Prototype

Author: lemire

.gitmodules

@@ -1,6 +1,3 @@
 [submodule "dependencies/fastfilter_cpp"]
 	path = dependencies/fastfilter_cpp
 	url = https://github.com/FastFilter/fastfilter_cpp.git
-[submodule "dependencies/xor_singleheader"]
-	path = dependencies/xor_singleheader
-	url = https://github.com/FastFilter/xor_singleheader.git

Makefile

@@ -1,15 +1,13 @@
 all: build_filter query_filter
 
-dependencies/fastfilter_cpp/src/xorfilter.h:
+dependencies/fastfilter_cpp/src/xorfilter/xorfilter.h:
 	git submodule update --init --recursive
 
-dependencies/xor_singleheader/include/xorfilter.h:
-	git submodule update --init --recursive
 
-query_filter: src/query_filter.cpp src/hexutil.h          dependencies/xor_singleheader/include/xorfilter.h
+query_filter: src/query_filter.cpp src/hexutil.h  dependencies/xor_singleheader/include/xorfilter.h
 	c++ -O3 -o query_filter src/query_filter.cpp -Wall -std=c++11 -Idependencies/fastfilter_cpp/src  -Idependencies
 
-build_filter: src/build_filter.cpp dependencies/fastfilter_cpp/src/xorfilter/xorfilter.h dependencies/fastfilter_cpp/src/xorfilter/xorfilter_plus.h src/hexutil.h             dependencies/xor_singleheader/include/xorfilter.h
+build_filter: src/build_filter.cpp dependencies/fastfilter_cpp/src/xorfilter/xorfilter.h dependencies/fastfilter_cpp/src/xorfilter/xorfilter_plus.h src/hexutil.h dependencies/xor_singleheader/include/xorfilter.h
 	c++ -O3 -o build_filter src/build_filter.cpp -std=c++11 -Wall -Idependencies/fastfilter_cpp/src -Idependencies
 
 clean:

