fix: 修复实例日志窗口停更与日志行重叠

日志停更（实例启动后日志不再刷新）：
- process.rs 的 XML 日志分支原先使用 quick-xml 流式异步 Reader。
  该解析器在任何 I/O/解析错误或瞬时 Eof 后会把内部状态永久置为
  ParseState::Done（quick-xml #513），此后永远只返回 Eof，导致
  日志转发在客户端启动、日志量变大后彻底停止。
- 改为把原始字节累积到缓冲区，切出完整的 <log4j:Event …>…
  </log4j:Event> 帧后逐帧同步解析；坏帧/分片帧只跳过，不再毒化
  解析状态，日志转发持续进行。
- 新增 take_next_log4j_frame（切帧）与 handle_log4j_frame（单帧
  解析与转发）两个辅助函数。

日志行重叠：
- LogViewport.vue 原先用手动虚拟滚动，按估算高度为每行设置固定
  height；估算与实际渲染高度不符（高亮、wrap 折行等）时，绝对
  定位的行会溢出并相互重叠。
- 改用原生虚拟化 content-visibility: auto + contain-intrinsic-size，
  全量渲染由浏览器跳过屏外行的布局绘制，进入视口时以真实高度
  修正，从根本上消除估算误差导致的重叠。
- 保留 scrollToBottom / 自动跟随底部 / 搜索高亮 / 错误警告配色
  等既有行为与对外接口。

packages/app-lib/src/state/process.rs

@@ -616,220 +616,62 @@ impl Process {
         let mut buf_reader = BufReader::new(reader);
 
         if xml_logging {
-            let mut reader = Reader::from_reader(buf_reader);
+            // NOTE: we deliberately do NOT use quick-xml's streaming async reader
-            reader.config_mut().enable_all_checks(false);
+            // here. Its parser marks itself `ParseState::Done` permanently after
-
+            // any I/O/parse error or a transient `Eof` (see quick-xml #513), so a
-            let mut buf = Vec::new();
+            // single split XML frame on the live pipe would silently kill all
-            let mut current_event = Log4jEvent::default();
+            // further log forwarding — which is exactly the "logs stop after the
-            let mut in_event = false;
+            // client finished starting" bug.
-            let mut in_message = false;
+            //
-            let mut in_throwable = false;
+            // Instead we accumulate raw bytes into a buffer and cut out complete
-            let mut current_content = String::new();
+            // `<log4j:Event ...>…</log4j:Event>` frames, parsing each frame in one
+            // synchronous pass. Malformed or partial frames are skipped without
+            // poisoning the stream, so forwarding always continues.
+            let mut pending = String::new();
+            let mut chunk = [0u8; 8192];
 
             loop {
-                match reader.read_event_into_async(&mut buf).await {
+                let read = match tokio::io::AsyncReadExt::read(&mut buf_reader, &mut chunk).await {
+                    Ok(0) => break,
+                    Ok(n) => n,
                     Err(e) => {
-                        tracing::error!(
+                        tracing::warn!("Live log read error: {e}");
-                            "Error at position {}: {:?}",
-                            reader.buffer_position(),
-                            e
-                        );
                         break;
                     }
-                    // exits the loop when reaching end of file
-                    Ok(Event::Eof) => break,
-
-                    Ok(Event::Start(e)) => {
-                        match e.name().as_ref() {
-                            b"log4j:Event" => {
-                                // Reset for new event
-                                current_event = Log4jEvent::default();
-                                in_event = true;
-
-                                // Extract attributes
-                                for attr in e.attributes().flatten() {
-                                    let key = String::from_utf8_lossy(
-                                        attr.key.into_inner(),
-                                    )
-                                    .to_string();
-                                    let value =
-                                        String::from_utf8_lossy(&attr.value)
-                                            .to_string();
-
-                                    match key.as_str() {
-                                        "logger" => {
-                                            current_event.logger_name =
-                                                Some(value)
-                                        }
-                                        "level" => {
-                                            current_event.level = Some(value)
-                                        }
-                                        "thread" => {
-                                            current_event.thread_name =
-                                                Some(value)
-                                        }
-                                        "timestamp" => {
-                                            current_event.timestamp_millis =
-                                                value.parse::<i64>().ok()
-                                        }
-                                        _ => {}
-                                    }
-                                }
-                            }
-                            b"log4j:Message" => {
-                                in_message = true;
-                                current_content = String::new();
-                            }
-                            b"log4j:Throwable" => {
-                                in_throwable = true;
-                                current_content = String::new();
-                            }
-                            _ => {}
-                        }
-                    }
-                    Ok(Event::End(e)) => {
-                        match e.name().as_ref() {
-                            b"log4j:Message" => {
-                                in_message = false;
-                                current_event.message =
-                                    Some(current_content.clone());
-                            }
-                            b"log4j:Throwable" => {
-                                in_throwable = false;
-                                current_event.throwable =
-                                    if current_content.is_empty() {
-                                        None
-                                    } else {
-                                        Some(current_content.clone())
                 };
 
