std::string instance.
template <class CHAR, class T, class A>
explicit MDBX_CXX20_CONSTEXPR
slice(const ::std::basic_string<CHAR, T, A> &str)
: slice(str.data(), str.length() * sizeof(CHAR)) {}
MDBX_CXX14_CONSTEXPR slice(const MDBX_val &src);
MDBX_CXX11_CONSTEXPR slice(const slice &) noexcept = default;
MDBX_CXX14_CONSTEXPR slice(MDBX_val &&src);
MDBX_CXX14_CONSTEXPR slice(slice &&src) noexcept;
#if defined(DOXYGEN) || \
(defined(__cpp_lib_string_view) && __cpp_lib_string_view >= 201606L)
/// \brief Create a slice that refers to the same contents as "string_view"
template <class CHAR, class T>
MDBX_CXX14_CONSTEXPR slice(const ::std::basic_string_view<CHAR, T> &sv)
: slice(sv.data(), sv.data() + sv.length()) {}
template <class CHAR, class T>
slice(::std::basic_string_view<CHAR, T> &&sv) : slice(sv) {
sv = {};
}
#endif /* __cpp_lib_string_view >= 201606L */
template <size_t SIZE>
static MDBX_CXX14_CONSTEXPR slice wrap(const char (&text)[SIZE]) {
return slice(text);
}
template <typename POD>
MDBX_CXX14_CONSTEXPR static slice wrap(const POD &pod) {
static_assert(::std::is_standard_layout<POD>::value &&
!::std::is_pointer<POD>::value,
"Must be a standard layout type!");
return slice(&pod, sizeof(pod));
}
inline slice &assign(const void *ptr, size_t bytes);
inline slice &assign(const slice &src) noexcept;
inline slice &assign(const ::MDBX_val &src);
inline slice &assign(slice &&src) noexcept;
inline slice &assign(::MDBX_val &&src);
inline slice &assign(const void *begin, const void *end);
template <class CHAR, class T, class ALLOCATOR>
slice &assign(const ::std::basic_string<CHAR, T, ALLOCATOR> &str) {
return assign(str.data(), str.length() * sizeof(CHAR));
}
inline slice &assign(const char *c_str);
#if defined(DOXYGEN) || \
(defined(__cpp_lib_string_view) && __cpp_lib_string_view >= 201606L)
template <class CHAR, class T>
slice &assign(const ::std::basic_string_view<CHAR, T> &view) {
return assign(view.begin(), view.end());
}
template <class CHAR, class T>
slice &assign(::std::basic_string_view<CHAR, T> &&view) {
assign(view);
view = {};
return *this;
}
#endif /* __cpp_lib_string_view >= 201606L */
slice &operator=(const slice &) noexcept = default;
inline slice &operator=(slice &&src) noexcept;
inline slice &operator=(::MDBX_val &&src);
#if defined(DOXYGEN) || \
(defined(__cpp_lib_string_view) && __cpp_lib_string_view >= 201606L)
template <class CHAR, class T>
slice &operator=(const ::std::basic_string_view<CHAR, T> &view) {
return assign(view);
}
template <class CHAR, class T>
slice &operator=(::std::basic_string_view<CHAR, T> &&view) {
return assign(view);
}
/// \brief Return a string_view that references the same data as this slice.
template <class CHAR = char, class T = ::std::char_traits<CHAR>>
MDBX_CXX11_CONSTEXPR ::std::basic_string_view<CHAR, T>
string_view() const noexcept {
static_assert(sizeof(CHAR) == 1, "Must be single byte characters");
return ::std::basic_string_view<CHAR, T>(char_ptr(), length());
}
/// \brief Return a string_view that references the same data as this slice.
template <class CHAR, class T>
MDBX_CXX11_CONSTEXPR explicit
operator ::std::basic_string_view<CHAR, T>() const noexcept {
return this->string_view<CHAR, T>();
}
#endif /* __cpp_lib_string_view >= 201606L */
template <class CHAR = char, class T = ::std::char_traits<CHAR>,
class ALLOCATOR = legacy_allocator>
MDBX_CXX20_CONSTEXPR ::std::basic_string<CHAR, T, ALLOCATOR>
as_string(const ALLOCATOR &allocator = ALLOCATOR()) const {
static_assert(sizeof(CHAR) == 1, "Must be single byte characters");
return ::std::basic_string<CHAR, T, ALLOCATOR>(char_ptr(), length(),
allocator);
}
template <class CHAR, class T, class ALLOCATOR>
MDBX_CXX20_CONSTEXPR explicit
operator ::std::basic_string<CHAR, T, ALLOCATOR>() const {
return as_string<CHAR, T, ALLOCATOR>();
}
/// \brief Returns a string with a hexadecimal dump of the slice content.
