rusqlite/src/vtab/mod.rs

1014 lines
30 KiB
Rust

//! Create virtual tables.
//!
//! Follow these steps to create your own virtual table:
//! 1. Write implemenation of `VTab` and `VTabCursor` traits.
//! 2. Create an instance of the `Module` structure specialized for `VTab` impl.
//! from step 1.
//! 3. Register your `Module` structure using `Connection.create_module`.
//! 4. Run a `CREATE VIRTUAL TABLE` command that specifies the new module in the
//! `USING` clause.
//!
//! (See [SQLite doc](http://sqlite.org/vtab.html))
use std::borrow::Cow::{self, Borrowed, Owned};
use std::ffi::CString;
use std::marker::PhantomData;
use std::marker::Sync;
use std::os::raw::{c_char, c_int, c_void};
use std::ptr;
use std::slice;
use crate::context::set_result;
use crate::error::error_from_sqlite_code;
use crate::ffi;
pub use crate::ffi::{sqlite3_vtab, sqlite3_vtab_cursor};
use crate::types::{FromSql, FromSqlError, ToSql, ValueRef};
use crate::{str_to_cstring, Connection, Error, InnerConnection, Result};
// let conn: Connection = ...;
// let mod: Module = ...; // VTab builder
// conn.create_module("module", mod);
//
// conn.execute("CREATE VIRTUAL TABLE foo USING module(...)");
// \-> Module::xcreate
// |-> let vtab: VTab = ...; // on the heap
// \-> conn.declare_vtab("CREATE TABLE foo (...)");
// conn = Connection::open(...);
// \-> Module::xconnect
// |-> let vtab: VTab = ...; // on the heap
// \-> conn.declare_vtab("CREATE TABLE foo (...)");
//
// conn.close();
// \-> vtab.xdisconnect
// conn.execute("DROP TABLE foo");
// \-> vtab.xDestroy
//
// let stmt = conn.prepare("SELECT ... FROM foo WHERE ...");
// \-> vtab.xbestindex
// stmt.query().next();
// \-> vtab.xopen
// |-> let cursor: VTabCursor = ...; // on the heap
// |-> cursor.xfilter or xnext
// |-> cursor.xeof
// \-> if not eof { cursor.column or xrowid } else { cursor.xclose }
//
// db: *mut ffi::sqlite3 => VTabConnection
// module: *const ffi::sqlite3_module => Module
// aux: *mut c_void => Module::Aux
// ffi::sqlite3_vtab => VTab
// ffi::sqlite3_vtab_cursor => VTabCursor
/// Virtual table module
///
/// (See [SQLite doc](https://sqlite.org/c3ref/module.html))
#[repr(C)]
pub struct Module<T: VTab> {
base: ffi::sqlite3_module,
phantom: PhantomData<T>,
}
unsafe impl<T: VTab> Sync for Module<T> {}
/// Create a read-only virtual table implementation.
///
/// Step 2 of [Creating New Virtual Table Implementations](https://sqlite.org/vtab.html#creating_new_virtual_table_implementations).
pub fn read_only_module<T: CreateVTab>(version: c_int) -> Module<T> {
// The xConnect and xCreate methods do the same thing, but they must be
// different so that the virtual table is not an eponymous virtual table.
let ffi_module = ffi::sqlite3_module {
iVersion: version,
xCreate: Some(rust_create::<T>),
xConnect: Some(rust_connect::<T>),
xBestIndex: Some(rust_best_index::<T>),
xDisconnect: Some(rust_disconnect::<T>),
xDestroy: Some(rust_destroy::<T>),
xOpen: Some(rust_open::<T>),
xClose: Some(rust_close::<T::Cursor>),
xFilter: Some(rust_filter::<T::Cursor>),
xNext: Some(rust_next::<T::Cursor>),
xEof: Some(rust_eof::<T::Cursor>),
xColumn: Some(rust_column::<T::Cursor>),
xRowid: Some(rust_rowid::<T::Cursor>),
xUpdate: None,
xBegin: None,
xSync: None,
xCommit: None,
xRollback: None,
xFindFunction: None,
xRename: None,
xSavepoint: None,
xRelease: None,
xRollbackTo: None,
#[cfg(any(feature = "bundled", feature = "vtab_v3"))]
xShadowName: None,
};
Module {
base: ffi_module,
phantom: PhantomData::<T>,
}
}
/// Create an eponymous only virtual table implementation.
