foundationdb/fdbclient/FDBTypes.cpp

76 lines
2.6 KiB
C++

/*
* FDBTypes.cpp
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "fdbclient/FDBTypes.h"
#include "fdbclient/Knobs.h"
KeyRef keyBetween(const KeyRangeRef& keys) {
int pos = 0; // will be the position of the first difference between keys.begin and keys.end
int minSize = std::min(keys.begin.size(), keys.end.size());
for (; pos < minSize && pos < CLIENT_KNOBS->SPLIT_KEY_SIZE_LIMIT; pos++) {
if (keys.begin[pos] != keys.end[pos]) {
return keys.end.substr(0, pos + 1);
}
}
// If one more character keeps us in the limit, and the latter key is simply
// longer, then we only need one more byte of the end string.
if (pos < CLIENT_KNOBS->SPLIT_KEY_SIZE_LIMIT && keys.begin.size() < keys.end.size()) {
return keys.end.substr(0, pos + 1);
}
return keys.end;
}
void KeySelectorRef::setKey(KeyRef const& key) {
// There are no keys in the database with size greater than KEY_SIZE_LIMIT, so if this key selector has a key
// which is large, then we can translate it to an equivalent key selector with a smaller key
if (key.size() >
(key.startsWith(LiteralStringRef("\xff")) ? CLIENT_KNOBS->SYSTEM_KEY_SIZE_LIMIT : CLIENT_KNOBS->KEY_SIZE_LIMIT))
this->key = key.substr(0,
(key.startsWith(LiteralStringRef("\xff")) ? CLIENT_KNOBS->SYSTEM_KEY_SIZE_LIMIT
: CLIENT_KNOBS->KEY_SIZE_LIMIT) +
1);
else
this->key = key;
}
std::string KeySelectorRef::toString() const {
if (offset > 0) {
if (orEqual)
return format("%d+firstGreaterThan(%s)", offset - 1, printable(key).c_str());
else
return format("%d+firstGreaterOrEqual(%s)", offset - 1, printable(key).c_str());
} else {
if (orEqual)
return format("%d+lastLessOrEqual(%s)", offset, printable(key).c_str());
else
return format("%d+lastLessThan(%s)", offset, printable(key).c_str());
}
}
std::string describe(const std::string& s) {
return s;
}
std::string describe(UID const& item) {
return item.shortString();
}