realm-js/object_store.cpp

424 lines
16 KiB
C++

////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// 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 "object_store.hpp"
#include <realm/group.hpp>
#include <realm/table.hpp>
#include <realm/link_view.hpp>
#include <realm/table_view.hpp>
#include <realm/util/assert.hpp>
#include <set>
#include <string.h>
using namespace realm;
using namespace std;
const char * const c_metadataTableName = "metadata";
const char * const c_versionColumnName = "version";
const size_t c_versionColumnIndex = 0;
const char * const c_primaryKeyTableName = "pk";
const char * const c_primaryKeyObjectClassColumnName = "pk_table";
const size_t c_primaryKeyObjectClassColumnIndex = 0;
const char * const c_primaryKeyPropertyNameColumnName = "pk_property";
const size_t c_primaryKeyPropertyNameColumnIndex = 1;
const size_t c_zeroRowIndex = 0;
const string c_object_table_prefix = "class_";
const size_t c_object_table_prefix_length = c_object_table_prefix.length();
const uint64_t ObjectStore::NotVersioned = numeric_limits<uint64_t>::max();
bool ObjectStore::has_metadata_tables(Group *group) {
return group->get_table(c_primaryKeyTableName) && group->get_table(c_metadataTableName);
}
bool ObjectStore::create_metadata_tables(Group *group) {
bool changed = false;
TableRef table = group->get_or_add_table(c_primaryKeyTableName);
if (table->get_column_count() == 0) {
table->add_column(type_String, c_primaryKeyObjectClassColumnName);
table->add_column(type_String, c_primaryKeyPropertyNameColumnName);
changed = true;
}
table = group->get_or_add_table(c_metadataTableName);
if (table->get_column_count() == 0) {
table->add_column(type_Int, c_versionColumnName);
// set initial version
table->add_empty_row();
table->set_int(c_versionColumnIndex, c_zeroRowIndex, ObjectStore::NotVersioned);
changed = true;
}
return changed;
}
uint64_t ObjectStore::get_schema_version(Group *group) {
TableRef table = group->get_table(c_metadataTableName);
if (!table || table->get_column_count() == 0) {
return ObjectStore::NotVersioned;
}
return table->get_int(c_versionColumnIndex, c_zeroRowIndex);
}
void ObjectStore::set_schema_version(Group *group, uint64_t version) {
TableRef table = group->get_or_add_table(c_metadataTableName);
table->set_int(c_versionColumnIndex, c_zeroRowIndex, version);
}
StringData ObjectStore::get_primary_key_for_object(Group *group, StringData object_type) {
TableRef table = group->get_table(c_primaryKeyTableName);
if (!table) {
return "";
}
size_t row = table->find_first_string(c_primaryKeyObjectClassColumnIndex, object_type);
if (row == not_found) {
return "";
}
return table->get_string(c_primaryKeyPropertyNameColumnIndex, row);
}
void ObjectStore::set_primary_key_for_object(Group *group, StringData object_type, StringData primary_key) {
TableRef table = group->get_table(c_primaryKeyTableName);
// get row or create if new object and populate
size_t row = table->find_first_string(c_primaryKeyObjectClassColumnIndex, object_type);
if (row == not_found && primary_key.size()) {
row = table->add_empty_row();
table->set_string(c_primaryKeyObjectClassColumnIndex, row, object_type);
}
// set if changing, or remove if setting to nil
if (primary_key.size() == 0) {
if (row != not_found) {
table->remove(row);
}
}
else {
table->set_string(c_primaryKeyPropertyNameColumnIndex, row, primary_key);
}
}
string ObjectStore::object_type_for_table_name(const string &table_name) {
if (table_name.size() >= c_object_table_prefix_length && table_name.compare(0, c_object_table_prefix_length, c_object_table_prefix) == 0) {
return table_name.substr(c_object_table_prefix_length, table_name.length() - c_object_table_prefix_length);
}
return string();
}
string ObjectStore::table_name_for_object_type(const string &object_type) {
return c_object_table_prefix + object_type;
}
TableRef ObjectStore::table_for_object_type(Group *group, StringData object_type) {
return group->get_table(table_name_for_object_type(object_type));
}
TableRef ObjectStore::table_for_object_type_create_if_needed(Group *group, const StringData &object_type, bool &created) {
return group->get_or_add_table(table_name_for_object_type(object_type), &created);
}
std::vector<std::string> ObjectStore::validate_schema(Group *group, ObjectSchema &target_schema) {
vector<string> validation_errors;
ObjectSchema table_schema(group, target_schema.name);
// check to see if properties are the same
for (auto& current_prop : table_schema.properties) {
