bool get_field(doid_t do_id, const Field* field, val_t &value)
{
m_log->trace() << "Getting field on obj-" << do_id << endl;
YAML::Node document;
if(!load(do_id, document))
{
return false;
}
// Get the fields from the file that are not being updated
YAML::Node node = document["fields"][field->get_name()];
if(!node.IsDefined() || node.IsNull())
{
return false;
}
m_log->trace() << "Found requested field: " + field->get_name() << endl;
value = read_yaml_field(field, node, do_id);
if(value.size() > 0)
{
return true;
}
return false;
}
bool get_fields(doid_t do_id, const vector<const Field*> &fields, map_t &values)
{
m_log->trace() << "Getting fields on obj-" << do_id << endl;
YAML::Node document;
if(!load(do_id, document))
{
return false;
}
// Get the fields from the file that are not being updated
for(auto it = fields.begin(); it != fields.end(); ++it)
{
const Field* field = *it;
m_log->trace() << "Searching for field: " << field->get_name() << endl;
YAML::Node existing = document["fields"];
for(auto it2 = existing.begin(); it2 != existing.end(); ++it2)
{
if(it2->first.as<string>() == field->get_name())
{
vector<uint8_t> value = read_yaml_field(field, it2->second, do_id);
if(value.size() > 0)
{
values[*it] = value;
m_log->trace() << "Found requested field: " + field->get_name() << endl;
}
}
}
}
return true;
}
// This is used when the monotonic counter is exhausted:
doid_t assign_doid_reuse(DBClientBase *client)
{
BSONObj result;
bool success = client->runCommand(
m_db,
BSON("findandmodify" << "astron.globals" <<
"query" << BSON(
"_id" << "GLOBALS" <<
"doid.free.0" << BSON("$exists" << true)
) <<
"update" << BSON(
"$pop" << BSON("doid.free" << -1)
)), result);
// If the findandmodify command failed, the document either doesn't
// exist, or we ran out of reusable doids.
if(!success || result["value"].isNull()) {
m_log->error() << "Could not allocate a reused DOID!" << endl;
return INVALID_DO_ID;
}
m_log->trace() << "assign_doid_reuse: got globals element: "
<< result << endl;
// Otherwise, use the first one:
doid_t doid;
const BSONElement &element = result["value"]["doid"]["free"];
if(sizeof(doid) == sizeof(long long)) {
doid = element.Array()[0].Long();
} else if(sizeof(doid) == sizeof(int)) {
doid = element.Array()[0].Int();
}
return doid;
}
doid_t assign_doid_monotonic(DBClientBase *client)
{
BSONObj result;
bool success = client->runCommand(
m_db,
BSON("findandmodify" << "astron.globals" <<
"query" << BSON(
"_id" << "GLOBALS" <<
"doid.monotonic" << GTE << m_min_id <<
"doid.monotonic" << LTE << m_max_id
) <<
"update" << BSON(
"$inc" << BSON("doid.monotonic" << 1)
)), result);
// If the findandmodify command failed, the document either doesn't
// exist, or we ran out of monotonic doids.
if(!success || result["value"].isNull()) {
return INVALID_DO_ID;
}
m_log->trace() << "assign_doid_monotonic: got globals element: "
<< result << endl;
doid_t doid;
const BSONElement &element = result["value"]["doid"]["monotonic"];
if(sizeof(doid) == sizeof(long long)) {
doid = element.Long();
} else if(sizeof(doid) == sizeof(int)) {
doid = element.Int();
}
return doid;
}
void handle_delete(DBClientBase *client, DBOperation *operation)
{
BSONObj result;
bool success;
try {
success = client->runCommand(
m_db,
BSON("findandmodify" << "astron.objects" <<
"query" << BSON(
"_id" << operation->doid()) <<
"remove" << true),
result);
} catch(mongo::DBException &e) {
m_log->error() << "Unexpected error while deleting "
<< operation->doid() << ": " << e.what() << endl;
operation->on_failure();
return;
}
m_log->trace() << "handle_delete: got response: "
<< result << endl;
// If the findandmodify command failed, there wasn't anything there
// to delete in the first place.
