refactor: Wave 2 — LunarCache 可注入化 + 重复计算提取

- refactor: LunarCache 从 object 单例改为 class + Mutex，方法改为 suspend
- refactor: DayCell 参数注入 lunarCache，remember → produceState
- refactor: 提取 MonthGridInfo/getMonthGridInfo 到 CalendarUtils
- refactor: CalendarViewModel init 块和 getMonthDays 复用 getMonthGridInfo
- refactor: calculateWeeksCount 委托给 getMonthGridInfo

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

core/src/main/kotlin/plus/rua/project/CalendarViewModel.kt

@@ -23,6 +23,7 @@ import kotlinx.datetime.todayIn
 import plus.rua.project.LunarCache
 import plus.rua.project.ui.COLLAPSE_THRESHOLD
 import plus.rua.project.ui.FLING_VELOCITY_THRESHOLD_DP
+import plus.rua.project.ui.getMonthGridInfo
 import kotlin.time.Clock
 
 /**
@@ -64,26 +65,19 @@ class CalendarViewModel(
                 currentMonth to currentYear,
                 currentMonth + 1 to currentYear
             ).map { (month, year) ->
-                when {
+                val (normalizedMonth, normalizedYear) = when {
                     month < 1 -> 12 to year - 1
                     month > 12 -> 1 to year + 1
                     else -> month to year
                 }
+                getMonthGridInfo(normalizedYear, normalizedMonth)
             }
 
-            monthsToPrecompute.forEach { (month, year) ->
+            monthsToPrecompute.forEach { info ->
-                val firstOfMonth = LocalDate(year, month, 1)
+                val dates = (0 until info.totalDays).map { i ->
-                val offset = firstOfMonth.dayOfWeek.ordinal
+                    info.startDate.plus(DatePeriod(days = i))
-                val startDate = firstOfMonth.minus(DatePeriod(days = offset))
-                val nextMonth = if (month == 12) LocalDate(year + 1, 1, 1) else LocalDate(year, month + 1, 1)
-                val daysInMonth = nextMonth.minus(DatePeriod(days = 1)).day
-                val rows = ((offset + daysInMonth - 1) / 7) + 1
-                val totalDays = rows * 7
-
-                val dates = (0 until totalDays).map { i ->
-                    startDate.plus(DatePeriod(days = i))
                 }
-                LunarCache.precompute(dates)
+                LunarCache.default.precompute(dates)
             }
         }
     }
@@ -327,17 +321,9 @@ class CalendarViewModel(
     @Suppress("DEPRECATION") // monthNumber 无替代 API，kotlinx-datetime 尚未提供新接口
     fun getMonthDays(year: Int, month: Int): List<CalendarDay> {
         composeTraceBeginSection("getMonthDays:$year-$month")
-        val firstOfMonth = LocalDate(year, month, 1)
+        val info = getMonthGridInfo(year, month)
-        val dayOfWeekOffset = firstOfMonth.dayOfWeek.ordinal
+        val result = (0 until info.totalDays).map { i ->
-        val startDate = firstOfMonth.minus(DatePeriod(days = dayOfWeekOffset))
+            val date = info.startDate.plus(DatePeriod(days = i))
-        val nextMonth =
-            if (month == 12) LocalDate(year + 1, 1, 1) else LocalDate(year, month + 1, 1)
-        val daysInMonth = nextMonth.minus(DatePeriod(days = 1)).day
-        val rows = ((dayOfWeekOffset + daysInMonth - 1) / 7) + 1
-        val totalDays = rows * 7
-
-        val result = (0 until totalDays).map { i ->
-            val date = startDate.plus(DatePeriod(days = i))
             CalendarDay(
                 date = date,
                 isCurrentMonth = date.month.number == month && date.year == year,

core/src/main/kotlin/plus/rua/project/LunarCache.kt

@@ -1,31 +1,36 @@
 package plus.rua.project
 
 import com.tyme.solar.SolarDay
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import kotlinx.datetime.LocalDate
 
