refactoring

gpx-rs/engine/src/core/gpx/chunk.rs

@@ -2,6 +2,29 @@ use uuid::Uuid;
 
 use crate::{Trackpoint, Waypoint};
 
+/// A run of items, shared between the successive versions of a [`crate::Chunked`] list: a chunk
+/// that is not touched by an edit is not copied.
+///
+/// Chunks are equal when they have the same identity, which is cheap to compare and changes
+/// whenever the content does (a modified chunk is a new one).
+pub trait Chunk {
+    type Item: Clone;
+
+    /// Maximum number of items of a chunk.
+    const MAX_SIZE: usize;
+
+    /// A chunk with a new identity, holding `items`.
+    fn new(items: Vec<Self::Item>) -> Self;
+
+    fn items(&self) -> &Vec<Self::Item>;
+
+    fn items_mut(&mut self) -> &mut Vec<Self::Item>;
+
+    fn is_full(&self) -> bool {
+        self.items().len() >= Self::MAX_SIZE
+    }
+}
+
 const MAX_TRKPT_CHUNK_SIZE: usize = 4096;
 
 #[derive(Debug, PartialEq, Eq)]
@@ -25,9 +48,23 @@ impl PartialEq for TrackpointChunk {
     }
 }
 
-impl TrackpointChunk {
-    pub fn is_full(&self) -> bool {
-        self.trkpt.len() == MAX_TRKPT_CHUNK_SIZE
+impl Chunk for TrackpointChunk {
+    type Item = Trackpoint;
+    const MAX_SIZE: usize = MAX_TRKPT_CHUNK_SIZE;
+
+    fn new(trkpt: Vec<Trackpoint>) -> Self {
+        Self {
+            trkpt,
+            ..Default::default()
+        }
+    }
+
+    fn items(&self) -> &Vec<Trackpoint> {
+        &self.trkpt
+    }
+
+    fn items_mut(&mut self) -> &mut Vec<Trackpoint> {
+        &mut self.trkpt
     }
 }
 
@@ -54,9 +91,23 @@ impl PartialEq for WaypointChunk {
     }
 }
 
-impl WaypointChunk {
-    pub fn is_full(&self) -> bool {
-        self.wpt.len() == MAX_WPT_CHUNK_SIZE
+impl Chunk for WaypointChunk {
+    type Item = Waypoint;
+    const MAX_SIZE: usize = MAX_WPT_CHUNK_SIZE;
+
+    fn new(wpt: Vec<Waypoint>) -> Self {
+        Self {
+            wpt,
+            ..Default::default()
+        }
+    }
+
+    fn items(&self) -> &Vec<Waypoint> {
+        &self.wpt
+    }
+
+    fn items_mut(&mut self) -> &mut Vec<Waypoint> {
+        &mut self.wpt
     }
 }
 
@@ -86,6 +137,15 @@ mod tests {
         assert!(chunk.is_full());
     }
 
+    #[test]
+    fn test_new_chunks_have_their_own_identity() {
+        let a = TrackpointChunk::new(vec![Trackpoint::default()]);
+        let b = TrackpointChunk::new(vec![Trackpoint::default()]);
+        assert_ne!(a, b);
+        assert_eq!(a.items().len(), 1);
+        assert_ne!(WaypointChunk::new(vec![]), WaypointChunk::new(vec![]));
+    }
+
     #[test]
     fn test_chunk_equality_is_by_id() {
         let a = TrackpointChunk::default();

