Struct SchemaCache 

pub struct SchemaCache { /* private fields */ }

A thread-safe cache for normalized JSON Schemas.

Stores normalized schemas keyed by a 64-bit hash of the serialized input schema. This avoids re-running normalization transforms on unchanged schemas across repeated generate_content() calls.

Thread Safety

Uses std::sync::Mutex internally, making it safe to share across threads. The lock is held only briefly during hash lookup and insertion.

Placement

Intended to live on model instances so each provider adapter maintains its own cache of normalized schemas.

Implementations

impl SchemaCache

pub fn new() -> Self

Creates a new empty schema cache.

Example

use adk_core::SchemaCache;

let cache = SchemaCache::new();

pub fn get_or_normalize( &self, schema: &Value, adapter: &dyn SchemaAdapter, ) -> Value

Returns the normalized schema for the given input, using the cache if available.

If the schema has been normalized before (based on content hash), the cached result is returned. Otherwise, adapter.normalize_schema() is called and the result is stored in the cache.

Arguments

• schema - The raw JSON Schema to normalize.
• adapter - The provider-specific schema adapter to use for normalization.

Returns

The normalized JSON Schema value.

Example

use adk_core::{SchemaCache, SchemaAdapter, GenericSchemaAdapter};
use serde_json::json;

let cache = SchemaCache::new();
let adapter = GenericSchemaAdapter;
let schema = json!({"$schema": "draft-07", "type": "string"});

let normalized = cache.get_or_normalize(&schema, &adapter);
assert!(normalized.get("$schema").is_none());

pub fn clear(&self)

Clears all cached entries.

Call this when the set of tools changes (e.g., MCP server advertises updated schemas) to force re-normalization on the next request.

Example

use adk_core::{SchemaCache, GenericSchemaAdapter};
use serde_json::json;

let cache = SchemaCache::new();
let adapter = GenericSchemaAdapter;
let schema = json!({"type": "string"});

// Populate cache
cache.get_or_normalize(&schema, &adapter);

// Invalidate all entries
cache.clear();

pub fn len(&self) -> usize

Returns the number of cached entries.

pub fn is_empty(&self) -> bool

Returns true if the cache contains no entries.

Trait Implementations

impl Debug for SchemaCache

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

Formats the value using the given formatter.

impl Default for SchemaCache

fn default() -> SchemaCache

Returns the “default value” for a type.