route_utils.py

from __future__ import annotations

import hashlib
import hmac
import json
import shutil
from collections import deque
from dataclasses import dataclass as python_dataclass
from tempfile import NamedTemporaryFile, _TemporaryFileWrapper
from typing import TYPE_CHECKING, AsyncGenerator, BinaryIO, List, Optional, Tuple, Union

import fastapi
import httpx
import multipart
from gradio_client.documentation import document
from multipart.multipart import parse_options_header
from starlette.datastructures import FormData, Headers, UploadFile
from starlette.formparsers import MultiPartException, MultipartPart

from gradio import processing_utils, utils
from gradio.data_classes import PredictBody
from gradio.exceptions import Error
from gradio.helpers import EventData
from gradio.state_holder import SessionState

if TYPE_CHECKING:
    from gradio.blocks import Blocks
    from gradio.routes import App


class Obj:
    """
    Using a class to convert dictionaries into objects. Used by the `Request` class.
    Credit: https://www.geeksforgeeks.org/convert-nested-python-dictionary-to-object/
    """

    def __init__(self, dict_):
        self.__dict__.update(dict_)
        for key, value in dict_.items():
            if isinstance(value, (dict, list)):
                value = Obj(value)
            setattr(self, key, value)

    def __getitem__(self, item):
        return self.__dict__[item]

    def __setitem__(self, item, value):
        self.__dict__[item] = value

    def __iter__(self):
        for key, value in self.__dict__.items():
            if isinstance(value, Obj):
                yield (key, dict(value))
            else:
                yield (key, value)

    def __contains__(self, item) -> bool:
        if item in self.__dict__:
            return True
        for value in self.__dict__.values():
            if isinstance(value, Obj) and item in value:
                return True
        return False

    def keys(self):
        return self.__dict__.keys()

    def values(self):
        return self.__dict__.values()

    def items(self):
        return self.__dict__.items()

    def __str__(self) -> str:
        return str(self.__dict__)

    def __repr__(self) -> str:
        return str(self.__dict__)


@document()
class Request:
    """
    A Gradio request object that can be used to access the request headers, cookies,
    query parameters and other information about the request from within the prediction
    function. The class is a thin wrapper around the fastapi.Request class. Attributes
    of this class include: `headers`, `client`, `query_params`, and `path_params`. If
    auth is enabled, the `username` attribute can be used to get the logged in user.
    Example:
        import gradio as gr
        def echo(text, request: gr.Request):
            if request:
                print("Request headers dictionary:", request.headers)
                print("IP address:", request.client.host)
                print("Query parameters:", dict(request.query_params))
            return text
        io = gr.Interface(echo, "textbox", "textbox").launch()
    Demos: request_ip_headers
    """

    def __init__(
        self,
        request: fastapi.Request | None = None,
        username: str | None = None,
        **kwargs,
    ):
        """
        Can be instantiated with either a fastapi.Request or by manually passing in
        attributes (needed for queueing).
        Parameters:
            request: A fastapi.Request
        """
        self.request = request
        self.username = username
        self.kwargs: dict = kwargs

    def dict_to_obj(self, d):
        if isinstance(d, dict):
            return json.loads(json.dumps(d), object_hook=Obj)
        else:
            return d

    def __getattr__(self, name):
        if self.request:
            return self.dict_to_obj(getattr(self.request, name))
        else:
            try:
                obj = self.kwargs[name]
            except KeyError as ke:
                raise AttributeError(
                    f"'Request' object has no attribute '{name}'"
                ) from ke
            return self.dict_to_obj(obj)


class FnIndexInferError(Exception):
    pass


def infer_fn_index(app: App, api_name: str, body: PredictBody) -> int:
    if body.fn_index is None:
        for i, fn in enumerate(app.get_blocks().dependencies):
            if fn["api_name"] == api_name:
                return i

        raise FnIndexInferError(f"Could not infer fn_index for api_name {api_name}.")
    else:
        return body.fn_index


def compile_gr_request(
    app: App,
    body: PredictBody,
    fn_index_inferred: int,
    username: Optional[str],
    request: Optional[fastapi.Request],
):
    # If this fn_index cancels jobs, then the only input we need is the
    # current session hash
    if app.get_blocks().dependencies[fn_index_inferred]["cancels"]:
        body.data = [body.session_hash]
    if body.request:
        if body.batched:
            gr_request = [Request(username=username, request=request)]
        else:
            gr_request = Request(username=username, request=body.request)
    else:
        if request is None:
            raise ValueError("request must be provided if body.request is None")
        gr_request = Request(username=username, request=request)

