mirror of
https://github.com/aljazceru/turso.git
synced 2025-12-25 20:14:21 +01:00
542 lines
20 KiB
Rust
542 lines
20 KiB
Rust
//! The VDBE bytecode code generator.
|
|
//!
|
|
//! This module is responsible for translating the SQL AST into a sequence of
|
|
//! instructions for the VDBE. The VDBE is a register-based virtual machine that
|
|
//! executes bytecode instructions. This code generator is responsible for taking
|
|
//! the SQL AST and generating the corresponding VDBE instructions. For example,
|
|
//! a SELECT statement will be translated into a sequence of instructions that
|
|
//! will read rows from the database and filter them according to a WHERE clause.
|
|
|
|
pub(crate) mod aggregation;
|
|
pub(crate) mod delete;
|
|
pub(crate) mod emitter;
|
|
pub(crate) mod expr;
|
|
pub(crate) mod group_by;
|
|
pub(crate) mod insert;
|
|
pub(crate) mod main_loop;
|
|
pub(crate) mod optimizer;
|
|
pub(crate) mod order_by;
|
|
pub(crate) mod plan;
|
|
pub(crate) mod planner;
|
|
pub(crate) mod pragma;
|
|
pub(crate) mod result_row;
|
|
pub(crate) mod select;
|
|
pub(crate) mod subquery;
|
|
|
|
use crate::schema::Schema;
|
|
use crate::storage::pager::Pager;
|
|
use crate::storage::sqlite3_ondisk::DatabaseHeader;
|
|
use crate::translate::delete::translate_delete;
|
|
use crate::util::PRIMARY_KEY_AUTOMATIC_INDEX_NAME_PREFIX;
|
|
use crate::vdbe::builder::CursorType;
|
|
use crate::vdbe::{builder::ProgramBuilder, insn::Insn, Program};
|
|
use crate::{bail_parse_error, Connection, LimboError, Result, SymbolTable};
|
|
use insert::translate_insert;
|
|
use select::translate_select;
|
|
use sqlite3_parser::ast::{self, fmt::ToTokens};
|
|
use std::cell::RefCell;
|
|
use std::fmt::Display;
|
|
use std::rc::{Rc, Weak};
|
|
|
|
/// Translate SQL statement into bytecode program.
|
|
pub fn translate(
|
|
schema: &Schema,
|
|
stmt: ast::Stmt,
|
|
database_header: Rc<RefCell<DatabaseHeader>>,
|
|
pager: Rc<Pager>,
|
|
connection: Weak<Connection>,
|
|
syms: &SymbolTable,
|
|
) -> Result<Program> {
|
|
let mut program = ProgramBuilder::new();
|
|
let mut change_cnt_on = false;
|
|
|
|
match stmt {
|
|
ast::Stmt::AlterTable(_, _) => bail_parse_error!("ALTER TABLE not supported yet"),
|
|
ast::Stmt::Analyze(_) => bail_parse_error!("ANALYZE not supported yet"),
|
|
ast::Stmt::Attach { .. } => bail_parse_error!("ATTACH not supported yet"),
|
|
ast::Stmt::Begin(_, _) => bail_parse_error!("BEGIN not supported yet"),
|
|
ast::Stmt::Commit(_) => bail_parse_error!("COMMIT not supported yet"),
|
|
ast::Stmt::CreateIndex { .. } => bail_parse_error!("CREATE INDEX not supported yet"),
|
|
ast::Stmt::CreateTable {
|
|
temporary,
|
|
if_not_exists,
|
|
tbl_name,
|
|
body,
|
|
} => {
|
|
if temporary {
|
|
bail_parse_error!("TEMPORARY table not supported yet");
|
|
}
|
|
|
|
translate_create_table(&mut program, tbl_name, body, if_not_exists, schema)?;
|
|
}
|
|
ast::Stmt::CreateTrigger { .. } => bail_parse_error!("CREATE TRIGGER not supported yet"),
|
|
ast::Stmt::CreateView { .. } => bail_parse_error!("CREATE VIEW not supported yet"),
|
|
ast::Stmt::CreateVirtualTable { .. } => {
|
|
bail_parse_error!("CREATE VIRTUAL TABLE not supported yet")
|
|
}
|
|
ast::Stmt::Delete {
|
|
tbl_name,
|
|
where_clause,
|
|
limit,
|
|
..
