mlisp/usql/usql.cpp

517 lines
18 KiB
C++

#include "usql.h"
#include "exception.h"
#include "ml_date.h"
#include <algorithm>
#include <fstream>
namespace usql {
std::unique_ptr<Table> USql::execute(const std::string &command) {
try {
std::unique_ptr<Node> node = m_parser.parse(command);
return execute(*node);
} catch (std::exception &e) {
return create_stmt_result_table(-1, e.what(), 0);
}
}
std::unique_ptr<Table> USql::execute(Node &node) {
// TODO optimize execution nodes here
switch (node.node_type) {
case NodeType::create_table:
return execute_create_table(static_cast<CreateTableNode &>(node));
case NodeType::create_table_as_select:
return execute_create_table_as_table(static_cast<CreateTableAsSelectNode &>(node));
case NodeType::insert_into:
return execute_insert_into_table(static_cast<InsertIntoTableNode &>(node));
case NodeType::select_from:
return execute_select(static_cast<SelectFromTableNode &>(node));
case NodeType::delete_from:
return execute_delete(static_cast<DeleteFromTableNode &>(node));
case NodeType::update_table:
return execute_update(static_cast<UpdateTableNode &>(node));
case NodeType::load_table:
return execute_load(static_cast<LoadIntoTableNode &>(node));
case NodeType::save_table:
return execute_save(static_cast<SaveTableNode &>(node));
case NodeType::drop_table:
return execute_drop(static_cast<DropTableNode &>(node));
default:
return create_stmt_result_table(-1, "unknown statement", 0);
}
}
std::unique_ptr<Table> USql::execute_create_table(CreateTableNode &node) {
check_table_not_exists(node.table_name);
Table table{node.table_name, node.cols_defs};
m_tables.push_back(table);
return create_stmt_result_table(0, "table created", 0);
}
std::unique_ptr<Table> USql::execute_create_table_as_table(CreateTableAsSelectNode &node) {
check_table_not_exists(node.table_name);
auto select = execute_select((SelectFromTableNode &) *node.select_table);
// create table
Table new_table{node.table_name, select->m_col_defs};
m_tables.push_back(new_table);
// copy rows
// must be here, if rows are put into new_table, they are lost during m_tables.push_table
Table *table = find_table(node.table_name);
for( Row& orig_row : select->m_rows) {
table->add_copy_of_row(orig_row);
}
select.release(); // is it correct? hoping not to release select table here and then when releasing CreateTableAsSelectNode
return create_stmt_result_table(0, "table created", table->m_rows.size());
}
std::unique_ptr<Table> USql::execute_load(LoadIntoTableNode &node) {
// find source table
Table *table_def = find_table(node.table_name);
// read data
std::ifstream ifs(node.filename);
std::string content((std::istreambuf_iterator<char>(ifs)),
(std::istreambuf_iterator<char>()));
// load rows
auto rows_cnt = table_def->load_csv_string(content);
return create_stmt_result_table(0, "load succeeded", rows_cnt);
}
std::unique_ptr<Table> USql::execute_save(SaveTableNode &node) {
// find source table
Table *table_def = find_table(node.table_name);
// make csv string
std::string csv_string = table_def->csv_string();
// save data
std::ofstream file(node.filename);
file << csv_string;
file.close();
return create_stmt_result_table(0, "save succeeded", 0);
}
std::unique_ptr<Table> USql::execute_drop(DropTableNode &node) {
auto name_cmp = [node](const Table& t) { return t.m_name == node.table_name; };
auto table_def = std::find_if(begin(m_tables), end(m_tables), name_cmp);
if (table_def != std::end(m_tables)) {
m_tables.erase(table_def);
return create_stmt_result_table(0, "drop succeeded", 0);
}
throw Exception("table not found (" + node.table_name + ")");
}
std::unique_ptr<Table> USql::execute_insert_into_table(InsertIntoTableNode &node) {
// TODO check column names.size = values.size
// find table
Table *table_def = find_table(node.table_name);
// prepare empty new_row
Row new_row = table_def->create_empty_row();
// copy values
for (size_t i = 0; i < node.cols_names.size(); i++) {
ColDefNode col_def = table_def->get_column_def(node.cols_names[i].name);
auto col_value = eval_value_node(table_def, new_row, node.cols_values[i].get());
new_row.setColumnValue(&col_def, col_value.get());
}
// append new_row
table_def->add_row(new_row);
return create_stmt_result_table(0, "insert succeeded", 1);
}
std::unique_ptr<Table> USql::execute_select(SelectFromTableNode &node) {
