Acknowledgements:
-----------------
- [Alex Sharov](https://github.com/AskAlexSharov) for reporting and testing.
- [Andrea Lanfranchi](https://github.com/AndreaLanfranchi) for reporting bugs.
- [Lionel Debroux](https://github.com/debrouxl) for fuzzing tests and reporting bugs.
- [Sergey Fedotov](https://github.com/SergeyFromHell/) for [`node-mdbx` NodeJS bindings](https://www.npmjs.com/package/node-mdbx).
- [Kris Zyp](https://github.com/kriszyp) for [`lmdbx-store` NodeJS bindings](https://github.com/kriszyp/lmdbx-store).
- [Noel Kuntze](https://github.com/Thermi) for [draft Python bindings](https://github.com/erthink/libmdbx/commits/python-bindings).
New features, extensions and improvements:
------------------------------------------
- [Allow to predefine/override `MDBX_BUILD_TIMESTAMP` for builds reproducibility](https://github.com/erthink/libmdbx/issues/201).
- 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](https://github.com/erthink/libmdbx/issues/217).
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:
------
- Fixed excess meta-pages checks in case `mdbx_chk` is called to check the DB for a specific meta page and thus could prevent switching to the selected meta page, even if the check passed without errors.
- Fixed [recursive use of SRW-lock on Windows cause by `MDBX_NOTLS` option](https://github.com/erthink/libmdbx/issues/203).
- Fixed [log a warning during a new DB creation](https://github.com/erthink/libmdbx/issues/205).
- Fixed [false-negative `mdbx_cursor_eof()` result](https://github.com/erthink/libmdbx/issues/207).
- Fixed [`make install` with non-GNU `install` utility (OSX, BSD)](https://github.com/erthink/libmdbx/issues/208).
- Fixed [installation by `CMake` in special cases by complete use `GNUInstallDirs`'s variables](https://github.com/erthink/libmdbx/issues/209).
- Fixed [C++ Buffer issue with `std::string` and alignment](https://github.com/erthink/libmdbx/issues/191).
- Fixed `safe64_reset()` for platforms without atomic 64-bit compare-and-swap.
- Fixed hang/shutdown on big-endian platforms without `__cxa_thread_atexit()`.
- Fixed [using bad meta-pages if DB was partially/recoverable corrupted](https://github.com/erthink/libmdbx/issues/217).
- Fixed extra `noexcept` for `buffer::&assign_reference()`.
- Fixed `bootid` generation on Windows for case of change system' time.
- Fixed [test framework keygen-related issue](https://github.com/erthink/libmdbx/issues/127).
Acknowledgements:
-----------------
- [Alexey Akhunov](https://github.com/AlexeyAkhunov) and [Alex Sharov](https://github.com/AskAlexSharov) for bug reporting and testing.
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.
Fixes:
------
- Fixed minor "foo not used" warnings from modern C++ compilers when building the C++ part of the library.
- Fixed confusing/messy errors when build library from unfit github's archives (https://github.com/erthink/libmdbx/issues/197).
- Fixed `#elsif` typo.
- Fixed rare unexpected `MDBX_PROBLEM` error during altering data in huge transactions due to wrong spilling/oust of dirty pages (https://github.com/erthink/libmdbx/issues/195).
Using float point (exponential quantized) representation for internal 16-bit values
of grow step and shrink threshold when huge ones
.
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.
Resolve https://github.com/erthink/libmdbx/issues/166
Change-Id: I273127c1842deef0d7d8885b55a805b1463556eb
Acknowledgements:
-----------------
- [Mahlon E. Smith](http://www.martini.nu/) for [FreeBSD port of libmdbx](https://svnweb.freebsd.org/ports/head/databases/mdbx/).
- [장세연](http://www.castis.com) for bug fixing and PR.
- [Clément Renault](https://github.com/Kerollmops/heed) for [Heed](https://github.com/Kerollmops/heed) fully typed Rust wrapper.
- [Alex Sharov](https://github.com/AskAlexSharov) for bug reporting.
- [Noel Kuntze](https://github.com/Thermi) for bug reporting.
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](https://en.cppreference.com/w/c/atomic).
- 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:
------
- Fixed missing cleanup (null assigned) in the C++ commit/abort (https://github.com/erthink/libmdbx/pull/143).
- Fixed `mdbx_realloc()` for case of nullptr and `MDBX_AVOID_CRT=ON` for Windows.
- Fixed the possibility to use invalid and renewed (closed & re-opened, dropped & re-created) DBI-handles (https://github.com/erthink/libmdbx/issues/146).
- Fixed 4-byte aligned access to 64-bit integers, including access to the `bootid` meta-page's field (https://github.com/erthink/libmdbx/issues/153).
- Fixed minor/potential memory leak during page flushing and unspilling.
- Fixed handling states of cursors's and subDBs's for nested transactions.
- Fixed page leak in extra rare case the list of retired pages changed during update GC on transaction commit.
- Fixed assertions to avoid false-positive UB detection by CLANG/LLVM (https://github.com/erthink/libmdbx/issues/153).
- Fixed `MDBX_TXN_FULL` and regressive `MDBX_KEYEXIST` during large transaction commit with `MDBX_LIFORECLAIM` (https://github.com/erthink/libmdbx/issues/123).
- Fixed auto-recovery (`weak->steady` with the same boot-id) when Database size at last weak checkpoint is large than at last steady checkpoint.
- Fixed operation on systems with unusual small/large page size, including PowerPC (https://github.com/erthink/libmdbx/issues/157).
TODO:
-----
- Engage new terminology (https://github.com/erthink/libmdbx/issues/137).
- Resolve few TODOs (https://github.com/erthink/libmdbx/issues/124, https://github.com/erthink/libmdbx/issues/127, https://github.com/erthink/libmdbx/issues/115).
- Finalize C++ API.
- Packages for [ROSA Linux](https://www.rosalinux.ru/), [ALT Linux](https://www.altlinux.org/), Fedora/RHEL, Debian/Ubuntu.
Change-Id: I414b8ef2e4b90e04fb344779c0e3f1b4bd1c06be
This done better support architectures with a weak/relaxed memory consistency model (ARM, AARCH64, PPC, MIPS, RISC-V, etc).
Change-Id: Iee831c8dc564f1d027ff84b0d6daa559325d5a9b
Historically, the page header provides 4-byte data alignment.
Therefore, unfortunately, the meta page data is also aligned on a 4-byte boundary, but contains 64-bit values.
This commit eliminates potentially unsafe access (SPARC, MIPS, etc) to these 64-bit values aligned on a 4-byte boundary.
Thus, a build with the `-fsanitize=undefined` now passes the tests both with CLANG 11 and GCC 10.
Change-Id: Ie441103e53ed96fd40507d8c0be0689e3fee69f5
