Files
turso/core/translate/emitter.rs
2025-10-27 16:01:39 +02:00

2195 lines
76 KiB
Rust

// This module contains code for emitting bytecode instructions for SQL query execution.
// It handles translating high-level SQL operations into low-level bytecode that can be executed by the virtual machine.
use std::collections::HashSet;
use std::num::NonZeroUsize;
use std::sync::Arc;
use tracing::{instrument, Level};
use turso_parser::ast::{self, Expr, Literal};
use super::aggregation::emit_ungrouped_aggregation;
use super::expr::translate_expr;
use super::group_by::{
group_by_agg_phase, group_by_emit_row_phase, init_group_by, GroupByMetadata, GroupByRowSource,
};
use super::main_loop::{
close_loop, emit_loop, init_distinct, init_loop, open_loop, LeftJoinMetadata, LoopLabels,
};
use super::order_by::{emit_order_by, init_order_by, SortMetadata};
use super::plan::{
Distinctness, JoinOrderMember, Operation, Scan, SelectPlan, TableReferences, UpdatePlan,
};
use super::select::emit_simple_count;
use super::subquery::emit_from_clause_subqueries;
use crate::error::SQLITE_CONSTRAINT_PRIMARYKEY;
use crate::function::Func;
use crate::schema::{BTreeTable, Column, Schema, Table, ROWID_SENTINEL};
use crate::translate::compound_select::emit_program_for_compound_select;
use crate::translate::expr::{
emit_returning_results, translate_expr_no_constant_opt, walk_expr_mut, NoConstantOptReason,
ReturningValueRegisters, WalkControl,
};
use crate::translate::fkeys::{
build_index_affinity_string, emit_fk_child_update_counters,
emit_fk_delete_parent_existence_checks, emit_guarded_fk_decrement,
emit_parent_key_change_checks, open_read_index, open_read_table, stabilize_new_row_for_fk,
};
use crate::translate::plan::{DeletePlan, JoinedTable, Plan, QueryDestination, Search};
use crate::translate::planner::ROWID_STRS;
use crate::translate::values::emit_values;
use crate::translate::window::{emit_window_results, init_window, WindowMetadata};
use crate::util::{exprs_are_equivalent, normalize_ident};
use crate::vdbe::builder::{CursorKey, CursorType, ProgramBuilder};
use crate::vdbe::insn::{CmpInsFlags, IdxInsertFlags, InsertFlags, RegisterOrLiteral};
use crate::vdbe::{insn::Insn, BranchOffset};
use crate::Connection;
use crate::{bail_parse_error, Result, SymbolTable};
pub struct Resolver<'a> {
pub schema: &'a Schema,
pub symbol_table: &'a SymbolTable,
pub expr_to_reg_cache_enabled: bool,
pub expr_to_reg_cache: Vec<(&'a ast::Expr, usize)>,
}
impl<'a> Resolver<'a> {
pub fn new(schema: &'a Schema, symbol_table: &'a SymbolTable) -> Self {
Self {
schema,
symbol_table,
expr_to_reg_cache_enabled: false,
expr_to_reg_cache: Vec::new(),
}
}
pub fn resolve_function(&self, func_name: &str, arg_count: usize) -> Option<Func> {
match Func::resolve_function(func_name, arg_count).ok() {
Some(func) => Some(func),
None => self
.symbol_table
.resolve_function(func_name, arg_count)
.map(|arg| Func::External(arg.clone())),
}
}
pub(crate) fn enable_expr_to_reg_cache(&mut self) {
self.expr_to_reg_cache_enabled = true;
}
pub fn resolve_cached_expr_reg(&self, expr: &ast::Expr) -> Option<usize> {
if self.expr_to_reg_cache_enabled {
self.expr_to_reg_cache
.iter()
.find(|(e, _)| exprs_are_equivalent(expr, e))
.map(|(_, reg)| *reg)
} else {
None
}
}
}
#[derive(Debug, Clone, Copy)]
pub struct LimitCtx {
/// Register holding the LIMIT value (e.g. LIMIT 5)
pub reg_limit: usize,
/// Whether to initialize the LIMIT counter to the LIMIT value;
/// There are cases like compound SELECTs where all the sub-selects
/// utilize the same limit register, but it is initialized only once.
pub initialize_counter: bool,
}
impl LimitCtx {
pub fn new(program: &mut ProgramBuilder) -> Self {
Self {
reg_limit: program.alloc_register(),
initialize_counter: true,
}
}
pub fn new_shared(reg_limit: usize) -> Self {
Self {
reg_limit,
initialize_counter: false,
}
}
}
/// The TranslateCtx struct holds various information and labels used during bytecode generation.
/// It is used for maintaining state and control flow during the bytecode
/// generation process.
pub struct TranslateCtx<'a> {
// A typical query plan is a nested loop. Each loop has its own LoopLabels (see the definition of LoopLabels for more details)
pub labels_main_loop: Vec<LoopLabels>,
// label for the instruction that jumps to the next phase of the query after the main loop
// we don't know ahead of time what that is (GROUP BY, ORDER BY, etc.)
pub label_main_loop_end: Option<BranchOffset>,
// First register of the aggregation results
pub reg_agg_start: Option<usize>,
// In non-group-by statements with aggregations (e.g. SELECT foo, bar, sum(baz) FROM t),
// we want to emit the non-aggregate columns (foo and bar) only once.
// This register is a flag that tracks whether we have already done that.
pub reg_nonagg_emit_once_flag: Option<usize>,
// First register of the result columns of the query
pub reg_result_cols_start: Option<usize>,
pub limit_ctx: Option<LimitCtx>,
// The register holding the offset value, if any.
pub reg_offset: Option<usize>,
// The register holding the limit+offset value, if any.
pub reg_limit_offset_sum: Option<usize>,
// metadata for the group by operator
pub meta_group_by: Option<GroupByMetadata>,
// metadata for the order by operator
pub meta_sort: Option<SortMetadata>,
/// mapping between table loop index and associated metadata (for left joins only)
/// this metadata exists for the right table in a given left join
pub meta_left_joins: Vec<Option<LeftJoinMetadata>>,
pub resolver: Resolver<'a>,
/// A list of expressions that are not aggregates, along with a flag indicating
/// whether the expression should be included in the output for each group.
///
/// Each entry is a tuple:
/// - `&'ast Expr`: the expression itself
/// - `bool`: `true` if the expression should be included in the output for each group, `false` otherwise.
///
/// The order of expressions is **significant**:
/// - First: all `GROUP BY` expressions, in the order they appear in the `GROUP BY` clause.
/// - Then: remaining non-aggregate expressions that are not part of `GROUP BY`.
pub non_aggregate_expressions: Vec<(&'a Expr, bool)>,
/// Cursor id for cdc table (if capture_data_changes PRAGMA is set and query can modify the data)
pub cdc_cursor_id: Option<usize>,
pub meta_window: Option<WindowMetadata<'a>>,
}
impl<'a> TranslateCtx<'a> {
pub fn new(
program: &mut ProgramBuilder,
schema: &'a Schema,
syms: &'a SymbolTable,
table_count: usize,
) -> Self {
TranslateCtx {
labels_main_loop: (0..table_count).map(|_| LoopLabels::new(program)).collect(),
label_main_loop_end: None,
reg_agg_start: None,
reg_nonagg_emit_once_flag: None,
limit_ctx: None,
reg_offset: None,
reg_limit_offset_sum: None,
reg_result_cols_start: None,
meta_group_by: None,
meta_left_joins: (0..table_count).map(|_| None).collect(),
meta_sort: None,
resolver: Resolver::new(schema, syms),
non_aggregate_expressions: Vec::new(),
cdc_cursor_id: None,
meta_window: None,
}
}
}
#[derive(Debug, Clone)]
/// Update row source for UPDATE statements
/// `Normal` is the default mode, it will iterate either the table itself or an index on the table.
