fix: streaming parsing to prevent crashes on low-end phones

app/build.gradle.kts

@@ -53,6 +53,7 @@ android {
     }
     testOptions {
         unitTests.isReturnDefaultValues = true
+        unitTests.all { it.maxHeapSize = "16m" }
     }
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_11

app/src/main/java/agzam/vyatsu/AppRoot.kt

@@ -23,7 +23,6 @@ fun AppRoot() {
     val container = app.container
 
     val scheduleViewModel: ScheduleViewModel = viewModel(factory = scheduleFactory(container))
-    val groupPickerViewModel: GroupPickerViewModel = viewModel(factory = groupPickerFactory(container))
     val updateViewModel: UpdateViewModel = viewModel(factory = updateFactory(container))
 
     val state by scheduleViewModel.uiState.collectAsState()
@@ -53,6 +52,7 @@ fun AppRoot() {
     }
 
     if (state.noGroup) {
+        val groupPickerViewModel: GroupPickerViewModel = viewModel(factory = groupPickerFactory(container))
         GroupPickerScreen(
             viewModel = groupPickerViewModel,
             onGroupPicked = { group -> scheduleViewModel.selectGroup(group.id) }

app/src/main/java/agzam/vyatsu/data/remote/GroupsParser.kt

@@ -3,8 +3,7 @@ package agzam.vyatsu.data.remote
 import agzam.vyatsu.domain.model.DateRange
 import agzam.vyatsu.domain.model.Group
 import agzam.vyatsu.domain.model.Season
-import android.util.Log
-import org.jsoup.Jsoup
+import java.io.InputStream
 
 /**
  * Основано на https://github.com/alirzaev/vyatsu-schedule-backend/blob/master/utils/extractors.py
@@ -14,6 +13,13 @@ object GroupsParser {
 
     private val groupPattern = Regex("""/reports/schedule/Group/(\d{4,})_([12])_(\d{8})_(\d{8})\.pdf""")
 
+    private val grpIdPattern = Regex("""data-grp_period_id="(\d+)"""")
+    private val parenthesized = Regex("""\(.*?\)\s?""")
+
+    private const val CHUNK_SIZE = 8192
+    private const val MAX_SLICE = 1 shl 16      // 64 KiB — защита от аномально длинных единиц
+    private const val MAX_PENDING = 1 shl 20    // 1 MiB — жёсткий потолок буфера
+
     private val shorthands = mapOf(
         "Институт биологии и биотехнологии (факультет)(ОРУ)" to "ИББТ",
         "Институт химии и экологии (факультет) (ОРУ)" to "ИнХимЭк",
@@ -33,41 +39,118 @@ object GroupsParser {
     )
 
     /**
-     * Извлекает список групп с HTML страницы
+     * Стриминговый парсер страницы групп: читает тело ответа по чанкам и
+     * разбирает его на лету, не материализуя весь HTML в память.
+     *
+     * Страница весит ~2.6MB, а на устройствах с маленькой кучей даже
+     * одиночный String такого размера — критично (jsoup-DOM и подавно приводил к OOM).
+     * За один проход извлекаем и список групп, и диапазоны дат из PDF-ссылок.
      */
-    fun parseGroups(html: String): List<Group> {
-        val doc = Jsoup.parse(html)
-        val container = doc.selectFirst("div.column-center_rasp") ?: return emptyList()
-        val tables = container.select("table[style~=border: none !important]")
+    fun parseStream(input: InputStream): ParsedGroups {
+        val reader = input.bufferedReader(Charsets.UTF_8)
+        val buf = CharArray(CHUNK_SIZE)
+        val pending = StringBuilder(CHUNK_SIZE * 2)
+        val groups = ArrayList<Group>()
+        val ranges = HashMap<String, HashMap<Season, MutableList<DateRange>>>()
+        var faculty = ""
 
-        return tables.flatMap { table ->
-            table.select("> tbody > tr, > tr").flatMap { row ->
-                Log.v("ROW", row.html());
-                val faculty = shortname(row.selectFirst("div.fak_name")?.text().orEmpty()) //
+        fun addRanges(text: String) {
+            for (m in groupPattern.findAll(text)) {
+                val groupId = m.groupValues[1]
+                val season = if (m.groupValues[2] == "1") Season.AUTUMN else Season.SPRING
+                val range = DateRange(m.groupValues[3], m.groupValues[4])
+                ranges.getOrPut(groupId) {
+                    hashMapOf(Season.AUTUMN to ArrayList(), Season.SPRING to ArrayList())
+                }.getOrPut(season) { ArrayList() }.add(range)
+            }
+        }
 
