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use base64::engine::general_purpose::STANDARD as BASE64_ENCODER;
use base64::engine::Engine as _;
use super::parser::{DecodedImage, KittyError, KittyErrorCode, KittyFormat};
use std::collections::HashMap;
pub const DEFAULT_KITTY_STORE_QUOTA_BYTES: usize = 335_544_320;
pub type InternalImageId = u64;
#[derive(Debug, Clone, PartialEq)]
pub struct KittyImage {
pub rgba: Vec<u8>,
pub width: u32,
pub height: u32,
pub scaled_variants: HashMap<(u16, u16), Vec<u8>>,
}
#[derive(Debug, Clone)]
struct StoredImage {
image: KittyImage,
refcount: usize,
lru_stamp: u64,
base64_cache: HashMap<Option<(u16, u16)>, String>,
}
#[derive(Debug, Clone)]
pub struct KittyImageStore {
images: HashMap<InternalImageId, StoredImage>,
next_image_id: InternalImageId,
next_lru_stamp: u64,
quota_bytes: usize,
total_bytes: usize,
next_placement_uid: u64,
}
impl Default for KittyImageStore {
fn default() -> Self {
Self::with_quota(DEFAULT_KITTY_STORE_QUOTA_BYTES)
}
}
impl KittyImageStore {
pub fn with_quota(quota_bytes: usize) -> Self {
KittyImageStore {
images: HashMap::new(),
next_image_id: 1,
next_lru_stamp: 0,
quota_bytes,
total_bytes: 0,
next_placement_uid: 1,
}
}
pub fn next_placement_uid(&mut self) -> u64 {
let uid = self.next_placement_uid;
self.next_placement_uid += 1;
uid
}
pub fn store_image(&mut self, image: DecodedImage) -> Result<InternalImageId, KittyError> {
let (rgba, width, height) = Self::normalize_to_rgba(image);
let size = rgba.len();
if size > self.quota_bytes {
return Err(KittyError {
code: KittyErrorCode::Einval,
message: "image exceeds storage quota".to_owned(),
image_id: None,
image_number: None,
placement_id: None,
quiet: 0,
});
}
self.evict_to_fit(size, None);
let id = self.next_image_id;
self.next_image_id += 1;
let lru_stamp = self.bump_lru();
self.images.insert(
id,
StoredImage {
image: KittyImage {
rgba,
width,
height,
scaled_variants: HashMap::new(),
},
refcount: 0,
lru_stamp,
base64_cache: HashMap::new(),
},
);
self.total_bytes += size;
Ok(id)
}
pub fn get(&self, id: InternalImageId) -> Option<&KittyImage> {
self.images.get(&id).map(|stored| &stored.image)
}
pub fn scaled_variant(&self, id: InternalImageId, cells: (u16, u16)) -> Option<&[u8]> {
self.images
.get(&id)
.and_then(|stored| stored.image.scaled_variants.get(&cells))
.map(|bytes| bytes.as_slice())
}
pub fn touch(&mut self, id: InternalImageId) {
let lru_stamp = self.bump_lru();
if let Some(stored) = self.images.get_mut(&id) {
stored.lru_stamp = lru_stamp;
}
}
pub fn add_placement_ref(&mut self, id: InternalImageId) {
let lru_stamp = self.bump_lru();
if let Some(stored) = self.images.get_mut(&id) {
stored.refcount += 1;
stored.lru_stamp = lru_stamp;
}
}
pub fn remove_placement_ref(&mut self, id: InternalImageId) {
if let Some(stored) = self.images.get_mut(&id) {
stored.refcount = stored.refcount.saturating_sub(1);
}
}
pub fn free(&mut self, id: InternalImageId) {
let should_remove = match self.images.get_mut(&id) {
Some(stored) => {
stored.refcount = stored.refcount.saturating_sub(1);
stored.refcount == 0
},
None => false,
};
if should_remove {
self.remove_entry(id);
}
}
pub fn base64_for(
&mut self,
id: InternalImageId,
variant: Option<(u16, u16)>,
) -> Option<String> {
let stored = self.images.get_mut(&id)?;
if let Some(cached) = stored.base64_cache.get(&variant) {
return Some(cached.clone());
}
let bytes = match variant {
Some(cells) => stored.image.scaled_variants.get(&cells)?,
None => &stored.image.rgba,
};
let encoded = BASE64_ENCODER.encode(bytes);
stored.base64_cache.insert(variant, encoded.clone());
Some(encoded)
}
pub fn add_scaled_variant(&mut self, id: InternalImageId, cells: (u16, u16), bytes: Vec<u8>) {
let lru_stamp = self.bump_lru();
let inserted = match self.images.get_mut(&id) {
Some(stored) => {
let new_len = bytes.len();
let old_len = stored
.image
.scaled_variants
.insert(cells, bytes)
.map(|old| old.len())
.unwrap_or(0);
stored.base64_cache.remove(&Some(cells));
stored.lru_stamp = lru_stamp;
Some((old_len, new_len))
},
None => None,
};
if let Some((old_len, new_len)) = inserted {
self.total_bytes = self.total_bytes - old_len + new_len;
if self.total_bytes > self.quota_bytes {
self.evict_to_fit(0, Some(id));
}
}
}
pub fn refcount(&self, id: InternalImageId) -> Option<usize> {
self.images.get(&id).map(|stored| stored.refcount)
}
pub fn total_bytes(&self) -> usize {
self.total_bytes
}
pub fn image_count(&self) -> usize {
self.images.len()
}
fn bump_lru(&mut self) -> u64 {
self.next_lru_stamp += 1;
self.next_lru_stamp
}
fn stored_image_bytes(stored: &StoredImage) -> usize {
stored.image.rgba.len()
+ stored
.image
.scaled_variants
.values()
.map(|bytes| bytes.len())
.sum::<usize>()
}
fn remove_entry(&mut self, id: InternalImageId) {
if let Some(stored) = self.images.remove(&id) {
self.total_bytes -= Self::stored_image_bytes(&stored);
}
}
fn evict_to_fit(&mut self, incoming_bytes: usize, protected: Option<InternalImageId>) {
while self.total_bytes + incoming_bytes > self.quota_bytes {
let candidate = self
.images
.iter()
.filter(|(id, stored)| stored.refcount == 0 && Some(**id) != protected)
.min_by_key(|(_, stored)| stored.lru_stamp)
.map(|(id, _)| *id);
match candidate {
Some(id) => self.remove_entry(id),
None => break,
}
}
}
fn normalize_to_rgba(image: DecodedImage) -> (Vec<u8>, u32, u32) {
match image.format {
KittyFormat::Rgb24 => {
let mut rgba = Vec::with_capacity(image.bytes.len() / 3 * 4);
for pixel in image.bytes.chunks_exact(3) {
rgba.extend_from_slice(pixel);
rgba.push(255);
}
(rgba, image.width, image.height)
},
KittyFormat::Rgba32 | KittyFormat::Png => (image.bytes, image.width, image.height),
}
}
}
#[cfg(test)]
#[path = "./unit/store_tests.rs"]
mod store_tests;
|