gpx-rs/engine/src/core/gpx/chunked.rs

@@ -0,0 +1,328 @@
+use std::{ops::Index, rc::Rc};
+
+use crate::Chunk;
+
+/// A list of items, stored in [`Chunk`]s that are shared between its versions: editing it only
+/// copies the chunks around the change, so that a version costs little more than the change.
+///
+/// There are no empty chunks.
+#[derive(Debug, PartialEq)]
+pub struct Chunked<C: Chunk> {
+    chunks: Vec<Rc<C>>,
+    cumul_length: Vec<usize>,
+}
+
+impl<C: Chunk> Clone for Chunked<C> {
+    fn clone(&self) -> Self {
+        Self {
+            chunks: self.chunks.clone(),
+            cumul_length: self.cumul_length.clone(),
+        }
+    }
+}
+
+impl<C: Chunk> Default for Chunked<C> {
+    fn default() -> Self {
+        Self {
+            chunks: vec![],
+            cumul_length: vec![],
+        }
+    }
+}
+
+/// The position of an item: in which chunk, where in it, and among all the items.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default, PartialOrd, Ord)]
+pub struct ChunkIndex {
+    pub chunk: usize,
+    pub pos: usize,
+    pub flat: usize,
+}
+
+impl<C: Chunk> Chunked<C> {
+    /// Adds a chunk at the end, which is dropped if it is empty.
+    pub fn push(&mut self, chunk: C) {
+        self.push_shared(Rc::new(chunk));
+    }
+
+    pub fn push_shared(&mut self, chunk: Rc<C>) {
+        if chunk.items().is_empty() {
+            return;
+        }
+        self.cumul_length
+            .push(self.cumul_length.last().copied().unwrap_or_default() + chunk.items().len());
+        self.chunks.push(chunk);
+    }
+
+    pub fn chunks(&self) -> &[Rc<C>] {
+        &self.chunks
+    }
+
+    /// Replaces the items in `start..end` by `items`. Panics if the range is out of bounds.
+    ///
+    /// Chunks that are not concerned are kept as they are (shared), only the chunks around the
+    /// range are copied and refilled.
+    pub fn splice(&mut self, start: usize, end: usize, items: Vec<C::Item>) {
+        assert!(
+            start <= end && end <= self.len(),
+            "splice range out of bounds"
+        );
+        let old = std::mem::take(&mut self.chunks);
+        self.cumul_length.clear();
+
+        let mut items = Some(items);
+        let mut pending = vec![];
+        let mut offset = 0;
+        for chunk in old {
+            let (lo, hi) = (offset, offset + chunk.items().len());
+            offset = hi;
+            // a chunk ending at `start` is extended unless it is full, to avoid tiny chunks
+            if hi < start || (hi == start && chunk.is_full()) {
+                self.push_shared(chunk);
+                continue;
+            }
+            if let Some(items) = items.take() {
+                self.fill(&mut pending, chunk.items()[..start - lo].iter().cloned());
+                self.fill(&mut pending, items);
+            }
+            if hi <= end {
+                continue;
+            }
+            if lo >= end {
+                self.flush(&mut pending);
+                self.push_shared(chunk);
+            } else {
+                self.fill(&mut pending, chunk.items()[end - lo..].iter().cloned());
+            }
+        }
+        if let Some(items) = items {
+            self.fill(&mut pending, items);
+        }
+        self.flush(&mut pending);
+    }
+
+    fn fill(&mut self, pending: &mut Vec<C::Item>, items: impl IntoIterator<Item = C::Item>) {
+        for item in items {
+            pending.push(item);
+            if pending.len() >= C::MAX_SIZE {
+                self.flush(pending);
+            }
+        }
+    }
+
+    fn flush(&mut self, pending: &mut Vec<C::Item>) {
+        self.push(C::new(std::mem::take(pending)));
+    }
+
+    /// Edits the items of the chunks that contain an item accepted by `filter`.
+    ///
+    /// `f` receives a copy of the items of such a chunk and returns whether it changed them. A
+    /// changed chunk is replaced by a new one (so that what is derived from it is computed
+    /// again) and the chunks left empty are dropped. The other chunks are kept. Returns whether
+    /// anything changed.
+    pub fn edit(
+        &mut self,
+        filter: impl Fn(&C::Item) -> bool,
+        mut f: impl FnMut(&mut Vec<C::Item>) -> bool,
+    ) -> bool {
+        let mut changed = false;
+        let old = std::mem::take(&mut self.chunks);
+        self.cumul_length.clear();
+        for chunk in old {
+            if !chunk.items().iter().any(&filter) {
+                self.push_shared(chunk);
+                continue;
+            }
+            let mut items = chunk.items().clone();
+            if !f(&mut items) {
+                self.push_shared(chunk);
+                continue;
+            }
+            changed = true;
+            self.push(C::new(items));
+        }
+        changed
+    }
+
+    /// Changes what is in the chunk `chunk`, but not how many items there are. A chunk that is
+    /// shared is copied first, so that the other versions do not change.
+    fn replace_chunk(&mut self, chunk: usize, f: impl FnOnce(&mut Vec<C::Item>)) {
+        let len = self.chunks[chunk].items().len();
+        match Rc::get_mut(&mut self.chunks[chunk]) {
+            Some(unique) => f(unique.items_mut()),
+            None => {
+                let mut items = self.chunks[chunk].items().clone();
+                f(&mut items);
+                self.chunks[chunk] = Rc::new(C::new(items));
+            }
+        }
+        debug_assert_eq!(self.chunks[chunk].items().len(), len);
+    }
+
+    /// Applies `f` to the item at `index`, which is copied in a new chunk. Panics if there is no
+    /// such item.
+    pub fn update(&mut self, index: usize, f: impl FnOnce(&mut C::Item)) {
+        let ChunkIndex { chunk, pos, .. } = self.locate(index).unwrap();
+        self.replace_chunk(chunk, |items| f(&mut items[pos]));
+    }
+
+    /// Applies `f` to every item, with its index, in new chunks.
+    pub fn update_all(&mut self, mut f: impl FnMut(usize, &mut C::Item)) {
+        let mut offset = 0;
+        for chunk in 0..self.chunks.len() {
+            let len = self.chunks[chunk].items().len();
+            self.replace_chunk(chunk, |items| {
+                for (i, item) in items.iter_mut().enumerate() {
+                    f(offset + i, item);
+                }
+            });
+            offset += len;
+        }
+    }
+
+    pub fn len(&self) -> usize {
+        self.cumul_length.last().copied().unwrap_or_default()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.chunks.is_empty()
+    }
+
+    pub fn iter(&self) -> ChunkedIter<'_, C> {
+        ChunkedIter::new(self)
+    }
+
+    pub fn first_index(&self) -> Option<ChunkIndex> {
+        self.next_index(None)
+    }
+
+    pub fn last_index(&self) -> Option<ChunkIndex> {
+        self.prev_index(None)
+    }
+
+    pub fn next_index(&self, cur: Option<ChunkIndex>) -> Option<ChunkIndex> {
+        let mut next = cur.map_or_default(|idx| ChunkIndex {
+            chunk: idx.chunk,
+            pos: idx.pos + 1,
+            flat: idx.flat + 1,
+        });
+        loop {
+            if next.chunk >= self.chunks.len() {
+                return None;
+            }
+            if next.pos == self.chunks[next.chunk].items().len() {
+                next.chunk += 1;
+                next.pos = 0;
+            } else {
+                return Some(next);
+            }
+        }
+    }
+
+    pub fn prev_index(&self, cur: Option<ChunkIndex>) -> Option<ChunkIndex> {
+        let mut prev = cur.unwrap_or(ChunkIndex {
+            chunk: self.chunks.len(),
+            pos: 0,
+            flat: self.cumul_length.last().copied().unwrap_or_default(),
+        });
+        if prev.pos == 0 {
+            while prev.chunk > 0 {
+                prev.chunk -= 1;
+                if !self.chunks[prev.chunk].items().is_empty() {
+                    prev.pos = self.chunks[prev.chunk].items().len() - 1;
+                    prev.flat -= 1;
+                    return Some(prev);
+                }
+            }
+            None
+        } else {
+            prev.pos -= 1;
+            prev.flat -= 1;
+            Some(prev)
+        }
+    }
+
+    /// The position of the item `idx` among all the items.
+    pub fn locate(&self, idx: usize) -> Option<ChunkIndex> {
+        let chunk = self.cumul_length.partition_point(|l| idx >= *l);
+        if chunk >= self.chunks.len() {
+            return None;
+        }
+        let pos = if chunk > 0 {
+            idx - self.cumul_length[chunk - 1]
+        } else {
+            idx
+        };
+        if pos >= self.chunks[chunk].items().len() {
+            None
+        } else {
+            Some(ChunkIndex {
+                chunk,
+                pos,
+                flat: idx,
+            })
+        }
+    }
+}
+
+impl<C: Chunk> Index<ChunkIndex> for Chunked<C> {
+    type Output = C::Item;
+
+    fn index(&self, idx: ChunkIndex) -> &Self::Output {
+        &self.chunks[idx.chunk].items()[idx.pos]
+    }
+}
+
+impl<C: Chunk> Index<usize> for Chunked<C> {
+    type Output = C::Item;
+
+    fn index(&self, idx: usize) -> &Self::Output {
+        &self[self.locate(idx).unwrap()]
+    }
+}
+
+impl<'a, C: Chunk> IntoIterator for &'a Chunked<C> {
+    type Item = &'a C::Item;
+    type IntoIter = ChunkedIter<'a, C>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
+
+pub struct ChunkedIter<'a, C: Chunk> {
+    chunked: &'a Chunked<C>,
+    idx: Option<ChunkIndex>,
+}
+
+impl<C: Chunk> Clone for ChunkedIter<'_, C> {
+    fn clone(&self) -> Self {
+        Self {
+            chunked: self.chunked,
+            idx: self.idx,
+        }
+    }
+}
+
+impl<'a, C: Chunk> ChunkedIter<'a, C> {
+    pub fn new(chunked: &'a Chunked<C>) -> Self {
+        Self {
+            chunked,
+            idx: Default::default(),
+        }
+    }
+}
+
+impl<'a, C: Chunk> Iterator for ChunkedIter<'a, C> {
+    type Item = &'a C::Item;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.idx = self.chunked.next_index(self.idx);
+        self.idx.map(|idx| &self.chunked[idx])
+    }
+
+    fn nth(&mut self, n: usize) -> Option<Self::Item> {
+        let idx = self.idx.map_or_default(|idx| idx.flat) + n;
+        self.idx = self.chunked.locate(idx);
+        self.idx.map(|idx| &self.chunked[idx])
+    }
+}

