1 files changed, 283 insertions, 4 deletions

diff --git a/rust/src/lib.rs b/rust/src/lib.rs
index 88b999d..300fa99 100644
--- a/rust/src/lib.rs
+++ b/rust/src/lib.rs
@@ -3,7 +3,9 @@ use std::vec::Vec;
 use std::io::{Write,Read};
 use std::num::FpCategory;
 use std::sync::LazyLock;
+use std::io::Cursor;
 
+#[derive(PartialEq)]
 pub enum Value {
     Integer(i64),
     ByteString(Vec<u8>),
@@ -14,6 +16,44 @@ pub enum Value {
     Nothing,
 }
 
+pub enum ValueParse {
+    Value(Value),
+    EndMarker,
+}
+
+impl PartialEq<i64> for Value {
+    fn eq(&self, other: &i64) -> bool {
+        if let Value::Integer(x) = self {
+            x == other
+        } else {
+            false
+        }
+    }
+}
+
+impl PartialEq<Vec<u8>> for Value {
+    fn eq(&self, other: &Vec<u8>) -> bool {
+        if let Value::ByteString(x) = self {
+            x == other
+        } else {
+            false
+        }
+    }
+}
+
+impl PartialEq<bool> for Value {
+    fn eq(&self, other: &bool) -> bool {
+        if let Value::Boolean(x) = self {
+            x == other
+        } else {
+            false
+        }
+    }
+}
+
+impl std::cmp::Eq for Value {
+}
+
 static FLOAT_DIVISOR: LazyLock<f64> = LazyLock::new(|| (256_f64).ln());
 
 fn write_packed_int( x: i64 ) -> Vec<u8>
@@ -154,15 +194,149 @@ impl Value {
         Ok(())
     }
 
