thin-provisioning-tools/contrib/tmakatos_emitter.cc
2016-03-24 14:44:13 +00:00

152 lines
3.1 KiB
C++

#include "thin-provisioning/emitter.h"
#include <iostream>
#include <climits>
using namespace std;
using namespace thin_provisioning;
//----------------------------------------------------------------
namespace {
template <typename T>
std::ostream &operator << (ostream &out, boost::optional<T> const &maybe) {
if (maybe)
out << *maybe;
return out;
}
//------------------------------------------------
// binary generator
//------------------------------------------------
class binary_emitter : public emitter {
public:
binary_emitter(ostream &out)
: out_(out) {
}
void begin_superblock(string const &uuid,
uint64_t time,
uint64_t trans_id,
boost::optional<uint32_t> flags,
boost::optional<uint32_t> version,
uint32_t data_block_size,
uint64_t nr_data_blocks,
boost::optional<uint64_t> metadata_snap) {
}
void end_superblock() {
}
void begin_device(uint32_t dev_id,
uint64_t mapped_blocks,
uint64_t trans_id,
uint64_t creation_time,
uint64_t snap_time) {
cur = 0;
bitmap = 0;
}
void end_device() {
emit_bmp(true);
}
void begin_named_mapping(string const &name) { }
void end_named_mapping() { }
void identifier(string const &name) { }
void range_map(uint64_t origin_begin, uint64_t, uint32_t,
uint64_t len) {
uint64_t n = origin_begin / unit;
uint64_t i;
assert(n >= cur);
assert(len > 0);
/*
* Cover the gap between the last emitted unit and the current one.
*/
if (n > cur)
do { emit_bmp(); } while (cur < n);
/*
* Emit partial unit.
*/
if (origin_begin & (unit - 1)) {
const uint64_t j = min(len,
(origin_begin & ~(unit - 1)) + unit - origin_begin);
for (i = origin_begin; i < origin_begin + j; i++)
bitmap |= 1ULL << (i & (unit - 1));
if (j == len)
return;
emit_bmp();
len -= j;
origin_begin = i;
}
/*
* Emit full units until end.
*/
n = (origin_begin + len) / unit;
while (cur < n) {
bitmap = ~0;
emit_bmp();
len -= unit;
}
origin_begin = cur * unit;
/*
* Emit final unit.
*/
for (i = origin_begin; i < origin_begin + len; i++)
bitmap |= 1ULL << (i & (unit - 1));
}
void single_map(uint64_t origin_block, uint64_t, uint32_t) {
range_map(origin_block, 0, 0, 1);
}
private:
ostream &out_;
/**
* The entire virtual block allocation bitmap is segmented into 64-bit
* sub-bitmaps (units).
*/
uint64_t bitmap;
/*
* Pointer to the current sub-bitmap (unit) that has not yet been
* emitted.
*/
uint64_t cur;
/**
* Unit (sub-bitmap) size. Must be a power of 2.
*/
static const size_t unit = sizeof bitmap * CHAR_BIT;
void emit_bmp(bool omit_if_zero = false) {
if (!bitmap && omit_if_zero)
out_.write((const char*)&bitmap, sizeof bitmap);
bitmap = 0;
cur++;
}
};
}
//----------------------------------------------------------------
extern "C" {
emitter::ptr create_emitter(ostream &out) {
return emitter::ptr(new binary_emitter(out));
}
}
//----------------------------------------------------------------