1 files changed, 81 insertions, 0 deletions
diff --git a/ext/flash/sendfile.rs b/ext/flash/sendfile.rs
new file mode 100644
index 000000000..4efa7bc35
--- /dev/null
+++ b/ext/flash/sendfile.rs
@@ -0,0 +1,81 @@
+// Forked from https://github.com/Thomasdezeeuw/sendfile/blob/024f82cd4dede9048392a5bd6d8afcd4d5aa83d5/src/lib.rs
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use std::future::Future;
+use std::io;
+use std::os::unix::io::RawFd;
+use std::pin::Pin;
+use std::task::{self, Poll};
+
+pub struct SendFile {
+  pub io: (RawFd, RawFd),
+  pub written: usize,
+}
+
+impl SendFile {
+  #[inline]
+  pub fn try_send(&mut self) -> Result<usize, std::io::Error> {
+    #[cfg(target_os = "linux")]
+    {
+      // This is the maximum the Linux kernel will write in a single call.
+      let count = 0x7ffff000;
+      let mut offset = self.written as libc::off_t;
+
+      // SAFETY: call to libc::sendfile()
+      let res =
+        unsafe { libc::sendfile(self.io.1, self.io.0, &mut offset, count) };
+      if res == -1 {
+        Err(io::Error::last_os_error())
+      } else {
+        self.written = offset as usize;
+        Ok(res as usize)
+      }
+    }
+    #[cfg(target_os = "macos")]
+    {
+      // Send all bytes.
+      let mut length = 0;
+      // On macOS `length` is value-result parameter. It determines the number
+      // of bytes to write and returns the number of bytes written also in
+      // case of `EAGAIN` errors.
+      // SAFETY: call to libc::sendfile()
+      let res = unsafe {
+        libc::sendfile(
+          self.io.0,
+          self.io.1,
+          self.written as libc::off_t,
+          &mut length,
+          std::ptr::null_mut(),
+          0,
+        )
+      };
+      self.written += length as usize;
+      if res == -1 {
+        Err(io::Error::last_os_error())
+      } else {
+        Ok(length as usize)
+      }
+    }
+  }
+}
+
+impl Future for SendFile {
+  type Output = Result<(), std::io::Error>;
+
+  fn poll(
+    mut self: Pin<&mut Self>,
+    _: &mut task::Context<'_>,
+  ) -> Poll<Self::Output> {
+    loop {
+      match self.try_send() {
+        Ok(0) => break Poll::Ready(Ok(())),
+        Ok(_) => continue,
+        Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
+          break Poll::Pending
+        }
+        Err(ref err) if err.kind() == io::ErrorKind::Interrupted => continue, // Try again.
+        Err(err) => break Poll::Ready(Err(err)),
+      }
+    }
+  }
+}