|
|
} => {
|
|
change_cnt_on = true;
|
|
translate_delete(&mut program, schema, &tbl_name, where_clause, limit, syms)?;
|
|
}
|
|
ast::Stmt::Detach(_) => bail_parse_error!("DETACH not supported yet"),
|
|
ast::Stmt::DropIndex { .. } => bail_parse_error!("DROP INDEX not supported yet"),
|
|
ast::Stmt::DropTable { .. } => bail_parse_error!("DROP TABLE not supported yet"),
|
|
ast::Stmt::DropTrigger { .. } => bail_parse_error!("DROP TRIGGER not supported yet"),
|
|
ast::Stmt::DropView { .. } => bail_parse_error!("DROP VIEW not supported yet"),
|
|
ast::Stmt::Pragma(name, body) => {
|
|
pragma::translate_pragma(
|
|
&mut program,
|
|
&schema,
|
|
&name,
|
|
body,
|
|
database_header.clone(),
|
|
pager,
|
|
)?;
|
|
}
|
|
ast::Stmt::Reindex { .. } => bail_parse_error!("REINDEX not supported yet"),
|
|
ast::Stmt::Release(_) => bail_parse_error!("RELEASE not supported yet"),
|
|
ast::Stmt::Rollback { .. } => bail_parse_error!("ROLLBACK not supported yet"),
|
|
ast::Stmt::Savepoint(_) => bail_parse_error!("SAVEPOINT not supported yet"),
|
|
ast::Stmt::Select(select) => {
|
|
translate_select(&mut program, schema, *select, syms)?;
|
|
}
|
|
ast::Stmt::Update { .. } => bail_parse_error!("UPDATE not supported yet"),
|
|
ast::Stmt::Vacuum(_, _) => bail_parse_error!("VACUUM not supported yet"),
|
|
ast::Stmt::Insert {
|
|
with,
|
|
or_conflict,
|
|
tbl_name,
|
|
columns,
|
|
body,
|
|
returning,
|
|
} => {
|
|
change_cnt_on = true;
|
|
translate_insert(
|
|
&mut program,
|
|
schema,
|
|
&with,
|
|
&or_conflict,
|
|
&tbl_name,
|
|
&columns,
|
|
&body,
|
|
&returning,
|
|
syms,
|
|
)?;
|
|
}
|
|
}
|
|
|
|
Ok(program.build(database_header, connection, change_cnt_on))
|
|
}
|
|
|
|
/* Example:
|
|
|
|
sqlite> EXPLAIN CREATE TABLE users (id INT, email TEXT);;
|
|
addr opcode p1 p2 p3 p4 p5 comment
|
|
---- ------------- ---- ---- ---- ------------- -- -------------
|
|
0 Init 0 30 0 0 Start at 30
|
|
1 ReadCookie 0 3 2 0
|
|
2 If 3 5 0 0
|
|
3 SetCookie 0 2 4 0
|
|
4 SetCookie 0 5 1 0
|
|
5 CreateBtree 0 2 1 0 r[2]=root iDb=0 flags=1
|
|
6 OpenWrite 0 1 0 5 0 root=1 iDb=0
|
|
7 NewRowid 0 1 0 0 r[1]=rowid
|
|
8 Blob 6 3 0 0 r[3]= (len=6)
|
|
9 Insert 0 3 1 8 intkey=r[1] data=r[3]
|
|
10 Close 0 0 0 0
|
|
11 Close 0 0 0 0
|
|
12 Null 0 4 5 0 r[4..5]=NULL
|
|
13 Noop 2 0 4 0
|
|
14 OpenWrite 1 1 0 5 0 root=1 iDb=0; sqlite_master
|
|
15 SeekRowid 1 17 1 0 intkey=r[1]
|
|
16 Rowid 1 5 0 0 r[5]= rowid of 1
|
|
