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mdbx.h
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mdbx.h
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/**
_libmdbx_ is an extremely fast, compact, powerful, embedded,
transactional [key-value
store](https://en.wikipedia.org/wiki/Key-value_database) database, with
[permissive license](./LICENSE). _MDBX_ has a specific set of properties and
capabilities, focused on creating unique lightweight solutions with
extraordinary performance.
_libmdbx_ is superior to [LMDB](https://bit.ly/26ts7tL) in terms of features
and reliability, not inferior in performance. In comparison to LMDB, _libmdbx_
makes many things just work perfectly, not silently and catastrophically
break down. _libmdbx_ supports Linux, Windows, MacOS, OSX, iOS, Android,
FreeBSD, DragonFly, Solaris, OpenSolaris, OpenIndiana, NetBSD, OpenBSD and other
systems compliant with POSIX.1-2008.
_The Future will (be) [Positive](https://www.ptsecurity.com). Всё будет хорошо._
\section copyright LICENSE & COPYRIGHT
\authors Copyright (c) 2015-2021, Leonid Yuriev <leo@yuriev.ru>
and other _libmdbx_ authors: please see [AUTHORS](./AUTHORS) file.
\copyright Redistribution and use in source and binary forms, with or without
modification, are permitted only as authorized by the OpenLDAP Public License.
A copy of this license is available in the file LICENSE in the
top-level directory of the distribution or, alternatively, at
<http://www.OpenLDAP.org/license.html>.
---
This code is derived from "LMDB engine" written by
Howard Chu (Symas Corporation), which itself derived from btree.c
written by Martin Hedenfalk.
---
Portions Copyright 2011-2015 Howard Chu, Symas Corp. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted only as authorized by the OpenLDAP
Public License.
A copy of this license is available in the file LICENSE in the
top-level directory of the distribution or, alternatively, at
<http://www.OpenLDAP.org/license.html>.
---
Portions Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*******************************************************************************/
#pragma once
#ifndef LIBMDBX_H
#define LIBMDBX_H
#ifdef _MSC_VER
#pragma warning(push, 1)
#pragma warning(disable : 4548) /* expression before comma has no effect; \
expected expression with side - effect */
#pragma warning(disable : 4530) /* C++ exception handler used, but unwind \
* semantics are not enabled. Specify /EHsc */
#pragma warning(disable : 4577) /* 'noexcept' used with no exception handling \
* mode specified; termination on exception is \
* not guaranteed. Specify /EHsc */
#endif /* _MSC_VER (warnings) */
/* *INDENT-OFF* */
/* clang-format off */
/**
\file mdbx.h
\brief The libmdbx C API header file
\defgroup c_api C API
@{
\defgroup c_err Error handling
\defgroup c_opening Opening & Closing
\defgroup c_transactions Transactions
\defgroup c_dbi Databases
\defgroup c_crud Create/Read/Update/Delete (see Quick Reference in details)
\details
\anchor c_crud_hints
# Quick Reference for Insert/Update/Delete operations
Historically, libmdbx inherits the API basis from LMDB, where it is often
difficult to select flags/options and functions for the desired operation.
So it is recommend using this hints.
## Databases with UNIQUE keys
In databases created without the \ref MDBX_DUPSORT option, keys are always
unique. Thus always a single value corresponds to the each key, and so there
are only a few cases of changing data.
| Case | Flags to use | Result |
|---------------------------------------------|---------------------|------------------------|
| _INSERTING_|||
|Key is absent → Insertion |\ref MDBX_NOOVERWRITE|Insertion |
|Key exist → Error since key present |\ref MDBX_NOOVERWRITE|Error \ref MDBX_KEYEXIST and return Present value|
| _UPSERTING_|||
|Key is absent → Insertion |\ref MDBX_UPSERT |Insertion |
|Key exist → Update |\ref MDBX_UPSERT |Update |
| _UPDATING_|||
|Key is absent → Error since no such key |\ref MDBX_CURRENT |Error \ref MDBX_NOTFOUND|
|Key exist → Update |\ref MDBX_CURRENT |Update value |
| _DELETING_|||
|Key is absent → Error since no such key |\ref mdbx_del() or \ref mdbx_replace()|Error \ref MDBX_NOTFOUND|
|Key exist → Delete by key |\ref mdbx_del() with the parameter `data = NULL`|Deletion|
|Key exist → Delete by key with with data matching check|\ref mdbx_del() with the parameter `data` filled with the value which should be match for deletion|Deletion or \ref MDBX_NOTFOUND if the value does not match|
|Delete at the current cursor position |\ref mdbx_cursor_del() with \ref MDBX_CURRENT flag|Deletion|
|Extract (read & delete) value by the key |\ref mdbx_replace() with zero flag and parameter `new_data = NULL`|Returning a deleted value|
## Databases with NON-UNIQUE keys
In databases created with the \ref MDBX_DUPSORT (Sorted Duplicates) option, keys
may be non unique. Such non-unique keys in a key-value database may be treated
as a duplicates or as like a multiple values corresponds to keys.