gpx-rs/engine/src/core/gpx/file.rs

@@ -1,8 +1,6 @@
-use std::rc::Rc;
-
 use uuid::Uuid;
 
-use crate::{Link, Track, WaypointChunk};
+use crate::{Link, Track, Waypoints};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct FileId(pub Uuid);
@@ -13,22 +11,12 @@ impl Default for FileId {
     }
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct FileWaypointsRevisionId(pub Uuid);
-
-impl Default for FileWaypointsRevisionId {
-    fn default() -> Self {
-        Self(Uuid::new_v4())
-    }
-}
-
 #[derive(Debug, Default, Clone, PartialEq)]
 pub struct File {
     pub id: FileId,
     pub info: FileInfo,
     pub trk: Vec<Track>,
-    pub wpt: Vec<Rc<WaypointChunk>>,
-    pub wpt_rev_id: FileWaypointsRevisionId,
+    pub wpt: Waypoints,
     // TODO routes
 }
 

gpx-rs/engine/src/core/gpx/mod.rs

@@ -1,17 +1,21 @@
 mod categories;
 mod chunk;
+mod chunked;
 mod common;
 mod file;
 mod segment;
 mod track;
 mod trackpoint;
 mod waypoint;
+mod waypoints;
 
 pub use categories::*;
 pub use chunk::*;
+pub use chunked::*;
 pub use common::*;
 pub use file::*;
 pub use segment::*;
 pub use track::*;
 pub use trackpoint::*;
 pub use waypoint::*;
+pub use waypoints::*;

gpx-rs/engine/src/core/gpx/segment.rs

@@ -1,8 +1,8 @@
-use std::{ops::Index, rc::Rc};
+use std::ops::{Deref, DerefMut};
 
 use uuid::Uuid;
 
