sys::sendfile adding solaris' sendfilev wrapper proposal.

src/sys/sendfile.rs

@@ -120,6 +120,49 @@ cfg_if! {
                 )
             }
         }
+    } else if #[cfg(any(target_os = "solaris", target_os = "illumos"))] {
+        #[derive(Clone, Debug, Copy)]
+        /// Mapping of the raw C sendfilevec_t struct
+        /// no need to bother with `sfv_flag` since it needs to be always 0.
+        pub struct SendfileVec {
+            /// input file descriptor
+            pub fd: i32,
+            /// offset to read from
+            pub off: isize,
+            /// size of the data to read
+            pub len: usize,
+        }
+
+        const SFV_FD_SELF: i32 = -2;
+
+        impl SendfileVec {
+            /// initialises SendfileVec to send data directly from the process's address space
+            /// same in C with sfv_fd set to SFV_FD_SELF.
+            pub fn newself(
+                off: isize,
+                len: usize
+            ) -> SendfileVec {
+                SendfileVec{fd: SFV_FD_SELF, off, len}
+            }
+
+            /// initialises SendfileVec to send data from `fd`.
+            pub fn new(
+                fd: i32,
+                off: isize,
+                len: usize
+            ) -> SendfileVec {
+                SendfileVec{fd, off, len}
+            }
+
+            fn tosendfilevec(&self) -> libc::sendfilevec_t {
+                libc::sendfilevec_t{
+                    sfv_fd: self.fd,
+                    sfv_flag: 0,
+                    sfv_off: self.off as off_t,
+                    sfv_len: self.len
+                }
+            }
+        }
     }
 }
 
@@ -287,5 +330,30 @@ cfg_if! {
             };
             (Errno::result(return_code).and(Ok(())), len)
         }
+    } else if #[cfg(any(target_os = "solaris", target_os = "illumos"))] {
+        /// Write data from the vec arrays to `out_sock` and returns a `Result` and a
+        /// count of bytes written.
+        ///
+        /// Each `SendfileVec` set needs to be instantiated either with `SendfileVec::new` or
+        /// `SendfileVec::newself`.
+        ///
+        /// The former allows to send data from a file descriptor through `fd`,
+        ///  from an offset `off` and for a given amount of data `len`.
+        ///
+        /// The latter allows to send data from the process' address space, from an offset `off`
+        /// and for a given amount of data `len`.
+        ///
+        /// For more information, see
+        /// [the sendfilev{3) man page.](https://docs.oracle.com/cd/E86824_01/html/E54768/sendfilev-3ext.html)
+        pub fn sendfilev<F1: AsFd, F2: AsFd>(
+            out_sock: F2,
+            vec: Vec<SendfileVec>
+        ) -> Result<usize> {
+            let rawvec: Vec<libc::sendfilevec_t> = vec.iter().map(|&v| v.tosendfilevec()).collect();
+            let ret = unsafe {
+                libc::sendfilev(out_sock.as_fd().as_raw_fd(), rawvec.as_ptr(), rawvec.len() as i32, ptr::null_mut())
+            };
+            Errno::result(ret).map(|r| r as usize)
+        }
     }
 }