* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.
* Then it passes the **request** to be processed by the rest of the application (by some *path operation*).
* It then takes the **response** generated by the application (by some *path operation*).

* Decompressing gzip-compressed request bodies.
* Automatically logging all request bodies.

## Handling custom request body encodings { #handling-custom-request-body-encodings }

Let's see how to make use of a custom `Request` subclass to decompress gzip requests.

And an `APIRoute` subclass to use that custom request class.

### Create a custom `GzipRequest` class { #create-a-custom-gziprequest-class }

/// tip

# Dependencies - `Depends()` and `Security()`

## `Depends()`

Dependencies are handled mainly with the special function `Depends()` that takes a callable.

Here is the reference for it and its parameters.

You can import it directly from `fastapi`:

```python
from fastapi import Depends
```

::: fastapi.Depends

## `Security()`

	// Number of checksum info == total parts.
	xlMeta.Erasure.Checksums = make([]ChecksumInfo, totalParts)
	// total number of parts.
	xlMeta.Parts = make([]ObjectPartInfo, totalParts)
	for i := range totalParts {
		// hard coding hash and algo value for the checksum, Since we are benchmarking the parsing of xl.meta the magnitude doesn't affect the test,
		// The magnitude doesn't make a difference, only the size does.

# Form Data { #form-data }

When you need to receive form fields instead of JSON, you can use `Form`.

/// info

To use forms, first install [`python-multipart`](https://github.com/Kludex/python-multipart).

Make sure you create a [virtual environment](../virtual-environments.md), activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

## Import `Form` { #import-form }

- [ ] Write unit tests that match behavioral changes, where the tests fail if the changes to the runtime are not applied.
  This may not always be possible but is a best-practice.
- [ ] Run `mvn verify` to make sure basic checks pass.
  A more thorough check will be performed on your pull request automatically.
- [ ] You have run the [Core IT][core-its] successfully.

	f, err := OsOpenFile(name, readMode, 0o666)
	if err != nil {
		return nil, nil, err
	}
	defer f.Close()

	st, err := f.Stat()
	if err != nil {
		return nil, nil, err
	}

	dst := make([]byte, st.Size())
	_, err = io.ReadFull(f, dst)
	return dst, st, err
}

// ReadFile reads the named file and returns the contents.
// A successful call returns err == nil, not err == EOF.

			}
		case "MetaSys":
			var zb0002 uint32
			zb0002, err = dc.ReadMapHeader()
			if err != nil {
				err = msgp.WrapError(err, "MetaSys")
				return
			}
			if z.MetaSys == nil {
				z.MetaSys = make(map[string][]byte, zb0002)
			} else if len(z.MetaSys) > 0 {
				clear(z.MetaSys)
			}
			for zb0002 > 0 {
				zb0002--
				var za0002 string
				za0002, err = dc.ReadString()
				if err != nil {

	return sort.SliceIsSorted(m, m.less)
}

// shallowClone will create a shallow clone of the array objects,
// but object metadata will not be cloned.
func (m metaCacheEntries) shallowClone() metaCacheEntries {
	dst := make(metaCacheEntries, len(m))
	copy(dst, m)
	return dst
}

type metadataResolutionParams struct {
	dirQuorum int // Number if disks needed for a directory to 'exist'.

   */
  /*
   * TODO(cpovirk): or we could make HOLES_FORBIDDEN a feature. Or we could declare that
   * implementations are permitted to throw IAE if a hole is requested, and we could update
   * test*Hole to permit IAE. (But might this ignore genuine bugs?) But see the TODO above
   * testLower, which could make this all unnecessary
   */
  public static Method[] getHoleMethods() {