-use crate::{Trackpoint, TrackpointChunk, compute_anchors};
+use crate::{ChunkIndex, Chunked, ChunkedIter, Trackpoint, TrackpointChunk, compute_anchors};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct TrackSegmentId(pub Uuid);
@@ -26,66 +26,33 @@ impl Default for TrackSegmentRevisionId {
 pub struct TrackSegment {
     pub id: TrackSegmentId,
     pub rev_id: TrackSegmentRevisionId,
-    chunks: Vec<Rc<TrackpointChunk>>,
-    cumul_length: Vec<usize>,
+    points: Chunked<TrackpointChunk>,
+}
+
+/// The position of a trackpoint in a segment.
+pub type TrackSegmentIndex = ChunkIndex;
+
+pub type TrackSegmentIterator<'a> = ChunkedIter<'a, TrackpointChunk>;
+
+impl Deref for TrackSegment {
+    type Target = Chunked<TrackpointChunk>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.points
+    }
+}
+
+impl DerefMut for TrackSegment {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.points
+    }
 }
 
 impl TrackSegment {
-    pub fn push(&mut self, chunk: TrackpointChunk) {
-        self.push_shared(Rc::new(chunk));
-    }
-
-    fn push_shared(&mut self, chunk: Rc<TrackpointChunk>) {
-        if chunk.trkpt.is_empty() {
-            return;
-        }
-        self.cumul_length
-            .push(self.cumul_length.last().copied().unwrap_or_default() + chunk.trkpt.len());
-        self.chunks.push(chunk);
-    }
-
-    /// Replaces the points in `start..end` by `points`. Panics if the range is out of bounds.
-    ///
-    /// Chunks that are not concerned are kept as they are (shared), only the chunks around the
-    /// range are copied and refilled.
+    /// Replaces the points in `start..end` by `points`, see [`Chunked::splice`]. The first and
+    /// last trackpoints are anchors afterwards.
     pub fn splice(&mut self, start: usize, end: usize, points: Vec<Trackpoint>) {
-        assert!(
-            start <= end && end <= self.len(),
-            "splice range out of bounds"
-        );
-        let old = std::mem::take(&mut self.chunks);
-        self.cumul_length.clear();
-
-        let mut pending = TrackpointChunk::default();
-        let mut inserted = false;
-        let mut offset = 0;
-        for chunk in old {
-            let (lo, hi) = (offset, offset + chunk.trkpt.len());
-            offset = hi;
-            // a chunk ending at `start` is extended unless it is full, to avoid tiny chunks
-            if hi < start || (hi == start && chunk.is_full()) {
-                self.push_shared(chunk);
-                continue;
-            }
-            if !inserted {
-                self.fill(&mut pending, chunk.trkpt[..start - lo].iter().cloned());
-                self.fill(&mut pending, points.iter().cloned());
-                inserted = true;
-            }
-            if hi <= end {
-                continue;
-            }
-            if lo >= end {
-                self.flush(&mut pending);
-                self.push_shared(chunk);
-            } else {
-                self.fill(&mut pending, chunk.trkpt[end - lo..].iter().cloned());
-            }
-        }
-        if !inserted {
-            self.fill(&mut pending, points);
-        }
-        self.flush(&mut pending);
+        self.points.splice(start, end, points);
         self.ensure_end_anchors();
     }
 
@@ -99,7 +66,7 @@ impl TrackSegment {
         };
         for index in [0, last] {
             if self[index].anchor != Some(0) {
-                self.point_mut(index).anchor = Some(0);
+                self.set_anchor(index, 0);
             }
         }
     }
@@ -107,7 +74,7 @@ impl TrackSegment {
     /// Makes the trackpoint at `index` an anchor shown from the map zoom level `zoom`. Panics if
     /// there is no such trackpoint.
     pub fn set_anchor(&mut self, index: usize, zoom: u8) {
-        self.point_mut(index).anchor = Some(zoom);
+        self.points.update(index, |trkpt| trkpt.anchor = Some(zoom));
     }
 
