result_t MongoCollection::getCollection(exlib::string name,
obj_ptr<MongoCollection_base>& retVal)
{
obj_ptr<MongoDB> db(m_db);
if (!db)
return CHECK_ERROR(CALL_E_INVALID_CALL);
exlib::string nsStr(m_ns);
exlib::string nameStr(m_name);
nsStr += '.';
nsStr.append(name);
nameStr += '.';
nameStr.append(name);
retVal = new MongoCollection(db, nsStr, nameStr);
return 0;
}
UpdateResult _updateObjectsNEW( bool su,
const char* ns,
const BSONObj& updateobj,
const BSONObj& patternOrig,
bool upsert,
bool multi,
bool logop ,
OpDebug& debug,
RemoveSaver* rs,
bool fromMigrate,
const QueryPlanSelectionPolicy& planPolicy,
bool forReplication ) {
// TODO
// + Separate UpdateParser from UpdateRunner (the latter should be "stage-y")
// + All the yield and deduplicate logic would move to the query stage
// portion of it
//
// + Replication related
// + fast path for update for query by _id
// + support for relaxing viable path constraint in replication
//
// + Field Management
// + Force all upsert to contain _id
// + Prevent changes to immutable fields (_id, and those mentioned by sharding)
//
// + Yiedling related
// + $atomic support (or better, support proper yielding if not)
// + page fault support
debug.updateobj = updateobj;
NamespaceDetails* d = nsdetails( ns );
NamespaceDetailsTransient* nsdt = &NamespaceDetailsTransient::get( ns );
// TODO: Put this logic someplace central and check based on constants (maybe using the
// list of actually excluded config collections, and not global for the config db).
NamespaceString nsStr( ns );
// Should the modifiers validdate their embedded docs via okForStorage
bool shouldValidate = true;
// Config db docs shouldn't get checked for valid field names since the shard key can have
// a dot (".") in it. Therefore we disable validation for storage.
if ( nsStr.db() == "config" ) {
LOG(0) << "disabling okForStorage on config db";
shouldValidate = false;
}
UpdateDriver::Options opts;
opts.multi = multi;
opts.upsert = upsert;
opts.logOp = logop;
opts.modOptions = ModifierInterface::Options( forReplication, shouldValidate );
UpdateDriver driver( opts );
// TODO: This copies the index keys, but we may not actually need to.
Status status = driver.parse( nsdt->indexKeys(), updateobj );
if ( !status.isOK() ) {
uasserted( 16840, status.reason() );
}
shared_ptr<Cursor> cursor = getOptimizedCursor( ns, patternOrig, BSONObj(), planPolicy );
// If the update was marked with '$isolated' (a.k.a '$atomic'), we are not allowed to
// yield while evaluating the update loop below.
//
// TODO: Old code checks this repeatedly within the update loop. Is that necessary? It seems
// that once atomic should be always atomic.
const bool canYield =
cursor->ok() &&
cursor->matcher() &&
cursor->matcher()->docMatcher().atomic();
// The 'cursor' the optimizer gave us may contain query plans that generate duplicate
// diskloc's. We set up here the mechanims that will prevent us from processing those
// twice if we see them. We also set up a 'ClientCursor' so that we can support
// yielding.
//
// TODO: Is it valid to call this on a non-ok cursor?
const bool dedupHere = cursor->autoDedup();
//
// We'll start assuming we have one or more documents for this update. (Othwerwise,
// we'll fallback to upserting.)
//
// We record that this will not be an upsert, in case a mod doesn't want to be applied
// when in strict update mode.
driver.setContext( ModifierInterface::ExecInfo::UPDATE_CONTEXT );
// Let's fetch each of them and pipe them through the update expression, making sure to
// keep track of the necessary stats. Recall that we'll be pulling documents out of
// cursors and some of them do not deduplicate the entries they generate. We have
// deduping logic in here, too -- for now.
unordered_set<DiskLoc, DiskLoc::Hasher> seenLocs;
int numUpdated = 0;
debug.nscanned = 0;
Client& client = cc();
mutablebson::Document doc;
// If we are going to be yielding, we will need a ClientCursor scoped to this loop. We
// only loop as long as the underlying cursor is OK.
for ( auto_ptr<ClientCursor> clientCursor; cursor->ok(); ) {
// If we haven't constructed a ClientCursor, and if the client allows us to throw
// page faults, and if we are referring to a location that is likely not in
// physical memory, then throw a PageFaultException. The entire operation will be
// restarted.
if ( clientCursor.get() == NULL &&
client.allowedToThrowPageFaultException() &&
!cursor->currLoc().isNull() &&
!cursor->currLoc().rec()->likelyInPhysicalMemory() ) {
// We should never throw a PFE if we have already updated items.
