fix reader & searcher

1. fix
find_offset_to_start(#146)
2. fix
read_metrics_one_file_by_end_time(#145)

Author: flearc

sentinel-core/Cargo.toml

@@ -70,6 +70,7 @@ schemars = { version = "0.8.8", optional = true }
 apollo-client = { version = "0.7.5", optional = true }
 futures-util = { version = "0.3.29", optional = true }
 dirs = "5.0.1"
+byteorder = "1.5.0"
 
 [target.'cfg(not(target_arch="wasm32"))'.dependencies]
 # cannot add "wasm-bindgen" feature to uuid, 

sentinel-core/src/core/log/metric/reader.rs

@@ -85,38 +85,36 @@ impl DefaultMetricLogReader {
         let end_sec = end_ms / 1000;
         let file = open_file_and_seek_to(filename, offset)?;
 
-        let mut buf_reader = BufReader::new(file);
+        let buf_reader = BufReader::new(file);
         let mut items = Vec::with_capacity(1024);
-        loop {
-            let mut line = String::new();
-            let count = buf_reader.read_line(&mut line)?;
-            if count == 0 {
-                return Ok((Vec::new(), true));
-            }
-            let item = base::MetricItem::from_string(&line);
-            match item {
-                Ok(item) => {
-                    let ts_sec = item.timestamp / 1000;
-                    // current_second should in [begin_sec, end_sec]
-                    if ts_sec < begin_sec || ts_sec > end_sec {
-                        return Ok((items, false));
-                    }
 
-                    // empty resource name indicates "fetch all"
-                    if resource.is_empty() || resource == &item.resource {
-                        items.push(item);
-                    }
+        let lines = buf_reader.lines();
 
-                    if prev_size + items.len() >= MAX_ITEM_AMOUNT {
-                        return Ok((items, false));
-                    }
-                }
+        for line in lines {
+            let line = line?;
+            let item = match base::MetricItem::from_string(&line) {
+                Ok(item) => item,
                 Err(err) => {
-                    logging::error!("DefaultMetricLogReader::read_metrics_one_file_by_end_time: {:?} Failed to convert to MetricItem. Error: {:?}.", line,err);
+                    logging::error!("Failed to convert to MetricItem: {:?}", err);
                     continue;
                 }
+            };
+
+            let ts_time = item.timestamp / 1000;
+            if ts_time < begin_sec || ts_time > end_sec {
+                return Ok((items, false)); // Outside time range
+            }
+
+            if resource.is_empty() || resource == &item.resource {
+                items.push(item);
+            }
+
+            if prev_size + items.len() >= MAX_ITEM_AMOUNT {
+                return Ok((items, false)); // Reached maximum item amount
             }
         }
+
+        Ok((items, true)) // End of file
     }
 }
 

sentinel-core/src/core/log/metric/searcher.rs

@@ -1,7 +1,9 @@
+use byteorder::{BigEndian, ReadBytesExt};
+
 use super::*;
 use crate::{logging, Error, Result};
 use std::fs::File;
-use std::io::{Read, Seek, SeekFrom};
+use std::io::{Cursor, Read, Seek, SeekFrom};
 use std::sync::Mutex;
 #[derive(Debug)]
 pub struct FilePosition {
@@ -139,32 +141,32 @@ impl DefaultMetricSearcher {
         filename: &str,
         begin_time_ms: u64,
         last_pos: SeekFrom,
-    ) -> Result<u32> {
-        let mut cached_pos = self.cached_pos.lock().unwrap();
-        cached_pos.idx_filename = "".into();
-        cached_pos.metric_filename = "".into();
-
+    ) -> Result<u64> {
         let idx_filename = form_metric_idx_filename(filename);
         let begin_sec = begin_time_ms / 1000;
         let mut file = File::open(&idx_filename)?;
 
-        // Set position to the offset recorded in the idx file
-        cached_pos.cur_offset_in_idx = SeekFrom::Start(file.seek(last_pos)?);
-        let mut sec: u64;
-        loop {
-            let mut buffer: [u8; 8] = [0; 8];
-            file.read_exact(&mut buffer)?;
-            sec = u64::from_be_bytes(buffer);
+        let mut cached_pos = self.cached_pos.lock().unwrap();
+
+        // Seek to the last position
+        file.seek(last_pos)?;
+
+        let mut index_data = Vec::new();
+        file.read_to_end(&mut index_data)?;
+
+        let mut offset = 0;
+        let mut sec = 0;
+
+        let mut reader = Cursor::new(index_data);
+        while let Ok(sec_be) = ReadBytesExt::read_u64::<BigEndian>(&mut reader) {
+            sec = sec_be;
+            let offset_be = ReadBytesExt::read_u64::<BigEndian>(&mut reader)?;
+            offset = offset_be;
             if sec >= begin_sec {
                 break;
             }
-            let mut buffer: [u8; 4] = [0; 4];
-            file.read_exact(&mut buffer)?;
-            cached_pos.cur_offset_in_idx = SeekFrom::Start(file.seek(SeekFrom::Current(0))?);
         }
-        let mut buffer: [u8; 4] = [0; 4];
-        file.read_exact(&mut buffer)?;
-        let offset = u32::from_be_bytes(buffer);
+
         // Cache the idx filename and position
         cached_pos.metric_filename = filename.into();
         cached_pos.idx_filename = idx_filename.into();