limbo/core/translate/insert.rs

548 lines
19 KiB
Rust

use std::ops::Deref;
use std::rc::Rc;
use limbo_sqlite3_parser::ast::{
DistinctNames, Expr, InsertBody, OneSelect, QualifiedName, ResolveType, ResultColumn, With,
};
use crate::error::SQLITE_CONSTRAINT_PRIMARYKEY;
use crate::schema::Table;
use crate::util::normalize_ident;
use crate::vdbe::builder::{ProgramBuilderOpts, QueryMode};
use crate::vdbe::BranchOffset;
use crate::{
schema::{Column, Schema},
translate::expr::translate_expr,
vdbe::{
builder::{CursorType, ProgramBuilder},
insn::Insn,
},
SymbolTable,
};
use crate::{Result, VirtualTable};
use super::emitter::Resolver;
#[allow(clippy::too_many_arguments)]
pub fn translate_insert(
query_mode: QueryMode,
schema: &Schema,
with: &Option<With>,
on_conflict: &Option<ResolveType>,
tbl_name: &QualifiedName,
columns: &Option<DistinctNames>,
body: &InsertBody,
_returning: &Option<Vec<ResultColumn>>,
syms: &SymbolTable,
) -> Result<ProgramBuilder> {
let mut program = ProgramBuilder::new(ProgramBuilderOpts {
query_mode,
num_cursors: 1,
approx_num_insns: 30,
approx_num_labels: 5,
});
if with.is_some() {
crate::bail_parse_error!("WITH clause is not supported");
}
if on_conflict.is_some() {
crate::bail_parse_error!("ON CONFLICT clause is not supported");
}
let table_name = &tbl_name.name;
let table = match schema.get_table(table_name.0.as_str()) {
Some(table) => table,
None => crate::bail_corrupt_error!("Parse error: no such table: {}", table_name),
};
let resolver = Resolver::new(syms);
if let Some(virtual_table) = &table.virtual_table() {
translate_virtual_table_insert(
&mut program,
virtual_table.clone(),
columns,
body,
on_conflict,
&resolver,
)?;
return Ok(program);
}
let init_label = program.allocate_label();
program.emit_insn(Insn::Init {
target_pc: init_label,
});
let start_offset = program.offset();
let Some(btree_table) = table.btree() else {
crate::bail_corrupt_error!("Parse error: no such table: {}", table_name);
};
if !btree_table.has_rowid {
crate::bail_parse_error!("INSERT into WITHOUT ROWID table is not supported");
}
let cursor_id = program.alloc_cursor_id(
Some(table_name.0.clone()),
CursorType::BTreeTable(btree_table.clone()),
);
let root_page = btree_table.root_page;
let values = match body {
InsertBody::Select(select, None) => match &select.body.select.deref() {
OneSelect::Values(values) => values,
_ => todo!(),
},
_ => todo!(),
};
let column_mappings = resolve_columns_for_insert(&table, columns, values)?;
// Check if rowid was provided (through INTEGER PRIMARY KEY as a rowid alias)
let rowid_alias_index = btree_table.columns.iter().position(|c| c.is_rowid_alias);
let has_user_provided_rowid = {
assert_eq!(column_mappings.len(), btree_table.columns.len());
if let Some(index) = rowid_alias_index {
column_mappings[index].value_index.is_some()
} else {
false
}
};
// allocate a register for each column in the table. if not provided by user, they will simply be set as null.
// allocate an extra register for rowid regardless of whether user provided a rowid alias column.