// find source table
Table *table = find_table(node.table_name);
// create result table
std::vector<ColDefNode> result_tbl_col_defs{};
std::vector<int> source_table_col_index{};
for (int i = 0; i < node.cols_names->size(); i++) {
auto [ src_tbl_col_index, rst_tbl_col_def ] = get_column_definition(table,
&node.cols_names->operator[](i), i);
source_table_col_index.push_back(src_tbl_col_index);
result_tbl_col_defs.push_back(rst_tbl_col_def);
}
auto result = std::make_unique<Table>("result", result_tbl_col_defs);
// execute access plan
for (auto row = begin(table->m_rows); row != end(table->m_rows); ++row) {
// eval where for row
if (eval_where(node.where.get(), table, *row)) {
// prepare empty row
Row new_row = result->create_empty_row();
// copy column values
for (auto idx = 0; idx < result->columns_count(); idx++) {
auto row_col_index = source_table_col_index[idx];
if (row_col_index == -1) { // TODO introduce constant here
auto evaluated_value = eval_value_node(table, *row, node.cols_names->operator[](
idx).value.get());
ValueNode *col_value = evaluated_value.get();
new_row.setColumnValue(&result_tbl_col_defs[idx], col_value);
} else {
ColValue *col_value = row->ith_column(row_col_index);
new_row.setColumnValue(&result_tbl_col_defs[idx], col_value);
}
}
// add row to result
result->m_rows.push_back(new_row);
}
}
return std::move(result);
}
std::tuple<int, ColDefNode> USql::get_column_definition(Table *table, SelectColNode *select_col_node, int col_order ) {
std::string new_col_name = select_col_node->name;
if (select_col_node->value->node_type == NodeType::column_name) {
ColDefNode src_cdef = table->get_column_def(new_col_name);
ColDefNode cdef = ColDefNode{new_col_name, src_cdef.type, col_order, src_cdef.length, src_cdef.null};
return std::make_tuple(src_cdef.order, cdef);
} else if (select_col_node->value->node_type == NodeType::function) {
auto node = static_cast<FunctionNode *>(select_col_node->value.get());
if (node->function == "to_string") {
ColDefNode cdef = ColDefNode{new_col_name, ColumnType::varchar_type, col_order, 64, true};
return std::make_tuple(-1, cdef);
} else if (node->function == "to_date") {
ColDefNode cdef = ColDefNode{new_col_name, ColumnType::integer_type, col_order, 1, true};
return std::make_tuple(-1, cdef);
}
throw Exception("Unsupported function");
}
throw Exception("Unsupported node type");
}
std::unique_ptr<Table> USql::execute_delete(DeleteFromTableNode &node) {
// find source table
Table *table = find_table(node.table_name);
// execute access plan
int affected_rows = 0;
auto it = table->m_rows.begin();
for (; it != table->m_rows.end();) {
if (eval_where(node.where.get(), table, *it)) {
it = table->m_rows.erase(it);
affected_rows++;
} else {
++it;
}
}
return create_stmt_result_table(0, "delete succeeded", affected_rows);
}
std::unique_ptr<Table> USql::execute_update(UpdateTableNode &node) {
// find source table
Table *table = find_table(node.table_name);
// execute access plan
int affected_rows = 0;
for (auto row = begin(table->m_rows); row != end(table->m_rows); ++row) {
// eval where for row
if (eval_where(node.where.get(), table, *row)) {
int i = 0;
for (const auto& col : node.cols_names) {
ColDefNode col_def = table->get_column_def(col.name); // TODO cache it like in select
std::unique_ptr<ValueNode> new_val = eval_arithmetic_operator(col_def.type,
static_cast<ArithmeticalOperatorNode &>(*node.values[i]),
table, *row);
table->validate_column(&col_def, new_val.get());
row->setColumnValue(&col_def, new_val.get());
i++;
}
affected_rows++;
// TODO tady je problem, ze kdyz to zfajluje na jednom radku ostatni by se nemely provest
}
}
return create_stmt_result_table(0, "update succeeded", affected_rows);
}
bool USql::eval_where(Node *where, Table *table, Row &row) const {
switch (where->node_type) { // no where clause
case NodeType::true_node:
return true;
case NodeType::relational_operator: // just one condition
return eval_relational_operator(*((RelationalOperatorNode *) where), table, row);
case NodeType::logical_operator:
return eval_logical_operator(*((LogicalOperatorNode *) where), table, row);
default:
throw Exception("Wrong node type");
}
return false;
}
bool USql::eval_relational_operator(const RelationalOperatorNode &filter, Table *table, Row &row) const {
