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Diffstat (limited to 'ept/apt/recordparser.cc')
| -rw-r--r-- | ept/apt/recordparser.cc | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/ept/apt/recordparser.cc b/ept/apt/recordparser.cc new file mode 100644 index 0000000..3562123 --- /dev/null +++ b/ept/apt/recordparser.cc @@ -0,0 +1,170 @@ +/** \file + * Parser for APT records + */ + +/* + * Copyright (C) 2007 Enrico Zini <enrico@enricozini.org> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <ept/apt/recordparser.h> + +#include <algorithm> +#include <cctype> + +//#include <iostream> + +using namespace std; + +namespace ept { +namespace apt { + +struct rpcompare +{ + const RecordParser& rp; + rpcompare(const RecordParser& rp) : rp(rp) {} + bool operator()(size_t a, size_t b) + { + return rp.name(a) < rp.name(b); + } +}; + +void RecordParser::scan(const std::string& str) +{ + buffer = str; + ends.clear(); + sorted.clear(); + + //cerr << "PARSE " << endl << buffer << "*****" << endl; + + // Scan the buffer, taking note of all ending offsets of the various fields + size_t pos = 0; + size_t idx = 0; + while (pos < buffer.size() - 1) + { + //cerr << "PREPOS " << pos << " left: " << buffer.substr(pos, 10) << endl; + pos = buffer.find("\n", pos); + //cerr << "POSTPOS " << pos << " left: " << (pos == string::npos ? "NONE" : buffer.substr(pos, 10)) << endl; + + // The buffer does not end with a newline + if (pos == string::npos) + { + //cerr << "ENDNOTEOL" << endl; + pos = buffer.size(); + ends.push_back(pos); + sorted.push_back(idx++); + break; + } + + ++pos; + //cerr << "POSTPOSINC " << pos << " left: " << buffer.substr(pos, 10) << endl; + + // The buffer ends with a newline + if (pos == buffer.size()) + { + //cerr << "ENDEOL" << endl; + ends.push_back(pos); + sorted.push_back(idx++); + break; + } + + // Terminate parsing on double newlines + if (buffer[pos] == '\n') + { + //cerr << "ENDDOUBLENL" << endl; + ends.push_back(pos); + sorted.push_back(idx++); + break; + } + + // Mark the end of the field if it's not a continuation line + if (!isspace(buffer[pos])) + { + //cerr << "INNERFIELD" << endl; + ends.push_back(pos); + sorted.push_back(idx++); + } //else + //cerr << "CONTLINE" << endl; + } + + // Sort the sorted array + sort(sorted.begin(), sorted.end(), rpcompare(*this)); + + //for (size_t i = 0; i < ends.size(); ++i) + // cerr << ends[i] << "\t" << name(i) << "\t" << sorted[i] << "\t" << name(sorted[i]) << endl; +} + +std::string RecordParser::field(size_t idx) const +{ + if (idx >= ends.size()) + return string(); + if (idx == 0) + return buffer.substr(0, ends[0]); + else + return buffer.substr(ends[idx-1], ends[idx]-ends[idx-1]); +} + +std::string RecordParser::name(size_t idx) const +{ + string res = field(idx); + size_t pos = res.find(":"); + if (pos == string::npos) + return res; + return res.substr(0, pos); +} + +std::string RecordParser::lookup(size_t idx) const +{ + string res = field(idx); + size_t pos = res.find(":"); + if (pos == string::npos) + return res; + // Skip initial whitespace after the : + for (++pos; pos < res.size() && isspace(res[pos]); ++pos) + ; + res = res.substr(pos); + // Trim spaces at the end + while (!res.empty() && isspace(res[res.size() - 1])) + res.resize(res.size() - 1); + return res; +} + +size_t RecordParser::index(const std::string& str) const +{ + int begin, end; + + /* Binary search */ + begin = -1, end = size(); + while (end - begin > 1) + { + int cur = (end + begin) / 2; + //cerr << "Test " << cur << " " << str << " < " << name(cur) << endl; + if (name(sorted[cur]) > str) + end = cur; + else + begin = cur; + } + + if (begin == -1 || name(sorted[begin]) != str) + return size(); + else + return sorted[begin]; +} + +} +} + +// vim:set ts=4 sw=4: |