PolySearcher*
PolySearcher_init(PolySearcher *self, Schema *schema, VArray *searchers) {
const uint32_t num_searchers = VA_Get_Size(searchers);
int32_t *starts_array = (int32_t*)MALLOCATE(num_searchers * sizeof(int32_t));
int32_t doc_max = 0;
Searcher_init((Searcher*)self, schema);
PolySearcherIVARS *const ivars = PolySearcher_IVARS(self);
ivars->searchers = (VArray*)INCREF(searchers);
ivars->starts = NULL; // Safe cleanup.
for (uint32_t i = 0; i < num_searchers; i++) {
Searcher *searcher
= (Searcher*)CERTIFY(VA_Fetch(searchers, i), SEARCHER);
Schema *candidate = Searcher_Get_Schema(searcher);
Class *orig_class = Schema_Get_Class(schema);
Class *candidate_class = Schema_Get_Class(candidate);
// Confirm that searchers all use the same schema.
if (orig_class != candidate_class) {
THROW(ERR, "Conflicting schemas: '%o', '%o'",
Schema_Get_Class_Name(schema),
Schema_Get_Class_Name(candidate));
}
// Derive doc_max and relative start offsets.
starts_array[i] = (int32_t)doc_max;
doc_max += Searcher_Doc_Max(searcher);
}
ivars->doc_max = doc_max;
ivars->starts = I32Arr_new_steal(starts_array, num_searchers);
return self;
}
PhraseCompiler*
PhraseCompiler_init(PhraseCompiler *self, PhraseQuery *parent,
Searcher *searcher, float boost) {
PhraseCompilerIVARS *const ivars = PhraseCompiler_IVARS(self);
PhraseQueryIVARS *const parent_ivars = PhraseQuery_IVARS(parent);
Schema *schema = Searcher_Get_Schema(searcher);
Similarity *sim = Schema_Fetch_Sim(schema, parent_ivars->field);
Vector *terms = parent_ivars->terms;
// Try harder to find a Similarity if necessary.
if (!sim) { sim = Schema_Get_Similarity(schema); }
// Init.
Compiler_init((Compiler*)self, (Query*)parent, searcher, sim, boost);
// Store IDF for the phrase.
ivars->idf = 0;
for (uint32_t i = 0, max = Vec_Get_Size(terms); i < max; i++) {
Obj *term = Vec_Fetch(terms, i);
int32_t doc_max = Searcher_Doc_Max(searcher);
int32_t doc_freq = Searcher_Doc_Freq(searcher, parent_ivars->field, term);
ivars->idf += Sim_IDF(sim, doc_freq, doc_max);
}
// Calculate raw weight.
ivars->raw_weight = ivars->idf * ivars->boost;
return self;
}
PhraseCompiler*
PhraseCompiler_init(PhraseCompiler *self, PhraseQuery *parent,
Searcher *searcher, float boost)
{
Schema *schema = Searcher_Get_Schema(searcher);
Similarity *sim = Schema_Fetch_Sim(schema, parent->field);
VArray *terms = parent->terms;
uint32_t i, max;
// Try harder to find a Similarity if necessary.
if (!sim) { sim = Schema_Get_Similarity(schema); }
// Init.
Compiler_init((Compiler*)self, (Query*)parent, searcher, sim, boost);
// Store IDF for the phrase.
self->idf = 0;
for (i = 0, max = VA_Get_Size(terms); i < max; i++) {
Obj *term = VA_Fetch(terms, i);
int32_t doc_max = Searcher_Doc_Max(searcher);
int32_t doc_freq = Searcher_Doc_Freq(searcher, parent->field, term);
self->idf += Sim_IDF(sim, doc_freq, doc_max);
}
// Calculate raw weight.
self->raw_weight = self->idf * self->boost;
// Make final preparations.
PhraseCompiler_Normalize(self);
return self;
}
TermCompiler*
TermCompiler_init(TermCompiler *self, Query *parent, Searcher *searcher,
float boost) {
TermCompilerIVARS *const ivars = TermCompiler_IVARS(self);
TermQueryIVARS *const parent_ivars = TermQuery_IVARS((TermQuery*)parent);
Schema *schema = Searcher_Get_Schema(searcher);
Similarity *sim = Schema_Fetch_Sim(schema, parent_ivars->field);
// Try harder to get a Similarity if necessary.
if (!sim) { sim = Schema_Get_Similarity(schema); }
// Init.
Compiler_init((Compiler*)self, parent, searcher, sim, boost);
ivars->normalized_weight = 0.0f;
ivars->query_norm_factor = 0.0f;
// Derive.
int32_t doc_max = Searcher_Doc_Max(searcher);
uint32_t doc_freq = Searcher_Doc_Freq(searcher, parent_ivars->field,
parent_ivars->term);
ivars->idf = Sim_IDF(sim, (int32_t)doc_freq, doc_max);
/* The score of any document is approximately equal to:
*
* (tf_d * idf_t / norm_d) * (tf_q * idf_t / norm_q)
*
* Here we add in the first IDF, plus user-supplied boost.
*
* The second clause is factored in by the call to Normalize().
*
* tf_d and norm_d can only be added by the Matcher, since they are
* per-document.
*/
ivars->raw_weight = ivars->idf * ivars->boost;
return self;
}