/// `PrebuiltEphemeralTable` is used when an ephemeral table containing the target rowids to update has
/// been built and it is being used for iteration.
pub enum UpdateRowSource {
/// Iterate over the table itself or an index on the table
Normal,
/// Iterate over an ephemeral table containing the target rowids to update
PrebuiltEphemeralTable {
/// The cursor id of the ephemeral table that is being used to iterate the target rowids to update.
ephemeral_table_cursor_id: usize,
/// The table that is being updated.
target_table: Arc<JoinedTable>,
},
}
/// Used to distinguish database operations
#[allow(clippy::upper_case_acronyms, dead_code)]
#[derive(Debug, Clone)]
pub enum OperationMode {
SELECT,
INSERT,
UPDATE(UpdateRowSource),
DELETE,
}
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
/// Sqlite always considers Read transactions implicit
pub enum TransactionMode {
None,
Read,
Write,
Concurrent,
}
/// Main entry point for emitting bytecode for a SQL query
/// Takes a query plan and generates the corresponding bytecode program
#[instrument(skip_all, level = Level::DEBUG)]
pub fn emit_program(
connection: &Arc<Connection>,
resolver: &Resolver,
program: &mut ProgramBuilder,
plan: Plan,
after: impl FnOnce(&mut ProgramBuilder),
) -> Result<()> {
match plan {
Plan::Select(plan) => emit_program_for_select(program, resolver, plan),
Plan::Delete(plan) => emit_program_for_delete(connection, resolver, program, plan),
Plan::Update(plan) => emit_program_for_update(connection, resolver, program, plan, after),
Plan::CompoundSelect { .. } => emit_program_for_compound_select(program, resolver, plan),
}
}
#[instrument(skip_all, level = Level::DEBUG)]
pub fn emit_program_for_select(
program: &mut ProgramBuilder,
resolver: &Resolver,
mut plan: SelectPlan,
) -> Result<()> {
let mut t_ctx = TranslateCtx::new(
program,
resolver.schema,
resolver.symbol_table,
plan.table_references.joined_tables().len(),
);
// Emit main parts of query
emit_query(program, &mut plan, &mut t_ctx)?;
program.result_columns = plan.result_columns;
program.table_references.extend(plan.table_references);
Ok(())
}
#[instrument(skip_all, level = Level::DEBUG)]
pub fn emit_query<'a>(
program: &mut ProgramBuilder,
plan: &'a mut SelectPlan,
t_ctx: &mut TranslateCtx<'a>,
) -> Result<usize> {
let after_main_loop_label = program.allocate_label();
t_ctx.label_main_loop_end = Some(after_main_loop_label);
init_limit(program, t_ctx, &plan.limit, &plan.offset)?;
if !plan.values.is_empty() {
let reg_result_cols_start = emit_values(program, plan, t_ctx)?;
program.preassign_label_to_next_insn(after_main_loop_label);
return Ok(reg_result_cols_start);
}
// Emit FROM clause subqueries first so the results can be read in the main query loop.
emit_from_clause_subqueries(program, t_ctx, &mut plan.table_references)?;
// No rows will be read from source table loops if there is a constant false condition eg. WHERE 0
// however an aggregation might still happen,
// e.g. SELECT COUNT(*) WHERE 0 returns a row with 0, not an empty result set
if plan.contains_constant_false_condition {
program.emit_insn(Insn::Goto {
target_pc: after_main_loop_label,
});
}
// For non-grouped aggregation queries that also have non-aggregate columns,
// we need to ensure non-aggregate columns are only emitted once.
// This flag helps track whether we've already emitted these columns.
if !plan.aggregates.is_empty()
&& plan.group_by.is_none()
&& plan.result_columns.iter().any(|c| !c.contains_aggregates)
{
let flag = program.alloc_register();
program.emit_int(0, flag); // Initialize flag to 0 (not yet emitted)
t_ctx.reg_nonagg_emit_once_flag = Some(flag);
}
// Allocate registers for result columns
if t_ctx.reg_result_cols_start.is_none() {
t_ctx.reg_result_cols_start = Some(program.alloc_registers(plan.result_columns.len()));
program.reg_result_cols_start = t_ctx.reg_result_cols_start
}
// Initialize cursors and other resources needed for query execution
if !plan.order_by.is_empty() {
init_order_by(
program,
t_ctx,
&plan.result_columns,
&plan.order_by,
&plan.table_references,
plan.group_by.is_some(),
plan.distinctness != Distinctness::NonDistinct,
&plan.aggregates,
)?;
}
if let Some(ref group_by) = plan.group_by {
init_group_by(
program,
t_ctx,
group_by,
plan,
&plan.result_columns,
&plan.order_by,
)?;
} else if !plan.aggregates.is_empty() {
// Aggregate registers need to be NULLed at the start because the same registers might be reused on another invocation of a subquery,
// and if they are not NULLed, the 2nd invocation of the same subquery will have values left over from the first invocation.
t_ctx.reg_agg_start = Some(program.alloc_registers_and_init_w_null(plan.aggregates.len()));
} else if let Some(window) = &plan.window {
init_window(
program,
t_ctx,
window,
plan,
&plan.result_columns,
&plan.order_by,
)?;
}
let distinct_ctx = if let Distinctness::Distinct { .. } = &plan.distinctness {
Some(init_distinct(program, plan)?)
} else {
None
};
if let Distinctness::Distinct { ctx } = &mut plan.distinctness {
*ctx = distinct_ctx
}
init_loop(
program,
t_ctx,
&plan.table_references,
&mut plan.aggregates,
plan.group_by.as_ref(),
OperationMode::SELECT,
&plan.where_clause,
&plan.join_order,
&mut plan.non_from_clause_subqueries,
)?;
if plan.is_simple_count() {
emit_simple_count(program, t_ctx, plan)?;
return Ok(t_ctx.reg_result_cols_start.unwrap());
}
// Set up main query execution loop
open_loop(
program,
t_ctx,
&plan.table_references,
&plan.join_order,
&plan.where_clause,
None,
OperationMode::SELECT,
&mut plan.non_from_clause_subqueries,
)?;
// Process result columns and expressions in the inner loop
emit_loop(program, t_ctx, plan)?;
// Clean up and close the main execution loop
close_loop(
program,
t_ctx,
&plan.table_references,
&plan.join_order,
OperationMode::SELECT,
)?;
program.preassign_label_to_next_insn(after_main_loop_label);
let mut order_by_necessary =
!plan.order_by.is_empty() && !plan.contains_constant_false_condition;
let order_by = &plan.order_by;
// Handle GROUP BY and aggregation processing
if plan.group_by.is_some() {
let row_source = &t_ctx
.meta_group_by
.as_ref()
.expect("group by metadata not found")
.row_source;
if matches!(row_source, GroupByRowSource::Sorter { .. }) {
group_by_agg_phase(program, t_ctx, plan)?;
}
group_by_emit_row_phase(program, t_ctx, plan)?;
} else if !plan.aggregates.is_empty() {
// Handle aggregation without GROUP BY
emit_ungrouped_aggregation(program, t_ctx, plan)?;
// Single row result for aggregates without GROUP BY, so ORDER BY not needed
order_by_necessary = false;
} else if plan.window.is_some() {
emit_window_results(program, t_ctx, plan)?;
}
// Process ORDER BY results if needed
if !order_by.is_empty() && order_by_necessary {
emit_order_by(program, t_ctx, plan)?;
}
Ok(t_ctx.reg_result_cols_start.unwrap())
}
#[instrument(skip_all, level = Level::DEBUG)]
fn emit_program_for_delete(
connection: &Arc<Connection>,
resolver: &Resolver,
program: &mut ProgramBuilder,
mut plan: DeletePlan,
) -> Result<()> {
let mut t_ctx = TranslateCtx::new(
program,
resolver.schema,
resolver.symbol_table,
plan.table_references.joined_tables().len(),
