KinoSearch::Analysis::TokenBatch - a collection of tokens


Add many tokens to the batch, by supplying the string to be tokenized, and arrays of token starts and token ends (specified in bytes).

void build_posting_list(batch, doc_num, field_num) TokenBatch *batch; U32 doc_num; U16 field_num; PPCODE: Kino_TokenBatch_build_plist(batch, doc_num, field_num);

void set_all_texts(batch, texts_av) TokenBatch *batch; AV *texts_av; PREINIT: Token *token; I32 i, max; SV **sv_ptr; char *text; STRLEN len; PPCODE: { token = batch->first; max = av_len(texts_av); for (i = 0; i <= max; i++) { if (token == NULL) { Kino_confess(``Batch size %d doesn't match array size %d'', batch->size, (max + 1)); } sv_ptr = av_fetch(texts_av, i, 0); if (sv_ptr == NULL) { Kino_confess(``Encountered a null SV* pointer''); } text = SvPV(*sv_ptr, len); Kino_Safefree(token->text); token->text = Kino_savepvn(text, len); token->len = len; token = token->next; } }

void get_all_texts(batch) TokenBatch *batch; PREINIT: Token *token; AV *out_av; PPCODE: { out_av = newAV(); token = batch->first; while (token != NULL) { SV *text = newSVpvn(token->text, token->len); av_push(out_av, text); token = token->next; } XPUSHs(sv_2mortal( newRV_noinc((SV*)out_av) )); XSRETURN(1); }

SV* _set_or_get(batch, ...) TokenBatch *batch; ALIAS: set_text = 1 get_text = 2 set_start_offset = 3 get_start_offset = 4 set_end_offset = 5 get_end_offset = 6 set_pos_inc = 7 get_pos_inc = 8 set_size = 9 get_size = 10 set_postings = 11 get_postings = 12 set_tv_string = 13 get_tv_string = 14 CODE: { /* fail if looking for info on a single token but there isn't one */ if ((ix < 7) && (batch->current == NULL)) Kino_confess(``TokenBatch doesn't currently hold a valid token'');

    KINO_START_SET_OR_GET_SWITCH
    case 1:  {
                Token *current = batch->current;
                char   *text;
                Kino_Safefree(current->text);
                text = SvPV( ST(1), current->len );
                current->text = Kino_savepvn( text, current->len );
             }
             /* fall through */
    case 2:  RETVAL = newSVpvn(batch->current->text, batch->current->len);
             break;
    case 3:  batch->current->start_offset = SvIV( ST(1) );
             /* fall through */
    case 4:  RETVAL = newSViv(batch->current->start_offset);
             break;
    case 5:  batch->current->end_offset = SvIV( ST(1) );
             /* fall through */
    case 6:  RETVAL = newSViv(batch->current->end_offset);
             break;
    case 7:  batch->current->pos_inc = SvIV( ST(1) );
             /* fall through */
    case 8:  RETVAL = newSViv(batch->current->pos_inc);
             break;
    case 9:  Kino_confess("Can't set size on a TokenBatch object");
             /* fall through */
    case 10: RETVAL = newSVuv(batch->size);
             break;
    
    case 11: Kino_confess("can't set_postings");
             /* fall through */
    case 12: RETVAL = newRV_inc( (SV*)batch->postings );
             break;
    case 13: Kino_confess("can't set_tv_string");
             /* fall through */
    case 14: RETVAL = newSVsv(batch->tv_string);
             break;
    
    KINO_END_SET_OR_GET_SWITCH
}
OUTPUT: RETVAL

void reset(batch) TokenBatch *batch; PPCODE: Kino_TokenBatch_reset(batch);

I32 next(batch) TokenBatch *batch; CODE: RETVAL = Kino_TokenBatch_next(batch); OUTPUT: RETVAL

void DESTROY(batch) TokenBatch *batch; PPCODE: Kino_TokenBatch_destroy(batch);

__H__

#ifndef H_KINOSEARCH_ANALYSIS_TOKENBATCH #define H_KINOSEARCH_ANALYSIS_TOKENBATCH 1

#include ``EXTERN.h'' #include ``perl.h'' #include ``XSUB.h'' #include ``ppport.h'' #include ``KinoSearchAnalysisToken.h'' #include ``KinoSearchIndexTerm.h'' #include ``KinoSearchUtilCarp.h'' #include ``KinoSearchUtilMathUtils.h'' #include ``KinoSearchUtilMemManager.h'' #include ``KinoSearchUtilStringHelper.h''

typedef struct tokenbatch { Token *first; Token *last; Token *current; I32 size; I32 initialized; AV *postings; SV *tv_string; } TokenBatch;

