{* ../../docs_src/behind_a_proxy/tutorial002.py hl[3] *}

Passing the `root_path` to `FastAPI` would be the equivalent of passing the `--root-path` command line option to Uvicorn or Hypercorn.

### About `root_path`

Keep in mind that the server (Uvicorn) won't use that `root_path` for anything else than passing it to the app.

	}
}

// Tests validate bucket name.
func TestIsValidBucketName(t *testing.T) {
	testCases := []struct {
		bucketName string
		shouldPass bool
	}{
		// cases which should pass the test.
		// passing in valid bucket names.
		{"lol", true},
		{"1-this-is-valid", true},
		{"1-this-too-is-valid-1", true},
		{"this.works.too.1", true},
		{"1234567", true},
		{"123", true},

		if _, err := uuid.Parse(vid); err != nil {
			return opts, InvalidVersionID{
				Bucket:    bucket,
				Object:    object,
				VersionID: vid,
			}
		}
	}

	// default case of passing encryption headers to backend
	opts, err = getDefaultOpts(r.Header, false, nil)
	if err != nil {
		return opts, err
	}
	opts.PartNumber = partNumber
	opts.VersionID = vid

// directio.AlignSize is defined as 0 in MacOS causing divide by 0 error.
const DirectioAlignSize = 4096

// CopyAligned - copies from reader to writer using the aligned input
// buffer, it is expected that input buffer is page aligned to
// 4K page boundaries. Without passing aligned buffer may cause
// this function to return error.
//

current implementation may sometimes cause a runtime error if the
contents of the C memory appear to be a Go pointer. Therefore, avoid
passing uninitialized C memory to Go code if the Go code is going to
store pointer values in it. Zero out the memory in C before passing it
to Go.

# Optimizing calls of C code

When passing a Go pointer to a C function the compiler normally ensures
that the Go object lives on the heap. If the C function does not keep

But if you are certain that the content that you are returning is **serializable with JSON**, you can pass it directly to the response class and avoid the extra overhead that FastAPI would have by passing your return content through the `jsonable_encoder` before passing it to the response class.

```Python hl_lines="2  7"
{!../../docs_src/custom_response/tutorial001b.py!}
```

/// info

Every month, a GitHub Action updates the FastAPI People data. Those PRs look like this one: <a href="https://github.com/fastapi/fastapi/pull/11669" class="external-link" target="_blank">👥 Update FastAPI People</a>.

If the tests are passing, you can merge it right away.

## External Links PRs

		{ObjectOpts{}, cfgs[0], false},                                // 1. invalid ObjectOpts missing object name
		{ObjectOpts{Name: "c1test"}, cfgs[0], true},                   // 2. valid ObjectOpts passing empty Filter
		{ObjectOpts{Name: "c1test", VersionID: "vid"}, cfgs[0], true}, // 3. valid ObjectOpts passing empty Filter

Using `UploadFile` has several advantages over `bytes`:

* You don't have to use `File()` in the default value of the parameter.
* It uses a "spooled" file:
    * A file stored in memory up to a maximum size limit, and after passing this limit it will be stored in disk.
* This means that it will work well for large files like images, videos, large binaries, etc. without consuming all the memory.
* You can get metadata from the uploaded file.

```

### Existing object replication

Existing object replication as detailed [here](https://aws.amazon.com/blogs/storage/replicating-existing-objects-between-s3-buckets/) can be enabled by passing `existing-objects` as a value to `--replicate` flag while adding or editing a replication rule.