);
let after_main_loop_label = program.allocate_label();
t_ctx.label_main_loop_end = Some(after_main_loop_label);
init_limit(program, &mut t_ctx, &plan.limit, &None)?;
// No rows will be read from source table loops if there is a constant false condition eg. WHERE 0
if plan.contains_constant_false_condition {
program.emit_insn(Insn::Goto {
target_pc: after_main_loop_label,
});
}
// Initialize cursors and other resources needed for query execution
init_loop(
program,
&mut t_ctx,
&plan.table_references,
&mut [],
None,
OperationMode::DELETE,
&plan.where_clause,
&[JoinOrderMember::default()],
&mut [],
)?;
// Set up main query execution loop
open_loop(
program,
&mut t_ctx,
&plan.table_references,
&[JoinOrderMember::default()],
&plan.where_clause,
None,
OperationMode::DELETE,
&mut [],
)?;
emit_delete_insns(
connection,
program,
&mut t_ctx,
&mut plan.table_references,
&plan.result_columns,
)?;
// Clean up and close the main execution loop
close_loop(
program,
&mut t_ctx,
&plan.table_references,
&[JoinOrderMember::default()],
OperationMode::DELETE,
)?;
program.preassign_label_to_next_insn(after_main_loop_label);
// Finalize program
program.result_columns = plan.result_columns;
program.table_references.extend(plan.table_references);
Ok(())
}
pub fn emit_fk_child_decrement_on_delete(
program: &mut ProgramBuilder,
resolver: &Resolver,
child_tbl: &BTreeTable,
child_table_name: &str,
child_cursor_id: usize,
child_rowid_reg: usize,
) -> crate::Result<()> {
for fk_ref in resolver.schema.resolved_fks_for_child(child_table_name)? {
if !fk_ref.fk.deferred {
continue;
}
// Fast path: if any FK column is NULL can't be a violation
let null_skip = program.allocate_label();
for cname in &fk_ref.child_cols {
let (pos, col) = child_tbl.get_column(cname).unwrap();
let src = if col.is_rowid_alias {
child_rowid_reg
} else {
let tmp = program.alloc_register();
program.emit_insn(Insn::Column {
cursor_id: child_cursor_id,
column: pos,
dest: tmp,
default: None,
});
tmp
};
program.emit_insn(Insn::IsNull {
reg: src,
target_pc: null_skip,
});
}
if fk_ref.parent_uses_rowid {
// Probe parent table by rowid
let parent_tbl = resolver
.schema
.get_btree_table(&fk_ref.fk.parent_table)
.expect("parent btree");
let pcur = open_read_table(program, &parent_tbl);
let (pos, col) = child_tbl.get_column(&fk_ref.child_cols[0]).unwrap();
let val = if col.is_rowid_alias {
child_rowid_reg
} else {
let tmp = program.alloc_register();
program.emit_insn(Insn::Column {
cursor_id: child_cursor_id,
column: pos,
dest: tmp,
default: None,
});
tmp
};
let tmpi = program.alloc_register();
program.emit_insn(Insn::Copy {
src_reg: val,
dst_reg: tmpi,
extra_amount: 0,
});
program.emit_insn(Insn::MustBeInt { reg: tmpi });
// NotExists jumps when the parent key is missing, so we decrement there
let missing = program.allocate_label();
let done = program.allocate_label();
program.emit_insn(Insn::NotExists {
cursor: pcur,
rowid_reg: tmpi,
target_pc: missing,
});
// Parent FOUND, no decrement
program.emit_insn(Insn::Close { cursor_id: pcur });
program.emit_insn(Insn::Goto { target_pc: done });
// Parent MISSING, decrement is guarded by FkIfZero to avoid underflow
program.preassign_label_to_next_insn(missing);
program.emit_insn(Insn::Close { cursor_id: pcur });
emit_guarded_fk_decrement(program, done);
program.preassign_label_to_next_insn(done);
} else {
// Probe parent unique index
let parent_tbl = resolver
.schema
.get_btree_table(&fk_ref.fk.parent_table)
.expect("parent btree");
let idx = fk_ref.parent_unique_index.as_ref().expect("unique index");
let icur = open_read_index(program, idx);
// Build probe from current child row
let n = fk_ref.child_cols.len();
let probe = program.alloc_registers(n);
for (i, cname) in fk_ref.child_cols.iter().enumerate() {
let (pos, col) = child_tbl.get_column(cname).unwrap();
let src = if col.is_rowid_alias {
child_rowid_reg
} else {
let r = program.alloc_register();
program.emit_insn(Insn::Column {
cursor_id: child_cursor_id,
column: pos,
dest: r,
default: None,
});
r
};
program.emit_insn(Insn::Copy {
src_reg: src,
dst_reg: probe + i,
extra_amount: 0,
});
}
program.emit_insn(Insn::Affinity {
start_reg: probe,
count: std::num::NonZeroUsize::new(n).unwrap(),
affinities: build_index_affinity_string(idx, &parent_tbl),
});
let ok = program.allocate_label();
program.emit_insn(Insn::Found {
cursor_id: icur,
target_pc: ok,
record_reg: probe,
num_regs: n,
});
program.emit_insn(Insn::Close { cursor_id: icur });
emit_guarded_fk_decrement(program, ok);
program.preassign_label_to_next_insn(ok);
program.emit_insn(Insn::Close { cursor_id: icur });
}
program.preassign_label_to_next_insn(null_skip);
}
Ok(())
}
fn emit_delete_insns(
connection: &Arc<Connection>,
program: &mut ProgramBuilder,
t_ctx: &mut TranslateCtx,
table_references: &mut TableReferences,
result_columns: &[super::plan::ResultSetColumn],
) -> Result<()> {
// we can either use this obviously safe raw pointer or we can clone it
let table_reference: *const JoinedTable = table_references.joined_tables().first().unwrap();
if unsafe { &*table_reference }
.virtual_table()
.is_some_and(|t| t.readonly())
{
return Err(crate::LimboError::ReadOnly);
}
let internal_id = unsafe { (*table_reference).internal_id };
let table_name = unsafe { &*table_reference }.table.get_name();
let cursor_id = match unsafe { &(*table_reference).op } {
Operation::Scan { .. } => program.resolve_cursor_id(&CursorKey::table(internal_id)),
Operation::Search(search) => match search {
Search::RowidEq { .. } | Search::Seek { index: None, .. } => {
program.resolve_cursor_id(&CursorKey::table(internal_id))
}
Search::Seek {
index: Some(index), ..
} => program.resolve_cursor_id(&CursorKey::index(internal_id, index.clone())),
},
};
let main_table_cursor_id = program.resolve_cursor_id(&CursorKey::table(internal_id));
// Emit the instructions to delete the row
let key_reg = program.alloc_register();
program.emit_insn(Insn::RowId {
cursor_id: main_table_cursor_id,
dest: key_reg,
});
if connection.foreign_keys_enabled() {
if let Some(table) = unsafe { &*table_reference }.btree() {
if t_ctx
.resolver
.schema
.any_resolved_fks_referencing(table_name)
{
emit_fk_delete_parent_existence_checks(
program,
&t_ctx.resolver,
table_name,
main_table_cursor_id,
key_reg,
)?;
}
if t_ctx.resolver.schema.has_child_fks(table_name) {
emit_fk_child_decrement_on_delete(
program,
&t_ctx.resolver,
&table,
table_name,
main_table_cursor_id,
key_reg,
)?;
}
}
}
if unsafe { &*table_reference }.virtual_table().is_some() {
let conflict_action = 0u16;
let start_reg = key_reg;
let new_rowid_reg = program.alloc_register();
program.emit_insn(Insn::Null {
dest: new_rowid_reg,
dest_end: None,
});
program.emit_insn(Insn::VUpdate {
cursor_id,
arg_count: 2,
start_reg,
conflict_action,
});
} else {
// Delete from all indexes before deleting from the main table.
let indexes = t_ctx.resolver.schema.indexes.get(table_name);
// Get the index that is being used to iterate the deletion loop, if there is one.
let iteration_index = unsafe { &*table_reference }.op.index();
// Get all indexes that are not the iteration index.
