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/*
* Copyright (c) 2021, Jan de Visser <jan@de-visser.net>
* Copyright (c) 2021, Mahmoud Mandour <ma.mandourr@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Format.h>
#include <AK/RefPtr.h>
#include <AK/String.h>
#include <LibSQL/BTree.h>
#include <LibSQL/Database.h>
#include <LibSQL/Heap.h>
#include <LibSQL/Meta.h>
#include <LibSQL/Row.h>
#include <LibSQL/Tuple.h>
namespace SQL {
Database::Database(String name)
: m_heap(Heap::construct(move(name)))
, m_serializer(m_heap)
{
}
ResultOr<void> Database::open()
{
TRY(m_heap->open());
m_schemas = BTree::construct(m_serializer, SchemaDef::index_def()->to_tuple_descriptor(), m_heap->schemas_root());
m_schemas->on_new_root = [&]() {
m_heap->set_schemas_root(m_schemas->root());
};
m_tables = BTree::construct(m_serializer, TableDef::index_def()->to_tuple_descriptor(), m_heap->tables_root());
m_tables->on_new_root = [&]() {
m_heap->set_tables_root(m_tables->root());
};
m_table_columns = BTree::construct(m_serializer, ColumnDef::index_def()->to_tuple_descriptor(), m_heap->table_columns_root());
m_table_columns->on_new_root = [&]() {
m_heap->set_table_columns_root(m_table_columns->root());
};
m_open = true;
auto ensure_schema_exists = [&](auto schema_name) -> ResultOr<NonnullRefPtr<SchemaDef>> {
if (auto result = get_schema(schema_name); result.is_error()) {
if (result.error().error() != SQLErrorCode::SchemaDoesNotExist)
return result.release_error();
auto schema_def = SchemaDef::construct(schema_name);
TRY(add_schema(*schema_def));
return schema_def;
} else {
return result.release_value();
}
};
(void)TRY(ensure_schema_exists("default"sv));
auto master_schema = TRY(ensure_schema_exists("master"sv));
if (auto result = get_table("master"sv, "internal_describe_table"sv); result.is_error()) {
if (result.error().error() != SQLErrorCode::TableDoesNotExist)
return result.release_error();
auto internal_describe_table = TableDef::construct(master_schema, "internal_describe_table");
internal_describe_table->append_column("Name", SQLType::Text);
internal_describe_table->append_column("Type", SQLType::Text);
TRY(add_table(*internal_describe_table));
}
return {};
}
Database::~Database() = default;
ErrorOr<void> Database::commit()
{
VERIFY(is_open());
TRY(m_heap->flush());
return {};
}
ResultOr<void> Database::add_schema(SchemaDef const& schema)
{
VERIFY(is_open());
if (!m_schemas->insert(schema.key()))
return Result { SQLCommand::Unknown, SQLErrorCode::SchemaExists, schema.name() };
return {};
}
Key Database::get_schema_key(String const& schema_name)
{
auto key = SchemaDef::make_key();
key["schema_name"] = schema_name;
return key;
}
ResultOr<NonnullRefPtr<SchemaDef>> Database::get_schema(String const& schema)
{
VERIFY(is_open());
auto schema_name = schema;
if (schema.is_empty())
schema_name = "default"sv;
Key key = get_schema_key(schema_name);
if (auto it = m_schema_cache.find(key.hash()); it != m_schema_cache.end())
return it->value;
auto schema_iterator = m_schemas->find(key);
if (schema_iterator.is_end() || (*schema_iterator != key))
return Result { SQLCommand::Unknown, SQLErrorCode::SchemaDoesNotExist, schema_name };
auto schema_def = SchemaDef::construct(*schema_iterator);
m_schema_cache.set(key.hash(), schema_def);
return schema_def;
}
ResultOr<void> Database::add_table(TableDef& table)
{
VERIFY(is_open());
if (!m_tables->insert(table.key()))
return Result { SQLCommand::Unknown, SQLErrorCode::TableExists, table.name() };
for (auto& column : table.columns()) {
if (!m_table_columns->insert(column.key()))
VERIFY_NOT_REACHED();
}
return {};
}
Key Database::get_table_key(String const& schema_name, String const& table_name)
{
auto key = TableDef::make_key(get_schema_key(schema_name));
key["table_name"] = table_name;
return key;
}
ResultOr<NonnullRefPtr<TableDef>> Database::get_table(String const& schema, String const& name)
{
VERIFY(is_open());
auto schema_name = schema;
if (schema.is_empty())
schema_name = "default"sv;
Key key = get_table_key(schema_name, name);
if (auto it = m_table_cache.find(key.hash()); it != m_table_cache.end())
return it->value;
auto table_iterator = m_tables->find(key);
if (table_iterator.is_end() || (*table_iterator != key))
return Result { SQLCommand::Unknown, SQLErrorCode::TableDoesNotExist, String::formatted("{}.{}", schema_name, name) };
auto schema_def = TRY(get_schema(schema));
auto table_def = TableDef::construct(schema_def, name);
table_def->set_pointer((*table_iterator).pointer());
m_table_cache.set(key.hash(), table_def);
auto table_hash = table_def->hash();
auto column_key = ColumnDef::make_key(table_def);
for (auto it = m_table_columns->find(column_key); !it.is_end() && ((*it)["table_hash"].to_u32().value() == table_hash); ++it)
table_def->append_column(*it);
return table_def;
}
ErrorOr<Vector<Row>> Database::select_all(TableDef const& table)
{
VERIFY(m_table_cache.get(table.key().hash()).has_value());
Vector<Row> ret;
for (auto pointer = table.pointer(); pointer; pointer = ret.last().next_pointer()) {
ret.append(m_serializer.deserialize_block<Row>(pointer, table, pointer));
}
return ret;
}
ErrorOr<Vector<Row>> Database::match(TableDef const& table, Key const& key)
{
VERIFY(m_table_cache.get(table.key().hash()).has_value());
Vector<Row> ret;
// TODO Match key against indexes defined on table. If found,
// use the index instead of scanning the table.
for (auto pointer = table.pointer(); pointer;) {
auto row = m_serializer.deserialize_block<Row>(pointer, table, pointer);
if (row.match(key))
ret.append(row);
pointer = ret.last().next_pointer();
}
return ret;
}
ErrorOr<void> Database::insert(Row& row)
{
VERIFY(m_table_cache.get(row.table()->key().hash()).has_value());
// TODO Check constraints
row.set_pointer(m_heap->new_record_pointer());
row.set_next_pointer(row.table()->pointer());
TRY(update(row));
// TODO update indexes defined on table.
auto table_key = row.table()->key();
table_key.set_pointer(row.pointer());
VERIFY(m_tables->update_key_pointer(table_key));
row.table()->set_pointer(row.pointer());
return {};
}
ErrorOr<void> Database::update(Row& tuple)
{
VERIFY(m_table_cache.get(tuple.table()->key().hash()).has_value());
// TODO Check constraints
m_serializer.reset();
m_serializer.serialize_and_write<Tuple>(tuple);
// TODO update indexes defined on table.
return {};
}
}
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