///
/// Step 2 of [Creating New Virtual Table Implementations](https://sqlite.org/vtab.html#creating_new_virtual_table_implementations).
pub fn eponymous_only_module<T: VTab>(version: c_int) -> Module<T> {
// A virtual table is eponymous if its xCreate method is the exact same function
// as the xConnect method For eponymous-only virtual tables, the xCreate
// method is NULL
let ffi_module = ffi::sqlite3_module {
iVersion: version,
xCreate: None,
xConnect: Some(rust_connect::<T>),
xBestIndex: Some(rust_best_index::<T>),
xDisconnect: Some(rust_disconnect::<T>),
xDestroy: None,
xOpen: Some(rust_open::<T>),
xClose: Some(rust_close::<T::Cursor>),
xFilter: Some(rust_filter::<T::Cursor>),
xNext: Some(rust_next::<T::Cursor>),
xEof: Some(rust_eof::<T::Cursor>),
xColumn: Some(rust_column::<T::Cursor>),
xRowid: Some(rust_rowid::<T::Cursor>),
xUpdate: None,
xBegin: None,
xSync: None,
xCommit: None,
xRollback: None,
xFindFunction: None,
xRename: None,
xSavepoint: None,
xRelease: None,
xRollbackTo: None,
#[cfg(any(feature = "bundled", feature = "vtab_v3"))]
xShadowName: None,
};
Module {
base: ffi_module,
phantom: PhantomData::<T>,
}
}
pub struct VTabConnection(*mut ffi::sqlite3);
impl VTabConnection {
// TODO sqlite3_vtab_config (http://sqlite.org/c3ref/vtab_config.html)
// TODO sqlite3_vtab_on_conflict (http://sqlite.org/c3ref/vtab_on_conflict.html)
/// Get access to the underlying SQLite database connection handle.
///
/// # Warning
///
/// You should not need to use this function. If you do need to, please
/// [open an issue on the rusqlite repository](https://github.com/jgallagher/rusqlite/issues) and describe
/// your use case. This function is unsafe because it gives you raw access
/// to the SQLite connection, and what you do with it could impact the
/// safety of this `Connection`.
pub unsafe fn handle(&mut self) -> *mut ffi::sqlite3 {
self.0
}
}
/// Virtual table instance trait.
///
/// Implementations must be like:
/// ```rust,ignore
/// #[repr(C)]
/// struct MyTab {
/// /// Base class. Must be first
/// base: ffi::sqlite3_vtab,
/// /* Virtual table implementations will typically add additional fields */
/// }
/// ```
///
/// (See [SQLite doc](https://sqlite.org/c3ref/vtab.html))
pub trait VTab: Sized {
type Aux;
type Cursor: VTabCursor;
/// Establish a new connection to an existing virtual table.
///
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xconnect_method))
fn connect(
db: &mut VTabConnection,
aux: Option<&Self::Aux>,
args: &[&[u8]],
) -> Result<(String, Self)>;
/// Determine the best way to access the virtual table.
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xbestindex_method))
fn best_index(&self, info: &mut IndexInfo) -> Result<()>;
/// Create a new cursor used for accessing a virtual table.
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xopen_method))
fn open(&self) -> Result<Self::Cursor>;
}
/// Non-eponymous virtual table instance trait.
///
/// (See [SQLite doc](https://sqlite.org/c3ref/vtab.html))
pub trait CreateVTab: VTab {
/// Create a new instance of a virtual table in response to a CREATE VIRTUAL
/// TABLE statement. The `db` parameter is a pointer to the SQLite
/// database connection that is executing the CREATE VIRTUAL TABLE
/// statement.
///
/// Call `connect` by default.
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xcreate_method))
fn create(
db: &mut VTabConnection,
aux: Option<&Self::Aux>,
args: &[&[u8]],
) -> Result<(String, Self)> {
Self::connect(db, aux, args)
}
/// Destroy the underlying table implementation. This method undoes the work
/// of `create`.
