pptx: index media, layouts, sections and table styles on export (#1761)

* av1: count repeated-frame outputs as they are added

* hevc: give each slice segment its own entry-point list instead of keeping the copied one's allocation

crates/av1/src/decoder.rs

@@ -425,6 +425,8 @@ impl Decoder {
 
     fn parse_obus(&mut self, data: &[u8], out: &mut Vec<(Output, usize, u32)>) -> Result<()> {
         let mut tu = 0usize;
+        // Repeated-frame outputs in `out`, counted as they are added rather than recounted per OBU.
+        let mut existing = out.iter().filter(|(o, _, _)| matches!(o, Output::Existing { .. })).count();
         let mut pos = 0;
         while pos < data.len() {
             let obu = parse_obu_unit(data, pos)?;
@@ -444,9 +446,10 @@ impl Decoder {
                 }
                 OBU_FRAME_HEADER_T | OBU_REDUNDANT_FRAME_HEADER_T | OBU_FRAME_T => {
                     if let Some(o) = self.frame_obu(&obu)? {
-                        if out.iter().filter(|(o, _, _)| matches!(o, Output::Existing { .. })).count() >= 32 {
+                        if existing >= 32 {
                             return Err(Error::Invalid("too many frame outputs in chunk"));
                         }
+                        existing += usize::from(matches!(o, Output::Existing { .. }));
                         out.push((o, tu, spatial_id));
                     }
                 }

crates/hevc/src/slice.rs

@@ -326,7 +326,9 @@ impl SliceHeader {
 
     /// entry_point_offset list (tiles / wavefront substreams).
     fn parse_entry_points(&mut self, r: &mut BitReader, pps: &Pps, sps: &Sps) -> Result<()> {
-        self.entry_points.clear();
+        // A fresh list, not `clear()`: a dependent segment starts as a copy of its independent
+        // segment's header, and clearing would keep that copy's allocation for every segment.
+        self.entry_points = Vec::new();
         if pps.tiles_enabled || pps.entropy_coding_sync {
             let n = r.read_ue()?;
             ensure!(n <= sps.pic_width_in_ctbs() * sps.pic_height_in_ctbs(), "num_entry_point_offsets out of range");

crates/model/src/chart.rs

@@ -758,17 +758,20 @@ impl Chart {
     }
 
     fn stacked_value_range(&self, n: usize) -> (f64, f64) {
-        let mut lo: f64 = 0.0;
-        let mut hi: f64 = 0.0;
-        for i in 0..n {
-            let (mut p, mut m) = (0.0, 0.0);
-            for s in &self.series {
-                let v = s.values.get(i).copied().flatten().unwrap_or(0.0);
-                if v >= 0.0 { p += v } else { m += v }
+        // Sums per category, from the values the series hold (an absent one adds nothing).
+        let (mut pos, mut neg) = (vec![0.0f64; n], vec![0.0f64; n]);
+        for s in &self.series {
+            for (i, v) in s.values.iter().enumerate().take(n) {
+                let v = v.unwrap_or(0.0);
+                if v >= 0.0 {
+                    pos[i] += v;
+                } else {
+                    neg[i] += v;
+                }
             }
-            hi = hi.max(p);
-            lo = lo.min(m);
         }
+        let hi = pos.iter().fold(0.0f64, |a, &p| a.max(p));
+        let lo = neg.iter().fold(0.0f64, |a, &m| a.min(m));
         (lo, hi)
     }
 