TokenBatch* Kino_TokenBatch_new(); void Kino_TokenBatch_destroy(TokenBatch *batch); void Kino_TokenBatch_append(TokenBatch *batch, Token *token); I32 Kino_TokenBatch_next(TokenBatch *batch); void Kino_TokenBatch_reset(TokenBatch *batch); void Kino_TokenBatch_build_plist(TokenBatch*, U32, U16);

#endif /* include guard */

__C__

#include ``KinoSearchAnalysisTokenBatch.h''

TokenBatch* Kino_TokenBatch_new() { TokenBatch *batch;

    /* allocate */
    Kino_New(0, batch, 1, TokenBatch);
    /* init */
    batch->first        = NULL;
    batch->last         = NULL;
    batch->current      = NULL;
    batch->size         = 0;
    batch->initialized  = 0;
    batch->tv_string    = &PL_sv_undef;
    batch->postings     = (AV*)&PL_sv_undef;
    return batch;
}

void Kino_TokenBatch_destroy(TokenBatch *batch) { Token *token = batch->first; while (token != NULL) { Token *next = token->next; Kino_Token_destroy(token); token = next; } SvREFCNT_dec( (SV*)batch->postings ); SvREFCNT_dec(batch->tv_string); Kino_Safefree(batch); }

I32 Kino_TokenBatch_next(TokenBatch *batch) { /* enter iterative mode */ if (batch->initialized == 0) { batch->current = batch->first; batch->initialized = 1; } /* continue iterative mode */ else { batch->current = batch->current->next; } return batch->current == NULL ? 0 : 1; }

void Kino_TokenBatch_reset(TokenBatch *batch) { batch->initialized = 0; }

void Kino_TokenBatch_append(TokenBatch *batch, Token *token) { token->next = NULL; token->prev = batch->last;

    /* if this is the first token added, init */
    if (batch->first == NULL) {
        batch->first   = token;
        batch->last    = token;
    }
    else {
        batch->last->next = token;
        batch->last       = token;
    }
    batch->size++;
}

#define POSDATA_LEN 12 #define DOC_NUM_LEN 4 #define NULL_BYTE_LEN 1 #define TEXT_LEN_LEN 2

/* Encode postings in the serialized format expected by PostingsWriter, plus * the term vector expected by FieldsWriter. */ void Kino_TokenBatch_build_plist(TokenBatch *batch, U32 doc_num, U16 field_num) { char doc_num_buf[4]; char field_num_buf[2]; char text_len_buf[2]; char vint_buf[5]; HV *pos_hash; HE *he; AV *out_av; I32 i = 0; I32 overlap, num_bytes, num_positions; I32 num_postings = 0; SV **sv_ptr; char *text, *source_ptr, *dest_ptr, *end_ptr; char *last_text = ``''; STRLEN text_len, len, fake_len; STRLEN last_len = 0; SV *serialized_sv; SV *tv_string_sv; U32 *source_u32, *dest_u32, *end_u32;