dependencies/xor_singleheader

@@ -0,0 +1,354 @@
+#ifndef BINARYFUSEFILTER_H
+#define BINARYFUSEFILTER_H
+#include <math.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#ifndef XOR_MAX_ITERATIONS
+#define XOR_MAX_ITERATIONS                                                     \
+  100 // probabillity of success should always be > 0.5 so 100 iterations is
+      // highly unlikely
+#endif
+
+/**
+ * We start with a few utilities.
+ ***/
+static inline uint64_t binary_fuse_murmur64(uint64_t h) {
+  h ^= h >> 33;
+  h *= UINT64_C(0xff51afd7ed558ccd);
+  h ^= h >> 33;
+  h *= UINT64_C(0xc4ceb9fe1a85ec53);
+  h ^= h >> 33;
+  return h;
+}
+static inline uint64_t binary_fuse_mix_split(uint64_t key, uint64_t seed) {
+  return binary_fuse_murmur64(key + seed);
+}
+static inline uint64_t binary_fuse_rotl64(uint64_t n, unsigned int c) {
+  return (n << (c & 63)) | (n >> ((-c) & 63));
+}
+static inline uint32_t binary_fuse_reduce(uint32_t hash, uint32_t n) {
+  // http://lemire.me/blog/2016/06/27/a-fast-alternative-to-the-modulo-reduction/
+  return (uint32_t)(((uint64_t)hash * n) >> 32);
+}
+static inline uint64_t binary_fuse8_fingerprint(uint64_t hash) {
+  return hash ^ (hash >> 32);
+}
+
+/**
+ * We need a decent random number generator.
+ **/
+
+// returns random number, modifies the seed
+static inline uint64_t binary_fuse_rng_splitmix64(uint64_t *seed) {
+  uint64_t z = (*seed += UINT64_C(0x9E3779B97F4A7C15));
+  z = (z ^ (z >> 30)) * UINT64_C(0xBF58476D1CE4E5B9);
+  z = (z ^ (z >> 27)) * UINT64_C(0x94D049BB133111EB);
+  return z ^ (z >> 31);
+}
+
+typedef struct binary_fuse8_s {
+  uint64_t Seed;
+  uint32_t SegmentLength;
+  uint32_t SegmentLengthMask;
+  uint32_t SegmentCount;
+  uint32_t SegmentCountLength;
+  uint32_t ArrayLength;
+  uint8_t *Fingerprints;
+} binary_fuse8_t;
+
+#ifdef _MSC_VER
+// Windows programmers who target 32-bit platform may need help:
+uint64_t binary_fuse_mulhi(uint64_t a, uint64_t b) { return __umulh(a, b); }
+#else
+uint64_t binary_fuse_mulhi(uint64_t a, uint64_t b) {
+  return ((__uint128_t)a * b) >> 64;
+}
+#endif
+
+typedef struct binary_hashes_s {
+  uint32_t h0;
+  uint32_t h1;
+  uint32_t h2;
+} binary_hashes_t;
+
+static inline binary_hashes_t binary_fuse_hash_batch(uint64_t hash,
+                                        const binary_fuse8_t *filter) {
+  uint64_t hi = binary_fuse_mulhi(hash, filter->SegmentCountLength);
+  binary_hashes_t ans;
+  ans.h0 = (uint32_t)hi;
+  ans.h1 = ans.h0 + filter->SegmentLength;
+  ans.h2 = ans.h1 + filter->SegmentLength;
+  ans.h1 ^= (uint32_t)(hash >> 18) & filter->SegmentLengthMask;
+  ans.h2 ^= (uint32_t)(hash)&filter->SegmentLengthMask;
+  return ans;
+}
+static inline uint32_t binary_fuse_hash(int index, uint64_t hash,
+                                        const binary_fuse8_t *filter) {
+    uint64_t h = binary_fuse_mulhi(hash, filter->SegmentCountLength);
+    h += index * filter->SegmentLength;
+    // keep the lower 36 bits
+    uint64_t hh = hash & ((1UL << 36) - 1);
+    // index 0: right shift by 36; index 1: right shift by 18; index 2: no shift
+    h ^= (size_t)((hh >> (36 - 18 * index)) & filter->SegmentLengthMask);
+    return h;
+}
+
+// Report if the key is in the set, with false positive rate.
+static inline bool binary_fuse8_contain(uint64_t key,
+                                        const binary_fuse8_t *filter) {
+  uint64_t hash = binary_fuse_mix_split(key, filter->Seed);
+  uint8_t f = binary_fuse8_fingerprint(hash);
+  binary_hashes_t hashes = binary_fuse_hash_batch(hash, filter);
+  f ^= filter->Fingerprints[hashes.h0] ^ filter->Fingerprints[hashes.h1] ^
+       filter->Fingerprints[hashes.h2];
+  return f == 0;
+}
+
+static inline uint32_t binary_fuse8_calculate_segment_length(uint32_t arity,
+                                                             uint32_t size) {
+  // These parameters are very sensitive. Replacing 'floor' by 'round' can
+  // substantially affect the construction time. 
+  if (arity == 3) {
+    return ((uint32_t)2) << (int)(floor(0.831 * log((double)(size)) + 0.75 +
+                                        0.5));
+  } else if (arity == 4) {
