Add silly hex encoder

Cargo.lock

@@ -1,5 +1,14 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "aho-corasick"
+version = "0.7.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8716408b8bc624ed7f65d223ddb9ac2d044c0547b6fa4b0d554f3a9540496ada"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.0.0"
@@ -63,6 +72,8 @@ version = "0.1.0"
 dependencies = [
  "byteorder",
  "chrono",
+ "lazy_static",
+ "regex",
  "thiserror",
  "tokio",
 ]
@@ -222,6 +233,24 @@ version = "0.1.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
 
+[[package]]
+name = "regex"
+version = "1.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8900ebc1363efa7ea1c399ccc32daed870b4002651e0bed86e72d501ebbe0048"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+ "thread_local",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fe5bd57d1d7414c6b5ed48563a2c855d995ff777729dcd91c369ec7fea395ae"
+
 [[package]]
 name = "slab"
 version = "0.4.2"
@@ -259,6 +288,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "thread_local"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d40c6d1b69745a6ec6fb1ca717914848da4b44ae29d9b3080cbee91d72a69b14"
+dependencies = [
+ "lazy_static",
+]
+
 [[package]]
 name = "time"
 version = "0.1.42"

hptp/Cargo.toml

@@ -11,4 +11,6 @@ edition = "2018"
 tokio = {version = "0.2.*", features = ["io-std", "io-util", "udp"]}
 thiserror = "*"
 chrono = "0.4.*"
-byteorder = "1.3.*"
+byteorder = "1.3.*"
+regex = "1.3.*"
+lazy_static = "1.4.*"

hptp/src/encoding.rs

@@ -0,0 +1,112 @@
+use lazy_static::lazy_static;
+use regex::bytes::Regex;
+
+lazy_static! {
+    static ref ENCODING_DETECTOR: Regex = Regex::new(r"^([0-9a-fA-F]{60}\n)*[0-9a-fA-F]{0,60}$").unwrap();
+}
+
+static WRAP_SIZE: usize = 60;
+
+pub fn can_be_encoded(data: &[u8]) -> bool {
+    ENCODING_DETECTOR.is_match(data)
+}
+
+#[derive(Clone)]
+pub struct MeowCoder {
+    line_index: usize,
+}
+
+impl MeowCoder {
+    pub fn new() -> MeowCoder {
+        MeowCoder{line_index: 0}
+    }
+
+    fn hex_to_nibble(chr: u8) -> u8 {
+        const _AL: u8 = 'a' as u8;
+        const _FL: u8 = 'f' as u8;
+        const _A: u8 = 'A' as u8;
+        const _F: u8 = 'F' as u8;
+        const _0: u8 = '0' as u8;
+        const _9: u8 = '9' as u8;
+        match chr {
+            _AL..=_FL => chr - _AL + 10,
+            _A..=_F => chr - _A + 10,
+            _0..=_9 => chr - _0,
+            _ => panic!("bad hex"),
+        }
+    }
+
+    fn u8_to_hex(val: u8) -> (u8, u8) {
+        let first = val >> 4;
+        let second = val & 0xF;
+        const LOOKUP: &'static [u8; 16] = b"0123456789abcdef";
+        (LOOKUP[first as usize], LOOKUP[second as usize])
+    }
+
+    pub fn encode(input: &Vec<u8>) -> Vec<u8> {
+        let mut out: Vec<u8> = Vec::new();
+        let mut prev_char: u8 = 0;
+        let mut pair_first = false;
+        for chr in input {
+            if *chr == '\n' as u8 {
+                continue
+            }
+            if !pair_first {
+                prev_char = *chr;
+                pair_first = true;
+            } else {
+                let byte_value: u8 = MeowCoder::hex_to_nibble(prev_char) * 16
+                    + MeowCoder::hex_to_nibble(*chr);
+                out.push(byte_value);
+                pair_first = false;
+            }
+        }
+        out
+    }
+
+    pub fn decode(&mut self, input: &Vec<u8>) -> Vec<u8> {
+        let mut out: Vec<u8> = Vec::new();
+        for byte in input {
+            let (first, second) = MeowCoder::u8_to_hex(*byte);
+            out.push(first);
+            out.push(second);
+            self.line_index += 2;
+            if self.line_index == WRAP_SIZE {
+                self.line_index = 0;
+                out.push('\n' as u8);
+            }
+        }
+        out
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_match() {
+        assert_eq!(can_be_encoded(b"abcd1234"), true);
+        assert_eq!(can_be_encoded(b"abcXd1234"), false);
+        assert_eq!(can_be_encoded(b"012345678901234567890123456789012345678901234567890123456789\nabcdef"), true);
+        assert_eq!(can_be_encoded(b"01234567890123456789012345678901234567890123456789012345678\nabcdef"), false);
+        assert_eq!(can_be_encoded(b"\x12\xab\x45\n"), false);
+    }
+
+    #[test]
+    fn test_encode() {
+        let vec = vec!['a' as u8, 'b' as u8, 'c' as u8, 'd' as u8,
+            '\n' as u8, 'e' as u8, 'f' as u8];
+        assert_eq!(MeowCoder::encode(&vec), vec![0xab, 0xcd, 0xef]);
+    }
+
+    #[test]
+    fn test_encode_decode() {
+        let hex_str: &[u8] = b"012345678901234567890123456789012345678901234567890123456789\nabcdef";
+        let vec: Vec<u8> = Vec::from(hex_str);
+        let vec2 = MeowCoder::encode(&vec);
+        let mut coder = MeowCoder::new();
+        let out = coder.decode(&vec2);
+        assert_eq!(out, vec);
+    }
+}

hptp/src/lib.rs

@@ -7,3 +7,4 @@ pub mod logger;
 pub mod msg;
 pub mod peer;
 pub mod seg;
+pub mod encoding;

hptp/src/msg.rs

@@ -43,6 +43,7 @@ impl SerDes for UpMsg {
                 payload: SegData {
                     bytes: buf[4..].into(),
                     is_last_segment: (hdr & LAST_SEG_MASK) != 0,
+                    is_meow_encoded: false,
                 },
             })
         }
@@ -55,6 +56,7 @@ impl SerDes for UpMsg {
                     SegData {
                         bytes,
                         is_last_segment,
+                        is_meow_encoded,
                     },
                 seg_idx,
             } => {

hptp/src/seg.rs

@@ -50,9 +50,9 @@ pub struct SegmentSet {
 
 #[derive(Clone)]
 pub struct SegData {
-    // TODO: encoding
     pub(crate) bytes: Vec<u8>,
     pub is_last_segment: bool,
+    pub is_meow_encoded: bool,
 }
 
 impl SegData {
@@ -71,11 +71,13 @@ impl SegData {
             Ok(SegData {
                 bytes: Vec::from(&buf[..len]),
                 is_last_segment: false,
+                is_meow_encoded: false,
             })
         } else {
             Ok(SegData {
                 bytes: vec![],
                 is_last_segment: true,
+                is_meow_encoded: false,
             })
         }
     }