use crate::{
CancelToken, Config, CopyInWriter, CopyOutReader, RowIter, Statement, ToStatement, Transaction,
TransactionBuilder,
};
use std::ops::{Deref, DerefMut};
use tokio::runtime::Runtime;
use tokio_postgres::tls::{MakeTlsConnect, TlsConnect};
use tokio_postgres::types::{ToSql, Type};
use tokio_postgres::{Error, Row, SimpleQueryMessage, Socket};
pub(crate) struct Rt<'a>(pub &'a mut Runtime);
// no-op impl to extend the borrow until drop
impl Drop for Rt<'_> {
fn drop(&mut self) {}
}
impl Deref for Rt<'_> {
type Target = Runtime;
#[inline]
fn deref(&self) -> &Runtime {
self.0
}
}
impl DerefMut for Rt<'_> {
#[inline]
fn deref_mut(&mut self) -> &mut Runtime {
self.0
}
}
/// A synchronous PostgreSQL client.
pub struct Client {
runtime: Runtime,
client: tokio_postgres::Client,
}
impl Client {
pub(crate) fn new(runtime: Runtime, client: tokio_postgres::Client) -> Client {
Client { runtime, client }
}
/// A convenience function which parses a configuration string into a `Config` and then connects to the database.
///
/// See the documentation for [`Config`] for information about the connection syntax.
///
/// [`Config`]: config/struct.Config.html
pub fn connect<T>(params: &str, tls_mode: T) -> Result<Client, Error>
where
T: MakeTlsConnect<Socket> + 'static + Send,
T::TlsConnect: Send,
T::Stream: Send,
<T::TlsConnect as TlsConnect<Socket>>::Future: Send,
{
params.parse::<Config>()?.connect(tls_mode)
}
/// Returns a new `Config` object which can be used to configure and connect to a database.
pub fn configure() -> Config {
Config::new()
}
fn rt(&mut self) -> Rt<'_> {
Rt(&mut self.runtime)
}
/// Executes a statement, returning the number of rows modified.
///
/// A statement may contain parameters, specified by `$n`, where `n` is the index of the parameter of the list
/// provided, 1-indexed.
///
/// If the statement does not modify any rows (e.g. `SELECT`), 0 is returned.
///
/// The `query` argument can either be a `Statement`, or a raw query string. If the same statement will be
/// repeatedly executed (perhaps with different query parameters), consider preparing the statement up front
/// with the `prepare` method.
///
/// # Panics
///
/// Panics if the number of parameters provided does not match the number expected.
///
/// # Example
///
/// ```no_run
/// use postgres::{Client, NoTls};
///
/// # fn main() -> Result<(), postgres::Error> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let bar = 1i32;
/// let baz = true;
/// let rows_updated = client.execute(
/// "UPDATE foo SET bar = $1 WHERE baz = $2",
/// &[&bar, &baz],
/// )?;
///
/// println!("{} rows updated", rows_updated);
/// # Ok(())
/// # }
/// ```
pub fn execute<T>(&mut self, query: &T, params: &[&(dyn ToSql + Sync)]) -> Result<u64, Error>
where
T: ?Sized + ToStatement,
{
self.runtime.block_on(self.client.execute(query, params))
}
/// Executes a statement, returning the resulting rows.
///
/// A statement may contain parameters, specified by `$n`, where `n` is the index of the parameter of the list
/// provided, 1-indexed.
///
/// The `query` argument can either be a `Statement`, or a raw query string. If the same statement will be
/// repeatedly executed (perhaps with different query parameters), consider preparing the statement up front
/// with the `prepare` method.
///
/// # Panics
///
/// Panics if the number of parameters provided does not match the number expected.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
///
/// # fn main() -> Result<(), postgres::Error> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let baz = true;
/// for row in client.query("SELECT foo FROM bar WHERE baz = $1", &[&baz])? {
/// let foo: i32 = row.get("foo");
/// println!("foo: {}", foo);
/// }
/// # Ok(())
/// # }
/// ```
pub fn query<T>(&mut self, query: &T, params: &[&(dyn ToSql + Sync)]) -> Result<Vec<Row>, Error>
where
T: ?Sized + ToStatement,
{
self.runtime.block_on(self.client.query(query, params))
}
/// Executes a statement which returns a single row, returning it.
///
/// Returns an error if the query does not return exactly one row.
///
/// A statement may contain parameters, specified by `$n`, where `n` is the index of the parameter of the list
/// provided, 1-indexed.
///
/// The `query` argument can either be a `Statement`, or a raw query string. If the same statement will be
/// repeatedly executed (perhaps with different query parameters), consider preparing the statement up front
/// with the `prepare` method.
///
/// # Panics
///
/// Panics if the number of parameters provided does not match the number expected.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
///
/// # fn main() -> Result<(), postgres::Error> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let baz = true;
/// let row = client.query_one("SELECT foo FROM bar WHERE baz = $1", &[&baz])?;
/// let foo: i32 = row.get("foo");
/// println!("foo: {}", foo);
/// # Ok(())
/// # }
/// ```
pub fn query_one<T>(&mut self, query: &T, params: &[&(dyn ToSql + Sync)]) -> Result<Row, Error>
where
T: ?Sized + ToStatement,
{
self.runtime.block_on(self.client.query_one(query, params))
}
/// Executes a statement which returns zero or one rows, returning it.