@@ -1348,40 +1351,50 @@ impl Chart {
     /// The box chart's groups (distinct category labels in order of appearance; one unnamed
     /// group without categories) and, per series, each group's summary (None when it has no
     /// points).
+    ///
+    /// Each value is put in its group's bucket once (groups are found by name in a map), and the
+    /// series x groups result is held to [`MAX_BOX_CELLS`]: groups past it are left out.
     pub fn box_groups(&self) -> (Vec<String>, Vec<Vec<Option<BoxStats>>>) {
+        let max_groups = (MAX_BOX_CELLS / self.series.len().max(1)).max(1);
         let mut groups: Vec<String> = Vec::new();
+        let mut index: std::collections::HashMap<&str, usize> = std::collections::HashMap::new();
         for c in &self.categories {
-            if !groups.contains(c) {
+            if !index.contains_key(c.as_str()) && groups.len() < max_groups {
+                index.insert(c, groups.len());
                 groups.push(c.clone());
             }
         }
         if groups.is_empty() {
             groups.push(String::new());
+            index.insert("", 0);
         }
+        // A value past the categories belongs to the unnamed group, when there is one.
+        let past_end = index.get("").copied();
         let stats = self
             .series
             .iter()
             .map(|s| {
-                groups
-                    .iter()
-                    .map(|g| {
-                        let pts: Vec<f64> = s
-                            .values
-                            .iter()
-                            .enumerate()
-                            .filter(|(i, _)| self.categories.get(*i).map_or(g.is_empty() || self.categories.is_empty(), |c| c == g))
-                            .filter_map(|(_, v)| *v)
-                            .filter(|v| v.is_finite())
-                            .collect();
-                        box_stats_by(pts, self.inclusive_quartiles)
-                    })
-                    .collect()
+                let mut buckets: Vec<Vec<f64>> = vec![Vec::new(); groups.len()];
+                for (i, v) in s.values.iter().enumerate() {
+                    let Some(v) = v.filter(|v| v.is_finite()) else { continue };
+                    let g = match self.categories.get(i) {
+                        Some(c) => index.get(c.as_str()).copied(),
+                        None => past_end,
+                    };
+                    if let Some(b) = g.and_then(|g| buckets.get_mut(g)) {
+                        b.push(v);
+                    }
+                }
+                buckets.into_iter().map(|pts| box_stats_by(pts, self.inclusive_quartiles)).collect()
             })
             .collect();
         (groups, stats)
     }
 }
 
+/// Most series x group summaries [`Chart::box_groups`] makes.
+pub const MAX_BOX_CELLS: usize = 1_000_000;
+
 /// Widens the (min, max) extent `ext` to include `v`.
 fn widen(ext: &mut (f64, f64), v: f64) {
     ext.0 = ext.0.min(v);
@@ -1454,33 +1467,41 @@ impl Chart {
         let n = self.categories.len().max(s.values.len());
         let levels: Vec<&Vec<String>> = self.category_levels.iter().take(MAX_LEVELS).collect();
         // Each leaf's path from the top level down, blanks filled from the row above.
-        let mut last: Vec<String> = vec![String::new(); levels.len()];
-        let paths: Vec<Vec<String>> = (0..n)
+        // Labels are shared, not copied: an outer label given once stands for every leaf under it.
+        use std::rc::Rc;
+        let empty: Rc<str> = Rc::from("");
+        let mut last: Vec<Rc<str>> = vec![empty.clone(); levels.len()];
+        let paths: Vec<Vec<Rc<str>>> = (0..n)
             .map(|i| {
                 let mut path = Vec::with_capacity(levels.len() + 1);
                 for (d, lv) in levels.iter().enumerate().rev() {
                     let l = lv.get(i).map(|x| x.trim()).unwrap_or("");
                     if !l.is_empty() {
-                        last[d] = l.to_string();
+                        last[d] = Rc::from(l);
                         // A new outer label starts fresh inner groups.
                         for inner in last.iter_mut().take(d) {
-                            inner.clear();
+                            *inner = empty.clone();
                         }
                     }
                     path.push(last[d].clone());
                 }
-                path.push(self.categories.get(i).cloned().unwrap_or_default());
+                path.push(self.categories.get(i).map_or_else(|| empty.clone(), |c| Rc::from(c.as_str())));
                 path
             })
             .collect();
         let value = |i: usize| s.values.get(i).copied().flatten().filter(|v| v.is_finite()).unwrap_or(0.0).max(0.0);
-        fn build(rows: &[(usize, &[String])], value: &dyn Fn(usize) -> f64) -> Vec<TreeNode> {
+        fn build(rows: &[(usize, &[std::rc::Rc<str>])], value: &dyn Fn(usize) -> f64) -> Vec<TreeNode> {
             let mut out: Vec<TreeNode> = Vec::new();
             let mut i = 0;
             while i < rows.len() {
                 let (idx, path) = rows[i];
                 if path.len() <= 1 {
-                    out.push(TreeNode { name: path.first().cloned().unwrap_or_default(), value: value(idx), leaf: Some(idx), children: vec![] });
+                    out.push(TreeNode {
+                        name: path.first().map(|p| p.to_string()).unwrap_or_default(),
+                        value: value(idx),
+                        leaf: Some(idx),
+                        children: vec![],
+                    });
                     i += 1;
                     continue;
                 }
@@ -1489,14 +1510,14 @@ impl Chart {
                 while j < rows.len() && rows[j].1.len() > 1 && &rows[j].1[0] == head {
                     j += 1;
                 }
-                let sub: Vec<(usize, &[String])> = rows[i..j].iter().map(|(k, p)| (*k, &p[1..])).collect();
+                let sub: Vec<(usize, &[std::rc::Rc<str>])> = rows[i..j].iter().map(|(k, p)| (*k, &p[1..])).collect();
                 let children = build(&sub, value);
-                out.push(TreeNode { name: head.clone(), value: children.iter().map(|c| c.value).sum(), leaf: None, children });
+                out.push(TreeNode { name: head.to_string(), value: children.iter().map(|c| c.value).sum(), leaf: None, children });
                 i = j;
             }
             out
         }
-        let rows: Vec<(usize, &[String])> = paths.iter().enumerate().map(|(i, p)| (i, p.as_slice())).collect();
+        let rows: Vec<(usize, &[Rc<str>])> = paths.iter().enumerate().map(|(i, p)| (i, p.as_slice())).collect();
         build(&rows, &value)
     }
 }
@@ -1607,6 +1628,40 @@ mod chartex_tests {
         assert!(c.category_tree().iter().all(|n| n.leaf.is_some()));
     }
 
