ncm 三期三批: 歌曲对象瘦身(1324→608B)+滑动窗口(NCM_SONG_WINDOW=256, 取消1000截断支撑任意长度歌单)+播放快照解耦 — agent-251

- core/ncm_api.h: ncm_song_t 瘦身 id24/name128/art96/al96/pic256/dt int32 (1324B→608B)
- appstate.c 滑动窗口: song_ids 全量 trackIds 索引(16384) + songs[256] 窗口感知
  (song_valid 位图/window_base/滑窗 memmove 保留重叠), ensure_range 批网格(100)对齐
  预取, songmeta.c 盘缓存 <cache_dir>/meta/<id>.bin (回滚/二次进入 0 网络请求)
- playlist.c 触底分页退役→视口 ensure(±24 行), 占位行可直点(播放线程 fetch 物化),
  footer 改视口区间/总数
- 播放兼容: g_play.play_song 快照(mu), run_song 起播物化后全链路(下载/歌词/IPC META/
  播放页 UI)读快照——窗口滑出当前播放曲不崩; 边界 song_count→track_ids_count
- 验证(0 真实请求): pagination_sim 全 PASS(5191 无截断/52 批); window_sim 6000 首
  全程下滚 750 步视口全物化/song_detail 恰 60 次/回滚+0 请求/播放 fetch 不滑窗;
  core 宿主+qemu 全 PASS; mipsel -Wall -Wextra 0 warning, bss 2052068→1080900(-47%)
- 未部署真机(设备音频线排查中, 部署留主会话)

patch_v2/ncm_app/app/ui/player.c

@@ -25,6 +25,7 @@ static ncm_rect_t   r_cont;
 static int          g_custom_disc, g_custom_dyn;
 static int          g_landscape;
 static int          g_last_pos_ms, g_last_state, g_last_line, g_last_song;
+static char         g_last_meta_id[24];   /* 已上封面的元数据 id（快照滞后 settle 时纠正封面/歌名） */
 
 /* 运行期几何（player_compute_geom 填充；各带绘制物/命中共用）。 */
 static ncm_rect_t g_disc_r, g_dyn_r;             /* 盘带 / 动态带 bbox（不重叠） */
@@ -40,7 +41,16 @@ static ncm_rect_t g_lyr;                         /* 歌词区 */
 static int cur_song(void)
 {
     int c = player_manager_playing_song();
-    return (c >= 0 && c < g_st.song_count) ? c : -1;
+    return (c >= 0 && c < g_st.track_ids_count) ? c : -1;
+}
+
+/* 当前播放曲元数据（§17）：优先播放快照（窗口无关）；快照未就绪时退窗口拷贝。 */
+static int cur_song_meta(ncm_song_t *out)
+{
+    if (player_manager_current_song(out) == 0) return 0;
+    int sc = cur_song();
+    if (sc >= 0 && appstate_song_copy(sc, out) == 0) return 0;
+    return -1;
 }
 
 static void fmt_ms(int64_t ms, char *out, size_t sz)
@@ -188,10 +198,10 @@ static void plr_draw_dyn(void *ctx)
     if (meow_ui_activity_active() != ACT_PLAYER) return;
     const meow_theme *th = meow_theme_get();
     const ncm_pal_t *pa  = ncm_palette(g_dark);
-    int sc = cur_song();
-    const ncm_song_t *s = (sc >= 0) ? &g_st.songs[sc] : NULL;
-    const char *nm = s ? s->name : "暂无播放";
-    const char *ar = s ? s->art_name : "";
+    ncm_song_t sm;
+    int have = (cur_song_meta(&sm) == 0);
+    const char *nm = have ? sm.name : "暂无播放";
+    const char *ar = have ? sm.art_name : "";
 
     if (g_landscape) {
         meow_ui_text(g_info_x, g_title_y, ncm_text_fit(nm, g_info_w, 28), 28, th->onSurface);
@@ -204,7 +214,7 @@ static void plr_draw_dyn(void *ctx)
     /* 进度条 + 时间 */
     int pos = (int)player_manager_pos_ms();
     int dur = (int)player_manager_dur_ms();
-    if (dur <= 0 && sc >= 0) dur = (int)(g_st.songs[sc].duration_ms);
+    if (dur <= 0 && have) dur = (int)sm.duration_ms;
     int frac = dur > 0 ? (int)((int64_t)pos * 1000 / dur) : 0;
     if (frac < 0) frac = 0; if (frac > 1000) frac = 1000;
     char lp[16], rp[16];
@@ -302,11 +312,12 @@ void player_on_tap(int x, int y)
 
