Why not add all files at the level level directly to guards_compaction_and_all_files instead of taking the intersection of Complete_guards and Guards? I'm a little confused about this code, so I'd appreciate explaining it 。
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int guard_index_iter = 0;
for (size_t i = 0; i < complete_guards.size(); i++) {
GuardMetaData* cg = complete_guards[i];
int guard_index = -1;
Slice guard_key = cg->guard_key.user_key(), next_guard_key;
if (i + 1 < complete_guards.size()) {
next_guard_key = complete_guards[i+1]->guard_key.user_key();
}
for (; guard_index_iter < guards.size(); guard_index_iter++) {
int compare = icmp_.user_comparator()->Compare(guards[guard_index_iter]->guard_key.user_key(), guard_key);
if (compare == 0) {
guard_index = guard_index_iter;
guard_index_iter++;
break;
} else if (compare > 0) {
break;
} else {
// Ideally it should never reach here since there are no duplicates in complete_guards and complete_guards is a superset of guards
}
}
if (guard_index == -1) { // If guard is not found for this complete guard
continue;
}
GuardMetaData* g = guards[guard_index];
bool guard_added = false;
for (unsigned j = 0; j < g->files.size(); j++) {
FileMetaData* file = g->file_metas[j];
Slice file_smallest = file->smallest.user_key();
Slice file_largest = file->largest.user_key();
if ((i < complete_guards.size()-1 // If it is not the last guard, checking for smallest and largest to fit in the range
&& (icmp_.user_comparator()->Compare(file_smallest, guard_key) < 0
|| icmp_.user_comparator()->Compare(file_largest, next_guard_key) >= 0))
|| (i == complete_guards.size()-1 // If it is the last guard, checking for the smallest to fit in the guard
&& icmp_.user_comparator()->Compare(file_smallest, guard_key) < 0)) {
guards_to_add_to_compaction.push_back(g);
guards_compaction_add_all_files.push_back(true);
guard_added = true;
break; // No need to check other files
}
}
if (!guard_added && which == 0 && (force_compact || v->guard_compaction_scores_[current_level][guard_index] >= 1.0)) {
guards_to_add_to_compaction.push_back(g);
guards_compaction_add_all_files.push_back(false);
continue;
}
}
Why not add all files at the level level directly to guards_compaction_and_all_files instead of taking the intersection of Complete_guards and Guards? I'm a little confused about this code, so I'd appreciate explaining it 。
`
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