///
/// Do nothing by default.
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xdestroy_method))
fn destroy(&self) -> Result<()> {
Ok(())
}
}
bitflags! {
#[doc = "Index constraint operator."]
#[repr(C)]
pub struct IndexConstraintOp: ::std::os::raw::c_uchar {
const SQLITE_INDEX_CONSTRAINT_EQ = 2;
const SQLITE_INDEX_CONSTRAINT_GT = 4;
const SQLITE_INDEX_CONSTRAINT_LE = 8;
const SQLITE_INDEX_CONSTRAINT_LT = 16;
const SQLITE_INDEX_CONSTRAINT_GE = 32;
const SQLITE_INDEX_CONSTRAINT_MATCH = 64;
}
}
/// Pass information into and receive the reply from the `VTab.best_index`
/// method.
///
/// (See [SQLite doc](http://sqlite.org/c3ref/index_info.html))
pub struct IndexInfo(*mut ffi::sqlite3_index_info);
impl IndexInfo {
/// Record WHERE clause constraints.
pub fn constraints(&self) -> IndexConstraintIter<'_> {
let constraints =
unsafe { slice::from_raw_parts((*self.0).aConstraint, (*self.0).nConstraint as usize) };
IndexConstraintIter {
iter: constraints.iter(),
}
}
/// Information about the ORDER BY clause.
pub fn order_bys(&self) -> OrderByIter<'_> {
let order_bys =
unsafe { slice::from_raw_parts((*self.0).aOrderBy, (*self.0).nOrderBy as usize) };
OrderByIter {
iter: order_bys.iter(),
}
}
/// Number of terms in the ORDER BY clause
pub fn num_of_order_by(&self) -> usize {
unsafe { (*self.0).nOrderBy as usize }
}
pub fn constraint_usage(&mut self, constraint_idx: usize) -> IndexConstraintUsage<'_> {
let constraint_usages = unsafe {
slice::from_raw_parts_mut((*self.0).aConstraintUsage, (*self.0).nConstraint as usize)
};
IndexConstraintUsage(&mut constraint_usages[constraint_idx])
}
/// Number used to identify the index
pub fn set_idx_num(&mut self, idx_num: c_int) {
unsafe {
(*self.0).idxNum = idx_num;
}
}
/// True if output is already ordered
pub fn set_order_by_consumed(&mut self, order_by_consumed: bool) {
unsafe {
(*self.0).orderByConsumed = if order_by_consumed { 1 } else { 0 };
}
}
/// Estimated cost of using this index
pub fn set_estimated_cost(&mut self, estimated_ost: f64) {
unsafe {
(*self.0).estimatedCost = estimated_ost;
}
}
/// Estimated number of rows returned
#[cfg(feature = "bundled")] // SQLite >= 3.8.2
pub fn set_estimated_rows(&mut self, estimated_rows: i64) {
unsafe {
(*self.0).estimatedRows = estimated_rows;
}
}
// TODO idxFlags
// TODO colUsed
// TODO sqlite3_vtab_collation (http://sqlite.org/c3ref/vtab_collation.html)
}
pub struct IndexConstraintIter<'a> {
iter: slice::Iter<'a, ffi::sqlite3_index_constraint>,
}
impl<'a> Iterator for IndexConstraintIter<'a> {
type Item = IndexConstraint<'a>;
fn next(&mut self) -> Option<IndexConstraint<'a>> {
self.iter.next().map(|raw| IndexConstraint(raw))
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
/// WHERE clause constraint
pub struct IndexConstraint<'a>(&'a ffi::sqlite3_index_constraint);
impl<'a> IndexConstraint<'a> {
/// Column constrained. -1 for ROWID
pub fn column(&self) -> c_int {
self.0.iColumn
}
/// Constraint operator
pub fn operator(&self) -> IndexConstraintOp {
IndexConstraintOp::from_bits_truncate(self.0.op)
}
/// True if this constraint is usable
pub fn is_usable(&self) -> bool {
self.0.usable != 0
}
}
/// Information about what parameters to pass to `VTabCursor.filter`.