 /**
  * 农历/节气/节假日信息缓存。
  *
- * 使用 LinkedHashMap（accessOrder=true）实现 LRU 语义，读写速度优于 ConcurrentHashMap。
+ * 使用 LinkedHashMap（accessOrder=true）实现 LRU 语义。
- * 通过 @Synchronized 保护并发访问；冷启动时主线程单线程访问，偏向锁使其几乎零开销。
+ * 通过 [Mutex] 保护并发访问，协程友好，不阻塞线程。
+ *
+ * @param maxSize 缓存最大容量，默认 800
  */
-object LunarCache {
+class LunarCache(
-    private const val MAX_SIZE = 800
+    private val maxSize: Int = MAX_SIZE
+) {
+    private val mutex = Mutex()
 
     @Suppress("DEPRECATION")
     private val cache = LinkedHashMap<LocalDate, DayCellInfo>(256, 0.75f, true)
 
     /**
-     * 获取指定日期的信息，缓存 miss 时同步计算。
+     * 获取指定日期的信息，缓存 miss 时计算。
      */
-    @Synchronized
     @Suppress("DEPRECATION") // monthNumber 无替代 API
-    fun getOrCompute(date: LocalDate): DayCellInfo {
+    suspend fun getOrCompute(date: LocalDate): DayCellInfo = mutex.withLock {
-        cache[date]?.let { return it }
+        cache[date]?.let { return@withLock it }
         val computed = compute(date)
         cache[date] = computed
         trimIfNeeded()
-        return computed
+        computed
     }
 
     /**
@@ -33,8 +38,7 @@ object LunarCache {
      *
      * @param dates 日期列表
      */
-    @Synchronized
+    suspend fun precompute(dates: List<LocalDate>) = mutex.withLock {
-    fun precompute(dates: List<LocalDate>) {
         dates.forEach { date ->
             if (!cache.containsKey(date)) {
                 cache[date] = compute(date)
@@ -48,23 +52,21 @@ object LunarCache {
      *
      * 复用缓存中的 lunarMonthName 和 annotationText，避免重复创建 SolarDay。
      */
-    @Synchronized
     @Suppress("DEPRECATION") // monthNumber 无替代 API
-    fun formatLunarDate(date: LocalDate): String {
+    suspend fun formatLunarDate(date: LocalDate): String {
         val info = getOrCompute(date)
         val dayText = info.annotationText.removeSuffix("月")
         return "农历${info.lunarMonthName}${dayText}"
     }
 
     private fun trimIfNeeded() {
-        if (cache.size > MAX_SIZE) {
+        while (cache.size > maxSize) {
-            val toRemove = (cache.size * 0.2).toInt().coerceAtLeast(1)
             val iterator = cache.keys.iterator()
-            var removed = 0
+            if (iterator.hasNext()) {
-            while (iterator.hasNext() && removed < toRemove) {
                 iterator.next()
                 iterator.remove()
-                removed++
+            } else {
+                break
             }
         }
     }
@@ -104,6 +106,11 @@ object LunarCache {
         }
         return DayCellInfo(text, false, holidayBadge, lunarMonthName)
     }
+
+    companion object {
+        private const val MAX_SIZE = 800
+        val default = LunarCache()
+    }
 }
 
 /**

core/src/main/kotlin/plus/rua/project/ui/BottomCard.kt

@@ -17,7 +17,9 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.produceState
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -60,7 +62,12 @@ fun BottomCard(
 
