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ChangeLog

TODO

v0.11.3 (underway)

Acknowledgements:

New features, extensions and improvements:

  • Added mdbx_cursor_get_batch().
  • Added MDBX_SET_UPPERBOUND.

Fixes:

  • Disabled C++20 concepts for stupid AppleClang 13.x
  • Fixed internal collision of MDBX_SHRINK_ALLOWED with MDBX_ACCEDE.

Minors:

  • Fixed returning MDBX_RESULT_TRUE (unexpected -1) from mdbx_env_set_option().
  • Added mdbx_env_get_syncbytes() and mdbx_env_get_syncperiod().
  • Clarified description of MDBX_INTEGERKEY.
  • Reworked/simplified mdbx_env_sync_internal().
  • Fixed extra assertion inside mdbx_cursor_put() for MDBX_DUPFIXED cases.
  • Avoiding extra looping inside mdbx_env_info_ex().
  • Explicitly enabled core dumps from stochastic tests scripts on Linux.
  • Fixed mdbx_override_meta() to avoid false-positive assertions.

v0.11.2 at 2021-12-02

Acknowledgements:

Fixes:

Minors:

  • Fixed constexpr-related macros for legacy compilers.
  • Allowed to define 'CMAKE_CXX_STANDARD` using an environment variable.
  • Simplified collection statistics of page operation .
  • Added MDBX_FORCE_BUILD_AS_MAIN_PROJECT cmake option.
  • Remove unneeded #undef P_DIRTY.

v0.11.1 at 2021-10-23

Backward compatibility break:

The database format signature has been changed to prevent forward-interoperability with an previous releases, which may lead to a false positive diagnosis of database corruption due to flaws of an old library versions.

This change is mostly invisible:

  • previously versions are unable to read/write a new DBs;
  • but the new release is able to handle an old DBs and will silently upgrade ones.

Acknowledgements:

v0.10.5 at 2021-10-13 (obsolete, please use v0.11.1)

Unfortunately, the v0.10.5 accidentally comes not full-compatible with previous releases:

  • v0.10.5 can read/processing DBs created by previous releases, i.e. the backward-compatibility is provided;
  • however, previous releases may lead to false-corrupted state with DB that was touched by v0.10.5, i.e. the forward-compatibility is broken for v0.10.4 and earlier.

This cannot be fixed, as it requires fixing past versions, which as a result we will just get a current version. Therefore, it is recommended to use v0.11.1 instead of v0.10.5.

Acknowledgements:

Fixes:

  • Fixed unaligned access regression after the #pragma pack fix for modern compilers.
  • Added UBSAN-test to CI to avoid a regression(s) similar to lately fixed.
  • Fixed possibility of meta-pages clashing after manually turn to a particular meta-page using mdbx_chk utility.

Minors:

  • Refined handling of weak or invalid meta-pages while a DB opening.
  • Refined providing information for the @MAIN and @GC sub-databases of a last committed modification transaction's ID.

v0.10.4 at 2021-10-10

Acknowledgements:

Fixes:

  • Fixed possibility of looping update GC during transaction commit (no public issue since the problem was discovered inside Positive Technologies).
  • Fixed #pragma pack to avoid provoking some compilers to generate code with unaligned access.
  • Fixed noexcept for potentially throwing txn::put() of C++ API.

Minors:

  • Added stochastic test script for checking small transactions cases.
  • Removed extra transaction commit/restart inside test framework.
  • In debugging builds fixed a too small (single page) by default DB shrink threshold.

v0.10.3 at 2021-08-27

Acknowledgements:

Extensions and improvements:

  • Added cursor::erase() overloads for key and for key-value.
  • Resolve minor Coverity Scan issues (no fixes but some hint/comment were added).
  • Resolve minor UndefinedBehaviorSanitizer issues (no fixes but some workaround were added).