 void player_play_song(int idx)
 {
-    if (idx < 0 || idx >= g_st.song_count) return;
-    /* 二期：黑胶封面用真实专辑图（song_detail 的 al.picUrl，经 ncm_cache 缓存/限幅），
-     * 无 al.picUrl（如无版权占位）时回落歌单封面。 */
-    const ncm_song_t *s = &g_st.songs[idx];
-    const char *cover = (s && s->al_pic[0]) ? s->al_pic : g_st.cover_url;
+    if (idx < 0 || idx >= g_st.track_ids_count) return;
+    /* 黑胶封面用真实专辑图（song_detail 的 al.picUrl，经 ncm_cache 缓存/限幅）；
+     * 滑窗未物化（占位行直点）时回落歌单封面，元数据由播放线程物化后快照接管（§17）。 */
+    ncm_song_t s;
+    const char *cover = (appstate_song_copy(idx, &s) == 0 && s.al_pic[0])
+                        ? s.al_pic : g_st.cover_url;
     player_manager_play(idx);
     appstate_set_playing_song(idx, cover);
     cover_request(cover);
@@ -338,13 +349,16 @@ void player_tick(uint64_t now)
 
     if (sc != g_last_song) {
         g_last_song = sc;
-        /* 切歌（next/prev/自动顺延）→ 请求新曲专辑封面（黑胶盘换图） */
-        if (sc >= 0) {
-            const ncm_song_t *s2 = &g_st.songs[sc];
-            cover_request(s2->al_pic[0] ? s2->al_pic : g_st.cover_url);
-        }
         meow_ui_invalidate(g_dyn_r.x, g_dyn_r.y, g_dyn_r.w, g_dyn_r.h);   /* 歌名/歌手变 */
     }
+    /* 元数据 id 变化（含快照滞后 settle：切歌瞬间快照仍是旧曲，play 线程更新后此处纠正）→
+     * 请求新曲专辑封面（黑胶盘换图）+ 刷动态带。 */
+    ncm_song_t s2;
+    if (sc >= 0 && cur_song_meta(&s2) == 0 && strcmp(s2.id, g_last_meta_id) != 0) {
+        ncm_strlcpy(g_last_meta_id, s2.id, sizeof g_last_meta_id);
+        cover_request(s2.al_pic[0] ? s2.al_pic : g_st.cover_url);
+        meow_ui_invalidate(g_dyn_r.x, g_dyn_r.y, g_dyn_r.w, g_dyn_r.h);
+    }
     if (cover_changed()) {
         cover_ack();
         meow_ui_invalidate(g_disc_r.x, g_disc_r.y, g_disc_r.w, g_disc_r.h);
@@ -376,6 +390,7 @@ static void plr_page_create(meow_view *v, void *ctx)
     g_custom_dyn  = meow_draw_custom_register(11, g_dyn_r.x, g_dyn_r.y, g_dyn_r.w, g_dyn_r.h,
                                               plr_draw_dyn, NULL);
     g_last_pos_ms = -1; g_last_state = -1; g_last_line = -1; g_last_song = -1;
+    g_last_meta_id[0] = 0;
 }
 
 static void plr_page_enter(meow_view *v, void *ctx)

patch_v2/ncm_app/app/ui/playlist.c

@@ -25,7 +25,9 @@ static char         g_title[256];
 static volatile int g_load_err;
 static int          g_press_row, g_press_delta, g_dragging, g_drag_last_y;
 