template <class ALLOCATOR = legacy_allocator>
inline string<ALLOCATOR>
as_hex_string(bool uppercase = false, unsigned wrap_width = 0,
const ALLOCATOR &allocator = ALLOCATOR()) const;
/// \brief Returns a string with a
/// [Base58](https://en.wikipedia.org/wiki/Base58) dump of the slice content.
template <class ALLOCATOR = legacy_allocator>
inline string<ALLOCATOR>
as_base58_string(unsigned wrap_width = 0,
const ALLOCATOR &allocator = ALLOCATOR()) const;
/// \brief Returns a string with a
/// [Base58](https://en.wikipedia.org/wiki/Base64) dump of the slice content.
template <class ALLOCATOR = legacy_allocator>
inline string<ALLOCATOR>
as_base64_string(unsigned wrap_width = 0,
const ALLOCATOR &allocator = ALLOCATOR()) const;
/// \brief Returns a buffer with a hexadecimal dump of the slice content.
template <class ALLOCATOR = legacy_allocator,
class CAPACITY_POLICY = default_capacity_policy>
inline buffer<ALLOCATOR, CAPACITY_POLICY>
encode_hex(bool uppercase = false, unsigned wrap_width = 0,
const ALLOCATOR &allocator = ALLOCATOR()) const;
/// \brief Returns a buffer with a
/// [Base58](https://en.wikipedia.org/wiki/Base58) dump of the slice content.
template <class ALLOCATOR = legacy_allocator,
class CAPACITY_POLICY = default_capacity_policy>
inline buffer<ALLOCATOR, CAPACITY_POLICY>
encode_base58(unsigned wrap_width = 0,
const ALLOCATOR &allocator = ALLOCATOR()) const;
/// \brief Returns a buffer with a
/// [Base64](https://en.wikipedia.org/wiki/Base64) dump of the slice content.
template <class ALLOCATOR = legacy_allocator,
class CAPACITY_POLICY = default_capacity_policy>
inline buffer<ALLOCATOR, CAPACITY_POLICY>
encode_base64(unsigned wrap_width = 0,
const ALLOCATOR &allocator = ALLOCATOR()) const;
/// \brief Decodes hexadecimal dump from the slice content to returned buffer.
template <class ALLOCATOR = legacy_allocator,
class CAPACITY_POLICY = default_capacity_policy>
inline buffer<ALLOCATOR, CAPACITY_POLICY>
hex_decode(bool ignore_spaces = false,
const ALLOCATOR &allocator = ALLOCATOR()) const;
/// \brief Decodes [Base58](https://en.wikipedia.org/wiki/Base58) dump
/// from the slice content to returned buffer.
template <class ALLOCATOR = legacy_allocator,
class CAPACITY_POLICY = default_capacity_policy>
inline buffer<ALLOCATOR, CAPACITY_POLICY>
base58_decode(bool ignore_spaces = false,
const ALLOCATOR &allocator = ALLOCATOR()) const;
/// \brief Decodes [Base64](https://en.wikipedia.org/wiki/Base64) dump
/// from the slice content to returned buffer.
template <class ALLOCATOR = legacy_allocator,
class CAPACITY_POLICY = default_capacity_policy>
inline buffer<ALLOCATOR, CAPACITY_POLICY>
base64_decode(bool ignore_spaces = false,
const ALLOCATOR &allocator = ALLOCATOR()) const;
/// \brief Checks whether the content of the slice is printable.
/// \param [in] disable_utf8 By default if `disable_utf8` is `false` function
/// checks that content bytes are printable ASCII-7 characters or a valid UTF8
/// sequences. Otherwise, if if `disable_utf8` is `true` function checks that
/// content bytes are printable extended 8-bit ASCII codes.
MDBX_NOTHROW_PURE_FUNCTION bool
is_printable(bool disable_utf8 = false) const noexcept;
/// \brief Checks whether the content of the slice is a hexadecimal dump.
/// \param [in] ignore_spaces If `true` function will skips spaces surrounding
/// (before, between and after) a encoded bytes. However, spaces should not
/// break a pair of characters encoding a single byte.
inline MDBX_NOTHROW_PURE_FUNCTION bool
is_hex(bool ignore_spaces = false) const noexcept;
/// \brief Checks whether the content of the slice is a
/// [Base58](https://en.wikipedia.org/wiki/Base58) dump.
/// \param [in] ignore_spaces If `true` function will skips spaces surrounding
/// (before, between and after) a encoded bytes. However, spaces should not
/// break a code group of characters.
inline MDBX_NOTHROW_PURE_FUNCTION bool
is_base58(bool ignore_spaces = false) const noexcept;
/// \brief Checks whether the content of the slice is a
/// [Base64](https://en.wikipedia.org/wiki/Base64) dump.