    return gr_request


def restore_session_state(app: App, body: PredictBody):
    event_id = body.event_id
    session_hash = getattr(body, "session_hash", None)
    if session_hash is not None:
        session_state = app.state_holder[session_hash]
        # The should_reset set keeps track of the fn_indices
        # that have been cancelled. When a job is cancelled,
        # the /reset route will mark the jobs as having been reset.
        # That way if the cancel job finishes BEFORE the job being cancelled
        # the job being cancelled will not overwrite the state of the iterator.
        if event_id is None:
            iterator = None
        elif event_id in app.iterators_to_reset:
            iterator = None
            app.iterators_to_reset.remove(event_id)
        else:
            iterator = app.iterators.get(event_id)
    else:
        session_state = SessionState(app.get_blocks())
        iterator = None

    return session_state, iterator


def prepare_event_data(
    blocks: Blocks,
    body: PredictBody,
) -> EventData:
    target = body.trigger_id
    event_data = EventData(
        blocks.blocks.get(target) if target else None,
        body.event_data,
    )
    return event_data


async def call_process_api(
    app: App,
    body: PredictBody,
    gr_request: Union[Request, list[Request]],
    fn_index_inferred: int,
):
    session_state, iterator = restore_session_state(app=app, body=body)

    dependency = app.get_blocks().dependencies[fn_index_inferred]
    event_data = prepare_event_data(app.get_blocks(), body)
    event_id = body.event_id

    session_hash = getattr(body, "session_hash", None)
    inputs = body.data

    batch_in_single_out = not body.batched and dependency["batch"]
    if batch_in_single_out:
        inputs = [inputs]

    try:
        with utils.MatplotlibBackendMananger():
            output = await app.get_blocks().process_api(
                fn_index=fn_index_inferred,
                inputs=inputs,
                request=gr_request,
                state=session_state,
                iterator=iterator,
                session_hash=session_hash,
                event_id=event_id,
                event_data=event_data,
                in_event_listener=True,
            )
        iterator = output.pop("iterator", None)
        if event_id is not None:
            app.iterators[event_id] = iterator  # type: ignore
        if isinstance(output, Error):
            raise output
    except BaseException:
        iterator = app.iterators.get(event_id) if event_id is not None else None
        if iterator is not None:  # close off any streams that are still open
            run_id = id(iterator)
            pending_streams: dict[int, list] = (
                app.get_blocks().pending_streams[session_hash].get(run_id, {})
            )
            for stream in pending_streams.values():
                stream.append(None)
        raise

    if batch_in_single_out:
        output["data"] = output["data"][0]

    return output


def get_root_url(
    request: fastapi.Request, route_path: str, root_path: str | None
) -> str:
    """
    Gets the root url of the request, stripping off any query parameters, the route_path, and trailing slashes.
    Also ensures that the root url is https if the request is https. If root_path is provided, it is appended to the root url.
    The final root url will not have a trailing slash.
    """
    root_url = str(request.url)
    root_url = httpx.URL(root_url)
    root_url = root_url.copy_with(query=None)
    root_url = str(root_url).rstrip("/")
    if request.headers.get("x-forwarded-proto") == "https":
        root_url = root_url.replace("http://", "https://")
    route_path = route_path.rstrip("/")
    if len(route_path) > 0:
        root_url = root_url[: -len(route_path)]
    return (root_url.rstrip("/") + (root_path or "")).rstrip("/")


def _user_safe_decode(src: bytes, codec: str) -> str:
    try:
        return src.decode(codec)
    except (UnicodeDecodeError, LookupError):
        return src.decode("latin-1")


class GradioUploadFile(UploadFile):
    """UploadFile with a sha attribute."""

    def __init__(
        self,
        file: BinaryIO,
        *,
        size: int | None = None,
        filename: str | None = None,
        headers: Headers | None = None,
    ) -> None:
        super().__init__(file, size=size, filename=filename, headers=headers)
        self.sha = hashlib.sha1()


@python_dataclass(frozen=True)
class FileUploadProgressUnit:
    filename: str
    chunk_size: int