-/* 歌单详情加载后台 worker（大歌单可达数十秒，不能占 UI 线程）。 */
+/* 歌单详情加载后台 worker（大歌单可达数十秒，不能占 UI 线程）。
+ * §17 滑动窗口：worker 两种任务——①首屏（g_ens_first=1）：重建 trackIds 索引 + 物化首段；
+ * ②滑窗补载：物化视口区间 [g_ens_lo,g_ens_hi)（ensure_range，盘缓存优先）。 */
 static pthread_mutex_t g_plmu = PTHREAD_MUTEX_INITIALIZER;
 static pthread_t       g_plthr;
 static int             g_plthr_on;
@@ -33,8 +35,9 @@ static volatile int    g_plgen;
 static int             g_placked;
 static volatile int    g_plloading;
 static volatile int    g_plloaded_idx;
-static volatile int    g_ploffset;   /* 本页起始下标（0=首屏重头；>0=触底追加） */
-static volatile int    g_pl_more;    /* 1=尚有下一页可加载（song_count < track_ids_count 且未到 NCM_SONG_MAX） */
+static volatile int    g_ens_lo, g_ens_hi;   /* 滑窗补载目标区间（全局下标） */
+static volatile int    g_ens_first;          /* 1=首屏重头（offset=0） */
+static volatile int    g_ens_err;            /* 最近一次滑窗补载错误（0=ok；首屏错误走 g_load_err） */
 
 static void pl_drag_reset(void)
 {
@@ -44,15 +47,24 @@ static void pl_drag_reset(void)
 static int pl_src2(int idx, meow_list_item *out, void *ctx)
 {
     (void)ctx;
-    if (idx < 0 || idx >= g_st.song_count) return 0;
-    ncm_song_t *s = &g_st.songs[idx];
+    if (idx < 0 || idx >= g_st.track_ids_count) return 0;
+    static ncm_song_t s_s;   /* 锁内拷贝驻留缓冲（src2 由 UI 线程串行调用，title 指针对当次绘制有效） */
+    if (appstate_song_copy(idx, &s_s) != 0) {
+        /* 占位行：滑窗未覆盖/未物化（后台 ensure 完成后自愈）。 */
+        out->icon_kind = MEOW_LIST_ICON_NONE;
+        out->title = "···";
+        out->subtitle = "加载中";
+        out->right  = MEOW_LIST_RIGHT_ARROW;
+        out->on = 0; out->enabled = 1;
+        return 1;
+    }
     static char sub[256];
-    if (s->art_name[0] && s->album_name[0]) snprintf(sub, sizeof sub, "%s · %s", s->art_name, s->album_name);
-    else if (s->art_name[0])                snprintf(sub, sizeof sub, "%s", s->art_name);
-    else if (s->album_name[0])              snprintf(sub, sizeof sub, "%s", s->album_name);
-    else                                    snprintf(sub, sizeof sub, "-");
+    if (s_s.art_name[0] && s_s.album_name[0]) snprintf(sub, sizeof sub, "%s · %s", s_s.art_name, s_s.album_name);
+    else if (s_s.art_name[0])                 snprintf(sub, sizeof sub, "%s", s_s.art_name);
+    else if (s_s.album_name[0])               snprintf(sub, sizeof sub, "%s", s_s.album_name);
+    else                                      snprintf(sub, sizeof sub, "-");
     out->icon_kind = MEOW_LIST_ICON_NONE;
-    out->title = s->name;
+    out->title = s_s.name;
     out->subtitle = sub;
     out->right  = MEOW_LIST_RIGHT_ARROW;
     out->on = 0; out->enabled = 1;
@@ -64,12 +76,12 @@ static void pl_row_bg(void *ctx)
 {
     (void)ctx;
     if (meow_ui_activity_active() != ACT_PLAYLIST) return;
-    if (g_load_err != 0 || g_st.song_count == 0) return;
+    if (g_load_err != 0 || g_st.track_ids_count == 0) return;
     const meow_theme *th = meow_theme_get();
     int item  = APP_ROW_H;
     int off   = meow_listview_scroll(g_list);
     int first = off / item, last = (off + r_list.h) / item + 1;
-    if (last > g_st.song_count) last = g_st.song_count;
+    if (last > g_st.track_ids_count) last = g_st.track_ids_count;
     for (int i = first; i < last; i++) {
         int ry = r_list.y + (i * item - off) + 1, th2 = item - 2;
         if (ry < r_list.y || ry + th2 > r_list.y + r_list.h) continue;   /* 只画完整落在视口内的行 */
@@ -100,7 +112,7 @@ static void pl_draw(void *ctx)
     int nmx = r_cov.x + r_cov.w + 12;
     char meta[256];
     if (pl) snprintf(meta, sizeof meta, "创建者 · %d 首", pl->track_count);
-    else    snprintf(meta, sizeof meta, "曲目 %d 首", g_st.song_count);
+    else    snprintf(meta, sizeof meta, "曲目 %d 首", g_st.track_ids_count);
     /* 歌单名（截断到卡片右缘：按 UTF-8 字符合法边界逐字累加测宽）。 */
     {
         int maxw = r_card.x + r_card.w - 16 - nmx;
@@ -131,11 +143,11 @@ static void pl_draw(void *ctx)
     meow_ui_fill_rect(r_cmt.x + r_cmt.w / 2 + 34, r_cmt.y + 10, 6, 6, pa->red);
 