     /// Sets the anchors of the trackpoints from the details of the path of the segment (see
@@ -115,7 +82,7 @@ impl TrackSegment {
     pub fn compute_anchors(&mut self) {
         let anchors = compute_anchors(self);
         let mut anchors = anchors.into_iter().peekable();
-        self.map_points(|index, trkpt| {
+        self.points.update_all(|index, trkpt| {
             trkpt.anchor = match anchors.peek() {
                 Some(&(anchor, zoom)) if anchor == index => {
                     anchors.next();
@@ -125,191 +92,12 @@ impl TrackSegment {
             };
         });
     }
-
-    /// A chunk that can be modified: the shared chunks are copied first.
-    fn chunk_mut(&mut self, chunk: usize) -> &mut TrackpointChunk {
-        let shared = &mut self.chunks[chunk];
-        if Rc::get_mut(shared).is_none() {
-            *shared = Rc::new(TrackpointChunk {
-                trkpt: shared.trkpt.clone(),
-                ..Default::default()
-            });
-        }
-        Rc::get_mut(shared).unwrap()
-    }
-
-    fn point_mut(&mut self, index: usize) -> &mut Trackpoint {
-        let TrackSegmentIndex { chunk, pos, .. } = self.locate(index).unwrap();
-        &mut self.chunk_mut(chunk).trkpt[pos]
-    }
-
-    /// Applies `f` to every trackpoint, with its index in the segment.
-    fn map_points(&mut self, mut f: impl FnMut(usize, &mut Trackpoint)) {
-        let mut offset = 0;
-        for chunk in 0..self.chunks.len() {
-            for (i, trkpt) in self.chunk_mut(chunk).trkpt.iter_mut().enumerate() {
-                f(offset + i, trkpt);
-            }
-            offset += self.chunks[chunk].trkpt.len();
-        }
-    }
-
-    fn fill(
-        &mut self,
-        pending: &mut TrackpointChunk,
-        points: impl IntoIterator<Item = Trackpoint>,
-    ) {
-        for trkpt in points {
-            pending.trkpt.push(trkpt);
-            if pending.is_full() {
-                self.flush(pending);
-            }
-        }
-    }
-
-    fn flush(&mut self, pending: &mut TrackpointChunk) {
-        self.push(std::mem::take(pending));
-    }
-
-    pub fn len(&self) -> usize {
-        self.cumul_length.last().copied().unwrap_or_default()
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.chunks.is_empty()
-    }
-
-    pub fn iter(&self) -> TrackSegmentIterator<'_> {
-        TrackSegmentIterator::new(self)
-    }
-
-    pub fn first_index(&self) -> Option<TrackSegmentIndex> {
-        self.next_index(None)
-    }
-
-    pub fn last_index(&self) -> Option<TrackSegmentIndex> {
-        self.prev_index(None)
-    }
-
-    pub fn next_index(&self, cur: Option<TrackSegmentIndex>) -> Option<TrackSegmentIndex> {
-        let mut next = cur.map_or_default(|idx| TrackSegmentIndex {
-            chunk: idx.chunk,
-            pos: idx.pos + 1,
-            flat: idx.flat + 1,
-        });
-        loop {
-            if next.chunk >= self.chunks.len() {
-                return None;
-            }
-            if next.pos == self.chunks[next.chunk].trkpt.len() {
-                next.chunk += 1;
-                next.pos = 0;
-            } else {
-                return Some(next);
-            }
-        }
-    }
-
-    pub fn prev_index(&self, cur: Option<TrackSegmentIndex>) -> Option<TrackSegmentIndex> {
-        let mut prev = cur.unwrap_or(TrackSegmentIndex {
-            chunk: self.chunks.len(),
-            pos: 0,
-            flat: self.cumul_length.last().copied().unwrap_or_default(),
-        });
-        if prev.pos == 0 {
-            while prev.chunk > 0 {
-                prev.chunk -= 1;
-                if !self.chunks[prev.chunk].trkpt.is_empty() {
-                    prev.pos = self.chunks[prev.chunk].trkpt.len() - 1;
-                    prev.flat -= 1;
-                    return Some(prev);
-                }
-            }
-            None
-        } else {
-            prev.pos -= 1;
-            prev.flat -= 1;
-            Some(prev)
-        }
-    }
-
-    fn locate(&self, idx: usize) -> Option<TrackSegmentIndex> {
-        let chunk = self.cumul_length.partition_point(|l| idx >= *l);
-        if chunk >= self.chunks.len() {
-            return None;
-        }
-        let pos = if chunk > 0 {
-            idx - self.cumul_length[chunk - 1]
-        } else {
-            idx
-        };
-        if pos >= self.chunks[chunk].trkpt.len() {
-            None
-        } else {
-            Some(TrackSegmentIndex {
-                chunk,
-                pos,
-                flat: idx,
-            })
-        }
-    }
-}
-
-impl Index<TrackSegmentIndex> for TrackSegment {
-    type Output = Trackpoint;
-
-    fn index(&self, idx: TrackSegmentIndex) -> &Self::Output {
-        &self.chunks[idx.chunk].trkpt[idx.pos]
-    }
-}
-
-impl Index<usize> for TrackSegment {
-    type Output = Trackpoint;
-
-    fn index(&self, idx: usize) -> &Self::Output {
-        &self[self.locate(idx).unwrap()]
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Default, PartialOrd, Ord)]
-pub struct TrackSegmentIndex {
-    pub chunk: usize,
-    pub pos: usize,
-    pub flat: usize,
-}
-
-#[derive(Debug, Clone)]
-pub struct TrackSegmentIterator<'a> {
-    trkseg: &'a TrackSegment,
-    idx: Option<TrackSegmentIndex>,
-}
-
-impl<'a> TrackSegmentIterator<'a> {
-    pub fn new(trkseg: &'a TrackSegment) -> Self {
-        Self {
-            trkseg,
-            idx: Default::default(),
-        }
-    }
-}
-
-impl<'a> Iterator for TrackSegmentIterator<'a> {
-    type Item = &'a Trackpoint;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        self.idx = self.trkseg.next_index(self.idx);
-        self.idx.map(|idx| &self.trkseg[idx])
-    }
-
-    fn nth(&mut self, n: usize) -> Option<Self::Item> {
-        let idx = self.idx.map_or_default(|idx| idx.flat) + n;
-        self.idx = self.trkseg.locate(idx);
-        self.idx.map(|idx| &self.trkseg[idx])
-    }
 }
 
