stack sparkline

Cargo.toml

@@ -2,7 +2,7 @@
 name = "logsmash"
 version = "0.1.11"
 edition = "2021"
-rust-version = "1.85.0"
+rust-version = "1.87.0"
 license = "GPL-3.0-only"
 
 [dependencies]

src/app.rs

@@ -2,7 +2,7 @@ use crate::grouping::group_lines_by;
 use crate::logfile::{LogFile, LogLine, LogLineNumber};
 use crate::logs::ParsedLogs;
 use crate::matcher::MatchResult;
-use crate::timegraph::TimeGraph;
+use crate::timegraph::{SparkLine, TimeGraph};
 use logsmash_data::{LoggingStatementWithPathPrefix, StatementList};
 use regex::{escape, Regex, RegexBuilder};
 use serde_json::Error as JsonError;
@@ -56,7 +56,7 @@ pub struct LogMatch<'logs> {
     pub result: Option<MatchResult>,
     pub count: usize,
     pub histogram: OnceCell<TimeGraph>,
-    pub sparkline: OnceCell<String>,
+    pub sparkline: OnceCell<SparkLine>,
     pub all: LineSet<'logs>,
     pub grouped: Vec<LineSet<'logs>>,
 }
@@ -77,10 +77,9 @@ impl<'logs> LogMatch<'logs> {
         }
     }
 
-    pub fn sparkline(&self, app: &App) -> &str {
+    pub fn sparkline(&self, app: &App) -> &SparkLine {
         self.sparkline
-            .get_or_init(|| self.histogram(app).sparkline::<10>())
-            .as_str()
+            .get_or_init(|| self.histogram(app).sparkline())
     }
 
     pub fn histogram(&self, app: &App) -> &TimeGraph {
@@ -136,7 +135,7 @@ impl<'logs> LogMatch<'logs> {
 pub struct LineSet<'logs> {
     pub lines: Vec<&'logs LogLine<'logs>>,
     pub histogram: OnceCell<TimeGraph>,
-    pub sparkline: OnceCell<String>,
+    pub sparkline: OnceCell<SparkLine>,
 }
 
 impl<'logs> LineSet<'logs> {
@@ -148,10 +147,9 @@ impl<'logs> LineSet<'logs> {
         }
     }
 
-    pub fn sparkline(&self, app: &App) -> &str {
+    pub fn sparkline(&self, app: &App) -> &SparkLine {
         self.sparkline
-            .get_or_init(|| self.histogram(app).sparkline::<10>())
-            .as_str()
+            .get_or_init(|| self.histogram(app).sparkline())
     }
 
     pub fn histogram(&self, app: &App) -> &TimeGraph {

src/timegraph.rs

@@ -1,4 +1,5 @@
 use hdrhistogram::Histogram;
+use ratatui::text::Text;
 use std::cmp::max;
 use time::OffsetDateTime;
 
@@ -41,21 +42,44 @@ impl TimeGraph {
             .map(|val| val.count_since_last_iteration())
     }
 
-    pub fn sparkline<const N: usize>(&self) -> String {
-        let mut values = [0; N];
-        for (value, count) in values.iter_mut().zip(self.counts(N)) {
+    pub fn sparkline(&self) -> SparkLine {
+        let mut values = [0; 10];
+        for (value, count) in values.iter_mut().zip(self.counts(10)) {
             *value = count;
         }
         let max = values.iter().copied().max().unwrap_or_default() as f64;
         let len = SPARKS.len() as f64 - 1.0;
         values
-            .iter()
-            .copied()
             .map(|val| {
                 let rel = val as f64 / max;
                 SPARKS[(rel * len) as usize]
             })
-            .collect()
+            .into()
+    }
+}
+
+// the biggest sparkline char is 3 bytes
+pub struct SparkLine {
+    bytes: [u8; 10 * 3],
+}
+
+impl From<[char; 10]> for SparkLine {
+    fn from(value: [char; 10]) -> Self {
+        let mut buff = [0; 10 * 3];
+        let mut offset = 0;
+        for char in value {
+            char.encode_utf8(&mut buff[offset..]);
+            offset += char.len_utf8();
+        }
+        SparkLine { bytes: buff }
+    }
+}
+
+impl<'a> From<&'a SparkLine> for Text<'a> {
+    fn from(value: &'a SparkLine) -> Self {
+        // SAFETY: we only put bytes into the buffer from encode_utf8
+        let str = unsafe { str::from_utf8_unchecked(&value.bytes).trim_end_matches(char::from(0)) };
+        Text::raw(str)
     }
 }