diff query.cpp @ 528:561339c7fd26 multiprobeLSH

Added audiodb_datum_qpointers_partial() to make exact evaluation of LSH results more efficient. This routine calculates partial sums only for those vectors needed.

--- a/query.cpp	Wed Jan 28 18:55:46 2009 +0000
+++ b/query.cpp	Thu Jan 29 13:44:47 2009 +0000
@@ -280,6 +280,58 @@
   return 0;
 }
 
+int audiodb_datum_qpointers_partial(adb_datum_t *d, uint32_t sequence_length, double **vector_data, 
+				    double **vector, adb_qpointers_internal_t *qpointers, 
+				    adb_qstate_internal_t *qstate){
+  uint32_t nvectors = d->nvectors;
+  qpointers->nvectors = nvectors;
+  std::priority_queue<PointPair> ppairs(*qstate->exact_evaluation_queue);
+  
+  size_t vector_size = nvectors * sizeof(double) * d->dim;
+  *vector_data = new double[vector_size];
+  qpointers->l2norm_data = new double[vector_size / d->dim];
+  if(d->power)
+    qpointers->power_data = new double[vector_size / d->dim];
+
+  uint32_t seq_len_dbl = sequence_length*d->dim*sizeof(double);
+  PointPair pp = ppairs.top();
+  uint32_t tid = pp.trackID;
+
+  while( !ppairs.empty() && pp.trackID==tid){
+    uint32_t spos = pp.spos;
+    uint32_t spos_dim = spos*d->dim;
+
+    memcpy(*vector_data+spos_dim, d->data+spos_dim, seq_len_dbl); 
+
+    audiodb_l2norm_buffer(*vector_data+spos_dim, d->dim, 1, qpointers->l2norm_data+spos);
+    audiodb_sequence_sum(qpointers->l2norm_data+spos, sequence_length, sequence_length);
+    audiodb_sequence_sqrt(qpointers->l2norm_data+spos, sequence_length, sequence_length);
+
+    if(d->power) {
+      memcpy(qpointers->power_data+spos, d->power+spos, seq_len_dbl);
+      audiodb_sequence_sum(qpointers->power_data+spos, sequence_length, sequence_length);
+      audiodb_sequence_average(qpointers->power_data+spos, sequence_length, sequence_length);
+    }
+    ppairs.pop();
+    if(!ppairs.empty())
+      pp = ppairs.top();
+  }
+
+  if(d->times) {
+    qpointers->mean_duration = new double[1];
+    *qpointers->mean_duration = 0;
+    for(unsigned int k = 0; k < nvectors; k++) {
+      *qpointers->mean_duration += d->times[2*k+1] - d->times[2*k];
+    }
+    *qpointers->mean_duration /= nvectors;
+  }  
+
+  *vector = *vector_data;
+  qpointers->l2norm = qpointers->l2norm_data;
+  qpointers->power = qpointers->power_data;
+  return 0;
+}
+
 int audiodb_query_spec_qpointers(adb_t *adb, const adb_query_spec_t *spec, double **vector_data, double **vector, adb_qpointers_internal_t *qpointers) {
   adb_datum_t *datum;
   adb_datum_t d = {0};
@@ -466,7 +518,7 @@
         delete qstate->exact_evaluation_queue;
         return 1;
       }
-      if(audiodb_datum_qpointers(&d, sequence_length, &dbdata, &dbdata_pointer, &dbpointers)) {
+      if(audiodb_datum_qpointers_partial(&d, sequence_length, &dbdata, &dbdata_pointer, &dbpointers, qstate)) {
         delete qstate->exact_evaluation_queue;
         audiodb_free_datum(&d);
         return 1;