 #[cfg(test)]
 mod tests {
+    use std::rc::Rc;
+
     use super::*;
 
     fn create_track_segment(nb_chunks: usize) -> TrackSegment {
@@ -427,14 +215,14 @@ mod tests {
         let mut trkseg = create_track_segment(5);
         // the ends are anchors already, or their chunks would be copied
         trkseg.ensure_end_anchors();
-        let before = trkseg.chunks.clone();
+        let before = trkseg.chunks().to_vec();
         // inside the third chunk only
         trkseg.splice(4, 5, points(&[-1.0]));
-        assert!(Rc::ptr_eq(&trkseg.chunks[0], &before[0]));
-        assert!(Rc::ptr_eq(&trkseg.chunks[1], &before[1]));
-        assert!(Rc::ptr_eq(trkseg.chunks.last().unwrap(), &before[4]));
+        assert!(Rc::ptr_eq(&trkseg.chunks()[0], &before[0]));
+        assert!(Rc::ptr_eq(&trkseg.chunks()[1], &before[1]));
+        assert!(Rc::ptr_eq(trkseg.chunks().last().unwrap(), &before[4]));
         assert!(Rc::ptr_eq(
-            &trkseg.chunks[trkseg.chunks.len() - 2],
+            &trkseg.chunks()[trkseg.chunks().len() - 2],
             &before[3]
         ));
     }
@@ -447,10 +235,10 @@ mod tests {
             trkseg.splice(len, len, points(&[i as f64]));
         }
         assert_eq!(trkseg.len(), 10_000);
-        assert!(trkseg.chunks.len() <= 3);
-        assert!(trkseg.chunks.iter().all(|c| c.trkpt.len() <= 4096));
+        assert!(trkseg.chunks().len() <= 3);
+        assert!(trkseg.chunks().iter().all(|c| c.trkpt.len() <= 4096));
         assert_eq!(trkseg[9_999].ele, 9_999.0);
-        assert_eq!(*trkseg.cumul_length.last().unwrap(), 10_000);
+        assert_eq!(trkseg.len(), 10_000);
     }
 
     #[test]
@@ -496,7 +284,7 @@ mod tests {
         let nb_chunks = 10;
         let trkseg = create_track_segment(nb_chunks);
         let _ = trkseg[TrackSegmentIndex {
-            chunk: trkseg.chunks.len(),
+            chunk: trkseg.chunks().len(),
             pos: 0,
             flat: 0,
         }];