dassert(numUpdated == 0);
throw PageFaultException( cursor->currLoc().rec() );
}
if ( !canYield && debug.nscanned != 0 ) {
// We are permitted to yield. To do so we need a ClientCursor, so create one
// now if we have not yet done so.
if ( !clientCursor.get() )
clientCursor.reset(
new ClientCursor( QueryOption_NoCursorTimeout, cursor, ns ) );
// Ask the client cursor to yield. We get two bits of state back: whether or not
// we yielded, and whether or not we correctly recovered from yielding.
bool yielded = false;
const bool recovered = clientCursor->yieldSometimes(
ClientCursor::WillNeed, &yielded );
// If we couldn't recover from the yield, or if the cursor died while we were
// yielded, get out of the update loop right away. We don't need to reset
// 'clientCursor' since we are leaving the scope.
if ( !recovered || !cursor->ok() )
break;
if ( yielded ) {
// Details about our namespace may have changed while we were yielded, so
// we re-acquire them here. If we can't do so, escape the update
// loop. Otherwise, refresh the driver so that it knows about what is
// currently indexed.
d = nsdetails( ns );
if ( !d )
break;
nsdt = &NamespaceDetailsTransient::get( ns );
// TODO: This copies the index keys, but it may not need to do so.
driver.refreshIndexKeys( nsdt->indexKeys() );
}
}
// Let's fetch the next candidate object for this update.
Record* r = cursor->_current();
DiskLoc loc = cursor->currLoc();
const BSONObj oldObj = loc.obj();
// We count how many documents we scanned even though we may skip those that are
// deemed duplicated. The final 'numUpdated' and 'nscanned' numbers may differ for
// that reason.
debug.nscanned++;
// Skips this document if it:
// a) doesn't match the query portion of the update
// b) was deemed duplicate by the underlying cursor machinery
//
// Now, if we are going to update the document,
// c) we don't want to do so while the cursor is at it, as that may invalidate
// the cursor. So, we advance to next document, before issuing the update.
MatchDetails matchDetails;
matchDetails.requestElemMatchKey();
if ( !cursor->currentMatches( &matchDetails ) ) {
// a)
cursor->advance();
continue;
}
else if ( cursor->getsetdup( loc ) && dedupHere ) {
// b)
cursor->advance();
continue;
}
else if (driver.dollarModMode() && multi) {
// c)
cursor->advance();
if ( dedupHere ) {
if ( seenLocs.count( loc ) ) {
continue;
}
}
// There are certain kind of cursors that hold multiple pointers to data
// underneath. $or cursors is one example. In a $or cursor, it may be the case
// that when we did the last advance(), we finished consuming documents from
// one of $or child and started consuming the next one. In that case, it is
// possible that the last document of the previous child is the same as the
// first document of the next (see SERVER-5198 and jstests/orp.js).
//
// So we advance the cursor here until we see a new diskloc.
//
// Note that we won't be yielding, and we may not do so for a while if we find
// a particularly duplicated sequence of loc's. That is highly unlikely,
// though. (See SERVER-5725, if curious, but "stage" based $or will make that
// ticket moot).
while( cursor->ok() && loc == cursor->currLoc() ) {
cursor->advance();
}
}
// For some (unfortunate) historical reasons, not all cursors would be valid after
// a write simply because we advanced them to a document not affected by the write.
// To protect in those cases, not only we engaged in the advance() logic above, but
// we also tell the cursor we're about to write a document that we've just seen.
// prepareToTouchEarlierIterate() requires calling later
// recoverFromTouchingEarlierIterate(), so we make a note here to do so.
bool touchPreviousDoc = multi && cursor->ok();
if ( touchPreviousDoc ) {
if ( clientCursor.get() )
clientCursor->setDoingDeletes( true );
cursor->prepareToTouchEarlierIterate();
}
// Ask the driver to apply the mods. It may be that the driver can apply those "in
// place", that is, some values of the old document just get adjusted without any
// change to the binary layout on the bson layer. It may be that a whole new
// document is needed to accomodate the new bson layout of the resulting document.
doc.reset( oldObj, mutablebson::Document::kInPlaceEnabled );
BSONObj logObj;
StringData matchedField = matchDetails.hasElemMatchKey() ?
matchDetails.elemMatchKey():
StringData();
status = driver.update( matchedField, &doc, &logObj );
if ( !status.isOK() ) {
uasserted( 16837, status.reason() );
}
// If the driver applied the mods in place, we can ask the mutable for what
// changed. We call those changes "damages". :) We use the damages to inform the
// journal what was changed, and then apply them to the original document
// ourselves. If, however, the driver applied the mods out of place, we ask it to
// generate a new, modified document for us. In that case, the file manager will
// take care of the journaling details for us.
