blob: 200cece55adf62f81f5f00cd1715aa74ac22e39d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
// Copyright (c) Meta Platforms, Inc. and affiliates.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "db/coalescing_iterator.h"
#include "db/wide/wide_columns_helper.h"
namespace ROCKSDB_NAMESPACE {
void CoalescingIterator::Coalesce(
const autovector<MultiCfIteratorInfo>& items) {
assert(wide_columns_.empty());
MinHeap heap;
for (const auto& item : items) {
assert(item.iterator);
for (auto& column : item.iterator->columns()) {
heap.push(WideColumnWithOrder{&column, item.order});
}
}
if (heap.empty()) {
return;
}
wide_columns_.reserve(heap.size());
auto current = heap.top();
heap.pop();
while (!heap.empty()) {
int comparison = current.column->name().compare(heap.top().column->name());
if (comparison < 0) {
wide_columns_.push_back(*current.column);
} else if (comparison > 0) {
// Shouldn't reach here.
// Current item in the heap is greater than the top item in the min heap
assert(false);
}
current = heap.top();
heap.pop();
}
wide_columns_.push_back(*current.column);
if (WideColumnsHelper::HasDefaultColumn(wide_columns_)) {
value_ = WideColumnsHelper::GetDefaultColumn(wide_columns_);
}
}
} // namespace ROCKSDB_NAMESPACE
|