| Case | Flags to use | Result |
|---------------------------------------------|---------------------|------------------------|
| _INSERTING_|||
|Key is absent → Insertion |\ref MDBX_NOOVERWRITE|Insertion|
|Key exist → Needn't to add new values |\ref MDBX_NOOVERWRITE|Error \ref MDBX_KEYEXIST with returning the first value from those already present|
| _UPSERTING_|||
|Key is absent → Insertion |\ref MDBX_UPSERT |Insertion|
|Key exist → Wanna to add new values |\ref MDBX_UPSERT |Add one more value to the key|
|Key exist → Replace all values with a new one|\ref MDBX_UPSERT + \ref MDBX_ALLDUPS|Overwrite by single new value|
| _UPDATING_|||
|Key is absent → Error since no such key |\ref MDBX_CURRENT |Error \ref MDBX_NOTFOUND|
|Key exist, Single value → Update |\ref MDBX_CURRENT |Update single value |
|Key exist, Multiple values → Replace all values with a new one|\ref MDBX_CURRENT + \ref MDBX_ALLDUPS|Overwrite by single new value|
|Key exist, Multiple values → Error since it is unclear which of the values should be updated|\ref mdbx_put() with \ref MDBX_CURRENT|Error \ref MDBX_EMULTIVAL|
|Key exist, Multiple values → Update particular entry of multi-value|\ref mdbx_replace() with \ref MDBX_CURRENT + \ref MDBX_NOOVERWRITE and the parameter `old_value` filled with the value that wanna to update|Update one multi-value entry|
|Key exist, Multiple values → Update the current entry of multi-value|\ref mdbx_cursor_put() with \ref MDBX_CURRENT|Update one multi-value entry|
| _DELETING_|||
|Key is absent → Error since no such key |\ref mdbx_del() or \ref mdbx_replace()|Error \ref MDBX_NOTFOUND|
|Key exist → Delete all values corresponds given key|\ref mdbx_del() with the parameter `data = NULL`|Deletion|
|Key exist → Delete particular value corresponds given key|\ref mdbx_del() with the parameter `data` filled with the value that wanna to delete, or \ref mdbx_replace() with \ref MDBX_CURRENT + \ref MDBX_NOOVERWRITE and the `old_value` parameter filled with the value that wanna to delete and `new_data = NULL`| Deletion or \ref MDBX_NOTFOUND if no such key-value pair|
|Delete one value at the current cursor position|\ref mdbx_cursor_del() with \ref MDBX_CURRENT flag|Deletion only the current entry|
|Delete all values of key at the current cursor position|\ref mdbx_cursor_del() with with \ref MDBX_ALLDUPS flag|Deletion all duplicates of key (all multi-values) at the current cursor position|
\defgroup c_cursors Cursors
\defgroup c_statinfo Statistics & Information
\defgroup c_settings Settings
\defgroup c_debug Logging and runtime debug
\defgroup c_rqest Range query estimation
\defgroup c_extra Extra operations
*/
/* *INDENT-ON* */
/* clang-format on */
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#if defined(_WIN32) || defined(_WIN64)
#include <windows.h>
#include <winnt.h>
#ifndef __mode_t_defined
typedef unsigned short mdbx_mode_t;
#else
typedef mode_t mdbx_mode_t;
#endif /* __mode_t_defined */
typedef HANDLE mdbx_filehandle_t;
typedef DWORD mdbx_pid_t;
typedef DWORD mdbx_tid_t;
#else /* Windows */
#include <errno.h> /* for error codes */
#include <pthread.h> /* for pthread_t */
#include <sys/types.h> /* for pid_t */
#include <sys/uio.h> /* for struct iovec */
#define HAVE_STRUCT_IOVEC 1
typedef int mdbx_filehandle_t;
typedef pid_t mdbx_pid_t;
typedef pthread_t mdbx_tid_t;
typedef mode_t mdbx_mode_t;
#endif /* !Windows */
#ifdef _MSC_VER
#pragma warning(pop)
#endif
/** @} close c_api
* \defgroup api_macros Common Macros
* @{ */
/*----------------------------------------------------------------------------*/
#ifndef __has_attribute
#define __has_attribute(x) (0)
#endif /* __has_attribute */
#ifndef __has_cpp_attribute
#define __has_cpp_attribute(x) 0
#endif /* __has_cpp_attribute */
#ifndef __has_feature
#define __has_feature(x) (0)
#endif /* __has_feature */
#ifndef __has_extension
#define __has_extension(x) (0)
#endif /* __has_extension */
#ifndef __has_builtin
#define __has_builtin(x) (0)
#endif /* __has_builtin */
/** Many functions have no effects except the return value and their
* return value depends only on the parameters and/or global variables.
* Such a function can be subject to common subexpression elimination
* and loop optimization just as an arithmetic operator would be.
* These functions should be declared with the attribute pure. */
#if (defined(__GNUC__) || __has_attribute(__pure__)) && \
(!defined(__clang__) /* https://bugs.llvm.org/show_bug.cgi?id=43275 */ \
|| !defined(__cplusplus) || !__has_feature(cxx_exceptions))
#define MDBX_PURE_FUNCTION __attribute__((__pure__))
#elif defined(_MSC_VER) && !defined(__clang__) && _MSC_VER >= 1920
#define MDBX_PURE_FUNCTION
#elif defined(__cplusplus) && __has_cpp_attribute(gnu::pure) && \
(!defined(__clang__) || !__has_feature(cxx_exceptions))
#define MDBX_PURE_FUNCTION [[gnu::pure]]
#else
#define MDBX_PURE_FUNCTION
#endif /* MDBX_PURE_FUNCTION */
/** Like \ref MDBX_PURE_FUNCTION with addition `noexcept` restriction
* that is compatible to CLANG and proposed [[pure]]. */
#if defined(__GNUC__) || \
(__has_attribute(__pure__) && __has_attribute(__nothrow__))
#define MDBX_NOTHROW_PURE_FUNCTION __attribute__((__pure__, __nothrow__))
#elif defined(_MSC_VER) && !defined(__clang__) && _MSC_VER >= 1920
#if __has_cpp_attribute(pure)
#define MDBX_NOTHROW_PURE_FUNCTION [[pure]]
#else
#define MDBX_NOTHROW_PURE_FUNCTION
#endif
#elif defined(__cplusplus) && __has_cpp_attribute(gnu::pure)
#if __has_cpp_attribute(gnu::nothrow)
#define MDBX_NOTHROW_PURE_FUNCTION [[gnu::pure, gnu::nothrow]]
#else
#define MDBX_NOTHROW_PURE_FUNCTION [[gnu::pure]]
#endif
#elif defined(__cplusplus) && __has_cpp_attribute(pure)
#define MDBX_NOTHROW_PURE_FUNCTION [[pure]]
#else
#define MDBX_NOTHROW_PURE_FUNCTION
#endif /* MDBX_NOTHROW_PURE_FUNCTION */
/** Many functions do not examine any values except their arguments,
* and have no effects except the return value. Basically this is just
* slightly more strict class than the PURE attribute, since function
* is not allowed to read global memory.