Fixes:

Minors:

  • Fixed getting revision number from middle of history during amalgamation (GNU Makefile).
  • Fixed search GCC tools for LTO (CMake scripts).
  • Fixed/reorder dirs list for search CLANG tools for LTO (CMake scripts).
  • Fixed/workarounds for CLANG < 9.x
  • Fixed CMake warning about compatibility with 3.8.2

v0.10.2 at 2021-07-26

Acknowledgements:

New features, extensions and improvements:

  • Allow to predefine/override MDBX_BUILD_TIMESTAMP for builds reproducibility.
  • Added options support for long-stochastic script.
  • Avoided MDBX_TXN_FULL error for large transactions when possible.
  • The MDBX_READERS_LIMIT increased to 32767.
  • Raise MDBX_TOO_LARGE under Valgrind/ASAN if being opened DB is 100 larger than RAM (to avoid hangs and OOM).
  • Minimized the size of poisoned/unpoisoned regions to avoid Valgrind/ASAN stuck.
  • Added more workarounds for QEMU for testing builds for 32-bit platforms, Alpha and Sparc architectures.
  • mdbx_chk now skips iteration & checking of DB' records if corresponding page-tree is corrupted (to avoid SIGSEGV, ASAN failures, etc).
  • Added more checks for rare/fuzzing corruption cases.

Backward compatibility break:

  • Use file VERSION.txt for version information instead of VERSION to avoid collision with #include <version>.
  • Rename slice::from/to_FOO_bytes() to `slice::envisage_from/to_FOO_length()'.
  • Rename MDBX_TEST_EXTRA make's variable to MDBX_SMOKE_EXTRA.
  • Some details of the C++ API have been changed for subsequent freezing.

Fixes:

v0.10.1 at 2021-06-01

Acknowledgements:

New features:

  • Added -p option to mdbx_stat utility for printing page operations statistic.
  • Added explicit checking for and warning about using unfit github's archives.
  • Added fallback from OFD locking to legacy non-OFD POSIX file locks on an EINVAL error.
  • Added Plan 9 network file system to the whitelist for an ability to open a DB in exclusive mode.
  • Support for opening from WSL2 environment a DB hosted on Windows drive and mounted via DrvFs (i.e by Plan 9 noted above).

Fixes:

v0.10.0 at 2021-05-09

Acknowledgements:

New features:

  • Added mdbx_env_set_option() and mdbx_env_get_option() for controls various runtime options for an environment (announce of this feature was missed in a previous news).
  • Added MDBX_DISABLE_PAGECHECKS build option to disable some checks to reduce an overhead and detection probability of database corruption to a values closer to the LMDB. The MDBX_DISABLE_PAGECHECKS=1 provides a performance boost of about 10% in CRUD scenarios, and conjointly with the MDBX_ENV_CHECKPID=0 and MDBX_TXN_CHECKOWNER=0 options can yield up to 30% more performance compared to LMDB.
  • Using float point (exponential quantized) representation for internal 16-bit values of grow step and shrink threshold when huge ones (https://github.com/erthink/libmdbx/issues/166). To minimize the impact on compatibility, only the odd values inside the upper half of the range (i.e. 32769..65533) are used for the new representation.
  • Added the mdbx_drop similar to LMDB command-line tool to purge or delete (sub)database(s).
  • Ruby bindings is available now by Mahlon E. Smith.
  • Added MDBX_ENABLE_MADVISE build option which controls the use of POSIX madvise() hints and friends.
  • The internal node sizes were refined, resulting in a reduction in large/overflow pages in some use cases and a slight increase in limits for a keys size to ≈½ of page size.
  • Added to mdbx_chk output number of keys/items on pages.
  • Added explicit install-strip and install-no-strip targets to the Makefile (https://github.com/erthink/libmdbx/pull/180).
  • Major rework page splitting (af9b7b5605) for
    • An "auto-appending" feature upon insertion for both ascending and descending key sequences. As a result, the optimality of page filling increases significantly (more densely, less slackness) while inserting ordered sequences of keys,
    • A "splitting at middle" to make page tree more balanced on average.
  • Added mdbx_get_sysraminfo() to the API.
  • Added guessing a reasonable maximum DB size for the default upper limit of geometry (https://github.com/erthink/libmdbx/issues/183).
  • Major rework internal labeling of a dirty pages (958fd5b947) for a "transparent spilling" feature with the gist to make a dirty pages be ready to spilling (writing to a disk) without further altering ones. Thus in the MDBX_WRITEMAP mode the OS kernel able to oust dirty pages to DB file without further penalty during transaction commit. As a result, page swapping and I/O could be significantly reduced during extra large transactions and/or lack of memory.
  • Minimized reading leaf-pages during dropping subDB(s) and nested trees.
  • Major rework a spilling of dirty pages to support LRU policy and prioritization for a large/overflow pages.
  • Statistics of page operations (split, merge, copy, spill, etc) now available through mdbx_env_info_ex().
  • Auto-setup limit for length of dirty pages list (MDBX_opt_txn_dp_limit option).
  • Support make options to list available build options.
  • Support make help to list available make targets.
  • Silently make's build by default.
  • Preliminary Python bindings is available now by Noel Kuntze (https://github.com/erthink/libmdbx/issues/147).