if(!success || result["value"].isNull()) {
m_log->error() << "Tried to delete non-existent doid "
<< operation->doid() << endl;
operation->on_failure();
return;
}
free_doid(client, operation->doid());
operation->on_complete();
}
void set_field(doid_t do_id, const Field* field, const val_t &value)
{
m_log->trace() << "Setting field on obj-" << do_id << endl;
YAML::Node document;
if(!load(do_id, document))
{
return;
}
// Get the fields from the file that are not being updated
const Class* dcc = g_dcf->get_class_by_name(document["class"].as<string>());
ObjectData dbo(dcc->get_id());
YAML::Node existing = document["fields"];
for(auto it = existing.begin(); it != existing.end(); ++it)
{
const Field* field = dcc->get_field_by_name(it->first.as<string>());
if(!field)
{
m_log->warning() << "Field '" << it->first.as<string>()
<< "', loaded from '" << filename(do_id)
<< "', does not exist." << endl;
continue;
}
vector<uint8_t> value = read_yaml_field(field, it->second, do_id);
if(value.size() > 0)
{
dbo.fields[field] = value;
}
}
dbo.fields[field] = value;
write_yaml_object(do_id, dcc, dbo);
}
const Class* get_class(doid_t do_id)
{
m_log->trace() << "Getting dclass of obj-" << do_id << endl;
// Open file for object
YAML::Node document;
if(!load(do_id, document))
{
return NULL;
}
return g_dcf->get_class_by_name(document["class"].as<string>());
}
void handle_create(DBClientBase *client, DBOperation *operation)
{
// First, let's convert the requested object into BSON; this way, if
// a failure happens, it happens before we waste a doid.
BSONObjBuilder fields;
try {
for(auto it = operation->set_fields().begin();
it != operation->set_fields().end();
++it) {
DatagramPtr dg = Datagram::create();
dg->add_data(it->second);
DatagramIterator dgi(dg);
fields << it->first->get_name()
<< bamboo2bson(it->first->get_type(), dgi)["_"];
}
} catch(mongo::DBException &e) {
m_log->error() << "While formatting "
<< operation->dclass()->get_name()
<< " for insertion: " << e.what() << endl;
operation->on_failure();
return;
}
doid_t doid = assign_doid(client);
if(doid == INVALID_DO_ID) {
// The error will already have been emitted at this point, so
// all that's left for us to do is fail silently:
operation->on_failure();
return;
}
BSONObj b = BSON("_id" << doid <<
"dclass" << operation->dclass()->get_name() <<
"fields" << fields.obj());
m_log->trace() << "Inserting new " << operation->dclass()->get_name()
<< "(" << doid << "): " << b << endl;
try {
client->insert(m_obj_collection, b);
} catch(mongo::DBException &e) {
m_log->error() << "Cannot insert new "
<< operation->dclass()->get_name()
<< "(" << doid << "): " << e.what() << endl;
operation->on_failure();
return;
}
operation->on_complete(doid);
}
// This returns a DOID to the free list:
void free_doid(DBClientBase *client, doid_t doid)
{
m_log->trace() << "Returning doid " << doid << " to the free pool..." << endl;
try {
client->update(
m_global_collection,
BSON("_id" << "GLOBALS"),
BSON("$push" << BSON("doid.free" << doid)));
} catch(mongo::DBException &e) {
m_log->error() << "Could not return doid " << doid
<< " to free pool: " << e.what() << endl;
}
}
bool set_field_if_equals(doid_t do_id, const Field* field, const val_t &equal, val_t &value)
{
m_log->trace() << "Setting field if equal on obj-" << do_id << endl;
YAML::Node document;
if(!load(do_id, document))
{
value = vector<uint8_t>();
return false;
}
// Get current field values from the file
const Class* dcc = g_dcf->get_class_by_name(document["class"].as<string>());
ObjectData dbo(dcc->get_id());
YAML::Node existing = document["fields"];
for(auto it = existing.begin(); it != existing.end(); ++it)
{
const Field* field = dcc->get_field_by_name(it->first.as<string>());
if(!field)
{
m_log->warning() << "Field '" << it->first.as<string>()
<< "', loaded from '" << filename(do_id)
<< "', does not exist." << endl;
continue;
}
vector<uint8_t> value = read_yaml_field(field, it->second, do_id);
if(value.size() > 0)
{
dbo.fields[field] = value;
}
}
auto found = dbo.fields.find(field);
if(found == dbo.fields.end() || found->second != equal)
{
value = dbo.fields[field];
return false;
}
dbo.fields[field] = value;
write_yaml_object(do_id, dcc, dbo);
return true;
}
// Get a DBObjectSnapshot from a MongoDB BSON object; returns NULL if failure.
