Method test

test/IECore/ComputationCacheTest.cpp:73–166

	}

	void test()
	{
		ConstObjectPtr res;
		IntDataPtr v = new IntData(1);

		/// limit the pool to fit only one integer.
		ObjectPoolPtr pool = new ObjectPool( v->Object::memoryUsage() );

		Cache cache( get, hash, 1000, pool );

		BOOST_CHECK_EQUAL( pool.get(), cache.objectPool() );

		BOOST_CHECK_EQUAL( size_t(1000), cache.getMaxComputations() );
		cache.setMaxComputations( 100 );
		BOOST_CHECK_EQUAL( size_t(100), cache.getMaxComputations() );
		BOOST_CHECK_EQUAL( size_t(0), cache.cachedComputations() );

		/// cache should return NULL on never computed values (hash is unknown)
		res = cache.get( ComputationParams(2), Cache::NullIfMissing );
		BOOST_CHECK( !res );
		// this is weird, but because we are using LRUCache with a dummie and we don't
		/// want to do two queries, it ends up registering that computation with the default hash...
		BOOST_CHECK_EQUAL( size_t(1), cache.cachedComputations() );

		/// computes a value (default value)
		res = cache.get( ComputationParams(2) );
		BOOST_CHECK( res );
		BOOST_CHECK_EQUAL( size_t(1), cache.cachedComputations() );

		/// computes a value (explicit)
		res = cache.get( ComputationParams(3), Cache::ComputeIfMissing );
		BOOST_CHECK( res );
		BOOST_CHECK_EQUAL( size_t(2), cache.cachedComputations() );

		/// Cache should have evicted one value due to the memory limit
		/// of the ObjectPool.
		ConstObjectPtr res2 = cache.get( ComputationParams( 2 ), Cache::NullIfMissing );
		ConstObjectPtr res3 = cache.get( ComputationParams( 3 ), Cache::NullIfMissing );
		BOOST_CHECK( !(res2 && res3) );
		BOOST_CHECK( res2 || res3 );

		/// now increase memory limit to two IntData objects
		pool->setMaxMemoryUsage( v->Object::memoryUsage() * 2 );

		/// computes two new values
		cache.get( ComputationParams(4) );
		cache.get( ComputationParams(5) );
		BOOST_CHECK_EQUAL( size_t(4), cache.cachedComputations() );
		res2 = cache.get( ComputationParams( 2 ), Cache::NullIfMissing );
		res3 = cache.get( ComputationParams( 3 ), Cache::NullIfMissing );
		ConstObjectPtr res4 = cache.get( ComputationParams( 4 ), Cache::NullIfMissing );
		ConstObjectPtr res5 = cache.get( ComputationParams( 5 ), Cache::NullIfMissing );
		/// Cache should have two values present, two missing
		BOOST_CHECK_EQUAL( (int)!res2 + (int)!res3 + (int)!res4 + (int)!res5, 2 );

		/// clears the all values
		cache.clear();
		pool->clear();