std::unique_ptr<ValueNode> left_value = eval_value_node(table, row, filter.left.get());
std::unique_ptr<ValueNode> right_value = eval_value_node(table, row, filter.right.get());
double comparator;
if (left_value->node_type == NodeType::int_value && right_value->node_type == NodeType::int_value) {
comparator = left_value->getIntValue() - right_value->getIntValue();
} else if ((left_value->node_type == NodeType::int_value && right_value->node_type == NodeType::float_value) ||
(left_value->node_type == NodeType::float_value && right_value->node_type == NodeType::int_value) ||
(left_value->node_type == NodeType::float_value && right_value->node_type == NodeType::float_value)) {
comparator = left_value->getDoubleValue() - right_value->getDoubleValue();
} else if (left_value->node_type == NodeType::string_value || right_value->node_type == NodeType::string_value) {
comparator = left_value->getStringValue().compare(right_value->getStringValue());
} else {
// TODO throw exception
}
switch (filter.op) {
case RelationalOperatorType::equal:
return comparator == 0.0;
case RelationalOperatorType::not_equal:
return comparator != 0.0;
case RelationalOperatorType::greater:
return comparator > 0.0;
case RelationalOperatorType::greater_equal:
return comparator >= 0.0;
case RelationalOperatorType::lesser:
return comparator < 0.0;
case RelationalOperatorType::lesser_equal:
return comparator <= 0.0;
}
throw Exception("invalid relational operator");
}
std::unique_ptr<ValueNode> USql::eval_value_node(Table *table, Row &row, Node *node) {
if (node->node_type == NodeType::database_value || node->node_type == NodeType::column_name) { // TODO sjednotit
return eval_database_value_node(table, row, node);
} else if (node->node_type == NodeType::int_value || node->node_type == NodeType::float_value || node->node_type == NodeType::string_value) {
return eval_literal_value_node(table, row, node);
} else if (node->node_type == NodeType::function) {
return eval_function_value_node(table, row, node);
} else if (node->node_type == NodeType::null_value) {
return std::make_unique<NullValueNode>();
}
throw Exception("unsupported node type");
}
std::unique_ptr<ValueNode> USql::eval_database_value_node(Table *table, Row &row, Node *node) {
auto *dvl = static_cast<DatabaseValueNode *>(node);
ColDefNode col_def = table->get_column_def( dvl->col_name); // TODO optimize it to just get this def once
auto db_value = row.ith_column(col_def.order);
if (col_def.type == ColumnType::integer_type) {
return std::make_unique<IntValueNode>(db_value->getIntValue());
}
if (col_def.type == ColumnType::float_type) {
return std::make_unique<DoubleValueNode>(db_value->getDoubleValue());
}
if (col_def.type == ColumnType::varchar_type) {
return std::make_unique<StringValueNode>(db_value->getStringValue());
}
throw Exception("unknown database value type");
}
std::unique_ptr<ValueNode> USql::eval_literal_value_node(Table *table, Row &row, Node *node) {
if (node->node_type == NodeType::int_value) {
auto *ivl = static_cast<IntValueNode *>(node);
return std::make_unique<IntValueNode>(ivl->value);
} else if (node->node_type == NodeType::float_value) {
auto *ivl = static_cast<DoubleValueNode *>(node);
return std::make_unique<DoubleValueNode>(ivl->value);
} else if (node->node_type == NodeType::string_value) {
auto *ivl = static_cast<StringValueNode *>(node);
return std::make_unique<StringValueNode>(ivl->value);
}
throw Exception("invalid type");
}
std::unique_ptr<ValueNode> USql::eval_function_value_node(Table *table, Row &row, Node *node) {
auto *fnc = static_cast<FunctionNode *>(node);
std::vector<std::unique_ptr<ValueNode>> evaluatedPars;
for(auto & param : fnc->params) {
evaluatedPars.push_back(eval_value_node(table, row, param.get()));
}
// TODO use some enum
if (fnc->function == "lower") {
std::string str = evaluatedPars[0]->getStringValue();
std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c) -> unsigned char { return std::tolower(c); });
return std::make_unique<StringValueNode>(str);
}
if (fnc->function == "upper") {
std::string str = evaluatedPars[0]->getStringValue();
std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c) -> unsigned char { return std::toupper(c); });
return std::make_unique<StringValueNode>(str);
}
if (fnc->function == "to_date") {
