# Advanced User Guide

## Additional Features

The main [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank} should be enough to give you a tour through all the main features of **FastAPI**.

In the next sections you will see other options, configurations, and additional features.

/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

  }

  /** Processes the available bytes of the buffer (at most {@code chunk} bytes). */
  protected abstract void process(ByteBuffer bb);

  /**
   * This is invoked for the last bytes of the input, which are not enough to fill a whole chunk.
   * The passed {@code ByteBuffer} is guaranteed to be non-empty.
   *
   * <p>This implementation simply pads with zeros and delegates to {@link #process(ByteBuffer)}.
   */

	SunOS)
		ARCH=$(isainfo -k)
		;;
	esac
}

## FIXME:
## In OSX, 'readlink -f' option does not exist, hence
## we have our own readlink -f behavior here.
## Once OSX has the option, below function is good enough.
##
## readlink() {
##     return /bin/readlink -f "$1"
## }
##
readlink() {
	TARGET_FILE=$1

	cd $(dirname $TARGET_FILE)
	TARGET_FILE=$(basename $TARGET_FILE)

package lock

import (
	"strings"
	"testing"
)

func TestFixLongPath(t *testing.T) {
	// 248 is long enough to trigger the longer-than-248 checks in
	// fixLongPath, but short enough not to make a path component
	// longer than 255, which is illegal on Windows. (which
	// doesn't really matter anyway, since this is purely a string

class Item(BaseModel):
    id: str
    value: str


responses = {
    404: {"description": "Item not found"},
    302: {"description": "The item was moved"},
    403: {"description": "Not enough privileges"},
}


app = FastAPI()


@app.get(
    "/items/{item_id}",
    response_model=Item,
    responses={**responses, 200: {"content": {"image/png": {}}}},
)

	// Offset and out size cannot be negative.
	if offset < 0 || length < 0 {
		return 0, errUnexpected
	}

	// Do we have enough blocks?
	if len(enBlocks) < dataBlocks {
		return 0, reedsolomon.ErrTooFewShards
	}

	// Do we have enough data?
	if int64(getDataBlockLen(enBlocks, dataBlocks)) < length {
		return 0, reedsolomon.ErrShortData
	}

	// Counter to decrement total left to write.

import java.io.File;

/**
 * Android-incompatible tests for {@link FileBackedOutputStream}.
 *
 * @author Chris Nokleberg
 */
@AndroidIncompatible // Finalization probably just doesn't happen fast enough?
public class FileBackedOutputStreamAndroidIncompatibleTest extends IoTestCase {

  public void testFinalizeDeletesFile() throws Exception {
    byte[] data = newPreFilledByteArray(100);

  }

  /** Processes the available bytes of the buffer (at most {@code chunk} bytes). */
  protected abstract void process(ByteBuffer bb);

  /**
   * This is invoked for the last bytes of the input, which are not enough to fill a whole chunk.
   * The passed {@code ByteBuffer} is guaranteed to be non-empty.
   *
   * <p>This implementation simply pads with zeros and delegates to {@link #process(ByteBuffer)}.
   */

-dontnote sun.misc.JavaLangAccess
-keep class sun.misc.JavaLangAccess {
  *** getStackTraceElement(...);
  *** getStackTraceDepth(...);
}

# FinalizableReferenceQueue calls this reflectively
# Proguard is intelligent enough to spot the use of reflection onto this, so we
# only need to keep the names, and allow it to be stripped out if
# FinalizableReferenceQueue is unused.
-keepnames class com.google.common.base.internal.Finalizer {

import java.io.File;

/**
 * Android-incompatible tests for {@link FileBackedOutputStream}.
 *
 * @author Chris Nokleberg
 */
@AndroidIncompatible // Finalization probably just doesn't happen fast enough?
public class FileBackedOutputStreamAndroidIncompatibleTest extends IoTestCase {

  public void testFinalizeDeletesFile() throws Exception {
    byte[] data = newPreFilledByteArray(100);