70 lines
1.8 KiB
Rust
70 lines
1.8 KiB
Rust
use std::collections::HashMap;
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use std::ops::Range;
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#[derive(Clone)]
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pub struct ChunkReadInfo {
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pub range: Range<u64>,
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pub digest: [u8; 32],
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}
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impl ChunkReadInfo {
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#[inline]
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pub fn size(&self) -> u64 {
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self.range.end - self.range.start
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}
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}
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/// Trait to get digest list from index files
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///
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/// To allow easy iteration over all used chunks.
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pub trait IndexFile {
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fn index_count(&self) -> usize;
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fn index_digest(&self, pos: usize) -> Option<&[u8; 32]>;
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fn index_bytes(&self) -> u64;
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fn chunk_info(&self, pos: usize) -> Option<ChunkReadInfo>;
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fn index_ctime(&self) -> i64;
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fn index_size(&self) -> usize;
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/// Get the chunk index and the relative offset within it for a byte offset
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fn chunk_from_offset(&self, offset: u64) -> Option<(usize, u64)>;
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/// Compute index checksum and size
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fn compute_csum(&self) -> ([u8; 32], u64);
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/// Returns most often used chunks
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fn find_most_used_chunks(&self, max: usize) -> HashMap<[u8; 32], usize> {
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let mut map = HashMap::new();
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for pos in 0..self.index_count() {
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let digest = self.index_digest(pos).unwrap();
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let count = map.entry(*digest).or_insert(0);
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*count += 1;
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}
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let mut most_used = Vec::new();
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for (digest, count) in map {
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if count <= 1 {
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continue;
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}
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match most_used.binary_search_by_key(&count, |&(_digest, count)| count) {
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Ok(p) => most_used.insert(p, (digest, count)),
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Err(p) => most_used.insert(p, (digest, count)),
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}
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if most_used.len() > max {
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let _ = most_used.pop();
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}
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}
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let mut map = HashMap::new();
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for data in most_used {
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map.insert(data.0, data.1);
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}
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map
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}
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}
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