auto target_prop = target_schema.property_for_name(current_prop.name);
if (!target_prop) {
validation_errors.push_back("Property '" + current_prop.name + "' is missing from latest object model.");
continue;
}
if (current_prop.type != target_prop->type) {
validation_errors.push_back("Property types for '" + target_prop->name + "' property do not match. " +
"Old type '" + string_for_property_type(current_prop.type) +
"', new type '" + string_for_property_type(target_prop->type) + "'");
continue;
}
if (current_prop.type == PropertyTypeObject || target_prop->type == PropertyTypeArray) {
if (current_prop.object_type != target_prop->object_type) {
validation_errors.push_back("Target object type for property '" + current_prop.name + "' does not match. " +
"Old type '" + current_prop.object_type +
"', new type '" + target_prop->object_type + "'.");
}
}
if (current_prop.is_primary != target_prop->is_primary) {
if (current_prop.is_primary) {
validation_errors.push_back("Property '" + current_prop.name + "' is no longer a primary key.");
}
else {
validation_errors.push_back("Property '" + current_prop.name + "' has been made a primary key.");
}
}
// create new property with aligned column
target_prop->table_column = current_prop.table_column;
}
// check for new missing properties
for (auto& target_prop : target_schema.properties) {
if (!table_schema.property_for_name(target_prop.name)) {
validation_errors.push_back("Property '" + target_prop.name + "' has been added to latest object model.");
}
}
return validation_errors;
}
void ObjectStore::update_column_mapping(Group *group, ObjectSchema &target_schema) {
ObjectSchema table_schema(group, target_schema.name);
for (auto& target_prop : target_schema.properties) {
auto table_prop = table_schema.property_for_name(target_prop.name);
REALM_ASSERT_DEBUG(table_prop);
target_prop.table_column = table_prop->table_column;
}
}
static inline bool property_has_changed(Property &p1, Property &p2) {
return p1.type != p2.type || p1.name != p2.name || p1.object_type != p2.object_type;
}
// set references to tables on targetSchema and create/update any missing or out-of-date tables
// if update existing is true, updates existing tables, otherwise validates existing tables
// NOTE: must be called from within write transaction
bool ObjectStore::create_tables(Group *group, ObjectStore::Schema &target_schema, bool update_existing) {
bool changed = false;
// first pass to create missing tables
vector<ObjectSchema *> to_update;
set<string> target_type_names;
for (auto& object_schema : target_schema) {
bool created = false;
ObjectStore::table_for_object_type_create_if_needed(group, object_schema.name, created);
// we will modify tables for any new objectSchema (table was created) or for all if update_existing is true
if (update_existing || created) {
to_update.push_back(&object_schema);
changed = true;
}
// keep track of names to figure out what tables need deletion
target_type_names.insert(object_schema.name);
}
// second pass adds/removes columns for out of date tables
for (auto& target_object_schema : to_update) {
TableRef table = table_for_object_type(group, target_object_schema->name);
ObjectSchema current_schema(group, target_object_schema->name);
vector<Property> &target_props = target_object_schema->properties;
// add missing columns
for (auto& target_prop : target_props) {
auto current_prop = current_schema.property_for_name(target_prop.name);
// add any new properties (new name or different type)
if (!current_prop || property_has_changed(*current_prop, target_prop)) {
switch (target_prop.type) {
// for objects and arrays, we have to specify target table
case PropertyTypeObject:
case PropertyTypeArray: {
TableRef link_table = ObjectStore::table_for_object_type(group, target_prop.object_type);
target_prop.table_column = table->add_column_link(DataType(target_prop.type), target_prop.name, *link_table);
break;
}
default:
target_prop.table_column = table->add_column(DataType(target_prop.type), target_prop.name);
break;
}
changed = true;
}
}
// remove extra columns
sort(begin(current_schema.properties), end(current_schema.properties), [](Property &i, Property &j) {
return j.table_column < i.table_column;
});
for (auto& current_prop : current_schema.properties) {
auto target_prop = target_object_schema->property_for_name(current_prop.name);
if (!target_prop || property_has_changed(current_prop, *target_prop)) {
table->remove_column(current_prop.table_column);
changed = true;
}
}
// update table metadata
