ngrammar_io.cc

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/*                Centre for Speech Technology Research                  */
/*                     University of Edinburgh, UK                       */
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/*                     Author :  Simon King & Alan W Black               */
/*                     Date   :  February 1997                           */
/*-----------------------------------------------------------------------*/
/*                                                                       */
/* IO functions for EST_Ngram class                                      */
/*                                                                       */
/*=======================================================================*/

#include <cstdlib>
#include <fstream>
#include <iostream>
#include "EST_unix.h"
#include <cstring>
#include <climits>
#include <cfloat>
#include "EST_String.h"
#include "EST_Ngrammar.h"
#include "EST_Token.h"
#include "EST_cutils.h"
#include "EST_File.h"


using namespace std;

EST_read_status
load_ngram_htk_ascii(const EST_String filename, EST_Ngrammar &n)
{
    (void)filename;
    (void)n;
    return wrong_format;
}

EST_read_status
load_ngram_htk_binary(const EST_String filename, EST_Ngrammar &n)
{
    (void)filename;
    (void)n;
    return wrong_format;
}

EST_read_status
load_ngram_arpa(const EST_String filename, EST_Ngrammar &n, const EST_StrList &vocab)
{

    EST_TokenStream ts;
    EST_String s;
    int i,j,k, order=0;
    //double weight;
    /*double occur;*/
    int this_num,this_order;

    if (ts.open(filename) == -1)
    return misc_read_error;

    // find  backslash data backslash
    while ((!ts.eof()) && !ts.get().string().contains("\\data\\"));

    if (ts.eof())
    {
    ts.close();
    return wrong_format;
    }

    // find order and numbers of ngrams

    // somewhere to keep numbers
    EST_IVector nums(100); // not going to have anything bigger than a 100-gram !

    while (!ts.eof())
    {
    // have we got to next section
    if (ts.peek().string().contains("-grams:"))
        break;

    s=ts.get_upto_eoln().string();

    if(s.contains("ngram ") && s.contains("="))
    {

        s=s.after("ngram ");
        this_order=atoi(s.before("="));
        this_num=atoi(s.after("="));

        //cerr << "There are " << this_num << " " << this_order
        //<< "-grams" << endl;

        nums[this_order] = this_num;

        if(this_order > order)
        order = this_order;
    }

    }


    if(order==0)
    {
    //cerr << "No ngram ?=? in header !" << endl;
    ts.close();
    return wrong_format;
    }

    //cerr << "Initialising " << order << "-grammar" << endl;
    if(!n.init(order,EST_Ngrammar::backoff,vocab))
    return misc_read_error;

    // read data
    for(i=1;i<=order;i++)
    {

    EST_StrVector window(i);

    // find start of data for this order "<order>-grams:"
    EST_String tmp =  "\\" + itoString(i) + "-grams:";
    while (!ts.eof())
    {
        s=ts.get().string();
        if (s.contains(tmp))
        break;
    }


    if(ts.eof())
    {
        cerr << "Unexpected end of grammar file whilst looking for '"
        << tmp << "'" << endl;
        return misc_read_error;
    }
    
    //cerr << "Found order " << i << " : " << tmp << endl;
    //cerr << "Looking for " << nums(i) << " ngrams" << endl;
    // look for nums(i) ngrams

    for(j=0;j<nums(i);j++)
    {
        
        for (k=0; ((k<i) && !ts.eof()); k++)
        window[k] = ts.get().string();

        if(ts.eof())
        {
        cerr << "Unexpected end of file whilst reading " << i
            << "-grams !" << endl;
        return misc_read_error;
        }

        /*occur = atof(ts.get().string()); unused*/
        ts.get().string();

        // can't for backoff grammars, need to set probs directly
        
        cerr << "ooooooooops" << endl;
        return wrong_format;
        /* BEGIN COMMENT: This code is unreachable
        //n.accumulate(window,occur);

        // backoff weight ?
        if (!ts.eoln())
        {
        weight = atof(ts.get().string());
        n.set_backoff_weight(window,weight);
        }
        
        if (!ts.eoln())
        {
        cerr << "EST_Ngrammar:load_ngram_arpa expect end of line at filepos "
            << ts.filepos() << endl;
        ts.close();
        return misc_read_error;
        }
        END COMMENT: This code is unreachable */

