Struct LeaseConfig 

pub struct LeaseConfig {
    pub enabled: bool,
    pub interval_ms: u64,
    pub max_cleanup_duration_ms: u64,
}

Lease configuration for TTL-based key expiration

When enabled = true:

• Server initializes lease manager at startup
• Background worker periodically cleans expired keys
• Client TTL requests (ttl_secs > 0) are accepted

When enabled = false (default):

• No lease components initialized (zero overhead)
• Client TTL requests (ttl_secs > 0) are rejected with error
• All keys are permanent (ttl_secs = 0 is always allowed)

Performance

Background cleanup overhead: ~0.001% CPU

• Wakes up every interval_ms (default 1000ms)
• Scans expired keys (limited by max_cleanup_duration_ms)
• Deletes expired entries from storage

Examples

use d_engine_core::config::LeaseConfig;

// Default: disabled
let config = LeaseConfig::default();
assert!(!config.enabled);

// Enable with defaults
let config = LeaseConfig {
    enabled: true,
    ..Default::default()
};
assert_eq!(config.interval_ms, 1000);

Fields

enabled: bool

Enable TTL feature

• true: Initialize lease manager + start background cleanup worker
• false: No TTL support, reject requests with ttl_secs > 0

Default: false (zero overhead when TTL not needed)

interval_ms: u64

Background cleanup interval in milliseconds

How often the background worker wakes up to scan and delete expired keys.

Range: 100-3600000 (100ms to 1 hour) Default: 1000 (1 second)

Tuning guide:

• 1000ms (default): Balanced for most workloads
• 100-500ms: Aggressive cleanup for memory-sensitive apps
• 5000-10000ms: Relaxed cleanup for low TTL usage

Only used when enabled = true

max_cleanup_duration_ms: u64

Maximum cleanup duration per cycle (milliseconds)

Limits how long a single cleanup cycle can run to prevent excessive CPU usage in the background worker.

Range: 1-100ms Default: 1ms

Tuning guide:

• 1ms (default): Safe for latency-sensitive apps
• 5-10ms: Aggressive cleanup when backlog exists

• 10ms: Not recommended (can impact foreground operations)

Only used when enabled = true

Implementations

impl LeaseConfig

pub fn validate(&self) -> Result<()>

Validates configuration parameters

Returns error if:

• interval_ms is out of range (100-3600000)
• max_cleanup_duration_ms is out of range (1-100)

Trait Implementations

impl Clone for LeaseConfig

fn clone(&self) -> LeaseConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LeaseConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LeaseConfig

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for LeaseConfig

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for LeaseConfig

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.