Struct QueryResultCache 

pub struct QueryResultCache { /* private fields */ }

Thread-safe W-TinyLFU cache for query results.

Backed by moka::sync::Cache which provides lock-free reads via Concurrent TinyLFU. Reverse DashMap indexes enable O(k) invalidation.

Thread Safety

moka::sync::Cache is Send + Sync. All reverse indexes use DashMap (fine-grained shard locking) and DashSet (also shard-locked). There is no global mutex on the read path.

Example

use fraiseql_core::cache::{QueryResultCache, CacheConfig};
use fraiseql_core::db::types::JsonbValue;
use serde_json::json;

let cache = QueryResultCache::new(CacheConfig::default());

// Cache a result
let result = vec![JsonbValue::new(json!({"id": 1, "name": "Alice"}))];
cache.put(
    12345_u64,
    result.clone(),
    vec!["v_user".to_string()],
    None, // use global TTL
    None, // no entity type index
).unwrap();

// Retrieve from cache
if let Some(cached) = cache.get(12345).unwrap() {
    println!("Cache hit! {} results", cached.len());
}

Implementations

impl QueryResultCache

pub fn new(config: CacheConfig) -> Self

Create new cache with configuration.

Panics

Panics if config.max_entries is 0 (invalid configuration).

Example

use fraiseql_core::cache::{QueryResultCache, CacheConfig};

let cache = QueryResultCache::new(CacheConfig::default());

pub const fn is_enabled(&self) -> bool

Returns whether caching is enabled.

Used by CachedDatabaseAdapter to short-circuit key generation and result clone overhead when caching is disabled.

pub fn get(&self, cache_key: u64) -> Result<Option<Arc<Vec<JsonbValue>>>>

Look up a cached result by its cache key.

Returns None when caching is disabled or the key is not present or expired. Moka handles TTL expiry internally — if get() returns Some, the entry is live.

Errors

This method is infallible. The Result return type is kept for API compatibility.

pub fn put_arc( &self, cache_key: u64, result: Arc<Vec<JsonbValue>>, accessed_views: Vec<String>, ttl_override: Option<u64>, entity_type: Option<&str>, ) -> Result<()>

Store query result in cache, accepting an already-Arc-wrapped result.

Preferred over put on the hot miss path: callers that already hold an Arc<Vec<JsonbValue>> (e.g. CachedDatabaseAdapter) can store it without an extra Vec clone.

Arguments

• cache_key - Cache key (from generate_cache_key())
• result - Arc-wrapped query result to cache
• accessed_views - List of views accessed by this query
• ttl_override - Per-entry TTL in seconds; None uses CacheConfig::ttl_seconds
• entity_type - Optional GraphQL type name for entity-ID indexing

Errors

This method is infallible. The Result return type is kept for API compatibility.

pub fn put( &self, cache_key: u64, result: Vec<JsonbValue>, accessed_views: Vec<String>, ttl_override: Option<u64>, entity_type: Option<&str>, ) -> Result<()>

Store query result in cache.

If caching is disabled, this is a no-op.

Wraps result in an Arc and delegates to put_arc. Prefer put_arc when the caller already holds an Arc.

Arguments

• cache_key - Cache key (from generate_cache_key())
• result - Query result to cache
• accessed_views - List of views accessed by this query
• ttl_override - Per-entry TTL in seconds; None uses CacheConfig::ttl_seconds
• entity_type - Optional GraphQL type name (e.g. "User") for entity-ID indexing. When provided, each row’s "id" field is extracted and stored in entity_index so that invalidate_by_entity() can perform selective eviction.

Errors

This method is infallible. The Result return type is kept for API compatibility.

Example

use fraiseql_core::cache::{QueryResultCache, CacheConfig};
use fraiseql_core::db::types::JsonbValue;
use serde_json::json;

let cache = QueryResultCache::new(CacheConfig::default());

let result = vec![JsonbValue::new(json!({"id": "uuid-1"}))];
cache.put(0xabc123, result, vec!["v_user".to_string()], None, Some("User"))?;

pub fn invalidate_views(&self, views: &[ViewName]) -> Result<u64>

Invalidate entries accessing specified views.

Uses the view_index for O(k) lookup instead of O(n) full-cache scan. Keys accessing multiple views in views are deduplicated before invalidation.

Arguments

• views - List of view/table names modified by mutation

Returns

Number of cache entries invalidated.

Errors

This method is infallible. The Result return type is kept for API compatibility.

Example

use fraiseql_core::cache::{QueryResultCache, CacheConfig};
use fraiseql_db::ViewName;

let cache = QueryResultCache::new(CacheConfig::default());

// After createUser mutation
let invalidated = cache.invalidate_views(&[ViewName::from("v_user")])?;
println!("Invalidated {} cache entries", invalidated);

pub fn invalidate_list_queries(&self, views: &[ViewName]) -> Result<u64>

Evict only list (multi-row) cache entries for the given views.

Unlike invalidate_views(), this method leaves single-entity point-lookup entries intact. Used for CREATE mutations: creating a new entity does not affect queries that fetch a different existing entity by UUID, but it does invalidate queries that return a variable-length list of entities.

Uses the list_index for O(k) lookup.

Errors

This method is infallible. The Result return type is kept for API compatibility.

pub fn invalidate_by_entity( &self, entity_type: &str, entity_id: &str, ) -> Result<u64>

Evict cache entries that contain a specific entity UUID.

Uses the entity_index for O(k) lookup. Entries not referencing this entity are left untouched.

Arguments

• entity_type - GraphQL type name (e.g. "User")
• entity_id - UUID string of the mutated entity

Returns

Number of cache entries evicted.

Errors

This method is infallible. The Result return type is kept for API compatibility.

pub fn metrics(&self) -> Result<CacheMetrics>

Get cache metrics snapshot.

Returns a consistent snapshot of current counters. Individual fields may be updated independently (atomics), so the snapshot is not a single atomic transaction, but is accurate enough for monitoring.

Errors

This method is infallible. The Result return type is kept for API compatibility.

Example

use fraiseql_core::cache::{QueryResultCache, CacheConfig};

let cache = QueryResultCache::new(CacheConfig::default());
let metrics = cache.metrics()?;

println!("Hit rate: {:.1}%", metrics.hit_rate() * 100.0);
println!("Size: {} / {} entries", metrics.size, 10_000);

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

Clear all cache entries.

Resets the store, reverse indexes, and memory_bytes synchronously. The eviction listener will still fire asynchronously for each evicted entry, but its index-cleanup operations will be no-ops on the already-cleared maps.

Errors

This method is infallible. The Result return type is kept for API compatibility.

Example

use fraiseql_core::cache::{QueryResultCache, CacheConfig};

let cache = QueryResultCache::new(CacheConfig::default());
cache.clear()?;