Backward compatibility break:

  • The MDBX_AVOID_CRT build option was renamed to MDBX_WITHOUT_MSVC_CRT. This option is only relevant when building for Windows.
  • The mdbx_env_stat() always, and mdbx_env_stat_ex() when called with the zeroed transaction parameter, now internally start temporary read transaction and thus may returns MDBX_BAD_RSLOT error. So, just never use deprecated mdbx_env_stat()' and call mdbx_env_stat_ex()` with transaction parameter.
  • The build option MDBX_CONFIG_MANUAL_TLS_CALLBACK was removed and now just a non-zero value of the MDBX_MANUAL_MODULE_HANDLER macro indicates the requirement to manually call mdbx_module_handler() when loading libraries and applications uses statically linked libmdbx on an obsolete Windows versions.

Fixes:

v0.9.3 at 2021-02-02

Acknowledgements:

Removed options and features:

  • Drop MDBX_HUGE_TRANSACTIONS build-option (now no longer required).

New features:

  • Package for FreeBSD is available now by Mahlon E. Smith.
  • New API functions to get/set various options (https://github.com/erthink/libmdbx/issues/128):
    • the maximum number of named databases for the environment;
    • the maximum number of threads/reader slots;
    • threshold (since the last unsteady commit) to force flush the data buffers to disk;
    • relative period (since the last unsteady commit) to force flush the data buffers to disk;
    • limit to grow a list of reclaimed/recycled page's numbers for finding a sequence of contiguous pages for large data items;
    • limit to grow a cache of dirty pages for reuse in the current transaction;
    • limit of a pre-allocated memory items for dirty pages;
    • limit of dirty pages for a write transaction;
    • initial allocation size for dirty pages list of a write transaction;
    • maximal part of the dirty pages may be spilled when necessary;
    • minimal part of the dirty pages should be spilled when necessary;
    • how much of the parent transaction dirty pages will be spilled while start each child transaction;
  • Unlimited/Dynamic size of retired and dirty page lists (https://github.com/erthink/libmdbx/issues/123).
  • Added -p option (purge subDB before loading) to mdbx_load tool.
  • Reworked spilling of large transaction and committing of nested transactions:
    • page spilling code reworked to avoid the flaws and bugs inherited from LMDB;
    • limit for number of dirty pages now is controllable at runtime;
    • a spilled pages, including overflow/large pages, now can be reused and refunded/compactified in nested transactions;
    • more effective refunding/compactification especially for the loosed page cache.
  • Added MDBX_ENABLE_REFUND and MDBX_PNL_ASCENDING internal/advanced build options.
  • Added mdbx_default_pagesize() function.
  • Better support architectures with a weak/relaxed memory consistency model (ARM, AARCH64, PPC, MIPS, RISC-V, etc) by means C11 atomics.
  • Speed up page number lists and dirty page lists (https://github.com/erthink/libmdbx/issues/132).
  • Added LIBMDBX_NO_EXPORTS_LEGACY_API build option.

Fixes:

v0.9.2 at 2020-11-27

Acknowledgements:

Added features:

  • Provided package for buildroot.
  • Binding for Nim is available now by Jens Alfke.
  • Added mdbx_env_delete() for deletion an environment files in a proper and multiprocess-safe way.
  • Added mdbx_txn_commit_ex() with collecting latency information.
  • Fast completion pure nested transactions.
  • Added LIBMDBX_INLINE_API macro and inline versions of some API functions.
  • Added mdbx_cursor_copy() function.
  • Extended tests for checking cursor tracking.
  • Added MDBX_SET_LOWERBOUND operation for mdbx_cursor_get().