let other_indexes = indexes
.map(|indexes| {
indexes
.iter()
.filter(|index| {
iteration_index
.as_ref()
.is_none_or(|it_idx| !Arc::ptr_eq(it_idx, index))
})
.map(|index| {
(
index.clone(),
program
.resolve_cursor_id(&CursorKey::index(internal_id, index.clone())),
)
})
.collect::<Vec<_>>()
})
.unwrap_or_default();
for (index, index_cursor_id) in other_indexes {
let skip_delete_label = if index.where_clause.is_some() {
let where_copy = index
.bind_where_expr(Some(table_references), connection)
.expect("where clause to exist");
let skip_label = program.allocate_label();
let reg = program.alloc_register();
translate_expr_no_constant_opt(
program,
Some(table_references),
&where_copy,
reg,
&t_ctx.resolver,
NoConstantOptReason::RegisterReuse,
)?;
program.emit_insn(Insn::IfNot {
reg,
jump_if_null: true,
target_pc: skip_label,
});
Some(skip_label)
} else {
None
};
let num_regs = index.columns.len() + 1;
let start_reg = program.alloc_registers(num_regs);
// Emit columns that are part of the index
index
.columns
.iter()
.enumerate()
.for_each(|(reg_offset, column_index)| {
program.emit_column_or_rowid(
main_table_cursor_id,
column_index.pos_in_table,
start_reg + reg_offset,
);
});
program.emit_insn(Insn::RowId {
cursor_id: main_table_cursor_id,
dest: start_reg + num_regs - 1,
});
program.emit_insn(Insn::IdxDelete {
start_reg,
num_regs,
cursor_id: index_cursor_id,
raise_error_if_no_matching_entry: index.where_clause.is_none(),
});
if let Some(label) = skip_delete_label {
program.resolve_label(label, program.offset());
}
}
// Emit update in the CDC table if necessary (before DELETE updated the table)
if let Some(cdc_cursor_id) = t_ctx.cdc_cursor_id {
let rowid_reg = program.alloc_register();
program.emit_insn(Insn::RowId {
cursor_id: main_table_cursor_id,
dest: rowid_reg,
});
let cdc_has_before = program.capture_data_changes_mode().has_before();
let before_record_reg = if cdc_has_before {
Some(emit_cdc_full_record(
program,
unsafe { &*table_reference }.table.columns(),
main_table_cursor_id,
rowid_reg,
))
} else {
None
};
emit_cdc_insns(
program,
&t_ctx.resolver,
OperationMode::DELETE,
cdc_cursor_id,
rowid_reg,
before_record_reg,
None,
None,
table_name,
)?;
}
// Emit RETURNING results if specified (must be before DELETE)
if !result_columns.is_empty() {
// Get rowid for RETURNING
let rowid_reg = program.alloc_register();
program.emit_insn(Insn::RowId {
cursor_id: main_table_cursor_id,
dest: rowid_reg,
});
let cols_len = unsafe { &*table_reference }.columns().len();
// Allocate registers for column values
let columns_start_reg = program.alloc_registers(cols_len);
// Read all column values from the row to be deleted
for (i, _column) in unsafe { &*table_reference }.columns().iter().enumerate() {
program.emit_column_or_rowid(main_table_cursor_id, i, columns_start_reg + i);
}
// Emit RETURNING results using the values we just read
let value_registers = ReturningValueRegisters {
rowid_register: rowid_reg,
columns_start_register: columns_start_reg,
num_columns: cols_len,
};
emit_returning_results(program, result_columns, &value_registers)?;
}
program.emit_insn(Insn::Delete {
cursor_id: main_table_cursor_id,
table_name: table_name.to_string(),
is_part_of_update: false,
});
if let Some(index) = iteration_index {
let iteration_index_cursor =
program.resolve_cursor_id(&CursorKey::index(internal_id, index.clone()));
program.emit_insn(Insn::Delete {
cursor_id: iteration_index_cursor,
table_name: index.name.clone(),
is_part_of_update: false,
});
}
}
if let Some(limit_ctx) = t_ctx.limit_ctx {
program.emit_insn(Insn::DecrJumpZero {
reg: limit_ctx.reg_limit,
target_pc: t_ctx.label_main_loop_end.unwrap(),
})
}
Ok(())
}
#[instrument(skip_all, level = Level::DEBUG)]
fn emit_program_for_update(
connection: &Arc<Connection>,
resolver: &Resolver,
program: &mut ProgramBuilder,
mut plan: UpdatePlan,
after: impl FnOnce(&mut ProgramBuilder),
) -> Result<()> {
let mut t_ctx = TranslateCtx::new(
program,
resolver.schema,
resolver.symbol_table,
plan.table_references.joined_tables().len(),
);
let after_main_loop_label = program.allocate_label();
t_ctx.label_main_loop_end = Some(after_main_loop_label);
init_limit(program, &mut t_ctx, &plan.limit, &plan.offset)?;
// No rows will be read from source table loops if there is a constant false condition eg. WHERE 0
if plan.contains_constant_false_condition {
program.emit_insn(Insn::Goto {
target_pc: after_main_loop_label,
});
}
let ephemeral_plan = plan.ephemeral_plan.take();
let temp_cursor_id = ephemeral_plan.as_ref().map(|plan| {
let QueryDestination::EphemeralTable { cursor_id, .. } = &plan.query_destination else {
unreachable!()
};
*cursor_id
});
let has_ephemeral_table = ephemeral_plan.is_some();
let target_table = if let Some(ephemeral_plan) = ephemeral_plan {
let table = ephemeral_plan
.table_references
.joined_tables()
.first()
.unwrap()
.clone();
program.emit_insn(Insn::OpenEphemeral {
cursor_id: temp_cursor_id.unwrap(),
is_table: true,
});
program.incr_nesting();
emit_program_for_select(program, resolver, ephemeral_plan)?;
program.decr_nesting();
Arc::new(table)
} else {
Arc::new(
plan.table_references
.joined_tables()
.first()
.unwrap()
.clone(),
)
};
let mode = OperationMode::UPDATE(if has_ephemeral_table {
UpdateRowSource::PrebuiltEphemeralTable {
ephemeral_table_cursor_id: temp_cursor_id.expect(
"ephemeral table cursor id is always allocated if has_ephemeral_table is true",
),
target_table: target_table.clone(),
}
} else {
UpdateRowSource::Normal
});
// Initialize the main loop
init_loop(
program,
&mut t_ctx,
&plan.table_references,
&mut [],
None,
mode.clone(),
&plan.where_clause,
&[JoinOrderMember::default()],
&mut [],
)?;
// Prepare index cursors
let mut index_cursors = Vec::with_capacity(plan.indexes_to_update.len());
for index in &plan.indexes_to_update {
let index_cursor = if let Some(cursor) = program.resolve_cursor_id_safe(&CursorKey::index(
plan.table_references
.joined_tables()
.first()
.unwrap()
.internal_id,
index.clone(),
)) {
cursor
} else {
let cursor = program.alloc_cursor_id(CursorType::BTreeIndex(index.clone()));
program.emit_insn(Insn::OpenWrite {
cursor_id: cursor,
root_page: RegisterOrLiteral::Literal(index.root_page),
db: 0,
});
cursor
};
let record_reg = program.alloc_register();
index_cursors.push((index_cursor, record_reg));
}
// Open the main loop
open_loop(
program,
&mut t_ctx,
&plan.table_references,
&[JoinOrderMember::default()],
&plan.where_clause,
temp_cursor_id,
mode.clone(),
&mut [],
)?;
let target_table_cursor_id =
program.resolve_cursor_id(&CursorKey::table(target_table.internal_id));
let iteration_cursor_id = if has_ephemeral_table {
temp_cursor_id.unwrap()
} else {
target_table_cursor_id
};
// Emit update instructions
emit_update_insns(
connection,
&mut plan,
&t_ctx,
program,
index_cursors,
iteration_cursor_id,
target_table_cursor_id,
target_table,
)?;
// Close the main loop
close_loop(
program,
&mut t_ctx,
&plan.table_references,
&[JoinOrderMember::default()],
mode.clone(),
)?;
program.preassign_label_to_next_insn(after_main_loop_label);
after(program);
program.result_columns = plan.returning.unwrap_or_default();
program.table_references.extend(plan.table_references);
Ok(())
}
#[instrument(skip_all, level = Level::DEBUG)]
#[allow(clippy::too_many_arguments)]
/// Emits the instructions for the UPDATE loop.
///
/// `iteration_cursor_id` is the cursor id of the table that is being iterated over. This can be either the table itself, an index, or an ephemeral table (see [crate::translate::plan::UpdatePlan]).
///
/// `target_table_cursor_id` is the cursor id of the table that is being updated.