-    pub fn write_packet<W: Write>( &self, w: &mut W ) -> Result<(), std::io::Error> {
+    fn read_parse<R: Read>(r: &mut R) -> Result<ValueParse, std::io::Error> {
+        let it = {
+            let mut it = [0u8];
+            r.read_exact( &mut it )?;
+            it[0]
+        };
+        match it as char {
+            '0' => Ok(ValueParse::Value(Value::Boolean(false))),
+            '1' => Ok(ValueParse::Value(Value::Boolean(true))),
+            'n' => Ok(ValueParse::Value(Value::Nothing)),
+            'e' => Ok(ValueParse::EndMarker),
+            'i' => Ok(ValueParse::Value(Value::Integer(read_packed_int(r)?))),
+            's' => {
+                let len = read_packed_int(r)?;
+                let mut body = vec![0; len as usize];
+                r.read_exact( &mut body )?;
+                Ok(ValueParse::Value(Value::ByteString(body)))
+            }
+            'l' => {
+                let mut body = Vec::<Value>::new();
+                loop {
+                    match Value::read_parse(r)? {
+                        ValueParse::Value(v) => body.push(v),
+                        ValueParse::EndMarker => break,
+                    }
+                }
+                Ok(ValueParse::Value(Value::List(body)))
+            }
+            'f' => {
+                let (lng, neg) = {
+                    let lng = read_packed_int( r )?;
+                    if lng < 0 {
+                        (-lng, true)
+                    } else {
+                        (lng, false)
+                    }
+                };
+                let mut value = 0.0f64;
+                let mut buf = vec![0u8; lng as usize];
+                r.read_exact( &mut buf )?;
+                for b in buf[1..].iter().rev() {
+                    value = (value+(*b as f64))*(1.0/256.0);
+                }
+                value += buf[0] as f64;
+                let scale = read_packed_int( r )?;
+                value *= 256.0f64.powi( scale as i32 );
+                if neg {
+                    Ok(ValueParse::Value(Value::Float(-value)))
+                } else {
+                    Ok(ValueParse::Value(Value::Float(value)))
+                }
+            }
+            'F' => {
+                let st = {
+                    let mut st = [0u8];
+                    r.read_exact( &mut st )?;
+                    st[0]
+                };
+                match st as char {
+                    'N' => Ok(ValueParse::Value(Value::Float(f64::NAN))),
+                    'n' => Ok(ValueParse::Value(Value::Float(f64::NAN))),
+                    'I' => Ok(ValueParse::Value(Value::Float(f64::NEG_INFINITY))),
+                    'i' => Ok(ValueParse::Value(Value::Float(f64::INFINITY))),
+                    'Z' => Ok(ValueParse::Value(Value::Float(-0.0f64))),
+                    'z' => Ok(ValueParse::Value(Value::Float(0.0f64))),
+                    _ => {
+                        return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Unknown exceptional float subtype found."));
+                    }
+                }
+            }
+            'd' => {
+                let mut body = HashMap::new();
+                loop {
+                    let k = match Value::read_parse(r)? {
+                        ValueParse::Value(v) => {
+                            if let Value::ByteString(s) = v {
+                                if let Ok(s) = String::from_utf8(s) {
+                                    s
+                                } else {
+                                    return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Keys must be utf8 compatbile strings."));
+                                }
+                            } else {
+                                return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Non-string cannot be dictionary key."));
+                            }
+                        },
+                        ValueParse::EndMarker => break,
+                    };
+                    let v = match Value::read_parse(r)? {
+                        ValueParse::Value(v) => v,
+                        ValueParse::EndMarker => {
+                            return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Premature end marker in dictionary."));
+                        }
+                    };
+                    body.insert( k, v );
+                }
+                Ok(ValueParse::Value(Value::Dictionary(body)))
+            }
+            _ => {
+                Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Invalid data type specified."))
+            }
+        }
+    }
+    
+    pub fn read<R: Read>(r: &mut R) -> Result<Value, std::io::Error> {
+        match Value::read_parse(r) {
+            Ok(ValueParse::Value(v)) => Ok(v),
+            Ok(ValueParse::EndMarker) => Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Unexpecetd EndMarker while parsing structure.")),
+            Err(e) => Err(e)
+        }
+    }
+
+    pub fn to_packet( &self ) -> Result<Vec<u8>, std::io::Error> {
         let mut body : Vec<u8> = vec![1u8,0u8,0u8,0u8,0u8];
         self.write( &mut body )?;
         let len = body.len() as u32;
         body[1..5].copy_from_slice( &len.to_be_bytes() );
-        w.write_all( &body )
+        Ok(body)
     }
 
+    pub fn write_packet<W: Write>( &self, w: &mut W ) -> Result<(), std::io::Error> {
+        match self.to_packet() {
+            Ok(body) => {
+                w.write_all( &body )
+            }
+            Err(e) => {
+                Err(e)
+            }
+        }
+    }
 
+    pub fn from_packet<R: Read>( r: &mut R ) -> Result<Value, std::io::Error> {
+        let mut ver = [0u8];
+        let mut size = [0u8; 4];
+        r.read_exact( &mut ver )?;
+        if ver[0] != 1 {
+            return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Invalid gats packet version."));
+        }
+        r.read_exact( &mut size )?;
+        let size = i32::from_be_bytes( size );
+        let mut buf = vec![0u8; size as usize -5];
+        r.read_exact( &mut buf )?;
+        Ok(Value::read( &mut Cursor::new( buf ) )?)
+    }
 }
 
 #[cfg(test)]
@@ -170,7 +344,7 @@ mod tests {
     use super::*;
     use core::error::Error;
     use std::fs::File;
-    use std::io::prelude::*;
+    use std::io::Cursor;
 