     /* 曲目行：红 mini-vinyl 缩略 + 按压红条（文本由 listview z=10 画） */
-    if (g_load_err == 0 && g_st.song_count > 0) {
+    if (g_load_err == 0 && g_st.track_ids_count > 0) {
         int item  = APP_ROW_H, isz = 24;
         int off   = meow_listview_scroll(g_list);
         int first = off / item, last = (off + r_list.h) / item + 1;
-        if (last > g_st.song_count) last = g_st.song_count;
+        if (last > g_st.track_ids_count) last = g_st.track_ids_count;
         for (int i = first; i < last; i++) {
             int ry = r_list.y + (i * item - off) + 1, th2 = item - 2;
             if (ry < r_list.y || ry + th2 > r_list.y + r_list.h) continue;
@@ -154,7 +166,7 @@ static void pl_draw_empty(void *ctx)
 {
     (void)ctx;
     if (meow_ui_activity_active() != ACT_PLAYLIST) return;
-    if (g_load_err == 0 && g_st.song_count != 0) return;
+    if (g_load_err == 0 && g_st.track_ids_count != 0) return;
     if (g_plloading) { ncm_draw_empty(r_list, "加载中", "正在加载曲目..."); return; }
     if (g_load_err == NCM_ERR_AUTH) ncm_draw_empty(r_list, "登录已过期", "请重新登录");
     else if (g_load_err)            ncm_draw_empty(r_list, "加载失败", "点按重试");
@@ -166,18 +178,22 @@ static void pl_draw_footer(void *ctx)
     (void)ctx;
     if (meow_ui_activity_active() != ACT_PLAYLIST) return;
     if (g_load_err != 0) return;
-    int total = (g_st.active_playlist >= 0 && g_st.active_playlist < g_st.playlist_count)
-              ? g_st.playlists[g_st.active_playlist].track_count : g_st.song_count;
+    int total = g_st.track_ids_count;
+    if (total <= 0) return;
+    /* 视口位置 / 总数（滑窗模型下「已物化数」无用户意义，视口区间更直观） */
+    int first = meow_listview_scroll(g_list) / APP_ROW_H + 1;
+    int last  = first + r_list.h / APP_ROW_H;
+    if (last > total) last = total;
     char foot[96];
-    snprintf(foot, sizeof foot, "%d/%d 首", g_st.song_count, total);
+    snprintf(foot, sizeof foot, "%d-%d / %d 首", first, last, total);
     ncm_draw_footer(r_cont, foot);
 }
 
-/* apply：reset_scroll=1 时列表回顶并清选中（首屏/刷新）；0=保持当前滚动（触底追加，防跳顶）。 */
+/* apply：reset_scroll=1 时列表回顶并清选中（首屏/刷新）；0=保持当前滚动（滑窗补载，防跳顶）。 */
 static void pl_apply(int reset_scroll)
 {
     if (g_list) {
-        meow_listview_set_count(g_list, g_st.song_count);
+        meow_listview_set_count(g_list, g_st.track_ids_count);   /* 全量行数（占位行兜底未物化区） */
         if (reset_scroll) { meow_listview_set_scroll(g_list, 0); meow_listview_set_sel(g_list, -1); }
     }
     if (g_tb && g_st.active_playlist >= 0 && g_st.active_playlist < g_st.playlist_count) {
@@ -193,16 +209,16 @@ static void *playlist_worker(void *arg)
 {
     (void)arg;
     int my_idx = g_st.active_playlist;
-    int off = g_ploffset;
+    int first = g_ens_first;
+    int lo = g_ens_lo, hi = g_ens_hi;
     int rc;
     if (g_host_mock) rc = 0;
     else if (my_idx < 0) rc = NCM_ERR_ARG;
-    else rc = appstate_load_playlist_songs_page(my_idx, off, NCM_SONG_BATCH);
+    else if (first) rc = appstate_load_playlist_songs_page(my_idx, 0, NCM_SONG_BATCH);
+    else            rc = appstate_song_ensure_range(lo, hi);
     pthread_mutex_lock(&g_plmu);
-    g_load_err = rc;
-    /* 本页后仍有多余 trackIds（tail 未到）且未到内存上限 → 还有下一页；否则到屏尾。 */
-    g_pl_more = (rc == NCM_OK) && (g_st.song_count < g_st.track_ids_count) &&
-                (g_st.song_count < NCM_SONG_MAX);
+    if (first) g_load_err = rc;          /* 首屏失败 → 整页空态（点按重试） */
+    else       g_ens_err  = rc;          /* 补载失败 → snack + 占位行保留（滚动/点按再试） */
     g_plloading = 0;
     g_plloaded_idx = my_idx;
     g_plgen++;
@@ -210,19 +226,23 @@ static void *playlist_worker(void *arg)
     return NULL;
 }
 