///
/// Returns an error if the query returns more than one row.
///
/// A statement may contain parameters, specified by `$n`, where `n` is the index of the parameter of the list
/// provided, 1-indexed.
///
/// The `query` argument can either be a `Statement`, or a raw query string. If the same statement will be
/// repeatedly executed (perhaps with different query parameters), consider preparing the statement up front
/// with the `prepare` method.
///
/// # Panics
///
/// Panics if the number of parameters provided does not match the number expected.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
///
/// # fn main() -> Result<(), postgres::Error> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let baz = true;
/// let row = client.query_opt("SELECT foo FROM bar WHERE baz = $1", &[&baz])?;
/// match row {
/// Some(row) => {
/// let foo: i32 = row.get("foo");
/// println!("foo: {}", foo);
/// }
/// None => println!("no matching foo"),
/// }
/// # Ok(())
/// # }
/// ```
pub fn query_opt<T>(
&mut self,
query: &T,
params: &[&(dyn ToSql + Sync)],
) -> Result<Option<Row>, Error>
where
T: ?Sized + ToStatement,
{
self.runtime.block_on(self.client.query_opt(query, params))
}
/// A maximally-flexible version of `query`.
///
/// It takes an iterator of parameters rather than a slice, and returns an iterator of rows rather than collecting
/// them into an array.
///
/// # Panics
///
/// Panics if the number of parameters provided does not match the number expected.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
/// use fallible_iterator::FallibleIterator;
/// use std::iter;
///
/// # fn main() -> Result<(), postgres::Error> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let baz = true;
/// let mut it = client.query_raw("SELECT foo FROM bar WHERE baz = $1", iter::once(&baz as _))?;
///
/// while let Some(row) = it.next()? {
/// let foo: i32 = row.get("foo");
/// println!("foo: {}", foo);
/// }
/// # Ok(())
/// # }
/// ```
pub fn query_raw<'a, T, I>(&mut self, query: &T, params: I) -> Result<RowIter<'_>, Error>
where
T: ?Sized + ToStatement,
I: IntoIterator<Item = &'a dyn ToSql>,
I::IntoIter: ExactSizeIterator,
{
let stream = self
.runtime
.block_on(self.client.query_raw(query, params))?;
Ok(RowIter::new(self.rt(), stream))
}
/// Creates a new prepared statement.
///
/// Prepared statements can be executed repeatedly, and may contain query parameters (indicated by `$1`, `$2`, etc),
/// which are set when executed. Prepared statements can only be used with the connection that created them.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
///
/// # fn main() -> Result<(), postgres::Error> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let statement = client.prepare("SELECT name FROM people WHERE id = $1")?;
///
/// for id in 0..10 {
/// let rows = client.query(&statement, &[&id])?;
/// let name: &str = rows[0].get(0);
/// println!("name: {}", name);
/// }
/// # Ok(())
/// # }
/// ```
pub fn prepare(&mut self, query: &str) -> Result<Statement, Error> {
self.runtime.block_on(self.client.prepare(query))
}
/// Like `prepare`, but allows the types of query parameters to be explicitly specified.
///
/// The list of types may be smaller than the number of parameters - the types of the remaining parameters will be
/// inferred. For example, `client.prepare_typed(query, &[])` is equivalent to `client.prepare(query)`.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
/// use postgres::types::Type;
///
/// # fn main() -> Result<(), postgres::Error> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let statement = client.prepare_typed(
/// "SELECT name FROM people WHERE id = $1",
/// &[Type::INT8],
/// )?;
///
/// for id in 0..10 {
/// let rows = client.query(&statement, &[&id])?;
/// let name: &str = rows[0].get(0);
/// println!("name: {}", name);
/// }
/// # Ok(())
/// # }
/// ```
pub fn prepare_typed(&mut self, query: &str, types: &[Type]) -> Result<Statement, Error> {
self.runtime
.block_on(self.client.prepare_typed(query, types))
}
/// Executes a `COPY FROM STDIN` statement, returning the number of rows created.
///
/// The `query` argument can either be a `Statement`, or a raw query string. The data in the provided reader is
/// passed along to the server verbatim; it is the caller's responsibility to ensure it uses the proper format.
/// PostgreSQL does not support parameters in `COPY` statements, so this method does not take any.
///
/// The copy *must* be explicitly completed via the `finish` method. If it is not, the copy will be aborted.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
/// use std::io::Write;
///
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let mut writer = client.copy_in("COPY people FROM stdin")?;
/// writer.write_all(b"1\tjohn\n2\tjane\n")?;
/// writer.finish()?;
/// # Ok(())
/// # }
/// ```
pub fn copy_in<T>(&mut self, query: &T) -> Result<CopyInWriter<'_>, Error>
where
T: ?Sized + ToStatement,
{
let sink = self.runtime.block_on(self.client.copy_in(query))?;
Ok(CopyInWriter::new(self.rt(), sink))
}
/// Executes a `COPY TO STDOUT` statement, returning a reader of the resulting data.