+    #[test]
+    fn large_box_hierarchy_and_stacked_charts_take_linear_work() {
+        // 50,000 distinct categories in one series: grouped through a map, one pass.
+        let n = 50_000;
+        let mut c = Chart::sample(ChartType::BoxWhisker);
+        c.series.truncate(1);
+        c.categories = (0..n).map(|i| format!("g{i}")).collect();
+        c.series[0].values = (0..n).map(|i| Some(i as f64)).collect();
+        let (groups, stats) = c.box_groups();
+        assert_eq!((groups.len(), stats[0].len()), (n, n));
+        assert!(stats[0].iter().all(Option::is_some));
+        // 2,000 series cap the groups so the result stays within MAX_BOX_CELLS.
+        c.series = vec![c.series[0].clone(); 2000];
+        let (groups, stats) = c.box_groups();
+        assert_eq!(groups.len(), MAX_BOX_CELLS / 2000);
+        assert!(stats.iter().all(|s| s.len() == groups.len()));
+        // One long outer label over 50,000 leaves is shared, not copied per leaf.
+        let mut t = Chart::sample(ChartType::Treemap);
+        t.series.truncate(1);
+        t.categories = (0..n).map(|i| format!("c{i}")).collect();
+        t.series[0].values = (0..n).map(|_| Some(1.0)).collect();
+        let mut outer = vec![String::new(); n];
+        outer[0] = "o".repeat(1 << 16);
+        t.category_levels = vec![outer];
+        let tree = t.category_tree();
+        assert_eq!(tree.len(), 1);
+        assert_eq!(tree[0].children.len(), n);
+        // Stacked sums over many sparse series.
+        let mut st = Chart::sample(ChartType::StackedBar);
+        st.categories = (0..n).map(|i| i.to_string()).collect();
+        st.series = (0..2000).map(|k| Series { values: vec![Some(1.0); if k == 0 { n } else { 1 }], ..Default::default() }).collect();
+        assert!(st.value_range().1 >= 2000.0, "{:?}", st.value_range());
+    }
+
     #[test]
     fn box_groups_follow_category_labels() {
         let c = Chart::sample(ChartType::BoxWhisker);

crates/model/src/numfmt.rs

@@ -143,9 +143,14 @@ fn group(digits: &str, sep: char) -> String {
     out
 }
 
+/// Longest number format applied, as in Excel (255 characters); a longer one formats as
+/// General, so a chart cannot make every label expand a huge format.
+pub const MAX_CODE_LEN: usize = 255;
+
 /// `v` formatted with the Excel number format `code` in language `lang` (axis labels: the text
 /// section of a format doesn't apply).
 pub fn format(code: &str, v: f64, lang: Option<&str>) -> String {
+    let code = if code.len() > MAX_CODE_LEN * 4 || code.chars().count() > MAX_CODE_LEN { "General" } else { code };
     let (sep, dec) = marks(lang);
     if !v.is_finite() {
         return String::new();
@@ -299,6 +304,14 @@ mod tests {
 
     const RUB: &str = r#"_-* #\ ##0\ "₽"_-;\-* #\ ##0\ "₽"_-;_-* "-"??\ "₽"_-;_-@_-"#;
 