///
/// `target_table` is the table that is being updated.
fn emit_update_insns(
connection: &Arc<Connection>,
plan: &mut UpdatePlan,
t_ctx: &TranslateCtx,
program: &mut ProgramBuilder,
index_cursors: Vec<(usize, usize)>,
iteration_cursor_id: usize,
target_table_cursor_id: usize,
target_table: Arc<JoinedTable>,
) -> crate::Result<()> {
let internal_id = target_table.internal_id;
let loop_labels = t_ctx.labels_main_loop.first().unwrap();
let source_table = plan.table_references.joined_tables().first().unwrap();
let (index, is_virtual) = match &source_table.op {
Operation::Scan(Scan::BTreeTable { index, .. }) => (
index.as_ref().map(|index| {
(
index.clone(),
program.resolve_cursor_id(&CursorKey::index(internal_id, index.clone())),
)
}),
false,
),
Operation::Scan(_) => (None, target_table.virtual_table().is_some()),
Operation::Search(search) => match search {
&Search::RowidEq { .. } | Search::Seek { index: None, .. } => (None, false),
Search::Seek {
index: Some(index), ..
} => (
Some((
index.clone(),
program.resolve_cursor_id(&CursorKey::index(internal_id, index.clone())),
)),
false,
),
},
};
let beg = program.alloc_registers(
target_table.table.columns().len()
+ if is_virtual {
2 // two args before the relevant columns for VUpdate
} else {
1 // rowid reg
},
);
program.emit_insn(Insn::RowId {
cursor_id: iteration_cursor_id,
dest: beg,
});
// Check if rowid was provided (through INTEGER PRIMARY KEY as a rowid alias)
let rowid_alias_index = target_table
.table
.columns()
.iter()
.position(|c| c.is_rowid_alias);
let has_direct_rowid_update = plan
.set_clauses
.iter()
.any(|(idx, _)| *idx == ROWID_SENTINEL);
let has_user_provided_rowid = if let Some(index) = rowid_alias_index {
plan.set_clauses.iter().any(|(idx, _)| *idx == index)
} else {
has_direct_rowid_update
};
let rowid_set_clause_reg = if has_user_provided_rowid {
Some(program.alloc_register())
} else {
None
};
let not_exists_check_required =
has_user_provided_rowid || iteration_cursor_id != target_table_cursor_id;
let check_rowid_not_exists_label = if not_exists_check_required {
Some(program.allocate_label())
} else {
None
};
if not_exists_check_required {
program.emit_insn(Insn::NotExists {
cursor: target_table_cursor_id,
rowid_reg: beg,
target_pc: check_rowid_not_exists_label.unwrap(),
});
} else {
// if no rowid, we're done
program.emit_insn(Insn::IsNull {
reg: beg,
target_pc: t_ctx.label_main_loop_end.unwrap(),
});
}
if is_virtual {
program.emit_insn(Insn::Copy {
src_reg: beg,
dst_reg: beg + 1,
extra_amount: 0,
})
}
if let Some(offset) = t_ctx.reg_offset {
program.emit_insn(Insn::IfPos {
reg: offset,
target_pc: loop_labels.next,
decrement_by: 1,
});
}
let col_len = target_table.table.columns().len();
// we scan a column at a time, loading either the column's values, or the new value
// from the Set expression, into registers so we can emit a MakeRecord and update the row.
// we allocate 2C registers for "updates" as the structure of this column for CDC table is following:
// [C boolean values where true set for changed columns] [C values with updates where NULL is set for not-changed columns]
let cdc_updates_register = if program.capture_data_changes_mode().has_updates() {
Some(program.alloc_registers(2 * col_len))
} else {
None
};
let table_name = target_table.table.get_name();
let start = if is_virtual { beg + 2 } else { beg + 1 };
if has_direct_rowid_update {
if let Some((_, expr)) = plan.set_clauses.iter().find(|(i, _)| *i == ROWID_SENTINEL) {
let rowid_set_clause_reg = rowid_set_clause_reg.unwrap();
translate_expr(
program,
Some(&plan.table_references),
expr,
rowid_set_clause_reg,
&t_ctx.resolver,
)?;
program.emit_insn(Insn::MustBeInt {
reg: rowid_set_clause_reg,
});
}
}
for (idx, table_column) in target_table.table.columns().iter().enumerate() {
let target_reg = start + idx;
if let Some((col_idx, expr)) = plan.set_clauses.iter().find(|(i, _)| *i == idx) {
// Skip if this is the sentinel value
if *col_idx == ROWID_SENTINEL {
continue;
}
if has_user_provided_rowid
&& (table_column.primary_key || table_column.is_rowid_alias)
&& !is_virtual
{
let rowid_set_clause_reg = rowid_set_clause_reg.unwrap();
translate_expr(
program,
Some(&plan.table_references),
expr,
rowid_set_clause_reg,
&t_ctx.resolver,
)?;
program.emit_insn(Insn::MustBeInt {
reg: rowid_set_clause_reg,
});
program.emit_null(target_reg, None);
} else {
translate_expr(
program,
Some(&plan.table_references),
expr,
target_reg,
&t_ctx.resolver,
)?;
if table_column.notnull {
use crate::error::SQLITE_CONSTRAINT_NOTNULL;
program.emit_insn(Insn::HaltIfNull {
target_reg,
err_code: SQLITE_CONSTRAINT_NOTNULL,
description: format!(
"{}.{}",
table_name,
table_column
.name
.as_ref()
.expect("Column name must be present")
),
});
}
}
if let Some(cdc_updates_register) = cdc_updates_register {
let change_reg = cdc_updates_register + idx;
let value_reg = cdc_updates_register + col_len + idx;
program.emit_bool(true, change_reg);
program.mark_last_insn_constant();
let mut updated = false;
if let Some(ddl_query_for_cdc_update) = &plan.cdc_update_alter_statement {
if table_column.name.as_deref() == Some("sql") {
program.emit_string8(ddl_query_for_cdc_update.clone(), value_reg);
updated = true;
}
}
if !updated {
program.emit_insn(Insn::Copy {
src_reg: target_reg,
dst_reg: value_reg,
extra_amount: 0,
});
}
}
} else {
let column_idx_in_index = index.as_ref().and_then(|(idx, _)| {
idx.columns
.iter()
.position(|c| Some(&c.name) == table_column.name.as_ref())
});
// don't emit null for pkey of virtual tables. they require first two args
// before the 'record' to be explicitly non-null
if table_column.is_rowid_alias && !is_virtual {
program.emit_null(target_reg, None);
} else if is_virtual {
program.emit_insn(Insn::VColumn {
cursor_id: target_table_cursor_id,
column: idx,
dest: target_reg,
});
} else {
let cursor_id = *index
.as_ref()
.and_then(|(_, id)| {
if column_idx_in_index.is_some() {
Some(id)
} else {
None
}
})
.unwrap_or(&target_table_cursor_id);
program.emit_column_or_rowid(
cursor_id,
column_idx_in_index.unwrap_or(idx),
target_reg,
);
}
if let Some(cdc_updates_register) = cdc_updates_register {
let change_bit_reg = cdc_updates_register + idx;
let value_reg = cdc_updates_register + col_len + idx;
program.emit_bool(false, change_bit_reg);
program.mark_last_insn_constant();
program.emit_null(value_reg, None);
program.mark_last_insn_constant();
}
}
}
if connection.foreign_keys_enabled() {
let rowid_new_reg = rowid_set_clause_reg.unwrap_or(beg);
if let Some(table_btree) = target_table.table.btree() {
stabilize_new_row_for_fk(
program,
&table_btree,
&plan.set_clauses,
target_table_cursor_id,
start,
rowid_new_reg,
)?;
if t_ctx.resolver.schema.has_child_fks(table_name) {
// Child-side checks:
// this ensures updated row still satisfies child FKs that point OUT from this table
emit_fk_child_update_counters(
program,
&t_ctx.resolver,
&table_btree,
table_name,
target_table_cursor_id,
start,
rowid_new_reg,
&plan
.set_clauses
.iter()
.map(|(i, _)| *i)
.collect::<HashSet<_>>(),
)?;
}
// Parent-side checks:
// We only need to do work if the referenced key (the parent key) might change.