17 IsNull 5 26 0 0 if r[5]==NULL goto 26
|
|
18 String8 0 6 0 table 0 r[6]='table'
|
|
19 String8 0 7 0 users 0 r[7]='users'
|
|
20 String8 0 8 0 users 0 r[8]='users'
|
|
21 Copy 2 9 0 0 r[9]=r[2]
|
|
22 String8 0 10 0 CREATE TABLE users (id INT, email TEXT) 0 r[10]='CREATE TABLE users (id INT, email TEXT)'
|
|
23 MakeRecord 6 5 4 BBBDB 0 r[4]=mkrec(r[6..10])
|
|
24 Delete 1 68 5 0
|
|
25 Insert 1 4 5 0 intkey=r[5] data=r[4]
|
|
26 SetCookie 0 1 1 0
|
|
27 ParseSchema 0 0 0 tbl_name='users' AND type!='trigger' 0
|
|
28 SqlExec 1 0 0 PRAGMA "main".integrity_check('users') 0
|
|
29 Halt 0 0 0 0
|
|
30 Transaction 0 1 0 0 1 usesStmtJournal=1
|
|
31 Goto 0 1 0 0
|
|
|
|
*/
|
|
#[derive(Debug)]
|
|
enum SchemaEntryType {
|
|
Table,
|
|
Index,
|
|
}
|
|
|
|
impl SchemaEntryType {
|
|
fn as_str(&self) -> &'static str {
|
|
match self {
|
|
SchemaEntryType::Table => "table",
|
|
SchemaEntryType::Index => "index",
|
|
}
|
|
}
|
|
}
|
|
|
|
fn emit_schema_entry(
|
|
program: &mut ProgramBuilder,
|
|
sqlite_schema_cursor_id: usize,
|
|
entry_type: SchemaEntryType,
|
|
name: &str,
|
|
tbl_name: &str,
|
|
root_page_reg: usize,
|
|
sql: Option<String>,
|
|
) {
|
|
let rowid_reg = program.alloc_register();
|
|
program.emit_insn(Insn::NewRowid {
|
|
cursor: sqlite_schema_cursor_id,
|
|
rowid_reg,
|
|
prev_largest_reg: 0,
|
|
});
|
|
|
|
let type_reg = program.emit_string8_new_reg(entry_type.as_str().to_string());
|
|
program.emit_string8_new_reg(name.to_string());
|
|
program.emit_string8_new_reg(tbl_name.to_string());
|
|
|
|
let rootpage_reg = program.alloc_register();
|
|
program.emit_insn(Insn::Copy {
|
|
src_reg: root_page_reg,
|
|
dst_reg: rootpage_reg,
|
|
amount: 1,
|
|
});
|
|
|
|
let sql_reg = program.alloc_register();
|
|
if let Some(sql) = sql {
|
|
program.emit_string8(sql, sql_reg);
|
|
} else {
|
|
program.emit_null(sql_reg);
|
|
}
|
|
|
|
let record_reg = program.alloc_register();
|
|
program.emit_insn(Insn::MakeRecord {
|
|
start_reg: type_reg,
|
|
count: 5,
|
|
dest_reg: record_reg,
|
|
});
|
|
|
|
program.emit_insn(Insn::InsertAsync {
|
|
cursor: sqlite_schema_cursor_id,
|
|
key_reg: rowid_reg,
|
|
record_reg,
|
|
flag: 0,
|
|
});
|
|
program.emit_insn(Insn::InsertAwait {
|
|
cursor_id: sqlite_schema_cursor_id,
|
|
});
|
|
}
|
|
|
|
struct PrimaryKeyColumnInfo<'a> {
|
|
name: &'a String,
|
|
is_descending: bool,
|
|
}
|
|
|
|
/// Check if an automatic PRIMARY KEY index is required for the table.
