wehub-resource-sync
107 lines
3.5 KiB
Swift
107 lines
3.5 KiB
Swift
//===----------------------------------------------------------------------===//
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// Copyright © 2026 Apple Inc. and the Containerization project authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//===----------------------------------------------------------------------===//
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#if os(Linux)
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import Foundation
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import LCShim
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extension OSFile {
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struct SpliceFile: Sendable {
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fileprivate var file: OSFile
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fileprivate var offset: Int
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fileprivate let pipe = Pipe()
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var fileDescriptor: Int32 {
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file.fileDescriptor
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}
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var reader: Int32 {
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pipe.fileHandleForReading.fileDescriptor
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}
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var writer: Int32 {
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pipe.fileHandleForWriting.fileDescriptor
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}
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init(fd: Int32) {
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self.file = OSFile(fd: fd)
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self.offset = 0
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}
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init(handle: FileHandle) {
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self.file = OSFile(handle: handle)
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self.offset = 0
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}
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init(from: OSFile, withOffset: Int = 0) {
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self.file = from
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self.offset = withOffset
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}
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func close() throws {
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try self.file.close()
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}
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}
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static func splice(from: inout SpliceFile, to: inout SpliceFile, count: Int = 1 << 16) throws -> (read: Int, wrote: Int, action: IOAction) {
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let fromOffset = from.offset
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let toOffset = to.offset
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while true {
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while (from.offset - to.offset) < count {
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let toRead = count - (from.offset - to.offset)
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let bytesRead = LCShim.splice(from.fileDescriptor, nil, to.writer, nil, toRead, UInt32(bitPattern: LCShim.SPLICE_F_MOVE | LCShim.SPLICE_F_NONBLOCK))
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if bytesRead == -1 {
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if errno != EAGAIN && errno != EIO {
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throw POSIXError(.init(rawValue: errno)!)
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}
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break
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}
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if bytesRead == 0 {
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return (0, 0, .eof)
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}
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from.offset += bytesRead
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if bytesRead < toRead {
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break
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}
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}
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if from.offset == to.offset {
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return (from.offset - fromOffset, to.offset - toOffset, .success)
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}
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while to.offset < from.offset {
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let toWrite = from.offset - to.offset
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let bytesWrote = LCShim.splice(to.reader, nil, to.fileDescriptor, nil, toWrite, UInt32(bitPattern: LCShim.SPLICE_F_MOVE | LCShim.SPLICE_F_NONBLOCK))
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if bytesWrote == -1 {
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if errno != EAGAIN && errno != EIO {
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throw POSIXError(.init(rawValue: errno)!)
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}
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break
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}
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to.offset += bytesWrote
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if bytesWrote == 0 {
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return (from.offset - fromOffset, to.offset - toOffset, .brokenPipe)
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}
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if bytesWrote < toWrite {
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break
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}
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}
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}
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}
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}
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#endif
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