let num_cols = btree_table.columns.len();
let rowid_reg = program.alloc_registers(num_cols + 1);
let column_registers_start = rowid_reg + 1;
let rowid_alias_reg = {
if has_user_provided_rowid {
Some(column_registers_start + rowid_alias_index.unwrap())
} else {
None
}
};
let record_register = program.alloc_register();
let halt_label = program.allocate_label();
let mut loop_start_offset = BranchOffset::Offset(0);
let inserting_multiple_rows = values.len() > 1;
// Multiple rows - use coroutine for value population
if inserting_multiple_rows {
let yield_reg = program.alloc_register();
let jump_on_definition_label = program.allocate_label();
program.emit_insn(Insn::InitCoroutine {
yield_reg,
jump_on_definition: jump_on_definition_label,
start_offset: program.offset().add(1u32),
});
for value in values {
populate_column_registers(
&mut program,
value,
&column_mappings,
column_registers_start,
true,
rowid_reg,
&resolver,
)?;
program.emit_insn(Insn::Yield {
yield_reg,
end_offset: halt_label,
});
}
program.emit_insn(Insn::EndCoroutine { yield_reg });
program.resolve_label(jump_on_definition_label, program.offset());
program.emit_insn(Insn::OpenWriteAsync {
cursor_id,
root_page,
});
program.emit_insn(Insn::OpenWriteAwait {});
// Main loop
// FIXME: rollback is not implemented. E.g. if you insert 2 rows and one fails to unique constraint violation,
// the other row will still be inserted.
loop_start_offset = program.offset();
program.emit_insn(Insn::Yield {
yield_reg,
end_offset: halt_label,
});
} else {
// Single row - populate registers directly
program.emit_insn(Insn::OpenWriteAsync {
cursor_id,
root_page,
});
program.emit_insn(Insn::OpenWriteAwait {});
populate_column_registers(
&mut program,
&values[0],
&column_mappings,
column_registers_start,
false,
rowid_reg,
&resolver,
)?;
}
// Common record insertion logic for both single and multiple rows
let check_rowid_is_integer_label = rowid_alias_reg.and(Some(program.allocate_label()));
if let Some(reg) = rowid_alias_reg {
// for the row record, the rowid alias column (INTEGER PRIMARY KEY) is always set to NULL
// and its value is copied to the rowid register. in the case where a single row is inserted,
// the value is written directly to the rowid register (see populate_column_registers()).
// again, not sure why this only happens in the single row case, but let's mimic sqlite.
// in the single row case we save a Copy instruction, but in the multiple rows case we do
// it here in the loop.
if inserting_multiple_rows {
program.emit_insn(Insn::Copy {
src_reg: reg,
dst_reg: rowid_reg,
amount: 0, // TODO: rename 'amount' to something else; amount==0 means 1
});
// for the row record, the rowid alias column is always set to NULL
program.emit_insn(Insn::SoftNull { reg });
}
// the user provided rowid value might itself be NULL. If it is, we create a new rowid on the next instruction.
program.emit_insn(Insn::NotNull {
reg: rowid_reg,
target_pc: check_rowid_is_integer_label.unwrap(),
});
}
// Create new rowid if a) not provided by user or b) provided by user but is NULL
program.emit_insn(Insn::NewRowid {
cursor: cursor_id,
rowid_reg,
prev_largest_reg: 0,
});
if let Some(must_be_int_label) = check_rowid_is_integer_label {
program.resolve_label(must_be_int_label, program.offset());
// If the user provided a rowid, it must be an integer.
program.emit_insn(Insn::MustBeInt { reg: rowid_reg });
}
// Check uniqueness constraint for rowid if it was provided by user.
// When the DB allocates it there are no need for separate uniqueness checks.
if has_user_provided_rowid {
let make_record_label = program.allocate_label();
program.emit_insn(Insn::NotExists {
cursor: cursor_id,
rowid_reg,
target_pc: make_record_label,
});
let rowid_column_name = if let Some(index) = rowid_alias_index {
btree_table
.columns
.get(index)
.unwrap()
.name
.as_ref()
.expect("column name is None")
} else {
"rowid"
};
program.emit_insn(Insn::Halt {
err_code: SQLITE_CONSTRAINT_PRIMARYKEY,
description: format!("{}.{}", table_name.0, rowid_column_name),
});
program.resolve_label(make_record_label, program.offset());
}
// Create and insert the record
program.emit_insn(Insn::MakeRecord {
start_reg: column_registers_start,
count: num_cols,
dest_reg: record_register,
});
program.emit_insn(Insn::InsertAsync {
cursor: cursor_id,
key_reg: rowid_reg,
record_reg: record_register,
flag: 0,
});
program.emit_insn(Insn::InsertAwait { cursor_id });
if inserting_multiple_rows {
// For multiple rows, loop back
program.emit_insn(Insn::Goto {
target_pc: loop_start_offset,
});
}
program.resolve_label(halt_label, program.offset());
program.emit_insn(Insn::Halt {
err_code: 0,
description: String::new(),
});
program.resolve_label(init_label, program.offset());
program.emit_insn(Insn::Transaction { write: true });
program.emit_constant_insns();
program.emit_insn(Insn::Goto {
target_pc: start_offset,
});
Ok(program)
}
#[derive(Debug)]
/// Represents how a column should be populated during an INSERT.
