in crossdc-producer/src/main/java/org/apache/solr/update/processor/MirroringUpdateProcessor.java [404:418]
public static long estimate(SolrInputDocument doc) {
if (doc == null) return 0L;
long size = 0;
for (SolrInputField inputField : doc.values()) {
size += primitiveEstimate(inputField.getName(), 0L);
size += estimate(inputField.getValue());
}
if (doc.hasChildDocuments()) {
for (SolrInputDocument childDoc : doc.getChildDocuments()) {
size += estimate(childDoc);
}
}
return size;
}