Fixes:

  • Fixed missing installation of mdbx.h++.
  • Fixed use of obsolete __noreturn.
  • Fixed use of yield instruction on ARM if unsupported.
  • Added pthread workaround for buggy toolchain/cmake/buildroot.
  • Fixed use of pthread_yield() for non-GLIBC.
  • Fixed use of RegGetValueA() on Windows 2000/XP.
  • Fixed use of GetTickCount64() on Windows 2000/XP.
  • Fixed opening DB on a network shares (in the exclusive mode).
  • Fixed copy&paste typos.
  • Fixed minor false-positive GCC warning.
  • Added workaround for broken DEFINE_ENUM_FLAG_OPERATORS from Windows SDK.
  • Fixed cursor state after multimap/dupsort repeated deletes (https://github.com/erthink/libmdbx/issues/121).
  • Added SIGPIPE suppression for internal thread during mdbx_env_copy().
  • Fixed extra-rare MDBX_KEY_EXIST error during mdbx_commit() (https://github.com/erthink/libmdbx/issues/131).
  • Fixed spilled pages checking (https://github.com/erthink/libmdbx/issues/126).
  • Fixed mdbx_load for 'plain text' and without -s name cases (https://github.com/erthink/libmdbx/issues/136).
  • Fixed save/restore/commit of cursors for nested transactions.
  • Fixed cursors state in rare/special cases (move next beyond end-of-data, after deletion and so on).
  • Added workaround for MSVC 19.28 (Visual Studio 16.8) (but may still hang during compilation).
  • Fixed paranoidal Clang C++ UB for bitwise operations with flags defined by enums.
  • Fixed large pages checking (for compatibility and to avoid false-positive errors from mdbx_chk).
  • Added workaround for Wine (https://github.com/miranda-ng/miranda-ng/issues/1209).
  • Fixed ERROR_NOT_SUPPORTED while opening DB by UNC pathnames (https://github.com/miranda-ng/miranda-ng/issues/2627).
  • Added handling EXCEPTION_POSSIBLE_DEADLOCK condition for Windows.

v0.9.1 2020-09-30

Added features:

  • Preliminary C++ API with support for C++17 polymorphic allocators.
  • Online C++ API reference by Doxygen.
  • Quick reference for Insert/Update/Delete operations.
  • Explicit MDBX_SYNC_DURABLE to sync modes for API clarity.
  • Explicit MDBX_ALLDUPS and MDBX_UPSERT for API clarity.
  • Support for read transactions preparation (MDBX_TXN_RDONLY_PREPARE flag).
  • Support for cursor preparation/(pre)allocation and reusing (mdbx_cursor_create() and mdbx_cursor_bind() functions).
  • Support for checking database using specified meta-page (see mdbx_chk -h).
  • Support for turn to the specific meta-page after checking (see mdbx_chk -h).
  • Support for explicit reader threads (de)registration.
  • The mdbx_txn_break() function to explicitly mark a transaction as broken.
  • Improved handling of corrupted databases by mdbx_chk utility and mdbx_walk_tree() function.
  • Improved DB corruption detection by checking parent-page-txnid.
  • Improved opening large DB (> 4Gb) from 32-bit code.
  • Provided pure-function and const-function attributes to C API.
  • Support for user-settable context for transactions & cursors.
  • Revised API and documentation related to Handle-Slow-Readers callback feature.

Deprecated functions and flags:

  • For clarity and API simplification the MDBX_MAPASYNC flag is deprecated. Just use MDBX_SAFE_NOSYNC or MDBX_UTTERLY_NOSYNC instead of it.
  • MDBX_oom_func, mdbx_env_set_oomfunc() and mdbx_env_get_oomfunc() replaced with MDBX_hsr_func, mdbx_env_get_hsr and mdbx_env_get_hsr().

