1227 lines
37 KiB
Rust
1227 lines
37 KiB
Rust
/*!
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Rust-Postgres is a pure-Rust frontend for the popular PostgreSQL database. It
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exposes a high level interface in the vein of JDBC or Go's `database/sql`
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package.
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```rust
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extern mod postgres = "github.com/sfackler/rust-postgres";
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extern mod extra;
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use extra::time;
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use extra::time::Timespec;
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use postgres::{PostgresConnection, PostgresStatement, NoSsl};
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use postgres::types::ToSql;
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struct Person {
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id: i32,
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name: ~str,
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time_created: Timespec,
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data: Option<~[u8]>
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}
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fn main() {
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let conn = PostgresConnection::connect("postgres://postgres@localhost",
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&NoSsl);
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conn.update("CREATE TABLE person (
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id SERIAL PRIMARY KEY,
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name VARCHAR NOT NULL,
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time_created TIMESTAMP NOT NULL,
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data BYTEA
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)", []);
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let me = Person {
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id: 0,
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name: ~"Steven",
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time_created: time::get_time(),
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data: None
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};
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conn.update("INSERT INTO person (name, time_created, data)
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VALUES ($1, $2, $3)",
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[&me.name as &ToSql, &me.time_created as &ToSql,
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&me.data as &ToSql]);
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let stmt = conn.prepare("SELECT id, name, time_created, data FROM person");
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for row in stmt.query([]) {
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let person = Person {
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id: row[1],
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name: row[2],
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time_created: row[3],
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data: row[4]
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};
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println!("Found person {}", person.name);
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}
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}
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```
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*/
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#[desc="A native PostgreSQL driver"];
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#[license="MIT"];
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// Needed for rustdoc-ng
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#[link(name="rust-postgres", vers="0.1",
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package_id="github.com/sfackler/rust-postgres")];
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#[doc(html_root_url="http://sfackler.com/doc/rust-postgres/")];
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#[warn(missing_doc)];
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#[feature(macro_rules, struct_variant, globs)];
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extern mod extra;
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extern mod ssl = "github.com/sfackler/rust-ssl";
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use extra::container::Deque;
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use extra::ringbuf::RingBuf;
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use extra::url::{UserInfo, Url};
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use ssl::{SslStream, SslContext};
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use std::cell::RefCell;
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use std::io::io_error;
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use std::io::buffered::BufferedStream;
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use std::io::net;
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use std::io::net::ip::{Port, SocketAddr};
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use std::io::net::tcp::TcpStream;
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use std::task;
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use std::str;
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use self::error::{PostgresDbError,
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PostgresConnectError,
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InvalidUrl,
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DnsError,
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SocketError,
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NoSslSupport,
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SslError,
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MissingUser,
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DbError,
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UnsupportedAuthentication,
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MissingPassword};
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use self::message::{BackendMessage,
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AuthenticationOk,
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AuthenticationKerberosV5,
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AuthenticationCleartextPassword,
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AuthenticationMD5Password,
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AuthenticationSCMCredential,
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AuthenticationGSS,
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AuthenticationSSPI,
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BackendKeyData,
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BindComplete,
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CommandComplete,
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DataRow,
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EmptyQueryResponse,
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ErrorResponse,
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NoData,
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NoticeResponse,
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NotificationResponse,
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ParameterDescription,
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ParameterStatus,
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ParseComplete,
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PortalSuspended,
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ReadyForQuery,
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RowDescription};
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use self::message::{FrontendMessage,
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Bind,
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CancelRequest,
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Close,
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Describe,
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Execute,
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Parse,
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PasswordMessage,
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Query,
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StartupMessage,
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SslRequest,
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Sync,
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Terminate};
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use self::message::{RowDescriptionEntry, WriteMessage, ReadMessage};
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use self::types::{PostgresType, ToSql, FromSql};
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use self::util::digest::Digest;
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use self::util::md5::Md5;
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pub mod error;
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pub mod pool;
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mod message;
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pub mod types;
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mod util;
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static DEFAULT_PORT: Port = 5432;
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/// Trait for types that can handle Postgres notice messages
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pub trait PostgresNoticeHandler {
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/// Handle a Postgres notice message
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fn handle(&mut self, notice: PostgresDbError);
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}
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/// A notice handler which logs at the `info` level.
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///
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/// This is the default handler used by a `PostgresConnection`.
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pub struct DefaultNoticeHandler;
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impl PostgresNoticeHandler for DefaultNoticeHandler {
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fn handle(&mut self, notice: PostgresDbError) {
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info!("{}: {}", notice.severity, notice.message);
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}
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}
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/// An asynchronous notification
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pub struct PostgresNotification {
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/// The process ID of the notifying backend process
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pid: i32,
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/// The name of the channel that the notify has been raised on
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channel: ~str,
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/// The "payload" string passed from the notifying process
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payload: ~str,
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}
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/// An iterator over asynchronous notifications
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pub struct PostgresNotificationIterator<'conn> {
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priv conn: &'conn PostgresConnection
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}
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impl<'conn > Iterator<PostgresNotification> for
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PostgresNotificationIterator<'conn> {
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/// Returns the oldest pending notification or `None` if there are none.
