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/*
* Copyright (C) 2012 Mikkel Kamstrup Erlandsen
*
* 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, see <http://www.gnu.org/licenses/>.
*
* Authored by Mikkel Kamstrup Erlandsen <mikkel.kamstrup@gmail.com>
*
*/
#include <string>
#include "stringutils.h"
#ifdef HAVE_DEE_ICU
#include <dee-icu.h>
#endif
using namespace std;
namespace ZeitgeistFTS {
namespace StringUtils {
/**
* Make sure s has equal or less than 'nbytes' bytes making sure the returned
* string is still valid UTF-8.
*
* NOTE: It is assumed the input string is valid UTF-8. Untrusted text
* should be validated with g_utf8_validate().
*
* This function useful for working with Xapian terms because Xapian has
* a max term length of 245 (which is not very well documented, but see
* http://xapian.org/docs/omega/termprefixes.html).
*/
string Truncate (string const& s, unsigned int nbytes)
{
const gchar *str = s.c_str();
const gchar *iter = str;
nbytes = MIN(nbytes, s.length());
while (iter - str < nbytes)
{
const gchar *tmp = g_utf8_next_char (iter);
if (tmp - str > nbytes) break;
iter = tmp;
}
return s.substr(0, iter - str);
}
/**
* Converts a URI into an index- and query friendly string. The problem
* is that Xapian doesn't handle CAPITAL letters or most non-alphanumeric
* symbols in a boolean term when it does prefix matching. The mangled
* URIs returned from this function are suitable for boolean prefix searches.
*
* IMPORTANT: This is a 1-way function! You can not convert back.
*/
string MangleUri (string const& orig)
{
string s(orig);
size_t pos = 0;
while ((pos = s.find_first_of (": /", pos)) != string::npos)
{
s.replace (pos, 1, 1, '_');
pos++;
}
return s;
}
/**
* This method expects a valid uri and tries to split it into authority,
* path and query.
*
* Note that any and all parts may be left untouched.
*/
void SplitUri (string const& uri, string &authority,
string &path, string &query)
{
size_t colon_pos = uri.find (':');
if (colon_pos == string::npos) return; // not an uri?
bool has_double_slash = uri.length () > colon_pos + 2 &&
uri.compare (colon_pos + 1, 2, "//") == 0;
size_t start_pos = has_double_slash ? colon_pos + 3 : colon_pos + 1;
size_t first_slash = uri.find ('/', start_pos);
size_t question_mark_pos = uri.find ('?', first_slash == string::npos ?
start_pos : first_slash + 1);
authority = uri.substr (start_pos);
if (first_slash != string::npos)
{
authority.resize (first_slash - start_pos);
}
else if (question_mark_pos != string::npos)
{
authority.resize (question_mark_pos - start_pos);
}
if (first_slash == string::npos)
{
first_slash = start_pos + authority.length ();
}
if (question_mark_pos != string::npos)
{
path = uri.substr (first_slash, question_mark_pos - first_slash);
query = uri.substr (question_mark_pos + 1);
}
else
{
path = uri.substr (first_slash);
}
}
#ifdef HAVE_DEE_ICU
static DeeICUTermFilter *icu_filter = NULL;
/**
* Use ascii folding filter on the input text and return folded version
* of the original string.
*
* Note that if the folded version is exactly the same as the original
* empty string will be returned.
*/
string AsciiFold (string const& input)
{
if (icu_filter == NULL)
{
icu_filter = dee_icu_term_filter_new_ascii_folder ();
if (icu_filter == NULL) return "";
}
// FIXME: check first if the input contains any non-ascii chars?
gchar *folded = dee_icu_term_filter_apply (icu_filter, input.c_str ());
string result (folded);
g_free (folded);
return result == input ? "" : result;
}
#else
string AsciiFold (string const& input)
{
return "";
}
#endif
} /* namespace StringUtils */
} /* namespace ZeitgeistFTS */
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