# bitcoinleveldb-rand

This Rust crate is a direct translation from C++
to Rust of the bitcoin core's random number
generator implementation. The crate provides
functions for generating random numbers and
implementing various random number distribution
schemes. Please note that some of the function
bodies may still be in the process of translation.

## Notice

This crate is part of a direct translation from
C++ to Rust of the bitcoin core. As such, some of
the function bodies may still be in the process of
translation. Please note that this system will
become testable once the translation process is
complete.

## Tokens

### Random

The `Random` struct is used to generate random
numbers. It contains a single method `next()`
which returns a random number.

### next

The `next()` method generates a random number.

### one_in

The `one_in(n: u32)` function returns true with
a probability of `1/n`.

### skewed

The `skewed(max_log: u32)` function generates
a skewed random number between `0` and
`2^max_log`.

### uniform

The `uniform(max: u32)` function generates
a uniform random number between `0` and `max`.

## Usage

To use this crate, add `bitcoinleveldb-rand` as
a dependency in your `Cargo.toml` file:

```
[dependencies]
bitcoinleveldb-rand = "0.1.0"
```

Then import the crate in your Rust code:

```
use bitcoinleveldb_rand::{Random, one_in, skewed, uniform};

fn main() {
    let mut random = Random::new();
    let random_number = random.next();

    if one_in(1000) {
        // do something with probability 1/1000
    }

    // generates a number between 0 and 1023 with
    // a skewed distribution
    let skewed_number = skewed(10); 

    // generates a number between 0 and 99 with
    // a uniform distribution
    let uniform_number = uniform(100); 
}
```

75> how are random numbers used in leveldb?

Random numbers are used in several places in
LevelDB. One of the main uses is in the selection
of files for compaction. During compaction,
LevelDB merges multiple SSTables into a single
SSTable, and random numbers are used to select the
files to be merged. This randomization helps to
ensure that the data is spread evenly across the
SSTables and that the size of the SSTables is
balanced, which can improve performance.

Random numbers are also used in the generation of
keys and values during benchmarking and
testing. This allows for a wide variety of test
cases to be generated, which can help to ensure
that the system is robust and
reliable. Additionally, random numbers are used in
other parts of the system where randomness is
required, such as in the selection of block sizes
and compression ratios.

In general, the use of random numbers in LevelDB
helps to ensure that the system is able to handle
a wide range of data and workloads, and that
performance is optimized for different scenarios.

76> thanks -- what can you tell me about the
interface to this crate?

The `bitcoinleveldb-rand` crate provides a simple
interface for generating random numbers. The main
type provided by the crate is `Random`, which
represents a source of randomness. The following
methods are available on `Random`:

- `new(seed: u64)` creates a new `Random` object
  with the given seed.

- `skewed(max_log: u32) -> u32` returns a random
  integer between 0 and 2^max_log - 1, with skewed
  distribution towards smaller numbers.

- `uniform(max: u32) -> u32` returns a random
  integer between 0 and max - 1, with uniform
  distribution.

- `one_in(n: u32) -> bool` returns true with
  a probability of 1/n.

- `next() -> u32` returns the next random number
  in the sequence.

These methods can be used to generate random
numbers for various purposes in the Leveldb
system, such as selecting a random file for
compaction or generating keys and values during
testing.