Acknowledgements:
-----------------
- [Mahlon E. Smith](https://github.com/mahlonsmith) for [Ruby bindings](https://rubygems.org/gems/mdbx/).
- [Alex Sharov](https://github.com/AskAlexSharov) for [mdbx-go](https://github.com/torquem-ch/mdbx-go), bug reporting and testing.
- [Artem Vorotnikov](https://github.com/vorot93) for bug reporting and PR.
- [Paolo Rebuffo](https://www.linkedin.com/in/paolo-rebuffo-8255766/), [Alexey Akhunov](https://github.com/AlexeyAkhunov) and Mark Grosberg for donations.
- [Noel Kuntze](https://github.com/Thermi) for preliminary [Python bindings](https://github.com/Thermi/libmdbx/tree/python-bindings)
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](https://rubygems.org/gems/mdbx/) is available now by [Mahlon E. Smith](https://github.com/mahlonsmith).
- 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](https://en.wikipedia.org/wiki/Cache_replacement_policies#Least_recently_used_(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](https://github.com/Thermi/libmdbx/tree/python-bindings) is available now
by [Noel Kuntze](https://github.com/Thermi) (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:
------
- Fixed performance regression due non-optimal C11 atomics usage (https://github.com/erthink/libmdbx/issues/160).
- Fixed "reincarnation" of subDB after it deletion (https://github.com/erthink/libmdbx/issues/168).
- Fixed (disallowing) implicit subDB deletion via operations on `@MAIN`'s DBI-handle.
- Fixed a crash of `mdbx_env_info_ex()` in case of a call for a non-open environment (https://github.com/erthink/libmdbx/issues/171).
- Fixed the selecting/adjustment values inside `mdbx_env_set_geometry()` for implicit out-of-range cases (https://github.com/erthink/libmdbx/issues/170).
- Fixed `mdbx_env_set_option()` for set initial and limit size of dirty page list ((https://github.com/erthink/libmdbx/issues/179).
- Fixed an unreasonably huge default upper limit for DB geometry (https://github.com/erthink/libmdbx/issues/183).
- Fixed `constexpr` specifier for the `slice::invalid()`.
- Fixed (no)readahead auto-handling (https://github.com/erthink/libmdbx/issues/164).
- Fixed non-alloy build for Windows.
- Switched to using Heap-functions instead of LocalAlloc/LocalFree on Windows.
- Fixed `mdbx_env_stat_ex()` to returning statistics of the whole environment instead of MainDB only (https://github.com/erthink/libmdbx/issues/190).
- Fixed building by GCC 4.8.5 (added workaround for a preprocessor's bug).
- Fixed building C++ part for iOS <= 13.0 (unavailability of `std::filesystem::path`).
- Fixed building for Windows target versions prior to Windows Vista (`WIN32_WINNT < 0x0600`).
- Fixed building by MinGW for Windows (https://github.com/erthink/libmdbx/issues/155).
TODO for a next releases:
-------------------------
- [Get rid of dirty-pages list in MDBX_WRITEMAP mode](https://github.com/erthink/libmdbx/issues/193).
- [Large/Overflow pages accounting for dirty-room](https://github.com/erthink/libmdbx/issues/192).
- [C++ Buffer issue](https://github.com/erthink/libmdbx/issues/191).
- Finalize C++ API (few typos and trivia bugs are still likely for now).
- [Support for RAW devices](https://github.com/erthink/libmdbx/issues/124).
- [Test framework issue](https://github.com/erthink/libmdbx/issues/127).
- [Support MessagePack for Keys & Values](https://github.com/erthink/libmdbx/issues/115).
- [Engage new terminology](https://github.com/erthink/libmdbx/issues/137).
- Packages for [Astra Linux](https://astralinux.ru/), [ALT Linux](https://www.altlinux.org/), [ROSA Linux](https://www.rosalinux.ru/), Fedora/RHEL, Debian/Ubuntu.
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
Acknowledgements:
-----------------
- Jens Alfke (Mobile Architect at [Couchbase](https://www.couchbase.com/)) for [NimDBX](https://github.com/snej/nimdbx).
- Clément Renault (CTO at [MeiliSearch](https://www.meilisearch.com/)) for [mdbx-rs](https://github.com/Kerollmops/mdbx-rs).
- Alex Sharov (Go-Lang Teach Lead at [TurboGeth/Ethereum](https://ethereum.org/)) for an extreme test cases and bug reporting.
- George Hazan (CTO at [Miranda NG](https://www.miranda-ng.org/)) for bug reporting.
- [Positive Technologies](https://www.ptsecurity.com/) for funding and [The Standoff](https://standoff365.com/).
Added features:
---------------
- Provided package for [buildroot](https://buildroot.org/).
- Binding for Nim is [available](https://github.com/snej/nimdbx) 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.
TODO for v0.9.3:
----------------
- Engage new terminology (https://github.com/erthink/libmdbx/issues/137).
- Rework/speedup the implementation of the dirty page list (lazy compactification, lazy sorting via merge).
- Resolve few TODOs (https://github.com/erthink/libmdbx/issues/123, https://github.com/erthink/libmdbx/issues/124, https://github.com/erthink/libmdbx/issues/127, https://github.com/erthink/libmdbx/issues/128, https://github.com/erthink/libmdbx/issues/132, https://github.com/erthink/libmdbx/issues/115).
- Finalize C++ API (few typos and trivia bugs are still likely for now).
- Packages for ROSA Linux, ALT Linux, Fedora/RHEL, Debian/Ubuntu.
Change-Id: I1f0ac4505052f169e36b326243e5d56497b9c037
Signed-off-by: Leonid Yuriev <leo@yuriev.ru>
Added features:
- Preliminary C++ API with support for C++17 polymorphic allocators.
- [Online C++ API reference](https://erthink.github.io/libmdbx/) 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.
TODO for next version(s):
- Rework/speedup the implementation of the dirty page list (lazy compactification, lazy sorting via merge).
- Finalize C++ API (few typos and trivia bugs are likely for now).
- Packages for ROSA Linux, ALT Linux, Fedora/RHEL, Debian/Ubuntu.
Change-Id: I668d77e4545d444b60708b8c64a66ce43b2c56a0
At least the MSVC 19.27.29111.0 hang up during code generation/optimization due to its own internal errors.
Related to https://github.com/erthink/libmdbx/issues/116
Change-Id: I016769b38dea800da5450bd33fb241f145ff24da
The LCK file is re-created at every opportunity when the process that
opens the database is the only one that works with it. Thus the change
of the format of the file LCK creates only minimal compatibility
problems.
Applications using different versions of _libmdbx_ will be able to work
with one database alternately, but not at the same time. This appears to
be an acceptable inconvenience in exchange for new features.
Change-Id: I9414b3fffd53d5519c8172c57345b1eaf6e51c77
