handle multiple "equal" matches

data/src/types.rs

@@ -46,6 +46,23 @@ pub struct LoggingStatement {
     pub regex: &'static str,
 }
 
+impl Display for LoggingStatement {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        if let Some(exception) = self.exception {
+            write!(
+                f,
+                "{}({}): {} line {}",
+                exception,
+                self.message(),
+                self.path,
+                self.line
+            )
+        } else {
+            write!(f, "{}: {} line {}", self.message(), self.path, self.line)
+        }
+    }
+}
+
 impl LoggingStatement {
     pub fn message(&self) -> impl Display + '_ {
         LoggingMessage { message: &self }

src/main.rs

@@ -1,7 +1,7 @@
 use crate::error::LogError;
 use crate::logfile::LogFile;
 use crate::logline::LogLine;
-use crate::matcher::Matcher;
+use crate::matcher::{MatchResult, Matcher};
 use clap::Parser;
 use cloud_log_analyser_data::{get_statements, MAX_VERSION};
 use main_error::MainResult;
@@ -28,7 +28,7 @@ fn main() -> MainResult {
     })?;
     let mut lines = log_file.iter();
 
-    let mut counts: HashMap<usize, usize> = HashMap::new();
+    let mut counts: HashMap<MatchResult, usize> = HashMap::new();
     let first = lines.next().unwrap();
     let first_parsed: LogLine = serde_json::from_str(&first).unwrap();
 
@@ -66,26 +66,8 @@ fn main() -> MainResult {
     let mut counts: Vec<(_, _)> = counts.into_iter().collect();
     counts.sort_by_key(|(_, count)| *count);
     counts.reverse();
-    for (index, count) in counts {
-        let statement = &statements[index];
-        if let Some(exception) = statement.exception {
-            println!(
-                "{}({}): {} line {}: {}",
-                exception,
-                statement.message(),
-                statement.path,
-                statement.line,
-                count
-            );
-        } else {
-            println!(
-                "{}: {} line {}: {}",
-                statement.message(),
-                statement.path,
-                statement.line,
-                count
-            );
-        }
+    for (match_result, count) in counts {
+        println!("{}: {}", match_result.display(statements), count);
     }
     if unmatched_total > 0 {
         eprintln!("\n{unmatched_total} lines couldn't be matched:");

src/matcher.rs

@@ -1,6 +1,7 @@
 use crate::logline::LogLine;
 use cloud_log_analyser_data::{LogLevel, LoggingStatement};
 use regex::Regex;
+use std::fmt::{Display, Formatter};
 
 pub struct LogMatch {
     level: LogLevel,
@@ -39,7 +40,7 @@ impl Matcher {
         }
     }
 
-    pub fn match_log(&self, log: &LogLine) -> Option<usize> {
+    pub fn match_log(&self, log: &LogLine) -> Option<MatchResult> {
         let mut best_match = None;
         let mut best_length = 0;
 
@@ -49,7 +50,7 @@ impl Matcher {
                     && log_match.exception.as_deref() == Some(exception.exception.as_ref())
                     && log_match.path == exception.file.as_ref()
                 {
-                    return Some(i);
+                    return Some(MatchResult::Single(i));
                 }
             }
         }
@@ -58,10 +59,20 @@ impl Matcher {
             if log_match.has_meaningful_message {
                 if log.level.matches(log_match.level)
                     && log_match.pattern.is_match(log.message.as_ref())
-                    && log_match.pattern_length > best_length
+                    && log_match.pattern_length >= best_length
                 {
-                    best_match = Some(i);
-                    best_length = log_match.pattern_length;
+                    if log_match.pattern_length > best_length {
+                        best_match = None;
+                        best_length = log_match.pattern_length;
+                    }
+                    best_match = Some(match best_match {
+                        Some(MatchResult::Single(res)) => MatchResult::List(vec![res, i]),
+                        Some(MatchResult::List(mut list)) => {
+                            list.push(i);
+                            MatchResult::List(list)
+                        }
+                        None => MatchResult::Single(i),
+                    });
                 }
             }
         }
@@ -72,6 +83,49 @@ impl Matcher {
     }
 }
 
+#[derive(Debug, Clone, Eq, PartialEq, Hash)]
+pub enum MatchResult {
+    Single(usize),
+    List(Vec<usize>),
+}
+
+impl MatchResult {
+    pub fn display<'a>(&'a self, log_statements: &'a [LoggingStatement]) -> impl Display + 'a {
+        MatchResultDisplay {
+            log_statements,
+            result: &self,
+        }
+    }
+}
+
+struct MatchResultDisplay<'a> {
+    log_statements: &'a [LoggingStatement],
+    result: &'a MatchResult,
+}
+
+impl Display for MatchResultDisplay<'_> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        match self.result {
+            MatchResult::Single(index) => {
+                if let Some(statement) = self.log_statements.get(*index) {
+                    write!(f, "{statement}")
+                } else {
+                    write!(f, "unknown statement")
+                }
+            }
+            MatchResult::List(list) => {
+                writeln!(f, "{} possible matches:", list.len())?;
+                for index in list {
+                    if let Some(statement) = self.log_statements.get(*index) {
+                        writeln!(f, "  {statement}")?;
+                    }
+                }
+                write!(f, "    ")
+            }
+        }
+    }
+}
+
 #[test]
 fn test_matcher() {
     use crate::logline::Exception;