-                row.select("div.grpPeriod").map { grp ->
-                    Group(
-                        id = grp.attr("data-grp_period_id").dropLast(1),
-                        name = removeParenthesized(grp.text()),
+        while (true) {
+            val n = reader.read(buf)
+            if (n < 0) break
+            pending.append(buf, 0, n)
+
+            var pos = 0
+            while (pos < pending.length) {
+                val divAt = pending.indexOf("<div", pos)
+                val aAt = pending.indexOf("<a", pos)
+                val tagStart = when {
+                    divAt < 0 -> aAt
+                    aAt < 0 -> divAt
+                    else -> minOf(divAt, aAt)
+                }
+                if (tagStart < 0) {
+                    // хвостовой текст без div-тегов — обычный текст страницы
+                    pos = pending.length
+                    break
+                }
+                if (tagStart > pos) {
+                    addRanges(pending.substring(pos, tagStart))
+                }
+                val tagEnd = findTagEnd(pending, tagStart)
+                if (tagEnd < 0) break // тег не дочитан — ждём следующий чанк
+                val tagText = pending.substring(tagStart, tagEnd + 1)
+
+                val isDiv = tagText.startsWith("<div")
+                val isFakName = isDiv && tagText.contains("class=\"fak_name\"")
+                val isGrpPeriod = isDiv && tagText.contains("class=\"grpPeriod\"")
+                if (isFakName || isGrpPeriod) {
+                    val closeDiv = pending.indexOf("</div>", tagEnd + 1)
+                    if (closeDiv < 0) break // содержимое не дочитано — ждём следующий чанк
+                    addRanges(tagText)
+                    val content = pending.substring(tagEnd + 1, closeDiv)
+                    if (isFakName) {
+                        val name = content.trim()
+                        if (name.isNotEmpty()) faculty = shortname(name)
+                    } else {
+                        val m = grpIdPattern.find(tagText)
+                        if (m != null) {
+                            groups += Group(
+                                id = m.groupValues[1].dropLast(1),
+                                name = removeParenthesized(content),
                                 faculty = faculty
                             )
                         }
                     }
-        }
+                    pos = closeDiv + 6
+                } else {
+                    addRanges(tagText)
+                    pos = tagEnd + 1
                 }
 
-    fun parseDateRanges(html: String): Map<String, Map<Season, List<DateRange>>> {
-        val result = HashMap<String, HashMap<Season, MutableList<DateRange>>>()
-        groupPattern.findAll(html).forEach { m ->
-            val groupId = m.groupValues[1]
-            val season = if (m.groupValues[2] == "1") Season.AUTUMN else Season.SPRING
-            val range = DateRange(m.groupValues[3], m.groupValues[4])
-            result
-                .getOrPut(groupId) { hashMapOf(Season.AUTUMN to mutableListOf(), Season.SPRING to mutableListOf()) }
-                .getOrPut(season) { mutableListOf() }
-                .add(range)
+                if (pos > MAX_SLICE) {
+                    pending.delete(0, pos)
+                    pos = 0
                 }
-        return result
+            }
+            if (pos > 0 && pos <= pending.length) {
+                pending.delete(0, pos)
+            }
+            if (pending.length > MAX_PENDING) {
+                // на странице нет настолько длинных конструкций; страховка от аномалий
+                pending.delete(0, pending.length - MAX_SLICE)
+            }
+        }
+        return ParsedGroups(groups, ranges)
+    }
+
+    /** Ищет конец HTML-тега — символ '>' вне кавычек. */
+    private fun findTagEnd(s: CharSequence, start: Int): Int {
+        var i = start
+        var quote = 0.toChar()
+        while (i < s.length) {
+            val c = s[i]
+            if (quote != 0.toChar()) {
+                if (c == quote) quote = 0.toChar()
+            } else {
+                when (c) {
+                    '"', '\'' -> quote = c
+                    '>' -> return i
+                }
+            }
+            i++
+        }
+        return -1
     }
 
     private fun shortname(name: String): String {
@@ -76,5 +159,10 @@ object GroupsParser {
         return if (sh != null) "$sh ($stripped)" else stripped
     }
 
-    private fun removeParenthesized(name: String): String = name.replace(Regex("""\(.*?\)\s?"""), "").trim()
+    private fun removeParenthesized(name: String): String = name.replace(parenthesized, "").trim()
 }
+
+data class ParsedGroups(
+    val groups: List<Group>,
+    val dateRanges: Map<String, Map<Season, List<DateRange>>>
+)

app/src/main/java/agzam/vyatsu/data/remote/VyatsuHttpClient.kt

@@ -5,6 +5,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import java.io.InputStream
 import java.util.concurrent.TimeUnit
 