Fixes:

  • Fix mdbx_strerror() for MDBX_BUSY error (no error description is returned).
  • Fix update internal meta-geo information in read-only mode (EACCESS or EBADFD error).
  • Fix mdbx_page_get() null-defer when DB corrupted (crash by SIGSEGV).
  • Fix mdbx_env_open() for re-opening after non-fatal errors (mdbx_chk unexpected failures).
  • Workaround for MSVC 19.27 static_assert() bug.
  • Doxygen descriptions and refinement.
  • Update Valgrind's suppressions.
  • Workaround to avoid infinite loop of 'nested' testcase on MIPS under QEMU.
  • Fix a lot of typos & spelling (Thanks to Josh Soref for PR).
  • Fix getopt() messages for Windows (Thanks to Andrey Sporaw for reporting).
  • Fix MSVC compiler version requirements (Thanks to Andrey Sporaw for reporting).
  • Workarounds for QEMU's bugs to run tests for cross-builded library under QEMU.
  • Now C++ compiler optional for building by CMake.

v0.9.0 2020-07-31 (not a release, but API changes)

Added features:

  • Online C API reference by Doxygen.
  • Separated enums for environment, sub-databases, transactions, copying and data-update flags.

Deprecated functions and flags:

  • Usage of custom comparators and the mdbx_dbi_open_ex() are deprecated, since such databases couldn't be checked by the mdbx_chk utility. Please use the value-to-key functions to provide keys that are compatible with the built-in libmdbx comparators.

v0.8.2 2020-07-06

  • Added support multi-opening the same DB in a process with SysV locking (BSD).
  • Fixed warnings & minors for LCC compiler (E2K).
  • Enabled to simultaneously open the same database from processes with and without the MDBX_WRITEMAP option.
  • Added key-to-value, mdbx_get_keycmp() and mdbx_get_datacmp() functions (helpful to avoid using custom comparators).
  • Added ENABLE_UBSAN CMake option to enabling the UndefinedBehaviorSanitizer from GCC/CLANG.
  • Workaround for CLANG bug.
  • Returning MDBX_CORRUPTED in case all meta-pages are weak and no other error.
  • Refined mode bits while auto-creating LCK-file.
  • Avoids unnecessary database file re-mapping in case geometry changed by another process(es). From the user's point of view, the MDBX_UNABLE_EXTEND_MAPSIZE error will now be returned less frequently and only when using the DB in the current process really requires it to be reopened.
  • Remapping on-the-fly and of the database file was implemented. Now remapping with a change of address is performed automatically if there are no dependent readers in the current process.

v0.8.1 2020-06-12

  • Minor change versioning. The last number in the version now means the number of commits since last release/tag.
  • Provide ChangeLog file.
  • Fix for using libmdbx as a C-only sub-project with CMake.
  • Fix mdbx_env_set_geometry() for case it is called from an opened environment outside of a write transaction.
  • Add support for huge transactions and MDBX_HUGE_TRANSACTIONS build-option (default OFF).
  • Refine LTO (link time optimization) for clang.
  • Force enabling exceptions handling for MSVC (/EHsc option).

v0.8.0 2020-06-05

  • Support for Android/Bionic.
  • Support for iOS.
  • Auto-handling MDBX_NOSUBDIR while opening for any existing database.
  • Engage github-actions to make release-assets.
  • Clarify API description.
  • Extended keygen-cases in stochastic test.
  • Fix fetching of first/lower key from LEAF2-page during page merge.
  • Fix missing comma in array of error messages.
  • Fix div-by-zero while copy-with-compaction for non-resizable environments.
  • Fixes & enhancements for custom-comparators.
  • Fix MDBX_WITHOUT_MSVC_CRT option and missing ntdll.def.
  • Fix mdbx_env_close() to work correctly called concurrently from several threads.
  • Fix null-deref in an ASAN-enabled builds while opening the environment with error and/or read-only.
  • Fix AddressSanitizer errors after closing the environment.
  • Fix/workaround to avoid GCC 10.x pedantic warnings.
  • Fix using ENODATA for FreeBSD.
  • Avoid invalidation of DBI-handle(s) when it just closes.
  • Avoid using pwritev() for single-writes (up to 10% speedup for some kernels & scenarios).
  • Avoiding MDBX_UTTERLY_NOSYNC as result of flags merge.
  • Add mdbx_dbi_dupsort_depthmask() function.
  • Add MDBX_CP_FORCE_RESIZEABLE option.
  • Add deprecated MDBX_MAP_RESIZED for compatibility.
  • Add MDBX_BUILD_TOOLS option (default ON).
  • Refine mdbx_dbi_open_ex() to safe concurrently opening the same handle from different threads.
  • Truncate clk-file during environment closing. So a zero-length lck-file indicates that the environment was closed properly.
  • Refine mdbx_update_gc() for huge transactions with small sizes of database page.
  • Extends dump/load to support all MDBX attributes.
  • Avoid upsertion the same key-value data, fix related assertions.
  • Rework min/max length checking for keys & values.
  • Checking the order of keys on all pages during checking.
  • Support CFLAGS_EXTRA make-option for convenience.
  • Preserve the last txnid while copying with compactification.
  • Auto-reset running transaction in mdbx_txn_renew().
  • Automatically abort errored transaction in mdbx_txn_commit().
  • Auto-choose page size for large databases.
  • Rearrange source files, rework build, options-support by CMake.
  • Crutch for WSL1 (Windows subsystem for Linux).
  • Refine install/uninstall targets.
  • Support for Valgrind 3.14 and later.
  • Add check-analyzer check-ubsan check-asan check-leak targets to Makefile.
  • Minor fix/workaround to avoid UBSAN traps for memcpy(ptr, NULL, 0).
  • Avoid some GCC-analyzer false-positive warnings.