*
* Note that a function that has pointer arguments and examines the
* data pointed to must not be declared const. Likewise, a function
* that calls a non-const function usually must not be const.
* It does not make sense for a const function to return void. */
#if (defined(__GNUC__) || __has_attribute(__pure__)) && \
(!defined(__clang__) /* https://bugs.llvm.org/show_bug.cgi?id=43275 */ \
|| !defined(__cplusplus) || !__has_feature(cxx_exceptions))
#define MDBX_CONST_FUNCTION __attribute__((__const__))
#elif defined(_MSC_VER) && !defined(__clang__) && _MSC_VER >= 1920
#define MDBX_CONST_FUNCTION MDBX_PURE_FUNCTION
#elif defined(__cplusplus) && __has_cpp_attribute(gnu::const) && \
(!defined(__clang__) || !__has_feature(cxx_exceptions))
#define MDBX_CONST_FUNCTION [[gnu::const]]
#else
#define MDBX_CONST_FUNCTION MDBX_PURE_FUNCTION
#endif /* MDBX_CONST_FUNCTION */
/** Like \ref MDBX_CONST_FUNCTION with addition `noexcept` restriction
* that is compatible to CLANG and future [[const]]. */
#if defined(__GNUC__) || \
(__has_attribute(__const__) && __has_attribute(__nothrow__))
#define MDBX_NOTHROW_CONST_FUNCTION __attribute__((__const__, __nothrow__))
#elif defined(_MSC_VER) && !defined(__clang__) && _MSC_VER >= 1920
#define MDBX_NOTHROW_CONST_FUNCTION MDBX_NOTHROW_PURE_FUNCTION
#elif defined(__cplusplus) && __has_cpp_attribute(gnu::const)
#if __has_cpp_attribute(gnu::nothrow)
#define MDBX_NOTHROW_PURE_FUNCTION [[gnu::const, gnu::nothrow]]
#else
#define MDBX_NOTHROW_PURE_FUNCTION [[gnu::const]]
#endif
#elif defined(__cplusplus) && __has_cpp_attribute(const)
#define MDBX_NOTHROW_CONST_FUNCTION [[const]]
#else
#define MDBX_NOTHROW_CONST_FUNCTION MDBX_NOTHROW_PURE_FUNCTION
#endif /* MDBX_NOTHROW_CONST_FUNCTION */
#ifndef MDBX_DEPRECATED /* may be predefined to avoid warnings "deprecated" */
#ifdef __deprecated
#define MDBX_DEPRECATED __deprecated
#elif defined(__GNUC__) || __has_attribute(__deprecated__)
#define MDBX_DEPRECATED __attribute__((__deprecated__))
#elif defined(_MSC_VER)
#define MDBX_DEPRECATED __declspec(deprecated)
#else
#define MDBX_DEPRECATED
#endif
#endif /* MDBX_DEPRECATED */
#ifndef __dll_export
#if defined(_WIN32) || defined(__CYGWIN__)
#if defined(__GNUC__) || __has_attribute(__dllexport__)
#define __dll_export __attribute__((__dllexport__))
#elif defined(_MSC_VER)
#define __dll_export __declspec(dllexport)
#else
#define __dll_export
#endif
#elif defined(__GNUC__) || __has_attribute(__visibility__)
#define __dll_export __attribute__((__visibility__("default")))
#else
#define __dll_export
#endif
#endif /* __dll_export */
#ifndef __dll_import
#if defined(_WIN32) || defined(__CYGWIN__)
#if defined(__GNUC__) || __has_attribute(__dllimport__)
#define __dll_import __attribute__((__dllimport__))
#elif defined(_MSC_VER)
#define __dll_import __declspec(dllimport)
#else
#define __dll_import
#endif
#else
#define __dll_import
#endif
#endif /* __dll_import */
/** \brief Auxiliary macro for robustly define the both inline version of API
* function and non-inline fallback dll-exported version for applications linked
* with old version of libmdbx, with a strictly ODR-common implementation. */
#if defined(LIBMDBX_INTERNALS) && !defined(LIBMDBX_NO_EXPORTS_LEGACY_API)
#define LIBMDBX_INLINE_API(TYPE, NAME, ARGS) \
/* proto of exported which uses common impl */ LIBMDBX_API TYPE NAME ARGS; \
/* definition of common impl */ static __inline TYPE __inline_##NAME ARGS
#else
#define LIBMDBX_INLINE_API(TYPE, NAME, ARGS) static __inline TYPE NAME ARGS
#endif /* LIBMDBX_INLINE_API */
/*----------------------------------------------------------------------------*/
#ifndef __cplusplus
#ifndef bool
#define bool _Bool
#endif
#ifndef true
#define true (1)
#endif
#ifndef false
#define false (0)
#endif
#endif /* bool without __cplusplus */
