byte[] enc = constant;
        int klen = keybytes.length;
        byte[] dk = new byte[klen];
        for (int n = 0; n < klen;) {
            byte[] block = cipher.doFinal(enc);
            int len = Math.min(klen - n, block.length);
            System.arraycopy(block, 0, dk, n, len);
            n += len;
            enc = block;
        }
        return dk;
    }

    /**

        shareInfo502.type = 1;
        shareInfo502.remark = "Test Remark";
        shareInfo502.permissions = 2;
        shareInfo502.max_uses = 10;
        shareInfo502.current_uses = 5;
        shareInfo502.path = "C:\\test";
        shareInfo502.password = "password";
        shareInfo502.sd_size = 2;
        shareInfo502.security_descriptor = new byte[] { 1, 2 };

        // Set up mocks for the security descriptor encoding

{* ../../docs_src/request_files/tutorial001_an_py310.py hl[9] *}

/// info | Informação

`File` é uma classe que herda diretamente de `Form`.

Mas lembre-se que quando você importa `Query`, `Path`, `File` e outros de `fastapi`, eles são, na verdade, funções que retornam classes especiais.

///

/// tip | Dica

import static com.google.common.base.Preconditions.checkState;
import static com.google.common.collect.CollectPreconditions.checkRemove;
import static java.lang.Math.max;
import static java.lang.Math.min;
import static java.lang.System.arraycopy;
import static java.util.Objects.requireNonNull;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.J2ktIncompatible;

    assertThat(responseCookies.size).isEqualTo(2)
    assertThat(responseCookies[0].toString())
      .isEqualTo("a=b; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/")
    assertThat(responseCookies[1].toString())
      .isEqualTo("c=d; expires=Fri, 02 Jan 1970 23:59:59 GMT; path=/bar; secure")
  }

  @Test
  fun requestCookies() {
    server.enqueue(MockResponse())
    val cookieJar = RecordingCookieJar()

        MessageDigest md5 = MessageDigest.getInstance("MD5");
        byte[] ipad = new byte[64];
        byte[] opad = new byte[64];

        // HMACT64 specific: truncate key to 64 bytes if needed
        int keyLen = Math.min(key.length, 64);
        for (int i = 0; i < keyLen; i++) {
            ipad[i] = (byte) (key[i] ^ 0x36);
            opad[i] = (byte) (key[i] ^ 0x5c);
        }
        for (int i = keyLen; i < 64; i++) {

{* ../../docs_src/stream_data/tutorial001_py310.py ln[1:23] hl[20,23] *}

FastAPI 會如實將每個資料區塊交給 `StreamingResponse`，不會嘗試將其轉換為 JSON 或其他格式。

### 非 async 路徑操作函式 { #non-async-path-operation-functions }

你也可以使用一般的 `def` 函式（沒有 `async`），並以相同方式使用 `yield`。

{* ../../docs_src/stream_data/tutorial001_py310.py ln[26:29] hl[27] *}

### 不需要型別註解 { #no-annotation }

對於串流二進位資料，其實不需要宣告回傳型別註解。

```

那麼你應該把 `entrypoint` 設為：

```toml
[tool.fastapi]
entrypoint = "backend.main:app"
```

這等同於：

```python
from backend.main import app
```

### 帶路徑的 `fastapi dev` { #fastapi-dev-with-path }

你也可以把檔案路徑傳給 `fastapi dev` 指令，它會推測要使用的 FastAPI app 物件：

```console
$ fastapi dev main.py
```

但這樣每次呼叫 `fastapi` 指令時都得記得傳入正確的路徑。

不必为你使用的所有标签都添加元数据。

///

### 使用你的标签 { #use-your-tags }

将 `tags` 参数和*路径操作*（以及 `APIRouter`）一起使用，将其分配给不同的标签：

{* ../../docs_src/metadata/tutorial004_py310.py hl[21,26] *}

/// info | 信息

阅读更多关于标签的信息[路径操作配置](path-operation-configuration.md#tags)。

///

### 查看文档 { #check-the-docs }

如果你现在查看文档，它们会显示所有附加的元数据：

<img src="/img/tutorial/metadata/image02.png">

### 标签顺序 { #order-of-tags }

                region.getBuffer().clear();
                return region;
            }
        }

        // Allocate new buffer
        ByteBuffer buffer = ByteBuffer.allocateDirect(Math.max(minSize, sendBufferSize));
        RdmaMemoryRegion region = provider.registerMemory(buffer, EnumSet.of(RdmaAccess.LOCAL_READ, RdmaAccess.REMOTE_READ));
        totalAllocated.incrementAndGet();
        return region;