-                                // Write log entry + throwable to file
+                pending.push_str(&String::from_utf8_lossy(&chunk[..read]));
-                                if let Some(formatted_log) =
-                                    Self::format_log4j_entry(&current_event)
-                                {
-                                    if let Err(e) = Process::append_to_log_file(
-                                        &log_path,
-                                        &formatted_log,
-                                    ) {
-                                        tracing::error!(
-                                            "Failed to write to log file: {}",
-                                            e
-                                        );
-                                    }
 
-                                    if let Some(ref throwable) =
+                // Drain every complete frame currently buffered.
-                                        current_event.throwable
+                while let Some(frame) = take_next_log4j_frame(&mut pending) {
-                                        && let Err(e) =
+                    Self::handle_log4j_frame(
-                                            Process::append_to_log_file(
-                                                &log_path, throwable,
-                                            )
-                                    {
-                                        tracing::error!(
-                                            "Failed to write throwable to log file: {}",
-                                            e
-                                        );
-                                    }
-                                }
-
-                                Self::emit_log4j_event(
-                                    instance_id,
-                                    &current_event,
-                                );
-                            }
-                            b"log4j:Event" => {
-                                in_event = false;
-                                // If no throwable was present, write the log entry at the end of the event
-                                if current_event.message.is_some()
-                                    && current_event.throwable.is_none()
-                                {
-                                    if let Some(formatted_log) =
-                                        Self::format_log4j_entry(&current_event)
-                                        && let Err(e) =
-                                            Process::append_to_log_file(
-                                                &log_path,
-                                                &formatted_log,
-                                            )
-                                    {
-                                        tracing::error!(
-                                            "Failed to write to log file: {}",
-                                            e
-                                        );
-                                    }
-
-                                    if let Some(timestamp_millis) =
-                                        current_event.timestamp_millis
-                                    {
-                                        let timestamp =
-                                            timestamp_millis.to_string();
-                                        let message = current_event
-                                            .message
-                                            .as_deref()
-                                            .unwrap_or("")
-                                            .trim();
-                                        crate::api::multiplayer::observe_minecraft_log(
                         instance_id,
                         instance_name,
                         process_id,
-                                        message,
+                        &log_path,
+                        &frame,
                     )
                     .await;
-                                        if let Err(e) = Self::maybe_handle_server_join_logging(
+                }
-											instance_id,
+
-											&timestamp,
+                // Guard against a runaway buffer if no frame delimiters ever
-											message,
+                // appear (e.g. raw non-XML output on a logging-configured
-                                        ).await {
+                // instance). Flush it as legacy text so it is not lost.
-                                            tracing::error!("Failed to handle server join logging: {e}");
+                if pending.len() > MAX_PERSISTED_LOG_LINE_BYTES {
+                    let text = std::mem::take(&mut pending);
+                    if let Err(e) = Self::append_to_log_file(&log_path, &text) {
+                        tracing::warn!("Failed to write to log file: {e}");
+                    }
+                    Self::emit_legacy_log(instance_id, text.trim_end());
                 }
             }
 