-/* 触底加载下一页：仅当仍有下一页、未在载、未失败、未到 NCM_SONG_MAX 时发。 */
-static void pl_maybe_load_more(void)
+/* 视口驱动滑窗补载：视口 ±24 行有未物化槽位 → 发 ensure worker（已在载/失败态/宿主 mock 不发）。 */
+static void pl_maybe_ensure(void)
 {
     if (g_plthr_on || g_host_mock) return;
-    if (g_load_err != 0) return;                 /* 失败态：走点按重试，不自动循环 */
-    if (!g_pl_more) return;
-    if (g_st.song_count >= NCM_SONG_MAX) return;
-    /* 视口底接近列表底（最后一行即将可见即预取） */
-    int list_px = g_st.song_count * APP_ROW_H;
-    int max_scroll = list_px - r_list.h;
-    if (max_scroll < 0) max_scroll = 0;
-    if (meow_listview_scroll(g_list) < max_scroll - APP_ROW_H * 2) return;
-    g_ploffset = g_st.song_count;                /* 下一页起始 = 已物化数 */
+    if (g_load_err != 0) return;                 /* 首屏失败态：走点按重试 */
+    int total = g_st.track_ids_count;
+    if (total <= 0) return;
+    int scroll = meow_listview_scroll(g_list);
+    int first  = scroll / APP_ROW_H;
+    int last   = (scroll + r_list.h) / APP_ROW_H + 1;
+    int lo = first - 24, hi = last + 24;
+    if (lo < 0) lo = 0;
+    if (hi > total) hi = total;
+    if (lo >= hi) return;
+    if (appstate_range_loaded(lo, hi)) return;   /* 已物化：无操作（窗口原地不动） */
+    g_ens_lo = lo; g_ens_hi = hi;
+    g_ens_first = 0;
     g_plloading = 1;
     g_plthr_on = 1;
     if (pthread_create(&g_plthr, NULL, playlist_worker, NULL) != 0) {
@@ -232,13 +252,11 @@ static void pl_maybe_load_more(void)
 
 void playlist_refresh(void)
 {
-    if (g_host_mock) { g_load_err = 0; g_pl_more = 0; pl_apply(1); return; }
+    if (g_host_mock) { g_load_err = 0; g_ens_err = 0; pl_apply(1); return; }
     if (g_plthr_on) return;
     g_load_err = 0;
-    g_st.song_count = 0;
-    g_st.track_ids_count = 0;
-    g_ploffset = 0;
-    g_pl_more = 0;
+    g_ens_err = 0;
+    g_ens_first = 1;                             /* 首屏：重建索引 + 物化首段 */
     g_plloading = 1;
     g_plthr_on = 1;
     if (pthread_create(&g_plthr, NULL, playlist_worker, NULL) != 0) {
@@ -257,20 +275,15 @@ void playlist_tick(uint64_t now)
     g_plloading = 0;
     if (g_plloaded_idx != g_st.active_playlist) { playlist_refresh(); return; }
     if (g_load_err != 0) {
-        if (g_ploffset == 0) {
-            g_st.song_count = 0;                 /* 首屏失败 → 整页空态（点按重试） */
-            pl_apply(1);
-        } else {
-            /* 追加失败 → 保留已载歌曲 + 重置 g_pl_more（触底/点击可重试） */
-            ncm_snack("加载失败");
-            g_load_err = 0;
-            g_pl_more = (g_st.song_count < g_st.track_ids_count) &&
-                        (g_st.song_count < NCM_SONG_MAX);
-            pl_apply(0);
-        }
+        g_st.track_ids_count = 0;                /* 首屏失败 → 整页空态（点按重试） */
+        pl_apply(1);
         return;
     }
-    pl_apply(g_ploffset == 0);   /* 首屏回顶；触底追加保持滚动 */
+    if (g_ens_err != 0) {
+        ncm_snack("加载失败");
+        g_ens_err = 0;                           /* 占位行保留：滚动/点按触发重试 */
+    }
+    pl_apply(g_ens_first);
 }
 
