void RecordStoreV1Base::deleteRecord(OperationContext* txn, const RecordId& rid) {
const DiskLoc dl = DiskLoc::fromRecordId(rid);
MmapV1RecordHeader* todelete = recordFor(dl);
invariant(todelete->netLength() >= 4); // this is required for defensive code
/* remove ourself from the record next/prev chain */
{
if (todelete->prevOfs() != DiskLoc::NullOfs) {
DiskLoc prev = getPrevRecordInExtent(txn, dl);
MmapV1RecordHeader* prevRecord = recordFor(prev);
txn->recoveryUnit()->writingInt(prevRecord->nextOfs()) = todelete->nextOfs();
}
if (todelete->nextOfs() != DiskLoc::NullOfs) {
DiskLoc next = getNextRecord(txn, dl);
MmapV1RecordHeader* nextRecord = recordFor(next);
txn->recoveryUnit()->writingInt(nextRecord->prevOfs()) = todelete->prevOfs();
}
}
/* remove ourself from extent pointers */
{
DiskLoc extentLoc = todelete->myExtentLoc(dl);
Extent* e = _getExtent(txn, extentLoc);
if (e->firstRecord == dl) {
txn->recoveryUnit()->writing(&e->firstRecord);
if (todelete->nextOfs() == DiskLoc::NullOfs)
e->firstRecord.Null();
else
e->firstRecord.set(dl.a(), todelete->nextOfs());
}
if (e->lastRecord == dl) {
txn->recoveryUnit()->writing(&e->lastRecord);
if (todelete->prevOfs() == DiskLoc::NullOfs)
e->lastRecord.Null();
else
e->lastRecord.set(dl.a(), todelete->prevOfs());
}
}
/* add to the free list */
{
_details->incrementStats(txn, -1 * todelete->netLength(), -1);
if (_isSystemIndexes) {
/* temp: if in system.indexes, don't reuse, and zero out: we want to be
careful until validated more, as IndexDetails has pointers
to this disk location. so an incorrectly done remove would cause
a lot of problems.
*/
memset(txn->recoveryUnit()->writingPtr(todelete, todelete->lengthWithHeaders()),
0,
todelete->lengthWithHeaders());
} else {
// this is defensive so we can detect if we are still using a location
// that was deleted
memset(txn->recoveryUnit()->writingPtr(todelete->data(), 4), 0xee, 4);
addDeletedRec(txn, dl);
}
}
}
void SimpleRecordStoreV1::_compactExtent(OperationContext* txn,
const DiskLoc extentLoc,
int extentNumber,
RecordStoreCompactAdaptor* adaptor,
const CompactOptions* compactOptions,
CompactStats* stats) {
log() << "compact begin extent #" << extentNumber << " for namespace " << _ns << " "
<< extentLoc;
unsigned oldObjSize = 0; // we'll report what the old padding was
unsigned oldObjSizeWithPadding = 0;
Extent* const sourceExtent = _extentManager->getExtent(extentLoc);
sourceExtent->assertOk();
fassert(17437, sourceExtent->validates(extentLoc));
{
// The next/prev MmapV1RecordHeader pointers within the Extent might not be in order so we
// first page in the whole Extent sequentially.
// TODO benchmark on slow storage to verify this is measurably faster.
log() << "compact paging in len=" << sourceExtent->length / 1000000.0 << "MB" << endl;
Timer t;
size_t length = sourceExtent->length;
touch_pages(reinterpret_cast<const char*>(sourceExtent), length);
int ms = t.millis();
if (ms > 1000)
log() << "compact end paging in " << ms << "ms "
<< sourceExtent->length / 1000000.0 / t.seconds() << "MB/sec" << endl;
}
{
// Move each MmapV1RecordHeader out of this extent and insert it in to the "new" extents.
log() << "compact copying records" << endl;
long long totalNetSize = 0;
long long nrecords = 0;
DiskLoc nextSourceLoc = sourceExtent->firstRecord;
while (!nextSourceLoc.isNull()) {
txn->checkForInterrupt();
WriteUnitOfWork wunit(txn);
MmapV1RecordHeader* recOld = recordFor(nextSourceLoc);
RecordData oldData = recOld->toRecordData();
nextSourceLoc = getNextRecordInExtent(txn, nextSourceLoc);
if (compactOptions->validateDocuments && !adaptor->isDataValid(oldData)) {
// object is corrupt!
log() << "compact removing corrupt document!";
stats->corruptDocuments++;
} else {
// How much data is in the record. Excludes padding and MmapV1RecordHeader headers.
const unsigned rawDataSize = adaptor->dataSize(oldData);
nrecords++;
oldObjSize += rawDataSize;
oldObjSizeWithPadding += recOld->netLength();
// Allocation sizes include the headers and possibly some padding.