-                                    Self::emit_log4j_event(
+            // Flush any trailing partial content on stream end.
-                                        instance_id,
+            if !pending.trim().is_empty() {
-                                        &current_event,
+                if let Err(e) = Self::append_to_log_file(&log_path, &pending) {
-                                    );
+                    tracing::warn!("Failed to write to log file: {e}");
                 }
-                            }
+                Self::emit_legacy_log(instance_id, pending.trim_end());
-                            _ => {}
-                        }
-                    }
-                    Ok(Event::Text(mut e)) => {
-                        if in_message || in_throwable {
-                            if let Ok(text) = e.xml_content() {
-                                append_bounded_log4j_content(
-                                    &mut current_content,
-                                    &text,
-                                );
-                            }
-                        } else if !in_event
-                            && !e.inplace_trim_end()
-                            && !e.inplace_trim_start()
-                            && let Ok(text) = e.xml_content()
-                        {
-                            if let Err(e) = Process::append_to_log_file(
-                                &log_path,
-                                &format!("{text}\n"),
-                            ) {
-                                tracing::error!(
-                                    "Failed to write to log file: {}",
-                                    e
-                                );
-                            }
-                            Self::emit_legacy_log(instance_id, &text);
-                        }
-                    }
-                    Ok(Event::CData(e)) => {
-                        if (in_message || in_throwable)
-                            && let Ok(text) = e.xml_content()
-                        {
-                            append_bounded_log4j_content(
-                                &mut current_content,
-                                &text,
-                            );
-                        }
-                    }
-                    _ => (),
-                }
-
-                buf.clear();
             }
         } else {
             while let Ok(Some(line)) =
@@ -862,6 +704,164 @@ impl Process {
         }
     }
 