|
|
/// If so, create a register for the index root page and return it.
|
|
///
|
|
/// An automatic PRIMARY KEY index is not required if:
|
|
/// - The table has no PRIMARY KEY
|
|
/// - The table has a single-column PRIMARY KEY whose typename is _exactly_ "INTEGER" e.g. not "INT".
|
|
/// In this case, the PRIMARY KEY column becomes an alias for the rowid.
|
|
///
|
|
/// Otherwise, an automatic PRIMARY KEY index is required.
|
|
fn check_automatic_pk_index_required(
|
|
body: &ast::CreateTableBody,
|
|
program: &mut ProgramBuilder,
|
|
tbl_name: &str,
|
|
) -> Result<Option<usize>> {
|
|
match body {
|
|
ast::CreateTableBody::ColumnsAndConstraints {
|
|
columns,
|
|
constraints,
|
|
options,
|
|
} => {
|
|
let mut primary_key_definition = None;
|
|
|
|
// Check table constraints for PRIMARY KEY
|
|
if let Some(constraints) = constraints {
|
|
for constraint in constraints {
|
|
if let ast::TableConstraint::PrimaryKey {
|
|
columns: pk_cols, ..
|
|
} = &constraint.constraint
|
|
{
|
|
let primary_key_column_results: Vec<Result<PrimaryKeyColumnInfo>> = pk_cols
|
|
.iter()
|
|
.map(|col| match &col.expr {
|
|
ast::Expr::Id(name) => Ok(PrimaryKeyColumnInfo {
|
|
name: &name.0,
|
|
is_descending: matches!(col.order, Some(ast::SortOrder::Desc)),
|
|
}),
|
|
_ => Err(LimboError::ParseError(
|
|
"expressions prohibited in PRIMARY KEY and UNIQUE constraints"
|
|
.to_string(),
|
|
)),
|
|
})
|
|
.collect();
|
|
|
|
for result in primary_key_column_results {
|
|
if let Err(e) = result {
|
|
bail_parse_error!("{}", e);
|
|
}
|
|
let pk_info = result?;
|
|
|
|
let column_name = pk_info.name;
|
|
let column_def = columns.get(&ast::Name(column_name.clone()));
|
|
if column_def.is_none() {
|
|
bail_parse_error!("No such column: {}", column_name);
|
|
}
|
|
|
|
if matches!(
|
|
primary_key_definition,
|
|
Some(PrimaryKeyDefinitionType::Simple { .. })
|
|
) {
|
|
primary_key_definition = Some(PrimaryKeyDefinitionType::Composite);
|
|
continue;
|
|
}
|
|
if primary_key_definition.is_none() {
|
|
let column_def = column_def.unwrap();
|
|
let typename =
|
|
column_def.col_type.as_ref().map(|t| t.name.as_str());
|
|
let is_descending = pk_info.is_descending;
|
|
primary_key_definition = Some(PrimaryKeyDefinitionType::Simple {
|
|
typename,
|
|
is_descending,
|
|
});
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Check column constraints for PRIMARY KEY
|
|
for (_, col_def) in columns.iter() {
|
|
for constraint in &col_def.constraints {
|
|
if matches!(
|
|
constraint.constraint,
|
|
ast::ColumnConstraint::PrimaryKey { .. }
|
|
) {
|
|
if primary_key_definition.is_some() {
|
|
bail_parse_error!("table {} has more than one primary key", tbl_name);
|
|
}
|
|
let typename = col_def.col_type.as_ref().map(|t| t.name.as_str());
|
|
primary_key_definition = Some(PrimaryKeyDefinitionType::Simple {
|
|
typename,
|
|
is_descending: false,
|
|
});
|
|
}
|
|
}
|
|
}
|
|
|
|
// Check if table has rowid
|
|