if (target_object_schema->primary_key.length()) {
// if there is a primary key set, check if it is the same as the old key
if (current_schema.primary_key != target_object_schema->primary_key) {
set_primary_key_for_object(group, target_object_schema->name, target_object_schema->primary_key);
changed = true;
}
}
else if (current_schema.primary_key.length()) {
// there is no primary key, so if there was one nil out
set_primary_key_for_object(group, target_object_schema->name, "");
changed = true;
}
}
// remove primary key entries for deleted types
// FIXME - delete actual tables once we have proper testing
ObjectStore::Schema schema;
for (int i = (int)group->size() - 1; i >= 0 ; i--) {
string object_type = object_type_for_table_name(group->get_table_name(i));
if (object_type.length()) {
if (target_type_names.find(object_type) == target_type_names.end()) {
set_primary_key_for_object(group, object_type, "");
}
}
}
return changed;
}
bool ObjectStore::is_schema_at_version(Group *group, uint64_t version) {
uint64_t old_version = get_schema_version(group);
if (old_version > version && old_version != NotVersioned) {
throw ObjectStoreException(ObjectStoreException::Kind::RealmVersionGreaterThanSchemaVersion,
{{"old_version", to_string(old_version)}, {"new_version", to_string(version)}});
}
return old_version != version;
}
bool ObjectStore::update_realm_with_schema(Group *group,
uint64_t version,
Schema &schema,
MigrationFunction migration) {
// Recheck the schema version after beginning the write transaction as
// another process may have done the migration after we opened the read
// transaction
bool migrating = is_schema_at_version(group, version);
// create tables
bool changed = create_metadata_tables(group);
changed = create_tables(group, schema, migrating) || changed;
for (auto& target_schema : schema) {
// read-only realms may be missing tables entirely
TableRef table = table_for_object_type(group, target_schema.name);
if (table) {
auto errors = validate_schema(group, target_schema);
if (errors.size()) {
throw ObjectStoreValidationException(errors, target_schema.name);
}
}
}
changed = update_indexes(group, schema) || changed;
if (!migrating) {
return changed;
}
// apply the migration block if provided and there's any old data
if (get_schema_version(group) != ObjectStore::NotVersioned) {
migration(group, schema);
}
validate_primary_column_uniqueness(group, schema);
set_schema_version(group, version);
return true;
}
ObjectStore::Schema ObjectStore::schema_from_group(Group *group) {
ObjectStore::Schema schema;
for (size_t i = 0; i < group->size(); i++) {
string object_type = object_type_for_table_name(group->get_table_name(i));
if (object_type.length()) {
schema.emplace_back(group, move(object_type));
}
}
return schema;
}
bool ObjectStore::indexes_are_up_to_date(Group *group, Schema &schema) {
for (auto &object_schema : schema) {
TableRef table = table_for_object_type(group, object_schema.name);
if (!table) {
continue;
}
update_column_mapping(group, object_schema);
for (auto& property : object_schema.properties) {
if (property.requires_index() != table->has_search_index(property.table_column)) {
return false;
}
}
}
return true;
}
bool ObjectStore::update_indexes(Group *group, Schema &schema) {
bool changed = false;
for (auto& object_schema : schema) {
TableRef table = table_for_object_type(group, object_schema.name);
if (!table) {
continue;
}
for (auto& property : object_schema.properties) {
if (property.requires_index() == table->has_search_index(property.table_column)) {
continue;
}
changed = true;
if (property.requires_index()) {
try {
table->add_search_index(property.table_column);
}
catch (LogicError const&) {
throw ObjectStoreException(ObjectStoreException::Kind::RealmPropertyTypeNotIndexable, {
{"object_type", object_schema.name},
{"property_name", property.name},
{"property_type", string_for_property_type(property.type)}
});
}
}
else {
table->remove_search_index(property.table_column);
}
}
}
return changed;
}
void ObjectStore::validate_primary_column_uniqueness(Group *group, Schema &schema) {
for (auto& object_schema : schema) {
auto primary_prop = object_schema.primary_key_property();
if (!primary_prop) {
continue;
}
TableRef table = table_for_object_type(group, object_schema.name);
if (table->get_distinct_view(primary_prop->table_column).size() != table->size()) {
throw ObjectStoreException(ObjectStoreException::Kind::RealmDuplicatePrimaryKeyValue,
{{"object_type", object_schema.name}, {"property_name", primary_prop->name}});
}
}
}