/***********************************************

 !!!! DO NOT EDIT THIS FILE !!!!

 This file was auto-generated by Build.PL from
 lib/KinoSearch/Index/TermInfosWriter.pm

 See KinoSearch::Docs::DevGuide for details.

 ***********************************************/

#line 195 "lib/KinoSearch/Index/TermInfosWriter.pm"

#include "KinoSearchIndexTermInfosWriter.h"

TermInfosWriter*
Kino_TInfosWriter_new(SV *outstream_sv, I32 is_index, I32 index_interval, 
                      I32 skip_interval) {
    TermInfosWriter *obj;

    /* allocate */
    Kino_New(0, obj, 1, TermInfosWriter);

    /* assign */
    obj->is_index       = is_index;
    obj->index_interval = index_interval;
    obj->skip_interval  = skip_interval;
    obj->fh_sv          = newSVsv(outstream_sv);
    Kino_extract_struct(obj->fh_sv, obj->fh, OutStream*,
        "KinoSearch::Store::OutStream");
    /* NOTE: this value forces the first field_num in the .tii file to -1.
     * Do not change it. */
    obj->last_termstring    = Kino_BB_new_string("\xff\xff", 2);
    obj->last_tinfo         = Kino_TInfo_new();
    obj->last_fieldnum      = -1;
    obj->last_tis_ptr       = 0,
    obj->size               = 0;
    obj->other              = NULL;
    obj->other_sv           = &PL_sv_undef;
 
    /* write file header */
    obj->fh->write_int(obj->fh, KINO_TINFOS_FORMAT);
    obj->fh->write_long(obj->fh, 0.0); /* return to fill in later */
    obj->fh->write_int(obj->fh, index_interval);
    obj->fh->write_int(obj->fh, skip_interval);

    return obj;
}


/* Write out a term/terminfo combo. */
void 
Kino_TInfosWriter_add(TermInfosWriter* obj, ByteBuf* termstring_bb,
                      TermInfo* tinfo) {
    char      *termstring, *last_tstring;
    STRLEN     termstring_len, last_tstring_len;

    I32        field_num;
    I32        overlap;
    char      *diff_start_str;
    STRLEN     diff_len;
    OutStream* fh;

    /* make local copy */
    fh = obj->fh;

    /* write a subset of the entries to the .tii index */
    if (    (obj->size % obj->index_interval == 0)
         && (!obj->is_index)               
    ) {
        Kino_TInfosWriter_add(obj->other, obj->last_termstring,
        obj->last_tinfo);
    }

    /* extract string pointers and string lengths */
    termstring       = termstring_bb->ptr;
    last_tstring     = obj->last_termstring->ptr;
    termstring_len   = termstring_bb->size;
    last_tstring_len = obj->last_termstring->size;

    /* to obtain field number, decode packed 'n' at top of termstring */
    field_num = (I16)Kino_decode_bigend_U16(termstring);

    /* move past field_num */
    termstring       += KINO_FIELD_NUM_LEN;
    last_tstring     += KINO_FIELD_NUM_LEN;
    termstring_len   -= KINO_FIELD_NUM_LEN;
    last_tstring_len -= KINO_FIELD_NUM_LEN;

    /* count how many bytes the strings share at the top */ 
    overlap = Kino_StrHelp_string_diff(last_tstring, termstring,
        last_tstring_len, termstring_len);
    diff_start_str = termstring + overlap;
    diff_len       = termstring_len - overlap;

    /* write number of common bytes */
    fh->write_vint(fh, overlap);

    /* write common bytes */
    fh->write_string(fh, diff_start_str, diff_len);
    
    /* write field number and doc_freq */
    fh->write_vint(fh, field_num);
    fh->write_vint(fh, tinfo->doc_freq);

    /* delta encode filepointers */
    fh->write_vlong(fh, (tinfo->frq_fileptr - obj->last_tinfo->frq_fileptr) );
    fh->write_vlong(fh, (tinfo->prx_fileptr - obj->last_tinfo->prx_fileptr) );

    /* write skipdata */
    if (tinfo->doc_freq >= obj->skip_interval)
        fh->write_vint(fh, tinfo->skip_offset);

    /* the .tii index file gets a pointer to the location of the primary */
    if (obj->is_index) {
        double tis_ptr;

        tis_ptr = obj->other->fh->tell(obj->other->fh);
        obj->fh->write_vlong(obj->fh, (tis_ptr - obj->last_tis_ptr));
        obj->last_tis_ptr = tis_ptr;
    }

    /* track number of terms */
    obj->size++;

    /* remember for delta encoding */
    Kino_BB_assign_string(obj->last_termstring, termstring_bb->ptr,
        termstring_bb->size);
    StructCopy(tinfo, obj->last_tinfo, TermInfo);
}

void
Kino_TInfosWriter_destroy(TermInfosWriter *obj) {
    SvREFCNT_dec(obj->fh_sv);
    SvREFCNT_dec(obj->other_sv);
    Kino_BB_destroy(obj->last_termstring);
    Kino_TInfo_destroy(obj->last_tinfo);
    Kino_Safefree(obj);
}