 /**
@@ -35,4 +36,15 @@ object VyatsuHttpClient {
         }
     }
 
+    /**
+     * Открывает потоковое тело ответа. Вызывающий обязан закрыть
+     * возвращённый [InputStream], чтобы вернуть соединение в пул.
+     */
+    suspend fun openStream(url: String): InputStream = withContext(Dispatchers.IO) {
+        val resp = client.newCall(Request.Builder().url(url).build()).execute()
+        Log.d(TAG, "GET $url -> ${resp.code}")
+        check(resp.isSuccessful) { "HTTP ${resp.code} for $url" }
+        resp.body!!.byteStream()
+    }
+
 }

app/src/main/java/agzam/vyatsu/data/repository/GroupRepositoryImpl.kt

@@ -9,9 +9,11 @@ import agzam.vyatsu.domain.ScheduleDates
 import agzam.vyatsu.domain.model.Group
 import agzam.vyatsu.domain.model.Season
 import agzam.vyatsu.domain.repository.GroupRepository
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.withContext
 
 class GroupRepositoryImpl(
     private val groupDao: GroupDao,
@@ -40,11 +42,11 @@ class GroupRepositoryImpl(
     }
 
     private suspend fun refresh() {
-        val html = VyatsuHttpClient.getText(VyatsuUrls.GROUPS_PAGE)
-        val groups = GroupsParser.parseGroups(html)
-        val ranges = GroupsParser.parseDateRanges(html)
-        val entities = groups.map { group ->
-            val range = ranges[group.id]
+        val parsed = withContext(Dispatchers.IO) {
+            VyatsuHttpClient.openStream(VyatsuUrls.GROUPS_PAGE).use(GroupsParser::parseStream)
+        }
+        val entities = parsed.groups.map { group ->
+            val range = parsed.dateRanges[group.id]
             val autumn = range?.get(Season.AUTUMN)?.lastOrNull()
             val spring = range?.get(Season.SPRING)?.lastOrNull()
             GroupEntity(

app/src/main/java/agzam/vyatsu/ui/schedule/ScheduleScreen.kt

@@ -18,6 +18,7 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.only
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.statusBars
 import androidx.compose.foundation.layout.systemBars
 import androidx.compose.foundation.layout.width
@@ -41,6 +42,7 @@ import androidx.compose.material3.FilterChipDefaults
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
+import androidx.compose.material3.LocalContentColor
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
@@ -54,6 +56,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.compositeOver
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import java.time.DayOfWeek
@@ -73,6 +76,12 @@ fun ScheduleScreen(viewModel: ScheduleViewModel, onSwitchGroup: () -> Unit) {
         TopAppBar(
             title = { Text(state.groupName ?: "Расписание", style = MaterialTheme.typography.titleMedium) },
             actions = {
+                if (state.isLoading && state.schedule != null) {
+                    CircularProgressIndicator(
+                        modifier = Modifier.size(24.dp),
+                        strokeWidth = 2.dp
+                    )
+                }
                 TextButton(onClick = { onSwitchGroup() }) {
                     Text("Сменить группу")
                 }
@@ -84,16 +93,7 @@ fun ScheduleScreen(viewModel: ScheduleViewModel, onSwitchGroup: () -> Unit) {
         )
         Column(Modifier.fillMaxSize().padding(horizontal = 0.dp, vertical = 0.dp)) {
             when {
-                state.isSyncing && state.schedule == null -> {
-                    Row(
-                        Modifier.fillMaxWidth(),
-                        horizontalArrangement = Arrangement.Center
-                    ) {
-                        CircularProgressIndicator()
-                    }
-                }
-
-                state.schedule == null -> {
+                state.schedule == null && state.loadError -> {
                     Column(
                         Modifier.fillMaxWidth(),
                         horizontalAlignment = Alignment.CenterHorizontally
@@ -108,6 +108,15 @@ fun ScheduleScreen(viewModel: ScheduleViewModel, onSwitchGroup: () -> Unit) {
                     }
                 }
 
+                state.schedule == null -> {
+                    Row(
+                        Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.Center
+                    ) {
+                        CircularProgressIndicator()
+                    }
+                }
+
                 else -> {
                     val schedule = state.schedule!!
                     val weekDays = state.weekStart
@@ -148,7 +157,6 @@ fun ScheduleScreen(viewModel: ScheduleViewModel, onSwitchGroup: () -> Unit) {
                         )
 