pub struct IndexConstraintUsage<'a>(&'a mut ffi::sqlite3_index_constraint_usage);
impl<'a> IndexConstraintUsage<'a> {
/// if `argv_index` > 0, constraint is part of argv to `VTabCursor.filter`
pub fn set_argv_index(&mut self, argv_index: c_int) {
self.0.argvIndex = argv_index;
}
/// if `omit`, do not code a test for this constraint
pub fn set_omit(&mut self, omit: bool) {
self.0.omit = if omit { 1 } else { 0 };
}
}
pub struct OrderByIter<'a> {
iter: slice::Iter<'a, ffi::sqlite3_index_info_sqlite3_index_orderby>,
}
impl<'a> Iterator for OrderByIter<'a> {
type Item = OrderBy<'a>;
fn next(&mut self) -> Option<OrderBy<'a>> {
self.iter.next().map(|raw| OrderBy(raw))
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
/// A column of the ORDER BY clause.
pub struct OrderBy<'a>(&'a ffi::sqlite3_index_info_sqlite3_index_orderby);
impl<'a> OrderBy<'a> {
/// Column number
pub fn column(&self) -> c_int {
self.0.iColumn
}
/// True for DESC. False for ASC.
pub fn is_order_by_desc(&self) -> bool {
self.0.desc != 0
}
}
/// Virtual table cursor trait.
///
/// Implementations must be like:
/// ```rust,ignore
/// #[repr(C)]
/// struct MyTabCursor {
/// /// Base class. Must be first
/// base: ffi::sqlite3_vtab_cursor,
/// /* Virtual table implementations will typically add additional fields */
/// }
/// ```
///
/// (See [SQLite doc](https://sqlite.org/c3ref/vtab_cursor.html))
pub trait VTabCursor: Sized {
/// Begin a search of a virtual table.
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xfilter_method))
fn filter(&mut self, idx_num: c_int, idx_str: Option<&str>, args: &Values<'_>) -> Result<()>;
/// Advance cursor to the next row of a result set initiated by `filter`.
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xnext_method))
fn next(&mut self) -> Result<()>;
/// Must return `false` if the cursor currently points to a valid row of
/// data, or `true` otherwise.
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xeof_method))
fn eof(&self) -> bool;
/// Find the value for the `i`-th column of the current row.
/// `i` is zero-based so the first column is numbered 0.
/// May return its result back to SQLite using one of the specified `ctx`.
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xcolumn_method))
fn column(&self, ctx: &mut Context, i: c_int) -> Result<()>;
/// Return the rowid of row that the cursor is currently pointing at.
/// (See [SQLite doc](https://sqlite.org/vtab.html#the_xrowid_method))
fn rowid(&self) -> Result<i64>;
}
/// Context is used by `VTabCursor.column` to specify the cell value.
pub struct Context(*mut ffi::sqlite3_context);
impl Context {
pub fn set_result<T: ToSql>(&mut self, value: &T) -> Result<()> {
let t = value.to_sql()?;
unsafe { set_result(self.0, &t) };
Ok(())
}
// TODO sqlite3_vtab_nochange (http://sqlite.org/c3ref/vtab_nochange.html)
}
/// Wrapper to `VTabCursor.filter` arguments, the values requested by
/// `VTab.best_index`.
pub struct Values<'a> {
args: &'a [*mut ffi::sqlite3_value],
}
impl<'a> Values<'a> {
pub fn len(&self) -> usize {
self.args.len()
}
pub fn is_empty(&self) -> bool {
self.args.is_empty()
}
pub fn get<T: FromSql>(&self, idx: usize) -> Result<T> {
let arg = self.args[idx];
let value = unsafe { ValueRef::from_value(arg) };
FromSql::column_result(value).map_err(|err| match err {
FromSqlError::InvalidType => Error::InvalidFilterParameterType(idx, value.data_type()),
FromSqlError::Other(err) => {
Error::FromSqlConversionFailure(idx, value.data_type(), err)
}
FromSqlError::OutOfRange(i) => Error::IntegralValueOutOfRange(idx, i),
#[cfg(feature = "i128_blob")]
FromSqlError::InvalidI128Size(_) => Error::InvalidColumnType(idx, value.data_type()),
})
}
// `sqlite3_value_type` returns `SQLITE_NULL` for pointer.
