# Configurações e Variáveis de Ambiente

Em muitos casos a sua aplicação pode precisar de configurações externas, como chaves secretas, credenciais de banco de dados, credenciais para serviços de email, etc.

A maioria dessas configurações é variável (podem mudar), como URLs de bancos de dados. E muitas delas podem conter dados sensíveis, como tokens secretos.

Por isso é comum prover essas configurações como variáveis de ambiente que são utilizidas pela aplicação.

i.push(b):j(b)),this},fire:function(){return k.fireWith(this,arguments),this},fired:function(){return!!c}};return k},n.extend({Deferred:function(a){var b=[["resolve","done",n.Callbacks("once memory"),"resolved"],["reject","fail",n.Callbacks("once memory"),"rejected"],["notify","progress",n.Callbacks("memory")]],c="pending",d={state:function(){return c},always:function(){return e.done(arguments).fail(arguments),this},then:function(){var a=arguments;return n.Deferred(function(c){n.each(b,function(b,f){var...

	ADDV16	$(8<<16), R4, R5	// ADDV16	$524288, R4, R5		// 85200010
	ADDV16	$(32767<<16), R4, R5	// ADDV16	$2147418112, R4, R5	// 85fcff11
	ADDV16	$(16<<16), R4		// ADDV16	$1048576, R4		// 84400010

	// Loong64 atomic memory access instructions
	AMSWAPB		R14, (R13), R12 // ac395c38
	AMSWAPH		R14, (R13), R12 // acb95c38
	AMSWAPW		R14, (R13), R12 // ac396038
	AMSWAPV		R14, (R13), R12 // acb96038
	AMCASB		R14, (R13), R12 // ac395838

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[21:22] hl[21:22] *}

### Create a Session Dependency { #create-a-session-dependency }

A **`Session`** is what stores the **objects in memory** and keeps track of any changes needed in the data, then it **uses the `engine`** to communicate with the database.

    assertThat((long) arraysDim1 * arraysDim2).isNotEqualTo((long) (arraysDim1 * arraysDim2));

    int[][] arrays = new int[arraysDim1][];
    // it's shared to avoid using too much memory in tests
    int[] sharedArray = new int[arraysDim2];
    Arrays.fill(arrays, sharedArray);

    try {
      Ints.concat(arrays);
      fail();
    } catch (IllegalArgumentException expected) {
    }

Pero en la mayoría de los casos en los que necesitamos hacer algo como esto, queremos que el modelo solo **filtre/elimine** algunos de los datos como en este ejemplo.

  }

  @VisibleForTesting
  @WeakOuter
  final class ValueSet extends Sets.ImprovedAbstractSet<V> {
    /*
     * We currently use a fixed load factor of 1.0, a bit higher than normal to reduce memory
     * consumption.
     */

    @ParametricNullness private final K key;
    @VisibleForTesting @Nullable ValueEntry<K, V>[] hashTable;
    private int size = 0;
    private int modCount = 0;

        }
        
        // Verify caching behavior
        assertTrue(file.canCacheWrite());
    }
}
```

## 9. Performance Considerations

### 9.1 Memory Management
- Lease entries should be evicted based on LRU when max leases reached
- Implement periodic cleanup of expired leases

### 9.2 Thread Safety
- Use concurrent data structures for lease storage

The `string()` method on response body is convenient and efficient for small documents. But if the response body is large (greater than 1 MiB), avoid `string()` because it will load the entire document into memory. In that case, prefer to process the body as a stream.

=== ":material-language-kotlin: Kotlin"
    ```kotlin
      private val client = OkHttpClient()

      fun run() {
        val request = Request.Builder()

   * list (counter-intuitive, but mathematically consistent).
   *
   * <p><i>Performance notes:</i> while the cartesian product of lists of size {@code m, n, p} is a
   * list of size {@code m x n x p}, its actual memory consumption is much smaller. When the
   * cartesian product is constructed, the input lists are merely copied. Only as the resulting list
   * is iterated are the individual lists created, and these are not retained after iteration.