+    return ((uint32_t)1) << (int)(floor(0.936 * log((double)(size)) - 1 + 0.5));
+  } else {
+    return 65536;
+  }
+}
+
+double binary_fuse8_max(double a, double b) {
+  if (a < b) {
+    return b;
+  }
+  return a;
+}
+
+static inline double binary_fuse8_calculate_size_factor(uint32_t arity,
+                                                        uint32_t size) {
+  if (arity == 3) {
+    return binary_fuse8_max(1.125, 0.4 + 9.3 / log((double)size));
+  } else if (arity == 4) {
+    return binary_fuse8_max(1.075, 0.77 + 4.06 / log((double)size));
+  } else {
+    return 2.0;
+  }
+}
+
+// allocate enough capacity for a set containing up to 'size' elements
+// caller is responsible to call binary_fuse8_free(filter)
+static inline bool binary_fuse8_allocate(uint32_t size,
+                                         binary_fuse8_t *filter) {
+  uint32_t arity = 3;
+  filter->SegmentLength = binary_fuse8_calculate_segment_length(arity, size);
+  if (filter->SegmentLength > 262144) {
+    filter->SegmentLength = 262144;
+  }
+  filter->SegmentLengthMask = filter->SegmentLength - 1;
+  double sizeFactor = binary_fuse8_calculate_size_factor(arity, size);
+  uint32_t capacity = (uint32_t)(round((double)size * sizeFactor));
+  uint32_t initSegmentCount =
+      (capacity + filter->SegmentLength - 1) / filter->SegmentLength -
+      (arity - 1);
+  filter->ArrayLength = (initSegmentCount + arity - 1) * filter->SegmentLength;
+  filter->SegmentCount =
+      (filter->ArrayLength + filter->SegmentLength - 1) / filter->SegmentLength;
+  if (filter->SegmentCount <= arity - 1) {
+    filter->SegmentCount = 1;
+  } else {
+    filter->SegmentCount = filter->SegmentCount - (arity - 1);
+  }
+  filter->ArrayLength =
+      (filter->SegmentCount + arity - 1) * filter->SegmentLength;
+  filter->SegmentCountLength = filter->SegmentCount * filter->SegmentLength;
+  filter->Fingerprints = (uint8_t*)malloc(filter->ArrayLength);
+  return filter->Fingerprints != NULL;
+}
+
+// report memory usage
+static inline size_t binary_fuse8_size_in_bytes(const binary_fuse8_t *filter) {
+  return filter->ArrayLength * sizeof(uint8_t) + sizeof(binary_fuse8_t);
+}
+
+// release memory
+static inline void binary_fuse8_free(binary_fuse8_t *filter) {
+  free(filter->Fingerprints);
+  filter->Fingerprints = NULL;
+  filter->Seed = 0;
+  filter->SegmentLength = 0;
+  filter->SegmentLengthMask = 0;
+  filter->SegmentCount = 0;
+  filter->SegmentCountLength = 0;
+  filter->ArrayLength = 0;
+}
+
+static inline uint8_t binary_fuse8_mod3(uint8_t x) {
+    return x > 2 ? x - 3 : x;
+}
+
+// construct the filter, returns true on success, false on failure.
+// most likely, a failure is due to too high a memory usage
+// size is the number of keys
+// The caller is responsable for calling binary_fuse8_allocate(size,filter)
+// before. The caller is responsible to ensure that there are no duplicated
+// keys. The inner loop will run up to XOR_MAX_ITERATIONS times (default on
+// 100), it should never fail, except if there are duplicated keys. If it fails,
+// a return value of false is provided.
+//
+bool binary_fuse8_populate(const uint64_t *keys, uint32_t size,
+                           binary_fuse8_t *filter) {
+  uint64_t rng_counter = 0x726b2b9d438b9d4d;
+  filter->Seed = binary_fuse_rng_splitmix64(&rng_counter);
+  uint64_t *reverseOrder = (uint64_t *)calloc((size + 1), sizeof(uint64_t));
+  uint32_t capacity = filter->ArrayLength;
+  uint32_t *alone = (uint32_t *)malloc(capacity * sizeof(uint32_t));
+  uint8_t *t2count = (uint8_t *)calloc(capacity, sizeof(uint8_t));
+  uint8_t *reverseH = (uint8_t *)malloc(size * sizeof(uint8_t));
+  uint64_t *t2hash = (uint64_t *)calloc(capacity, sizeof(uint64_t));
+
+  uint32_t blockBits = 1;
+  while (((uint32_t)1 << blockBits) < filter->SegmentCount) {
+    blockBits += 1;
+  }
+  uint32_t block = ((uint32_t)1 << blockBits);
+  uint32_t *startPos = (uint32_t *)malloc((1 << blockBits) * sizeof(uint32_t));
+  uint32_t h012[5];
+
+  if ((alone == NULL) || (t2count == NULL) || (reverseH == NULL) ||
+      (t2hash == NULL) || (reverseOrder == NULL) || (startPos == NULL)) {
+    free(alone);
+    free(t2count);
+    free(reverseH);
+    free(t2hash);