    }
    
    } // loop through orders
    

    // find backslash end backslash 
    while (!ts.eof())
    if (ts.get().string() == "\\end\\")
    {
        ts.close();
        return format_ok;

    }

    cerr << "Missing \\end\\ !" << endl;

    ts.close();
    return misc_read_error;

}

EST_read_status
load_ngram_cstr_ascii(const EST_String filename, EST_Ngrammar &n)
{
    EST_TokenStream ts;
    int i, order;
    double occur;
    
    if (ts.open(filename) == -1)
    return misc_read_error;

    if (ts.peek().string() != "Ngram_2")
    {
    ts.close();
    return wrong_format;
    }
    ts.get();           // skip magic number
    
    order = atoi(ts.get().string());
    ts.get_upto_eoln();     // skip to next line
    EST_StrList vocab;
    EST_StrList pred_vocab; // may be different
    
    while (!ts.eoln())
    vocab.append(ts.get().string());
    ts.get_upto_eoln();     // skip to next line
    while (!ts.eoln())
    pred_vocab.append(ts.get().string());
    
    if(!n.init(order,EST_Ngrammar::dense,vocab,pred_vocab))
    {
    cerr << "Something may be wrong with the vocab lists in '"
        << filename << "'" << endl;
    return misc_read_error;
    }
    
    EST_StrVector window(order);
    
    while(!ts.eof())
    {
    for (i=0; i < order; i++)
        window[i] = ts.get().string();
    if (ts.get().string() != ":")
    {
        cerr << "EST_Ngrammar:load_ngram_cstr_ascii missing colon at filepos "
        << ts.filepos() << endl;
        return misc_read_error;
    }
    occur = atof(ts.get().string());
    n.accumulate(window,occur);
    if (!ts.eoln())
    {
        cerr << "EST_Ngrammar:load_ngram_cstr_ascii expect end of line at filepos "
        << ts.filepos() << endl;
        return misc_read_error;
    }
    }
    
    ts.close();
    
    return format_ok;
}

EST_read_status 
load_ngram_cstr_bin(const EST_String filename, EST_Ngrammar &n)
{
    EST_TokenStream ts;
    int i,j,order;
    EST_Litem *k;
    int num_entries;
    double approx_num_samples = 0.0;
    long freq_data_start, freq_data_end;
    FILE *ifd;
    int magic = 0;
    int swap = FALSE;
    
    if ((ifd=fopen(filename,"rb")) == NULL)
    return misc_read_error;
    if (fread(&magic,sizeof(int),1,ifd) != 1)
    {
        cerr << "Could not read integer from " << filename << endl;
        fclose(ifd);
        return misc_read_error;
    }
    if (SWAPINT(magic) == EST_NGRAMBIN_MAGIC)
    swap = TRUE;
    else if (magic != EST_NGRAMBIN_MAGIC) {
        fclose(ifd);
        return wrong_format;
    }
    if (ts.open(ifd, FALSE) == -1)
    return misc_read_error;
    
    ts.set_SingleCharSymbols("\n");
    ts.set_WhiteSpaceChars(" \t\r");
    
    if (ts.peek().string() != "mBin_2")
    {
    fclose(ifd);
    ts.close();
    return wrong_format;
    }
    ts.get();           // skip magic number
    
    order = atoi(ts.get().string());
    if (ts.get() != "\n")
    {
    fclose(ifd);
    ts.close();
    return misc_read_error;
    }
    EST_StrList vocab;
    EST_StrList pred_vocab; // may be different
    
    while ((ts.peek() != "\n") && (!ts.eof()))
    vocab.append(ts.get().string());
    ts.get();           // skip newline
    while ((ts.peek() != "\n") && (!ts.eof()))
    pred_vocab.append(ts.get().string());
    
    // Need to get to the position one after the newline and
    // who knows what TokenStream has already read,
    EST_fseek(ifd,(long)(ts.peek().filepos()+5),SEEK_SET);
    
    if(!n.init(order,EST_Ngrammar::dense,vocab,pred_vocab))
    {
    ts.close();
    fclose(ifd);
    return misc_read_error;
    }
    
