logger fixes

core/print.c

@@ -430,13 +430,39 @@ static const char* const log_level_colors[] = {
     [LOG_PANIC] = "\e[1;31m",
 };
 
-static void log_console_printf(const char* fmt, ...) {
+static void log_cb_printf(log_fn_t callback, void* ctx, const char* fmt, ...) {
     va_list args;
     va_start(args, fmt);
-    print_fmt(printf_console, nullptr, fmt, args);
+    print_fmt(callback, ctx, fmt, args);
     va_end(args);
 }
 
+// Formats a single record and passes it to `callback`.
+static void log_emit(log_fn_t callback, void* ctx, const struct log_record* rec, const char* msg) {
+    log_cb_printf(
+        callback,
+        ctx,
+        "[%5lu.%06lu] [%5lu] %s",
+        rec->time_ns / 1'000'000'000,
+        rec->time_ns / 1'000 % 1'000'000,
+        (uint64_t)rec->tid,
+        log_level_colors[rec->level]
+    );
+    callback(ctx, msg, rec->len);
+    callback(ctx, "\e[0m\n", 5);
+}
+
+void log_replay(log_fn_t callback, void* ctx) {
+    char msg[LOG_MESSAGE_MAX];
+    for (size_t offset = log_tail; offset != log_head;) {
+        struct log_record rec;
+        log_ring_peek(offset, &rec, sizeof(rec));
+        log_ring_peek(offset + sizeof(rec), msg, rec.len);
+        log_emit(callback, ctx, &rec, msg);
+        offset += sizeof(rec) + rec.len;
+    }
+}
+
 void log_vwrite(enum log_level level, const char* message, va_list args) {
     log_vwrite_prefixed(level, "", message, args);
 }
@@ -458,15 +484,7 @@ void log_vwrite_prefixed(enum log_level level, const char* prefix, const char* m
 
     spin_lock(&print_lock);
     log_store(&rec, line.buf);
-    log_console_printf(
-        "[%5lu.%06lu] [%5lu] %s",
-        rec.time_ns / 1'000'000'000,
-        rec.time_ns / 1'000 % 1'000'000,
-        (uint64_t)rec.tid,
-        log_level_colors[level]
-    );
-    console_write(line.buf, line.len);
-    console_write("\e[0m\n", 5);
+    log_emit(printf_console, nullptr, &rec, line.buf);
     spin_unlock(&print_lock);
 }