72 lines
2.3 KiB
Rust
72 lines
2.3 KiB
Rust
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use crate::client::InnerClient;
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use crate::codec::FrontendMessage;
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use crate::connection::{Request, RequestMessages};
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use crate::types::{Oid, Type};
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use crate::{Column, Error, Statement};
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use fallible_iterator::FallibleIterator;
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use futures::StreamExt;
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use postgres_protocol::message::backend::Message;
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use postgres_protocol::message::frontend;
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use std::sync::atomic::{AtomicUsize, Ordering};
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use std::sync::Arc;
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static NEXT_ID: AtomicUsize = AtomicUsize::new(0);
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pub async fn prepare(
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client: Arc<InnerClient>,
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query: &str,
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types: &[Type],
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) -> Result<Statement, Error> {
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let name = format!("s{}", NEXT_ID.fetch_add(1, Ordering::SeqCst));
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let mut buf = vec![];
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frontend::parse(&name, query, types.iter().map(Type::oid), &mut buf).map_err(Error::encode)?;
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frontend::describe(b'S', &name, &mut buf).map_err(Error::encode)?;
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frontend::sync(&mut buf);
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let mut responses = client.send(RequestMessages::Single(FrontendMessage::Raw(buf)))?;
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match responses.next().await? {
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Message::ParseComplete => {}
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_ => return Err(Error::unexpected_message()),
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}
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let parameter_description = match responses.next().await? {
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Message::ParameterDescription(body) => body,
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_ => return Err(Error::unexpected_message()),
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};
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let row_description = match responses.next().await? {
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Message::RowDescription(body) => Some(body),
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Message::NoData => None,
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_ => return Err(Error::unexpected_message()),
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};
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let mut parameters = vec![];
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let mut it = parameter_description.parameters();
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while let Some(oid) = it.next().map_err(Error::parse)? {
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let type_ = get_type(&client, oid).await?;
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parameters.push(type_);
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}
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let mut columns = vec![];
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if let Some(row_description) = row_description {
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let mut it = row_description.fields();
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while let Some(field) = it.next().map_err(Error::parse)? {
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let type_ = get_type(&client, field.type_oid()).await?;
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let column = Column::new(field.name().to_string(), type_);
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columns.push(column);
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}
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}
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Ok(Statement::new(&client, name, parameters, columns))
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}
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async fn get_type(client: &InnerClient, oid: Oid) -> Result<Type, Error> {
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if let Some(type_) = Type::from_oid(oid) {
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return Ok(type_);
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}
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unimplemented!()
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}
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