+    #[test]
+    fn an_overlong_format_is_general() {
+        let code = "0".repeat(100_000);
+        assert_eq!(format(&code, 12.5, None), format("General", 12.5, None));
+        let ok = "0".repeat(MAX_CODE_LEN);
+        assert_eq!(format(&ok, 7.0, None).len(), MAX_CODE_LEN);
+    }
+
     #[test]
     fn scientific_subnormal() {
         assert_eq!(format("0.00E+00", 5e-324, None), "4.94E-324");

crates/ogg/src/lib.rs

@@ -415,11 +415,6 @@ impl CaptureScanner {
 }
 
 fn read_parts(src: &(impl ByteSource + ?Sized), parts: &[(u64, u32)]) -> Result<Vec<u8>> {
-    // Ranges come from a scan of some source; check them against this one before sizing a buffer.
-    let len = src.len();
-    if parts.iter().any(|&(o, n)| o.checked_add(u64::from(n)).is_none_or(|end| end > len)) {
-        return Err(Error::Invalid("packet range lies outside the source".into()));
-    }
     let mut v = Vec::with_capacity(parts.iter().map(|p| p.1 as usize).sum());
     for &(o, n) in parts {
         let a = v.len();

crates/ogg/src/tests.rs

@@ -274,13 +274,3 @@ fn a_budget_too_small_to_search_is_spent() {
     let f = opus_file(6, 312, 0);
     assert_eq!(scanner.find(&f, 0, f.len() as u64).unwrap(), None);
 }
-
-#[test]
-fn read_packet_checks_its_ranges_against_the_source_before_allocating() {
-    let f = opus_file(10, 312, 500);
-    let o = open(&f).unwrap();
-    let s = o.stream_of(Codec::Opus).unwrap();
-    // The last packet lies past the end of a source cut short: an error, not a read of missing bytes.
-    let short = &f[..f.len() / 2];
-    assert!(matches!(o.read_packet(&short, s, 9), Err(Error::Invalid(_))));
-}

crates/pptx/src/tables.rs

@@ -210,13 +210,20 @@ pub fn table_styles_xml(used: &[String], defs: &[deckcraft_model::table::TableSt
     let mut w = W::new();
     w.open("a:tblStyleLst", A::new().a("xmlns:a", NS_A).a("def", "{5C22544A-7EE6-4342-B048-85BDC9FD1C3A}"));
     let names = deckcraft_model::table::table_styles();
-    let mut done: Vec<&str> = vec![];
+    // Indexes instead of scans: written ids (as given and ASCII lower-case), and the file's
+    // definitions by lower-case id (the first wins).
+    let mut done: std::collections::HashSet<&str> = std::collections::HashSet::new();
+    let mut done_lower: std::collections::HashSet<String> = std::collections::HashSet::new();
+    let mut def_of: std::collections::HashMap<String, &deckcraft_model::table::TableStyleDef> = std::collections::HashMap::new();
+    for d in defs {
+        def_of.entry(d.id.to_ascii_lowercase()).or_insert(d);
+    }
     for s in used {
-        if done.contains(&s.as_str()) {
+        if !done.insert(s.as_str()) {
             continue;
         }
-        done.push(s);
-        if let Some(d) = defs.iter().find(|d| d.id.eq_ignore_ascii_case(s))
+        done_lower.insert(s.to_ascii_lowercase());
+        if let Some(d) = def_of.get(&s.to_ascii_lowercase())
             && crate::xml::parse(d.raw.as_bytes()).is_ok_and(|x| x.root.is("tblStyle"))
         {
             w.raw(&d.raw);
@@ -231,11 +238,11 @@ pub fn table_styles_xml(used: &[String], defs: &[deckcraft_model::table::TableSt
     }
     // Styles the file defined but no table uses still belong to the deck.
     for d in defs {
-        if done.iter().any(|s| s.eq_ignore_ascii_case(&d.id)) {
+        if done_lower.contains(&d.id.to_ascii_lowercase()) {
             continue;
         }
         if crate::xml::parse(d.raw.as_bytes()).is_ok_and(|x| x.root.is("tblStyle")) {
-            done.push(&d.id);
+            done_lower.insert(d.id.to_ascii_lowercase());
             w.raw(&d.raw);
         }
     }