gpx-rs/engine/src/core/gpx/waypoints.rs

@@ -0,0 +1,316 @@
+use std::ops::Deref;
+
+use uuid::Uuid;
+
+use crate::{Chunked, Waypoint, WaypointChunk, WaypointId};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct FileWaypointsRevisionId(pub Uuid);
+
+impl Default for FileWaypointsRevisionId {
+    fn default() -> Self {
+        Self(Uuid::new_v4())
+    }
+}
+
+/// The waypoints of a file, in chunks that are shared between the versions of the file (see
+/// [`Chunked`]).
+///
+/// Everything that changes the waypoints changes the revision too, which is why there is no
+/// mutable access to the list itself: the revision tells what is derived from the waypoints
+/// (coordinates for the map...) that it is out of date.
+#[derive(Debug, Default, Clone, PartialEq)]
+pub struct Waypoints {
+    chunks: Chunked<WaypointChunk>,
+    /// Changes when the waypoints do.
+    pub rev_id: FileWaypointsRevisionId,
+}
+
+impl Deref for Waypoints {
+    type Target = Chunked<WaypointChunk>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.chunks
+    }
+}
+
+impl Waypoints {
+    /// Waypoints made of the given chunks, which are used as they are.
+    pub fn new(chunks: impl IntoIterator<Item = WaypointChunk>) -> Self {
+        let mut waypoints = Self::default();
+        for chunk in chunks {
+            waypoints.push(chunk);
+        }
+        waypoints
+    }
+
+    /// Adds a chunk after the last waypoint.
+    pub fn push(&mut self, chunk: WaypointChunk) {
+        self.chunks.push(chunk);
+        self.rev_id = Default::default();
+    }
+
+    /// Replaces the waypoints in `start..end` by `waypoints`, see [`Chunked::splice`].
+    pub fn splice(&mut self, start: usize, end: usize, waypoints: Vec<Waypoint>) {
+        self.chunks.splice(start, end, waypoints);
+        self.rev_id = Default::default();
+    }
+
+    /// Inserts waypoints, so that the first one is at `index` among the waypoints (at the end if
+    /// the index is past it). Only the chunks around the insertion are copied.
+    pub fn insert_at(&mut self, index: usize, waypoints: Vec<Waypoint>) {
+        if waypoints.is_empty() {
+            return;
+        }
+        let index = index.min(self.len());
+        self.splice(index, index, waypoints);
+    }
+
+    /// Inserts waypoints right after the waypoint `after`, or at the end if there is none (or if
+    /// it is not there). See [`Waypoints::insert_at`].
+    pub fn insert_after(&mut self, after: Option<WaypointId>, waypoints: Vec<Waypoint>) {
+        let index = after
+            .and_then(|after| self.position(after))
+            .map_or(usize::MAX, |i| i + 1);
+        self.insert_at(index, waypoints);
+    }
+
+    /// The position of the waypoint among the waypoints.
+    pub fn position(&self, id: WaypointId) -> Option<usize> {
+        self.iter().position(|wpt| wpt.id == id)
+    }
+
+    /// Edits the waypoints of the chunks that contain one accepted by `filter`, see
+    /// [`Chunked::edit`]. Returns whether anything changed.
+    pub fn edit(
+        &mut self,
+        filter: impl Fn(&Waypoint) -> bool,
+        f: impl FnMut(&mut Vec<Waypoint>) -> bool,
+    ) -> bool {
+        let changed = self.chunks.edit(filter, f);
+        if changed {
+            self.rev_id = Default::default();
+        }
+        changed
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::rc::Rc;
+
+    use super::*;
+
+    fn waypoint() -> Waypoint {
+        Waypoint::default()
+    }
+
+    fn waypoints_with(chunks: &[usize]) -> (Waypoints, Vec<WaypointId>) {
+        let mut waypoints = Waypoints::default();
+        let mut ids = vec![];
+        for n in chunks {
+            let wpt: Vec<_> = (0..*n).map(|_| waypoint()).collect();
+            ids.extend(wpt.iter().map(|w| w.id));
+            waypoints.push(WaypointChunk {
+                wpt,
+                ..Default::default()
+            });
+        }
+        (waypoints, ids)
+    }
+
+    fn ids(waypoints: &Waypoints) -> Vec<WaypointId> {
+        waypoints.iter().map(|w| w.id).collect()
+    }
+
+    #[test]
+    fn test_new_and_push() {
+        let (waypoints, ids_) = waypoints_with(&[2, 1]);
+        assert_eq!(waypoints.len(), 3);
+        assert_eq!(waypoints.chunks().len(), 2);
+        assert_eq!(ids(&waypoints), ids_);
+        assert_eq!(waypoints.position(ids_[2]), Some(2));
+        assert_eq!(waypoints.position(WaypointId::default()), None);
+        // empty chunks are dropped
+        let waypoints = Waypoints::new([WaypointChunk::default()]);
+        assert!(waypoints.is_empty());
+    }
+
+    #[test]
+    fn test_insert_at_the_end() {
+        let (mut waypoints, before) = waypoints_with(&[2, 1]);
+        let first = waypoints.chunks()[0].clone();
+        let rev = waypoints.rev_id;
+        let new = vec![waypoint(), waypoint()];
+        let new_ids: Vec<_> = new.iter().map(|w| w.id).collect();
+        waypoints.insert_after(None, new);
+        assert_eq!(ids(&waypoints), [before.clone(), new_ids].concat());
+        // the chunk that is not touched is kept, the last one is extended
+        assert_eq!(waypoints.chunks().len(), 2);
+        assert!(Rc::ptr_eq(&waypoints.chunks()[0], &first));
+        assert_ne!(waypoints.rev_id, rev);
+        // an unknown waypoint is an insertion at the end too
+        let (mut waypoints, before) = waypoints_with(&[2]);
+        let one = waypoint();
+        let one_id = one.id;
+        waypoints.insert_after(Some(WaypointId::default()), vec![one]);
+        assert_eq!(ids(&waypoints), [before, vec![one_id]].concat());
+    }
+
+    #[test]
+    fn test_insert_after_the_last_waypoint_of_a_chunk_keeps_the_next_ones() {
+        let (mut waypoints, before) = waypoints_with(&[2, 2]);
+        let last = waypoints.chunks()[1].clone();
