v0.26.3 web viewer improvement

internal/core/flow.go

@@ -2,6 +2,7 @@ package core
 
 import (
 	"encoding/json"
+	"strings"
 	"time"
 )
 
@@ -24,3 +25,41 @@ type TransportEvent struct {
 	// Structured entry for re-serializing sinks (chain links). Zero Time => absent
 	Entry LogEntry
 }
+
+// Levels are the entry levels by rising severity, each with the words naming
+// it in a line: the sources, the console sink's painter and the viewer share them
+var Levels = []struct {
+	Level string   `json:"level"`
+	Names []string `json:"names"`
+}{
+	{"TRACE", []string{"TRACE"}},
+	{"DEBUG", []string{"DEBUG", "DBG"}},
+	{"INFO", []string{"INFO", "INF"}},
+	{"WARN", []string{"WARN", "WARNING"}},
+	{"ERROR", []string{"ERROR", "ERR", "FATAL"}},
+}
+
+// LevelWord finds the first whole word of text, in any case, that names a
+// level, or names want when it is set; it returns the level and the word's
+// bounds, and "" when no word does.
+func LevelWord[T string | []byte](text T, want string) (level string, start, end int) {
+	for i := 0; i < len(text); i = end {
+		for i < len(text) && !wordByte(text[i]) {
+			i++
+		}
+		for end = i; end < len(text) && wordByte(text[end]); end++ {
+		}
+		for _, l := range Levels {
+			for _, name := range l.Names {
+				if end-i == len(name) && (want == "" || want == l.Level) && strings.EqualFold(string(text[i:end]), name) {
+					return l.Level, i, end
+				}
+			}
+		}
+	}
+	return "", 0, 0
+}
+
+func wordByte(c byte) bool {
+	return c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c >= '0' && c <= '9' || c == '_'
+}

internal/core/flow_test.go

@@ -0,0 +1,24 @@
+package core
+
+import "testing"
+
+// A line's level is its first whole word, in any case, naming a level, not the
+// most severe one named; a wanted level skips the names of the others.
+func TestLevelIsTheFirstWordNamingOne(t *testing.T) {
+	for _, c := range []struct {
+		text, want, level string
+		start, end        int
+	}{
+		{"warning disk full", "", "WARN", 0, 7},
+		{"DBG x", "", "DEBUG", 0, 3},
+		{"2026-10-05 [Info] retry after error", "", "INFO", 12, 16},
+		{`{"level":"fatal","msg":"x"}`, "", "ERROR", 10, 15},
+		{"terror informal x_ERR", "", "", 0, 0},
+		{"INFO then ERR", "ERROR", "ERROR", 10, 13},
+	} {
+		level, start, end := LevelWord(c.text, c.want)
+		if level != c.level || start != c.start || end != c.end {
+			t.Errorf("%q want %q: got %q [%d:%d], want %q [%d:%d]", c.text, c.want, level, start, end, c.level, c.start, c.end)
+		}
+	}
+}