#if !defined(DOXYGEN) && (!defined(__cpp_noexcept_function_type) || \
__cpp_noexcept_function_type < 201510L)
#define MDBX_CXX17_NOEXCEPT
#else
#define MDBX_CXX17_NOEXCEPT noexcept
#endif /* MDBX_CXX17_NOEXCEPT */
/* Workaround for old compilers without properly support for constexpr. */
#if !defined(__cplusplus)
#define MDBX_CXX01_CONSTEXPR __inline
#define MDBX_CXX01_CONSTEXPR_VAR const
#elif !defined(DOXYGEN) && \
(!defined(__cpp_constexpr) || __cpp_constexpr < 200704L || \
(defined(__LCC__) && __LCC__ < 124) || \
(defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 407) && \
!defined(__clang__) && !defined(__LCC__)) || \
(defined(_MSC_VER) && _MSC_VER < 1910) || \
(defined(__clang__) && __clang_major__ < 4))
#define MDBX_CXX01_CONSTEXPR inline
#define MDBX_CXX01_CONSTEXPR_VAR const
#else
#define MDBX_CXX01_CONSTEXPR constexpr
#define MDBX_CXX01_CONSTEXPR_VAR constexpr
#endif /* MDBX_CXX01_CONSTEXPR */
#if !defined(__cplusplus)
#define MDBX_CXX11_CONSTEXPR __inline
#define MDBX_CXX11_CONSTEXPR_VAR const
#elif !defined(DOXYGEN) && \
(!defined(__cpp_constexpr) || __cpp_constexpr < 201304 || \
(defined(__LCC__) && __LCC__ < 124) || \
(defined(__GNUC__) && __GNUC__ < 6 && !defined(__clang__) && \
!defined(__LCC__)) || \
(defined(_MSC_VER) && _MSC_VER < 1910) || \
(defined(__clang__) && __clang_major__ < 5))
#define MDBX_CXX11_CONSTEXPR inline
#define MDBX_CXX11_CONSTEXPR_VAR const
#else
#define MDBX_CXX11_CONSTEXPR constexpr
#define MDBX_CXX11_CONSTEXPR_VAR constexpr
#endif /* MDBX_CXX11_CONSTEXPR */
#if !defined(__cplusplus)
#define MDBX_CXX14_CONSTEXPR __inline
#define MDBX_CXX14_CONSTEXPR_VAR const
#elif defined(DOXYGEN) || \
defined(__cpp_constexpr) && __cpp_constexpr >= 201304L && \
((defined(_MSC_VER) && _MSC_VER >= 1910) || \
(defined(__clang__) && __clang_major__ > 4) || \
(defined(__GNUC__) && __GNUC__ > 6) || \
(!defined(__GNUC__) && !defined(__clang__) && !defined(_MSC_VER)))
#define MDBX_CXX14_CONSTEXPR constexpr
#define MDBX_CXX14_CONSTEXPR_VAR constexpr
#else
#define MDBX_CXX14_CONSTEXPR inline
#define MDBX_CXX14_CONSTEXPR_VAR const
#endif /* MDBX_CXX14_CONSTEXPR */
#if defined(__noreturn)
#define MDBX_NORETURN __noreturn
#elif defined(_Noreturn)
#define MDBX_NORETURN _Noreturn
#elif defined(__GNUC__) || __has_attribute(__noreturn__)
#define MDBX_NORETURN __attribute__((__noreturn__))
#elif defined(_MSC_VER) && !defined(__clang__)
#define MDBX_NORETURN __declspec(noreturn)
#else
#define MDBX_NORETURN
#endif /* MDBX_NORETURN */
#ifndef MDBX_PRINTF_ARGS
#if defined(__GNUC__) || __has_attribute(__format__)
#define MDBX_PRINTF_ARGS(format_index, first_arg) \
__attribute__((__format__(__printf__, format_index, first_arg)))
#else
#define MDBX_PRINTF_ARGS(format_index, first_arg)
#endif
#endif /* MDBX_PRINTF_ARGS */
/* Oh, below are some songs and dances since:
* - C++ requires explicit definition of the necessary operators.
* - the proper implementation of DEFINE_ENUM_FLAG_OPERATORS for C++ required
* the constexpr feature which is broken in most old compilers;
* - DEFINE_ENUM_FLAG_OPERATORS may be defined broken as in the Windows SDK. */
#ifndef DEFINE_ENUM_FLAG_OPERATORS
#ifdef __cplusplus
#if !defined(__cpp_constexpr) || __cpp_constexpr < 200704L || \
(defined(__LCC__) && __LCC__ < 124) || \
(defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 407) && \
!defined(__clang__) && !defined(__LCC__)) || \
(defined(_MSC_VER) && _MSC_VER < 1910) || \
(defined(__clang__) && __clang_major__ < 4)
/* The constexpr feature is not available or (may be) broken */
#define CONSTEXPR_ENUM_FLAGS_OPERATIONS 0
#else
/* C always allows these operators for enums */
#define CONSTEXPR_ENUM_FLAGS_OPERATIONS 1
#endif /* __cpp_constexpr */
/// Define operator overloads to enable bit operations on enum values that are
/// used to define flags (based on Microsoft's DEFINE_ENUM_FLAG_OPERATORS).