/// Contains both the column definition and optionally the index into the VALUES tuple.
struct ColumnMapping<'a> {
/// Reference to the column definition from the table schema
column: &'a Column,
/// If Some(i), use the i-th value from the VALUES tuple
/// If None, use NULL (column was not specified in INSERT statement)
value_index: Option<usize>,
/// The default value for the column, if defined
default_value: Option<&'a Expr>,
}
/// Resolves how each column in a table should be populated during an INSERT.
/// Returns a Vec of ColumnMapping, one for each column in the table's schema.
///
/// For each column, specifies:
/// 1. The column definition (type, constraints, etc)
/// 2. Where to get the value from:
/// - Some(i) -> use i-th value from the VALUES tuple
/// - None -> use NULL (column wasn't specified in INSERT)
///
/// Two cases are handled:
/// 1. No column list specified (INSERT INTO t VALUES ...):
/// - Values are assigned to columns in table definition order
/// - If fewer values than columns, remaining columns map to None
/// 2. Column list specified (INSERT INTO t (col1, col3) VALUES ...):
/// - Named columns map to their corresponding value index
/// - Unspecified columns map to None
fn resolve_columns_for_insert<'a>(
table: &'a Table,
columns: &Option<DistinctNames>,
values: &[Vec<Expr>],
) -> Result<Vec<ColumnMapping<'a>>> {
if values.is_empty() {
crate::bail_parse_error!("no values to insert");
}
let table_columns = &table.columns();
// Case 1: No columns specified - map values to columns in order
if columns.is_none() {
let num_values = values[0].len();
if num_values > table_columns.len() {
crate::bail_parse_error!(
"table {} has {} columns but {} values were supplied",
&table.get_name(),
table_columns.len(),
num_values
);
}
// Verify all value tuples have same length
for value in values.iter().skip(1) {
if value.len() != num_values {
crate::bail_parse_error!("all VALUES must have the same number of terms");
}
}
// Map each column to either its corresponding value index or None
return Ok(table_columns
.iter()
.enumerate()
.map(|(i, col)| ColumnMapping {
column: col,
value_index: if i < num_values { Some(i) } else { None },
default_value: col.default.as_ref(),
})
.collect());
}
// Case 2: Columns specified - map named columns to their values
let mut mappings: Vec<_> = table_columns
.iter()
.map(|col| ColumnMapping {
column: col,
value_index: None,
default_value: col.default.as_ref(),
})
.collect();
// Map each named column to its value index
for (value_index, column_name) in columns.as_ref().unwrap().iter().enumerate() {
let column_name = normalize_ident(column_name.0.as_str());
let table_index = table_columns.iter().position(|c| {
c.name
.as_ref()
.map_or(false, |name| name.eq_ignore_ascii_case(&column_name))
});
if table_index.is_none() {
crate::bail_parse_error!(
"table {} has no column named {}",
&table.get_name(),
column_name
);
}
mappings[table_index.unwrap()].value_index = Some(value_index);
}
Ok(mappings)
}
/// Populates the column registers with values for a single row
fn populate_column_registers(
program: &mut ProgramBuilder,
value: &[Expr],
column_mappings: &[ColumnMapping],
column_registers_start: usize,
inserting_multiple_rows: bool,
rowid_reg: usize,
resolver: &Resolver,
) -> Result<()> {
for (i, mapping) in column_mappings.iter().enumerate() {
let target_reg = column_registers_start + i;
// Column has a value in the VALUES tuple
if let Some(value_index) = mapping.value_index {
// When inserting a single row, SQLite writes the value provided for the rowid alias column (INTEGER PRIMARY KEY)
// directly into the rowid register and writes a NULL into the rowid alias column. Not sure why this only happens
// in the single row case, but let's copy it.
