From 8f10f1569b58d6f7b5a128c5d19efc0704fe7fa6 Mon Sep 17 00:00:00 2001 From: Eric Eastwood Date: Sun, 23 May 2021 23:15:38 -0500 Subject: [PATCH] Add parse_strings_from_args to get prev_events array Split out from https://github.com/matrix-org/synapse/pull/9247 Strings: - `parse_string` - `parse_string_from_args` - `parse_strings_from_args` For comparison with ints: - `parse_integer` - `parse_integer_from_args` Previous discussions: - https://github.com/matrix-org/synapse/pull/9247#discussion_r573195687 - https://github.com/matrix-org/synapse/pull/9247#discussion_r574214156 - https://github.com/matrix-org/synapse/pull/9247#discussion_r573264791 Signed-off-by: Eric Eastwood --- changelog.d/10048.misc | 1 + synapse/http/servlet.py | 162 +++++++++++++++++++++++++++++++--------- 2 files changed, 126 insertions(+), 37 deletions(-) create mode 100644 changelog.d/10048.misc diff --git a/changelog.d/10048.misc b/changelog.d/10048.misc new file mode 100644 index 000000000000..a901f8431e9e --- /dev/null +++ b/changelog.d/10048.misc @@ -0,0 +1 @@ +Add `parse_strings_from_args` for parsing an array from query parameters. diff --git a/synapse/http/servlet.py b/synapse/http/servlet.py index 31897546a967..17242d6909f8 100644 --- a/synapse/http/servlet.py +++ b/synapse/http/servlet.py @@ -15,6 +15,7 @@ """ This module contains base REST classes for constructing REST servlets. """ import logging +from typing import Iterable, List, Optional, Union from synapse.api.errors import Codes, SynapseError from synapse.util import json_decoder @@ -107,12 +108,11 @@ def parse_boolean_from_args(args, name, default=None, required=False): def parse_string( request, - name, - default=None, - required=False, - allowed_values=None, - param_type="string", - encoding="ascii", + name: Union[bytes, str], + default: Optional[str] = None, + required: bool = False, + allowed_values: Optional[Iterable[str]] = None, + encoding: Optional[str] = "ascii", ): """ Parse a string parameter from the request query string. @@ -131,7 +131,6 @@ def parse_string( string, or None if any value is allowed, defaults to None. Must be the same type as name, if given. encoding (str|None): The encoding to decode the string content with. - Returns: bytes/unicode|None: A string value or the default. Unicode if encoding was given, bytes otherwise. @@ -142,45 +141,81 @@ def parse_string( is not one of those allowed values. """ return parse_string_from_args( - request.args, name, default, required, allowed_values, param_type, encoding + request.args, name, default, required, allowed_values, encoding ) -def parse_string_from_args( - args, - name, - default=None, - required=False, - allowed_values=None, - param_type="string", - encoding="ascii", -): +def _parse_string_value( + value: Union[str, bytes], + allowed_values: Optional[Iterable[str]], + name: str, + encoding: Optional[str], +) -> str: + if encoding: + try: + value = value.decode(encoding) + except ValueError: + raise SynapseError(400, "Query parameter %r must be %s" % (name, encoding)) + + if allowed_values is not None and value not in allowed_values: + message = "Query parameter %r must be one of [%s]" % ( + name, + ", ".join(repr(v) for v in allowed_values), + ) + raise SynapseError(400, message) + else: + return value + + +def parse_strings_from_args( + args: List[str], + name: Union[bytes, str], + default: Optional[str] = None, + required: bool = False, + allowed_values: Optional[Iterable[str]] = None, + encoding: Optional[str] = "ascii", +) -> Optional[List[Union[bytes, str]]]: + """ + Parse a string parameter from the request query string list. + + If encoding is not None, the content of the query param will be + decoded to Unicode using the encoding, otherwise it will be encoded + + Args: + args: the twisted HTTP request.args list. + name: the name of the query parameter. + default: value to use if the parameter is absent, + defaults to None. Must be bytes if encoding is None. + required : whether to raise a 400 SynapseError if the + parameter is absent, defaults to False. + allowed_values (list[bytes|unicode]): List of allowed values for the + string, or None if any value is allowed, defaults to None. Must be + the same type as name, if given. + encoding: The encoding to decode the string content with. + + Returns: + A string value or the default. Unicode if encoding + was given, bytes otherwise. + + Raises: + SynapseError if the parameter is absent and required, or if the + parameter is present, must be one of a list of allowed values and + is not one of those allowed values. + """ if not isinstance(name, bytes): name = name.encode("ascii") if name in args: - value = args[name][0] - - if encoding: - try: - value = value.decode(encoding) - except ValueError: - raise SynapseError( - 400, "Query parameter %r must be %s" % (name, encoding) - ) - - if allowed_values is not None and value not in allowed_values: - message = "Query parameter %r must be one of [%s]" % ( - name, - ", ".join(repr(v) for v in allowed_values), - ) - raise SynapseError(400, message) - else: - return value + values = args[name] + + return [ + _parse_string_value(value, allowed_values, name=name, encoding=encoding) + for value in values + ] else: if required: - message = "Missing %s query parameter %r" % (param_type, name) + message = "Missing string query parameter %r" % (name) raise SynapseError(400, message, errcode=Codes.MISSING_PARAM) else: @@ -190,6 +225,59 @@ def parse_string_from_args( return default +def parse_string_from_args( + args: List[str], + name: Union[bytes, str], + default: Optional[str] = None, + required: bool = False, + allowed_values: Optional[Iterable[str]] = None, + encoding: Optional[str] = "ascii", +) -> Optional[Union[bytes, str]]: + """ + Parse the string parameter from the request query string list + and return the first result. + + If encoding is not None, the content of the query param will be + decoded to Unicode using the encoding, otherwise it will be encoded + + Args: + args: the twisted HTTP request.args list. + name: the name of the query parameter. + default: value to use if the parameter is absent, + defaults to None. Must be bytes if encoding is None. + required: whether to raise a 400 SynapseError if the + parameter is absent, defaults to False. + allowed_values: List of allowed values for the + string, or None if any value is allowed, defaults to None. Must be + the same type as name, if given. + encoding: The encoding to decode the string content with. + + Returns: + A string value or the default. Unicode if encoding + was given, bytes otherwise. + + Raises: + SynapseError if the parameter is absent and required, or if the + parameter is present, must be one of a list of allowed values and + is not one of those allowed values. + """ + + strings = parse_strings_from_args( + args, + name, + default=default, + required=required, + allowed_values=allowed_values, + encoding=encoding, + ) + + if isinstance(strings, list): + return strings[0] + + # Return the default + return strings + + def parse_json_value_from_request(request, allow_empty_body=False): """Parse a JSON value from the body of a twisted HTTP request. @@ -215,7 +303,7 @@ def parse_json_value_from_request(request, allow_empty_body=False): try: content = json_decoder.decode(content_bytes.decode("utf-8")) except Exception as e: - logger.warning("Unable to parse JSON: %s", e) + logger.warning("Unable to parse JSON: %s (%s)", e, content_bytes) raise SynapseError(400, "Content not JSON.", errcode=Codes.NOT_JSON) return content