chore: import upstream snapshot with attribution

2026-07-13 12:25:30 +08:00
commit 680845cb1c
445 changed files with 103779 additions and 0 deletions
@@ -0,0 +1,106 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2026 Apple Inc. and the Containerization project authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+#if os(Linux)
+
+import Foundation
+import LCShim
+
+extension OSFile {
+    struct SpliceFile: Sendable {
+        fileprivate var file: OSFile
+        fileprivate var offset: Int
+        fileprivate let pipe = Pipe()
+
+        var fileDescriptor: Int32 {
+            file.fileDescriptor
+        }
+
+        var reader: Int32 {
+            pipe.fileHandleForReading.fileDescriptor
+        }
+
+        var writer: Int32 {
+            pipe.fileHandleForWriting.fileDescriptor
+        }
+
+        init(fd: Int32) {
+            self.file = OSFile(fd: fd)
+            self.offset = 0
+        }
+
+        init(handle: FileHandle) {
+            self.file = OSFile(handle: handle)
+            self.offset = 0
+        }
+
+        init(from: OSFile, withOffset: Int = 0) {
+            self.file = from
+            self.offset = withOffset
+        }
+
+        func close() throws {
+            try self.file.close()
+        }
+    }
+
+    static func splice(from: inout SpliceFile, to: inout SpliceFile, count: Int = 1 << 16) throws -> (read: Int, wrote: Int, action: IOAction) {
+        let fromOffset = from.offset
+        let toOffset = to.offset
+
+        while true {
+            while (from.offset - to.offset) < count {
+                let toRead = count - (from.offset - to.offset)
+                let bytesRead = LCShim.splice(from.fileDescriptor, nil, to.writer, nil, toRead, UInt32(bitPattern: LCShim.SPLICE_F_MOVE | LCShim.SPLICE_F_NONBLOCK))
+                if bytesRead == -1 {
+                    if errno != EAGAIN && errno != EIO {
+                        throw POSIXError(.init(rawValue: errno)!)
+                    }
+                    break
+                }
+                if bytesRead == 0 {
+                    return (0, 0, .eof)
+                }
+                from.offset += bytesRead
+                if bytesRead < toRead {
+                    break
+                }
+            }
+            if from.offset == to.offset {
+                return (from.offset - fromOffset, to.offset - toOffset, .success)
+            }
+            while to.offset < from.offset {
+                let toWrite = from.offset - to.offset
+                let bytesWrote = LCShim.splice(to.reader, nil, to.fileDescriptor, nil, toWrite, UInt32(bitPattern: LCShim.SPLICE_F_MOVE | LCShim.SPLICE_F_NONBLOCK))
+                if bytesWrote == -1 {
+                    if errno != EAGAIN && errno != EIO {
+                        throw POSIXError(.init(rawValue: errno)!)
+                    }
+                    break
+                }
+                to.offset += bytesWrote
+                if bytesWrote == 0 {
+                    return (from.offset - fromOffset, to.offset - toOffset, .brokenPipe)
+                }
+                if bytesWrote < toWrite {
+                    break
+                }
+            }
+        }
+    }
+}
+
+#endif