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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
use crate::display_item::*;
use crate::display_list::*;
use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
#[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
pub struct CachedDisplayItem {
item: DisplayItem,
data: Vec<u8>,
}
impl CachedDisplayItem {
pub fn display_item(&self) -> &DisplayItem {
&self.item
}
pub fn data_as_item_range<T>(&self) -> ItemRange<T> {
ItemRange::new(&self.data)
}
}
impl MallocSizeOf for CachedDisplayItem {
fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
self.data.size_of(ops)
}
}
impl From<DisplayItemRef<'_, '_>> for CachedDisplayItem {
fn from(item_ref: DisplayItemRef) -> Self {
let item = item_ref.item();
match item {
DisplayItem::Text(..) => CachedDisplayItem {
item: *item,
data: item_ref.glyphs().bytes().to_vec(),
},
_ => CachedDisplayItem {
item: *item,
data: Vec::new(),
},
}
}
}
#[derive(Clone, Deserialize, MallocSizeOf, Serialize)]
struct CacheEntry {
items: Vec<CachedDisplayItem>,
occupied: bool,
}
#[derive(Clone, Deserialize, MallocSizeOf, Serialize)]
pub struct DisplayItemCache {
entries: Vec<CacheEntry>,
}
impl DisplayItemCache {
fn add_item(&mut self, key: ItemKey, item: CachedDisplayItem) {
let entry = &mut self.entries[key as usize];
entry.items.push(item);
entry.occupied = true;
}
fn clear_entry(&mut self, key: ItemKey) {
let entry = &mut self.entries[key as usize];
entry.items.clear();
entry.occupied = false;
}
fn grow_if_needed(&mut self, capacity: usize) {
if capacity > self.entries.len() {
self.entries.resize_with(capacity, || CacheEntry {
items: Vec::new(),
occupied: false,
});
}
}
pub fn get_items(&self, key: ItemKey) -> &[CachedDisplayItem] {
let entry = &self.entries[key as usize];
debug_assert!(entry.occupied);
entry.items.as_slice()
}
pub fn new() -> Self {
Self {
entries: Vec::new(),
}
}
pub fn update(&mut self, display_list: &BuiltDisplayList) {
self.grow_if_needed(display_list.cache_size());
let mut iter = display_list.cache_data_iter();
let mut current_key: Option<ItemKey> = None;
while let Some(item) = iter.next() {
if let DisplayItem::RetainedItems(key) = item.item() {
current_key = Some(*key);
self.clear_entry(*key);
continue;
}
let key = current_key.expect("Missing RetainedItems marker");
let cached_item = CachedDisplayItem::from(item);
self.add_item(key, cached_item);
}
}
}