foundationdb/fdbclient/KeyRangeMap.actor.cpp

261 lines
11 KiB
C++

/*
* KeyRangeMap.actor.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/KeyRangeMap.h"
#include "fdbclient/NativeAPI.actor.h"
#include "fdbclient/CommitTransaction.h"
#include "fdbclient/FDBTypes.h"
#include "fdbclient/ReadYourWrites.h"
#include "flow/actorcompiler.h" // has to be last include
void KeyRangeActorMap::getRangesAffectedByInsertion(const KeyRangeRef& keys, vector<KeyRange>& affectedRanges) {
auto s = map.rangeContaining(keys.begin);
if (s.begin() != keys.begin && s.value().isValid() && !s.value().isReady())
affectedRanges.push_back(KeyRangeRef(s.begin(), keys.begin));
affectedRanges.push_back(keys);
auto e = map.rangeContaining(keys.end);
if (e.begin() != keys.end && e.value().isValid() && !e.value().isReady())
affectedRanges.push_back(KeyRangeRef(keys.end, e.end()));
}
Standalone<RangeResultRef> krmDecodeRanges(KeyRef mapPrefix, KeyRange keys, Standalone<RangeResultRef> kv) {
ASSERT(!kv.more || kv.size() > 1);
KeyRange withPrefix =
KeyRangeRef(mapPrefix.toString() + keys.begin.toString(), mapPrefix.toString() + keys.end.toString());
ValueRef beginValue, endValue;
if (kv.size() && kv[0].key.startsWith(mapPrefix))
beginValue = kv[0].value;
if (kv.size() && kv.end()[-1].key.startsWith(mapPrefix))
endValue = kv.end()[-1].value;
Standalone<RangeResultRef> result;
result.arena().dependsOn(kv.arena());
result.arena().dependsOn(keys.arena());
result.push_back(result.arena(), KeyValueRef(keys.begin, beginValue));
for (int i = 0; i < kv.size(); i++) {
if (kv[i].key > withPrefix.begin && kv[i].key < withPrefix.end) {
KeyRef k = kv[i].key.removePrefix(mapPrefix);
result.push_back(result.arena(), KeyValueRef(k, kv[i].value));
} else if (kv[i].key >= withPrefix.end)
kv.more = false;
}
if (!kv.more)
result.push_back(result.arena(), KeyValueRef(keys.end, endValue));
result.more = kv.more;
return result;
}
// Returns keys.begin, all transitional points in keys, and keys.end, and their values
ACTOR Future<Standalone<RangeResultRef>> krmGetRanges(Transaction* tr,
Key mapPrefix,
KeyRange keys,
int limit,
int limitBytes) {
KeyRange withPrefix =
KeyRangeRef(mapPrefix.toString() + keys.begin.toString(), mapPrefix.toString() + keys.end.toString());
state GetRangeLimits limits(limit, limitBytes);
limits.minRows = 2;
Standalone<RangeResultRef> kv =
wait(tr->getRange(lastLessOrEqual(withPrefix.begin), firstGreaterThan(withPrefix.end), limits));
return krmDecodeRanges(mapPrefix, keys, kv);
}
ACTOR Future<Standalone<RangeResultRef>> krmGetRanges(Reference<ReadYourWritesTransaction> tr,
Key mapPrefix,
KeyRange keys,
int limit,
int limitBytes) {
KeyRange withPrefix =
KeyRangeRef(mapPrefix.toString() + keys.begin.toString(), mapPrefix.toString() + keys.end.toString());
state GetRangeLimits limits(limit, limitBytes);
limits.minRows = 2;
Standalone<RangeResultRef> kv =
wait(tr->getRange(lastLessOrEqual(withPrefix.begin), firstGreaterThan(withPrefix.end), limits));
return krmDecodeRanges(mapPrefix, keys, kv);
}
void krmSetPreviouslyEmptyRange(Transaction* tr,
const KeyRef& mapPrefix,
const KeyRangeRef& keys,
const ValueRef& newValue,
const ValueRef& oldEndValue) {
KeyRange withPrefix =
KeyRangeRef(mapPrefix.toString() + keys.begin.toString(), mapPrefix.toString() + keys.end.toString());
tr->set(withPrefix.begin, newValue);
tr->set(withPrefix.end, oldEndValue);
}
void krmSetPreviouslyEmptyRange(CommitTransactionRef& tr,
Arena& trArena,
const KeyRef& mapPrefix,
const KeyRangeRef& keys,
const ValueRef& newValue,
const ValueRef& oldEndValue) {
KeyRange withPrefix =
KeyRangeRef(mapPrefix.toString() + keys.begin.toString(), mapPrefix.toString() + keys.end.toString());
tr.set(trArena, withPrefix.begin, newValue);
tr.set(trArena, withPrefix.end, oldEndValue);
}
ACTOR Future<Void> krmSetRange(Transaction* tr, Key mapPrefix, KeyRange range, Value value) {
state KeyRange withPrefix =
KeyRangeRef(mapPrefix.toString() + range.begin.toString(), mapPrefix.toString() + range.end.toString());
Standalone<RangeResultRef> old =
wait(tr->getRange(lastLessOrEqual(withPrefix.end), firstGreaterThan(withPrefix.end), 1, true));
Value oldValue;
bool hasResult = old.size() > 0 && old[0].key.startsWith(mapPrefix);
if (hasResult)
oldValue = old[0].value;
KeyRange conflictRange = KeyRangeRef(hasResult ? old[0].key : mapPrefix.toString(), keyAfter(withPrefix.end));
if (!conflictRange.empty())
tr->addReadConflictRange(conflictRange);