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///
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/// # Note
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///
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/// `next` may return `Some` notification after returning `None` if a new
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/// notification was received.
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fn next(&mut self) -> Option<PostgresNotification> {
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self.conn.conn.with_mut(|conn| { conn.notifications.pop_front() })
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}
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}
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/// Contains information necessary to cancel queries for a session
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pub struct PostgresCancelData {
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/// The process ID of the session
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process_id: i32,
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/// The secret key for the session
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secret_key: i32,
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}
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/// Attempts to cancel an in-progress query.
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///
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/// The backend provides no information about whether a cancellation attempt
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/// was successful or not. An error will only be returned if the driver was
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/// unable to connect to the database.
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///
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/// A `PostgresCancelData` object can be created via
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/// `PostgresConnection::cancel_data`. The object can cancel any query made on
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/// that connection.
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pub fn cancel_query(url: &str, ssl: &SslMode, data: PostgresCancelData)
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-> Option<PostgresConnectError> {
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let Url { host, port, .. }: Url = match FromStr::from_str(url) {
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Some(url) => url,
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None => return Some(InvalidUrl)
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};
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let port = match port {
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Some(port) => FromStr::from_str(port).unwrap(),
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None => DEFAULT_PORT
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};
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let mut socket = match initialize_stream(host, port, ssl) {
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Ok(socket) => socket,
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Err(err) => return Some(err)
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};
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socket.write_message(&CancelRequest {
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code: message::CANCEL_CODE,
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process_id: data.process_id,
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secret_key: data.secret_key
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});
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socket.flush();
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None
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}
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fn open_socket(host: &str, port: Port)
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-> Result<TcpStream, PostgresConnectError> {
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let addrs = io_error::cond.trap(|_| {}).inside(|| {
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net::get_host_addresses(host)
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});
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let addrs = match addrs {
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Some(addrs) => addrs,
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None => return Err(DnsError)
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};
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for addr in addrs.iter() {
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let socket = io_error::cond.trap(|_| {}).inside(|| {
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TcpStream::connect(SocketAddr { ip: *addr, port: port })
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});
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match socket {
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Some(socket) => return Ok(socket),
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None => {}
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}
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}
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Err(SocketError)
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}
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fn initialize_stream(host: &str, port: Port, ssl: &SslMode)
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-> Result<InternalStream, PostgresConnectError> {
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let mut socket = match open_socket(host, port) {
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Ok(socket) => socket,
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Err(err) => return Err(err)
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};
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let (ssl_required, ctx) = match ssl {
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&NoSsl => return Ok(Normal(socket)),
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&PreferSsl(ref ctx) => (false, ctx),
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&RequireSsl(ref ctx) => (true, ctx)
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};
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socket.write_message(&SslRequest { code: message::SSL_CODE });
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socket.flush();
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if socket.read_u8() == 'N' as u8 {
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if ssl_required {
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return Err(NoSslSupport);
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} else {
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return Ok(Normal(socket));
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}
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}
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match SslStream::try_new(ctx, socket) {
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Ok(stream) => Ok(Ssl(stream)),
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Err(err) => Err(SslError(err))
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}
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}
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enum InternalStream {
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Normal(TcpStream),
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Ssl(SslStream<TcpStream>)
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}
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impl Reader for InternalStream {
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fn read(&mut self, buf: &mut [u8]) -> Option<uint> {
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match *self {
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Normal(ref mut s) => s.read(buf),
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Ssl(ref mut s) => s.read(buf)
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}
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}
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fn eof(&mut self) -> bool {
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match *self {
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Normal(ref mut s) => s.eof(),
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Ssl(ref mut s) => s.eof()
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}
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}
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}
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impl Writer for InternalStream {
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fn write(&mut self, buf: &[u8]) {
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match *self {
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Normal(ref mut s) => s.write(buf),
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Ssl(ref mut s) => s.write(buf)
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}
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}
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}
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struct InnerPostgresConnection {
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stream: BufferedStream<InternalStream>,
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next_stmt_id: int,
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notice_handler: ~PostgresNoticeHandler,
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notifications: RingBuf<PostgresNotification>,
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cancel_data: PostgresCancelData
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}
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impl Drop for InnerPostgresConnection {
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fn drop(&mut self) {
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io_error::cond.trap(|_| {}).inside(|| {
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self.write_messages([Terminate]);
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})
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}
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}
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impl InnerPostgresConnection {
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fn try_connect(url: &str, ssl: &SslMode)
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-> Result<InnerPostgresConnection, PostgresConnectError> {
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let Url {
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host,
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port,
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user,
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path,
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query: mut args,
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..
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}: Url = match FromStr::from_str(url) {
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Some(url) => url,
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None => return Err(InvalidUrl)
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};
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let user = match user {
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Some(user) => user,
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None => return Err(MissingUser)
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};
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let port = match port {
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Some(port) => FromStr::from_str(port).unwrap(),
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None => DEFAULT_PORT
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};
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let stream = match initialize_stream(host, port, ssl) {
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Ok(stream) => stream,
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Err(err) => return Err(err)
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};
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let mut conn = InnerPostgresConnection {
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stream: BufferedStream::new(stream),
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next_stmt_id: 0,
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notice_handler: ~DefaultNoticeHandler as ~PostgresNoticeHandler,
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notifications: RingBuf::new(),
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cancel_data: PostgresCancelData { process_id: 0, secret_key: 0 }
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};
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args.push((~"client_encoding", ~"UTF8"));
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// Postgres uses the value of TimeZone as the time zone for TIMESTAMP
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// WITH TIME ZONE values. Timespec converts to GMT internally.
