sqlx-core 0.3.5

Core of SQLx, the rust SQL toolkit. Not intended to be used directly.
Documentation 
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use core::ffi::c_void;
use core::mem;

use std::os::raw::{c_char, c_int};

use libsqlite3_sys::{
    sqlite3_bind_blob, sqlite3_bind_double, sqlite3_bind_int, sqlite3_bind_int64,
    sqlite3_bind_null, sqlite3_bind_text, SQLITE_OK, SQLITE_TRANSIENT,
};

use crate::arguments::Arguments;
use crate::encode::{Encode, IsNull};
use crate::sqlite::statement::Statement;
use crate::sqlite::Sqlite;
use crate::sqlite::SqliteError;
use crate::types::Type;

#[derive(Debug, Clone)]
pub enum SqliteArgumentValue {
    Null,

    // TODO: Take by reference to remove the allocation
    Text(String),

    // TODO: Take by reference to remove the allocation
    Blob(Vec<u8>),

    Double(f64),

    Int(i32),

    Int64(i64),
}

#[derive(Default)]
pub struct SqliteArguments {
    index: usize,
    values: Vec<SqliteArgumentValue>,
}

impl SqliteArguments {
    pub(crate) fn next(&mut self) -> Option<SqliteArgumentValue> {
        if self.index >= self.values.len() {
            return None;
        }

        let mut value = SqliteArgumentValue::Null;
        mem::swap(&mut value, &mut self.values[self.index]);

        self.index += 1;
        Some(value)
    }
}

impl Arguments for SqliteArguments {
    type Database = Sqlite;

    fn reserve(&mut self, len: usize, _size_hint: usize) {
        self.values.reserve(len);
    }

    fn add<T>(&mut self, value: T)
    where
        T: Encode<Self::Database> + Type<Self::Database>,
    {
        if let IsNull::Yes = value.encode_nullable(&mut self.values) {
            self.values.push(SqliteArgumentValue::Null);
        }
    }
}

impl SqliteArgumentValue {
    pub(super) fn bind(&self, statement: &mut Statement, index: usize) -> crate::Result<()> {
        let handle = unsafe {
            if let Some(handle) = statement.handle() {
                handle
            } else {
                // drop all requested bindings for a null/empty statement
                // note that this _should_ not happen as argument size for a null statement should be zero
                return Ok(());
            }
        };

        // TODO: Handle error of trying to bind too many parameters here
        let index = index as c_int;

        // https://sqlite.org/c3ref/bind_blob.html
        let status: c_int = match self {
            SqliteArgumentValue::Blob(value) => {
                // TODO: Handle bytes that are too large
                let bytes = value.as_slice();
                let bytes_ptr = bytes.as_ptr() as *const c_void;
                let bytes_len = bytes.len() as i32;

                unsafe {
                    sqlite3_bind_blob(handle, index, bytes_ptr, bytes_len, SQLITE_TRANSIENT())
                }
            }

            SqliteArgumentValue::Text(value) => {
                // TODO: Handle text that is too large
                let bytes = value.as_bytes();
                let bytes_ptr = bytes.as_ptr() as *const c_char;
                let bytes_len = bytes.len() as i32;

                unsafe {
                    sqlite3_bind_text(handle, index, bytes_ptr, bytes_len, SQLITE_TRANSIENT())
                }
            }

            SqliteArgumentValue::Double(value) => unsafe {
                sqlite3_bind_double(handle, index, *value)
            },

            SqliteArgumentValue::Int(value) => unsafe { sqlite3_bind_int(handle, index, *value) },

            SqliteArgumentValue::Int64(value) => unsafe {
                sqlite3_bind_int64(handle, index, *value)
            },

            SqliteArgumentValue::Null => unsafe { sqlite3_bind_null(handle, index) },
        };

        if status != SQLITE_OK {
            return Err(SqliteError::from_connection(statement.connection.0.as_ptr()).into());
        }

        Ok(())
    }
}