    EST_StrVector window(order);
    
    freq_data_start = EST_ftell(ifd);
    EST_fseek(ifd,0,SEEK_END);
    freq_data_end = EST_ftell(ifd);
    num_entries = (freq_data_end-freq_data_start)/sizeof(double);
    double *dd = new double[num_entries];
    
    // Go back to start of data
    EST_fseek(ifd,freq_data_start,SEEK_SET);
    
    if (fread(dd,sizeof(double),num_entries,ifd) != (unsigned)num_entries)
    {
    cerr << "EST_Ngrammar::load_ngram_cstr_bin format does not have expected number of entries" << endl;
    ts.close();
    fclose(ifd);
    delete[] dd;
    return misc_read_error;
    }
    if (swap)
    swap_bytes_double(dd,num_entries);
    
    for(j=i=0;i<n.num_states();i++)
    {
    if (j >= num_entries)
    {
        cerr << "EST_Ngrammar::load_ngram_cstr_bin unexpected end of frequency data" << endl;
        ts.close();
        fclose(ifd);
        delete[] dd;
        return misc_read_error; 
    }
    for (k=n.p_states[i].pdf().item_start();
         (!n.p_states[i].pdf().item_end(k)) && (j < num_entries) ;
         k = n.p_states[i].pdf().item_next(k))
    {
        n.p_states[i].pdf().set_frequency(k,dd[j]);
        // Update global info too
        approx_num_samples += dd[j]; // probably not right
        n.vocab_pdf.cumulate(k,dd[j]);
        
        // Number of consecutive occurrences of this frequency as in
        // dd[j+1] if its a negative number
        if (j+1 >= num_entries)
        j++;
        else if (dd[j+1] < -1)
        dd[j+1]++;
        else if (dd[j+1] == -1)
        j +=2;
        else
        j++;
    }
    }
    
    // With smoothing num_samples might not be as exact as you like
    n.p_num_samples = (int)approx_num_samples;
    
    delete [] dd;
    
    ts.close();
    fclose(ifd);
    
    return format_ok;
}

// ====================================================================

EST_write_status
save_ngram_htk_ascii_sub(const EST_String &word, ostream *ost, 
             EST_Ngrammar &n, double floor)
{
    EST_Litem *k;
    EST_String name;
    double freq;
    EST_StrVector this_ngram(2); // assumes bigram
    this_ngram[0] = word;
    EST_DiscreteProbDistribution this_pdf;
    this_pdf = n.prob_dist(this_ngram);
    
    double lfreq=-1;
    int lcount=0;
    double total_freq=0;
    
    double floor_prob_total = floor * (n.pred_vocab->length()-1);
    
    if (word == n.p_sentence_end_marker)
    {
    *ost << word;
    *ost << " 0*" << n.pred_vocab->length()-1 << " " << 1 << endl;
    return write_ok;
    }
    
    if(floor_prob_total > 1)
    {
    cerr << "ERROR : floor is impossibly large, scaling it !" << endl;
    floor = 1.0 / (double)(n.pred_vocab->length()-1);
    floor_prob_total = 1;
    }
    
    // not efficient but who cares ?
    for (k=this_pdf.item_start();
     !this_pdf.item_end(k);
     k = this_pdf.item_next(k))
    {
    this_pdf.item_freq(k,name,freq);
    if(name != n.p_sentence_start_marker)
    {
        total_freq += freq;
    }
    }
    
    
    // 0 for prob(word,start marker)
    *ost << word << " 0 ";
    
    if (total_freq <= 0)
    {
    *ost << 1.0 / (double)(n.pred_vocab->length()-1) << "*";
    *ost << n.pred_vocab->length()-1 << " " << endl;
    }
    else
    {
    lfreq=-1;
    
    for (k=this_pdf.item_start();
         !this_pdf.item_end(k);
         k = this_pdf.item_next(k))
    {
        this_pdf.item_freq(k,name,freq);
        
        if ( (name == n.p_sentence_start_marker) ||
        (name == n.p_sentence_end_marker) ||
        (name == OOV_MARKER) )
        continue;
        
        if (freq == lfreq)
        lcount++;
        else
        {
        if (lcount > 1)
            *ost << "*" << lcount << " ";
        else
            *ost << " ";
        
        lcount=1;
        lfreq = freq;
        
        if(freq > 0)
        {
            double base_prob = freq / total_freq;
            
            // and floor/scale it
            *ost << floor + ( base_prob * (1-floor_prob_total) );
            
        }
        else
            *ost << floor;
        
        }
        
        
    }
    
    }               // total_freq > 0
    
    
    if(!n.closed_vocab())
    {
    
    // not fully tested !!!!!!!!
    