DBObjectSnapshot *format_snapshot(doid_t doid, const BSONObj &obj)
{
m_log->trace() << "Formatting database snapshot of " << doid << ": "
<< obj << endl;
try {
string dclass_name = obj["dclass"].String();
const dclass::Class *dclass = g_dcf->get_class_by_name(dclass_name);
if(!dclass) {
m_log->error() << "Encountered unknown database object: "
<< dclass_name << "(" << doid << ")" << endl;
return NULL;
}
BSONObj fields = obj["fields"].Obj();
DBObjectSnapshot *snap = new DBObjectSnapshot();
snap->m_dclass = dclass;
for(auto it = fields.begin(); it.more(); ++it) {
const char *name = (*it).fieldName();
const dclass::Field *field = dclass->get_field_by_name(name);
if(!field) {
m_log->warning() << "Encountered unexpected field " << name
<< " while formatting " << dclass_name
<< "(" << doid << "); ignored." << endl;
continue;
}
{
DatagramPtr dg = Datagram::create();
bson2bamboo(field->get_type(), *it, *dg);
snap->m_fields[field].resize(dg->size());
memcpy(snap->m_fields[field].data(), dg->get_data(), dg->size());
}
}
return snap;
} catch(mongo::DBException &e) {
m_log->error() << "Unexpected error while trying to format"
" database snapshot for " << doid << ": "
<< e.what() << endl;
return NULL;
}
}
bool get_object(doid_t do_id, ObjectData &dbo)
{
m_log->trace() << "Getting obj-" << do_id << " ..." << endl;
// Open file for object
YAML::Node document;
if(!load(do_id, document))
{
return false;
}
// Read object's DistributedClass
const Class* dcc = g_dcf->get_class_by_name(document["class"].as<string>());
dbo.dc_id = dcc->get_id();
// Read object's fields
YAML::Node fields = document["fields"];
for(auto it = fields.begin(); it != fields.end(); ++it)
{
const Field* field = dcc->get_field_by_name(it->first.as<string>());
if(!field)
{
m_log->warning() << "Field '" << it->first.as<string>()
<< "', loaded from '" << filename(do_id)
<< "', does not exist." << endl;
continue;
}
vector<uint8_t> value = read_yaml_field(field, it->second, do_id);
if(value.size() > 0)
{
dbo.fields[field] = value;
}
}
return true;
}
void handle_modify(DBClientBase *client, DBOperation *operation)
{
// First, we have to format our findandmodify.
BSONObjBuilder sets;
bool has_sets = false;
BSONObjBuilder unsets;
bool has_unsets = false;
for(auto it = operation->set_fields().begin();
it != operation->set_fields().end(); ++it) {
stringstream fieldname;
fieldname << "fields." << it->first->get_name();
if(it->second.empty()) {
unsets << fieldname.str() << true;
has_unsets = true;
} else {
DatagramPtr dg = Datagram::create();
dg->add_data(it->second);
DatagramIterator dgi(dg);
sets << fieldname.str() << bamboo2bson(it->first->get_type(), dgi)["_"];
has_sets = true;
}
}
BSONObjBuilder updates_b;
if(has_sets) {
updates_b << "$set" << sets.obj();
}
if(has_unsets) {
updates_b << "$unset" << unsets.obj();
}
BSONObj updates = updates_b.obj();
// Also format any criteria for the change:
BSONObjBuilder query_b;
query_b << "_id" << operation->doid();
for(auto it = operation->criteria_fields().begin();
it != operation->criteria_fields().end(); ++it) {
stringstream fieldname;
fieldname << "fields." << it->first->get_name();
if(it->second.empty()) {
query_b << fieldname.str() << BSON("$exists" << false);
} else {
DatagramPtr dg = Datagram::create();
dg->add_data(it->second);
DatagramIterator dgi(dg);
query_b << fieldname.str() << bamboo2bson(it->first->get_type(), dgi)["_"];
}
}
BSONObj query = query_b.obj();
m_log->trace() << "Performing updates to " << operation->doid()
<< ": " << updates << endl;
m_log->trace() << "Query is: " << query << endl;
BSONObj result;
bool success;
try {
success = client->runCommand(
m_db,
BSON("findandmodify" << "astron.objects"
<< "query" << query
<< "update" << updates),
result);
} catch(mongo::DBException &e) {
m_log->error() << "Unexpected error while modifying "
<< operation->doid() << ": " << e.what() << endl;
operation->on_failure();
return;
}
m_log->trace() << "Update result: " << result << endl;
BSONObj obj;
if(!success || result["value"].isNull()) {
// Okay, something didn't work right. If we had criteria, let's
// try to fetch the object without the criteria to see if it's a
// criteria mismatch or a missing DOID.