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args.push((~"TimeZone", ~"GMT"));
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// We have to clone here since we need the user again for auth
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args.push((~"user", user.user.clone()));
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if !path.is_empty() {
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// path contains the leading /
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args.push((~"database", path.slice_from(1).to_owned()));
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}
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conn.write_messages([StartupMessage {
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version: message::PROTOCOL_VERSION,
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parameters: args.as_slice()
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}]);
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match conn.handle_auth(user) {
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Some(err) => return Err(err),
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None => {}
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}
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loop {
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match conn.read_message() {
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BackendKeyData { process_id, secret_key } => {
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conn.cancel_data.process_id = process_id;
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conn.cancel_data.secret_key = secret_key;
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}
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ReadyForQuery { .. } => break,
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ErrorResponse { fields } =>
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return Err(DbError(PostgresDbError::new(fields))),
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_ => unreachable!()
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}
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}
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Ok(conn)
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}
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fn write_messages(&mut self, messages: &[FrontendMessage]) {
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for message in messages.iter() {
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self.stream.write_message(message);
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}
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self.stream.flush();
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}
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fn read_message(&mut self) -> BackendMessage {
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loop {
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match self.stream.read_message() {
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NoticeResponse { fields } =>
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self.notice_handler.handle(PostgresDbError::new(fields)),
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NotificationResponse { pid, channel, payload } =>
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self.notifications.push_back(PostgresNotification {
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pid: pid,
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channel: channel,
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payload: payload
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}),
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ParameterStatus { parameter, value } =>
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info!("Parameter {} = {}", parameter, value),
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msg => return msg
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}
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}
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}
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fn handle_auth(&mut self, user: UserInfo) -> Option<PostgresConnectError> {
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match self.read_message() {
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AuthenticationOk => return None,
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AuthenticationCleartextPassword => {
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let pass = match user.pass {
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Some(pass) => pass,
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None => return Some(MissingPassword)
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};
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self.write_messages([PasswordMessage { password: pass }]);
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}
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AuthenticationMD5Password { salt } => {
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let UserInfo { user, pass } = user;
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let pass = match pass {
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Some(pass) => pass,
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None => return Some(MissingPassword)
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};
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let input = pass + user;
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let mut md5 = Md5::new();
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md5.input_str(input);
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let output = md5.result_str();
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md5.reset();
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md5.input_str(output);
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md5.input(salt);
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let output = "md5" + md5.result_str();
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self.write_messages([PasswordMessage {
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password: output.as_slice()
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}]);
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}
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AuthenticationKerberosV5
|
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| AuthenticationSCMCredential
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| AuthenticationGSS
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| AuthenticationSSPI => return Some(UnsupportedAuthentication),
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ErrorResponse { fields } =>
|
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return Some(DbError(PostgresDbError::new(fields))),
|
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_ => unreachable!()
|
|
}
|
|
|
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match self.read_message() {
|
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AuthenticationOk => None,
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|
ErrorResponse { fields } =>
|
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Some(DbError(PostgresDbError::new(fields))),
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_ => unreachable!()
|
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}
|
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}
|
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|
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fn set_notice_handler(&mut self, handler: ~PostgresNoticeHandler)
|
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-> ~PostgresNoticeHandler {
|
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::std::util::replace(&mut self.notice_handler, handler)
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}
|
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|
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fn try_prepare<'a>(&mut self, query: &str, conn: &'a PostgresConnection)
|
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-> Result<NormalPostgresStatement<'a>, PostgresDbError> {
|
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let stmt_name = format!("statement_{}", self.next_stmt_id);
|
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self.next_stmt_id += 1;
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|
|
let types = [];
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self.write_messages([
|
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Parse {
|
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name: stmt_name,
|
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query: query,
|
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param_types: types
|
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},
|
|
Describe {
|
|
variant: 'S' as u8,
|
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name: stmt_name
|
|
},
|
|
Sync]);
|
|
|
|
match self.read_message() {
|
|
ParseComplete => {}
|
|
ErrorResponse { fields } => {
|
|
self.wait_for_ready();
|
|
return Err(PostgresDbError::new(fields));
|
|
}
|
|
_ => unreachable!()
|
|
}
|
|
|
|
let param_types = match self.read_message() {
|
|
ParameterDescription { types } =>
|
|
types.iter().map(|ty| { PostgresType::from_oid(*ty) })
|
|
.collect(),
|
|
_ => unreachable!()
|
|
};
|
|
|
|
let result_desc = match self.read_message() {
|
|
RowDescription { descriptions } =>
|
|
descriptions.move_iter().map(|desc| {
|
|
ResultDescription::from_row_description_entry(desc)
|
|
}).collect(),
|
|
NoData => ~[],
|
|
_ => unreachable!()
|
|
};
|
|
|
|
self.wait_for_ready();
|
|
|
|
Ok(NormalPostgresStatement {
|
|
conn: conn,
|
|
name: stmt_name,
|
|
param_types: param_types,
|
|
result_desc: result_desc,
|
|
next_portal_id: RefCell::new(0)
|
|
})
|
|
}
|
|
|
|
fn wait_for_ready(&mut self) {
|
|
match self.read_message() {
|
|
ReadyForQuery { .. } => {}
|
|
_ => unreachable!()
|
|
}
|
|
}
|
|
|
|
fn quick_query(&mut self, query: &str) -> ~[~[Option<~str>]] {
|
|
self.write_messages([Query { query: query }]);
|
|
|
|
let mut result = ~[];
|
|
loop {
|
|
match self.read_message() {
|
|
ReadyForQuery { .. } => break,
|
|
DataRow { row } =>
|
|
result.push(row.move_iter().map(|opt|
|
|
opt.map(|b| str::from_utf8_owned(b))).collect()),
|
|
ErrorResponse { fields } =>
|
|
fail!("Error: {}",
|
|
PostgresDbError::new(fields).to_str()),
|
|
_ => {}
|
|
}
|
|
}
|
|
result
|
|
}
|
|
}
|
|
|
|
/// A connection to a Postgres database.