    *ost << 0 << " ERROR !!!!!!!! ";
    }
    
    
    if (total_freq > 0)
    {
    freq = this_pdf.frequency(n.p_sentence_end_marker);
    
    if(freq == lfreq)
    {
        lcount++;
        *ost << "*" << lcount << " " << endl;
    }
    else
    {
        
        if (lcount > 1)
        *ost << "*" << lcount << " ";
        else
        *ost << " ";
        
        if(freq > 0)
        {
        double base_prob = freq / total_freq;
        
        // and floor/scale it
        *ost << floor + ( base_prob * (1-floor_prob_total) ) << endl;
        
        }
        else
        *ost << floor << endl;
    }
    }
    
    return write_ok;
}

EST_write_status
save_ngram_htk_ascii(const EST_String filename, 
             EST_Ngrammar &n, double floor)
{
    
    ostream *ost;

    // only for bigram
    if(n.order() != 2)
    {
    cerr << "Can only save bigrams in htk_ascii format" << endl;
    return misc_write_error;
    }
    
    if (floor < 0)
    {
    cerr << "Negative floor probability does not make sense !" << endl;
    return misc_write_error;
    }
    
    if (filename == "-")
    ost = &cout;
    else
    ost = new ofstream(filename);
    
    if(!(*ost))
    return write_fail;
    
    if(floor * (n.pred_vocab->length()-1) > 1)
    {
    floor = 1.0 / (double)(n.pred_vocab->length()-1);
    cerr << "ERROR : floor is impossibly large, scaling it to ";
    cerr << floor << endl;
    }
    
    int i;
    
    if(n.p_sentence_start_marker == "")
    {
    cerr << "Can't save in HTK format as no sentence start/end tags"
        << " were given !" << endl;
    return misc_write_error;
    }
    
    // need '!ENTER' (or whatever) as first word- that's HTK for you
    save_ngram_htk_ascii_sub(n.p_sentence_start_marker,ost,n,floor);
    
    // the real words
    for(i=0;i<n.vocab->length();i++)
    {
    if ( (n.vocab->name(i) != n.p_sentence_start_marker) &&
        (n.vocab->name(i) != n.p_sentence_end_marker) &&
        (n.vocab->name(i) != OOV_MARKER) )
        save_ngram_htk_ascii_sub(n.vocab->name(i),ost,n,floor);
    }
    
    if(!n.closed_vocab())
    save_ngram_htk_ascii_sub(OOV_MARKER,ost,n,floor);
    
    save_ngram_htk_ascii_sub(n.p_sentence_end_marker,ost,n,floor);
    
    if(ost != &cout)
    delete ost;
    
    return write_ok;
}

/*
   EST_write_status
   save_ngram_htk_binary(const EST_String filename, EST_Ngrammar &n)
   {
   return write_ok;
   }
   */

void
count_ngram_arpa_sub(EST_Ngrammar *n, EST_StrVector &ngram, void *count)
{
    if(n->ngram_exists(ngram))
    *((double*)count) += 1;
}

void
save_ngram_arpa_sub(EST_Ngrammar *n, EST_StrVector &ngram, void *ost)
{
    
    int i;
    
    if(n->ngram_exists(ngram))
    {
    *((ostream*)(ost)) << safe_log10(n->probability(ngram)) << " ";
    for(i=0;i<ngram.n();i++)
        *((ostream*)(ost)) << ngram(i) << " ";
    
    if ((n->representation() == EST_Ngrammar::backoff) &&
        (n->order() > ngram.n()) )
        *((ostream*)(ost)) << safe_log10(n->get_backoff_weight(ngram));
    //<< " = "
    //<< n->get_backoff_weight(ngram) << " ";
    
    *((ostream*)(ost)) << endl;
    
    }
}

EST_write_status
save_ngram_arpa(const EST_String filename, EST_Ngrammar &n)
{
    // ARPA MIT-LL format - see HTK manual !!
    
