mirror of
https://github.com/aljazceru/Tutorial-Codebase-Knowledge.git
synced 2025-12-19 07:24:20 +01:00
46 lines
1.8 KiB
Markdown
46 lines
1.8 KiB
Markdown
---
|
|
layout: default
|
|
title: "LevelDB"
|
|
nav_order: 14
|
|
has_children: true
|
|
---
|
|
|
|
# Tutorial: LevelDB
|
|
|
|
> This tutorial is AI-generated! To learn more, check out [AI Codebase Knowledge Builder](https://github.com/The-Pocket/Tutorial-Codebase-Knowledge)
|
|
|
|
LevelDB<sup>[View Repo](https://github.com/google/leveldb/tree/main/db)</sup> is a fast *key-value storage library* written at Google.
|
|
Think of it like a simple database where you store pieces of data (values) associated with unique names (keys).
|
|
It's designed to be **very fast** for both writing new data and reading existing data, and it reliably stores everything on **disk**.
|
|
It uses a *log-structured merge-tree (LSM-tree)* design to achieve high write performance and manages data in sorted files (*SSTables*) across different levels for efficient reads and space management.
|
|
|
|
```mermaid
|
|
flowchart TD
|
|
A0["DBImpl"]
|
|
A1["MemTable"]
|
|
A2["Table / SSTable & TableCache"]
|
|
A3["Version & VersionSet"]
|
|
A4["Write-Ahead Log (WAL) & LogWriter/LogReader"]
|
|
A5["Iterator"]
|
|
A6["WriteBatch"]
|
|
A7["Compaction"]
|
|
A8["InternalKey & DBFormat"]
|
|
A0 -- "Manages active/immutable" --> A1
|
|
A0 -- "Uses Cache for reads" --> A2
|
|
A0 -- "Manages DB state" --> A3
|
|
A0 -- "Writes to Log" --> A4
|
|
A0 -- "Applies Batches" --> A6
|
|
A0 -- "Triggers/Runs Compaction" --> A7
|
|
A1 -- "Provides Iterator" --> A5
|
|
A1 -- "Stores Keys Using" --> A8
|
|
A2 -- "Provides Iterator via Cache" --> A5
|
|
A3 -- "References SSTables" --> A2
|
|
A3 -- "Picks Files For" --> A7
|
|
A4 -- "Recovers MemTable From" --> A1
|
|
A4 -- "Contains Batch Data" --> A6
|
|
A5 -- "Parses/Hides InternalKey" --> A8
|
|
A6 -- "Inserts Into" --> A1
|
|
A7 -- "Builds SSTables" --> A2
|
|
A7 -- "Updates Versions Via Edit" --> A3
|
|
A7 -- "Uses Iterator for Merging" --> A5
|
|
``` |