@python_dataclass
class FileUploadProgressTracker:
    deque: deque[FileUploadProgressUnit]
    is_done: bool


class FileUploadProgressNotTrackedError(Exception):
    pass


class FileUploadProgressNotQueuedError(Exception):
    pass


class FileUploadProgress:
    def __init__(self) -> None:
        self._statuses: dict[str, FileUploadProgressTracker] = {}

    def track(self, upload_id: str):
        if upload_id not in self._statuses:
            self._statuses[upload_id] = FileUploadProgressTracker(deque(), False)

    def append(self, upload_id: str, filename: str, message_bytes: bytes):
        if upload_id not in self._statuses:
            self.track(upload_id)
        queue = self._statuses[upload_id].deque

        if len(queue) == 0:
            queue.append(FileUploadProgressUnit(filename, len(message_bytes)))
        else:
            last_unit = queue.popleft()
            if last_unit.filename != filename:
                queue.append(FileUploadProgressUnit(filename, len(message_bytes)))
            else:
                queue.append(
                    FileUploadProgressUnit(
                        filename,
                        last_unit.chunk_size + len(message_bytes),
                    )
                )

    def set_done(self, upload_id: str):
        if upload_id not in self._statuses:
            self.track(upload_id)
        self._statuses[upload_id].is_done = True

    def is_done(self, upload_id: str):
        if upload_id not in self._statuses:
            raise FileUploadProgressNotTrackedError()
        return self._statuses[upload_id].is_done

    def stop_tracking(self, upload_id: str):
        if upload_id in self._statuses:
            del self._statuses[upload_id]

    def pop(self, upload_id: str) -> FileUploadProgressUnit:
        if upload_id not in self._statuses:
            raise FileUploadProgressNotTrackedError()
        try:
            return self._statuses[upload_id].deque.pop()
        except IndexError as e:
            raise FileUploadProgressNotQueuedError() from e


class GradioMultiPartParser:
    """Vendored from starlette.MultipartParser.

    Thanks starlette!

    Made the following modifications
        - Use GradioUploadFile instead of UploadFile
        - Use NamedTemporaryFile instead of SpooledTemporaryFile
        - Compute hash of data as the request is streamed

    """

    max_file_size = 1024 * 1024

    def __init__(
        self,
        headers: Headers,
        stream: AsyncGenerator[bytes, None],
        *,
        max_files: Union[int, float] = 1000,
        max_fields: Union[int, float] = 1000,
        upload_id: str | None = None,
        upload_progress: FileUploadProgress | None = None,
    ) -> None:
        assert (
            multipart is not None
        ), "The `python-multipart` library must be installed to use form parsing."
        self.headers = headers
        self.stream = stream
        self.max_files = max_files
        self.max_fields = max_fields
        self.items: List[Tuple[str, Union[str, UploadFile]]] = []
        self.upload_id = upload_id
        self.upload_progress = upload_progress
        self._current_files = 0
        self._current_fields = 0
        self._current_partial_header_name: bytes = b""
        self._current_partial_header_value: bytes = b""
        self._current_part = MultipartPart()
        self._charset = ""
        self._file_parts_to_write: List[Tuple[MultipartPart, bytes]] = []
        self._file_parts_to_finish: List[MultipartPart] = []
        self._files_to_close_on_error: List[_TemporaryFileWrapper] = []

    def on_part_begin(self) -> None:
        self._current_part = MultipartPart()

    def on_part_data(self, data: bytes, start: int, end: int) -> None:
        message_bytes = data[start:end]
        if self.upload_progress is not None:
            self.upload_progress.append(
                self.upload_id,  # type: ignore
                self._current_part.file.filename,  # type: ignore
                message_bytes,
            )
        if self._current_part.file is None:
            self._current_part.data += message_bytes
        else:
            self._file_parts_to_write.append((self._current_part, message_bytes))

    def on_part_end(self) -> None:
        if self._current_part.file is None:
            self.items.append(
                (
                    self._current_part.field_name,
                    _user_safe_decode(self._current_part.data, self._charset),
                )
            )
        else:
            self._file_parts_to_finish.append(self._current_part)
            # The file can be added to the items right now even though it's not
            # finished yet, because it will be finished in the `parse()` method, before
            # self.items is used in the return value.
            self.items.append((self._current_part.field_name, self._current_part.file))

    def on_header_field(self, data: bytes, start: int, end: int) -> None:
        self._current_partial_header_name += data[start:end]