std::string date = evaluatedPars[0]->getStringValue();
std::string format = evaluatedPars[1]->getStringValue();
long epoch_time = string_to_date(date, format);
return std::make_unique<IntValueNode>(epoch_time);
}
if (fnc->function == "to_string") {
long date = evaluatedPars[0]->getIntValue();
std::string format = evaluatedPars[1]->getStringValue();
std::string formated_date = date_to_string(date, format);
return std::make_unique<StringValueNode>(formated_date);
}
throw Exception("invalid function");
}
bool USql::eval_logical_operator(LogicalOperatorNode &node, Table *pTable, Row &row) const {
bool left = eval_relational_operator(static_cast<const RelationalOperatorNode &>(*node.left), pTable, row);
if ((node.op == LogicalOperatorType::and_operator && !left) || (node.op == LogicalOperatorType::or_operator && left))
return left;
bool right = eval_relational_operator(static_cast<const RelationalOperatorNode &>(*node.right), pTable, row);
return right;
}
std::unique_ptr<ValueNode> USql::eval_arithmetic_operator(ColumnType outType, ArithmeticalOperatorNode &node, Table *table, Row &row) const {
if (node.op == ArithmeticalOperatorType::copy_value) {
return eval_value_node(table, row, node.left.get());
}
std::unique_ptr<ValueNode> left = eval_value_node(table, row, node.left.get());
std::unique_ptr<ValueNode> right = eval_value_node(table, row, node.right.get());
if (outType == ColumnType::float_type) {
double l = ((ValueNode *) left.get())->getDoubleValue();
double r = ((ValueNode *) right.get())->getDoubleValue();
switch (node.op) {
case ArithmeticalOperatorType::plus_operator:
return std::make_unique<DoubleValueNode>(l + r);
case ArithmeticalOperatorType::minus_operator:
return std::make_unique<DoubleValueNode>(l - r);
case ArithmeticalOperatorType::multiply_operator:
return std::make_unique<DoubleValueNode>(l * r);
case ArithmeticalOperatorType::divide_operator:
return std::make_unique<DoubleValueNode>(l / r);
default:
throw Exception("implement me!!");
}
} else if (outType == ColumnType::integer_type) {
long l = ((ValueNode *) left.get())->getIntValue();
long r = ((ValueNode *) right.get())->getIntValue();
switch (node.op) {
case ArithmeticalOperatorType::plus_operator:
return std::make_unique<IntValueNode>(l + r);
case ArithmeticalOperatorType::minus_operator:
return std::make_unique<IntValueNode>(l - r);
case ArithmeticalOperatorType::multiply_operator:
return std::make_unique<IntValueNode>(l * r);
case ArithmeticalOperatorType::divide_operator:
return std::make_unique<IntValueNode>(l / r);
default:
throw Exception("implement me!!");
}
} else if (outType == ColumnType::varchar_type) {
std::string l = ((ValueNode *) left.get())->getStringValue();
std::string r = ((ValueNode *) right.get())->getStringValue();
switch (node.op) {
case ArithmeticalOperatorType::plus_operator:
return std::make_unique<StringValueNode>(l + r);
default:
throw Exception("implement me!!");
}
}
throw Exception("implement me!!");
}
std::unique_ptr<Table> USql::create_stmt_result_table(long code, const std::string &text, long affected_rows) {
std::vector<ColDefNode> result_tbl_col_defs{};
result_tbl_col_defs.push_back(ColDefNode("code", ColumnType::integer_type, 0, 1, false));
result_tbl_col_defs.push_back(ColDefNode("desc", ColumnType::varchar_type, 1, 255, false));
result_tbl_col_defs.push_back(ColDefNode("affected_rows", ColumnType::integer_type, 0, 1, true));
auto table_def = std::make_unique<Table>("result", result_tbl_col_defs);
Row new_row = table_def->create_empty_row();
new_row.setColumnValue(0, code);
new_row.setColumnValue(1, text);
new_row.setColumnValue(2, affected_rows);
table_def->add_row(new_row);
return std::move(table_def);
}
Table *USql::find_table(const std::string &name) {
auto name_cmp = [name](const Table& t) { return t.m_name == name; };
auto table_def = std::find_if(begin(m_tables), end(m_tables), name_cmp);
if (table_def != std::end(m_tables)) {
return table_def.operator->();
} else {
throw Exception("table not found (" + name + ")");
}
}
void USql::check_table_not_exists(const std::string &name) {
auto name_cmp = [name](const Table& t) { return t.m_name == name; };
auto table_def = std::find_if(begin(m_tables), end(m_tables), name_cmp);
if (table_def != std::end(m_tables)) {
throw Exception("table already exists");
}
}
} // namespace