// we detect that by comparing OLD vs NEW primary key representation
// then run parent FK checks only when it actually changes.
if t_ctx
.resolver
.schema
.any_resolved_fks_referencing(table_name)
{
emit_parent_key_change_checks(
program,
&t_ctx.resolver,
&table_btree,
plan.indexes_to_update.iter(),
target_table_cursor_id,
beg,
start,
rowid_new_reg,
rowid_set_clause_reg,
&plan.set_clauses,
)?;
}
}
}
for (index, (idx_cursor_id, record_reg)) in plan.indexes_to_update.iter().zip(&index_cursors) {
// We need to know whether or not the OLD values satisfied the predicate on the
// partial index, so we can know whether or not to delete the old index entry,
// as well as whether or not the NEW values satisfy the predicate, to determine whether
// or not to insert a new index entry for a partial index
let (old_satisfies_where, new_satisfies_where) = if index.where_clause.is_some() {
// This means that we need to bind the column references to a copy of the index Expr,
// so we can emit Insn::Column instructions and refer to the old values.
let where_clause = index
.bind_where_expr(Some(&mut plan.table_references), connection)
.expect("where clause to exist");
let old_satisfied_reg = program.alloc_register();
translate_expr_no_constant_opt(
program,
Some(&plan.table_references),
&where_clause,
old_satisfied_reg,
&t_ctx.resolver,
NoConstantOptReason::RegisterReuse,
)?;
// grab a new copy of the original where clause from the index
let mut new_where = index
.where_clause
.as_ref()
.expect("checked where clause to exist")
.clone();
// Now we need to rewrite the Expr::Id and Expr::Qualified/Expr::RowID (from a copy of the original, un-bound `where` expr),
// to refer to the new values, which are already loaded into registers starting at `start`.
rewrite_where_for_update_registers(
&mut new_where,
target_table.table.columns(),
start,
rowid_set_clause_reg.unwrap_or(beg),
)?;
let new_satisfied_reg = program.alloc_register();
translate_expr_no_constant_opt(
program,
None,
&new_where,
new_satisfied_reg,
&t_ctx.resolver,
NoConstantOptReason::RegisterReuse,
)?;
// now we have two registers that tell us whether or not the old and new values satisfy
// the partial index predicate, and we can use those to decide whether or not to
// delete/insert a new index entry for this partial index.
(Some(old_satisfied_reg), Some(new_satisfied_reg))
} else {
(None, None)
};
let mut skip_delete_label = None;
let mut skip_insert_label = None;
// Handle deletion for partial indexes
if let Some(old_satisfied) = old_satisfies_where {
skip_delete_label = Some(program.allocate_label());
// If the old values don't satisfy the WHERE clause, skip the delete
program.emit_insn(Insn::IfNot {
reg: old_satisfied,
target_pc: skip_delete_label.unwrap(),
jump_if_null: true,
});
}
// Delete old index entry
let num_regs = index.columns.len() + 1;
let delete_start_reg = program.alloc_registers(num_regs);
for (reg_offset, column_index) in index.columns.iter().enumerate() {
program.emit_column_or_rowid(
target_table_cursor_id,
column_index.pos_in_table,
delete_start_reg + reg_offset,
);
}
program.emit_insn(Insn::RowId {
cursor_id: target_table_cursor_id,
dest: delete_start_reg + num_regs - 1,
});
program.emit_insn(Insn::IdxDelete {
start_reg: delete_start_reg,
num_regs,
cursor_id: *idx_cursor_id,
raise_error_if_no_matching_entry: true,
});
// Resolve delete skip label if it exists
if let Some(label) = skip_delete_label {
program.resolve_label(label, program.offset());
}
// Check if we should insert into partial index
if let Some(new_satisfied) = new_satisfies_where {
skip_insert_label = Some(program.allocate_label());
// If the new values don't satisfy the WHERE clause, skip the idx insert
program.emit_insn(Insn::IfNot {
reg: new_satisfied,
target_pc: skip_insert_label.unwrap(),
jump_if_null: true,
});
}
// Build new index entry
let num_cols = index.columns.len();
let idx_start_reg = program.alloc_registers(num_cols + 1);
let rowid_reg = rowid_set_clause_reg.unwrap_or(beg);
for (i, col) in index.columns.iter().enumerate() {
let col_in_table = target_table
.table
.columns()
.get(col.pos_in_table)
.expect("column index out of bounds");
program.emit_insn(Insn::Copy {
src_reg: if col_in_table.is_rowid_alias {
rowid_reg
} else {
start + col.pos_in_table
},
dst_reg: idx_start_reg + i,
extra_amount: 0,
});
}
// last register is the rowid
program.emit_insn(Insn::Copy {
src_reg: rowid_reg,
dst_reg: idx_start_reg + num_cols,
extra_amount: 0,
});
program.emit_insn(Insn::MakeRecord {
start_reg: idx_start_reg,
count: num_cols + 1,
dest_reg: *record_reg,
index_name: Some(index.name.clone()),
affinity_str: None,
});
// Handle unique constraint
if index.unique {
let aff = index
.columns
.iter()
.map(|ic| {
target_table.table.columns()[ic.pos_in_table]
.affinity()
.aff_mask()
})
.collect::<String>();
program.emit_insn(Insn::Affinity {
start_reg: idx_start_reg,
count: NonZeroUsize::new(num_cols).expect("nonzero col count"),
affinities: aff,
});
let constraint_check = program.allocate_label();
// check if the record already exists in the index for unique indexes and abort if so
program.emit_insn(Insn::NoConflict {
cursor_id: *idx_cursor_id,
target_pc: constraint_check,
record_reg: idx_start_reg,
num_regs: num_cols,
});
let idx_rowid_reg = program.alloc_register();
program.emit_insn(Insn::IdxRowId {
cursor_id: *idx_cursor_id,
dest: idx_rowid_reg,
});
// Skip over the UNIQUE constraint failure if the existing row is the one that we are currently changing
program.emit_insn(Insn::Eq {
lhs: beg,
rhs: idx_rowid_reg,
target_pc: constraint_check,
flags: CmpInsFlags::default(),
collation: program.curr_collation(),
});
let column_names = index.columns.iter().enumerate().fold(
String::with_capacity(50),
|mut accum, (idx, col)| {
if idx > 0 {
accum.push_str(", ");
}
accum.push_str(table_name);
accum.push('.');
accum.push_str(&col.name);
accum
},
);
program.emit_insn(Insn::Halt {
err_code: SQLITE_CONSTRAINT_PRIMARYKEY,
description: column_names,
});
program.preassign_label_to_next_insn(constraint_check);
}
// Insert the index entry
program.emit_insn(Insn::IdxInsert {
cursor_id: *idx_cursor_id,
record_reg: *record_reg,
unpacked_start: Some(idx_start_reg),
unpacked_count: Some((num_cols + 1) as u16),
flags: IdxInsertFlags::new().nchange(true),
});
// Resolve insert skip label if it exists
if let Some(label) = skip_insert_label {
program.resolve_label(label, program.offset());
}
}
if let Some(btree_table) = target_table.table.btree() {
if btree_table.is_strict {
program.emit_insn(Insn::TypeCheck {
start_reg: start,
count: col_len,
check_generated: true,
table_reference: Arc::clone(&btree_table),
});
}
if has_user_provided_rowid {
let record_label = program.allocate_label();
let target_reg = rowid_set_clause_reg.unwrap();
program.emit_insn(Insn::Eq {
lhs: target_reg,
rhs: beg,
target_pc: record_label,
flags: CmpInsFlags::default(),
collation: program.curr_collation(),
});
program.emit_insn(Insn::NotExists {
cursor: target_table_cursor_id,
rowid_reg: target_reg,
target_pc: record_label,
});
let description = if let Some(idx) = rowid_alias_index {
String::from(table_name)
+ "."