// So it seems not possible to enhance `ValueRef::from_value`.
#[cfg(feature = "array")]
pub(crate) fn get_array(&self, idx: usize) -> Result<Option<array::Array>> {
use crate::types::Value;
let arg = self.args[idx];
let ptr = unsafe { ffi::sqlite3_value_pointer(arg, array::ARRAY_TYPE) };
if ptr.is_null() {
Ok(None)
} else {
Ok(Some(unsafe {
let rc = array::Array::from_raw(ptr as *const Vec<Value>);
let array = rc.clone();
array::Array::into_raw(rc); // don't consume it
array
}))
}
}
pub fn iter(&self) -> ValueIter<'_> {
ValueIter {
iter: self.args.iter(),
}
}
}
impl<'a> IntoIterator for &'a Values<'a> {
type IntoIter = ValueIter<'a>;
type Item = ValueRef<'a>;
fn into_iter(self) -> ValueIter<'a> {
self.iter()
}
}
pub struct ValueIter<'a> {
iter: slice::Iter<'a, *mut ffi::sqlite3_value>,
}
impl<'a> Iterator for ValueIter<'a> {
type Item = ValueRef<'a>;
fn next(&mut self) -> Option<ValueRef<'a>> {
self.iter
.next()
.map(|&raw| unsafe { ValueRef::from_value(raw) })
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl Connection {
/// Register a virtual table implementation.
///
/// Step 3 of [Creating New Virtual Table Implementations](https://sqlite.org/vtab.html#creating_new_virtual_table_implementations).
pub fn create_module<T: VTab>(
&self,
module_name: &str,
module: &Module<T>,
aux: Option<T::Aux>,
) -> Result<()> {
self.db.borrow_mut().create_module(module_name, module, aux)
}
}
impl InnerConnection {
fn create_module<T: VTab>(
&mut self,
module_name: &str,
module: &Module<T>,
aux: Option<T::Aux>,
) -> Result<()> {
let c_name = str_to_cstring(module_name)?;
let r = match aux {
Some(aux) => {
let boxed_aux: *mut T::Aux = Box::into_raw(Box::new(aux));
unsafe {
ffi::sqlite3_create_module_v2(
self.db(),
c_name.as_ptr(),
&module.base,
boxed_aux as *mut c_void,
Some(free_boxed_value::<T::Aux>),
)
}
}
None => unsafe {
ffi::sqlite3_create_module_v2(
self.db(),
c_name.as_ptr(),
&module.base,
ptr::null_mut(),
None,
)
},
};
self.decode_result(r)
}
}
/// Escape double-quote (`"`) character occurences by doubling them (`""`).
pub fn escape_double_quote(identifier: &str) -> Cow<'_, str> {
if identifier.contains('"') {
// escape quote by doubling them
Owned(identifier.replace("\"", "\"\""))
} else {
Borrowed(identifier)
}
}
/// Dequote string
pub fn dequote(s: &str) -> &str {
if s.len() < 2 {
return s;
}
match s.bytes().next() {
Some(b) if b == b'"' || b == b'\'' => match s.bytes().rev().next() {
Some(e) if e == b => &s[1..s.len() - 1],
_ => s,
},
_ => s,
}
}
/// The boolean can be one of:
/// ```text
/// 1 yes true on
/// 0 no false off
/// ```
pub fn parse_boolean(s: &str) -> Option<bool> {
if s.eq_ignore_ascii_case("yes")
|| s.eq_ignore_ascii_case("on")
|| s.eq_ignore_ascii_case("true")
|| s.eq("1")
{
Some(true)
} else if s.eq_ignore_ascii_case("no")
|| s.eq_ignore_ascii_case("off")
|| s.eq_ignore_ascii_case("false")
|| s.eq("0")
{
Some(false)
} else {
None
}
}
// FIXME copy/paste from function.rs
unsafe extern "C" fn free_boxed_value<T>(p: *mut c_void) {
