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#include <sstream>
#include <iostream>
#include <set>
#include "contexts_corpus.hh"
#include "gzstream.hh"
#include "contexts_lexer.h"
#include <boost/tuple/tuple.hpp>
using namespace std;
//////////////////////////////////////////////////
// ContextsCorpus
//////////////////////////////////////////////////
void read_callback(const ContextsLexer::PhraseContextsType& new_contexts, void* extra) {
assert(new_contexts.contexts.size() == new_contexts.counts.size());
boost::tuple<ContextsCorpus*, BackoffGenerator*, map<string,int>* >* extra_pair
= static_cast< boost::tuple<ContextsCorpus*, BackoffGenerator*, map<string,int>* >* >(extra);
ContextsCorpus* corpus_ptr = extra_pair->get<0>();
BackoffGenerator* backoff_gen = extra_pair->get<1>();
map<string,int>* counts = extra_pair->get<2>();
Document* doc(new Document());
//cout << "READ: " << new_contexts.phrase << "\t";
for (int i=0; i < new_contexts.contexts.size(); ++i) {
int cache_word_count = corpus_ptr->m_dict.max();
string context_str = corpus_ptr->m_dict.toString(new_contexts.contexts[i]);
// filter out singleton contexts
if (!counts->empty()) {
map<string,int>::const_iterator find_it = counts->find(context_str);
if (find_it == counts->end() || find_it->second < 2)
continue;
}
WordID id = corpus_ptr->m_dict.Convert(context_str);
if (cache_word_count != corpus_ptr->m_dict.max()) {
corpus_ptr->m_backoff->terms_at_level(0)++;
corpus_ptr->m_num_types++;
}
int count = new_contexts.counts[i];
for (int j=0; j<count; ++j)
doc->push_back(id);
corpus_ptr->m_num_terms += count;
// generate the backoff map
if (backoff_gen) {
int order = 1;
WordID backoff_id = id;
ContextsLexer::Context backedoff_context = new_contexts.contexts[i];
while (true) {
if (!corpus_ptr->m_backoff->has_backoff(backoff_id)) {
//cerr << "Backing off from " << corpus_ptr->m_dict.Convert(backoff_id) << " to ";
backedoff_context = (*backoff_gen)(backedoff_context);
if (backedoff_context.empty()) {
//cerr << "Nothing." << endl;
(*corpus_ptr->m_backoff)[backoff_id] = -1;
break;
}
if (++order > corpus_ptr->m_backoff->order())
corpus_ptr->m_backoff->order(order);
int cache_word_count = corpus_ptr->m_dict.max();
int new_backoff_id = corpus_ptr->m_dict.Convert(backedoff_context);
if (cache_word_count != corpus_ptr->m_dict.max())
corpus_ptr->m_backoff->terms_at_level(order-1)++;
//cerr << corpus_ptr->m_dict.Convert(new_backoff_id) << " ." << endl;
backoff_id = ((*corpus_ptr->m_backoff)[backoff_id] = new_backoff_id);
}
else break;
}
}
//cout << context_str << " (" << id << ") ||| C=" << count << " ||| ";
}
//cout << endl;
if (!doc->empty()) {
corpus_ptr->m_documents.push_back(doc);
corpus_ptr->m_keys.push_back(new_contexts.phrase);
}
}
void filter_callback(const ContextsLexer::PhraseContextsType& new_contexts, void* extra) {
assert(new_contexts.contexts.size() == new_contexts.counts.size());
map<string,int>* context_counts = (static_cast<map<string,int>*>(extra));
for (int i=0; i < new_contexts.contexts.size(); ++i) {
int count = new_contexts.counts[i];
pair<map<string,int>::iterator,bool> result
= context_counts->insert(make_pair(Dict::toString(new_contexts.contexts[i]),count));
if (!result.second)
result.first->second += count;
}
}
unsigned ContextsCorpus::read_contexts(const string &filename,
BackoffGenerator* backoff_gen_ptr,
bool filter_singeltons) {
map<string,int> counts;
if (filter_singeltons) {
cerr << "--- Filtering singleton contexts ---" << endl;
igzstream in(filename.c_str());
ContextsLexer::ReadContexts(&in, filter_callback, &counts);
}
m_num_terms = 0;
m_num_types = 0;
igzstream in(filename.c_str());
boost::tuple<ContextsCorpus*, BackoffGenerator*, map<string,int>* > extra_pair(this,backoff_gen_ptr,&counts);
ContextsLexer::ReadContexts(&in, read_callback, &extra_pair);
//m_num_types = m_dict.max();
cerr << "Read backoff with order " << m_backoff->order() << "\n";
for (int o=0; o<m_backoff->order(); o++)
cerr << " Terms at " << o << " = " << m_backoff->terms_at_level(o) << endl;
cerr << endl;
return m_documents.size();
}
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