                         HorizontalDivider(Modifier.padding(top=0.dp, start = hPadding, end = hPadding))
-
                         if (day.intervals.all { it.lessons.isEmpty() }) {
                             Text("Занятий нет", style = MaterialTheme.typography.bodyLarge)
                         } else {
@@ -309,10 +317,11 @@ private fun LessonSlot(slotIndex: Int, slot: TimeSlot) {
             Text("—", style = MaterialTheme.typography.bodyMedium)
         } else {
             slot.lessons.forEachIndexed { index, lesson ->
-                val backgroundColor = if (indexColor % 2 == 0) {
-                    MaterialTheme.colorScheme.surfaceBright
-                } else {
-                    MaterialTheme.colorScheme.surfaceVariant
+                var baseSurface = Modifier.fillMaxWidth().padding(vertical = 2.dp)
+                if ((indexColor) % 2 != 0) {
+                    baseSurface = baseSurface.background(
+                        MaterialTheme.colorScheme.surfaceContainer
+                    );
                 }
                 indexColor++
                 // XXX:
@@ -322,7 +331,7 @@ private fun LessonSlot(slotIndex: Int, slot: TimeSlot) {
                 // Меню на onLongClick?
                 SelectionContainer() {
                     Column(
-                        Modifier.fillMaxWidth().padding(vertical = 2.dp).background(backgroundColor)
+                        baseSurface
                         // XXX: combinedClickable?
                         //.combinedClickable(
                         //    onClick = {

app/src/main/java/agzam/vyatsu/ui/schedule/ScheduleViewModel.kt

@@ -37,6 +37,7 @@ class ScheduleViewModel(
 
     fun selectGroup(groupId: String) {
         currentGroupId = groupId
+        _uiState.value = _uiState.value.copy(noGroup = false, isLoading = true, loadError = false)
         viewModelScope.launch {
             preferencesRepository.setSelectedGroup(groupId)
             val groupName = groupRepository.getGroups().firstOrNull { it.id == groupId }?.name
@@ -61,7 +62,7 @@ class ScheduleViewModel(
             }
 
             launch {
-                syncIfMissingToday(groupId)
+                syncIfMissing(groupId)
             }
         }
     }
@@ -96,7 +97,9 @@ class ScheduleViewModel(
             schedule = schedule,
             weekStart = weekStart,
             dayDate = dayDate,
-            todayDate = todayDate
+            todayDate = todayDate,
+            isLoading = false,
+            loadError = false
         )
     }
 
@@ -128,30 +131,36 @@ class ScheduleViewModel(
         }
     }
 
-    private suspend fun syncIfMissingToday(groupId: String) {
-        val schedule = scheduleRepository.getSchedule(groupId)
-        val today = ScheduleDates.moscowToday()
-        val hasTodayPeriod = schedule?.periodOf(today) != null
-        if (hasTodayPeriod) return
-        _uiState.value = _uiState.value.copy(isSyncing = true)
-        scheduleRepository.sync(groupId)
-        _uiState.value = _uiState.value.copy(isSyncing = false)
+    private suspend fun syncIfMissing(groupId: String) {
+        if (scheduleRepository.getSchedule(groupId) != null) {
+            _uiState.value = _uiState.value.copy(isLoading = false)
+            return
+        }
+        loadSchedule(groupId)
+    }
+
+    private suspend fun loadSchedule(groupId: String) {
+        _uiState.value = _uiState.value.copy(isLoading = true, loadError = false)
+        val schedule = scheduleRepository.sync(groupId)
+        _uiState.value = if (schedule != null) {
+            _uiState.value.copy(isLoading = false, loadError = false)
+        } else {
+            _uiState.value.copy(isLoading = false, loadError = true)
+        }
     }
 
     fun switchGroup() {
         viewModelScope.launch {
             currentGroupId = null
             preferencesRepository.clearSelectedGroup()
-            _uiState.value = _uiState.value.copy(noGroup = true)
+            _uiState.value = _uiState.value.copy(noGroup = true, isLoading = false, loadError = false)
         }
     }
 
     fun refresh() {
         val groupId = currentGroupId ?: return
         viewModelScope.launch {
-            _uiState.value = _uiState.value.copy(isRefreshing = true)
-            scheduleRepository.sync(groupId)
-            _uiState.value = _uiState.value.copy(isRefreshing = false)
+            loadSchedule(groupId)
         }
     }
 
@@ -175,8 +184,8 @@ class ScheduleViewModel(
 
 data class ScheduleUiState(
     val noGroup: Boolean = false,
-    val isRefreshing: Boolean = false,
-    val isSyncing: Boolean = false,
+    val isLoading: Boolean = false,
+    val loadError: Boolean = false,
     val schedule: Schedule? = null,
     val groupName: String? = null,
     val weekStart: LocalDate? = null,