swift-nio/Sources/NIOHTTP1/ByteCollectionUtils.swift

74 lines
2.9 KiB
Swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the SwiftNIO open source project
//
// Copyright (c) 2017-2021 Apple Inc. and the SwiftNIO project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
import NIOCore
fileprivate let defaultWhitespaces = [" ", "\t"].map({$0.utf8.first!})
extension ByteBufferView {
internal func trim(limitingElements: [UInt8]) -> ByteBufferView {
guard let lastNonWhitespaceIndex = self.lastIndex(where: { !limitingElements.contains($0) }),
let firstNonWhitespaceIndex = self.firstIndex(where: { !limitingElements.contains($0) }) else {
// This buffer is entirely trimmed elements, so trim it to nothing.
return self[self.startIndex..<self.startIndex]
}
return self[firstNonWhitespaceIndex..<index(after: lastNonWhitespaceIndex)]
}
internal func trimSpaces() -> ByteBufferView {
return trim(limitingElements: defaultWhitespaces)
}
}
extension Sequence where Self.Element == UInt8 {
/// Compares the collection of `UInt8`s to a case insensitive collection.
///
/// This collection could be get from applying the `UTF8View`
/// property on the string protocol.
///
/// - Parameter bytes: The string constant in the form of a collection of `UInt8`
/// - Returns: Whether the collection contains **EXACTLY** this array or no, but by ignoring case.
internal func compareCaseInsensitiveASCIIBytes<T: Sequence>(to: T) -> Bool
where T.Element == UInt8 {
// fast path: we can get the underlying bytes of both
let maybeMaybeResult = self.withContiguousStorageIfAvailable { lhsBuffer -> Bool? in
to.withContiguousStorageIfAvailable { rhsBuffer in
if lhsBuffer.count != rhsBuffer.count {
return false
}
for idx in 0 ..< lhsBuffer.count {
// let's hope this gets vectorised ;)
if lhsBuffer[idx] & 0xdf != rhsBuffer[idx] & 0xdf {
return false
}
}
return true
}
}
if let maybeResult = maybeMaybeResult, let result = maybeResult {
return result
} else {
return self.elementsEqual(to, by: {return ($0 & 0xdf) == ($1 & 0xdf)})
}
}
}
extension String {
internal func isEqualCaseInsensitiveASCIIBytes(to: String) -> Bool {
return self.utf8.compareCaseInsensitiveASCIIBytes(to: to.utf8)
}
}