/// \param [in] ignore_spaces If `true` function will skips spaces surrounding
/// (before, between and after) a encoded bytes. However, spaces should not
/// break a code group of characters.
inline MDBX_NOTHROW_PURE_FUNCTION bool
is_base64(bool ignore_spaces = false) const noexcept;
inline void swap(slice &other) noexcept;
#if defined(DOXYGEN) || \
(defined(__cpp_lib_string_view) && __cpp_lib_string_view >= 201606L)
template <class CHAR, class T>
void swap(::std::basic_string_view<CHAR, T> &view) noexcept {
static_assert(sizeof(CHAR) == 1, "Must be single byte characters");
const auto temp = ::std::basic_string_view<CHAR, T>(*this);
*this = view;
view = temp;
}
#endif /* __cpp_lib_string_view >= 201606L */
/// \brief Returns casted to pointer to byte an address of data.
MDBX_CXX11_CONSTEXPR const byte *byte_ptr() const noexcept;
MDBX_CXX11_CONSTEXPR byte *byte_ptr() noexcept;
/// \brief Returns casted to pointer to byte an end of data.
MDBX_CXX11_CONSTEXPR const byte *end_byte_ptr() const noexcept;
MDBX_CXX11_CONSTEXPR byte *end_byte_ptr() noexcept;
/// \brief Returns casted to pointer to char an address of data.
MDBX_CXX11_CONSTEXPR const char *char_ptr() const noexcept;
MDBX_CXX11_CONSTEXPR char *char_ptr() noexcept;
/// \brief Returns casted to pointer to char an end of data.
MDBX_CXX11_CONSTEXPR const char *end_char_ptr() const noexcept;
MDBX_CXX11_CONSTEXPR char *end_char_ptr() noexcept;
/// \brief Return a pointer to the beginning of the referenced data.
MDBX_CXX11_CONSTEXPR const void *data() const noexcept;
MDBX_CXX11_CONSTEXPR void *data() noexcept;
/// \brief Return a pointer to the ending of the referenced data.
MDBX_CXX11_CONSTEXPR const void *end() const noexcept;
MDBX_CXX11_CONSTEXPR void *end() noexcept;
/// \brief Returns the number of bytes.
MDBX_CXX11_CONSTEXPR size_t length() const noexcept;
/// \brief Set slice length.
MDBX_CXX14_CONSTEXPR slice &set_length(size_t bytes);
/// \brief Sets the length by specifying the end of the slice data.
MDBX_CXX14_CONSTEXPR slice &set_end(const void *ptr);
/// \brief Checks whether the slice is empty.
MDBX_CXX11_CONSTEXPR bool empty() const noexcept;
/// \brief Checks whether the slice data pointer is nullptr.
MDBX_CXX11_CONSTEXPR bool is_null() const noexcept;
/// \brief Returns the number of bytes.
MDBX_CXX11_CONSTEXPR size_t size() const noexcept;
/// \brief Returns true if slice is not empty.
MDBX_CXX11_CONSTEXPR operator bool() const noexcept;
/// \brief Depletes content of slice and make it invalid.
MDBX_CXX14_CONSTEXPR void invalidate() noexcept;
/// \brief Makes the slice empty and referencing to nothing.
MDBX_CXX14_CONSTEXPR void clear() noexcept;
/// \brief Drops the first "n" bytes from this slice.
/// \pre REQUIRES: `n <= size()`
inline void remove_prefix(size_t n) noexcept;
/// \brief Drops the last "n" bytes from this slice.
/// \pre REQUIRES: `n <= size()`
inline void remove_suffix(size_t n) noexcept;
/// \brief Drops the first "n" bytes from this slice.
/// \throws std::out_of_range if `n > size()`
inline void safe_remove_prefix(size_t n);
/// \brief Drops the last "n" bytes from this slice.
/// \throws std::out_of_range if `n > size()`
inline void safe_remove_suffix(size_t n);
/// \brief Checks if the data starts with the given prefix.
MDBX_NOTHROW_PURE_FUNCTION MDBX_CXX14_CONSTEXPR bool
starts_with(const slice &prefix) const noexcept;
/// \brief Checks if the data ends with the given suffix.
MDBX_NOTHROW_PURE_FUNCTION MDBX_CXX14_CONSTEXPR bool
ends_with(const slice &suffix) const noexcept;
/// \brief Returns the nth byte in the referenced data.
/// \pre REQUIRES: `n < size()`
MDBX_CXX11_CONSTEXPR byte operator[](size_t n) const noexcept;
/// \brief Returns the nth byte in the referenced data with bounds checking.
/// \throws std::out_of_range if `n >= size()`
MDBX_CXX11_CONSTEXPR byte at(size_t n) const;
/// \brief Returns the first "n" bytes of the slice.
