Remove functions::FromValue.

With the new definition of FromSql, we can reuse it since we can convert
a sqlite3_value into a BorrowedValue.
This commit is contained in:
John Gallagher 2016-05-24 20:08:12 -04:00
parent 4662b9b932
commit 0fbfad2452

View File

@ -54,7 +54,6 @@ use std::ffi::CStr;
use std::mem;
use std::ptr;
use std::slice;
use std::str;
use libc::{c_int, c_double, c_char, c_void};
use ffi;
@ -63,7 +62,7 @@ pub use ffi::sqlite3_value;
pub use ffi::sqlite3_value_type;
pub use ffi::sqlite3_value_numeric_type;
use types::Null;
use types::{Null, FromSql, BorrowedValue};
use {Result, Error, Connection, str_to_cstring, InnerConnection};
@ -157,108 +156,35 @@ impl ToResult for Null {
}
}
/// A trait for types that can be created from a SQLite function parameter value.
pub trait FromValue: Sized {
unsafe fn parameter_value(v: *mut sqlite3_value) -> Result<Self>;
/// FromValue types can implement this method and use sqlite3_value_type to check that
/// the type reported by SQLite matches a type suitable for Self. This method is used
/// by `Context::get` to confirm that the parameter contains a valid type before
/// attempting to retrieve the value.
unsafe fn parameter_has_valid_sqlite_type(_: *mut sqlite3_value) -> bool {
true
}
}
macro_rules! raw_from_impl(
($t:ty, $f:ident, $c:expr) => (
impl FromValue for $t {
unsafe fn parameter_value(v: *mut sqlite3_value) -> Result<$t> {
Ok(ffi::$f(v))
}
unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
sqlite3_value_numeric_type(v) == $c
}
}
)
);
raw_from_impl!(c_int, sqlite3_value_int, ffi::SQLITE_INTEGER);
raw_from_impl!(i64, sqlite3_value_int64, ffi::SQLITE_INTEGER);
impl FromValue for bool {
unsafe fn parameter_value(v: *mut sqlite3_value) -> Result<bool> {
match ffi::sqlite3_value_int(v) {
0 => Ok(false),
_ => Ok(true),
}
}
unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
sqlite3_value_numeric_type(v) == ffi::SQLITE_INTEGER
}
}
impl FromValue for c_double {
unsafe fn parameter_value(v: *mut sqlite3_value) -> Result<c_double> {
Ok(ffi::sqlite3_value_double(v))
}
unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
sqlite3_value_numeric_type(v) == ffi::SQLITE_FLOAT ||
sqlite3_value_numeric_type(v) == ffi::SQLITE_INTEGER
}
}
impl FromValue for String {
unsafe fn parameter_value(v: *mut sqlite3_value) -> Result<String> {
let c_text = ffi::sqlite3_value_text(v);
if c_text.is_null() {
Ok("".to_owned())
} else {
let c_slice = CStr::from_ptr(c_text as *const c_char).to_bytes();
let utf8_str = try!(str::from_utf8(c_slice));
Ok(utf8_str.into())
}
}
unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
sqlite3_value_type(v) == ffi::SQLITE_TEXT
}
}
impl FromValue for Vec<u8> {
unsafe fn parameter_value(v: *mut sqlite3_value) -> Result<Vec<u8>> {
impl<'a> BorrowedValue<'a> {
unsafe fn from_value(value: *mut sqlite3_value) -> BorrowedValue<'a> {
use std::slice::from_raw_parts;
let c_blob = ffi::sqlite3_value_blob(v);
let len = ffi::sqlite3_value_bytes(v);
assert!(len >= 0,
"unexpected negative return from sqlite3_value_bytes");
let len = len as usize;
match ffi::sqlite3_value_type(value) {
ffi::SQLITE_NULL => BorrowedValue::Null,
ffi::SQLITE_INTEGER => BorrowedValue::Integer(ffi::sqlite3_value_int64(value)),
ffi::SQLITE_FLOAT => BorrowedValue::Real(ffi::sqlite3_value_double(value)),
ffi::SQLITE_TEXT => {
let text = ffi::sqlite3_value_text(value);
assert!(!text.is_null(), "unexpected SQLITE_TEXT value type with NULL data");
let s = CStr::from_ptr(text as *const c_char);
Ok(from_raw_parts(mem::transmute(c_blob), len).to_vec())
}
// sqlite3_value_text returns UTF8 data, so our unwrap here should be fine.
let s = s.to_str().expect("sqlite3_value_text returned invalid UTF-8");
BorrowedValue::Text(s)
}
ffi::SQLITE_BLOB => {
let blob = ffi::sqlite3_value_blob(value);
assert!(!blob.is_null(), "unexpected SQLITE_BLOB value type with NULL data");
unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
sqlite3_value_type(v) == ffi::SQLITE_BLOB
}
}
let len = ffi::sqlite3_value_bytes(value);
assert!(len >= 0, "unexpected negative return from sqlite3_value_bytes");
impl<T: FromValue> FromValue for Option<T> {
unsafe fn parameter_value(v: *mut sqlite3_value) -> Result<Option<T>> {
if sqlite3_value_type(v) == ffi::SQLITE_NULL {
Ok(None)
} else {
FromValue::parameter_value(v).map(Some)
BorrowedValue::Blob(from_raw_parts(blob as *const u8, len as usize))
}
_ => unreachable!("sqlite3_value_type returned invalid value")
}
}
unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
sqlite3_value_type(v) == ffi::SQLITE_NULL || T::parameter_has_valid_sqlite_type(v)
}
}
unsafe extern "C" fn free_boxed_value<T>(p: *mut c_void) {
@ -288,15 +214,13 @@ impl<'a> Context<'a> {
/// Will panic if `idx` is greater than or equal to `self.len()`.
///
/// Will return Err if the underlying SQLite type cannot be converted to a `T`.
pub fn get<T: FromValue>(&self, idx: usize) -> Result<T> {
pub fn get<T: FromSql>(&self, idx: usize) -> Result<T> {
let arg = self.args[idx];
unsafe {
if T::parameter_has_valid_sqlite_type(arg) {
T::parameter_value(arg)
} else {
Err(Error::InvalidFunctionParameterType)
}
}
let value = unsafe { BorrowedValue::from_value(arg) };
FromSql::column_result(value).map_err(|err| match err {
Error::InvalidColumnType => Error::InvalidFunctionParameterType,
_ => err
})
}
/// Sets the auxilliary data associated with a particular parameter. See