异常处理

src/prehandle.rs

@@ -1,8 +1,9 @@
 use std::{io::Read, path::PathBuf};
 use std::fs::File;
 use std::io::{BufRead, BufReader, Cursor};
+use std::ptr::read;
 
-pub fn handle(path: PathBuf,filter_str:String, start_index: u32, end_index: u32) -> Box<dyn Read>{
+pub fn handle(path: PathBuf, filter_str:String, start_index: u32, end_index: u32) -> Box<dyn Read>{
     let reader = BufReader::new(File::open(path).unwrap());
     let mut lines = reader.lines().collect::<Result<Vec<_>, _>>().unwrap();
     lines = filter_by_string(lines, filter_str.as_str());
@@ -22,6 +23,9 @@ fn filter_by_string(reader: Vec<String>, filter_str: &str) ->Vec<String>{
 }
 
 fn take(reader: &mut Vec<String>, start_index: u32, end_index: u32) -> Vec<String> {
+    if end_index < 0 && start_index < 0{
+        panic!("start_index and end_index must be positive");
+    }
     if end_index == 0 && start_index == 0{
         return reader.to_owned();
     }
@@ -30,8 +34,10 @@ fn take(reader: &mut Vec<String>, start_index: u32, end_index: u32) -> Vec<Strin
     body.push(header);
     if end_index == 0{
         body.append(&mut reader[start_index as usize..].to_owned());
-    }else{
+    }else if(end_index < reader.len() as u32){
         body.append(&mut reader[start_index as usize..end_index as usize].to_owned());
+    }else {
+        body.append(&mut reader[start_index as usize..].to_owned());
     }
     body
 }