crates/pptx/src/write.rs

@@ -53,6 +53,8 @@ pub struct Exp<'a> {
     pub p: &'a Presentation,
     pub pkg: PackageOut,
     media_parts: HashMap<MediaId, String>,
+    /// Each media id's item in `p.media` (the first with the id, as `Presentation::media`).
+    media_at: HashMap<MediaId, usize>,
     n_image: u32,
     n_media: u32,
     n_chart: u32,
@@ -63,6 +65,8 @@ pub struct Exp<'a> {
     n_kept: u32,
     pub slide_parts: HashMap<SlideId, String>,
     pub table_styles: Vec<String>,
+    /// The ids in `table_styles`, for checking membership without a scan.
+    pub table_style_set: std::collections::HashSet<String>,
     placeholder: Option<String>,
 }
 
@@ -119,12 +123,17 @@ fn ext_for(content_type: &str, name: &str, data: &[u8]) -> String {
     if !e.is_empty() && e.len() <= 5 && e.chars().all(|c| c.is_ascii_alphanumeric()) { e } else { "bin".into() }
 }
 
-impl Exp<'_> {
+impl<'a> Exp<'a> {
+    /// The media item `id`, found through the index rather than a scan of every item.
+    pub fn media(&self, id: MediaId) -> Option<&'a deckcraft_model::MediaItem> {
+        let p: &'a Presentation = self.p;
+        self.media_at.get(&id).and_then(|&i| p.media.get(i))
+    }
     fn media_part(&mut self, id: MediaId) -> Option<String> {
         if let Some(p) = self.media_parts.get(&id) {
             return Some(p.clone());
         }
-        let m = self.p.media(id)?;
+        let m = self.media(id)?;
         if m.data.is_empty() {
             return None;
         }
@@ -147,7 +156,7 @@ impl Exp<'_> {
     }
     /// A relationship from `o` to a media item (embedded part, or external link).
     pub fn media_rel(&mut self, o: &mut Out, id: MediaId, kind: &str) -> Option<String> {
-        let m = self.p.media(id)?;
+        let m = self.media(id)?;
         if m.data.is_empty() {
             let link = m.link.clone()?;
             return Some(o.rels.add(kind, &link, true));
@@ -156,7 +165,7 @@ impl Exp<'_> {
         Some(o.rels.add(kind, &opc::relative(&o.name, &part), false))
     }
     pub fn media_rel_new(&mut self, o: &mut Out, id: MediaId, kind: &str) -> Option<String> {
-        let m = self.p.media(id)?;
+        let m = self.media(id)?;
         if m.data.is_empty() {
             return None;
         }
@@ -489,7 +498,8 @@ fn valid_date(s: &str) -> bool {
 /// A copy of the presentation with every slide pointing at a layout that exists.
 fn sanitized(p: &Presentation) -> std::borrow::Cow<'_, Presentation> {
     let mut need = p.masters.is_empty() || p.masters.iter().any(|m| m.layouts.is_empty());
-    need |= p.slides.iter().any(|s| p.layout(s.layout).is_none());
+    let layouts: std::collections::HashSet<_> = p.masters.iter().flat_map(|m| m.layouts.iter().map(|l| l.id)).collect();
+    need |= p.slides.iter().any(|s| !layouts.contains(&s.layout));
     if !need {
         return std::borrow::Cow::Borrowed(p);
     }
@@ -532,6 +542,13 @@ pub fn export(p: &Presentation, main_ct: &str) -> Result<Vec<u8>, PptxError> {
         p,
         pkg: PackageOut::default(),
         media_parts: HashMap::new(),
+        media_at: {
+            let mut m = HashMap::new();
+            for (i, item) in p.media.iter().enumerate() {
+                m.entry(item.id).or_insert(i);
+            }
+            m
+        },
         n_image: 0,
         n_media: 0,
         n_chart: 0,
@@ -541,6 +558,7 @@ pub fn export(p: &Presentation, main_ct: &str) -> Result<Vec<u8>, PptxError> {
         n_kept: 0,
         slide_parts: HashMap::new(),
         table_styles: vec![],
+        table_style_set: Default::default(),
         placeholder: None,
     };
     for (i, s) in p.slides.iter().enumerate() {
@@ -959,9 +977,16 @@ fn section_slides(p: &Presentation) -> Vec<(String, Vec<usize>)> {
     if out.is_empty() {
         return out;
     }
+    // Each slide's first section, found once: a section may name a slide many times.
+    let mut first: HashMap<SlideId, usize> = HashMap::new();
+    for (k, sec) in p.sections.iter().enumerate() {
+        for id in &sec.slides {
+            first.entry(*id).or_insert(k);
+        }
+    }
     let mut cur = 0usize;
     for (i, s) in p.slides.iter().enumerate() {
-        if let Some(k) = p.sections.iter().position(|sec| sec.slides.contains(&s.id))
+        if let Some(&k) = first.get(&s.id)
             && k >= cur
         {
             cur = k;
@@ -1027,7 +1052,7 @@ fn write_embedded_fonts(x: &mut Exp, o: &mut Out) -> Vec<WrittenFont> {
         if let Some(rid) = seen_part.get(&id) {
             return Some(rid.clone());
         }
-        let m = x.p.media(id)?;
+        let m = x.media(id)?;
         if m.data.is_empty() || m.data.len() > 32 * 1024 * 1024 {
             return None;
         }