let _: Box<T> = Box::from_raw(p as *mut T);
}
unsafe extern "C" fn rust_create<T>(
db: *mut ffi::sqlite3,
aux: *mut c_void,
argc: c_int,
argv: *const *const c_char,
pp_vtab: *mut *mut ffi::sqlite3_vtab,
err_msg: *mut *mut c_char,
) -> c_int
where
T: CreateVTab,
{
use std::error::Error as StdError;
use std::ffi::CStr;
use std::slice;
let mut conn = VTabConnection(db);
let aux = aux as *mut T::Aux;
let args = slice::from_raw_parts(argv, argc as usize);
let vec = args
.iter()
.map(|&cs| CStr::from_ptr(cs).to_bytes()) // FIXME .to_str() -> Result<&str, Utf8Error>
.collect::<Vec<_>>();
match T::create(&mut conn, aux.as_ref(), &vec[..]) {
Ok((sql, vtab)) => match ::std::ffi::CString::new(sql) {
Ok(c_sql) => {
let rc = ffi::sqlite3_declare_vtab(db, c_sql.as_ptr());
if rc == ffi::SQLITE_OK {
let boxed_vtab: *mut T = Box::into_raw(Box::new(vtab));
*pp_vtab = boxed_vtab as *mut ffi::sqlite3_vtab;
ffi::SQLITE_OK
} else {
let err = error_from_sqlite_code(rc, None);
*err_msg = mprintf(err.description());
rc
}
}
Err(err) => {
*err_msg = mprintf(err.description());
ffi::SQLITE_ERROR
}
},
Err(Error::SqliteFailure(err, s)) => {
if let Some(s) = s {
*err_msg = mprintf(&s);
}
err.extended_code
}
Err(err) => {
*err_msg = mprintf(err.description());
ffi::SQLITE_ERROR
}
}
}
unsafe extern "C" fn rust_connect<T>(
db: *mut ffi::sqlite3,
aux: *mut c_void,
argc: c_int,
argv: *const *const c_char,
pp_vtab: *mut *mut ffi::sqlite3_vtab,
err_msg: *mut *mut c_char,
) -> c_int
where
T: VTab,
{
use std::error::Error as StdError;
use std::ffi::CStr;
use std::slice;
let mut conn = VTabConnection(db);
let aux = aux as *mut T::Aux;
let args = slice::from_raw_parts(argv, argc as usize);
let vec = args
.iter()
.map(|&cs| CStr::from_ptr(cs).to_bytes()) // FIXME .to_str() -> Result<&str, Utf8Error>
.collect::<Vec<_>>();
match T::connect(&mut conn, aux.as_ref(), &vec[..]) {
Ok((sql, vtab)) => match ::std::ffi::CString::new(sql) {
Ok(c_sql) => {
let rc = ffi::sqlite3_declare_vtab(db, c_sql.as_ptr());
if rc == ffi::SQLITE_OK {
let boxed_vtab: *mut T = Box::into_raw(Box::new(vtab));
*pp_vtab = boxed_vtab as *mut ffi::sqlite3_vtab;
ffi::SQLITE_OK
} else {
let err = error_from_sqlite_code(rc, None);
*err_msg = mprintf(err.description());
rc
}
}
Err(err) => {
*err_msg = mprintf(err.description());
ffi::SQLITE_ERROR
}
},
Err(Error::SqliteFailure(err, s)) => {
if let Some(s) = s {
*err_msg = mprintf(&s);
}
err.extended_code
}
Err(err) => {
*err_msg = mprintf(err.description());
ffi::SQLITE_ERROR
}
}
}
unsafe extern "C" fn rust_best_index<T>(
vtab: *mut ffi::sqlite3_vtab,
info: *mut ffi::sqlite3_index_info,
) -> c_int
where
T: VTab,
{
use std::error::Error as StdError;
let vt = vtab as *mut T;
let mut idx_info = IndexInfo(info);
match (*vt).best_index(&mut idx_info) {
Ok(_) => ffi::SQLITE_OK,
Err(Error::SqliteFailure(err, s)) => {
if let Some(err_msg) = s {
set_err_msg(vtab, &err_msg);
}
err.extended_code
}
Err(err) => {
set_err_msg(vtab, err.description());
ffi::SQLITE_ERROR
}
}
