feat: add log level conversion

Author: c-git

README.md

@@ -3,12 +3,15 @@
 Simple log viewer.
 Works with log that have json on each line.
 Works in both Web (WASM) and on native.
+Defaults are configured for [bunyan formatted logs](https://github.com/trentm/node-bunyan) but these are setup as setting and are able to be changed (UI not implemented to change at present due to no demand).
+For rust programs one can use the crate [tracing_bunyan_formatter](https://docs.rs/tracing-bunyan-formatter/latest/tracing_bunyan_formatter/) to generate logs as done in the book [Zero To Production In Rust](https://www.zero2prod.com/index.html).
 
 You can use the deployed version without install at <https://c-git.github.io/log-viewer/>
 
 # Description of expected log file format
 
 It is expected that the file will contain multiple json objects separated by new lines.
+If a line is not valid json it can be converted into a Log record with the entire line being one json field.
 See [samples](tests/sample_logs/).
 A toy example would be:
 
@@ -20,7 +23,8 @@ A toy example would be:
 
 # How to run
 
-Make sure you are using the latest version of stable rust by running `rustup update`.
+We do not test on older version of rust so it is possible you may get compilation errors if you are not on the latest version of stable rust.
+To get the most recent stable version use `rustup update`.
 
 ## Native
 

src/app/data.rs

@@ -11,7 +11,7 @@ use serde_json::Value;
 
 use super::{
     calculate_hash,
-    data_display_options::{DataDisplayOptions, RowParseErrorHandling},
+    data_display_options::{DataDisplayOptions, LevelConversion, RowParseErrorHandling},
 };
 mod data_iter;
 pub mod filter;
@@ -393,10 +393,52 @@ impl TryFrom<(&DataDisplayOptions, usize, &str)> for LogRow {
         if let Some(key) = data_display_options.row_idx_field_name.as_ref() {
             result.or_insert(key.to_string(), row_idx_val.into());
         }
+        if let Some(settings) = data_display_options.level_conversion.as_ref() {
+            if let Some((key, value)) = level_conversion_to_display(&result, settings) {
+                result.or_insert(key, value);
+            }
+        }
         Ok(result)
     }
 }
 
+fn level_conversion_to_display(
+    row: &LogRow,
+    settings: &LevelConversion,
+) -> Option<(String, Value)> {
+    let FieldContent::Present(raw_value) = row.field_value(&settings.source_field_name) else {
+        return None;
+    };
+    let raw_value = match raw_value.as_i64() {
+        Some(x) => x,
+        None => {
+            warn!(
+                "Failed to convert raw for {:?} to i64: {raw_value:?}",
+                settings.source_field_name
+            );
+            debug_assert!(
+                false,
+                "This is not expected to happen. Unable to convert level to string slice"
+            );
+            return None;
+        }
+    };
+    match settings.convert_map.get(&raw_value) {
+        Some(converted_value) => Some((
+            settings.display_field_name.clone(),
+            converted_value.clone().into(),
+        )),
+        None => {
+            warn!("Failed to convert raw_value to a displayable log level: {raw_value:?}");
+            debug_assert!(
+                false,
+                "This is not expected to happen. Unable to convert level to a corresponding display value"
+            );
+            None
+        }
+    }
+}
+
 impl TryFrom<(&DataDisplayOptions, &str)> for Data {
     type Error = anyhow::Error;
 

src/app/data_display_options.rs

@@ -1,4 +1,4 @@
-use std::collections::BTreeSet;
+use std::collections::{BTreeMap, BTreeSet};
 
 #[derive(serde::Deserialize, serde::Serialize, Debug, PartialEq, Eq)]
 #[serde(default)] // if we add new fields, give them default values when deserializing old state
@@ -13,11 +13,14 @@ pub struct DataDisplayOptions {
     /// WARNING: This must be a valid index into the list as this is assumed in method implementations
     emphasize_if_matching_field_idx: Option<usize>,
 
-    /// When set adds a field with this name and populates it with the row numbers
+    /// When set adds a field with this name and populates it with the row numbers (Skips record if field name already exists)
     pub row_idx_field_name: Option<String>,
 
     /// Controls how errors during file loading are treated
     pub row_parse_error_handling: RowParseErrorHandling,
+
+    /// Used for optionally converting message levels to strings
+    pub level_conversion: Option<LevelConversion>,
 }
 
 #[derive(serde::Deserialize, serde::Serialize, Debug, PartialEq, Eq)]
@@ -30,6 +33,15 @@ pub enum RowParseErrorHandling {
     },
 }
 
+#[derive(serde::Deserialize, serde::Serialize, Debug, PartialEq, Eq)]
+pub struct LevelConversion {
+    /// Skips record if field name already exists
+    pub display_field_name: String,
+    /// Skips conversion if source field cannot be found
+    pub source_field_name: String,
+    pub convert_map: BTreeMap<i64, String>,
+}
+
 impl DataDisplayOptions {
     pub fn main_list_fields(&self) -> &[String] {
         &self.main_list_fields
@@ -46,10 +58,17 @@ impl Default for DataDisplayOptions {
     fn default() -> Self {
         Self {
             // TODO 3: Add ability to show, select and reorder selected fields
-            main_list_fields: ["row#", "time", "request_id", "otel.name", "msg"]
-                .into_iter()
-                .map(String::from)
-                .collect(),
+            main_list_fields: [
+                "row#",
+                "level_str",
+                "time",
+                "request_id",
+                "otel.name",
+                "msg",
+            ]
+            .into_iter()
+            .map(String::from)
+            .collect(),
             common_fields: [
                 "elapsed_milliseconds",
                 "file",
@@ -79,6 +98,7 @@ impl Default for DataDisplayOptions {
             emphasize_if_matching_field_idx: Some(2),
             row_idx_field_name: Some("row#".to_string()),
             row_parse_error_handling: Default::default(),
+            level_conversion: Some(Default::default()),
         }
     }
 }
@@ -91,3 +111,24 @@ impl Default for RowParseErrorHandling {
         }
     }
 }
+
+impl Default for LevelConversion {
+    fn default() -> Self {
+        // See bunyan levels https://github.com/trentm/node-bunyan?tab=readme-ov-file#levels and note rust only goes up to Error
+        let convert_map = vec![
+            (60, "Fatal".to_string()),
+            (50, "Error".to_string()),
+            (40, "Warn".to_string()),
+            (30, "Info".to_string()),
+            (20, "Debug".to_string()),
+            (10, "Trace".to_string()),
+        ]
+        .into_iter()
+        .collect();
+        Self {
+            display_field_name: "level_str".into(),
+            source_field_name: "level".into(),
+            convert_map,
+        }
+    }
+}