|
|
pub struct PostgresConnection {
|
|
priv conn: RefCell<InnerPostgresConnection>
|
|
}
|
|
|
|
impl PostgresConnection {
|
|
/// Attempts to create a new connection to a Postgres database.
|
|
///
|
|
/// The URL should be provided in the normal format:
|
|
///
|
|
/// ```
|
|
/// postgres://user[:password]@host[:port][/database][?param1=val1[[¶m2=val2]...]]
|
|
/// ```
|
|
///
|
|
/// The password may be omitted if not required. The default Postgres port
|
|
/// (5432) is used if none is specified. The database name defaults to the
|
|
/// username if not specified.
|
|
pub fn try_connect(url: &str, ssl: &SslMode)
|
|
-> Result<PostgresConnection, PostgresConnectError> {
|
|
InnerPostgresConnection::try_connect(url, ssl).map(|conn| {
|
|
PostgresConnection {
|
|
conn: RefCell::new(conn)
|
|
}
|
|
})
|
|
}
|
|
|
|
/// A convenience wrapper around `try_connect`.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if there was an error connecting to the database.
|
|
pub fn connect(url: &str, ssl: &SslMode) -> PostgresConnection {
|
|
match PostgresConnection::try_connect(url, ssl) {
|
|
Ok(conn) => conn,
|
|
Err(err) => fail!("Failed to connect: {}", err.to_str())
|
|
}
|
|
}
|
|
|
|
/// Sets the notice handler for the connection, returning the old handler.
|
|
pub fn set_notice_handler(&self, handler: ~PostgresNoticeHandler)
|
|
-> ~PostgresNoticeHandler {
|
|
let mut conn = self.conn.borrow_mut();
|
|
conn.get().set_notice_handler(handler)
|
|
}
|
|
|
|
/// Returns an iterator over asynchronous notification messages.
|
|
///
|
|
/// Use the `LISTEN` command to register this connection for notifications.
|
|
pub fn notifications<'a>(&'a self) -> PostgresNotificationIterator<'a> {
|
|
PostgresNotificationIterator {
|
|
conn: self
|
|
}
|
|
}
|
|
|
|
/// Attempts to create a new prepared statement.
|
|
///
|
|
/// A statement may contain parameters, specified by `$n` where `n` is the
|
|
/// index of the parameter in the list provided at execution time,
|
|
/// 1-indexed.
|
|
///
|
|
/// The statement is associated with the connection that created it and may
|
|
/// not outlive that connection.
|
|
pub fn try_prepare<'a>(&'a self, query: &str)
|
|
-> Result<NormalPostgresStatement<'a>, PostgresDbError> {
|
|
self.conn.with_mut(|conn| conn.try_prepare(query, self))
|
|
}
|
|
|
|
/// A convenience wrapper around `try_prepare`.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if there was an error preparing the statement.
|
|
pub fn prepare<'a>(&'a self, query: &str) -> NormalPostgresStatement<'a> {
|
|
match self.try_prepare(query) {
|
|
Ok(stmt) => stmt,
|
|
Err(err) => fail!("Error preparing statement:\n{}",
|
|
err.pretty_error(query))
|
|
}
|
|
}
|
|
|
|
/// Begins a new transaction.
|
|
///
|
|
/// Returns a `PostgresTransaction` object which should be used instead of
|
|
/// the connection for the duration of the transaction. The transaction
|
|
/// is active until the `PostgresTransaction` object falls out of scope.
|
|
/// A transaction will commit by default unless the task fails or the
|
|
/// transaction is set to roll back.
|
|
pub fn transaction<'a>(&'a self) -> PostgresTransaction<'a> {
|
|
self.quick_query("BEGIN");
|
|
PostgresTransaction {
|
|
conn: self,
|
|
commit: RefCell::new(true),
|
|
nested: false
|
|
}
|
|
}
|
|
|
|
/// A convenience function for update queries that are only run once.
