Merge pull request #706 from erickt/master

Switch rand_os to use fuchsia-cprng crate in rand-0.6

rand_os/Cargo.toml

@@ -28,7 +28,7 @@ winapi = { version = "0.3", features = ["minwindef", "ntsecapi", "winnt"] }
 cloudabi = "0.0.3"
 
 [target.'cfg(target_os = "fuchsia")'.dependencies]
-fuchsia-zircon = "0.3.2"
+fuchsia-cprng = "0.1.0"
 
 [target.wasm32-unknown-unknown.dependencies]
 wasm-bindgen = { version = "0.2.12", optional = true }

rand_os/src/fuchsia.rs

@@ -8,9 +8,9 @@
 
 //! Implementation for Fuchsia Zircon
 
-extern crate fuchsia_zircon;
+extern crate fuchsia_cprng;
 
-use rand_core::{Error, ErrorKind};
+use rand_core::Error;
 use super::OsRngImpl;
 
 #[derive(Clone, Debug)]
@@ -20,24 +20,9 @@ impl OsRngImpl for OsRng {
     fn new() -> Result<OsRng, Error> { Ok(OsRng) }
 
     fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        let mut read = 0;
-        while read < dest.len() {
-            match fuchsia_zircon::cprng_draw(&mut dest[read..]) {
-                Ok(actual) => read += actual,
-                Err(e) => {
-                    return Err(Error::with_cause(
-                        ErrorKind::Unavailable,
-                        "cprng_draw failed",
-                        e.into_io_error()));
-                }
-            };
-        }
+        fuchsia_cprng::cprng_draw(dest);
         Ok(())
     }
 
-    fn max_chunk_size(&self) -> usize {
-        fuchsia_zircon::sys::ZX_CPRNG_DRAW_MAX_LEN
-    }
-
     fn method_str(&self) -> &'static str { "cprng_draw" }
 }