+ target_table
.table
.columns()
.get(idx)
.unwrap()
.name
.as_ref()
.map_or("", |v| v)
} else {
String::from(table_name) + ".rowid"
};
program.emit_insn(Insn::Halt {
err_code: SQLITE_CONSTRAINT_PRIMARYKEY,
description,
});
program.preassign_label_to_next_insn(record_label);
}
let record_reg = program.alloc_register();
let affinity_str = target_table
.table
.columns()
.iter()
.map(|col| col.affinity().aff_mask())
.collect::<String>();
program.emit_insn(Insn::MakeRecord {
start_reg: start,
count: col_len,
dest_reg: record_reg,
index_name: None,
affinity_str: Some(affinity_str),
});
if not_exists_check_required {
program.emit_insn(Insn::NotExists {
cursor: target_table_cursor_id,
rowid_reg: beg,
target_pc: check_rowid_not_exists_label.unwrap(),
});
}
// create alias for CDC rowid after the change (will differ from cdc_rowid_before_reg only in case of UPDATE with change in rowid alias)
let cdc_rowid_after_reg = rowid_set_clause_reg.unwrap_or(beg);
// create separate register with rowid before UPDATE for CDC
let cdc_rowid_before_reg = if t_ctx.cdc_cursor_id.is_some() {
let cdc_rowid_before_reg = program.alloc_register();
if has_user_provided_rowid {
program.emit_insn(Insn::RowId {
cursor_id: target_table_cursor_id,
dest: cdc_rowid_before_reg,
});
Some(cdc_rowid_before_reg)
} else {
Some(cdc_rowid_after_reg)
}
} else {
None
};
// create full CDC record before update if necessary
let cdc_before_reg = if program.capture_data_changes_mode().has_before() {
Some(emit_cdc_full_record(
program,
target_table.table.columns(),
target_table_cursor_id,
cdc_rowid_before_reg.expect("cdc_rowid_before_reg must be set"),
))
} else {
None
};
// If we are updating the rowid, we cannot rely on overwrite on the
// Insert instruction to update the cell. We need to first delete the current cell
// and later insert the updated record
if not_exists_check_required {
program.emit_insn(Insn::Delete {
cursor_id: target_table_cursor_id,
table_name: table_name.to_string(),
is_part_of_update: true,
});
}
program.emit_insn(Insn::Insert {
cursor: target_table_cursor_id,
key_reg: rowid_set_clause_reg.unwrap_or(beg),
record_reg,
flag: if not_exists_check_required {
// The previous Insn::NotExists and Insn::Delete seek to the old rowid,
// so to insert a new user-provided rowid, we need to seek to the correct place.
InsertFlags::new().require_seek().update_rowid_change()
} else {
InsertFlags::new()
},
table_name: target_table.identifier.clone(),
});
// Emit RETURNING results if specified
if let Some(returning_columns) = &plan.returning {
if !returning_columns.is_empty() {
let value_registers = ReturningValueRegisters {
rowid_register: rowid_set_clause_reg.unwrap_or(beg),
columns_start_register: start,
num_columns: col_len,
};
emit_returning_results(program, returning_columns, &value_registers)?;
}
}
// create full CDC record after update if necessary
let cdc_after_reg = if program.capture_data_changes_mode().has_after() {
Some(emit_cdc_patch_record(
program,
&target_table.table,
start,
record_reg,
cdc_rowid_after_reg,
))
} else {
None
};
let cdc_updates_record = if let Some(cdc_updates_register) = cdc_updates_register {
let record_reg = program.alloc_register();
program.emit_insn(Insn::MakeRecord {
start_reg: cdc_updates_register,
count: 2 * col_len,
dest_reg: record_reg,
index_name: None,
affinity_str: None,
});
Some(record_reg)
} else {
None
};
// emit actual CDC instructions for write to the CDC table
if let Some(cdc_cursor_id) = t_ctx.cdc_cursor_id {
let cdc_rowid_before_reg =
cdc_rowid_before_reg.expect("cdc_rowid_before_reg must be set");
if has_user_provided_rowid {
emit_cdc_insns(
program,
&t_ctx.resolver,
OperationMode::DELETE,
cdc_cursor_id,
cdc_rowid_before_reg,
cdc_before_reg,
None,
None,
table_name,
)?;
emit_cdc_insns(
program,
&t_ctx.resolver,
OperationMode::INSERT,
cdc_cursor_id,
cdc_rowid_after_reg,
cdc_after_reg,
None,
None,
table_name,
)?;
} else {
emit_cdc_insns(
program,
&t_ctx.resolver,
OperationMode::UPDATE(if plan.ephemeral_plan.is_some() {
UpdateRowSource::PrebuiltEphemeralTable {
ephemeral_table_cursor_id: iteration_cursor_id,
target_table: target_table.clone(),
}
} else {
UpdateRowSource::Normal
}),
cdc_cursor_id,
cdc_rowid_before_reg,
cdc_before_reg,
cdc_after_reg,
cdc_updates_record,
table_name,
)?;
}
}
} else if target_table.virtual_table().is_some() {
let arg_count = col_len + 2;
program.emit_insn(Insn::VUpdate {
cursor_id: target_table_cursor_id,
arg_count,
start_reg: beg,
conflict_action: 0u16,
});
}
if let Some(limit_ctx) = t_ctx.limit_ctx {
program.emit_insn(Insn::DecrJumpZero {
reg: limit_ctx.reg_limit,
target_pc: t_ctx.label_main_loop_end.unwrap(),
})
}
// TODO(pthorpe): handle RETURNING clause
if let Some(label) = check_rowid_not_exists_label {
program.preassign_label_to_next_insn(label);
}
Ok(())
}
pub fn prepare_cdc_if_necessary(
program: &mut ProgramBuilder,
schema: &Schema,
changed_table_name: &str,
) -> Result<Option<(usize, Arc<BTreeTable>)>> {
let mode = program.capture_data_changes_mode();
let cdc_table = mode.table();
let Some(cdc_table) = cdc_table else {
return Ok(None);
};
if changed_table_name == cdc_table {
return Ok(None);
}
let Some(turso_cdc_table) = schema.get_table(cdc_table) else {
crate::bail_parse_error!("no such table: {}", cdc_table);
};
let Some(cdc_btree) = turso_cdc_table.btree().clone() else {
crate::bail_parse_error!("no such table: {}", cdc_table);
};
let cursor_id = program.alloc_cursor_id(CursorType::BTreeTable(cdc_btree.clone()));
program.emit_insn(Insn::OpenWrite {
cursor_id,
root_page: cdc_btree.root_page.into(),
db: 0, // todo(sivukhin): fix DB number when write will be supported for ATTACH
});
Ok(Some((cursor_id, cdc_btree)))
}
pub fn emit_cdc_patch_record(
program: &mut ProgramBuilder,
table: &Table,
columns_reg: usize,
record_reg: usize,
rowid_reg: usize,
) -> usize {
let columns = table.columns();
let rowid_alias_position = columns.iter().position(|x| x.is_rowid_alias);
if let Some(rowid_alias_position) = rowid_alias_position {
let record_reg = program.alloc_register();
program.emit_insn(Insn::Copy {
src_reg: rowid_reg,
dst_reg: columns_reg + rowid_alias_position,
extra_amount: 0,
});
let affinity_str = table
.columns()
.iter()
.map(|col| col.affinity().aff_mask())
.collect::<String>();
program.emit_insn(Insn::MakeRecord {
start_reg: columns_reg,
count: table.columns().len(),
dest_reg: record_reg,
index_name: None,
affinity_str: Some(affinity_str),
});
record_reg
} else {
record_reg
}
}
pub fn emit_cdc_full_record(
program: &mut ProgramBuilder,
columns: &[Column],
table_cursor_id: usize,
rowid_reg: usize,
) -> usize {
let columns_reg = program.alloc_registers(columns.len() + 1);
for (i, column) in columns.iter().enumerate() {
if column.is_rowid_alias {
program.emit_insn(Insn::Copy {
src_reg: rowid_reg,
dst_reg: columns_reg + 1 + i,
extra_amount: 0,
});
} else {
program.emit_column_or_rowid(table_cursor_id, i, columns_reg + 1 + i);
}
}
let affinity_str = columns
.iter()