#define DEFINE_ENUM_FLAG_OPERATORS(ENUM) \
extern "C++" { \
MDBX_CXX01_CONSTEXPR ENUM operator|(ENUM a, ENUM b) { \
return ENUM(unsigned(a) | unsigned(b)); \
} \
MDBX_CXX14_CONSTEXPR ENUM &operator|=(ENUM &a, ENUM b) { return a = a | b; } \
MDBX_CXX01_CONSTEXPR ENUM operator&(ENUM a, ENUM b) { \
return ENUM(unsigned(a) & unsigned(b)); \
} \
MDBX_CXX01_CONSTEXPR ENUM operator&(ENUM a, unsigned b) { \
return ENUM(unsigned(a) & b); \
} \
MDBX_CXX01_CONSTEXPR ENUM operator&(unsigned a, ENUM b) { \
return ENUM(a & unsigned(b)); \
} \
MDBX_CXX14_CONSTEXPR ENUM &operator&=(ENUM &a, ENUM b) { return a = a & b; } \
MDBX_CXX14_CONSTEXPR ENUM &operator&=(ENUM &a, unsigned b) { \
return a = a & b; \
} \
MDBX_CXX01_CONSTEXPR unsigned operator~(ENUM a) { return ~unsigned(a); } \
MDBX_CXX01_CONSTEXPR ENUM operator^(ENUM a, ENUM b) { \
return ENUM(unsigned(a) ^ unsigned(b)); \
} \
MDBX_CXX14_CONSTEXPR ENUM &operator^=(ENUM &a, ENUM b) { return a = a ^ b; } \
}
#else /* __cplusplus */
/* nope for C since it always allows these operators for enums */
#define DEFINE_ENUM_FLAG_OPERATORS(ENUM)
#define CONSTEXPR_ENUM_FLAGS_OPERATIONS 1
#endif /* !__cplusplus */
#elif !defined(CONSTEXPR_ENUM_FLAGS_OPERATIONS)
#ifdef __cplusplus
/* DEFINE_ENUM_FLAG_OPERATORS may be defined broken as in the Windows SDK */
#define CONSTEXPR_ENUM_FLAGS_OPERATIONS 0
#else
/* C always allows these operators for enums */
#define CONSTEXPR_ENUM_FLAGS_OPERATIONS 1
#endif
#endif /* DEFINE_ENUM_FLAG_OPERATORS */
/** @} end of Common Macros */
/*----------------------------------------------------------------------------*/
/** \addtogroup c_api
* @{ */
#ifdef __cplusplus
extern "C" {
#endif
/* MDBX version 0.10.x */
#define MDBX_VERSION_MAJOR 0
#define MDBX_VERSION_MINOR 10
#ifndef LIBMDBX_API
#if defined(LIBMDBX_EXPORTS)
#define LIBMDBX_API __dll_export
#elif defined(LIBMDBX_IMPORTS)
#define LIBMDBX_API __dll_import
#else
#define LIBMDBX_API
#endif
#endif /* LIBMDBX_API */
#ifdef __cplusplus
#if defined(__clang__) || __has_attribute(type_visibility)
#define LIBMDBX_API_TYPE LIBMDBX_API __attribute__((type_visibility("default")))
#else
#define LIBMDBX_API_TYPE LIBMDBX_API
#endif
#else
#define LIBMDBX_API_TYPE
#endif /* LIBMDBX_API_TYPE */
#if defined(LIBMDBX_IMPORTS)
#define LIBMDBX_VERINFO_API __dll_import
#else
#define LIBMDBX_VERINFO_API __dll_export
#endif /* LIBMDBX_VERINFO_API */
/** \brief libmdbx version information */
extern LIBMDBX_VERINFO_API const struct MDBX_version_info {
uint8_t major; /**< Major version number */
uint8_t minor; /**< Minor version number */
uint16_t release; /**< Release number of Major.Minor */
uint32_t revision; /**< Revision number of Release */
struct {
const char *datetime; /**< committer date, strict ISO-8601 format */
const char *tree; /**< commit hash (hexadecimal digits) */
const char *commit; /**< tree hash, i.e. digest of the source code */
const char *describe; /**< git-describe string */
} git; /**< source information from git */
const char *sourcery; /**< sourcery anchor for pinning */
} /** \brief libmdbx version information */ mdbx_version;
/** \brief libmdbx build information
* \attention Some strings could be NULL in case no corresponding information
* was provided at build time (i.e. flags). */
extern LIBMDBX_VERINFO_API const struct MDBX_build_info {
const char *datetime; /**< build timestamp (ISO-8601 or __DATE__ __TIME__) */
const char *target; /**< cpu/arch-system-config triplet */
const char *options; /**< mdbx-related options */
const char *compiler; /**< compiler */
const char *flags; /**< CFLAGS and CXXFLAGS */
} /** \brief libmdbx build information */ mdbx_build;
#if (defined(_WIN32) || defined(_WIN64)) && !MDBX_BUILD_SHARED_LIBRARY
/* MDBX internally uses global and thread local storage destructors to
* automatically (de)initialization, releasing reader lock table slots
* and so on.
*
* If MDBX builded as a DLL this is done out-of-the-box by DllEntry() function,
* which called automatically by Windows core with passing corresponding reason
* argument.
*
* Otherwise, if MDBX was builded not as a DLL, some black magic
* may be required depending of Windows version:
*
* - Modern Windows versions, including Windows Vista and later, provides
* support for "TLS Directory" (e.g .CRT$XL[A-Z] sections in executable
* or dll file). In this case, MDBX capable of doing all automatically,
* therefore you DON'T NEED to call mdbx_module_handler()
* so the MDBX_MANUAL_MODULE_HANDLER defined as 0.