const unsigned minAllocationSize = rawDataSize + MmapV1RecordHeader::HeaderSize;
unsigned allocationSize = minAllocationSize;
switch (compactOptions->paddingMode) {
case CompactOptions::NONE: // default padding
if (shouldPadInserts()) {
allocationSize = quantizeAllocationSpace(minAllocationSize);
}
break;
case CompactOptions::PRESERVE: // keep original padding
allocationSize = recOld->lengthWithHeaders();
break;
case CompactOptions::MANUAL: // user specified how much padding to use
allocationSize = compactOptions->computeRecordSize(minAllocationSize);
if (allocationSize < minAllocationSize ||
allocationSize > BSONObjMaxUserSize / 2) {
allocationSize = minAllocationSize;
}
break;
}
invariant(allocationSize >= minAllocationSize);
// Copy the data to a new record. Because we orphaned the record freelist at the
// start of the compact, this insert will allocate a record in a new extent.
// See the comment in compact() for more details.
CompactDocWriter writer(recOld, rawDataSize, allocationSize);
StatusWith<RecordId> status = insertRecordWithDocWriter(txn, &writer);
uassertStatusOK(status.getStatus());
const MmapV1RecordHeader* newRec =
recordFor(DiskLoc::fromRecordId(status.getValue()));
invariant(unsigned(newRec->netLength()) >= rawDataSize);
totalNetSize += newRec->netLength();
// Tells the caller that the record has been moved, so it can do things such as
// add it to indexes.
adaptor->inserted(newRec->toRecordData(), status.getValue());
}
// Remove the old record from the linked list of records withing the sourceExtent.
// The old record is not added to the freelist as we will be freeing the whole
// extent at the end.
*txn->recoveryUnit()->writing(&sourceExtent->firstRecord) = nextSourceLoc;
if (nextSourceLoc.isNull()) {
// Just moved the last record out of the extent. Mark extent as empty.
*txn->recoveryUnit()->writing(&sourceExtent->lastRecord) = DiskLoc();
} else {
MmapV1RecordHeader* newFirstRecord = recordFor(nextSourceLoc);
txn->recoveryUnit()->writingInt(newFirstRecord->prevOfs()) = DiskLoc::NullOfs;
}
// Adjust the stats to reflect the removal of the old record. The insert above
// handled adjusting the stats for the new record.
_details->incrementStats(txn, -(recOld->netLength()), -1);
wunit.commit();
}
// The extent must now be empty.
invariant(sourceExtent->firstRecord.isNull());
invariant(sourceExtent->lastRecord.isNull());
// We are still the first extent, but we must not be the only extent.
invariant(_details->firstExtent(txn) == extentLoc);
invariant(_details->lastExtent(txn) != extentLoc);
// Remove the newly emptied sourceExtent from the extent linked list and return it to
// the extent manager.
WriteUnitOfWork wunit(txn);
const DiskLoc newFirst = sourceExtent->xnext;
_details->setFirstExtent(txn, newFirst);
*txn->recoveryUnit()->writing(&_extentManager->getExtent(newFirst)->xprev) = DiskLoc();
_extentManager->freeExtent(txn, extentLoc);
wunit.commit();
{
const double oldPadding = oldObjSize ? double(oldObjSizeWithPadding) / oldObjSize
: 1.0; // defining 0/0 as 1 for this.
log() << "compact finished extent #" << extentNumber << " containing " << nrecords
<< " documents (" << totalNetSize / (1024 * 1024.0) << "MB)"
<< " oldPadding: " << oldPadding;
}
}
}
void initializeV1RS(OperationContext* opCtx,
const LocAndSize* records,
const LocAndSize* drecs,
const LocAndSize* legacyGrabBag,
DummyExtentManager* em,
DummyRecordStoreV1MetaData* md) {
invariant(records || drecs); // if both are NULL nothing is being created...
// Need to start with a blank slate
invariant(em->numFiles() == 0);
invariant(md->firstExtent(opCtx).isNull());
// pre-allocate extents (even extents that aren't part of this RS)
{
typedef std::map<int, size_t> ExtentSizes;
ExtentSizes extentSizes;
accumulateExtentSizeRequirements(records, &extentSizes);
accumulateExtentSizeRequirements(drecs, &extentSizes);
accumulateExtentSizeRequirements(legacyGrabBag, &extentSizes);
invariant(!extentSizes.empty());
const int maxExtent = extentSizes.rbegin()->first;
for (int i = 0; i <= maxExtent; i++) {
const size_t size = extentSizes.count(i) ? extentSizes[i] : 0;
const DiskLoc loc = em->allocateExtent(opCtx, md->isCapped(), size, 0);
// This function and assertState depend on these details of DummyExtentManager
invariant(loc.a() == i);
invariant(loc.getOfs() == 0);
}
// link together extents that should be part of this RS
md->setFirstExtent(opCtx, DiskLoc(extentSizes.begin()->first, 0));
md->setLastExtent(opCtx, DiskLoc(extentSizes.rbegin()->first, 0));
for (ExtentSizes::iterator it = extentSizes.begin(); boost::next(it) != extentSizes.end();
/* ++it */) {
const int a = it->first;
++it;
const int b = it->first;
em->getExtent(DiskLoc(a, 0))->xnext = DiskLoc(b, 0);
em->getExtent(DiskLoc(b, 0))->xprev = DiskLoc(a, 0);
}
// This signals "done allocating new extents".