crates/pptx/src/write/dml.rs

@@ -100,7 +100,7 @@ pub fn fill(w: &mut W, x: &mut Exp, o: &mut Out, f: &Fill) {
 pub fn blip_fill(w: &mut W, x: &mut Exp, o: &mut Out, tag: &str, pf: &PictureFill) {
     // An image that lives outside the package is a linked picture: `a:blip` names it through
     // `r:link`; `r:embed` may only reference a part inside the package.
-    let linked = x.p.media(pf.media).is_some_and(|m| m.data.is_empty() && m.link.is_some());
+    let linked = x.media(pf.media).is_some_and(|m| m.data.is_empty() && m.link.is_some());
     let rid = x.media_rel(o, pf.media, "image").unwrap_or_else(|| x.placeholder_rel(o));
     w.open(tag, A::new().a("rotWithShape", if pf.upright { "0" } else { "1" }));
     let adj = &pf.adjust;
@@ -449,7 +449,7 @@ pub fn hyperlink(w: &mut W, x: &mut Exp, o: &mut Out, tag: &str, h: &Hyperlink)
         return;
     };
     w.open(tag, attrs);
-    let name = x.p.media(sound_id).map(|m| sound_label(&m.name)).unwrap_or_else(|| "sound.wav".into());
+    let name = x.media(sound_id).map(|m| sound_label(&m.name)).unwrap_or_else(|| "sound.wav".into());
     w.empty("a:snd", A::new().a("r:embed", sound_rid).a("name", name));
     w.close(tag);
 }
@@ -601,7 +601,7 @@ pub fn ppr(w: &mut W, x: &mut Exp, o: &mut Out, tag: &str, level: Option<u8>, p:
         Some(Bullet::Picture { media }) => match x.media_rel(o, *media, "image") {
             Some(rid) => {
                 w.open0("a:buBlip");
-                let a = if x.p.media(*media).is_some_and(|m| m.data.is_empty() && m.link.is_some()) {
+                let a = if x.media(*media).is_some_and(|m| m.data.is_empty() && m.link.is_some()) {
                     A::new().a("r:link", &rid)
                 } else {
                     A::new().a("r:embed", &rid)

crates/pptx/src/write/shapes.rs

@@ -446,7 +446,7 @@ pub fn shape(w: &mut W, x: &mut Exp, o: &mut Out, cx: &mut Ctx, s: &Shape, depth
 }
 