|
|
///
|
|
/// If an error is returned, it could have come from either the preparation
|
|
/// or execution of the statement.
|
|
///
|
|
/// On success, returns the number of rows modified or 0 if not applicable.
|
|
pub fn try_update(&self, query: &str, params: &[&ToSql])
|
|
-> Result<uint, PostgresDbError> {
|
|
self.try_prepare(query).and_then(|stmt| stmt.try_update(params))
|
|
}
|
|
|
|
/// A convenience wrapper around `try_update`.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if there was an error preparing or executing the statement.
|
|
pub fn update(&self, query: &str, params: &[&ToSql]) -> uint {
|
|
match self.try_update(query, params) {
|
|
Ok(res) => res,
|
|
Err(err) => fail!("Error running update:\n{}",
|
|
err.pretty_error(query))
|
|
}
|
|
}
|
|
|
|
/// Returns information used to cancel pending queries.
|
|
///
|
|
/// Used with the `cancel_query` function. The object returned can be used
|
|
/// to cancel any query executed by the connection it was created from.
|
|
pub fn cancel_data(&self) -> PostgresCancelData {
|
|
self.conn.with(|conn| conn.cancel_data)
|
|
}
|
|
|
|
fn quick_query(&self, query: &str) -> ~[~[Option<~str>]] {
|
|
self.conn.with_mut(|conn| conn.quick_query(query))
|
|
}
|
|
|
|
fn wait_for_ready(&self) {
|
|
self.conn.with_mut(|conn| conn.wait_for_ready())
|
|
}
|
|
|
|
fn read_message(&self) -> BackendMessage {
|
|
self.conn.with_mut(|conn| conn.read_message())
|
|
}
|
|
|
|
fn write_messages(&self, messages: &[FrontendMessage]) {
|
|
self.conn.with_mut(|conn| conn.write_messages(messages))
|
|
}
|
|
}
|
|
|
|
/// Specifies the SSL support requested for a new connection
|
|
pub enum SslMode {
|
|
/// The connection will not use SSL
|
|
NoSsl,
|
|
/// The connection will use SSL if the backend supports it
|
|
PreferSsl(SslContext),
|
|
/// The connection must use SSL
|
|
RequireSsl(SslContext)
|
|
}
|
|
|
|
/// Represents a transaction on a database connection
|
|
pub struct PostgresTransaction<'conn> {
|
|
priv conn: &'conn PostgresConnection,
|
|
priv commit: RefCell<bool>,
|
|
priv nested: bool
|
|
}
|
|
|
|
#[unsafe_destructor]
|
|
impl<'conn> Drop for PostgresTransaction<'conn> {
|
|
fn drop(&mut self) {
|
|
io_error::cond.trap(|_| {}).inside(|| {
|
|
if task::failing() || !self.commit.with(|x| *x) {
|
|
if self.nested {
|
|
self.conn.quick_query("ROLLBACK TO sp");
|
|
} else {
|
|
self.conn.quick_query("ROLLBACK");
|
|
}
|
|
} else {
|
|
if self.nested {
|
|
self.conn.quick_query("RELEASE sp");
|
|
} else {
|
|
self.conn.quick_query("COMMIT");
|
|
}
|
|
}
|
|
})
|
|
}
|
|
}
|
|
|
|
impl<'conn> PostgresTransaction<'conn> {
|
|
/// Like `PostgresConnection::try_prepare`.
|
|
pub fn try_prepare<'a>(&'a self, query: &str)
|
|
-> Result<TransactionalPostgresStatement<'a>, PostgresDbError> {
|
|
self.conn.try_prepare(query).map(|stmt| {
|
|
TransactionalPostgresStatement {
|
|
stmt: stmt
|
|
}
|
|
})
|
|
}
|
|
|
|
/// Like `PostgresConnection::prepare`.
|
|
pub fn prepare<'a>(&'a self, query: &str)
|
|
-> TransactionalPostgresStatement<'a> {
|
|
TransactionalPostgresStatement {
|
|
stmt: self.conn.prepare(query)
|
|
}
|
|
}
|
|
|
|
/// Like `PostgresConnection::try_update`.
|
|
pub fn try_update(&self, query: &str, params: &[&ToSql])
|
|
-> Result<uint, PostgresDbError> {
|
|
self.conn.try_update(query, params)
|
|
}
|
|
|
|
/// Like `PostgresConnection::update`.
|
|
pub fn update(&self, query: &str, params: &[&ToSql]) -> uint {
|
|
self.conn.update(query, params)
|
|
}
|
|
|
|
/// Like `PostgresConnection::transaction`.
|
|
pub fn transaction<'a>(&self) -> PostgresTransaction<'conn> {
|
|
self.conn.quick_query("SAVEPOINT sp");
|
|
PostgresTransaction {
|
|
conn: self.conn,
|
|
commit: RefCell::new(true),
|
|
nested: true
|
|
}
|
|
}
|
|
|
|
/// Like `PostgresConnection::notifications`.
|
|
pub fn notifications<'a>(&'a self) -> PostgresNotificationIterator<'a> {
|
|
self.conn.notifications()
|
|
}
|
|
|
|
/// Determines if the transaction is currently set to commit or roll back.