.map(|col| col.affinity().aff_mask())
.collect::<String>();
program.emit_insn(Insn::MakeRecord {
start_reg: columns_reg + 1,
count: columns.len(),
dest_reg: columns_reg,
index_name: None,
affinity_str: Some(affinity_str),
});
columns_reg
}
#[allow(clippy::too_many_arguments)]
pub fn emit_cdc_insns(
program: &mut ProgramBuilder,
resolver: &Resolver,
operation_mode: OperationMode,
cdc_cursor_id: usize,
rowid_reg: usize,
before_record_reg: Option<usize>,
after_record_reg: Option<usize>,
updates_record_reg: Option<usize>,
table_name: &str,
) -> Result<()> {
// (change_id INTEGER PRIMARY KEY AUTOINCREMENT, change_time INTEGER, change_type INTEGER, table_name TEXT, id, before BLOB, after BLOB, updates BLOB)
let turso_cdc_registers = program.alloc_registers(8);
program.emit_insn(Insn::Null {
dest: turso_cdc_registers,
dest_end: None,
});
program.mark_last_insn_constant();
let Some(unixepoch_fn) = resolver.resolve_function("unixepoch", 0) else {
bail_parse_error!("no function {}", "unixepoch");
};
let unixepoch_fn_ctx = crate::function::FuncCtx {
func: unixepoch_fn,
arg_count: 0,
};
program.emit_insn(Insn::Function {
constant_mask: 0,
start_reg: 0,
dest: turso_cdc_registers + 1,
func: unixepoch_fn_ctx,
});
let change_type = match operation_mode {
OperationMode::INSERT => 1,
OperationMode::UPDATE { .. } | OperationMode::SELECT => 0,
OperationMode::DELETE => -1,
};
program.emit_int(change_type, turso_cdc_registers + 2);
program.mark_last_insn_constant();
program.emit_string8(table_name.to_string(), turso_cdc_registers + 3);
program.mark_last_insn_constant();
program.emit_insn(Insn::Copy {
src_reg: rowid_reg,
dst_reg: turso_cdc_registers + 4,
extra_amount: 0,
});
if let Some(before_record_reg) = before_record_reg {
program.emit_insn(Insn::Copy {
src_reg: before_record_reg,
dst_reg: turso_cdc_registers + 5,
extra_amount: 0,
});
} else {
program.emit_null(turso_cdc_registers + 5, None);
program.mark_last_insn_constant();
}
if let Some(after_record_reg) = after_record_reg {
program.emit_insn(Insn::Copy {
src_reg: after_record_reg,
dst_reg: turso_cdc_registers + 6,
extra_amount: 0,
});
} else {
program.emit_null(turso_cdc_registers + 6, None);
program.mark_last_insn_constant();
}
if let Some(updates_record_reg) = updates_record_reg {
program.emit_insn(Insn::Copy {
src_reg: updates_record_reg,
dst_reg: turso_cdc_registers + 7,
extra_amount: 0,
});
} else {
program.emit_null(turso_cdc_registers + 7, None);
program.mark_last_insn_constant();
}
let rowid_reg = program.alloc_register();
program.emit_insn(Insn::NewRowid {
cursor: cdc_cursor_id,
rowid_reg,
prev_largest_reg: 0, // todo(sivukhin): properly set value here from sqlite_sequence table when AUTOINCREMENT will be properly implemented in Turso
});
let record_reg = program.alloc_register();
program.emit_insn(Insn::MakeRecord {
start_reg: turso_cdc_registers,
count: 8,
dest_reg: record_reg,
index_name: None,
affinity_str: None,
});
program.emit_insn(Insn::Insert {
cursor: cdc_cursor_id,
key_reg: rowid_reg,
record_reg,
flag: InsertFlags::new(),
table_name: "".to_string(),
});
Ok(())
}
/// Initialize the limit/offset counters and registers.
/// In case of compound SELECTs, the limit counter is initialized only once,
/// hence [LimitCtx::initialize_counter] being false in those cases.
fn init_limit(
program: &mut ProgramBuilder,
t_ctx: &mut TranslateCtx,
limit: &Option<Box<Expr>>,
offset: &Option<Box<Expr>>,
) -> Result<()> {
if t_ctx.limit_ctx.is_none() && limit.is_some() {
t_ctx.limit_ctx = Some(LimitCtx::new(program));
}
let Some(limit_ctx) = &t_ctx.limit_ctx else {
return Ok(());
};
if limit_ctx.initialize_counter {
if let Some(expr) = limit {
match expr.as_ref() {
Expr::Literal(Literal::Numeric(n)) => {
if let Ok(value) = n.parse::<i64>() {
program.add_comment(program.offset(), "LIMIT counter");
program.emit_insn(Insn::Integer {
value,
dest: limit_ctx.reg_limit,
});
} else {
program.emit_insn(Insn::Real {
value: n.parse::<f64>().unwrap(),
dest: limit_ctx.reg_limit,
});
program.add_comment(program.offset(), "LIMIT counter");
program.emit_insn(Insn::MustBeInt {
reg: limit_ctx.reg_limit,
});
}
}
_ => {
let r = limit_ctx.reg_limit;
_ = translate_expr(program, None, expr, r, &t_ctx.resolver);
program.emit_insn(Insn::MustBeInt { reg: r });
}
}
}
}
if t_ctx.reg_offset.is_none() {
if let Some(expr) = offset {
let offset_reg = program.alloc_register();
t_ctx.reg_offset = Some(offset_reg);
match expr.as_ref() {
Expr::Literal(Literal::Numeric(n)) => {
if let Ok(value) = n.parse::<i64>() {
program.emit_insn(Insn::Integer {
value,
dest: offset_reg,
});
} else {
let value = n.parse::<f64>()?;
program.emit_insn(Insn::Real {
value,
dest: limit_ctx.reg_limit,
});
program.emit_insn(Insn::MustBeInt {
reg: limit_ctx.reg_limit,
});
}
}
_ => {
_ = translate_expr(program, None, expr, offset_reg, &t_ctx.resolver);
}
}
program.add_comment(program.offset(), "OFFSET counter");
program.emit_insn(Insn::MustBeInt { reg: offset_reg });
let combined_reg = program.alloc_register();
t_ctx.reg_limit_offset_sum = Some(combined_reg);
program.add_comment(program.offset(), "OFFSET + LIMIT");
program.emit_insn(Insn::OffsetLimit {
limit_reg: limit_ctx.reg_limit,
offset_reg,
combined_reg,
});
}
}
// exit early if LIMIT 0
let main_loop_end = t_ctx
.label_main_loop_end
.expect("label_main_loop_end must be set before init_limit");
program.emit_insn(Insn::IfNot {
reg: limit_ctx.reg_limit,
target_pc: main_loop_end,
jump_if_null: false,
});
Ok(())
}
/// We have `Expr`s which have *not* had column references bound to them,
/// so they are in the state of Expr::Id/Expr::Qualified, etc, and instead of binding Expr::Column
/// we need to bind Expr::Register, as we have already loaded the *new* column values from the
/// UPDATE statement into registers starting at `columns_start_reg`, which we want to reference.
fn rewrite_where_for_update_registers(
expr: &mut Expr,
columns: &[Column],
columns_start_reg: usize,
rowid_reg: usize,
) -> Result<WalkControl> {
walk_expr_mut(expr, &mut |e: &mut Expr| -> Result<WalkControl> {
match e {
Expr::Qualified(_, col) | Expr::DoublyQualified(_, _, col) => {
let normalized = normalize_ident(col.as_str());
if let Some((idx, c)) = columns.iter().enumerate().find(|(_, c)| {
c.name
.as_ref()
.is_some_and(|n| n.eq_ignore_ascii_case(&normalized))
}) {
if c.is_rowid_alias {
*e = Expr::Register(rowid_reg);
} else {
*e = Expr::Register(columns_start_reg + idx);
}
}
}
Expr::Id(name) => {
let normalized = normalize_ident(name.as_str());
if ROWID_STRS
.iter()
.any(|s| s.eq_ignore_ascii_case(&normalized))
{
*e = Expr::Register(rowid_reg);
} else if let Some((idx, c)) = columns.iter().enumerate().find(|(_, c)| {
c.name
.as_ref()
.is_some_and(|n| n.eq_ignore_ascii_case(&normalized))
}) {
if c.is_rowid_alias {
*e = Expr::Register(rowid_reg);
} else {
*e = Expr::Register(columns_start_reg + idx);
}
}
}
Expr::RowId { .. } => {
*e = Expr::Register(rowid_reg);
}
_ => {}
}
Ok(WalkControl::Continue)
})
}