*
* - Obsolete versions of Windows, prior to Windows Vista, REQUIRES calling
* mdbx_module_handler() manually from corresponding DllMain() or WinMain()
* of your DLL or application,
* so the MDBX_MANUAL_MODULE_HANDLER defined as 1.
*
* Therefore, building MDBX as a DLL is recommended for all version of Windows.
* So, if you doubt, just build MDBX as the separate DLL and don't care about
* the MDBX_MANUAL_MODULE_HANDLER. */
#ifndef _WIN32_WINNT
#error Non-dll build libmdbx requires target Windows version \
to be explicitly defined via _WIN32_WINNT for properly \
handling thread local storage destructors.
#endif /* _WIN32_WINNT */
#if _WIN32_WINNT >= 0x0600 /* Windows Vista */
/* As described above mdbx_module_handler() is NOT needed for Windows Vista
* and later. */
#define MDBX_MANUAL_MODULE_HANDLER 0
#else
/* As described above mdbx_module_handler() IS REQUIRED for Windows versions
* prior to Windows Vista. */
#define MDBX_MANUAL_MODULE_HANDLER 1
void LIBMDBX_API NTAPI mdbx_module_handler(PVOID module, DWORD reason,
PVOID reserved);
#endif
#endif /* Windows && !DLL && MDBX_MANUAL_MODULE_HANDLER */
/* OPACITY STRUCTURES *********************************************************/
/** \brief Opaque structure for a database environment.
* \details An environment supports multiple key-value sub-databases (aka
* key-value spaces or tables), all residing in the same shared-memory map.
* \see mdbx_env_create() \see mdbx_env_close() */
#ifndef __cplusplus
typedef struct MDBX_env MDBX_env;
#else
struct MDBX_env;
#endif
/** \brief Opaque structure for a transaction handle.
* \ingroup c_transactions
* \details All database operations require a transaction handle. Transactions
* may be read-only or read-write.
* \see mdbx_txn_begin() \see mdbx_txn_commit() \see mdbx_txn_abort() */
#ifndef __cplusplus
typedef struct MDBX_txn MDBX_txn;
#else
struct MDBX_txn;
#endif
/** \brief A handle for an individual database (key-value spaces) in the
* environment. \ingroup c_dbi \details Zero handle is used internally (hidden
* Garbage Collection DB). So, any valid DBI-handle great than 0 and less than
* or equal \ref MDBX_MAX_DBI. \see mdbx_dbi_open() \see mdbx_dbi_close() */
typedef uint32_t MDBX_dbi;
/** \brief Opaque structure for navigating through a database
* \ingroup c_cursors
* \see mdbx_cursor_create() \see mdbx_cursor_bind() \see mdbx_cursor_close()
*/
#ifndef __cplusplus
typedef struct MDBX_cursor MDBX_cursor;
#else
struct MDBX_cursor;
#endif
/** \brief Generic structure used for passing keys and data in and out of the
* database.
* \anchor MDBX_val \see mdbx::slice \see mdbx::buffer
*
* \details Values returned from the database are valid only until a subsequent
* update operation, or the end of the transaction. Do not modify or
* free them, they commonly point into the database itself.
*
* Key sizes must be between 0 and \ref mdbx_env_get_maxkeysize() inclusive.
* The same applies to data sizes in databases with the \ref MDBX_DUPSORT flag.
* Other data items can in theory be from 0 to \ref MDBX_MAXDATASIZE bytes long.
*
* \note The notable difference between MDBX and LMDB is that MDBX support zero
* length keys. */
#ifndef HAVE_STRUCT_IOVEC
struct iovec {
void *iov_base; /**< pointer to some data */
size_t iov_len; /**< the length of data in bytes */
};
#define HAVE_STRUCT_IOVEC
#endif /* HAVE_STRUCT_IOVEC */
#if defined(__sun) || defined(__SVR4) || defined(__svr4__)
/* The `iov_len` is signed on Sun/Solaris.
* So define custom MDBX_val to avoid a lot of warnings. */
struct MDBX_val {
void *iov_base; /**< pointer to some data */
size_t iov_len; /**< the length of data in bytes */
};
#ifndef __cplusplus
typedef struct MDBX_val MDBX_val;
#endif
#else /* SunOS */
typedef struct iovec MDBX_val;
#endif /* ! SunOS */
enum MDBX_constants {
/** The hard limit for DBI handles */
MDBX_MAX_DBI = UINT32_C(32765),
/** The maximum size of a data item. */
MDBX_MAXDATASIZE = UINT32_C(0x7fff0000),
/** The minimal database page size in bytes. */
MDBX_MIN_PAGESIZE = 256,
/** The maximal database page size in bytes. */
MDBX_MAX_PAGESIZE = 65536,
};
/* THE FILES *******************************************************************
* At the file system level, the environment corresponds to a pair of files. */
/** \brief The name of the lock file in the environment */
#define MDBX_LOCKNAME "/mdbx.lck"
/** \brief The name of the data file in the environment */
#define MDBX_DATANAME "/mdbx.dat"
/** \brief The suffix of the lock file when \ref MDBX_NOSUBDIR is used */
#define MDBX_LOCK_SUFFIX "-lck"
/* DEBUG & LOGGING ************************************************************/
/** \addtogroup c_debug
* \note Most of debug feature enabled only when libmdbx builded with
* \ref MDBX_DEBUG build option. @{ */
/** Log level (requires build libmdbx with \ref MDBX_DEBUG option) */
enum MDBX_log_level_t {
/** Critical conditions, i.e. assertion failures */
MDBX_LOG_FATAL = 0,
/** Enables logging for error conditions and \ref MDBX_LOG_FATAL */
MDBX_LOG_ERROR = 1,
/** Enables logging for warning conditions and \ref MDBX_LOG_ERROR ...