///
/// The `query` argument can either be a `Statement`, or a raw query string. PostgreSQL does not support parameters
/// in `COPY` statements, so this method does not take any.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
/// use std::io::Read;
///
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let mut reader = client.copy_out("COPY people TO stdout")?;
/// let mut buf = vec![];
/// reader.read_to_end(&mut buf)?;
/// # Ok(())
/// # }
/// ```
pub fn copy_out<T>(&mut self, query: &T) -> Result<CopyOutReader<'_>, Error>
where
T: ?Sized + ToStatement,
{
let stream = self.runtime.block_on(self.client.copy_out(query))?;
Ok(CopyOutReader::new(self.rt(), stream))
}
/// Executes a sequence of SQL statements using the simple query protocol.
///
/// Statements should be separated by semicolons. If an error occurs, execution of the sequence will stop at that
/// point. The simple query protocol returns the values in rows as strings rather than in their binary encodings,
/// so the associated row type doesn't work with the `FromSql` trait. Rather than simply returning the rows, this
/// method returns a sequence of an enum which indicates either the completion of one of the commands, or a row of
/// data. This preserves the framing between the separate statements in the request.
///
/// This is a simple convenience method over `simple_query_iter`.
///
/// # Warning
///
/// Prepared statements should be use for any query which contains user-specified data, as they provided the
/// functionality to safely imbed that data in the request. Do not form statements via string concatenation and pass
/// them to this method!
pub fn simple_query(&mut self, query: &str) -> Result<Vec<SimpleQueryMessage>, Error> {
self.runtime.block_on(self.client.simple_query(query))
}
/// Executes a sequence of SQL statements using the simple query protocol.
///
/// Statements should be separated by semicolons. If an error occurs, execution of the sequence will stop at that
/// point. This is intended for use when, for example, initializing a database schema.
///
/// # Warning
///
/// Prepared statements should be use for any query which contains user-specified data, as they provided the
/// functionality to safely embed that data in the request. Do not form statements via string concatenation and pass
/// them to this method!
pub fn batch_execute(&mut self, query: &str) -> Result<(), Error> {
self.runtime.block_on(self.client.batch_execute(query))
}
/// Begins a new database transaction.
///
/// The transaction will roll back by default - use the `commit` method to commit it.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
///
/// # fn main() -> Result<(), postgres::Error> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let mut transaction = client.transaction()?;
/// transaction.execute("UPDATE foo SET bar = 10", &[])?;
/// // ...
///
/// transaction.commit()?;
/// # Ok(())
/// # }
/// ```
pub fn transaction(&mut self) -> Result<Transaction<'_>, Error> {
let transaction = self.runtime.block_on(self.client.transaction())?;
Ok(Transaction::new(&mut self.runtime, transaction))
}
/// Returns a builder for a transaction with custom settings.
///
/// Unlike the `transaction` method, the builder can be used to control the transaction's isolation level and other
/// attributes.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, IsolationLevel, NoTls};
///
/// # fn main() -> Result<(), postgres::Error> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let mut transaction = client.build_transaction()
/// .isolation_level(IsolationLevel::RepeatableRead)
/// .start()?;
/// transaction.execute("UPDATE foo SET bar = 10", &[])?;
/// // ...
///
/// transaction.commit()?;
/// # Ok(())
/// # }
/// ```
pub fn build_transaction(&mut self) -> TransactionBuilder<'_> {
TransactionBuilder::new(&mut self.runtime, self.client.build_transaction())
}
/// Constructs a cancellation token that can later be used to request
/// cancellation of a query running on this connection.
///
/// # Examples
///
/// ```no_run
/// use postgres::{Client, NoTls};
/// use postgres::error::SqlState;
/// use std::thread;
/// use std::time::Duration;
///
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let mut client = Client::connect("host=localhost user=postgres", NoTls)?;
///
/// let cancel_token = client.cancel_token();
///
/// thread::spawn(move || {
/// // Abort the query after 5s.
/// thread::sleep(Duration::from_secs(5));
/// cancel_token.cancel_query(NoTls);
/// });
///
/// match client.simple_query("SELECT long_running_query()") {
/// Err(e) if e.code() == Some(&SqlState::QUERY_CANCELED) => {
/// // Handle canceled query.
/// }
/// Err(err) => return Err(err.into()),
/// Ok(rows) => {
/// // ...
/// }
/// }
/// // ...
///
/// # Ok(())
/// # }
/// ```
pub fn cancel_token(&self) -> CancelToken {
CancelToken::new(self.client.cancel_token())
}
/// Determines if the client's connection has already closed.
///
/// If this returns `true`, the client is no longer usable.
pub fn is_closed(&self) -> bool {
self.client.is_closed()
}
}