fork of https://github.com/oxigraph/rocksdb and https://github.com/facebook/rocksdb for nextgraph and oxigraph
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
64 lines
2.0 KiB
64 lines
2.0 KiB
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
|
|
// This source code is licensed under both the GPLv2 (found in the
|
|
// COPYING file in the root directory) and Apache 2.0 License
|
|
// (found in the LICENSE.Apache file in the root directory).
|
|
|
|
#include "dynamic_bloom.h"
|
|
|
|
#include <algorithm>
|
|
|
|
#include "memory/allocator.h"
|
|
#include "port/port.h"
|
|
#include "rocksdb/slice.h"
|
|
#include "util/hash.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
namespace {
|
|
|
|
uint32_t roundUpToPow2(uint32_t x) {
|
|
uint32_t rv = 1;
|
|
while (rv < x) {
|
|
rv <<= 1;
|
|
}
|
|
return rv;
|
|
}
|
|
|
|
}
|
|
|
|
DynamicBloom::DynamicBloom(Allocator* allocator, uint32_t total_bits,
|
|
uint32_t num_probes,
|
|
size_t huge_page_tlb_size, Logger* logger)
|
|
// Round down, except round up with 1
|
|
: kNumDoubleProbes((num_probes + (num_probes == 1)) / 2) {
|
|
assert(num_probes % 2 == 0); // limitation of current implementation
|
|
assert(num_probes <= 10); // limitation of current implementation
|
|
assert(kNumDoubleProbes > 0);
|
|
|
|
// Determine how much to round off + align by so that x ^ i (that's xor) is
|
|
// a valid u64 index if x is a valid u64 index and 0 <= i < kNumDoubleProbes.
|
|
uint32_t block_bytes = /*bytes/u64*/ 8 *
|
|
/*u64s*/ std::max(1U, roundUpToPow2(kNumDoubleProbes));
|
|
kLen = (total_bits + (/*bits/byte*/ 8 * block_bytes - 1)) /
|
|
/*bits/u64*/ 64;
|
|
assert(kLen > 0);
|
|
|
|
uint32_t sz = kLen * /*bytes/u64*/ 8;
|
|
// Padding to correct for allocation not originally aligned on block_bytes
|
|
// boundary
|
|
sz += block_bytes - 1;
|
|
assert(allocator);
|
|
|
|
char* raw = allocator->AllocateAligned(sz, huge_page_tlb_size, logger);
|
|
memset(raw, 0, sz);
|
|
auto block_offset = reinterpret_cast<uintptr_t>(raw) % block_bytes;
|
|
if (block_offset > 0) {
|
|
// Align on block_bytes boundary
|
|
raw += block_bytes - block_offset;
|
|
}
|
|
static_assert(sizeof(std::atomic<uint64_t>) == sizeof(uint64_t),
|
|
"Expecting zero-space-overhead atomic");
|
|
data_ = reinterpret_cast<std::atomic<uint64_t>*>(raw);
|
|
}
|
|
|
|
} // rocksdb
|
|
|