tikv/tikv

Align key memory location

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#3486 opened on Aug 20, 2018

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 (1 comment) (0 reactions) (0 assignees)Rust (15,922 stars) (2,189 forks)batch import
component/performancedifficulty/mediumhelp wanted

Description

Feature Request

After encoding, our keys are 9*N in length (or 9*N+8 if it has timestamp suffix).

when comparing key equality, or decoding key timestamp, we access its last 8*N part, which is not memory aligned in most cases. Make keys ends with a memory aligned location could improve performance.

Contributor guide

Tech stack
rust
Domain
performance
Issue type
performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Understanding of Rust memory layoutFamiliarity with TikV key encoding
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Investigate the key encoding functions in the storage module, likely in the `src/storage` or `src/coprocessor` directories. Examine how keys are currently constructed and where alignment is broken. Look for comments or discussions in the issue thread, especially the single comment, for any additional context or suggestions from maintainers. Consider reading related code for key comparison and timestamp decoding to understand the current memory access patterns.