+    /// Parses one complete `<log4j:Event …>…</log4j:Event>` frame and forwards
+    /// its content to the log file / frontend. A frame that fails to parse is
+    /// logged and dropped; it never stops the reader loop.
+    async fn handle_log4j_frame(
+        instance_id: &str,
+        instance_name: &str,
+        process_id: &str,
+        log_path: &Path,
+        frame: &str,
+    ) {
+        let mut reader = Reader::from_str(frame);
+        reader.config_mut().enable_all_checks(false);
+
+        let mut current_event = Log4jEvent::default();
+        let mut in_message = false;
+        let mut in_throwable = false;
+        let mut current_content = String::new();
+
+        let mut buf = Vec::new();
+        loop {
+            match reader.read_event_into(&mut buf) {
+                Err(e) => {
+                    tracing::warn!("Malformed live log frame: {e}");
+                    break;
+                }
+                Ok(Event::Eof) => break,
+                Ok(Event::Start(e)) => match e.name().as_ref() {
+                    b"log4j:Event" => {
+                        current_event = Log4jEvent::default();
+                        for attr in e.attributes().flatten() {
+                            let key =
+                                String::from_utf8_lossy(attr.key.into_inner())
+                                    .to_string();
+                            let value = String::from_utf8_lossy(&attr.value)
+                                .to_string();
+                            match key.as_str() {
+                                "logger" => {
+                                    current_event.logger_name = Some(value)
+                                }
+                                "level" => current_event.level = Some(value),
+                                "thread" => {
+                                    current_event.thread_name = Some(value)
+                                }
+                                "timestamp" => {
+                                    current_event.timestamp_millis =
+                                        value.parse::<i64>().ok()
+                                }
+                                _ => {}
+                            }
+                        }
+                    }
+                    b"log4j:Message" => {
+                        in_message = true;
+                        current_content = String::new();
+                    }
+                    b"log4j:Throwable" => {
+                        in_throwable = true;
+                        current_content = String::new();
+                    }
+                    _ => {}
+                },
+                Ok(Event::End(e)) => match e.name().as_ref() {
+                    b"log4j:Message" => {
+                        in_message = false;
+                        current_event.message = Some(current_content.clone());
+                    }
+                    b"log4j:Throwable" => {
+                        in_throwable = false;
+                        current_event.throwable =
+                            if current_content.is_empty() {
+                                None
+                            } else {
+                                Some(current_content.clone())
+                            };
+                    }
+                    b"log4j:Event" => {
+                        if let Some(formatted) =
+                            Self::format_log4j_entry(&current_event)
+                        {
+                            if let Err(e) =
+                                Self::append_to_log_file(log_path, &formatted)
+                            {
+                                tracing::error!(
+                                    "Failed to write to log file: {e}"
+                                );
+                            }
+                            if let Some(ref throwable) = current_event.throwable
+                                && let Err(e) = Self::append_to_log_file(
+                                    log_path,
+                                    throwable,
+                                )
+                            {
+                                tracing::error!(
+                                    "Failed to write throwable to log file: {e}"
+                                );
+                            }
+
+                            if let Some(timestamp_millis) =
+                                current_event.timestamp_millis
+                            {
+                                let timestamp = timestamp_millis.to_string();
+                                let message = current_event
+                                    .message
+                                    .as_deref()
+                                    .unwrap_or("")
+                                    .trim();
+                                crate::api::multiplayer::observe_minecraft_log(
+                                    instance_id,
+                                    instance_name,
+                                    process_id,
+                                    message,
+                                )
+                                .await;
+                                if let Err(e) =
+                                    Self::maybe_handle_server_join_logging(
+                                        instance_id,
+                                        &timestamp,
+                                        message,
+                                    )
+                                    .await
+                                {
+                                    tracing::error!(
+                                        "Failed to handle server join logging: {e}"
+                                    );
+                                }
+                            }
+
+                            Self::emit_log4j_event(instance_id, &current_event);
+                        }
+                    }
+                    _ => {}
+                },
+                Ok(Event::Text(e)) => {
+                    if (in_message || in_throwable)
+                        && let Ok(text) = e.xml_content()
+                    {
+                        append_bounded_log4j_content(
+                            &mut current_content,
+                            &text,
+                        );
+                    }
+                }
+                Ok(Event::CData(e)) => {
+                    if (in_message || in_throwable)
+                        && let Ok(text) = e.xml_content()
+                    {
+                        append_bounded_log4j_content(
+                            &mut current_content,
+                            &text,
+                        );
+                    }
+                }
+                _ => (),
+            }
+            buf.clear();
+        }
+    }
+
     fn format_timestamp(timestamp_millis: Option<i64>) -> String {
         if let Some(timestamp_val) = timestamp_millis {
             let datetime_utc = if timestamp_val > i32::MAX as i64 {
@@ -1267,7 +1267,28 @@ impl Process {
         Ok(())
     }
 }
+/// Cuts the next complete `<log4j:Event …>…</log4j:Event>` frame out of the
+/// live buffer and returns it as an owned string, leaving any trailing partial
+/// frame in place.
+///
+/// Returns `None` when the buffer does not yet contain a full frame. This is a
+/// plain string operation on purpose: it never poisons any parser state, so a
+/// split or malformed frame on the live pipe cannot stop log forwarding.
+fn take_next_log4j_frame(buffer: &mut String) -> Option<String> {
+    const OPEN: &str = "<log4j:Event";
+    const CLOSE: &str = "</log4j:Event>";
 
+    let start = buffer.find(OPEN)?;
+    // Discard anything before the frame (raw text, XML prolog, …).
+    if start > 0 {
+        buffer.drain(..start);
+    }
+    let close = buffer.find(CLOSE)?;
+    let end = close + CLOSE.len();
+    let frame = buffer[..end].to_string();
+    buffer.drain(..end);
+    Some(frame)
+}
 #[cfg(test)]
 mod post_upgrade_tests {
     use super::*;

