hex view

src/ext.rs

@@ -7,6 +7,9 @@ use std::{
     ops::{
 	Range,
     },
+    marker::{
+	PhantomData,
+    },
 };
 use tokio::{
     io::AsyncRead,
@@ -131,12 +134,105 @@ const ASCII_MAP: [char; 256] = [
     '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.',
 ];
 
-pub struct HexStringIter<'a, I>(&'a I, bool);
-pub struct HexView<'a, I>(&'a I);
+const fn create_hex_map() -> [(u8, u8); 256]
+{
+    let mut out = [(0, 0); 256];
+    const HEX: &[u8; 16] = b"0123456789abcdef";
+    let mut i = 0usize;
+    while i <= 255
+    {
+	out[i] = (
+	    HEX[i >> 4],
+	    HEX[i & 0xf]
+	);
+	i+=1;
+    }
+    out
+}
+const HEX_MAP: [(u8, u8); 256] = create_hex_map();
+
+pub struct HexStringView<'a, I:?Sized>(&'a I, bool);
+pub struct HexStringIter<'a, I:?Sized>(std::slice::Iter<'a, u8>, (u8, u8), PhantomData<&'a I>);
+
+pub struct HexView<'a, I:?Sized>(&'a I);
+
+pub struct AsciiView<'a, I:?Sized>(&'a I);
+pub struct AsciiIter<'a, I:?Sized>(&'a [u8], PhantomData<&'a I>);
 
 const SPLIT_EVERY: usize = 16;
 
-impl<'a, I: AsRef<[u8]>> fmt::Display for HexView<'a, I>
+impl<'a, I: ?Sized+AsRef<[u8]>> Iterator for AsciiIter<'a, I>
+{
+    type Item = char;
+    fn next(&mut self) -> Option<Self::Item>
+    {
+	match match self.0 {
+	    [] => None,
+	    [chr, ..] => Some(ASCII_MAP[*chr as usize]),
+	} {
+	    x @ Some(_) => {
+		self.0 = &self.0[1..];
+		x
+	    },
+	    _ => None,
+	}   
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+	(self.0.len(), Some(self.0.len()))
+    }
+}
+impl<'a, I: ?Sized+AsRef<[u8]>> ExactSizeIterator for AsciiIter<'a, I>{}
+impl<'a, I: ?Sized+AsRef<[u8]>> std::iter::FusedIterator for AsciiIter<'a, I>{}
+
+impl<'a, I: ?Sized+AsRef<[u8]>> Iterator for HexStringIter<'a, I>
+{
+    type Item = char;
+    fn next(&mut self) -> Option<Self::Item>
+    {
+	match self.1 {
+	    ref mut buf @ (0, 0) => {
+		// both are taken
+		if let Some(&byte) = self.0.next() {
+		    *buf = HEX_MAP[byte as usize];
+		} else {
+		    return None;
+		}
+		(Some(buf.0 as char),buf.0 = 0).0
+	    },
+	    (0, ref mut second) => {
+		// first is taken
+		(Some(*second as char),*second = 0).0
+	    },
+	    #[cold] (ref mut first, _) => {
+		// neither are taken, usually shouldn't happen
+		(Some(*first as char),*first = 0).0
+	    },
+	}
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+	let sz = self.0.size_hint();
+	(sz.0 * 2, sz.1.map(|x| x*2))
+    }
+}
+impl<'a, I: ?Sized+AsRef<[u8]>> ExactSizeIterator for HexStringIter<'a, I>{}
+impl<'a, I: ?Sized+AsRef<[u8]>> std::iter::FusedIterator for HexStringIter<'a, I>{}
+
+impl<'a, I: AsRef<[u8]>+?Sized> fmt::Display for AsciiView<'a, I>
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
+    {
+	for byte in self.0.as_ref().iter().map(|&byte| ASCII_MAP[byte as usize])
+	{
+	    use std::fmt::Write;
+	    f.write_char(byte)?;
+	}
+	Ok(())
+    }
+}
+
+impl<'a, I: AsRef<[u8]>+?Sized> fmt::Display for HexView<'a, I>
 {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
     {
@@ -178,7 +274,7 @@ impl<'a, I: AsRef<[u8]>> fmt::Display for HexView<'a, I>
     }
 }
 