if options.contains(ast::TableOptions::WITHOUT_ROWID) {
|
|
bail_parse_error!("WITHOUT ROWID tables are not supported yet");
|
|
}
|
|
|
|
// Check if we need an automatic index
|
|
let needs_auto_index = if let Some(primary_key_definition) = &primary_key_definition {
|
|
match primary_key_definition {
|
|
PrimaryKeyDefinitionType::Simple {
|
|
typename,
|
|
is_descending,
|
|
} => {
|
|
let is_integer =
|
|
typename.is_some() && typename.unwrap().to_uppercase() == "INTEGER";
|
|
!is_integer || *is_descending
|
|
}
|
|
PrimaryKeyDefinitionType::Composite => true,
|
|
}
|
|
} else {
|
|
false
|
|
};
|
|
|
|
if needs_auto_index {
|
|
let index_root_reg = program.alloc_register();
|
|
Ok(Some(index_root_reg))
|
|
} else {
|
|
Ok(None)
|
|
}
|
|
}
|
|
ast::CreateTableBody::AsSelect(_) => {
|
|
bail_parse_error!("CREATE TABLE AS SELECT not supported yet")
|
|
}
|
|
}
|
|
}
|
|
|
|
fn translate_create_table(
|
|
program: &mut ProgramBuilder,
|
|
tbl_name: ast::QualifiedName,
|
|
body: ast::CreateTableBody,
|
|
if_not_exists: bool,
|
|
schema: &Schema,
|
|
) -> Result<()> {
|
|
if schema.get_table(tbl_name.name.0.as_str()).is_some() {
|
|
if if_not_exists {
|
|
let init_label = program.emit_init();
|
|
let start_offset = program.offset();
|
|
program.emit_halt();
|
|
program.resolve_label(init_label, program.offset());
|
|
program.emit_transaction(true);
|
|
program.emit_constant_insns();
|
|
program.emit_goto(start_offset);
|
|
|
|
return Ok(());
|
|
}
|
|
bail_parse_error!("Table {} already exists", tbl_name);
|
|
}
|
|
|
|
let sql = create_table_body_to_str(&tbl_name, &body);
|
|
|
|
let parse_schema_label = program.allocate_label();
|
|
let init_label = program.emit_init();
|
|
let start_offset = program.offset();
|
|
// TODO: ReadCookie
|
|
// TODO: If
|
|
// TODO: SetCookie
|
|
// TODO: SetCookie
|
|
|
|
// Create the table B-tree
|
|
let table_root_reg = program.alloc_register();
|
|
program.emit_insn(Insn::CreateBtree {
|
|
db: 0,
|
|
root: table_root_reg,
|
|
flags: 1, // Table leaf page
|
|
});
|
|
|
|
// Create an automatic index B-tree if needed
|
|
//
|
|
// NOTE: we are deviating from SQLite bytecode here. For some reason, SQLite first creates a placeholder entry
|
|
// for the table in sqlite_schema, then writes the index to sqlite_schema, then UPDATEs the table placeholder entry
|
|
// in sqlite_schema with actual data.
|
|
//
|
|
// What we do instead is:
|
|
// 1. Create the table B-tree
|
|
// 2. Create the index B-tree
|
|
// 3. Add the table entry to sqlite_schema
|
|
// 4. Add the index entry to sqlite_schema
|
|
//
|
|
// I.e. we skip the weird song and dance with the placeholder entry. Unclear why sqlite does this.
|
|
// The sqlite code has this comment:
|
|
//
|
|
// "This just creates a place-holder record in the sqlite_schema table.
|
|
// The record created does not contain anything yet. It will be replaced
|
|
// by the real entry in code generated at sqlite3EndTable()."
