| use std::fmt; |
| |
| /// Alternative implementation of `fmt::Debug` for byte slice. |
| /// |
| /// Standard `Debug` implementation for `[u8]` is comma separated |
| /// list of numbers. Since large amount of byte strings are in fact |
| /// ASCII strings or contain a lot of ASCII strings (e. g. HTTP), |
| /// it is convenient to print strings as ASCII when possible. |
| /// |
| /// This struct wraps `&[u8]` just to override `fmt::Debug`. |
| /// |
| /// `BsDebug` is not a part of public API of bytes crate. |
| pub struct BsDebug<'a>(pub &'a [u8]); |
| |
| impl<'a> fmt::Debug for BsDebug<'a> { |
| fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> { |
| try!(write!(fmt, "b\"")); |
| for &c in self.0 { |
| // https://doc.rust-lang.org/reference.html#byte-escapes |
| if c == b'\n' { |
| try!(write!(fmt, "\\n")); |
| } else if c == b'\r' { |
| try!(write!(fmt, "\\r")); |
| } else if c == b'\t' { |
| try!(write!(fmt, "\\t")); |
| } else if c == b'\\' || c == b'"' { |
| try!(write!(fmt, "\\{}", c as char)); |
| } else if c == b'\0' { |
| try!(write!(fmt, "\\0")); |
| // ASCII printable |
| } else if c >= 0x20 && c < 0x7f { |
| try!(write!(fmt, "{}", c as char)); |
| } else { |
| try!(write!(fmt, "\\x{:02x}", c)); |
| } |
| } |
| try!(write!(fmt, "\"")); |
| Ok(()) |
| } |
| } |