    /* prepare doc num and field num in anticipation of upcoming loop */
    Kino_encode_bigend_U32(doc_num, doc_num_buf);
    Kino_encode_bigend_U16(field_num, field_num_buf);
    /* build a posting list hash */
    pos_hash = newHV();
    while (Kino_TokenBatch_next(batch)) {
        Token* token = batch->current;
        /* either start a new hash entry or retrieve an existing one */
        if (!hv_exists(pos_hash, token->text, token->len)) {
            /* the values are the serialized scalars */
            if (token->len > 65535) 
                Kino_confess("Maximum token length is 65535; got %d", 
                    token->len);
            Kino_encode_bigend_U16(token->len, text_len_buf);
            /* allocate the serialized scalar */
            len =   TEXT_LEN_LEN       /* for now, put text_len at top */
                  + KINO_FIELD_NUM_LEN /* encoded field number */
                  + token->len         /* term text */
                  + NULL_BYTE_LEN      /* the term text's null byte */
                  + DOC_NUM_LEN 
                  + POSDATA_LEN
                  + TEXT_LEN_LEN       /* eventually, text_len goes at end */
                  + NULL_BYTE_LEN;     /* the scalar's null byte */ 
            serialized_sv = newSV(len);
            SvPOK_on(serialized_sv);
            source_ptr = SvPVX(serialized_sv);
            dest_ptr   = source_ptr;
            /* concatenate a bunch of stuff onto the serialized scalar */
            Copy(text_len_buf, dest_ptr, TEXT_LEN_LEN, char);
            dest_ptr += TEXT_LEN_LEN;
            Copy(field_num_buf, dest_ptr, KINO_FIELD_NUM_LEN, char);
            dest_ptr += KINO_FIELD_NUM_LEN;
            Copy(token->text, dest_ptr, token->len, char);
            dest_ptr += token->len;
            *dest_ptr = '\0';
            dest_ptr += NULL_BYTE_LEN;
            Copy(doc_num_buf, dest_ptr, DOC_NUM_LEN, char);
            dest_ptr += DOC_NUM_LEN;
            SvCUR_set(serialized_sv, (dest_ptr - source_ptr));
            /* store the text => serialized_sv pair in the pos_hash */
            (void)hv_store(pos_hash, token->text, token->len, serialized_sv, 0); 
        }
        else {
            /* retrieve the serialized scalar and allocate more space */
            sv_ptr = hv_fetch(pos_hash, token->text, token->len, 0);
            if (sv_ptr == NULL) 
                Kino_confess("unexpected null sv_ptr");
            serialized_sv = *sv_ptr;
            len = SvCUR(serialized_sv)
                + POSDATA_LEN    /* allocate space for upcoming posdata */
                + TEXT_LEN_LEN   /* extra space for encoded text length */
                + NULL_BYTE_LEN; 
            SvGROW( serialized_sv, len );
        }
        /* append position, start offset, end offset to the serialized_sv */
        dest_u32 = (U32*)SvEND(serialized_sv);
        *dest_u32++ = (U32)i;
        i += token->pos_inc;
        *dest_u32++ = token->start_offset;
        *dest_u32++ = token->end_offset;
        len = SvCUR(serialized_sv) + POSDATA_LEN;
        SvCUR_set(serialized_sv, len);
        /* destroy the token, because nobody else will -- XXX MAYBE? */
        /* Kino_Token_destroy(token); */
    }
    /* allocate and presize the array to hold the output */
    num_postings = hv_iterinit(pos_hash);
    out_av = newAV();
    av_extend(out_av, num_postings);
    /* collect serialized scalars into an array */
    i = 0;
    while ((he = hv_iternext(pos_hash))) {
        serialized_sv = HeVAL(he);
        /* transfer text_len to end of serialized scalar */
        source_ptr = SvPVX(serialized_sv);
        dest_ptr   = SvEND(serialized_sv);
        Copy(source_ptr, dest_ptr, TEXT_LEN_LEN, char);
        SvCUR(serialized_sv) += TEXT_LEN_LEN;
        source_ptr += TEXT_LEN_LEN;
        sv_chop(serialized_sv, source_ptr);
        SvREFCNT_inc(serialized_sv);
        av_store(out_av, i, serialized_sv);
        i++;
    }
    /* we're done with the positions hash, so kill it off */
    SvREFCNT_dec(pos_hash);
    /* start the term vector string */
    tv_string_sv = newSV(20);
    SvPOK_on(tv_string_sv);
    num_bytes = Kino_OutStream_encode_vint(num_postings, vint_buf);
    sv_catpvn(tv_string_sv, vint_buf, num_bytes);
    /* sort the posting lists lexically */
    sortsv(AvARRAY(out_av), num_postings, Perl_sv_cmp);
    /* iterate through the array, making changes to the serialized scalars */
    for (i = 0; i < num_postings; i++) {
        serialized_sv = *(av_fetch(out_av, i, 0));
        /* find the beginning of the term text */
        text = SvPV(serialized_sv, fake_len);
        text += KINO_FIELD_NUM_LEN;
        /* save the text_len; we'll move it forward later */
        end_ptr = SvEND(serialized_sv) - TEXT_LEN_LEN;
        text_len = Kino_decode_bigend_U16( end_ptr );
        Kino_encode_bigend_U16(text_len, text_len_buf);
        source_ptr = SvPVX(serialized_sv) + 
            KINO_FIELD_NUM_LEN + text_len + NULL_BYTE_LEN + DOC_NUM_LEN;
        source_u32 = (U32*)source_ptr;
        dest_u32   = source_u32;
        end_u32    = (U32*)end_ptr;
        /* append the string diff to the tv_string */
        overlap = Kino_StrHelp_string_diff(last_text, text, 
            last_len, text_len);
        num_bytes = Kino_OutStream_encode_vint(overlap, vint_buf);
        sv_catpvn( tv_string_sv, vint_buf, num_bytes );
        num_bytes = Kino_OutStream_encode_vint(
            (text_len - overlap), vint_buf );
        sv_catpvn( tv_string_sv, vint_buf, num_bytes );
        sv_catpvn( tv_string_sv, (text + overlap), (text_len - overlap) );
        /* append the number of positions for this term */
        num_positions =   SvCUR(serialized_sv) 
                        - KINO_FIELD_NUM_LEN
                        - text_len 
                        - NULL_BYTE_LEN
                        - DOC_NUM_LEN 
                        - TEXT_LEN_LEN;
        num_positions /= POSDATA_LEN;
        num_bytes = Kino_OutStream_encode_vint(num_positions, vint_buf);
        sv_catpvn( tv_string_sv, vint_buf, num_bytes );
        while (source_u32 < end_u32) {
            /* keep only the positions in the serialized scalars */
            num_bytes = Kino_OutStream_encode_vint(*source_u32, vint_buf);
            sv_catpvn( tv_string_sv, vint_buf, num_bytes );
            *dest_u32++ = *source_u32++;
            /* add start_offset to tv_string */
            num_bytes = Kino_OutStream_encode_vint(*source_u32, vint_buf);
            sv_catpvn( tv_string_sv, vint_buf, num_bytes );
            source_u32++;
            /* add end_offset to tv_string */
            num_bytes = Kino_OutStream_encode_vint(*source_u32, vint_buf);
            sv_catpvn( tv_string_sv, vint_buf, num_bytes );
            source_u32++;
        }
        /* restore the text_len and close the scalar */
        dest_ptr = (char*)dest_u32;
        Copy(text_len_buf, dest_ptr, TEXT_LEN_LEN, char);
        dest_ptr += TEXT_LEN_LEN;
        len = dest_ptr - SvPVX(serialized_sv);
        SvCUR_set(serialized_sv, len);
        last_text = text;
        last_len  = text_len;
    }
    