packages/ui/src/layouts/shared/console/components/LogViewport.vue

@@ -19,22 +19,21 @@
 			/>
 		</div>
 
+		<!--
+			Native virtualization: every line is rendered, but `content-visibility:
+			auto` lets the browser skip layout/paint for off-screen lines, while
+			`contain-intrinsic-size` gives the skipped elements a placeholder size
+			so the scrollbar stays stable. This avoids the manual height estimation
+			that used to make tall (wrapped / highlighted) lines overlap.
+		-->
+		<div v-else class="log-viewport-spacer relative w-full min-w-max">
 			<div
-			v-else
+				v-for="item in lines"
-			class="log-viewport-spacer relative w-full min-w-max"
-			:style="{ height: totalHeight + 'px' }"
-		>
-			<div
-				class="absolute inset-x-0 top-0"
-				:style="{ transform: 'translateY(' + topOffset + 'px)' }"
-			>
-				<div
-					v-for="item in windowItems"
 				:key="item.originalIndex"
 				:data-line="item.originalIndex + 1"
-					class="log-line flex items-stretch whitespace-pre"
+				class="log-line log-line-cv flex items-stretch whitespace-pre"
 				:class="entryClass(item.line)"
-					:style="{ height: estimateHeight(item) + 'px' }"
+				:style="lineStyle"
 			>
 				<span
 					class="flex shrink-0 w-[52px] items-center justify-end leading-none text-right text-secondary bg-surface-3 border-r border-solid border-surface-3 select-none overflow-hidden"
@@ -46,7 +45,6 @@
 				></span>
 			</div>
 		</div>
-		</div>
 
 		<Transition name="scroll-to-bottom-fade">
 			<div v-if="lines.length > 0 && !stickToBottom" class="absolute bottom-4 right-4 z-10">
@@ -99,114 +97,21 @@ const props = withDefaults(
 )
 
 const viewportRef = ref<HTMLElement | null>(null)
-const scrollTop = ref(0)
-const viewportHeight = ref(0)
 const stickToBottom = ref(true)
 
-// 行高：单行 = 字号 × 1.4（与等宽字体匹配），wrap 时按估算折行数放大
+// Placeholder row height for `contain-intrinsic-size`. Native
-const lineHeightPx = computed(() => Math.round(props.fontSize * 1.4))
+// `content-visibility: auto` replaces this with the real measured height once a
-// wrap 折行估算：0.6em 为等宽字符平均宽，乘 0.9 留保守余量（行高宁高勿矮，避免内容溢出重叠）
+// line enters the viewport, so it only needs to be a reasonable estimate to
-const charsPerLine = computed(() => {
+// keep the scrollbar from jumping. Wrapped lines can be taller, so bias higher.
-	const vp = viewportRef.value
+const intrinsicLineHeight = computed(() => {
-	if (!vp) return 120
+	const single = Math.round(props.fontSize * 1.4)
-	return Math.max(20, Math.floor((vp.clientWidth / (props.fontSize * 0.6)) * 0.9))
+	return props.wrap ? single * 2 : single
 })
 
-function estimateHeight(item: ViewportLine): number {
+const lineStyle = computed(() => ({
-	if (!props.wrap) return lineHeightPx.value
+	'content-visibility': 'auto',
-	const lines = Math.max(1, Math.ceil(item.line.text.length / charsPerLine.value))
+	'contain-intrinsic-size': `auto ${intrinsicLineHeight.value}px`,
-	return lines * lineHeightPx.value
+}))
-}
-
-// 高度前缀和缓存：lines/wrap/fontSize 变化时重建（O(n)），滚动时二分查找（O(log n)）
-// 总高度必须是响应式的：普通变量 + 无依赖 computed 会缓存过期值，
-// 清空控制台后模板不再读取它，重启后 spacer 会以旧高度渲染（底部空白）。
-let heightPrefix: number[] | null = null
-const heightTotal = ref(0)
-
-function rebuildHeights() {
-	const n = props.lines.length
-	if (!props.wrap) {
-		heightPrefix = null
-		heightTotal.value = n * lineHeightPx.value
-		return
-	}
-	const prefix = new Array<number>(n)
-	let acc = 0
-	for (let i = 0; i < n; i++) {
-		prefix[i] = acc
-		acc += estimateHeight(props.lines[i]!)
-	}
-	heightPrefix = prefix
-	heightTotal.value = acc
-}
-
-watch(
-	() => [props.lines, props.wrap, props.fontSize] as const,
-	([lines], previous) => {
-		rebuildHeights()
-		// A fresh stream after an empty console (clear, restart, initial
-		// hydration) always resumes bottom-following.
-		if (previous && previous[0].length === 0 && lines.length > 0) {
-			stickToBottom.value = true
-		}
-		if (lines.length === 0) {
-			// Reset the virtual window state along with the DOM scroll position;
-			// browsers may clamp silently without firing a scroll event.
-			scrollTop.value = 0
-			if (viewportRef.value) viewportRef.value.scrollTop = 0
-		}
-		if (stickToBottom.value) {
-			nextTick(scrollToBottom)
-		}
-	},
-	{ immediate: true },
-)
-
-const totalHeight = computed(() => heightTotal.value)
-
-// 虚拟窗口：可见行 + 上下缓冲
-const WINDOW_BUFFER = 15
-
-function computeWindow(): { items: ViewportLine[]; startIndex: number } {
-	const n = props.lines.length
-	if (n === 0) return { items: [], startIndex: 0 }
-
-	let start = 0
-	let end = n - 1
-
-	if (n > WINDOW_BUFFER * 2) {
-		if (props.wrap && heightPrefix) {
-			let lo = 0
-			let hi = n - 1
-			while (lo < hi) {
-				const mid = (lo + hi + 1) >> 1
-				if (heightPrefix[mid]! <= scrollTop.value) lo = mid
-				else hi = mid - 1
-			}
-			start = Math.max(0, lo - WINDOW_BUFFER)
-		} else {
-			const first = Math.floor(scrollTop.value / lineHeightPx.value)
-			start = Math.max(0, first - WINDOW_BUFFER)
-		}
-		end = Math.min(
-			n - 1,
-			start + Math.ceil(viewportHeight.value / lineHeightPx.value) + WINDOW_BUFFER * 2,
-		)
-	}
-
-	return { items: props.lines.slice(start, end + 1), startIndex: start }
-}
-
-const windowState = computed(computeWindow)
-const windowItems = computed(() => windowState.value.items)
-
-const topOffset = computed(() => {
-	const { startIndex } = windowState.value
-	if (startIndex === 0) return 0
-	if (props.wrap && heightPrefix) return heightPrefix[startIndex]!
-	return startIndex * lineHeightPx.value
-})
 