if(!operation->criteria_fields().empty()) {
try {
obj = client->findOne(m_obj_collection,
BSON("_id" << operation->doid()));
} catch(mongo::DBException &e) {
m_log->error() << "Unexpected error while modifying "
<< operation->doid() << ": " << e.what() << endl;
operation->on_failure();
return;
}
if(!obj.isEmpty()) {
// There's the problem. Now we can send back a snapshot:
DBObjectSnapshot *snap = format_snapshot(operation->doid(), obj);
if(snap && operation->verify_class(snap->m_dclass)) {
operation->on_criteria_mismatch(snap);
return;
} else {
// Something else weird happened with our snapshot;
// either the class wasn't recognized or it was the
// wrong class. Either way, an error has been logged,
// and we need to fail the operation.
operation->on_failure();
return;
}
}
}
// Nope, not that. We're missing the DOID.
m_log->error() << "Attempted to modify unknown DOID: "
<< operation->doid() << endl;
operation->on_failure();
return;
}
// If we've gotten to this point: Hooray! The change has gone
// through to the database.
// Let's, however, double-check our changes. (Specifically, we should
// run verify_class so that we know the frontend is happy with what
// kind of object we just modified.)
obj = result["value"].Obj();
try {
string dclass_name = obj["dclass"].String();
const dclass::Class *dclass = g_dcf->get_class_by_name(dclass_name);
if(!dclass) {
m_log->error() << "Encountered unknown database object: "
<< dclass_name << "(" << operation->doid() << ")" << endl;
} else if(operation->verify_class(dclass)) {
// Yep, it all checks out. Complete the operation:
operation->on_complete();
return;
}
} catch(mongo::DBException &e) { }
// If we've gotten here, something is seriously wrong. We've just
// mucked with an object without knowing the consequences! What have
// we done?! We've created an abomination in the database! Kill it!
// Kill it with fire!
// All we really can do to mitigate this is scream at the user (which
// the above verification has already done by now) and revert the
// object back to how it was when we found it.
// NOTE: This DOES have the potential for data loss, because we're
// wiping out any changes that conceivably could have happened
// between the findandmodify and now. In dev environments, (which we
// are probably in right now, if other components are making
// outlandish requests like this) this shouldn't be a huge issue.
m_log->trace() << "Reverting changes made to " << operation->doid() << endl;
try {
client->update(
m_obj_collection,
BSON("_id" << operation->doid()),
obj);
} catch(mongo::DBException &e) {
// Wow, we REALLY fail at life.
m_log->error() << "Could not revert corrupting changes to "
<< operation->doid() << ": " << e.what() << endl;
}
operation->on_failure();
}
bool set_fields_if_equals(doid_t do_id, const map_t &equals, map_t &values)
{
m_log->trace() << "Setting fields if equals on obj-" << do_id << endl;
YAML::Node document;
if(!load(do_id, document))
{
values.clear();
return false;
}
// Get current field values from the file
const Class* dcc = g_dcf->get_class_by_name(document["class"].as<string>());
ObjectData dbo(dcc->get_id());
YAML::Node existing = document["fields"];
for(auto it = existing.begin(); it != existing.end(); ++it)
{
const Field* field = dcc->get_field_by_name(it->first.as<string>());
if(!field)
{
m_log->warning() << "Field '" << it->first.as<string>()
<< "', loaded from '" << filename(do_id)
<< "', does not exist." << endl;
continue;
}
vector<uint8_t> value = read_yaml_field(field, it->second, do_id);
if(value.size() > 0)
{
dbo.fields[field] = value;
}
}
// Check if equals matches current values
bool fail = false;
for(auto it = equals.begin(); it != equals.end(); ++it)
{
auto found = dbo.fields.find(it->first);
if(found == dbo.fields.end())
{
values.erase(it->first);
fail = true;
}
else if(it->second != found->second)
{
values.erase(it->first);
fail = true;
}
}
// Return current values on failure
if(fail)
{
for(auto it = values.begin(); it != values.end(); ++it)
{
it->second = dbo.fields[it->first];
}
return false;
}
// Update existing values on success
for(auto it = values.begin(); it != values.end(); ++it)
{
dbo.fields[it->first] = it->second;
}
write_yaml_object(do_id, dcc, dbo);
return true;
}