|
|
//
|
|
// References:
|
|
// https://github.com/sqlite/sqlite/blob/95f6df5b8d55e67d1e34d2bff217305a2f21b1fb/src/build.c#L1355
|
|
// https://github.com/sqlite/sqlite/blob/95f6df5b8d55e67d1e34d2bff217305a2f21b1fb/src/build.c#L2856-L2871
|
|
// https://github.com/sqlite/sqlite/blob/95f6df5b8d55e67d1e34d2bff217305a2f21b1fb/src/build.c#L1334C5-L1336C65
|
|
|
|
let index_root_reg = check_automatic_pk_index_required(&body, program, &tbl_name.name.0)?;
|
|
if let Some(index_root_reg) = index_root_reg {
|
|
program.emit_insn(Insn::CreateBtree {
|
|
db: 0,
|
|
root: index_root_reg,
|
|
flags: 2, // Index leaf page
|
|
});
|
|
}
|
|
|
|
let table_id = "sqlite_schema".to_string();
|
|
let table = schema.get_table(&table_id).unwrap();
|
|
let sqlite_schema_cursor_id = program.alloc_cursor_id(
|
|
Some(table_id.to_owned()),
|
|
CursorType::BTreeTable(table.clone()),
|
|
);
|
|
program.emit_insn(Insn::OpenWriteAsync {
|
|
cursor_id: sqlite_schema_cursor_id,
|
|
root_page: 1,
|
|
});
|
|
program.emit_insn(Insn::OpenWriteAwait {});
|
|
|
|
// Add the table entry to sqlite_schema
|
|
emit_schema_entry(
|
|
program,
|
|
sqlite_schema_cursor_id,
|
|
SchemaEntryType::Table,
|
|
&tbl_name.name.0,
|
|
&tbl_name.name.0,
|
|
table_root_reg,
|
|
Some(sql),
|
|
);
|
|
|
|
// If we need an automatic index, add its entry to sqlite_schema
|
|
if let Some(index_root_reg) = index_root_reg {
|
|
let index_name = format!(
|
|
"{}{}_1",
|
|
PRIMARY_KEY_AUTOMATIC_INDEX_NAME_PREFIX, tbl_name.name.0
|
|
);
|
|
emit_schema_entry(
|
|
program,
|
|
sqlite_schema_cursor_id,
|
|
SchemaEntryType::Index,
|
|
&index_name,
|
|
&tbl_name.name.0,
|
|
index_root_reg,
|
|
None,
|
|
);
|
|
}
|
|
|
|
program.resolve_label(parse_schema_label, program.offset());
|
|
// TODO: SetCookie
|
|
//
|
|
// TODO: remove format, it sucks for performance but is convinient
|
|
let parse_schema_where_clause = format!("tbl_name = '{}' AND type != 'trigger'", tbl_name);
|
|
program.emit_insn(Insn::ParseSchema {
|
|
db: sqlite_schema_cursor_id,
|
|
where_clause: parse_schema_where_clause,
|
|
});
|
|
|
|
// TODO: SqlExec
|
|
program.emit_halt();
|
|
program.resolve_label(init_label, program.offset());
|
|
program.emit_transaction(true);
|
|
program.emit_constant_insns();
|
|
program.emit_goto(start_offset);
|
|
|
|
Ok(())
|
|
}
|
|
|
|
enum PrimaryKeyDefinitionType<'a> {
|
|
Simple {
|
|
typename: Option<&'a str>,
|
|
is_descending: bool,
|
|
},
|
|
Composite,
|
|
}
|
|
|
|
struct TableFormatter<'a> {
|
|
body: &'a ast::CreateTableBody,
|
|
}
|
|
impl Display for TableFormatter<'_> {
|
|
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
|
|
self.body.to_fmt(f)
|
|
}
|
|
}
|
|
|
|
fn create_table_body_to_str(tbl_name: &ast::QualifiedName, body: &ast::CreateTableBody) -> String {
|
|
let mut sql = String::new();
|
|
let formatter = TableFormatter { body };
|
|
sql.push_str(format!("CREATE TABLE {} {}", tbl_name.name.0, formatter).as_str());
|
|
match body {
|
|
ast::CreateTableBody::ColumnsAndConstraints {
|
|
columns: _,
|
|
constraints: _,
|
|
options: _,
|
|
} => {}
|
|
ast::CreateTableBody::AsSelect(_select) => todo!("as select not yet supported"),
|
|
}
|
|
sql
|
|
}
|