    /* store the postings array and the term vector string */
    SvREFCNT_dec(batch->tv_string);
    batch->tv_string = tv_string_sv;
    SvREFCNT_dec(batch->postings);
    batch->postings = out_av;
}

__POD__

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NAME

KinoSearch::Analysis::TokenBatch - a collection of tokens

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SYNOPSIS

    while ( $batch->next ) {
        $batch->set_text( lc( $batch->get_text ) );
    }

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EXPERIMENTAL API

TokenBatch's API should be considered experimental and is likely to change.

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DESCRIPTION

A TokenBatch is a collection of Tokens which you can add to, then iterate over.

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METHODS

new

    my $batch = KinoSearch::Analysis::TokenBatch->new;

Constructor.

append

    $batch->append( $text, $start_offset, $end_offset, $pos_inc );

Add a Token to the end of the batch. Accepts either three or four arguments: text, start_offset, end_offset, and an optional position increment which defaults to 1 if not supplied. For a description of what these arguments mean, see the docs for Token.

next

    while ( $batch->next ) {
        # ...
    }

Proceed to the next token in the TokenBatch. Returns true if the TokenBatch ends up located at valid token.

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ACCESSOR METHODS

All of TokenBatch's accessor methods affect the current Token. Calling any of these methods when the TokenBatch is not located at a valid Token will trigger an exception.

set_text get_text

Set/get the text of the current Token.

set_start_offset get_start_offset

Set/get the start_offset of the current Token.

set_end_offset get_end_offset

Set/get the end_offset of the current Token.

set_pos_inc get_pos_inc

Set/get the position increment of the current Token.

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COPYRIGHT

Copyright 2005-2006 Marvin Humphrey

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LICENSE, DISCLAIMER, BUGS, etc.

See KinoSearch version 0.15.

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 KinoSearch::Analysis::TokenBatch - a collection of tokens