    ostream *ost;
    int i,o;
    /*int num_n;*/
    if (filename == "-")
    ost = &cout;
    else
    ost = new ofstream(filename);
    
    if (!(*ost))
    return write_fail;
    
    //n.set_entry_type(EST_Ngrammar::probabilities);
    //n.make_htk_compatible(); // fix enter/exit probs
    //*ost << *(n.vocab) << endl;
    
    // count number of ngrams
    /*num_n = (int)n.samples();*/
    *ost << "\\data\\" << endl;
    
    double *count = new double;
    
    if (n.representation() == EST_Ngrammar::backoff)
    {
    for(o=1;o<=n.order();o++)
    {
        EST_StrVector ngram(o);
        for(i=0;i<o;i++)
        ngram[i] = "";
        *count =0;
        
        // this is a deeply silly way to count them,
        // we could traverse the tree directly !
        n.iterate(ngram,&count_ngram_arpa_sub,(void*)count);
        *ost << "ngram " << o << "=" << *count << endl;
    }
    
    for(o=1;o<=n.order();o++)
    {
        *ost << endl;
        *ost << "\\" << o << "-grams:" << endl;
        EST_StrVector ngram(o);
        for(i=0;i<o;i++)
        ngram[i] = "";
        n.iterate(ngram,&save_ngram_arpa_sub,(void*)ost);
    }
    
    }
    else
    {
    EST_StrVector ngram(n.order());
    for(i=0;i<n.order();i++)
        ngram[i] = "";
    *count =0;
    n.iterate(ngram,&count_ngram_arpa_sub,(void*)count);
    *ost << "ngram " << n.order() << "=" << *count << endl;
    
    *ost << endl;
    *ost << "\\" << n.order() << "-grams:" << endl;
    
    for(i=0;i<n.order();i++)
        ngram[i] = "";
    n.iterate(ngram,&save_ngram_arpa_sub,ost);
    
    }
    
    *ost << "\\end\\" << endl;
    
    if (ost != &cout) delete ost;
    delete count;
    return write_ok;
}

EST_write_status 
save_ngram_cstr_ascii(const EST_String filename, EST_Ngrammar &n,
              const bool trace, double floor)
{
    // awb's format
    (void)trace;
    ostream *ost;
    int i;
    EST_Litem *k;
    
    if (filename == "-")
    ost = &cout;
    else
    ost = new ofstream(filename);
    
    if(!(*ost))
    return write_fail;
    
    *ost << "Ngram_2 " << n.order() << endl;
    for (i=0; i < n.vocab->length(); i++)
    *ost << n.vocab->name(i) << " ";
    *ost << endl;
    for (i=0; i < n.pred_vocab->length(); i++)
    *ost << n.pred_vocab->name(i) << " ";
    *ost << endl;
    
    if (n.representation() == EST_Ngrammar::dense)
    n.print_freqs(*ost,floor);
    else if (n.representation() == EST_Ngrammar::backoff)
    {
      int total_ngrams = (int)pow(float(n.get_vocab_length()),float(n.order()-1));
    
    for(i=0;i<total_ngrams;i++)
    {
        EST_DiscreteProbDistribution this_pdf;
        const EST_StrVector this_ngram = n.make_ngram_from_index(i);
        this_pdf = n.prob_dist(this_ngram);
        
        for (k=this_pdf.item_start();
         !this_pdf.item_end(k);
         k = this_pdf.item_next(k))
        {
        double freq;
        EST_String name;
        this_pdf.item_freq(k,name,freq);
        
        for (int jj=0; jj < this_ngram.n(); jj++)
            *ost << this_ngram(jj) << " ";
        *ost << name << " : " << freq << endl;
        }
    }
    }
    
    if(ost != &cout)
    delete ost;
    
    return write_ok;
}

EST_write_status 
save_ngram_wfst(const EST_String filename, EST_Ngrammar &n)
{
    // Save as a WFST
    FILE *ost;
    int i;

    if ((ost = fopen(filename,"wb")) == NULL)
    {
    cerr << "Ngrammar save: unable to open \"" << filename << 
        "\" for writing" << endl;
    return write_fail;
    }