}
unsafe extern "C" fn rust_disconnect<T>(vtab: *mut ffi::sqlite3_vtab) -> c_int
where
T: VTab,
{
if vtab.is_null() {
return ffi::SQLITE_OK;
}
let vtab = vtab as *mut T;
let _: Box<T> = Box::from_raw(vtab);
ffi::SQLITE_OK
}
unsafe extern "C" fn rust_destroy<T>(vtab: *mut ffi::sqlite3_vtab) -> c_int
where
T: CreateVTab,
{
use std::error::Error as StdError;
if vtab.is_null() {
return ffi::SQLITE_OK;
}
let vt = vtab as *mut T;
match (*vt).destroy() {
Ok(_) => {
let _: Box<T> = Box::from_raw(vt);
ffi::SQLITE_OK
}
Err(Error::SqliteFailure(err, s)) => {
if let Some(err_msg) = s {
set_err_msg(vtab, &err_msg);
}
err.extended_code
}
Err(err) => {
set_err_msg(vtab, err.description());
ffi::SQLITE_ERROR
}
}
}
unsafe extern "C" fn rust_open<T>(
vtab: *mut ffi::sqlite3_vtab,
pp_cursor: *mut *mut ffi::sqlite3_vtab_cursor,
) -> c_int
where
T: VTab,
{
use std::error::Error as StdError;
let vt = vtab as *mut T;
match (*vt).open() {
Ok(cursor) => {
let boxed_cursor: *mut T::Cursor = Box::into_raw(Box::new(cursor));
*pp_cursor = boxed_cursor as *mut ffi::sqlite3_vtab_cursor;
ffi::SQLITE_OK
}
Err(Error::SqliteFailure(err, s)) => {
if let Some(err_msg) = s {
set_err_msg(vtab, &err_msg);
}
err.extended_code
}
Err(err) => {
set_err_msg(vtab, err.description());
ffi::SQLITE_ERROR
}
}
}
unsafe extern "C" fn rust_close<C>(cursor: *mut ffi::sqlite3_vtab_cursor) -> c_int
where
C: VTabCursor,
{
let cr = cursor as *mut C;
let _: Box<C> = Box::from_raw(cr);
ffi::SQLITE_OK
}
unsafe extern "C" fn rust_filter<C>(
cursor: *mut ffi::sqlite3_vtab_cursor,
idx_num: c_int,
idx_str: *const c_char,
argc: c_int,
argv: *mut *mut ffi::sqlite3_value,
) -> c_int
where
C: VTabCursor,
{
use std::ffi::CStr;
use std::slice;
use std::str;
let idx_name = if idx_str.is_null() {
None
} else {
let c_slice = CStr::from_ptr(idx_str).to_bytes();
Some(str::from_utf8_unchecked(c_slice))
};
let args = slice::from_raw_parts_mut(argv, argc as usize);
let values = Values { args };
let cr = cursor as *mut C;
cursor_error(cursor, (*cr).filter(idx_num, idx_name, &values))
}
unsafe extern "C" fn rust_next<C>(cursor: *mut ffi::sqlite3_vtab_cursor) -> c_int
where
C: VTabCursor,
{
let cr = cursor as *mut C;
cursor_error(cursor, (*cr).next())
}
unsafe extern "C" fn rust_eof<C>(cursor: *mut ffi::sqlite3_vtab_cursor) -> c_int
where
C: VTabCursor,
{
let cr = cursor as *mut C;
(*cr).eof() as c_int
}
unsafe extern "C" fn rust_column<C>(
cursor: *mut ffi::sqlite3_vtab_cursor,
ctx: *mut ffi::sqlite3_context,
i: c_int,
) -> c_int
where
C: VTabCursor,
{
let cr = cursor as *mut C;
let mut ctxt = Context(ctx);
result_error(ctx, (*cr).column(&mut ctxt, i))
}
unsafe extern "C" fn rust_rowid<C>(
cursor: *mut ffi::sqlite3_vtab_cursor,
p_rowid: *mut ffi::sqlite3_int64,
) -> c_int
where
C: VTabCursor,
{
let cr = cursor as *mut C;
match (*cr).rowid() {
Ok(rowid) => {
*p_rowid = rowid;
ffi::SQLITE_OK
}
err => cursor_error(cursor, err),
}
}
/// Virtual table cursors can set an error message by assigning a string to
/// `zErrMsg`.