//
// This code flow is admittedly odd. But, right now, journaling is baked in the file
// manager. And if we aren't using the file manager, we have to do jounaling
// ourselves.
bool objectWasChanged = false;
BSONObj newObj;
const char* source = NULL;
mutablebson::DamageVector damages;
bool inPlace = doc.getInPlaceUpdates(&damages, &source);
if ( inPlace && !damages.empty() && !driver.modsAffectIndices() ) {
d->paddingFits();
// All updates were in place. Apply them via durability and writing pointer.
mutablebson::DamageVector::const_iterator where = damages.begin();
const mutablebson::DamageVector::const_iterator end = damages.end();
for( ; where != end; ++where ) {
const char* sourcePtr = source + where->sourceOffset;
void* targetPtr = getDur().writingPtr(
const_cast<char*>(oldObj.objdata()) + where->targetOffset,
where->size);
std::memcpy(targetPtr, sourcePtr, where->size);
}
newObj = oldObj;
debug.fastmod = true;
objectWasChanged = true;
}
else {
// The updates were not in place. Apply them through the file manager.
newObj = doc.getObject();
DiskLoc newLoc = theDataFileMgr.updateRecord(ns,
d,
nsdt,
r,
loc,
newObj.objdata(),
newObj.objsize(),
debug);
// If we've moved this object to a new location, make sure we don't apply
// that update again if our traversal picks the objecta again.
//
// We also take note that the diskloc if the updates are affecting indices.
// Chances are that we're traversing one of them and they may be multi key and
// therefore duplicate disklocs.
if ( newLoc != loc || driver.modsAffectIndices() ) {
seenLocs.insert( newLoc );
}
objectWasChanged = true;
}
// Log Obj
if ( logop ) {
if ( !logObj.isEmpty() ) {
BSONObj idQuery = driver.makeOplogEntryQuery(newObj, multi);
logOp("u", ns, logObj , &idQuery, 0, fromMigrate, &newObj);
}
}
// If we applied any in-place updates, or asked the DataFileMgr to write for us,
// then count this as an update.
if (objectWasChanged)
numUpdated++;
if (!multi) {
break;
}
// If we used the cursor mechanism that prepares an earlier seen document for a
// write we need to tell such mechanisms that the write is over.
if ( touchPreviousDoc ) {
cursor->recoverFromTouchingEarlierIterate();
}
getDur().commitIfNeeded();
}
if (numUpdated > 0) {
return UpdateResult( true /* updated existing object(s) */,
driver.dollarModMode() /* $mod or obj replacement */,
numUpdated /* # of docments update */,
BSONObj() );
}
else if (numUpdated == 0 && !upsert) {
return UpdateResult( false /* no object updated */,
driver.dollarModMode() /* $mod or obj replacement */,
0 /* no updates */,
BSONObj() );
}
//
// We haven't succeeded updating any existing document but upserts are allowed.
//
// If this is a $mod base update, we need to generate a document by examining the
// query and the mods. Otherwise, we can use the object replacement sent by the user
// update command that was parsed by the driver before.
BSONObj oldObj;
if ( *updateobj.firstElementFieldName() == '$' ) {
if ( !driver.createFromQuery( patternOrig, &oldObj ) ) {
uasserted( 16835, "cannot create object to update" );
}
debug.fastmodinsert = true;
}
else {
// Copy the _id
if (patternOrig.hasElement("_id")) {
oldObj = patternOrig.getField("_id").wrap();
}
debug.upsert = true;
}
// Since this is an upsert, we will be oplogging it as an insert. We don't
// need the driver's help to build the oplog record, then. We also set the
// context of the update driver to an "upsert". Some mods may only work in that
// context (e.g. $setOnInsert).
driver.setLogOp( false );
driver.setContext( ModifierInterface::ExecInfo::INSERT_CONTEXT );
doc.reset( oldObj, mutablebson::Document::kInPlaceDisabled );
status = driver.update( StringData(), &doc, NULL /* no oplog record */);
if ( !status.isOK() ) {
uasserted( 16836, status.reason() );
}
BSONObj newObj = doc.getObject();
theDataFileMgr.insertWithObjMod( ns, newObj, false, su );
if ( logop ) {
logOp( "i", ns, newObj, 0, 0, fromMigrate, &newObj );
}
return UpdateResult( false /* updated a non existing document */,
driver.dollarModMode() /* $mod or obj replacement? */,
1 /* count of updated documents */,
newObj /* object that was upserted */ );
}