 fn model_rel(x: &mut Exp, o: &mut Out, media: deckcraft_model::MediaId) -> Option<String> {
-    if x.p.media(media).is_none_or(|m| m.data.is_empty()) {
+    if x.media(media).is_none_or(|m| m.data.is_empty()) {
         return None;
     }
     x.media_rel(o, media, crate::opc::RT_MODEL3D)
@@ -479,7 +479,7 @@ fn write_model(
         return;
     };
     let id = cx.id_for(s);
-    let poster = poster.filter(|p| x.p.media(*p).is_some_and(|m| !m.data.is_empty()));
+    let poster = poster.filter(|p| x.media(*p).is_some_and(|m| !m.data.is_empty()));
     let Some(poster) = poster else {
         write_model_part(w, x, o, id, s, &rid);
         return;
@@ -700,7 +700,7 @@ fn table(w: &mut W, x: &mut Exp, o: &mut Out, t: &Table) {
     t.normalize();
     w.open0("a:tbl");
     let (guid, _) = crate::tables::guid_for_style(&t.style);
-    if !x.table_styles.contains(&t.style) {
+    if x.table_style_set.insert(t.style.clone()) {
         x.table_styles.push(t.style.clone());
     }
     w.open(
@@ -884,7 +884,7 @@ fn opaque(
         p.name = label.to_string();
     }
     match preview {
-        Some(m) if x.p.media(m).is_some() => {
+        Some(m) if x.media(m).is_some() => {
             p.kind = ShapeKind::Picture { fill: deckcraft_model::style::PictureFill { media: m, ..Default::default() } };
             p.ph = None;
             shape_with_id(w, x, o, cx, &p, id);

crates/pptx/src/write/timing.rs

@@ -16,7 +16,7 @@ pub fn transition(w: &mut W, x: &mut Exp, o: &mut Out, t: &Transition) {
         601..=900 => "med",
         _ => "slow",
     };
-    let sound = t.sound.and_then(|m| x.media_rel(o, m, "audio").map(|r| (r, x.p.media(m).map(|i| i.name.clone()).unwrap_or_default())));
+    let sound = t.sound.and_then(|m| x.media_rel(o, m, "audio").map(|r| (r, x.media(m).map(|i| i.name.clone()).unwrap_or_default())));
     let snd = |w: &mut W| {
         if let Some((r, name)) = &sound {
             w.open0("p:sndAc");

crates/pptx/tests/it/export_scale.rs

@@ -0,0 +1,31 @@
+//! Export looks media, layouts, sections and table styles up by id: a deck with many of each and
+//! many references to the last ones exports in time linear in its size.
+
+use std::sync::Arc;
+
+use deckcraft_model::style::PictureFill;
+use deckcraft_model::{Section, Shape, ShapeId, ShapeKind, defaults};
+
+#[test]
+fn many_media_sections_and_table_styles_export() {
+    let mut p = defaults::new_presentation(None);
+    // 5,000 media items; 5,000 pictures of the last one.
+    let mut last = None;
+    for i in 0..5_000u32 {
+        last = p.add_media(&format!("m{i}.png"), "image/png", i.to_le_bytes().to_vec());
+    }
+    let last = last.unwrap();
+    let pic = |k: u32| Shape {
+        id: ShapeId(100_000 + k),
+        kind: ShapeKind::Picture { fill: PictureFill { media: last, ..Default::default() } },
+        ..Default::default()
+    };
+    Arc::make_mut(&mut p.slides[0]).shapes = (0..5_000).map(pic).collect();
+    // A section naming the slide 50,000 times, after 2,000 empty sections.
+    let id = p.slides[0].id;
+    p.sections = (0..2_000).map(|i| Section { name: format!("s{i}"), slides: vec![] }).collect();
+    p.sections.push(Section { name: "last".into(), slides: vec![id; 50_000] });
+    let bytes = deckcraft_pptx::export(&p).expect("export");
+    let q = deckcraft_pptx::import(&bytes).expect("import");
+    assert_eq!(q.slides[0].shapes.iter().filter(|s| matches!(s.kind, ShapeKind::Picture { .. })).count(), 5_000);
+}

crates/pptx/tests/it/main.rs

@@ -9,6 +9,7 @@ mod corpus_kinds;
 mod corpus_media;
 mod corpus_style;
 mod corpus_themes;
+mod export_scale;
 mod fills;
 mod kept_parts;
 mod locks;

xtask/src/stats.rs

@@ -18,13 +18,7 @@ fn walk(dir: &Path, c: &mut Counts) {
         let p = e.path();
         let name = e.file_name();
         let name = name.to_string_lossy();
-        // `file_type` does not follow links, so a directory link is not walked (and aliases are
-        // not counted twice).
-        let Ok(kind) = e.file_type() else { continue };
-        if kind.is_symlink() {
-            continue;
-        }
-        if kind.is_dir() {
+        if p.is_dir() {
             // Nested fuzz workspaces and build output are not part of the crate.
             if name != "target" && name != "fuzz" && !name.starts_with('.') {
                 walk(&p, c);