    def on_header_value(self, data: bytes, start: int, end: int) -> None:
        self._current_partial_header_value += data[start:end]

    def on_header_end(self) -> None:
        field = self._current_partial_header_name.lower()
        if field == b"content-disposition":
            self._current_part.content_disposition = self._current_partial_header_value
        self._current_part.item_headers.append(
            (field, self._current_partial_header_value)
        )
        self._current_partial_header_name = b""
        self._current_partial_header_value = b""

    def on_headers_finished(self) -> None:
        disposition, options = parse_options_header(
            self._current_part.content_disposition
        )
        try:
            self._current_part.field_name = _user_safe_decode(
                options[b"name"], self._charset
            )
        except KeyError as e:
            raise MultiPartException(
                'The Content-Disposition header field "name" must be ' "provided."
            ) from e
        if b"filename" in options:
            self._current_files += 1
            if self._current_files > self.max_files:
                raise MultiPartException(
                    f"Too many files. Maximum number of files is {self.max_files}."
                )
            filename = _user_safe_decode(options[b"filename"], self._charset)
            tempfile = NamedTemporaryFile(delete=False)
            self._files_to_close_on_error.append(tempfile)
            self._current_part.file = GradioUploadFile(
                file=tempfile,  # type: ignore[arg-type]
                size=0,
                filename=filename,
                headers=Headers(raw=self._current_part.item_headers),
            )
        else:
            self._current_fields += 1
            if self._current_fields > self.max_fields:
                raise MultiPartException(
                    f"Too many fields. Maximum number of fields is {self.max_fields}."
                )
            self._current_part.file = None

    def on_end(self) -> None:
        pass

    async def parse(self) -> FormData:
        # Parse the Content-Type header to get the multipart boundary.
        _, params = parse_options_header(self.headers["Content-Type"])
        charset = params.get(b"charset", "utf-8")
        if isinstance(charset, bytes):
            charset = charset.decode("latin-1")
        self._charset = charset
        try:
            boundary = params[b"boundary"]
        except KeyError as e:
            raise MultiPartException("Missing boundary in multipart.") from e

        # Callbacks dictionary.
        callbacks = {
            "on_part_begin": self.on_part_begin,
            "on_part_data": self.on_part_data,
            "on_part_end": self.on_part_end,
            "on_header_field": self.on_header_field,
            "on_header_value": self.on_header_value,
            "on_header_end": self.on_header_end,
            "on_headers_finished": self.on_headers_finished,
            "on_end": self.on_end,
        }

        # Create the parser.
        parser = multipart.MultipartParser(boundary, callbacks)
        try:
            # Feed the parser with data from the request.
            async for chunk in self.stream:
                parser.write(chunk)
                # Write file data, it needs to use await with the UploadFile methods
                # that call the corresponding file methods *in a threadpool*,
                # otherwise, if they were called directly in the callback methods above
                # (regular, non-async functions), that would block the event loop in
                # the main thread.
                for part, data in self._file_parts_to_write:
                    assert part.file  # for type checkers
                    await part.file.write(data)
                    part.file.sha.update(data)  # type: ignore
                for part in self._file_parts_to_finish:
                    assert part.file  # for type checkers
                    await part.file.seek(0)
                self._file_parts_to_write.clear()
                self._file_parts_to_finish.clear()
        except MultiPartException as exc:
            # Close all the files if there was an error.
            for file in self._files_to_close_on_error:
                file.close()
            raise exc

        parser.finalize()
        if self.upload_progress is not None:
            self.upload_progress.set_done(self.upload_id)  # type: ignore
        return FormData(self.items)


def move_uploaded_files_to_cache(files: list[str], destinations: list[str]) -> None:
    for file, dest in zip(files, destinations):
        shutil.move(file, dest)


def update_root_in_config(config: dict, root: str) -> dict:
    """
    Updates the root "key" in the config dictionary to the new root url. If the
    root url has changed, all of the urls in the config that correspond to component
    file urls are updated to use the new root url.
    """
    previous_root = config.get("root")
    if previous_root is None or previous_root != root:
        config["root"] = root
        config = processing_utils.add_root_url(config, root, previous_root)
    return config


def compare_passwords_securely(input_password: str, correct_password: str) -> bool:
    return hmac.compare_digest(input_password.encode(), correct_password.encode())