rusqlite/src/raw_statement.rs
Johnny Graettinger 7c1d5a1863 Add Statement.readonly() accessor
Remove cfg(extra_check) from RawStatement::readonly()
2023-03-23 18:55:19 +00:00

241 lines
6.8 KiB
Rust

use super::ffi;
use super::StatementStatus;
use crate::util::ParamIndexCache;
use crate::util::SqliteMallocString;
use std::ffi::CStr;
use std::os::raw::c_int;
use std::ptr;
use std::sync::Arc;
// Private newtype for raw sqlite3_stmts that finalize themselves when dropped.
#[derive(Debug)]
pub struct RawStatement {
ptr: *mut ffi::sqlite3_stmt,
tail: usize,
// Cached indices of named parameters, computed on the fly.
cache: ParamIndexCache,
// Cached SQL (trimmed) that we use as the key when we're in the statement
// cache. This is None for statements which didn't come from the statement
// cache.
//
// This is probably the same as `self.sql()` in most cases, but we don't
// care either way -- It's a better cache key as it is anyway since it's the
// actual source we got from rust.
//
// One example of a case where the result of `sqlite_sql` and the value in
// `statement_cache_key` might differ is if the statement has a `tail`.
statement_cache_key: Option<Arc<str>>,
}
impl RawStatement {
#[inline]
pub unsafe fn new(stmt: *mut ffi::sqlite3_stmt, tail: usize) -> RawStatement {
RawStatement {
ptr: stmt,
tail,
cache: ParamIndexCache::default(),
statement_cache_key: None,
}
}
#[inline]
pub fn is_null(&self) -> bool {
self.ptr.is_null()
}
#[inline]
pub(crate) fn set_statement_cache_key(&mut self, p: impl Into<Arc<str>>) {
self.statement_cache_key = Some(p.into());
}
#[inline]
pub(crate) fn statement_cache_key(&self) -> Option<Arc<str>> {
self.statement_cache_key.clone()
}
#[inline]
pub unsafe fn ptr(&self) -> *mut ffi::sqlite3_stmt {
self.ptr
}
#[inline]
pub fn column_count(&self) -> usize {
// Note: Can't cache this as it changes if the schema is altered.
unsafe { ffi::sqlite3_column_count(self.ptr) as usize }
}
#[inline]
pub fn column_type(&self, idx: usize) -> c_int {
unsafe { ffi::sqlite3_column_type(self.ptr, idx as c_int) }
}
#[inline]
#[cfg(feature = "column_decltype")]
pub fn column_decltype(&self, idx: usize) -> Option<&CStr> {
unsafe {
let decltype = ffi::sqlite3_column_decltype(self.ptr, idx as c_int);
if decltype.is_null() {
None
} else {
Some(CStr::from_ptr(decltype))
}
}
}
#[inline]
pub fn column_name(&self, idx: usize) -> Option<&CStr> {
let idx = idx as c_int;
if idx < 0 || idx >= self.column_count() as c_int {
return None;
}
unsafe {
let ptr = ffi::sqlite3_column_name(self.ptr, idx);
// If ptr is null here, it's an OOM, so there's probably nothing
// meaningful we can do. Just assert instead of returning None.
assert!(
!ptr.is_null(),
"Null pointer from sqlite3_column_name: Out of memory?"
);
Some(CStr::from_ptr(ptr))
}
}
#[inline]
#[cfg(not(feature = "unlock_notify"))]
pub fn step(&self) -> c_int {
unsafe { ffi::sqlite3_step(self.ptr) }
}
#[cfg(feature = "unlock_notify")]
pub fn step(&self) -> c_int {
use crate::unlock_notify;
let mut db = ptr::null_mut::<ffi::sqlite3>();
loop {
unsafe {
let mut rc = ffi::sqlite3_step(self.ptr);
// Bail out early for success and errors unrelated to locking. We
// still need check `is_locked` after this, but checking now lets us
// avoid one or two (admittedly cheap) calls into SQLite that we
// don't need to make.
if (rc & 0xff) != ffi::SQLITE_LOCKED {
break rc;
}
if db.is_null() {
db = ffi::sqlite3_db_handle(self.ptr);
}
if !unlock_notify::is_locked(db, rc) {
break rc;
}
rc = unlock_notify::wait_for_unlock_notify(db);
if rc != ffi::SQLITE_OK {
break rc;
}
self.reset();
}
}
}
#[inline]
pub fn reset(&self) -> c_int {
unsafe { ffi::sqlite3_reset(self.ptr) }
}
#[inline]
pub fn bind_parameter_count(&self) -> usize {
unsafe { ffi::sqlite3_bind_parameter_count(self.ptr) as usize }
}
#[inline]
pub fn bind_parameter_index(&self, name: &str) -> Option<usize> {
self.cache.get_or_insert_with(name, |param_cstr| {
let r = unsafe { ffi::sqlite3_bind_parameter_index(self.ptr, param_cstr.as_ptr()) };
match r {
0 => None,
i => Some(i as usize),
}
})
}
#[inline]
pub fn bind_parameter_name(&self, index: i32) -> Option<&CStr> {
unsafe {
let name = ffi::sqlite3_bind_parameter_name(self.ptr, index);
if name.is_null() {
None
} else {
Some(CStr::from_ptr(name))
}
}
}
#[inline]
pub fn clear_bindings(&self) {
unsafe {
ffi::sqlite3_clear_bindings(self.ptr);
} // rc is always SQLITE_OK
}
#[inline]
pub fn sql(&self) -> Option<&CStr> {
if self.ptr.is_null() {
None
} else {
Some(unsafe { CStr::from_ptr(ffi::sqlite3_sql(self.ptr)) })
}
}
#[inline]
pub fn finalize(mut self) -> c_int {
self.finalize_()
}
#[inline]
fn finalize_(&mut self) -> c_int {
let r = unsafe { ffi::sqlite3_finalize(self.ptr) };
self.ptr = ptr::null_mut();
r
}
// does not work for PRAGMA
#[inline]
pub fn readonly(&self) -> bool {
unsafe { ffi::sqlite3_stmt_readonly(self.ptr) != 0 }
}
#[inline]
pub(crate) fn expanded_sql(&self) -> Option<SqliteMallocString> {
unsafe { SqliteMallocString::from_raw(ffi::sqlite3_expanded_sql(self.ptr)) }
}
#[inline]
pub fn get_status(&self, status: StatementStatus, reset: bool) -> i32 {
assert!(!self.ptr.is_null());
unsafe { ffi::sqlite3_stmt_status(self.ptr, status as i32, reset as i32) }
}
#[inline]
#[cfg(feature = "extra_check")]
pub fn has_tail(&self) -> bool {
self.tail != 0
}
#[inline]
pub fn tail(&self) -> usize {
self.tail
}
#[inline]
#[cfg(feature = "modern_sqlite")] // 3.28.0
pub fn is_explain(&self) -> i32 {
unsafe { ffi::sqlite3_stmt_isexplain(self.ptr) }
}
// TODO sqlite3_normalized_sql (https://sqlite.org/c3ref/expanded_sql.html) // 3.27.0 + SQLITE_ENABLE_NORMALIZE
}
impl Drop for RawStatement {
fn drop(&mut self) {
self.finalize_();
}
}