-impl<'a, I: AsRef<[u8]>> fmt::Display for HexStringIter<'a, I>
+impl<'a, I: AsRef<[u8]>+?Sized> fmt::Display for HexStringView<'a, I>
 {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
     {
@@ -202,10 +298,26 @@ impl<'a, I: AsRef<[u8]>> fmt::Display for HexStringIter<'a, I>
     }
 }
 
-pub trait HexStringExt: Sized + AsRef<[u8]>
+/// Extensions on byte slices to print them nicely
+pub trait HexStringExt: AsRef<[u8]>
 {
+    /// An iterator that prints readable ascii of each byte
+    fn iter_ascii(&self) -> AsciiIter<'_, Self>;
+    /// A `Display` implementor that prints ascii of each byte
+    fn fmt_ascii(&self) -> AsciiView<'_, Self>;
+    
+    /// A pretty hex view `Display` implementor of the bytes
     fn fmt_view(&self) -> HexView<'_, Self>;
-    fn fmt_hex(&self) -> HexStringIter<'_, Self>;
+
+    /// A `Display` implementor that prints the hex of each byte in lowercase
+    fn fmt_hex(&self) -> HexStringView<'_, Self>;
+    /// An iterator over `char`s that yields the hex of each byte
+    ///
+    /// # Notes
+    /// This yields each character one at a time, to get the hex of each byte, chunk it with a window of 2.
+    fn iter_hex(&self) -> HexStringIter<'_, Self>;
+
+    /// Convenience method for creating a hex string.
     fn to_hex_string(&self) -> String
     {
 	let mut string = String::with_capacity(self.as_ref().len()*2);
@@ -213,9 +325,11 @@ pub trait HexStringExt: Sized + AsRef<[u8]>
 	write!(&mut string, "{}", self.fmt_hex()).unwrap();
 	string
     }
+
+    /// Convenience method for creating a hex string with each byte broken by a hyphen.
     fn to_broken_hex_string(&self) -> String
     {
-	let fmt = HexStringIter(
+	let fmt = HexStringView(
 	    self.fmt_hex().0,
 	    true
 	);
@@ -224,13 +338,37 @@ pub trait HexStringExt: Sized + AsRef<[u8]>
 	write!(&mut string, "{}", fmt).unwrap();
 	string
     }
+    /// Convenience method for creating a string from `fmt_view()`
+    #[inline] fn to_view_string(&self) -> String
+    {
+	format!("{}", self.fmt_view())
+    }
+
+    /// Convenience method for creating a string from `fmt_ascii()`
+    
+    #[inline] fn to_ascii_string(&self) -> String
+    {
+	self.iter_ascii().collect()
+    }
 }
 
-impl<T: AsRef<[u8]>> HexStringExt for T
+impl<T: AsRef<[u8]>+?Sized> HexStringExt for T
+{
+    fn iter_hex(&self) -> HexStringIter<'_, Self>
+    {
+	HexStringIter(self.as_ref().iter(), (0,0), PhantomData)
+    }
+    fn iter_ascii(&self) -> AsciiIter<'_, Self>
     {
-    fn fmt_hex(&self) -> HexStringIter<'_, Self>
+	AsciiIter(self.as_ref(), PhantomData)
+    }
+    fn fmt_ascii(&self) -> AsciiView<'_, Self>
+    {
+	AsciiView(&self)
+    }
+    fn fmt_hex(&self) -> HexStringView<'_, Self>
     {
-	HexStringIter(&self, false)
+	HexStringView(&self, false)
     }
     
     fn fmt_view(&self) -> HexView<'_, Self>