/// \pre REQUIRES: `n <= size()`
MDBX_CXX14_CONSTEXPR slice head(size_t n) const noexcept;
/// \brief Returns the last "n" bytes of the slice.
/// \pre REQUIRES: `n <= size()`
MDBX_CXX14_CONSTEXPR slice tail(size_t n) const noexcept;
/// \brief Returns the middle "n" bytes of the slice.
/// \pre REQUIRES: `from + n <= size()`
MDBX_CXX14_CONSTEXPR slice middle(size_t from, size_t n) const noexcept;
/// \brief Returns the first "n" bytes of the slice.
/// \throws std::out_of_range if `n >= size()`
MDBX_CXX14_CONSTEXPR slice safe_head(size_t n) const;
/// \brief Returns the last "n" bytes of the slice.
/// \throws std::out_of_range if `n >= size()`
MDBX_CXX14_CONSTEXPR slice safe_tail(size_t n) const;
/// \brief Returns the middle "n" bytes of the slice.
/// \throws std::out_of_range if `from + n >= size()`
MDBX_CXX14_CONSTEXPR slice safe_middle(size_t from, size_t n) const;
/// \brief Returns the hash value of referenced data.
/// \attention Function implementation and returned hash values may changed
/// version to version, and in future the t1ha3 will be used here. Therefore
/// values obtained from this function shouldn't be persisted anywhere.
MDBX_NOTHROW_PURE_FUNCTION MDBX_CXX14_CONSTEXPR size_t
hash_value() const noexcept;
/// \brief Three-way fast non-lexicographically length-based comparison.
/// \return value:
/// == 0 if "a" == "b",
/// < 0 if "a" shorter than "b",
/// > 0 if "a" longer than "b",
/// < 0 if "a" length-equal and lexicographically less than "b",
/// > 0 if "a" length-equal and lexicographically great than "b".
MDBX_NOTHROW_PURE_FUNCTION static MDBX_CXX14_CONSTEXPR intptr_t
compare_fast(const slice &a, const slice &b) noexcept;
/// \brief Three-way lexicographically comparison.
/// \return value:
/// < 0 if "a" < "b",
/// == 0 if "a" == "b",
/// > 0 if "a" > "b".
MDBX_NOTHROW_PURE_FUNCTION static MDBX_CXX14_CONSTEXPR intptr_t
compare_lexicographically(const slice &a, const slice &b) noexcept;
friend MDBX_CXX14_CONSTEXPR bool operator==(const slice &a,
const slice &b) noexcept;
friend MDBX_CXX14_CONSTEXPR bool operator<(const slice &a,
const slice &b) noexcept;
friend MDBX_CXX14_CONSTEXPR bool operator>(const slice &a,
const slice &b) noexcept;
friend MDBX_CXX14_CONSTEXPR bool operator<=(const slice &a,
const slice &b) noexcept;
friend MDBX_CXX14_CONSTEXPR bool operator>=(const slice &a,
const slice &b) noexcept;
friend MDBX_CXX14_CONSTEXPR bool operator!=(const slice &a,
const slice &b) noexcept;
/// \brief Checks the slice is not refers to null address or has zero length.
MDBX_CXX11_CONSTEXPR bool is_valid() const noexcept {
return !(iov_base == nullptr && iov_len != 0);
}
/// \brief Build an invalid slice which non-zero length and refers to null
/// address.
MDBX_CXX14_CONSTEXPR static slice invalid() noexcept {
return slice(size_t(-1));
}
protected:
MDBX_CXX11_CONSTEXPR slice(size_t invalid_length) noexcept
: ::MDBX_val({nullptr, invalid_length}) {}
};
//------------------------------------------------------------------------------
namespace allocation_aware_details {
template <typename A> constexpr bool allocator_is_always_equal() noexcept {
#if defined(__cpp_lib_allocator_traits_is_always_equal) && \
__cpp_lib_allocator_traits_is_always_equal >= 201411L
return ::std::allocator_traits<A>::is_always_equal::value;
#else
return ::std::is_empty<A>::value;
#endif /* __cpp_lib_allocator_traits_is_always_equal */
}
template <typename T, typename A = typename T::allocator_type,
bool PoCMA = ::std::allocator_traits<
A>::propagate_on_container_move_assignment::value>
struct move_assign_alloc;
template <typename T, typename A> struct move_assign_alloc<T, A, false> {
static constexpr bool is_nothrow() noexcept {
return allocator_is_always_equal<A>();
}
static MDBX_CXX20_CONSTEXPR bool is_moveable(T *target, T &source) noexcept {
return allocator_is_always_equal<A>() ||
target->get_allocator() == source.get_allocator();
}
static MDBX_CXX20_CONSTEXPR void propagate(T *target, T &source) noexcept {
assert(target->get_allocator() != source.get_allocator());
(void)target;
(void)source;
}
};