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arangodb/arangod/FulltextIndex/fulltext-query.cpp

314 lines
9.6 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief fulltext query functionality
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2012-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#include "fulltext-query.h"
#include "BasicsC/logging.h"
#include "Basics/tri-strings.h"
#include "BasicsC/utf8-helper.h"
#include "fulltext-index.h"
// -----------------------------------------------------------------------------
// --SECTION-- private functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief normalise a word for a fulltext search query
////////////////////////////////////////////////////////////////////////////////
static TRI_fulltext_query_operation_e ParseOperation (char c) {
if (c == '|') {
return TRI_FULLTEXT_OR;
}
else if (c == '-') {
return TRI_FULLTEXT_EXCLUDE;
}
// this is the default
return TRI_FULLTEXT_AND;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief normalise a word for a fulltext search query
/// this will create a copy of the word
////////////////////////////////////////////////////////////////////////////////
static char* NormaliseWord (char const* word,
size_t wordLength) {
// normalise string
size_t outLength;
char* copy = TRI_normalize_utf8_to_NFC(TRI_UNKNOWN_MEM_ZONE, word, wordLength, &outLength);
if (copy == nullptr) {
return nullptr;
}
// lower case string
int32_t outLength2;
char* copy2 = TRI_tolower_utf8(TRI_UNKNOWN_MEM_ZONE, copy, (int32_t) outLength, &outLength2);
TRI_Free(TRI_UNKNOWN_MEM_ZONE, copy);
if (copy2 == nullptr) {
return nullptr;
}
char* prefixEnd = TRI_PrefixUtf8String(copy2, TRI_FULLTEXT_MAX_WORD_LENGTH);
ptrdiff_t prefixLength = prefixEnd - copy2;
char* copy3 = static_cast<char*>(TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, sizeof(char) * ((size_t) prefixLength + 1), false));
if (copy3 == nullptr) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, copy2);
return nullptr;
}
memcpy(copy3, copy2, ((size_t) prefixLength) * sizeof(char));
copy3[prefixLength] = '\0';
TRI_Free(TRI_UNKNOWN_MEM_ZONE, copy2);
return copy3;
}
// -----------------------------------------------------------------------------
// --SECTION-- constructors / destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief create a fulltext query
////////////////////////////////////////////////////////////////////////////////
TRI_fulltext_query_t* TRI_CreateQueryFulltextIndex (size_t numWords) {
TRI_fulltext_query_t* query = static_cast<TRI_fulltext_query_t*>(TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, sizeof(TRI_fulltext_query_t), false));
if (query == nullptr) {
return nullptr;
}
// fill word vector with NULLs
query->_words = static_cast<char**>(TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, sizeof(char*) * numWords, true));
if (query->_words == nullptr) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query);
return nullptr;
}
query->_matches = static_cast<TRI_fulltext_query_match_e*>(TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, sizeof(TRI_fulltext_query_match_e) * numWords, false));
if (query->_matches == nullptr) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query->_words);
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query);
return nullptr;
}
query->_operations = static_cast<TRI_fulltext_query_operation_e*>(TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, sizeof(TRI_fulltext_query_operation_e) * numWords, false));
if (query->_operations == nullptr) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query->_matches);
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query->_words);
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query);
return nullptr;
}
query->_numWords = numWords;
return query;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief free a fulltext query
////////////////////////////////////////////////////////////////////////////////
void TRI_FreeQueryFulltextIndex (TRI_fulltext_query_t* query) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query->_operations);
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query->_matches);
for (size_t i = 0; i < query->_numWords; ++i) {
char* word = query->_words[i];
if (word != nullptr) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, word);
}
}
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query->_words);
TRI_Free(TRI_UNKNOWN_MEM_ZONE, query);
}
// -----------------------------------------------------------------------------
// --SECTION-- public functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief create a fulltext query from a query string
////////////////////////////////////////////////////////////////////////////////
int TRI_ParseQueryFulltextIndex (TRI_fulltext_query_t* query,
char const* queryString,
bool* isSubstringQuery) {
char* ptr;
size_t i;
*isSubstringQuery = false;
ptr = (char*) queryString;
if (*ptr == '\0') {
return TRI_ERROR_BAD_PARAMETER;
}
i = 0;
while (*ptr) {
char* start;
char* end;
char* split;
TRI_fulltext_query_operation_e operation;
TRI_fulltext_query_match_e match;
char c;
c = *ptr;
// ignore whitespace
if (c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == '\f' || c == '\b' || c == ',') {
++ptr;
continue;
}
// defaults
operation = TRI_FULLTEXT_AND;
match = TRI_FULLTEXT_COMPLETE;
// word begin
// get operation
if (c == '+' || c == '-' || c == '|') {
operation = ParseOperation(c);
++ptr;
}
split = nullptr;
start = ptr;
while (*ptr) {
c = *ptr;
if (c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == '\f' || c == '\b' || c == ',') {
// end of word
break;
}
else if (split == nullptr && c == ':') {
split = ptr + 1;
}
++ptr;
}
end = ptr;
if ((end - start == 0) ||
(split != nullptr && split - start == 0) ||
(split != nullptr && end - split == 0)) {
// invalid string
return TRI_ERROR_BAD_PARAMETER;
}
// get command
if (split != nullptr) {
if (TRI_CaseEqualString2(start, "prefix:", strlen("prefix:"))) {
match = TRI_FULLTEXT_PREFIX;
}
// 2013-01-17: deactivated substring matching as there is no implementation for it
// else if (TRI_CaseEqualString2(start, "substring:", strlen("substring:"))) {
// match = TRI_FULLTEXT_SUBSTRING;
// }
else if (TRI_CaseEqualString2(start, "complete:", strlen("complete:"))) {
match = TRI_FULLTEXT_COMPLETE;
}
start = split;
}
TRI_ASSERT(end >= start);
if (! TRI_SetQueryFulltextIndex(query, (size_t) i, start, (size_t) (end - start), match, operation)) {
// normalisation failed
return TRI_ERROR_OUT_OF_MEMORY;
}
++i;
if (i >= TRI_FULLTEXT_SEARCH_MAX_WORDS) {
break;
}
}
if (i == 0) {
// no words to search...
return TRI_ERROR_BAD_PARAMETER;
}
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief set a search word & option for a query
/// the query will take ownership of the search word
////////////////////////////////////////////////////////////////////////////////
bool TRI_SetQueryFulltextIndex (TRI_fulltext_query_t* query,
size_t position,
char const* word,
size_t wordLength,
TRI_fulltext_query_match_e match,
TRI_fulltext_query_operation_e operation) {
char* normalised;
if (position >= query->_numWords) {
return false;
}
normalised = NormaliseWord(word, wordLength);
if (normalised == nullptr) {
query->_words[position] = nullptr;
return false;
}
query->_words[position] = normalised;
query->_matches[position] = match;
query->_operations[position] = operation;
return true;
}
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
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