+    free(reverseOrder);
+    free(startPos);
+    return false;
+  }
+  reverseOrder[size] = 1;
+  for (int loop = 0; true; ++loop) {
+    if (loop + 1 > XOR_MAX_ITERATIONS) {
+      fprintf(stderr, "Too many iterations. Are all your keys unique?");
+      free(alone);
+      free(t2count);
+      free(reverseH);
+      free(t2hash);
+      free(reverseOrder);
+      free(startPos);
+      return false;
+    }
+
+    for (uint32_t i = 0; i < block; i++) {
+      // important : i * size would overflow as a 32-bit number in some
+      // cases.
+      startPos[i] = ((uint64_t)i * size) >> blockBits;
+    }
+
+    uint64_t maskblock = block - 1; 
+    for (uint32_t i = 0; i < size; i++) {
+      uint64_t hash = binary_fuse_murmur64(keys[i] + filter->Seed);
+      uint64_t segment_index = hash >> (64 - blockBits);
+      while (reverseOrder[startPos[segment_index]] != 0) {
+        segment_index++;
+        segment_index &= maskblock;
+      }
+      reverseOrder[startPos[segment_index]] = hash;
+      startPos[segment_index]++;
+    }
+    int error = 0;
+    for (uint32_t i = 0; i < size; i++) {
+      uint64_t hash = reverseOrder[i];
+      uint32_t h0 = binary_fuse_hash(0, hash, filter);
+      t2count[h0] += 4;
+      t2hash[h0] ^= hash;
+      uint32_t h1= binary_fuse_hash(1, hash, filter);
+      t2count[h1] += 4;
+      t2count[h1] ^= 1;
+      t2hash[h1] ^= hash;
+      uint32_t h2 = binary_fuse_hash(2, hash, filter);
+      t2count[h2] += 4;
+      t2hash[h2] ^= hash;
+      t2count[h2] ^= 2;
+      error = (t2count[h0] < 4) ? 1 : error;
+      error = (t2count[h1] < 4) ? 1 : error;
+      error = (t2count[h2] < 4) ? 1 : error;
+    }
+    if(error) { continue; }
+
+    // End of key addition
+    uint32_t Qsize = 0;
+    // Add sets with one key to the queue.
+    for (uint32_t i = 0; i < capacity; i++) {
+      alone[Qsize] = i;
+      Qsize += ((t2count[i] >> 2) == 1) ? 1 : 0;
+    }
+    uint32_t stacksize = 0;
+    while (Qsize > 0) {
+      Qsize--;
+      uint32_t index = alone[Qsize];
+      if ((t2count[index] >> 2) == 1) {
+        uint64_t hash = t2hash[index];
+
+        //h012[0] = binary_fuse_hash(0, hash, filter);
+        h012[1] = binary_fuse_hash(1, hash, filter);
+        h012[2] = binary_fuse_hash(2, hash, filter);
+        h012[3] = binary_fuse_hash(0, hash, filter); // == h012[0];
+        h012[4] = h012[1];
+        uint8_t found = t2count[index] & 3;
+        reverseH[stacksize] = found;
+        reverseOrder[stacksize] = hash;
+        stacksize++;
+        uint32_t other_index1 = h012[found + 1];
+        alone[Qsize] = other_index1;
+        Qsize += ((t2count[other_index1] >> 2) == 2 ? 1 : 0);
+
+        t2count[other_index1] -= 4;
+        t2count[other_index1] ^= binary_fuse8_mod3(found + 1); 
+        t2hash[other_index1] ^= hash;
+
+        uint32_t other_index2 = h012[found + 2];
+        alone[Qsize] = other_index2;
+        Qsize += ((t2count[other_index2] >> 2) == 2 ? 1 : 0);
+        t2count[other_index2] -= 4;
+        t2count[other_index2] ^= binary_fuse8_mod3(found + 2);
+        t2hash[other_index2] ^= hash;
+      }
+    }
+    if (stacksize == size) {
+      // success
+      break;
+    }
+    memset(reverseOrder, 0, sizeof(uint64_t[size]));
+    memset(t2count, 0, sizeof(uint8_t[capacity]));
+    memset(t2hash, 0, sizeof(uint64_t[capacity]));
+    filter->Seed = binary_fuse_rng_splitmix64(&rng_counter);
+  }
+
+  for (uint32_t i = size - 1; i < size; i--) {
+    // the hash of the key we insert next
+    uint64_t hash = reverseOrder[i];
+    uint8_t xor2 = binary_fuse8_fingerprint(hash);
+    uint8_t found = reverseH[i];
+    h012[0] = binary_fuse_hash(0, hash, filter);
+    h012[1] = binary_fuse_hash(1, hash, filter);
+    h012[2] = binary_fuse_hash(2, hash, filter);
+    h012[3] = h012[0];
+    h012[4] = h012[1];
+    filter->Fingerprints[h012[found]] = xor2 ^
+                                        filter->Fingerprints[h012[found + 1]] ^
+                                        filter->Fingerprints[h012[found + 2]];
+  }
+  free(alone);
+  free(t2count);
+  free(reverseH);
+  free(t2hash);
+  free(reverseOrder);
+  free(startPos);
+  return true;
+}
+
+#endif