     @Suppress("DEPRECATION") // monthNumber 无替代 API，kotlinx-datetime 尚未提供新接口
     val solarDesc = "${selectedDate.monthNumber}月${selectedDate.day}日"
-    val lunarDesc = remember(selectedDate) { LunarCache.formatLunarDate(selectedDate) }
+    val lunarDesc by produceState(
+        initialValue = "",
+        key1 = selectedDate
+    ) {
+        value = LunarCache.default.formatLunarDate(selectedDate)
+    }
     val shiftMessage = when (viewModel.shiftKindAt(selectedDate)) {
         ShiftKind.WORK -> "小小上班，轻松拿下！"
         ShiftKind.OFF -> "耶耶耶，美美休息！"

core/src/main/kotlin/plus/rua/project/ui/CalendarUtils.kt

@@ -38,6 +38,38 @@ const val CARD_GAP_COLLAPSED_DP = 12
 /** 线性插值 */
 fun lerp(start: Float, end: Float, fraction: Float): Float = start + (end - start) * fraction
 
+/**
+ * 月份网格信息，包含计算日历网格所需的所有数据。
+ */
+data class MonthGridInfo(
+    val year: Int,
+    val month: Int,
+    val firstOfMonth: LocalDate,
+    val offset: Int,
+    val startDate: LocalDate,
+    val daysInMonth: Int,
+    val rows: Int,
+    val totalDays: Int
+)
+
+/**
+ * 计算指定年月的日历网格信息。
+ *
+ * @param year 年份
+ * @param month 月份（1-12）
+ * @return 月份网格信息
+ */
+fun getMonthGridInfo(year: Int, month: Int): MonthGridInfo {
+    val firstOfMonth = LocalDate(year, month, 1)
+    val offset = firstOfMonth.dayOfWeek.ordinal
+    val startDate = firstOfMonth.minus(DatePeriod(days = offset))
+    val nextMonth = if (month == 12) LocalDate(year + 1, 1, 1) else LocalDate(year, month + 1, 1)
+    val daysInMonth = nextMonth.minus(DatePeriod(days = 1)).day
+    val rows = ((offset + daysInMonth - 1) / 7) + 1
+    val totalDays = rows * 7
+    return MonthGridInfo(year, month, firstOfMonth, offset, startDate, daysInMonth, rows, totalDays)
+}
+
 /**
  * 计算月份在日历网格中需要的行数（4/5/6）。
  *
@@ -46,11 +78,7 @@ fun lerp(start: Float, end: Float, fraction: Float): Float = start + (end - star
  * @return 网格行数
  */
 fun calculateWeeksCount(year: Int, month: Int): Int {
-    val firstOfMonth = LocalDate(year, month, 1)
+    return getMonthGridInfo(year, month).rows
-    val offset = firstOfMonth.dayOfWeek.ordinal
-    val nextMonth = if (month == 12) LocalDate(year + 1, 1, 1) else LocalDate(year, month + 1, 1)
-    val daysInMonth = nextMonth.minus(DatePeriod(days = 1)).day
-    return ((offset + daysInMonth - 1) / 7) + 1
 }
 
 /**

core/src/main/kotlin/plus/rua/project/ui/DayCell.kt

@@ -18,6 +18,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.produceState
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -36,6 +37,7 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.compose.ui.zIndex
 import kotlinx.datetime.LocalDate
+import plus.rua.project.DayCellInfo
 import plus.rua.project.LunarCache
 import plus.rua.project.ShiftKind
 
@@ -66,11 +68,19 @@ fun DayCell(
     shiftKind: ShiftKind?,
     showLegalHoliday: Boolean,
     onClick: () -> Unit,
-    modifier: Modifier = Modifier
+    modifier: Modifier = Modifier,
+    lunarCache: LunarCache = LunarCache.default
 ) {
-    val (annotationText, isAnnotationHighlight, holidayBadge) = remember(date) {
+    val lunarData by produceState(
-        LunarCache.getOrCompute(date)
+        initialValue = DayCellInfo("", false, null),
+        key1 = date,
+        key2 = lunarCache
+    ) {
+        value = lunarCache.getOrCompute(date)
     }
+    val annotationText = lunarData.annotationText
+    val isAnnotationHighlight = lunarData.isAnnotationHighlight
+    val holidayBadge = lunarData.holidayBadge
     val currentState = when {
         isSelected && isToday -> DayCellState.SELECTED_TODAY
         isSelected -> DayCellState.SELECTED