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use crate::{errors::ProtocolError, protocol::{Header, MessageType, ReplyData, RequestData}}; use crate::encoding::{ToBytes, FromBytes}; pub trait Transport { fn read(&mut self) -> std::io::Result<&[u8]>; fn write(&mut self, buf: &[u8]) -> std::io::Result<usize>; fn read_message(&mut self) -> Result<MessageType, Box<dyn std::error::Error>> { let buffer = self.read()?; let bytes = buffer.len(); let mut read: i32 = 0; let header = Header::from_bytes(&buffer[read as usize..bytes], &mut read)?; match header.message_type { 2 => { let reply = ReplyData::from_bytes(&buffer[read as usize..bytes as usize], &mut read)?; Ok(MessageType::Reply(header, reply)) } 3 => Ok(MessageType::ValidateConnection(header)), _ => Err(Box::new(ProtocolError::new(&format!("TCP: Unsuppored reply message type: {}", header.message_type)))) } } fn validate_connection(&mut self) -> Result<(), Box<dyn std::error::Error>> { let header = Header::new(0, 14); let mut bytes = header.to_bytes()?; let written = self.write(&mut bytes)?; if written != header.message_size as usize { return Err(Box::new(ProtocolError::new("TCP: Could not validate connection"))) } Ok(()) } fn close_connection(&mut self) -> Result<(), Box<dyn std::error::Error>> { let header = Header::new(4, 14); let mut bytes = header.to_bytes()?; let written = self.write(&mut bytes)?; if written != header.message_size as usize { return Err(Box::new(ProtocolError::new("TCP: Could not validate connection"))) } Ok(()) } fn make_request(&mut self, request: &RequestData) -> Result<(), Box<dyn std::error::Error>> { let req_bytes = request.to_bytes()?; let header = Header::new(0, 14 + req_bytes.len() as i32); let mut bytes = header.to_bytes()?; bytes.extend(req_bytes); let written = self.write(&mut bytes)?; if written != header.message_size as usize { return Err(Box::new(ProtocolError::new(&format!("TCP: Error writing request {}", request.request_id)))) } Ok(()) } }