concordia-library/concordia/concordia_index.cpp
2013-11-20 17:43:29 +01:00

92 lines
3.3 KiB
C++

#include "concordia/concordia_index.hpp"
#include <boost/filesystem.hpp>
ConcordiaIndex::ConcordiaIndex(const string & wordMapFilepath,
const string & hashedIndexFilepath,
const string & suffixArrayFilepath)
throw(ConcordiaException) {
if (boost::filesystem::exists(wordMapFilepath)) {
if (boost::filesystem::exists(hashedIndexFilepath)) {
_hashedIndexFile.open(hashedIndexFilepath.c_str(), ios::out |
ios::app | ios::binary);
if (!_hashedIndexFile.is_open()) {
throw ConcordiaException("E03: Failed to open hashed index "
"file for appending.");
}
} else {
throw ConcordiaException("E01: Word map file exists "
"but hashed index file absent.");
}
} else { // WordMap file does not exist
if (boost::filesystem::exists(hashedIndexFilepath)) {
throw ConcordiaException("E02: Hashed index file exists "
"but word map file absent.");
} else {
_hashedIndexFile.open(hashedIndexFilepath.c_str(), ios::out |
ios::binary);
if (!_hashedIndexFile.is_open()) {
throw ConcordiaException("E04: Failed to open hashed index "
"file for writing.");
}
}
}
_suffixArrayFile.open(suffixArrayFilepath.c_str(), ios::out |
ios::binary);
if (!_hashedIndexFile.is_open()) {
throw ConcordiaException("E05: Failed to open suffix array "
"file for writing.");
}
_hashGenerator = boost::shared_ptr<HashGenerator>(
new HashGenerator(wordMapFilepath));
}
ConcordiaIndex::~ConcordiaIndex() {
}
void ConcordiaIndex::serializeWordMap() {
_hashGenerator->serializeWordMap();
}
void ConcordiaIndex::generateSuffixArray() {
/* Get the file size. */
long n = _hashedIndexFile.tellg();
/* Allocate 5blocksize bytes of memory. */
sauchar_t *T;
saidx_t *SA;
T = reinterpret_cast<sauchar_t *> (malloc((size_t)n * sizeof(sauchar_t)));
SA = reinterpret_cast<saidx_t *> (malloc((size_t)n * sizeof(saidx_t)));
if ((T == NULL) || (SA == NULL)) {
throw ConcordiaException("Cannot allocate memory.");
}
/* Read n bytes of data. */
_hashedIndexFile.seekg(0, ios::beg);
_hashedIndexFile.read(reinterpret_cast<char*> (T), (size_t)n);
/* Construct the suffix array. */
if (divsufsort(T, SA, (saidx_t)n) != 0) {
throw ConcordiaException("Error creating suffix array.");
}
/* Write the suffix array. */
_suffixArrayFile << *SA;
/* Deallocate memory. */
free(SA);
free(T);
}
void ConcordiaIndex::addSentence(const string & sentence) {
vector<sauchar_t> hash = _hashGenerator->generateHash(sentence);
for (vector<sauchar_t>::iterator it = hash.begin();
it != hash.end(); ++it) {
_hashedIndexFile << *it;
}
}