thin-provisioning-tools/caching/cache_metadata_size.cc
2017-09-18 16:10:56 +01:00

176 lines
4.1 KiB
C++

#include "version.h"
#include "caching/commands.h"
#include <boost/lexical_cast.hpp>
#include <boost/optional.hpp>
#include <iostream>
#include <getopt.h>
#include <stdint.h>
#include <stdexcept>
using namespace caching;
using namespace std;
//----------------------------------------------------------------
cache_metadata_size_cmd::flags::flags()
: max_hint_width(4) {
// Dance around some spurious compiler warnings
device_size = 0;
block_size = 0;
nr_blocks = 0;
device_size.reset();
block_size.reset();
nr_blocks.reset();
}
cache_metadata_size_cmd::parse_result
cache_metadata_size_cmd::parse_command_line(string const &prog_name, int argc, char **argv, flags &fs)
{
int c;
char const short_opts[] = "hV";
option const long_opts[] = {
{ "block-size", required_argument, NULL, 0 },
{ "device-size", required_argument, NULL, 1 },
{ "nr-blocks", required_argument, NULL, 2 },
{ "max-hint-width", required_argument, NULL, 3 },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{ NULL, no_argument, NULL, 0 }
};
while ((c = getopt_long(argc, argv, short_opts, long_opts, NULL)) != -1) {
switch (c) {
case 0:
fs.block_size = boost::lexical_cast<uint32_t>(optarg);
break;
case 1:
fs.device_size = boost::lexical_cast<uint64_t>(optarg);
break;
case 2:
fs.nr_blocks = boost::lexical_cast<uint64_t>(optarg);
break;
case 3:
fs.max_hint_width = boost::lexical_cast<uint32_t>(optarg);
break;
case 'h':
usage(cout);
return FINISH;
break;
case 'V':
cout << THIN_PROVISIONING_TOOLS_VERSION << endl;
return FINISH;
break;
default:
usage(cerr);
throw runtime_error("Invalid command line");
break;
}
}
return CONTINUE;
}
uint64_t
cache_metadata_size_cmd::get_nr_blocks(flags &fs)
{
if (fs.device_size) {
if (!fs.block_size)
throw runtime_error("If you specify --device-size you must also give --block-size.");
uint64_t nr_blocks = *fs.device_size / *fs.block_size;
if (fs.nr_blocks) {
if (nr_blocks != *fs.nr_blocks)
throw runtime_error(
"Contradictory arguments given, --nr-blocks doesn't match the --device-size and --block-size.");
}
return nr_blocks;
}
if (fs.block_size && !fs.device_size)
throw runtime_error("If you specify --block-size you must also give --device-size.");
if (fs.nr_blocks)
return *fs.nr_blocks;
throw runtime_error("Please specify either --device-size and --block-size, or --nr-blocks.");
}
uint64_t
cache_metadata_size_cmd::meg(uint64_t n)
{
return n * 2048;
}
uint64_t
cache_metadata_size_cmd::calc_size(uint64_t nr_blocks, uint32_t max_hint_width)
{
uint64_t const SECTOR_SIZE = 512;
uint64_t const TRANSACTION_OVERHEAD = meg(4);
uint64_t const BYTES_PER_BLOCK = 16;
uint64_t const HINT_OVERHEAD_PER_BLOCK = 8;
uint64_t mapping_size = (nr_blocks * BYTES_PER_BLOCK) / SECTOR_SIZE;
uint64_t hint_size = (nr_blocks * (max_hint_width + HINT_OVERHEAD_PER_BLOCK)) / SECTOR_SIZE;
return TRANSACTION_OVERHEAD + mapping_size + hint_size;
}
//----------------------------------------------------------------
cache_metadata_size_cmd::cache_metadata_size_cmd()
: command("cache_metadata_size")
{
}
void
cache_metadata_size_cmd::usage(ostream &out) const
{
out << "Usage: " << get_name() << " [options]" << endl
<< "Options:" << endl
<< " {-h|--help}" << endl
<< " {-V|--version}" << endl
<< " {--block-size <sectors>}" << endl
<< " {--device-size <sectors>}" << endl
<< " {--nr-blocks <natural>}" << endl
<< " {--max-hint-width <nr bytes>}" << endl << endl
<< "These all relate to the size of the fast device (eg, SSD), rather" << endl
<< "than the whole cached device." << endl;
}
int
cache_metadata_size_cmd::run(int argc, char **argv)
{
flags fs;
try {
switch (parse_command_line(argv[0], argc, argv, fs)) {
case FINISH:
return 0;
case CONTINUE:
break;
}
uint64_t nr_blocks = get_nr_blocks(fs);
cout << calc_size(nr_blocks, fs.max_hint_width) << " sectors" << endl;
} catch (std::exception const &e) {
cerr << e.what() << "\n";
return 1;
}
return 0;
}
//----------------------------------------------------------------