     #[test]
     fn write_file1() -> Result<(),Box<dyn Error>> {
@@ -187,7 +361,112 @@ mod tests {
             ("null".to_string(), Value::Nothing),
             ("float".to_string(), Value::Float(123.456)),
         ]));
-        v.write_packet( &mut f );
+        v.write_packet( &mut f )?;
+        Ok(())
+    }
+
+    #[test]
+    fn round_int() -> Result<(),Box<dyn Error>> {
+        let v = Value::Integer(555666);
+        let mut buf = Vec::<u8>::new();
+        v.write( &mut buf )?;
+        let v2 = Value::read( &mut Cursor::new(buf) )?;
+        assert!( v == v2 );
+        assert!( v == 555666 );
+        Ok(())
+    }
+
+    #[test]
+    fn round_str() -> Result<(),Box<dyn Error>> {
+        let v = Value::ByteString(vec![1,1,2,3,5,8,13,21,34]);
+        let mut buf = Vec::<u8>::new();
+        v.write( &mut buf )?;
+        let v2 = Value::read( &mut Cursor::new(buf) )?;
+        let v3 = Value::ByteString(vec![1,1,2,3,5,8,13,21,35]);
+        assert!( v == v2 );
+        assert!( v != v3 );
+        assert!( v == vec![1,1,2,3,5,8,13,21,34] );
+        Ok(())
+    }
+
+    #[test]
+    fn round_bool_true() -> Result<(),Box<dyn Error>> {
+        let v = Value::Boolean(true);
+        let mut buf = Vec::<u8>::new();
+        v.write( &mut buf )?;
+        let v2 = Value::read( &mut Cursor::new(buf) )?;
+        let v3 = Value::Boolean(false);
+        assert!( v == v2 );
+        assert!( v != v3 );
+        assert!( v == true );
+        Ok(())
+    }
+    
+    #[test]
+    fn round_bool_false() -> Result<(),Box<dyn Error>> {
+        let v = Value::Boolean(false);
+        let mut buf = Vec::<u8>::new();
+        v.write( &mut buf )?;
+        let v2 = Value::read( &mut Cursor::new(buf) )?;
+        let v3 = Value::Boolean(true);
+        assert!( v == v2 );
+        assert!( v != v3 );
+        assert!( v == false );
+        Ok(())
+    }
+
+    #[test]
+    fn round_list() -> Result<(),Box<dyn Error>> {
+        let v = Value::List(vec![
+            Value::Integer(1), Value::Integer(1), Value::Integer(2),
+            Value::Integer(3), Value::Integer(5), Value::Integer(8),
+            Value::Integer(13), Value::Integer(21), Value::Integer(34),
+        ]);
+        let mut buf = Vec::<u8>::new();
+        v.write( &mut buf )?;
+        let v2 = Value::read( &mut Cursor::new(buf) )?;
+        assert!( v == v2 );
+        Ok(())
+    }
+
+    #[test]
+    fn round_dictionary() -> Result<(), Box<dyn Error>> {
+        let v = Value::Dictionary(HashMap::from([
+            ("biggerint".to_string(), Value::Integer(98765)),
+            ("negint".to_string(), Value::Integer(-98765)),
+            ("integer".to_string(), Value::Integer(44)),
+            ("boolean".to_string(), Value::Boolean(true)),
+            ("list".to_string(), Value::List(vec![
+                Value::Integer(1), Value::Integer(1), Value::Integer(2),
+                Value::Integer(3), Value::Integer(5), Value::Integer(8),
+            ])),
+            ("null".to_string(), Value::Nothing),
+            ("float".to_string(), Value::Float(123.456)),
+        ]));
+        let mut buf = Vec::<u8>::new();
+        v.write( &mut buf )?;
+        let v2 = Value::read( &mut Cursor::new(buf) )?;
+        assert!( v == v2 );
+        Ok(())
+    }
+
+    #[test]
+    fn round_null() -> Result<(), Box<dyn Error>> {
+        let v = Value::Nothing;
+        let mut buf = Vec::<u8>::new();
+        v.write( &mut buf )?;
+        let v2 = Value::read( &mut Cursor::new(buf) )?;
+        assert!( v == v2 );
+        Ok(())
+    }
+
+    #[test]
+    fn round_float() -> Result<(), Box<dyn Error>> {
+        let v = Value::Float(123.456);
+        let mut buf = Vec::<u8>::new();
+        v.write( &mut buf )?;
+        let v2 = Value::read( &mut Cursor::new(buf) )?;
+        assert!( v == v2 );
         Ok(())
     }
 }