tr->clear(withPrefix);
tr->set(withPrefix.begin, value);
tr->set(withPrefix.end, oldValue);
return Void();
}
ACTOR Future<Void> krmSetRange(Reference<ReadYourWritesTransaction> tr, Key mapPrefix, KeyRange range, Value value) {
state KeyRange withPrefix =
KeyRangeRef(mapPrefix.toString() + range.begin.toString(), mapPrefix.toString() + range.end.toString());
Standalone<RangeResultRef> old =
wait(tr->getRange(lastLessOrEqual(withPrefix.end), firstGreaterThan(withPrefix.end), 1, true));
Value oldValue;
bool hasResult = old.size() > 0 && old[0].key.startsWith(mapPrefix);
if (hasResult)
oldValue = old[0].value;
KeyRange conflictRange = KeyRangeRef(hasResult ? old[0].key : mapPrefix.toString(), keyAfter(withPrefix.end));
if (!conflictRange.empty())
tr->addReadConflictRange(conflictRange);
tr->clear(withPrefix);
tr->set(withPrefix.begin, value);
tr->set(withPrefix.end, oldValue);
return Void();
}
// Sets a range of keys in a key range map, coalescing with adjacent regions if the values match
// Ranges outside of maxRange will not be coalesced
// CAUTION: use care when attempting to coalesce multiple ranges in the same prefix in a single transaction
ACTOR template <class Transaction>
static Future<Void> krmSetRangeCoalescing_(Transaction* tr,
Key mapPrefix,
KeyRange range,
KeyRange maxRange,
Value value) {
ASSERT(maxRange.contains(range));
state KeyRange withPrefix =
KeyRangeRef(mapPrefix.toString() + range.begin.toString(), mapPrefix.toString() + range.end.toString());
state KeyRange maxWithPrefix =
KeyRangeRef(mapPrefix.toString() + maxRange.begin.toString(), mapPrefix.toString() + maxRange.end.toString());
state vector<Future<Standalone<RangeResultRef>>> keys;
keys.push_back(tr->getRange(lastLessThan(withPrefix.begin), firstGreaterOrEqual(withPrefix.begin), 1, true));
keys.push_back(tr->getRange(lastLessOrEqual(withPrefix.end), firstGreaterThan(withPrefix.end) + 1, 2, true));
wait(waitForAll(keys));
// Determine how far to extend this range at the beginning
auto beginRange = keys[0].get();
bool hasBegin = beginRange.size() > 0 && beginRange[0].key.startsWith(mapPrefix);
Value beginValue = hasBegin ? beginRange[0].value : LiteralStringRef("");
state Key beginKey = withPrefix.begin;
if (beginValue == value) {
bool outsideRange = !hasBegin || beginRange[0].key < maxWithPrefix.begin;
beginKey = outsideRange ? maxWithPrefix.begin : beginRange[0].key;
}
// Determine how far to extend this range at the end
auto endRange = keys[1].get();
bool hasEnd = endRange.size() >= 1 && endRange[0].key.startsWith(mapPrefix) && endRange[0].key <= withPrefix.end;
bool hasNext = (endRange.size() == 2 && endRange[1].key.startsWith(mapPrefix)) ||
(endRange.size() == 1 && withPrefix.end < endRange[0].key && endRange[0].key.startsWith(mapPrefix));
Value existingValue = hasEnd ? endRange[0].value : LiteralStringRef("");
bool valueMatches = value == existingValue;
KeyRange conflictRange = KeyRangeRef(hasBegin ? beginRange[0].key : mapPrefix, withPrefix.begin);
if (!conflictRange.empty())
tr->addReadConflictRange(conflictRange);
conflictRange = KeyRangeRef(hasEnd ? endRange[0].key : mapPrefix,
hasNext ? keyAfter(endRange.end()[-1].key) : strinc(mapPrefix));
if (!conflictRange.empty())
tr->addReadConflictRange(conflictRange);
state Key endKey;
state Value endValue;
// Case 1: Coalesce completely with the following range
if (hasNext && endRange.end()[-1].key <= maxWithPrefix.end && valueMatches) {
endKey = endRange.end()[-1].key;
endValue = endRange.end()[-1].value;
}
// Case 2: Coalesce with the following range only up to the end of maxRange
else if (valueMatches) {
endKey = maxWithPrefix.end;
endValue = existingValue;
}
// Case 3: Don't coalesce
else {
endKey = withPrefix.end;
endValue = existingValue;
}
tr->clear(KeyRangeRef(beginKey, endKey));
ASSERT(value != endValue || endKey == maxWithPrefix.end);
tr->set(beginKey, value);
tr->set(endKey, endValue);
return Void();
}
Future<Void> krmSetRangeCoalescing(Transaction* const& tr,
Key const& mapPrefix,
KeyRange const& range,
KeyRange const& maxRange,
Value const& value) {
return krmSetRangeCoalescing_(tr, mapPrefix, range, maxRange, value);
}
Future<Void> krmSetRangeCoalescing(Reference<ReadYourWritesTransaction> const& tr,
Key const& mapPrefix,
KeyRange const& range,
KeyRange const& maxRange,
Value const& value) {
return holdWhile(tr, krmSetRangeCoalescing_(tr.getPtr(), mapPrefix, range, maxRange, value));
}