[io_generator] Add random map to avoid generating repeated addresses

This commit is contained in:
Ming-Hung Tsai 2020-07-10 15:19:38 +08:00
parent e9055f5d7d
commit aabc3a9dbc

View File

@ -1,4 +1,5 @@
#include "base/io_generator.h"
#include "persistent-data/run_set.h"
#include <stdexcept>
#include <cstdlib>
#include <cstring>
@ -69,17 +70,37 @@ namespace {
sector_t block_size)
: block_begin_(offset / block_size),
nr_blocks_(size / block_size),
block_size_(block_size) {
block_size_(block_size),
nr_generated_(0) {
}
sector_t next_offset() {
return ((std::rand() % nr_blocks_) + block_begin_) * block_size_;
uint64_t blocknr;
bool found = true;
while (found) {
blocknr = (std::rand() % nr_blocks_) + block_begin_;
found = io_map_.member(blocknr);
}
io_map_.add(blocknr);
++nr_generated_;
// wrap-around
if (nr_generated_ == nr_blocks_) {
io_map_.clear();
nr_generated_ = 0;
}
return blocknr * block_size_;
}
private:
uint64_t block_begin_;
uint64_t nr_blocks_;
unsigned block_size_;
base::run_set<uint64_t> io_map_;
uint64_t nr_generated_;
};
//--------------------------------