 function entryClass(line: LogLine): string {
 	if (line.level === 'error') return 'entry-error'
@@ -235,43 +140,47 @@ function renderLine(item: ViewportLine): string {
 function handleScroll() {
 	const vp = viewportRef.value
 	if (!vp) return
-	scrollTop.value = vp.scrollTop
+	stickToBottom.value = vp.scrollTop + vp.clientHeight >= vp.scrollHeight - 32
-	viewportHeight.value = vp.clientHeight
-	stickToBottom.value = vp.scrollTop + vp.clientHeight >= vp.scrollHeight - lineHeightPx.value * 2
 }
 
 function scrollToBottom() {
 	const vp = viewportRef.value
 	if (!vp) return
 	vp.scrollTop = vp.scrollHeight
-	scrollTop.value = vp.scrollTop
 	stickToBottom.value = true
 }
 
-function syncViewportSize() {
-	const vp = viewportRef.value
-	if (!vp) return
-	viewportHeight.value = vp.clientHeight
-	// 窗口宽度影响 wrap 折行估算，resize 时重建高度缓存
-	if (props.wrap) rebuildHeights()
-}
-
 let resizeObserver: ResizeObserver | null = null
 
 onMounted(() => {
-	syncViewportSize()
 	if (stickToBottom.value) nextTick(scrollToBottom)
-	resizeObserver = new ResizeObserver(syncViewportSize)
+	resizeObserver = new ResizeObserver(() => {
+		if (stickToBottom.value) scrollToBottom()
+	})
 	if (viewportRef.value) resizeObserver.observe(viewportRef.value)
-	window.addEventListener('resize', syncViewportSize)
 })
 
 onBeforeUnmount(() => {
 	resizeObserver?.disconnect()
 	resizeObserver = null
-	window.removeEventListener('resize', syncViewportSize)
 })
 
+// Follow the tail while new lines stream in, but only when the user has not
+// scrolled up. A fresh stream after an empty console (clear, restart, initial
+// hydration) always resumes bottom-following.
+watch(
+	() => props.lines,
+	(lines, previous) => {
+		if (previous && previous.length === 0 && lines.length > 0) {
+			stickToBottom.value = true
+		}
+		if (stickToBottom.value) {
+			nextTick(scrollToBottom)
+		}
+	},
+	{ immediate: true },
+)
+
 defineExpose({
 	scrollToBottom,
 })