\ref MDBX_LOG_FATAL */
MDBX_LOG_WARN = 2,
/** Enables logging for normal but significant condition and
\ref MDBX_LOG_WARN ... \ref MDBX_LOG_FATAL */
MDBX_LOG_NOTICE = 3,
/** Enables logging for verbose informational and \ref MDBX_LOG_NOTICE ...
\ref MDBX_LOG_FATAL */
MDBX_LOG_VERBOSE = 4,
/** Enables logging for debug-level messages and \ref MDBX_LOG_VERBOSE ...
\ref MDBX_LOG_FATAL */
MDBX_LOG_DEBUG = 5,
/** Enables logging for trace debug-level messages and \ref MDBX_LOG_DEBUG ...
\ref MDBX_LOG_FATAL */
MDBX_LOG_TRACE = 6,
/** Enables extra debug-level messages (dump pgno lists)
and all other log-messages */
MDBX_LOG_EXTRA = 7,
/** for \ref mdbx_setup_debug() only: Don't change current settings */
MDBX_LOG_DONTCHANGE = -1
};
#ifndef __cplusplus
typedef enum MDBX_log_level_t MDBX_log_level_t;
#endif
/** \brief Runtime debug flags
*
* \details `MDBX_DBG_DUMP` and `MDBX_DBG_LEGACY_MULTIOPEN` always have an
* effect, but `MDBX_DBG_ASSERT`, `MDBX_DBG_AUDIT` and `MDBX_DBG_JITTER` only if
* libmdbx builded with \ref MDBX_DEBUG. */
enum MDBX_debug_flags_t {
/** Enable assertion checks.
* Requires build with \ref MDBX_DEBUG > 0 */
MDBX_DBG_ASSERT = 1,
/** Enable pages usage audit at commit transactions.
* Requires build with \ref MDBX_DEBUG > 0 */
MDBX_DBG_AUDIT = 2,
/** Enable small random delays in critical points.
* Requires build with \ref MDBX_DEBUG > 0 */
MDBX_DBG_JITTER = 4,
/** Include or not meta-pages in coredump files.
* May affect performance in \ref MDBX_WRITEMAP mode */
MDBX_DBG_DUMP = 8,
/** Allow multi-opening environment(s) */
MDBX_DBG_LEGACY_MULTIOPEN = 16,
/** Allow read and write transactions overlapping for the same thread */
MDBX_DBG_LEGACY_OVERLAP = 32,
/** for mdbx_setup_debug() only: Don't change current settings */
MDBX_DBG_DONTCHANGE = -1
};
#ifndef __cplusplus
typedef enum MDBX_debug_flags_t MDBX_debug_flags_t;
#else
DEFINE_ENUM_FLAG_OPERATORS(MDBX_debug_flags_t)
#endif
/** \brief A debug-logger callback function,
* called before printing the message and aborting.
* \see mdbx_setup_debug()
*
* \param [in] env An environment handle returned by \ref mdbx_env_create().
* \param [in] msg The assertion message, not including newline. */
typedef void MDBX_debug_func(MDBX_log_level_t loglevel, const char *function,
int line, const char *fmt,
va_list args) MDBX_CXX17_NOEXCEPT;
/** \brief The "don't change `logger`" value for mdbx_setup_debug() */
#define MDBX_LOGGER_DONTCHANGE ((MDBX_debug_func *)(intptr_t)-1)
/** \brief Setup global log-level, debug options and debug logger.
* \returns The previously `debug_flags` in the 0-15 bits
* and `log_level` in the 16-31 bits. */
LIBMDBX_API int mdbx_setup_debug(MDBX_log_level_t log_level,
MDBX_debug_flags_t debug_flags,
MDBX_debug_func *logger);
/** \brief A callback function for most MDBX assert() failures,
* called before printing the message and aborting.
* \see mdbx_env_set_assert()
*
* \param [in] env An environment handle returned by mdbx_env_create().
* \param [in] msg The assertion message, not including newline. */
typedef void MDBX_assert_func(const MDBX_env *env, const char *msg,
const char *function,
unsigned line) MDBX_CXX17_NOEXCEPT;
/** \brief Set or reset the assert() callback of the environment.
*
* Does nothing if libmdbx was built with MDBX_DEBUG=0 or with NDEBUG,
* and will return `MDBX_ENOSYS` in such case.
*
* \param [in] env An environment handle returned by mdbx_env_create().
* \param [in] func An MDBX_assert_func function, or 0.
*
* \returns A non-zero error value on failure and 0 on success. */
LIBMDBX_API int mdbx_env_set_assert(MDBX_env *env, MDBX_assert_func *func);
/** \brief Dump given MDBX_val to the buffer
*
* Dumps it as string if value is printable (all bytes in the range 0x20..0x7E),
* otherwise made hexadecimal dump. Requires at least 4 byte length buffer.
*
* \returns One of:
* - NULL if given buffer size less than 4 bytes;
* - pointer to constant string if given value NULL or empty;
* - otherwise pointer to given buffer. */
LIBMDBX_API const char *mdbx_dump_val(const MDBX_val *key, char *const buf,
const size_t bufsize);
/** \brief Panics with message and causes abnormal process termination. */
LIBMDBX_API void mdbx_panic(const char *fmt, ...) MDBX_PRINTF_ARGS(1, 2);
/** @} end of logging & debug */
/** \brief Environment flags
* \ingroup c_opening
* \anchor env_flags
* \see mdbx_env_open() \see mdbx_env_set_flags() */
enum MDBX_env_flags_t {
MDBX_ENV_DEFAULTS = 0,
/** No environment directory.