if (md->isCapped())
md->setDeletedListEntry(opCtx, 1, DiskLoc());
}
if (records && !records[0].loc.isNull()) {
int recIdx = 0;
DiskLoc extLoc = md->firstExtent(opCtx);
while (!extLoc.isNull()) {
Extent* ext = em->getExtent(extLoc);
int prevOfs = DiskLoc::NullOfs;
while (extLoc.a() == records[recIdx].loc.a()) { // for all records in this extent
const DiskLoc loc = records[recIdx].loc;
const int size = records[recIdx].size;
;
invariant(size >= MmapV1RecordHeader::HeaderSize);
md->incrementStats(opCtx, size - MmapV1RecordHeader::HeaderSize, 1);
if (ext->firstRecord.isNull())
ext->firstRecord = loc;
MmapV1RecordHeader* rec = em->recordForV1(loc);
rec->lengthWithHeaders() = size;
rec->extentOfs() = 0;
rec->prevOfs() = prevOfs;
prevOfs = loc.getOfs();
const DiskLoc nextLoc = records[recIdx + 1].loc;
if (nextLoc.a() == loc.a()) { // if next is in same extent
rec->nextOfs() = nextLoc.getOfs();
} else {
rec->nextOfs() = DiskLoc::NullOfs;
ext->lastRecord = loc;
}
recIdx++;
}
extLoc = ext->xnext;
}
invariant(records[recIdx].loc.isNull());
}
if (drecs && !drecs[0].loc.isNull()) {
int drecIdx = 0;
DiskLoc* prevNextPtr = NULL;
int lastBucket = -1;
while (!drecs[drecIdx].loc.isNull()) {
const DiskLoc loc = drecs[drecIdx].loc;
const int size = drecs[drecIdx].size;
invariant(size >= MmapV1RecordHeader::HeaderSize);
const int bucket = RecordStoreV1Base::bucket(size);
if (md->isCapped()) {
// All drecs form a single list in bucket 0
if (prevNextPtr == NULL) {
md->setDeletedListEntry(opCtx, 0, loc);
} else {
*prevNextPtr = loc;
}
if (loc.a() < md->capExtent().a() &&
drecs[drecIdx + 1].loc.a() == md->capExtent().a()) {
// Bucket 1 is known as cappedLastDelRecLastExtent
md->setDeletedListEntry(opCtx, 1, loc);
}
} else if (bucket != lastBucket) {
invariant(bucket > lastBucket); // if this fails, drecs weren't sorted by bucket
md->setDeletedListEntry(opCtx, bucket, loc);
lastBucket = bucket;
} else {
*prevNextPtr = loc;
}
DeletedRecord* drec = &em->recordForV1(loc)->asDeleted();
drec->lengthWithHeaders() = size;
drec->extentOfs() = 0;
drec->nextDeleted() = DiskLoc();
prevNextPtr = &drec->nextDeleted();
drecIdx++;
}
}
if (legacyGrabBag && !legacyGrabBag[0].loc.isNull()) {
invariant(!md->isCapped()); // capped should have an empty legacy grab bag.
int grabBagIdx = 0;
DiskLoc* prevNextPtr = NULL;
while (!legacyGrabBag[grabBagIdx].loc.isNull()) {
const DiskLoc loc = legacyGrabBag[grabBagIdx].loc;
const int size = legacyGrabBag[grabBagIdx].size;
invariant(size >= MmapV1RecordHeader::HeaderSize);
if (grabBagIdx == 0) {
md->setDeletedListLegacyGrabBag(opCtx, loc);
} else {
*prevNextPtr = loc;
}
DeletedRecord* drec = &em->recordForV1(loc)->asDeleted();
drec->lengthWithHeaders() = size;
drec->extentOfs() = 0;
drec->nextDeleted() = DiskLoc();
prevNextPtr = &drec->nextDeleted();
grabBagIdx++;
}
}
// Make sure we set everything up as requested.
assertStateV1RS(opCtx, records, drecs, legacyGrabBag, em, md);
}
