From eef3e9c55685623fe4373600682ffb5e3764c3e6 Mon Sep 17 00:00:00 2001
From: meh <meh@schizofreni.co>
Date: Thu, 7 May 2015 04:32:32 +0200
Subject: [PATCH] util/error: add error handling

---
 src/lib.rs        |  1 +
 src/util/error.rs | 50 +++++++++++++++++++++++++++++++++++++++++++++++
 src/util/mod.rs   |  2 ++
 3 files changed, 53 insertions(+)
 create mode 100644 src/util/error.rs

diff --git a/src/lib.rs b/src/lib.rs
index 5be08db..385faa7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,3 +5,4 @@ extern crate ffmpeg_sys as ffi;
 #[macro_use] extern crate bitflags;
 
 pub mod util;
+pub use util::error::Error;
diff --git a/src/util/error.rs b/src/util/error.rs
new file mode 100644
index 0000000..f60a70e
--- /dev/null
+++ b/src/util/error.rs
@@ -0,0 +1,50 @@
+use ffi::*;
+use std::error;
+use std::fmt;
+use std::cell::RefCell;
+use libc::c_int;
+use std::ffi::CStr;
+use std::str::from_utf8_unchecked;
+
+pub struct Error {
+	code: c_int,
+	desc: RefCell<Option<[i8; AV_ERROR_MAX_STRING_SIZE as usize]>>,
+}
+
+impl Error {
+	pub fn new(code: c_int) -> Self {
+		Error { code: code, desc: RefCell::new(None) }
+	}
+}
+
+impl fmt::Display for Error {
+	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+		f.write_str(error::Error::description(self))
+	}
+}
+
+impl fmt::Debug for Error {
+	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+		try!(f.write_str("ffmpeg::Error("));
+		try!(f.write_str(&format!("{}: ", AVUNERROR(self.code))));
+		try!(fmt::Display::fmt(self, f));
+		f.write_str(")")
+	}
+}
+
+impl error::Error for Error {
+	fn description(&self) -> &str {
+		unsafe {
+			let mut desc = self.desc.borrow_mut();
+
+			if let None = *desc {
+				let mut buf = [0i8; AV_ERROR_MAX_STRING_SIZE as usize];
+				av_strerror(self.code, buf.as_mut_ptr(), AV_ERROR_MAX_STRING_SIZE);
+
+				*desc = Some(buf);
+			}
+
+			from_utf8_unchecked(CStr::from_ptr(desc.unwrap().as_ptr()).to_bytes())
+		}
+	}
+}
diff --git a/src/util/mod.rs b/src/util/mod.rs
index 1a907d8..4b7ef5a 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -1,3 +1,5 @@
+pub mod error;
+
 use std::ffi::CStr;
 use std::str::from_utf8_unchecked;