|
|
pub fn will_commit(&self) -> bool {
|
|
self.commit.with(|x| *x)
|
|
}
|
|
|
|
/// Sets the transaction to commit at its completion.
|
|
pub fn set_commit(&self) {
|
|
self.commit.with_mut(|x| *x = true);
|
|
}
|
|
|
|
/// Sets the transaction to roll back at its completion.
|
|
pub fn set_rollback(&self) {
|
|
self.commit.with_mut(|x| *x = false);
|
|
}
|
|
}
|
|
|
|
/// A trait containing methods that can be called on a prepared statement.
|
|
pub trait PostgresStatement {
|
|
/// Returns a slice containing the expected parameter types.
|
|
fn param_types<'a>(&'a self) -> &'a [PostgresType];
|
|
|
|
/// Returns a slice describing the columns of the result of the query.
|
|
fn result_descriptions<'a>(&'a self) -> &'a [ResultDescription];
|
|
|
|
/// Attempts to execute the prepared statement, returning the number of
|
|
/// rows modified.
|
|
///
|
|
/// If the statement does not modify any rows (e.g. SELECT), 0 is returned.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if the number or types of the provided parameters do not match
|
|
/// the parameters of the statement.
|
|
fn try_update(&self, params: &[&ToSql]) -> Result<uint, PostgresDbError>;
|
|
|
|
/// A convenience function wrapping `try_update`.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if there was an error executing the statement.
|
|
fn update(&self, params: &[&ToSql]) -> uint {
|
|
match self.try_update(params) {
|
|
Ok(count) => count,
|
|
Err(err) => fail!("Error running update\n{}", err.to_str())
|
|
}
|
|
}
|
|
|
|
/// Attempts to execute the prepared statement, returning an iterator over
|
|
/// the resulting rows.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if the number or types of the provided parameters do not match
|
|
/// the parameters of the statement.
|
|
fn try_query<'a>(&'a self, params: &[&ToSql])
|
|
-> Result<PostgresResult<'a>, PostgresDbError>;
|
|
|
|
/// A convenience function wrapping `try_query`.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if there was an error executing the statement.
|
|
fn query<'a>(&'a self, params: &[&ToSql]) -> PostgresResult<'a> {
|
|
match self.try_query(params) {
|
|
Ok(result) => result,
|
|
Err(err) => fail!("Error executing query:\n{}", err.to_str())
|
|
}
|
|
}
|
|
}
|
|
|
|
/// A statement prepared outside of a transaction.
|
|
pub struct NormalPostgresStatement<'conn> {
|
|
priv conn: &'conn PostgresConnection,
|
|
priv name: ~str,
|
|
priv param_types: ~[PostgresType],
|
|
priv result_desc: ~[ResultDescription],
|
|
priv next_portal_id: RefCell<uint>
|
|
}
|
|
|
|
#[unsafe_destructor]
|
|
impl<'conn> Drop for NormalPostgresStatement<'conn> {
|
|
fn drop(&mut self) {
|
|
io_error::cond.trap(|_| {}).inside(|| {
|
|
self.conn.write_messages([
|
|
Close {
|
|
variant: 'S' as u8,
|
|
name: self.name.as_slice()
|
|
},
|
|
Sync]);
|
|
loop {
|
|
match self.conn.read_message() {
|
|
ReadyForQuery { .. } => break,
|
|
_ => {}
|
|
}
|
|
}
|
|
})
|
|
}
|
|
}
|
|
|
|
impl<'conn> NormalPostgresStatement<'conn> {
|
|
fn execute(&self, portal_name: &str, row_limit: uint, params: &[&ToSql])
|
|
-> Option<PostgresDbError> {
|
|
let mut formats = ~[];
|
|
let mut values = ~[];
|
|
assert!(self.param_types.len() == params.len(),
|
|
"Expected {} parameters but found {}",
|
|
self.param_types.len(), params.len());
|
|
for (¶m, &ty) in params.iter().zip(self.param_types.iter()) {
|
|
let (format, value) = param.to_sql(ty);
|
|
formats.push(format as i16);
|
|
values.push(value);
|
|
};
|
|
|
|
let result_formats: ~[i16] = self.result_desc.iter().map(|desc| {
|
|
desc.ty.result_format() as i16
|
|
}).collect();
|
|
|
|
self.conn.write_messages([
|
|
Bind {
|
|
portal: portal_name,
|
|
statement: self.name.as_slice(),
|
|
formats: formats,
|
|
values: values,
|
|
result_formats: result_formats
|
|
},
|
|
Execute {
|
|
portal: portal_name,
|
|
max_rows: row_limit as i32
|
|
},
|
|
Sync]);
|
|
|
|
match self.conn.read_message() {
|
|
BindComplete => None,
|
|
ErrorResponse { fields } => {
|
|
self.conn.wait_for_ready();
|
|
Some(PostgresDbError::new(fields))
|
|
}
|
|
_ => unreachable!()
|
|
}
|
|
}
|
|
|
|
fn try_lazy_query<'a>(&'a self, row_limit: uint, params: &[&ToSql])
|
|
-> Result<PostgresResult<'a>, PostgresDbError> {