v0.7.0 2020-03-18

  • Workarounds for Wine (Windows compatibility layer for Linux).
  • MDBX_MAP_RESIZED renamed to MDBX_UNABLE_EXTEND_MAPSIZE.
  • Clarify API description, fix typos.
  • Speedup runtime checks in debug/checked builds.
  • Added checking for read/write transactions overlapping for the same thread, added MDBX_TXN_OVERLAPPING error and MDBX_DBG_LEGACY_OVERLAP option.
  • Added mdbx_key_from_jsonInteger(), mdbx_key_from_double(), mdbx_key_from_float(), mdbx_key_from_int64() and mdbx_key_from_int32() functions. See mdbx.h for description.
  • Fix compatibility (use zero for invalid DBI).
  • Refine/clarify error messages.
  • Avoids extra error messages "bad txn" from mdbx_chk when DB is corrupted.

v0.6.0 2020-01-21

  • Fix mdbx_load utility for custom comparators.
  • Fix checks related to MDBX_APPEND flag inside mdbx_cursor_put().
  • Refine/fix dbi_bind() internals.
  • Refine/fix handling STATUS_CONFLICTING_ADDRESSES.
  • Rework MDBX_DBG_DUMP option to avoid disk I/O performance degradation.
  • Add built-in help to test tool.
  • Fix mdbx_env_set_geometry() for large page size.
  • Fix env_set_geometry() for large pagesize.
  • Clarify API description & comments, fix typos.

v0.5.0 2019-12-31

  • Fix returning MDBX_RESULT_TRUE from page_alloc().
  • Fix false-positive ASAN issue.
  • Fix assertion for MDBX_NOTLS option.
  • Rework MADV_DONTNEED threshold.
  • Fix mdbx_chk utility for don't checking some numbers if walking on the B-tree was disabled.
  • Use page's mp_txnid for basic integrity checking.
  • Add MDBX_FORCE_ASSERTIONS built-time option.
  • Rework MDBX_DBG_DUMP to avoid performance degradation.
  • Rename MDBX_NOSYNC to MDBX_SAFE_NOSYNC for clarity.
  • Interpret ERROR_ACCESS_DENIED from OpenProcess() as 'process exists'.
  • Avoid using FILE_FLAG_NO_BUFFERING for compatibility with small database pages.
  • Added install section for CMake.

v0.4.0 2019-12-02

  • Support for Mac OSX, FreeBSD, NetBSD, OpenBSD, DragonFly BSD, OpenSolaris, OpenIndiana (AIX and HP-UX pending).
  • Use bootid for decisions of rollback.
  • Counting retired pages and extended transaction info.
  • Add MDBX_ACCEDE flag for database opening.
  • Using OFD-locks and tracking for in-process multi-opening.
  • Hot backup into pipe.
  • Support for cmake & amalgamated sources.
  • Fastest internal sort implementation.
  • New internal dirty-list implementation with lazy sorting.
  • Support for lazy-sync-to-disk with polling.
  • Extended key length.
  • Last update transaction number for each sub-database.
  • Automatic read ahead enabling/disabling.
  • More auto-compactification.
  • Using -fsanitize=undefined and -Wpedantic options.
  • Rework page merging.
  • Nested transactions.
  • API description.
  • Checking for non-local filesystems to avoid DB corruption.