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Refactor xor8 code #5

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Refactor xor8 code #5

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f0545a0
make fingerprint update logic more readable
juanbono Dec 26, 2019
c7f7bf7
Merge branch 'master' of github.com:juanbono/xor-filter into refactor
juanbono Dec 26, 2019
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56 changes: 29 additions & 27 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@ impl Xor8 {
let mut q0: Vec<KeyIndex> = vec![Default::default(); block_length];
let mut q1: Vec<KeyIndex> = vec![Default::default(); block_length];
let mut q2: Vec<KeyIndex> = vec![Default::default(); block_length];

let mut sets0: Vec<XorSet> = vec![Default::default(); block_length];
let mut sets1: Vec<XorSet> = vec![Default::default(); block_length];
let mut sets2: Vec<XorSet> = vec![Default::default(); block_length];
Expand Down Expand Up @@ -88,24 +88,23 @@ impl Xor8 {
continue; // not actually possible after the initial scan
}
let hash = keyindex_var.hash;
let h1 = filter.h1(hash);
let h2 = filter.h2(hash);
let h1 = filter.h1(hash) as usize;
let h2 = filter.h2(hash) as usize;
stack[stack_size] = keyindex_var;
stack_size += 1;
sets1[h1 as usize].xormask ^= hash;

sets1[h1 as usize].count -= 1;
if sets1[h1 as usize].count == 1 {
q1[q1_size].index = h1;
q1[q1_size].hash = sets1[h1 as usize].xormask;
sets1[h1].xormask ^= hash;
sets1[h1].count -= 1;
if sets1[h1].count == 1 {
q1[q1_size].index = h1 as u32;
q1[q1_size].hash = sets1[h1].xormask;
q1_size += 1;
}

sets2[h2 as usize].xormask ^= hash;
sets2[h2 as usize].count -= 1;
if sets2[h2 as usize].count == 1 {
q2[q2_size].index = h2;
q2[q2_size].hash = sets2[h2 as usize].xormask;
sets2[h2].xormask ^= hash;
sets2[h2].count -= 1;
if sets2[h2].count == 1 {
q2[q2_size].index = h2 as u32;
q2[q2_size].hash = sets2[h2].xormask;
q2_size += 1;
}
}
Expand All @@ -125,7 +124,7 @@ impl Xor8 {
stack_size += 1;
sets0[h0].xormask ^= hash;
sets0[h0].count -= 1;
if sets0[h0 as usize].count == 1 {
if sets0[h0].count == 1 {
q0[q0_size].index = h0 as u32;
q0[q0_size].hash = sets0[h0].xormask;
q0_size += 1;
Expand Down Expand Up @@ -174,9 +173,9 @@ impl Xor8 {
break; // success
}

sets0 = sets0.iter().map(|_| Default::default()).collect();
sets1 = sets1.iter().map(|_| Default::default()).collect();
sets2 = sets2.iter().map(|_| Default::default()).collect();
sets0 = vec![Default::default(); sets0.len()];
sets1 = vec![Default::default(); sets1.len()];
sets2 = vec![Default::default(); sets2.len()];
filter.seed = splitmix64(&mut rngcounter);
}

Expand All @@ -186,17 +185,20 @@ impl Xor8 {
stack_size -= 1;
let ki = stack[stack_size];
let mut val = fingerprint(ki.hash) as u8;
if ki.index < filter.block_length {
val ^= filter.fingerprints[(filter.h1(ki.hash) + filter.block_length) as usize]
^ filter.fingerprints[(filter.h2(ki.hash) + 2 * filter.block_length) as usize];
} else if ki.index < 2 * filter.block_length {
val ^= filter.fingerprints[filter.h0(ki.hash) as usize]
^ filter.fingerprints[(filter.h2(ki.hash) + 2 * filter.block_length) as usize];
let (length, ki_index) = (filter.block_length as usize, ki.index as usize);
let (h0, h1, h2) = (
filter.h0(ki.hash) as usize,
filter.h1(ki.hash) as usize,
filter.h2(ki.hash) as usize,
);
if ki_index < length {
val ^= filter.fingerprints[h1 + length] ^ filter.fingerprints[h2 + 2 * length];
} else if ki_index < 2 * length {
val ^= filter.fingerprints[h0] ^ filter.fingerprints[h2 + 2 * length];
} else {
val ^= filter.fingerprints[filter.h0(ki.hash) as usize]
^ filter.fingerprints[(filter.h1(ki.hash) + filter.block_length) as usize];
val ^= filter.fingerprints[h0] ^ filter.fingerprints[h1 + length];
}
filter.fingerprints[ki.index as usize] = val;
filter.fingerprints[ki_index] = val;
}
filter
}
Expand Down