Function generate_cache_key 

pub fn generate_cache_key(
    query: &str,
    variables: &Value,
    where_clause: Option<&WhereClause>,
    schema_version: &str,
) -> u64

Generate cache key for query result.

Security Critical

DIFFERENT VARIABLE VALUES MUST PRODUCE DIFFERENT KEYS to prevent data leakage between users. This function feeds the full query, variables, WHERE clause, and schema version into a single-pass ahash for a fast, deterministic u64 key.

Key Composition

The cache key is a single ahash pass over:

ahash(
  query_bytes          +
  hash(variables)      +   ← recursive, canonical key ordering
  hash(WHERE_clause)   +   ← structural, not serde-dependent
  schema_version_bytes
)

This ensures:

• Same query + variables = same key (cache hit)
• Different variables = different key (security)
• Different WHERE clauses = different key (correctness)
• Schema changes = different key (validity)

Arguments

• query - GraphQL query string
• variables - Query variables from GraphQL request (optional)
• where_clause - WHERE filter from auto-params (optional)
• schema_version - Schema hash from CompiledSchema

Returns

A u64 cache key suitable for use as a hash-map key.

Security Examples

use fraiseql_core::cache::generate_cache_key;
use serde_json::json;

let query = "query getUser($id: ID!) { user(id: $id) { name } }";

// Different users MUST get different cache keys
let alice_key = generate_cache_key(query, &json!({"id": "alice"}), None, "v1");
let bob_key = generate_cache_key(query, &json!({"id": "bob"}), None, "v1");
assert_ne!(alice_key, bob_key, "Security: different variables must produce different keys");

// Same user MUST get same key (determinism)
let alice_key2 = generate_cache_key(query, &json!({"id": "alice"}), None, "v1");
assert_eq!(alice_key, alice_key2, "Determinism: same inputs must produce same key");