unsafe fn cursor_error<T>(cursor: *mut ffi::sqlite3_vtab_cursor, result: Result<T>) -> c_int {
use std::error::Error as StdError;
match result {
Ok(_) => ffi::SQLITE_OK,
Err(Error::SqliteFailure(err, s)) => {
if let Some(err_msg) = s {
set_err_msg((*cursor).pVtab, &err_msg);
}
err.extended_code
}
Err(err) => {
set_err_msg((*cursor).pVtab, err.description());
ffi::SQLITE_ERROR
}
}
}
/// Virtual tables methods can set an error message by assigning a string to
/// `zErrMsg`.
unsafe fn set_err_msg(vtab: *mut ffi::sqlite3_vtab, err_msg: &str) {
if !(*vtab).zErrMsg.is_null() {
ffi::sqlite3_free((*vtab).zErrMsg as *mut c_void);
}
(*vtab).zErrMsg = mprintf(err_msg);
}
/// To raise an error, the `column` method should use this method to set the
/// error message and return the error code.
unsafe fn result_error<T>(ctx: *mut ffi::sqlite3_context, result: Result<T>) -> c_int {
use std::error::Error as StdError;
match result {
Ok(_) => ffi::SQLITE_OK,
Err(Error::SqliteFailure(err, s)) => {
match err.extended_code {
ffi::SQLITE_TOOBIG => {
ffi::sqlite3_result_error_toobig(ctx);
}
ffi::SQLITE_NOMEM => {
ffi::sqlite3_result_error_nomem(ctx);
}
code => {
ffi::sqlite3_result_error_code(ctx, code);
if let Some(Ok(cstr)) = s.map(|s| str_to_cstring(&s)) {
ffi::sqlite3_result_error(ctx, cstr.as_ptr(), -1);
}
}
};
err.extended_code
}
Err(err) => {
ffi::sqlite3_result_error_code(ctx, ffi::SQLITE_ERROR);
if let Ok(cstr) = str_to_cstring(err.description()) {
ffi::sqlite3_result_error(ctx, cstr.as_ptr(), -1);
}
ffi::SQLITE_ERROR
}
}
}
// Space to hold this error message string must be obtained
// from an SQLite memory allocation function.
fn mprintf(err_msg: &str) -> *mut c_char {
let c_format = CString::new("%s").unwrap();
let c_err = CString::new(err_msg).unwrap();
unsafe { ffi::sqlite3_mprintf(c_format.as_ptr(), c_err.as_ptr()) }
}
#[cfg(feature = "array")]
pub mod array;
#[cfg(feature = "csvtab")]
pub mod csvtab;
#[cfg(feature = "bundled")]
pub mod series; // SQLite >= 3.9.0
#[cfg(test)]
mod test {
#[test]
fn test_dequote() {
assert_eq!("", super::dequote(""));
assert_eq!("'", super::dequote("'"));
assert_eq!("\"", super::dequote("\""));
assert_eq!("'\"", super::dequote("'\""));
assert_eq!("", super::dequote("''"));
assert_eq!("", super::dequote("\"\""));
assert_eq!("x", super::dequote("'x'"));
assert_eq!("x", super::dequote("\"x\""));
assert_eq!("x", super::dequote("x"));
}
#[test]
fn test_parse_boolean() {
assert_eq!(None, super::parse_boolean(""));
assert_eq!(Some(true), super::parse_boolean("1"));
assert_eq!(Some(true), super::parse_boolean("yes"));
assert_eq!(Some(true), super::parse_boolean("on"));
assert_eq!(Some(true), super::parse_boolean("true"));
assert_eq!(Some(false), super::parse_boolean("0"));
assert_eq!(Some(false), super::parse_boolean("no"));
assert_eq!(Some(false), super::parse_boolean("off"));
assert_eq!(Some(false), super::parse_boolean("false"));
}
}