*
* By default, MDBX creates its environment in a directory whose pathname is
* given in path, and creates its data and lock files under that directory.
* With this option, path is used as-is for the database main data file.
* The database lock file is the path with "-lck" appended.
*
* - with `MDBX_NOSUBDIR` = in a filesystem we have the pair of MDBX-files
* which names derived from given pathname by appending predefined suffixes.
*
* - without `MDBX_NOSUBDIR` = in a filesystem we have the MDBX-directory with
* given pathname, within that a pair of MDBX-files with predefined names.
*
* This flag affects only at new environment creating by \ref mdbx_env_open(),
* otherwise at opening an existing environment libmdbx will choice this
* automatically. */
MDBX_NOSUBDIR = UINT32_C(0x4000),
/** Read only mode.
*
* Open the environment in read-only mode. No write operations will be
* allowed. MDBX will still modify the lock file - except on read-only
* filesystems, where MDBX does not use locks.
*
* - with `MDBX_RDONLY` = open environment in read-only mode.
* MDBX supports pure read-only mode (i.e. without opening LCK-file) only
* when environment directory and/or both files are not writable (and the
* LCK-file may be missing). In such case allowing file(s) to be placed
* on a network read-only share.
*
* - without `MDBX_RDONLY` = open environment in read-write mode.
*
* This flag affects only at environment opening but can't be changed after.
*/
MDBX_RDONLY = UINT32_C(0x20000),
/** Open environment in exclusive/monopolistic mode.
*
* `MDBX_EXCLUSIVE` flag can be used as a replacement for `MDB_NOLOCK`,
* which don't supported by MDBX.
* In this way, you can get the minimal overhead, but with the correct
* multi-process and multi-thread locking.
*
* - with `MDBX_EXCLUSIVE` = open environment in exclusive/monopolistic mode
* or return \ref MDBX_BUSY if environment already used by other process.
* The main feature of the exclusive mode is the ability to open the
* environment placed on a network share.
*
* - without `MDBX_EXCLUSIVE` = open environment in cooperative mode,
* i.e. for multi-process access/interaction/cooperation.
* The main requirements of the cooperative mode are:
*
* 1. data files MUST be placed in the LOCAL file system,
* but NOT on a network share.
* 2. environment MUST be opened only by LOCAL processes,
* but NOT over a network.
* 3. OS kernel (i.e. file system and memory mapping implementation) and
* all processes that open the given environment MUST be running
* in the physically single RAM with cache-coherency. The only
* exception for cache-consistency requirement is Linux on MIPS
* architecture, but this case has not been tested for a long time).
*
* This flag affects only at environment opening but can't be changed after.
*/
MDBX_EXCLUSIVE = UINT32_C(0x400000),
/** Using database/environment which already opened by another process(es).
*
* The `MDBX_ACCEDE` flag is useful to avoid \ref MDBX_INCOMPATIBLE error
* while opening the database/environment which is already used by another
* process(es) with unknown mode/flags. In such cases, if there is a
* difference in the specified flags (\ref MDBX_NOMETASYNC,
* \ref MDBX_SAFE_NOSYNC, \ref MDBX_UTTERLY_NOSYNC, \ref MDBX_LIFORECLAIM,
* \ref MDBX_COALESCE and \ref MDBX_NORDAHEAD), instead of returning an error,
* the database will be opened in a compatibility with the already used mode.
*
* `MDBX_ACCEDE` has no effect if the current process is the only one either
* opening the DB in read-only mode or other process(es) uses the DB in
* read-only mode. */
MDBX_ACCEDE = UINT32_C(0x40000000),
/** Map data into memory with write permission.
*
* Use a writeable memory map unless \ref MDBX_RDONLY is set. This uses fewer
* mallocs and requires much less work for tracking database pages, but
* loses protection from application bugs like wild pointer writes and other
* bad updates into the database. This may be slightly faster for DBs that
* fit entirely in RAM, but is slower for DBs larger than RAM. Also adds the
* possibility for stray application writes thru pointers to silently
* corrupt the database.
*
* - with `MDBX_WRITEMAP` = all data will be mapped into memory in the
* read-write mode. This offers a significant performance benefit, since the
* data will be modified directly in mapped memory and then flushed to disk
* by single system call, without any memory management nor copying.
*
* - without `MDBX_WRITEMAP` = data will be mapped into memory in the
* read-only mode. This requires stocking all modified database pages in
* memory and then writing them to disk through file operations.
*
* \warning On the other hand, `MDBX_WRITEMAP` adds the possibility for stray
* application writes thru pointers to silently corrupt the database.
*
* \note The `MDBX_WRITEMAP` mode is incompatible with nested transactions,
* since this is unreasonable. I.e. nested transactions requires mallocation
* of database pages and more work for tracking ones, which neuters a
* performance boost caused by the `MDBX_WRITEMAP` mode.
*
* This flag affects only at environment opening but can't be changed after.
*/
MDBX_WRITEMAP = UINT32_C(0x80000),
/** Tie reader locktable slots to read-only transactions
* instead of to threads.
*
* Don't use Thread-Local Storage, instead tie reader locktable slots to
* \ref MDBX_txn objects instead of to threads. So, \ref mdbx_txn_reset()