|
|
let id = self.next_portal_id.with_mut(|x| { *x += 1; *x - 1 });
|
|
let portal_name = format!("{}_portal_{}", self.name, id);
|
|
|
|
match self.execute(portal_name, row_limit, params) {
|
|
Some(err) => return Err(err),
|
|
None => {}
|
|
}
|
|
|
|
let mut result = PostgresResult {
|
|
stmt: self,
|
|
name: portal_name,
|
|
data: RingBuf::new(),
|
|
row_limit: row_limit,
|
|
more_rows: true
|
|
};
|
|
result.read_rows();
|
|
|
|
Ok(result)
|
|
}
|
|
}
|
|
|
|
impl<'conn> PostgresStatement for NormalPostgresStatement<'conn> {
|
|
fn param_types<'a>(&'a self) -> &'a [PostgresType] {
|
|
self.param_types.as_slice()
|
|
}
|
|
|
|
fn result_descriptions<'a>(&'a self) -> &'a [ResultDescription] {
|
|
self.result_desc.as_slice()
|
|
}
|
|
|
|
fn try_update(&self, params: &[&ToSql])
|
|
-> Result<uint, PostgresDbError> {
|
|
match self.execute("", 0, params) {
|
|
Some(err) => {
|
|
return Err(err);
|
|
}
|
|
None => {}
|
|
}
|
|
|
|
let num;
|
|
loop {
|
|
match self.conn.read_message() {
|
|
DataRow { .. } => {}
|
|
ErrorResponse { fields } => {
|
|
self.conn.wait_for_ready();
|
|
return Err(PostgresDbError::new(fields));
|
|
}
|
|
CommandComplete { tag } => {
|
|
let s = tag.split(' ').last().unwrap();
|
|
num = match FromStr::from_str(s) {
|
|
None => 0,
|
|
Some(n) => n
|
|
};
|
|
break;
|
|
}
|
|
EmptyQueryResponse => {
|
|
num = 0;
|
|
break;
|
|
}
|
|
_ => unreachable!()
|
|
}
|
|
}
|
|
self.conn.wait_for_ready();
|
|
|
|
Ok(num)
|
|
}
|
|
|
|
fn try_query<'a>(&'a self, params: &[&ToSql])
|
|
-> Result<PostgresResult<'a>, PostgresDbError> {
|
|
self.try_lazy_query(0, params)
|
|
}
|
|
}
|
|
|
|
/// Information about a column of the result of a query.
|
|
#[deriving(Eq)]
|
|
pub struct ResultDescription {
|
|
/// The name of the column
|
|
name: ~str,
|
|
/// The type of the data in the column
|
|
ty: PostgresType
|
|
}
|
|
|
|
impl ResultDescription {
|
|
fn from_row_description_entry(row: RowDescriptionEntry)
|
|
-> ResultDescription {
|
|
let RowDescriptionEntry { name, type_oid, .. } = row;
|
|
|
|
ResultDescription {
|
|
name: name,
|
|
ty: PostgresType::from_oid(type_oid)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// A statement prepared inside of a transaction.
|
|
///
|
|
/// Provides additional functionality over a `NormalPostgresStatement`.
|
|
pub struct TransactionalPostgresStatement<'conn> {
|
|
priv stmt: NormalPostgresStatement<'conn>
|
|
}
|
|
|
|
impl<'conn> PostgresStatement for TransactionalPostgresStatement<'conn> {
|
|
fn param_types<'a>(&'a self) -> &'a [PostgresType] {
|
|
self.stmt.param_types()
|
|
}
|
|
|
|
fn result_descriptions<'a>(&'a self) -> &'a [ResultDescription] {
|
|
self.stmt.result_descriptions()
|
|
}
|
|
|
|
fn try_update(&self, params: &[&ToSql]) -> Result<uint, PostgresDbError> {
|
|
self.stmt.try_update(params)
|
|
}
|
|
|
|
fn try_query<'a>(&'a self, params: &[&ToSql])
|
|
-> Result<PostgresResult<'a>, PostgresDbError> {
|
|
self.stmt.try_query(params)
|
|
}
|
|
}
|
|
|
|
impl<'conn> TransactionalPostgresStatement<'conn> {
|
|
/// Attempts to execute the prepared statement, returning a lazily loaded
|
|
/// iterator over the resulting rows.
|
|
///
|
|
/// No more than `row_limit` rows will be stored in memory at a time. Rows
|
|
/// will be pulled from the database in batches of `row_limit` as needed.
|
|
/// If `row_limit` is 0, `try_lazy_query` is equivalent to `try_query`.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if the number or types of the provided parameters do not match
|
|
/// the parameters of the statement.
|
|
pub fn try_lazy_query<'a>(&'a self, row_limit: uint, params: &[&ToSql])
|
|
-> Result<PostgresResult<'a>, PostgresDbError> {
|
|
self.stmt.try_lazy_query(row_limit, params)
|
|
}
|
|
|
|
/// A convenience wrapper around `try_lazy_query`.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if there was an error executing the statement.
|
|
pub fn lazy_query<'a>(&'a self, row_limit: uint, params: &[&ToSql])
|
|
-> PostgresResult<'a> {
|
|
match self.try_lazy_query(row_limit, params) {
|
|
Ok(result) => result,
|
|
Err(err) => fail!("Error executing query:\n{}", err.to_str())
|
|
}
|
|
}
|
|
}
|
|
|
|
/// An iterator over the resulting rows of a query.
