ladybird/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP.cpp

78 lines
2.5 KiB
C++

/*
* Copyright (c) 2022, Luke Wilde <lukew@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/GenericLexer.h>
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <LibWeb/Fetch/Infrastructure/HTTP.h>
namespace Web::Fetch::Infrastructure {
// https://fetch.spec.whatwg.org/#collect-an-http-quoted-string
String collect_an_http_quoted_string(GenericLexer& lexer, HttpQuotedStringExtractValue extract_value)
{
// To collect an HTTP quoted string from a string input, given a position variable position and optionally an extract-value flag, run these steps:
// 1. Let positionStart be position.
auto position_start = lexer.tell();
// 2. Let value be the empty string.
StringBuilder value;
// 3. Assert: the code point at position within input is U+0022 (").
VERIFY(lexer.peek() == '"');
// 4. Advance position by 1.
lexer.ignore(1);
// 5. While true:
while (true) {
// 1. Append the result of collecting a sequence of code points that are not U+0022 (") or U+005C (\) from input, given position, to value.
auto value_part = lexer.consume_until([](char ch) {
return ch == '"' || ch == '\\';
});
value.append(value_part);
// 2. If position is past the end of input, then break.
if (lexer.is_eof())
break;
// 3. Let quoteOrBackslash be the code point at position within input.
// 4. Advance position by 1.
char quote_or_backslash = lexer.consume();
// 5. If quoteOrBackslash is U+005C (\), then:
if (quote_or_backslash == '\\') {
// 1. If position is past the end of input, then append U+005C (\) to value and break.
if (lexer.is_eof()) {
value.append('\\');
break;
}
// 2. Append the code point at position within input to value.
// 3. Advance position by 1.
value.append(lexer.consume());
}
// 6. Otherwise:
else {
// 1. Assert: quoteOrBackslash is U+0022 (").
VERIFY(quote_or_backslash == '"');
// 2. Break.
break;
}
}
// 6. If the extract-value flag is set, then return value.
if (extract_value == HttpQuotedStringExtractValue::Yes)
return MUST(value.to_string());
// 7. Return the code points from positionStart to position, inclusive, within input.
return MUST(String::from_utf8(lexer.input().substring_view(position_start, lexer.tell() - position_start)));
}
}