1 files changed, 92 insertions, 45 deletions

diff --git a/rust/src/lib.rs b/rust/src/lib.rs
index 300fa99..5a5f96a 100644
--- a/rust/src/lib.rs
+++ b/rust/src/lib.rs
@@ -1,9 +1,8 @@
 use std::collections::HashMap;
 use std::vec::Vec;
-use std::io::{Write,Read};
+use std::io::{Write,Read,Cursor,Error,ErrorKind};
 use std::num::FpCategory;
 use std::sync::LazyLock;
-use std::io::Cursor;
 
 #[derive(PartialEq)]
 pub enum Value {
@@ -16,7 +15,12 @@ pub enum Value {
     Nothing,
 }
 
-pub enum ValueParse {
+pub enum BytesToRead {
+    Estimate(usize),
+    Final(usize),
+}
+
+enum ValueParse {
     Value(Value),
     EndMarker,
 }
@@ -77,7 +81,7 @@ fn write_packed_int( x: i64 ) -> Vec<u8>
     w
 }
 
-fn read_packed_int<R: Read>( r: &mut R ) -> Result<i64, std::io::Error> {
+fn read_packed_int<R: Read>( r: &mut R ) -> Result<i64, Error> {
     let mut out : i64;
     let mut bb = [0u8];
     r.read( &mut bb )?;
@@ -98,7 +102,7 @@ fn read_packed_int<R: Read>( r: &mut R ) -> Result<i64, std::io::Error> {
 }
 
 impl Value {
-    pub fn write<W: Write>(&self, w: &mut W) -> Result<(), std::io::Error> {
+    pub fn write<W: Write>(&self, w: &mut W) -> Result<(), Error> {
         match self {
             Self::Integer(x) => {
                 let bb = ['i' as u8];
@@ -194,7 +198,7 @@ impl Value {
         Ok(())
     }
 
-    fn read_parse<R: Read>(r: &mut R) -> Result<ValueParse, std::io::Error> {
+    fn read_parse<R: Read>(r: &mut R) -> Result<ValueParse, Error> {
         let it = {
             let mut it = [0u8];
             r.read_exact( &mut it )?;
@@ -260,7 +264,7 @@ impl Value {
                     '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."));
+                        return Err(Error::new(ErrorKind::InvalidData, "Unknown exceptional float subtype found."));
                     }
                 }
             }
@@ -273,10 +277,10 @@ impl Value {
                                 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."));
+                                    return Err(Error::new(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."));
+                                return Err(Error::new(ErrorKind::InvalidData, "Non-string cannot be dictionary key."));
                             }
                         },
                         ValueParse::EndMarker => break,
@@ -284,7 +288,7 @@ impl Value {
                     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."));
+                            return Err(Error::new(ErrorKind::InvalidData, "Premature end marker in dictionary."));
                         }
                     };
                     body.insert( k, v );
@@ -292,20 +296,20 @@ impl Value {
                 Ok(ValueParse::Value(Value::Dictionary(body)))
             }
             _ => {
-                Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Invalid data type specified."))
+                Err(Error::new(ErrorKind::InvalidData, "Invalid data type specified."))
             }
         }
     }
     
-    pub fn read<R: Read>(r: &mut R) -> Result<Value, std::io::Error> {
+    pub fn read<R: Read>(r: &mut R) -> Result<Value, 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.")),
+            Ok(ValueParse::EndMarker) => Err(Error::new(ErrorKind::InvalidData, "Unexpecetd EndMarker while parsing structure.")),
             Err(e) => Err(e)
         }
     }
 
-    pub fn to_packet( &self ) -> Result<Vec<u8>, std::io::Error> {
+    pub fn to_packet( &self ) -> Result<Vec<u8>, Error> {
         let mut body : Vec<u8> = vec![1u8,0u8,0u8,0u8,0u8];
         self.write( &mut body )?;
         let len = body.len() as u32;
@@ -313,7 +317,7 @@ impl Value {
         Ok(body)
     }
 
-    pub fn write_packet<W: Write>( &self, w: &mut W ) -> Result<(), std::io::Error> {
+    pub fn write_packet<W: Write>( &self, w: &mut W ) -> Result<(), Error> {
         match self.to_packet() {
             Ok(body) => {
                 w.write_all( &body )
@@ -324,18 +328,60 @@ impl Value {
         }
     }
 
-    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."));
+    pub fn bytes_to_read( r: &[u8] ) -> Result<BytesToRead, Error> {
+        if r.len() < 5 {
+            Ok(BytesToRead::Estimate(5))
+        } else {
+            if r[0] != 1 {
+                return Err(Error::new(ErrorKind::InvalidData, "Invalid gats packet version."));
+            }
+            if let Ok(ar) = r[1..5].try_into() {
+                Ok(BytesToRead::Final(i32::from_be_bytes( ar ) as usize))
+            } else {
+                Err(Error::new(ErrorKind::UnexpectedEof, "Insufficient data presented to decode packet header."))
+            }
+        }
+    }
+
+    pub fn from_packet( r: &[u8] ) -> Result<Value, Error> {
+        if r.len() < 5 {
+            return Err(Error::new(ErrorKind::UnexpectedEof, "Insufficient data presented to decode packet header."));
+        }
+        if r[0] != 1 {
+            return Err(Error::new(ErrorKind::InvalidData, "Invalid gats packet version."));
+        }
+        let size = if let Ok(ar) = r[1..5].try_into() {
+            i32::from_be_bytes( ar )
+        } else {
+            return Err(Error::new(ErrorKind::UnexpectedEof, "Insufficient data presented to decode packet header."));
+        };
+        if r.len() != size as usize {
+            return Err(Error::new(ErrorKind::InvalidData, "Packet buffer is the wrong length."));
+        }
+        Ok(Value::read( &mut Cursor::new( &r[5..] ) )?)
+    }
+
+    pub fn read_packet<R: Read>( r: &mut R ) -> Result<Value,Error> {
+        let mut buf = Vec::<u8>::new();
+        let mut fill = 0usize;
+        loop {
+            match Value::bytes_to_read( &buf ) {
+                Ok(BytesToRead::Estimate(size)) => {
+                    buf.resize(size, 0u8);
+                    r.read_exact( &mut buf[fill..] )?;
+                    fill = buf.len();
+                }
+                Ok(BytesToRead::Final(size)) => {
+                    buf.resize(size, 0u8);
+                    r.read_exact( &mut buf[fill..] )?;
+                    //fill = buf.len();
+                    return Value::from_packet( &buf );
+                }
+                Err(e) => {
+                    return Err(e);
+                }
+            }
         }
-        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 ) )?)
     }
 }
 
@@ -347,25 +393,6 @@ mod tests {
     use std::io::Cursor;
 
     #[test]
-    fn write_file1() -> Result<(),Box<dyn Error>> {
-        let mut f = File::create("test.gats")?;
-        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)),
-        ]));
-        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();
@@ -469,4 +496,24 @@ mod tests {
         assert!( v == v2 );
         Ok(())
     }
+
+    #[test]
+    fn packet_1() -> 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 buf = v.to_packet()?;
+        let v2 = Value::from_packet( &buf )?;
+        assert!( v == v2 );
+        Ok(())
+    }
 }