 void playlist_open(int idx)
@@ -307,7 +320,7 @@ int playlist_on_tap(int x, int y)
         playlist_refresh();
         return 1;
     }
-    if (g_st.song_count == 0) return 0;   /* 空歌单（无失败）：不重试 */
+    if (g_st.track_ids_count == 0) return 0;   /* 空歌单（无失败）：不重试 */
     if (meow_widget_hit(g_list, x, y)) {
         /* 误触修复：小拖动（<SWIPE_THRESH）会先滚动列表、release 又被 SDK 判成 TAP，旧的
          * meow_listview_hit(x,y) 用“释放点 + 更新后的 scroll”命中 → 打到“已移动到手指下”的行，
@@ -317,7 +330,7 @@ int playlist_on_tap(int x, int y)
         int row = (g_press_row >= 0) ? g_press_row : meow_listview_hit(g_list, x, y);
         pl_drag_reset();
         if (row < 0 || was_drag) return 1;
-        player_play_song(row);
+        player_play_song(row);   /* 占位行也可点：播放线程经 appstate_song_fetch 物化该曲 */
         return 1;
     }
     return 0;
@@ -326,7 +339,7 @@ int playlist_on_tap(int x, int y)
 void playlist_touch_down(int x, int y)
 {
     pl_drag_reset();
-    if (g_load_err != 0 || g_st.song_count == 0) return;
+    if (g_load_err != 0 || g_st.track_ids_count == 0) return;
     if (meow_widget_hit(g_list, x, y)) {
         int row = meow_listview_hit(g_list, x, y);
         if (row >= 0) g_press_row = row;
@@ -350,20 +363,20 @@ void playlist_touch_move(int x, int y)
     meow_listview_scroll_by(g_list, -dy);
     if (meow_listview_scroll(g_list) != before) {
         meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
-        pl_maybe_load_more();
+        pl_maybe_ensure();
     }
 }
 
 void playlist_swipe(int dir, int dist)
 {
     if (dir != MEOW_SWIPE_UP && dir != MEOW_SWIPE_DOWN) return;
-    if (g_load_err != 0 || g_st.song_count == 0) return;
+    if (g_load_err != 0 || g_st.track_ids_count == 0) return;
     int del = (dir == MEOW_SWIPE_UP) ? dist : -dist;
     int before = meow_listview_scroll(g_list);
     meow_listview_scroll_by(g_list, del);
     if (meow_listview_scroll(g_list) != before) {
         meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
-        pl_maybe_load_more();
+        pl_maybe_ensure();
     }
 }
 

patch_v2/ncm_app/app/ui/search.c

@@ -94,7 +94,9 @@ static void sr_apply(void)
     meow_ui_paint_full();
 }
 
-/* 后台 worker：唯一网络调用（cloudsearch），UI 不卡。 */
+/* 后台 worker：唯一网络调用（cloudsearch），UI 不卡。
+ * §17：结果集（≤NCM_SEARCH_MAX，远小于窗口）经 appstate_adopt_songs 收编为窗口 base=0
+ * 播放上下文（song_ids/track_ids_count 同步），播放/上下一首对结果集生效。 */
 static void *search_worker(void *arg)
 {
     (void)arg;
@@ -104,12 +106,12 @@ static void *search_worker(void *arg)
                                  g_st.songs, NCM_SEARCH_MAX, &n);
     pthread_mutex_lock(&g_mu);
     if (rc == NCM_OK) {
+        appstate_adopt_songs(n);     /* 收编 songs[0..n) 为窗口（写侧在锁内） */
         g_st.search_count = n;
-        g_st.song_count = n;         /* 结果集作为当前播放上下文 */
         g_st.search_err = 0;
     } else {
+        appstate_adopt_songs(0);
         g_st.search_count = 0;
-        g_st.song_count = 0;
         g_st.search_err = rc;
     }
     g_loading = 0;