Леонид Юрьев (Leonid Yuriev)

Probably my English is not very good: 1. Any cursor created by `mdb_cursor_open()`, when it becomes unnecessary, must be explicitly freed by `mdbx_cursor_close()`. 2. Any cursor created by `mdb_cursor_open()`, may...

1. The `MDBX_page_type_t`, `MDBX_pgvisitor_func` and `mdbx_env_pgwalk` are an [internal/auxiliary ](https://github.com/leo-yuriev/libmdbx/blob/master/mdbx.h#L3245-L3246) API, i.e. shouldn't be used in a regular application. 2. The problems with [error codes](https://github.com/Kerollmops/mdbx-rs/blob/f913ba8d7e8b7ee75d8f409f16f417e2c634c316/src/bindings.rs#L3-L12) since libmdbx [defines an aliases](https://github.com/leo-yuriev/libmdbx/blob/master/mdbx.h#L538-L584)...

Please, use `stdint.h`. Otherwise it is a lot of the same troubles on Darwin, xBSD, etc...

> ``` > cc -O2 -g -Wall -Werror -Wextra -Wpedantic -ffunction-sections -fPIC -fvisibility=hidden -std=gnu11 -pthread -Wno-error=attributes -DNDEBUG=1 '-DMDBX_CONFIG_H="config.h"' -ULIBMDBX_EXPORTS -c mdbx.c -o mdbx-static.o > GNUmakefile:101: recipe for target 'mdbx-static.o' failed...

I just added an amalgamated source code check during `make dist`, and these changes have passed CI-check for Linux, MacOS and FreeBSD. This means that libmdbx's amalgamation script don't have...

Merged into https://github.com/leo-yuriev/dtoa-benchmark

В пофикшеном баге было указано что это дубликат, а после за полгода не воспроизвелось - видимо можно закрывать?

This is a problem, since java does not have 64-bit unsigned integers. Therefore wide multiplication (64x64 -> 128) will be unacceptably slow in java implementation.

It is not enough, anyway something like [`_mymum()`](https://github.com/OpenHFT/Zero-Allocation-Hashing/blob/master/src/main/java/net/openhft/hashing/WyHash.java#L26-L39) is needed. The proper way is provide [`_umul128()`](https://docs.microsoft.com/en-us/cpp/intrinsics/umul128) for Java.

In continue to #203, pre-requirement for #200.