|
|
pub struct PostgresResult<'stmt> {
|
|
priv stmt: &'stmt NormalPostgresStatement<'stmt>,
|
|
priv name: ~str,
|
|
priv data: RingBuf<~[Option<~[u8]>]>,
|
|
priv row_limit: uint,
|
|
priv more_rows: bool
|
|
}
|
|
|
|
#[unsafe_destructor]
|
|
impl<'stmt> Drop for PostgresResult<'stmt> {
|
|
fn drop(&mut self) {
|
|
io_error::cond.trap(|_| {}).inside(|| {
|
|
self.stmt.conn.write_messages([
|
|
Close {
|
|
variant: 'P' as u8,
|
|
name: self.name.as_slice()
|
|
},
|
|
Sync]);
|
|
loop {
|
|
match self.stmt.conn.read_message() {
|
|
ReadyForQuery { .. } => break,
|
|
_ => {}
|
|
}
|
|
}
|
|
})
|
|
}
|
|
}
|
|
|
|
impl<'stmt> PostgresResult<'stmt> {
|
|
fn read_rows(&mut self) {
|
|
loop {
|
|
match self.stmt.conn.read_message() {
|
|
EmptyQueryResponse |
|
|
CommandComplete { .. } => {
|
|
self.more_rows = false;
|
|
break;
|
|
},
|
|
PortalSuspended => {
|
|
self.more_rows = true;
|
|
break;
|
|
},
|
|
DataRow { row } => self.data.push_back(row),
|
|
_ => unreachable!()
|
|
}
|
|
}
|
|
self.stmt.conn.wait_for_ready();
|
|
}
|
|
|
|
fn execute(&mut self) {
|
|
self.stmt.conn.write_messages([
|
|
Execute {
|
|
portal: self.name,
|
|
max_rows: self.row_limit as i32
|
|
},
|
|
Sync]);
|
|
self.read_rows();
|
|
}
|
|
}
|
|
|
|
impl<'stmt> Iterator<PostgresRow<'stmt>> for PostgresResult<'stmt> {
|
|
fn next(&mut self) -> Option<PostgresRow<'stmt>> {
|
|
if self.data.is_empty() && self.more_rows {
|
|
self.execute();
|
|
}
|
|
|
|
self.data.pop_front().map(|row| {
|
|
PostgresRow {
|
|
stmt: self.stmt,
|
|
data: row
|
|
}
|
|
})
|
|
}
|
|
}
|
|
|
|
/// A single result row of a query.
|
|
///
|
|
/// A value can be accessed by the name or index of its column, though access
|
|
/// by index is more efficient. Rows are 1-indexed.
|
|
///
|
|
/// ```rust
|
|
/// let foo: i32 = row[1];
|
|
/// let bar: ~str = row["bar"];
|
|
/// ```
|
|
pub struct PostgresRow<'stmt> {
|
|
priv stmt: &'stmt NormalPostgresStatement<'stmt>,
|
|
priv data: ~[Option<~[u8]>]
|
|
}
|
|
|
|
impl<'stmt> Container for PostgresRow<'stmt> {
|
|
#[inline]
|
|
fn len(&self) -> uint {
|
|
self.data.len()
|
|
}
|
|
}
|
|
|
|
impl<'stmt, I: RowIndex, T: FromSql> Index<I, T> for PostgresRow<'stmt> {
|
|
#[inline]
|
|
fn index(&self, idx: &I) -> T {
|
|
let idx = idx.idx(self.stmt);
|
|
FromSql::from_sql(self.stmt.result_desc[idx].ty, &self.data[idx])
|
|
}
|
|
}
|
|
|
|
/// A trait implemented by types that can index into columns of a row.
|
|
pub trait RowIndex {
|
|
/// Returns the index of the appropriate column.
|
|
///
|
|
/// # Failure
|
|
///
|
|
/// Fails if there is no corresponding column.
|
|
fn idx(&self, stmt: &NormalPostgresStatement) -> uint;
|
|
}
|
|
|
|
impl RowIndex for uint {
|
|
#[inline]
|
|
fn idx(&self, _stmt: &NormalPostgresStatement) -> uint {
|
|
assert!(*self != 0, "out of bounds row access");
|
|
*self - 1
|
|
}
|
|
}
|
|
|
|
// This is a convenience as the 1 in get[1] resolves to int :(
|
|
impl RowIndex for int {
|
|
#[inline]
|
|
fn idx(&self, _stmt: &NormalPostgresStatement) -> uint {
|
|
assert!(*self >= 1, "out of bounds row access");
|
|
(*self - 1) as uint
|
|
}
|
|
}
|
|
|
|
impl<'a> RowIndex for &'a str {
|
|
fn idx(&self, stmt: &NormalPostgresStatement) -> uint {
|
|
for (i, desc) in stmt.result_descriptions().iter().enumerate() {
|
|
if desc.name.as_slice() == *self {
|
|
return i;
|
|
}
|
|
}
|
|
fail!("There is no column with name {}", *self);
|
|
}
|
|
}
|