thin-provisioning-tools/thin-provisioning/xml_format.cc
2013-06-25 13:48:02 +01:00

302 lines
7.6 KiB
C++

// Copyright (C) 2011 Red Hat, Inc. All rights reserved.
//
// This file is part of the thin-provisioning-tools source.
//
// thin-provisioning-tools is free software: you can redistribute it
// and/or modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation, either version 3 of
// the License, or (at your option) any later version.
//
// thin-provisioning-tools is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty
// of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with thin-provisioning-tools. If not, see
// <http://www.gnu.org/licenses/>.
#include "xml_format.h"
#include <boost/lexical_cast.hpp>
#include <boost/optional.hpp>
#include <expat.h>
#include <iostream>
#include <map>
#include <sstream>
#include <stdexcept>
#include <string.h>
using namespace std;
using namespace thin_provisioning;
namespace tp = thin_provisioning;
//----------------------------------------------------------------
namespace {
//------------------------------------------------
// XML generator
//------------------------------------------------
class xml_emitter : public emitter {
public:
xml_emitter(ostream &out)
: out_(out),
indent_(0) {
}
void begin_superblock(string const &uuid,
uint64_t time,
uint64_t trans_id,
uint32_t data_block_size,
uint64_t nr_data_blocks,
boost::optional<uint64_t> metadata_snap) {
indent();
out_ << "<superblock uuid=\"" << uuid << "\""
<< " time=\"" << time << "\""
<< " transaction=\"" << trans_id << "\""
<< " data_block_size=\"" << data_block_size << "\""
<< " nr_data_blocks=\"" << nr_data_blocks;
if (metadata_snap)
out_ << " metadata_snap=\"" << *metadata_snap;
out_ << "\">"
<< endl;
inc();
}
void end_superblock() {
dec();
indent();
out_ << "</superblock>" << endl;
}
void begin_device(uint32_t dev_id,
uint64_t mapped_blocks,
uint64_t trans_id,
uint64_t creation_time,
uint64_t snap_time) {
indent();
out_ << "<device dev_id=\"" << dev_id << "\""
<< " mapped_blocks=\"" << mapped_blocks << "\""
<< " transaction=\"" << trans_id << "\""
<< " creation_time=\"" << creation_time << "\""
<< " snap_time=\"" << snap_time << "\">" << endl;
inc();
}
void end_device() {
dec();
indent();
out_ << "</device>" << endl;
}
void begin_named_mapping(string const &name) {
indent();
out_ << "<named_mapping>" << endl;
inc();
}
void end_named_mapping() {
dec();
indent();
out_ << "</named_mapping>" << endl;
}
void identifier(string const &name) {
indent();
out_ << "<identifier name=\"" << name << "\"/>" << endl;
}
void range_map(uint64_t origin_begin, uint64_t data_begin, uint32_t time, uint64_t len) {
indent();
out_ << "<range_mapping origin_begin=\"" << origin_begin << "\""
<< " data_begin=\"" << data_begin << "\""
<< " length=\"" << len << "\""
<< " time=\"" << time << "\""
<< "/>" << endl;
}
void single_map(uint64_t origin_block, uint64_t data_block, uint32_t time) {
indent();
out_ << "<single_mapping origin_block=\"" << origin_block << "\""
<< " data_block=\"" << data_block << "\""
<< " time=\"" << time << "\""
<< "/>" << endl;
}
private:
void indent() {
for (unsigned i = 0; i < indent_ * 2; i++)
out_ << ' ';
}
void inc() {
indent_++;
}
void dec() {
indent_--;
}
ostream &out_;
unsigned indent_;
};
//------------------------------------------------
// XML parser
//------------------------------------------------
typedef std::map<string, string> attributes;
void build_attributes(attributes &a, char const **attr) {
while (*attr) {
char const *key = *attr;
attr++;
if (!*attr) {
ostringstream out;
out << "No value given for xml attribute: " << key;
throw runtime_error(out.str());
}
char const *value = *attr;
a.insert(make_pair(string(key), string(value)));
attr++;
}
}
template <typename T>
T get_attr(attributes const &attr, string const &key) {
attributes::const_iterator it = attr.find(key);
if (it == attr.end()) {
ostringstream out;
out << "could not find attribute: " << key;
throw runtime_error(out.str());
}
return boost::lexical_cast<T>(it->second);
}
template <typename T>
boost::optional<T> get_opt_attr(attributes const &attr, string const &key) {
typedef boost::optional<T> rtype;
attributes::const_iterator it = attr.find(key);
if (it == attr.end())
return rtype();
return rtype(boost::lexical_cast<T>(it->second));
}
void parse_superblock(emitter *e, attributes const &attr) {
e->begin_superblock(get_attr<string>(attr, "uuid"),
get_attr<uint64_t>(attr, "time"),
get_attr<uint64_t>(attr, "transaction"),
get_attr<uint32_t>(attr, "data_block_size"),
get_attr<uint64_t>(attr, "nr_data_blocks"),
get_opt_attr<uint64_t>(attr, "metadata_snap"));
}
void parse_device(emitter *e, attributes const &attr) {
e->begin_device(get_attr<uint32_t>(attr, "dev_id"),
get_attr<uint64_t>(attr, "mapped_blocks"),
get_attr<uint64_t>(attr, "transaction"),
get_attr<uint64_t>(attr, "creation_time"),
get_attr<uint64_t>(attr, "snap_time"));
}
void parse_range_mapping(emitter *e, attributes const &attr) {
e->range_map(get_attr<uint64_t>(attr, "origin_begin"),
get_attr<uint64_t>(attr, "data_begin"),
get_attr<uint32_t>(attr, "time"),
get_attr<uint64_t>(attr, "length"));
}
void parse_single_mapping(emitter *e, attributes const &attr) {
e->single_map(get_attr<uint64_t>(attr, "origin_block"),
get_attr<uint64_t>(attr, "data_block"),
get_attr<uint32_t>(attr, "time"));
}
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"))
parse_superblock(e, a);
else if (!strcmp(el, "device"))
parse_device(e, a);
else if (!strcmp(el, "range_mapping"))
parse_range_mapping(e, a);
else if (!strcmp(el, "single_mapping"))
parse_single_mapping(e, a);
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, "device"))
e->end_device();
else if (!strcmp(el, "range_mapping")) {
// do nothing
} else if (!strcmp(el, "single_mapping")) {
// do nothing
} else
throw runtime_error("unknown tag close");
}
}
//----------------------------------------------------------------
tp::emitter::ptr
tp::create_xml_emitter(ostream &out)
{
return emitter::ptr(new xml_emitter(out));
}
void
tp::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());
}
}
}
//----------------------------------------------------------------