thin-provisioning-tools/caching/metadata_dump.cc
2013-10-09 10:49:53 +01:00

145 lines
3.5 KiB
C++

#include "caching/metadata_dump.h"
#include <set>
using namespace std;
using namespace caching;
//----------------------------------------------------------------
namespace {
string to_string(unsigned char const *data) {
// FIXME: we're assuming the data is zero terminated here
return std::string(reinterpret_cast<char const *>(data));
}
void raise_metadata_damage() {
throw std::runtime_error("metadata contains errors (run cache_check for details).\n"
"perhaps you wanted to run with --repair");
}
//--------------------------------
class mapping_emitter : public mapping_visitor {
public:
mapping_emitter(emitter::ptr e, set<block_address> &valid_blocks)
: e_(e),
valid_blocks_(valid_blocks) {
}
void visit(block_address cblock, mapping const &m) {
if (m.flags_ & M_VALID) {
e_->mapping(cblock, m.oblock_, m.flags_ & M_DIRTY);
mark_valid(cblock);
}
}
private:
void mark_valid(block_address cblock) {
valid_blocks_.insert(cblock);
}
emitter::ptr e_;
set<block_address> &valid_blocks_;
};
struct ignore_mapping_damage : public mapping_array_damage::damage_visitor {
virtual void visit(mapping_array_damage::missing_mappings const &d) {}
virtual void visit(mapping_array_damage::invalid_mapping const &d) {}
};
class fatal_mapping_damage : public mapping_array_damage::damage_visitor {
public:
virtual void visit(mapping_array_damage::missing_mappings const &d) {
raise_metadata_damage();
}
virtual void visit(mapping_array_damage::invalid_mapping const &d) {
raise_metadata_damage();
}
};
//--------------------------------
class hint_emitter : public hint_visitor {
public:
hint_emitter(emitter::ptr e, set<block_address> valid_blocks)
: e_(e),
valid_blocks_(valid_blocks) {
}
virtual void visit(block_address cblock, std::vector<unsigned char> const &data) {
if (valid(cblock))
e_->hint(cblock, data);
}
private:
bool valid(block_address cblock) const {
return valid_blocks_.find(cblock) != valid_blocks_.end();
}
emitter::ptr e_;
set<block_address> &valid_blocks_;
};
struct ignore_hint_damage : public hint_array_damage::damage_visitor {
virtual void visit(hint_array_damage::missing_hints const &d) {}
};
class fatal_hint_damage : public hint_array_damage::damage_visitor {
virtual void visit(hint_array_damage::missing_hints const &d) {
raise_metadata_damage();
}
};
}
//----------------------------------------------------------------
void
caching::metadata_dump(metadata::ptr md, emitter::ptr e, bool repair)
{
set<block_address> valid_blocks;
superblock const &sb = md->sb_;
e->begin_superblock(to_string(sb.uuid), sb.data_block_size,
sb.cache_blocks, to_string(sb.policy_name),
sb.policy_hint_size);
e->begin_mappings();
{
namespace mad = mapping_array_damage;
mapping_emitter me(e, valid_blocks);
ignore_mapping_damage ignore;
fatal_mapping_damage fatal;
mad::damage_visitor &dv = repair ?
static_cast<mad::damage_visitor &>(ignore) :
static_cast<mad::damage_visitor &>(fatal);
walk_mapping_array(*md->mappings_, me, dv);
}
e->end_mappings();
// walk hints
e->begin_hints();
{
using namespace hint_array_damage;
hint_emitter he(e, valid_blocks);
ignore_hint_damage ignore;
fatal_hint_damage fatal;
damage_visitor &dv = repair ?
static_cast<damage_visitor &>(ignore) :
static_cast<damage_visitor &>(fatal);
md->hints_->walk(he, dv);
}
e->end_hints();
// FIXME: walk discards
e->end_superblock();
}
//----------------------------------------------------------------