    fprintf(ost,"EST_File fst\n");
    fprintf(ost,"DataType ascii\n");
    fprintf(ost,"in \"(");
    for (i=0; i < n.vocab->length(); i++)
    fprintf(ost," %s\n",(const char *)n.vocab->name(i));
    fprintf(ost," )\"\n");
    fprintf(ost,"out \"(");
    for (i=0; i < n.vocab->length(); i++)
    fprintf(ost," %s\n",(const char *)n.vocab->name(i));
    fprintf(ost," )\"\n");
    fprintf(ost,"NumStates %d\n",n.num_states());
    fprintf(ost,"EST_Header_End\n");

    for (i=0; i<n.num_states(); i++)
    {
    fprintf(ost,"((%d nonfinal %d)\n",i,i);
    fprintf(ost,")\n");
    }

    fclose(ost);
    
    return write_ok;
}

EST_write_status 
save_ngram_cstr_bin(const EST_String filename, EST_Ngrammar &n, 
            const bool trace, double floor)
{
    
    if (n.representation() == EST_Ngrammar::sparse)
    return misc_write_error;
    
    int i;
    EST_Litem *k;
    FILE *ofd;
    double lfreq = -1;
    double count = -1;
    int magic = EST_NGRAMBIN_MAGIC;
    
    if (filename == "-")
    {
    if ((ofd=stdout) == NULL)
        return misc_write_error;
    }
    else
    {
    if ((ofd=fopen(filename,"wb")) == NULL)
        return misc_write_error;
    }
    
    fwrite(&magic,sizeof(int),1,ofd);
    fprintf(ofd,"mBin_2 %d\n",n.order());
    for (i=0; i < n.vocab->length(); i++)
    fprintf(ofd,"%s ",(const char *)n.vocab->name(i));
    fprintf(ofd,"\n");
    for (i=0; i < n.pred_vocab->length(); i++)
    fprintf(ofd,"%s ",(const char *)n.pred_vocab->name(i));
    fprintf(ofd,"\n");
    
    // We use a simple form of run-length encoding, if consecutive
    // values are equal only a length is printed.  lengths are
    // negative as frequencies (even smoothed ones) can never be -ve
    
    if ( trace )
    cerr << "Saving ..." << endl;
    
    if (n.representation() == EST_Ngrammar::dense)
    {
    for(i=0;i<n.num_states();i++)
    {
        
        if ( trace )
        cerr << "\r" << i*100/n.num_states() << "%";
        
        for (k=n.p_states[i].pdf().item_start();
         !n.p_states[i].pdf().item_end(k);
         k = n.p_states[i].pdf().item_next(k))
        {
        double freq;
        EST_String name;
        n.p_states[i].pdf().item_freq(k,name,freq);
        if (freq == 0.0)
            freq = floor;
        if (freq == lfreq)
            count--;
        else
        {
            if (count < -1)
            fwrite(&count,sizeof(double),1,ofd);
            fwrite(&freq,sizeof(double),1,ofd);
            count = -1;
        }
        lfreq = freq;
        }
    }
    if (count < -1)
        fwrite(&count,sizeof(double),1,ofd);
    }
    else if (n.representation() == EST_Ngrammar::backoff)
    {
    // need to construct pdfs in right order
    // noting that dense states are indexed s.t. the last
    // word in the ngram is the least significant 'bit'
    
    // number of ngrams, excluding last word, is
      int total_ngrams = (int)pow(float(n.get_vocab_length()),float(n.order()-1));
    
    for(i=0;i<total_ngrams;i++)
    {
        
        if ( trace )
        cerr << "\r" << i*100/total_ngrams << "%";
        
        EST_DiscreteProbDistribution this_pdf;
        const EST_StrVector this_ngram = n.make_ngram_from_index(i);
        this_pdf = n.prob_dist(this_ngram);
        
        for (k=this_pdf.item_start();
         !this_pdf.item_end(k);
         k = this_pdf.item_next(k))
        {
        
        double freq;
        EST_String name;
        this_pdf.item_freq(k,name,freq);
        if (freq == lfreq)
            count--;
        else
        {
            if (count < -1)
            fwrite(&count,sizeof(double),1,ofd);
            fwrite(&freq,sizeof(double),1,ofd);
            count = -1;
        }
        lfreq = freq;
        }
        
        
    }
    
    }
    if ( trace )
    cerr << "\r      \r" << endl;
    
    fclose(ofd);
    
    return write_ok;
}