snowflake

Snowflake is a network service for generating unique ID numbers at high scale with some simple guarantees.

Goal

• developing a c library package.
• quickly use as a CLI application.
• extension to lua.
• extension to go.

Installation

There are three ways to use snowflake:

• Library
• CLI application
• Lua extension

Library

In this way, you can use snowflake as a static library in your project.

mkdir build && cd build
cmake ..

make snowflake_lib

Then you can copy the build/libsnowflake.a to your project or install it to your system manually.

CLI application

In this way, you can use snowflake as a CLI application.

mkdir build && cd build
cmake ..

make snowflake_cli

Then you can copy the build/cmd/snowflake/snowflake to your system path.

Lua extension

In this way, you can use snowflake as a lua extension.

mkdir build && cd build
cmake ..

make snowflake_lua

Then you can copy the build/contrib/lua/snowflake.so to your lua package.cpath.

Generation process

Each time you generate an ID, it works, like this.

• A timestamp with millisecond precision is stored using 41 bits of the ID.
• Then the machineID is added in subsequent bits.
• Then the counter is added, starting at 0 and incrementing for each ID generated in the same millisecond. If you generate enough IDs in the same millisecond that the sequence would roll over or overfill then the generate function will pause until the next millisecond.

References

• twitter-snowflake
• thanks to bwmarrin/snowflake