examples/copydatabase.cc

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/* Copyright (C) 2006,2007,2008 Olly Betts
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <config.h>

#include <xapian.h>

#include <iomanip>
#include <iostream>

#include <cmath> // For log10().
#include <cstdlib> // For exit().
#include <cstring> // For strcmp() and strrchr().

using namespace std;

#define PROG_NAME "copydatabase"
#define PROG_DESC "Perform a document-by-document copy of one or more Xapian databases"

static void
show_usage(int rc)
{
    cout << "Usage: "PROG_NAME" SOURCE_DATABASE... DESTINATION_DATABASE\n\n"
"Options:\n"
"  --help           display this help and exit\n"
"  --version        output version information and exit" << endl;
    exit(rc);
}

int
main(int argc, char **argv)
try {
    if (argc > 1 && argv[1][0] == '-') {
        if (strcmp(argv[1], "--help") == 0) {
            cout << PROG_NAME" - "PROG_DESC"\n\n";
            show_usage(0);
        }
        if (strcmp(argv[1], "--version") == 0) {
            cout << PROG_NAME" - "PACKAGE_STRING << endl;
            exit(0);
        }
    }

    // We expect two or more arguments: at least one source database path
    // followed by the destination database path.
    if (argc < 3) show_usage(1);

    // Create the destination database, using DB_CREATE so that we don't
    // try to overwrite or update an existing database in case the user
    // got the command line argument order wrong.
    const char *dest = argv[argc - 1];
    Xapian::WritableDatabase db_out(dest, Xapian::DB_CREATE);

    for (int i = 1; i < argc - 1; ++i) {
        char * src = argv[i];
        if (*src) {
            // Remove any trailing directory separator.
            char & ch = src[strlen(src) - 1];
            if (ch == '/' || ch == '\\') ch = '\0';
        }

        // Open the source database.
        Xapian::Database db_in(src);

        // Find the leaf-name of the database path for reporting progress.
        const char * leaf = strrchr(src, '/');
#if defined __WIN32__ || defined __EMX__
        if (!leaf) leaf = strrchr(src, '\\');
#endif
        if (leaf) ++leaf; else leaf = src;

        // Iterate over all the documents in db_in, copying each to db_out.
        Xapian::doccount dbsize = db_in.get_doccount();
        if (dbsize == 0) {
            cout << leaf << ": empty!" << endl;
        } else {
            // Calculate how many decimal digits there are in dbsize.
            int width = static_cast<int>(log10(double(dbsize))) + 1;

            Xapian::doccount c = 0;
            Xapian::PostingIterator it = db_in.postlist_begin("");
            while (it != db_in.postlist_end("")) {
                db_out.add_document(db_in.get_document(*it));

                // Update for the first 10, and then every 13th document
                // counting back from the end (this means that all the
                // digits "rotate" and the counter ends up on the exact
                // total.
                ++c;
                if (c <= 10 || (dbsize - c) % 13 == 0) {
                    cout << '\r' << leaf << ": ";
                    cout << setw(width) << c << '/' << dbsize << flush;
                }

                ++it;
            }

            cout << endl;
        }

        cout << "Copying spelling data..." << flush;
        Xapian::TermIterator spellword = db_in.spellings_begin();
        while (spellword != db_in.spellings_end()) {
            db_out.add_spelling(*spellword, spellword.get_termfreq());
            ++spellword;
        }
        cout << " done." << endl;

        cout << "Copying synonym data..." << flush;
        Xapian::TermIterator synkey = db_in.synonym_keys_begin();
        while (synkey != db_in.synonym_keys_end()) {
            string key = *synkey;
            Xapian::TermIterator syn = db_in.synonyms_begin(key);
            while (syn != db_in.synonyms_end(key)) {
                db_out.add_synonym(key, *syn);
                ++syn;
            }
            ++synkey;
        }
        cout << " done." << endl;

        cout << "Copying user metadata..." << flush;
        Xapian::TermIterator metakey = db_in.metadata_keys_begin();
        while (metakey != db_in.metadata_keys_end()) {
            string key = *metakey;
            db_out.set_metadata(key, db_in.get_metadata(key));
            ++metakey;
        }
        cout << " done." << endl;
    }

    cout << "Flushing..." << flush;
    // Flush explicitly so that any error is reported.
    db_out.flush();
    cout << " done." << endl;
} catch (const Xapian::Error & e) {
    cerr << '\n' << argv[0] << ": " << e.get_description() << endl;
    exit(1);
}

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