thin-provisioning-tools/era/xml_format.cc
2014-08-06 16:30:38 +01:00

171 lines
3.9 KiB
C++

#include "era/xml_format.h"
#include "base/indented_stream.h"
#include "base/xml_utils.h"
#include <expat.h>
using namespace boost;
using namespace era;
using namespace persistent_data;
using namespace std;
using namespace xml_utils;
//----------------------------------------------------------------
namespace {
class xml_emitter : public emitter {
public:
xml_emitter(ostream &out)
: out_(out) {
}
void begin_superblock(std::string const &uuid,
uint32_t block_size,
pd::block_address nr_blocks,
uint32_t current_era) {
out_.indent();
out_ << "<superblock uuid=\"" << uuid << "\""
<< " block_size=\"" << block_size << "\""
<< " nr_blocks=\"" << nr_blocks << "\""
<< " current_era=\"" << current_era << "\">";
out_ << endl;
out_.inc();
}
void end_superblock() {
out_.dec();
out_.indent();
out_ << "</superblock>" << endl;
}
void begin_writeset(uint32_t era, uint32_t nr_bits) {
out_.indent();
out_ << "<writeset era=\"" << era << "\""
<< " nr_bits=\"" << nr_bits << "\">" << endl;
out_.inc();
}
void writeset_bit(uint32_t bit, bool value) {
out_.indent();
// FIXME: collect all the bits, then uuencode
out_ << "<bit bit=\"" << bit << "\" value=\"" << value << "\">" << endl;
}
void end_writeset() {
out_.dec();
out_.indent();
out_ << "</writeset>" << endl;
}
void begin_era_array() {
out_.indent();
out_ << "<era_array>" << endl;
out_.inc();
}
void era(pd::block_address block, uint32_t era) {
out_.indent();
out_ << "<era block=\"" << block
<< "\" era=\"" << era << "\">" << endl;
}
void end_era_array() {
out_.dec();
out_.indent();
out_ << "</era_array>" << endl;
}
private:
indented_stream out_;
};
//--------------------------------
// Parser
//--------------------------------
void start_tag(void *data, char const *el, char const **attr) {
emitter *e = static_cast<emitter *>(data);
attributes a;
build_attributes(a, attr);
if (!strcmp(el, "superblock"))
e->begin_superblock(get_attr<string>(a, "uuid"),
get_attr<uint32_t>(a, "block_size"),
get_attr<pd::block_address>(a, "nr_blocks"),
get_attr<uint32_t>(a, "current_era"));
else if (!strcmp(el, "writeset"))
e->begin_writeset(get_attr<uint32_t>(a, "era"),
get_attr<uint32_t>(a, "nr_bits"));
else if (!strcmp(el, "bit"))
e->writeset_bit(get_attr<uint32_t>(a, "bit"),
get_attr<bool>(a, "value"));
else if (!strcmp(el, "era_array"))
e->begin_era_array();
else if (!strcmp(el, "era"))
e->era(get_attr<pd::block_address>(a, "block"),
get_attr<uint32_t>(a, "era"));
else
throw runtime_error("unknown tag type");
}
void end_tag(void *data, const char *el) {
emitter *e = static_cast<emitter *>(data);
if (!strcmp(el, "superblock"))
e->end_superblock();
else if (!strcmp(el, "writeset"))
e->end_writeset();
else if (!strcmp(el, "era_array"))
e->end_era_array();
else
throw runtime_error("unknown tag type");
}
}
//----------------------------------------------------------------
emitter::ptr
era::create_xml_emitter(std::ostream &out)
{
return emitter::ptr(new xml_emitter(out));
}
void
era::parse_xml(std::istream &in, emitter::ptr e)
{
XML_Parser parser = XML_ParserCreate(NULL);
if (!parser)
throw runtime_error("couldn't create xml parser");
XML_SetUserData(parser, e.get());
XML_SetElementHandler(parser, start_tag, end_tag);
while (!in.eof()) {
char buffer[4096];
in.read(buffer, sizeof(buffer));
size_t len = in.gcount();
int done = in.eof();
if (!XML_Parse(parser, buffer, len, done)) {
ostringstream out;
out << "Parse error at line "
<< XML_GetCurrentLineNumber(parser)
<< ":\n"
<< XML_ErrorString(XML_GetErrorCode(parser))
<< endl;
throw runtime_error(out.str());
}
}
}
//----------------------------------------------------------------