Struct SqlTemplateCache 

pub struct SqlTemplateCache { /* private fields */ }

A high-performance SQL template cache optimized for repeated queries.

Unlike QueryCache which stores full SQL strings, SqlTemplateCache stores template structures with pre-computed placeholder positions for very fast instantiation.

Performance

• Cache lookup: O(1) hash lookup, ~5-10ns
• Template instantiation: O(n) where n is parameter count
• Thread-safe with minimal contention (parking_lot RwLock)

Examples

use prax_query::cache::SqlTemplateCache;

let cache = SqlTemplateCache::new(1000);

// Register a template
let template = cache.register("users_by_id", "SELECT * FROM users WHERE id = $1");

// Instant retrieval (~5ns)
let sql = cache.get("users_by_id");

Implementations

impl SqlTemplateCache

pub fn new(max_size: usize) -> Self

Create a new template cache with the given maximum size.

pub fn register( &self, key: impl Into<Cow<'static, str>>, sql: impl AsRef<str>, ) -> Arc<SqlTemplate>

Register a SQL template with a string key.

Returns the template for immediate use.

pub fn register_by_hash( &self, hash: u64, sql: impl AsRef<str>, ) -> Arc<SqlTemplate>

Register a template by hash (for pre-computed hashes).

pub fn get(&self, key: &str) -> Option<Arc<SqlTemplate>>

Get a template by string key (returns Arc for zero-copy).

Performance

This is the fastest way to get cached SQL:

• Hash lookup: ~5ns
• Returns Arc (no allocation)

pub fn get_by_hash(&self, hash: u64) -> Option<Arc<SqlTemplate>>

Get a template by pre-computed hash (fastest path).

Performance

~3-5ns for cache hit with pre-computed hash.

pub fn get_sql(&self, key: &str) -> Option<Arc<str>>

Get the SQL string directly (convenience method).

pub fn get_or_register<F>( &self, key: impl Into<Cow<'static, str>>, f: F, ) -> Arc<SqlTemplate>

where F: FnOnce() -> String,

Get or compute a template.

pub fn contains(&self, key: &str) -> bool

Check if a key exists.

pub fn stats(&self) -> CacheStats

Get cache statistics.

pub fn len(&self) -> usize

Get the number of cached templates.

pub fn is_empty(&self) -> bool

Check if the cache is empty.

pub fn clear(&self)

Clear the cache.

Trait Implementations

impl Debug for SqlTemplateCache

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

Formats the value using the given formatter.

impl Default for SqlTemplateCache

fn default() -> Self

Returns the “default value” for a type.