main.go

main.go - Overview

This file defines the ShardThread struct and its associated methods for managing a shard within the DiceDB system. It handles the lifecycle of a shard, including initialization, periodic tasks (cron), and cleanup.

Detailed Documentation

ShardThread

type ShardThread struct {
	id               int           // id is the unique identifier for the shard.
	store            *dstore.Store // store that the shard is responsible for.
	globalErrorChan  chan error    // globalErrorChan is the channel for sending system-level errors.
	lastCronExecTime time.Time     // lastCronExecTime is the last time the shard executed cron tasks.
	cronFrequency    time.Duration // cronFrequency is the frequency at which the shard executes cron tasks.
}

• Purpose: Represents a shard within the DiceDB system, responsible for managing a portion of the data.
• Fields:
  • id: The unique identifier for the shard (int).
  • store: The dstore.Store instance that the shard manages (*dstore.Store).
  • globalErrorChan: A channel for sending system-level errors (chan error).
  • lastCronExecTime: The last time the shard executed cron tasks (time.Time).
  • cronFrequency: The frequency at which the shard executes cron tasks (time.Duration).

NewShardThread

func NewShardThread(id int, gec chan error, evictionStrategy dstore.EvictionStrategy) *ShardThread

• Purpose: Creates a new ShardThread instance.
• Parameters:
  • id: The ID of the shard (int).
  • gec: The global error channel (chan error).
  • evictionStrategy: The eviction strategy for the store (dstore.EvictionStrategy).
• Returns: A pointer to the newly created ShardThread instance (*ShardThread).

Start

func (shard *ShardThread) Start(ctx context.Context)

• Purpose: Starts the shard thread, listening for incoming requests and executing cron tasks.
• Parameters:
  • ctx: A context.Context for managing the shard's lifecycle.
• Returns: None.

runCronTasks

func (shard *ShardThread) runCronTasks()

• Purpose: Executes the cron tasks for the shard, including deleting expired keys.
• Parameters: None.
• Returns: None.

cleanup

func (shard *ShardThread) cleanup()

• Purpose: Handles cleanup logic when the shard stops, such as WAL flushing.
• Parameters: None.
• Returns: None.

Store

func (shard *ShardThread) Store() *dstore.Store

• Purpose: Returns the dstore.Store associated with the shard.
• Parameters: None.
• Returns: A pointer to the dstore.Store (*dstore.Store).

Code Examples

None.

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