+        let one = waypoint();
+        let one_id = one.id;
+        waypoints.insert_after(Some(before[1]), vec![one]);
+        assert_eq!(
+            ids(&waypoints),
+            [&before[..2], &[one_id], &before[2..]].concat()
+        );
+        assert_eq!(waypoints.chunks().len(), 2);
+        assert!(Rc::ptr_eq(&waypoints.chunks()[1], &last));
+    }
+
+    #[test]
+    fn test_insert_in_the_middle_of_a_chunk_cuts_it() {
+        let (mut waypoints, before) = waypoints_with(&[3, 1]);
+        let last = waypoints.chunks()[1].clone();
+        let new = vec![waypoint(), waypoint()];
+        let new_ids: Vec<_> = new.iter().map(|w| w.id).collect();
+        waypoints.insert_after(Some(before[0]), new);
+        assert_eq!(
+            ids(&waypoints),
+            [&before[..1], &new_ids[..], &before[1..]].concat()
+        );
+        // the cut chunk is refilled, the other one is kept
+        assert_eq!(waypoints.chunks().len(), 2);
+        assert!(Rc::ptr_eq(&waypoints.chunks()[1], &last));
+    }
+
+    #[test]
+    fn test_insert_nothing() {
+        let (mut waypoints, before) = waypoints_with(&[2]);
+        let rev = waypoints.rev_id;
+        waypoints.insert_after(Some(before[0]), vec![]);
+        assert_eq!(ids(&waypoints), before);
+        assert_eq!(waypoints.rev_id, rev);
+    }
+
+    #[test]
+    fn test_insert_many_fills_chunks() {
+        let mut waypoints = Waypoints::default();
+        let new: Vec<_> = (0..300).map(|_| waypoint()).collect();
+        let new_ids: Vec<_> = new.iter().map(|w| w.id).collect();
+        waypoints.insert_after(None, new);
+        assert_eq!(ids(&waypoints), new_ids);
+        assert_eq!(waypoints.chunks().len(), 3);
+        assert!(waypoints.chunks()[..2].iter().all(|chunk| {
+            use crate::Chunk;
+            chunk.is_full()
+        }));
+    }
+
+    #[test]
+    fn test_insert_at_an_index() {
+        // at the start
+        let (mut waypoints, before) = waypoints_with(&[2, 1]);
+        let first = waypoints.chunks()[0].clone();
+        let one = waypoint();
+        let one_id = one.id;
+        waypoints.insert_at(0, vec![one]);
+        assert_eq!(ids(&waypoints), [vec![one_id], before.clone()].concat());
+        // the existing chunks are kept
+        assert_eq!(waypoints.chunks().len(), 3);
+        assert!(Rc::ptr_eq(&waypoints.chunks()[1], &first));
+
+        // between two chunks
+        let (mut waypoints, before) = waypoints_with(&[2, 1]);
+        let last = waypoints.chunks()[1].clone();
+        let one = waypoint();
+        let one_id = one.id;
+        waypoints.insert_at(2, vec![one]);
+        assert_eq!(
+            ids(&waypoints),
+            [&before[..2], &[one_id], &before[2..]].concat()
+        );
+        assert!(Rc::ptr_eq(&waypoints.chunks()[1], &last));
+
+        // inside a chunk
+        let (mut waypoints, before) = waypoints_with(&[3]);
+        let one = waypoint();
+        let one_id = one.id;
+        waypoints.insert_at(1, vec![one]);
+        assert_eq!(
+            ids(&waypoints),
+            [&before[..1], &[one_id], &before[1..]].concat()
+        );
+
+        // at the end, or past it
+        for index in [3, 100, usize::MAX] {
+            let (mut waypoints, before) = waypoints_with(&[3]);
+            let one = waypoint();
+            let one_id = one.id;
+            waypoints.insert_at(index, vec![one]);
+            assert_eq!(ids(&waypoints), [before, vec![one_id]].concat());
+        }
+
+        // in a file without waypoints
+        let mut waypoints = Waypoints::default();
+        let one = waypoint();
+        let one_id = one.id;
+        waypoints.insert_at(0, vec![one]);
+        assert_eq!(ids(&waypoints), vec![one_id]);
+    }
+
+    #[test]
+    fn test_splice_replaces_waypoints() {
+        let (mut waypoints, before) = waypoints_with(&[2, 2]);
+        let rev = waypoints.rev_id;
+        waypoints.splice(1, 3, vec![]);
+        assert_eq!(ids(&waypoints), [before[0], before[3]]);
+        assert_ne!(waypoints.rev_id, rev);
+    }
+
+    #[test]
+    fn test_edit_changes_the_chunks_with_a_match_only() {
+        let (mut waypoints, before) = waypoints_with(&[2, 2, 1]);
+        let (first, last) = (waypoints.chunks()[0].clone(), waypoints.chunks()[2].clone());
+        let rev = waypoints.rev_id;
+        let target = before[2];
+        let changed = waypoints.edit(
+            |wpt| wpt.id == target,
+            |wpts| {
+                wpts.retain(|wpt| wpt.id != target);
+                true
+            },
+        );
+        assert!(changed);
+        assert_ne!(waypoints.rev_id, rev);
+        assert_eq!(ids(&waypoints), [&before[..2], &before[3..]].concat());
+        // the chunks without a match are the same ones, the changed one is new
+        assert!(Rc::ptr_eq(&waypoints.chunks()[0], &first));
+        assert!(Rc::ptr_eq(&waypoints.chunks()[2], &last));
+        assert_eq!(waypoints.chunks().len(), 3);
+
+        // a chunk left empty is dropped
+        let (mut waypoints, before) = waypoints_with(&[1, 2]);
+        waypoints.edit(
+            |wpt| wpt.id == before[0],
+            |wpts| {
+                wpts.clear();
+                true
+            },
+        );
+        assert_eq!(waypoints.chunks().len(), 1);
+        assert_eq!(ids(&waypoints), before[1..]);
+
+        // a chunk that is not changed is kept, and so is the revision
+        let (mut waypoints, before) = waypoints_with(&[2]);
+        let (chunk, rev) = (waypoints.chunks()[0].clone(), waypoints.rev_id);
+        assert!(!waypoints.edit(|wpt| wpt.id == before[0], |_| false));
+        assert!(Rc::ptr_eq(&waypoints.chunks()[0], &chunk));
+        assert_eq!(waypoints.rev_id, rev);
+        assert!(!waypoints.edit(|_| false, |_| true));
+    }
+}