Revision 86a0133d0527a1005ebd9b517fa973c1a4a0a1ae authored by sdong on 23 April 2014, 01:31:55 UTC, committed by sdong on 23 April 2014, 02:29:05 UTC
Summary: This is a temp solution to expose index sizes to users from PlainTableReader before we persistent them to files. In this patch, the memory consumption of indexes used by PlainTableReader will be reported as two user defined properties, so that users can monitor them. Test Plan: Add a unit test. make all check` Reviewers: haobo, ljin Reviewed By: haobo CC: nkg-, yhchiang, igor, ljin, dhruba, leveldb Differential Revision: https://reviews.facebook.net/D18195
1 parent 1068d2f
comparator.cc
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include <algorithm>
#include <stdint.h>
#include "rocksdb/comparator.h"
#include "rocksdb/slice.h"
#include "port/port.h"
#include "util/logging.h"
namespace rocksdb {
Comparator::~Comparator() { }
namespace {
class BytewiseComparatorImpl : public Comparator {
public:
BytewiseComparatorImpl() { }
virtual const char* Name() const {
return "leveldb.BytewiseComparator";
}
virtual int Compare(const Slice& a, const Slice& b) const {
return a.compare(b);
}
virtual void FindShortestSeparator(
std::string* start,
const Slice& limit) const {
// Find length of common prefix
size_t min_length = std::min(start->size(), limit.size());
size_t diff_index = 0;
while ((diff_index < min_length) &&
((*start)[diff_index] == limit[diff_index])) {
diff_index++;
}
if (diff_index >= min_length) {
// Do not shorten if one string is a prefix of the other
} else {
uint8_t diff_byte = static_cast<uint8_t>((*start)[diff_index]);
if (diff_byte < static_cast<uint8_t>(0xff) &&
diff_byte + 1 < static_cast<uint8_t>(limit[diff_index])) {
(*start)[diff_index]++;
start->resize(diff_index + 1);
assert(Compare(*start, limit) < 0);
}
}
}
virtual void FindShortSuccessor(std::string* key) const {
// Find first character that can be incremented
size_t n = key->size();
for (size_t i = 0; i < n; i++) {
const uint8_t byte = (*key)[i];
if (byte != static_cast<uint8_t>(0xff)) {
(*key)[i] = byte + 1;
key->resize(i+1);
return;
}
}
// *key is a run of 0xffs. Leave it alone.
}
};
} // namespace
static port::OnceType once = LEVELDB_ONCE_INIT;
static const Comparator* bytewise;
static void InitModule() {
bytewise = new BytewiseComparatorImpl;
}
const Comparator* BytewiseComparator() {
port::InitOnce(&once, InitModule);
return bytewise;
}
} // namespace rocksdb
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