let write_directly_to_rowid_reg =
mapping.column.is_rowid_alias && !inserting_multiple_rows;
let reg = if write_directly_to_rowid_reg {
rowid_reg
} else {
target_reg
};
translate_expr(
program,
None,
value.get(value_index).expect("value index out of bounds"),
reg,
resolver,
)?;
if write_directly_to_rowid_reg {
program.emit_insn(Insn::SoftNull { reg: target_reg });
}
} else if let Some(default_expr) = mapping.default_value {
translate_expr(program, None, default_expr, target_reg, resolver)?;
} else {
// Column was not specified as has no DEFAULT - use NULL if it is nullable, otherwise error
// Rowid alias columns can be NULL because we will autogenerate a rowid in that case.
let is_nullable = !mapping.column.primary_key || mapping.column.is_rowid_alias;
if is_nullable {
program.emit_insn(Insn::Null {
dest: target_reg,
dest_end: None,
});
program.mark_last_insn_constant();
} else {
crate::bail_parse_error!(
"column {} is not nullable",
mapping.column.name.as_ref().expect("column name is None")
);
}
}
}
Ok(())
}
fn translate_virtual_table_insert(
program: &mut ProgramBuilder,
virtual_table: Rc<VirtualTable>,
columns: &Option<DistinctNames>,
body: &InsertBody,
on_conflict: &Option<ResolveType>,
resolver: &Resolver,
) -> Result<()> {
let init_label = program.allocate_label();
program.emit_insn(Insn::Init {
target_pc: init_label,
});
let start_offset = program.offset();
let values = match body {
InsertBody::Select(select, None) => match &select.body.select.deref() {
OneSelect::Values(values) => values,
_ => crate::bail_parse_error!("Virtual tables only support VALUES clause in INSERT"),
},
InsertBody::DefaultValues => &vec![],
_ => crate::bail_parse_error!("Unsupported INSERT body for virtual tables"),
};
let table = Table::Virtual(virtual_table.clone());
let column_mappings = resolve_columns_for_insert(&table, columns, values)?;
let value_registers_start = program.alloc_registers(values[0].len());
for (i, expr) in values[0].iter().enumerate() {
translate_expr(program, None, expr, value_registers_start + i, resolver)?;
}
/* *
* Inserts for virtual tables are done in a single step.
* argv[0] = (NULL for insert)
* argv[1] = (NULL for insert)
* argv[2..] = column values
* */
let rowid_reg = program.alloc_registers(column_mappings.len() + 3);
let insert_rowid_reg = rowid_reg + 1; // argv[1] = insert_rowid
let data_start_reg = rowid_reg + 2; // argv[2..] = column values
program.emit_insn(Insn::Null {
dest: rowid_reg,
dest_end: None,
});
program.emit_insn(Insn::Null {
dest: insert_rowid_reg,
dest_end: None,
});
for (i, mapping) in column_mappings.iter().enumerate() {
let target_reg = data_start_reg + i;
if let Some(value_index) = mapping.value_index {
program.emit_insn(Insn::Copy {
src_reg: value_registers_start + value_index,
dst_reg: target_reg,
amount: 1,
});
} else {
program.emit_insn(Insn::Null {
dest: target_reg,
dest_end: None,
});
}
}
let conflict_action = on_conflict.as_ref().map(|c| c.bit_value()).unwrap_or(0) as u16;
let cursor_id = program.alloc_cursor_id(
Some(virtual_table.name.clone()),
CursorType::VirtualTable(virtual_table.clone()),
);
program.emit_insn(Insn::VUpdate {
cursor_id,
arg_count: column_mappings.len() + 2,
start_reg: rowid_reg,
vtab_ptr: virtual_table.implementation.as_ref().ctx as usize,
conflict_action,
});
let halt_label = program.allocate_label();
program.emit_insn(Insn::Halt {
err_code: 0,
description: String::new(),
});
program.resolve_label(halt_label, program.offset());
program.resolve_label(init_label, program.offset());
program.emit_insn(Insn::Goto {
target_pc: start_offset,
});
Ok(())
}