use crate::client::InnerClient;
use crate::codec::FrontendMessage;
use crate::connection::RequestMessages;
use crate::error::SqlState;
use crate::types::{Field, Kind, Oid, Type};
use crate::{query, slice_iter};
use crate::{Column, Error, Statement};
use bytes::Bytes;
use fallible_iterator::FallibleIterator;
use futures_util::{pin_mut, TryStreamExt};
use log::debug;
use postgres_protocol::message::backend::Message;
use postgres_protocol::message::frontend;
use std::future::Future;
use std::pin::Pin;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
const TYPEINFO_QUERY: &str = "\
SELECT t.typname, t.typtype, t.typelem, r.rngsubtype, t.typbasetype, n.nspname, t.typrelid
FROM pg_catalog.pg_type t
LEFT OUTER JOIN pg_catalog.pg_range r ON r.rngtypid = t.oid
INNER JOIN pg_catalog.pg_namespace n ON t.typnamespace = n.oid
WHERE t.oid = $1
";
const TYPEINFO_FALLBACK_QUERY: &str = "\
SELECT t.typname, t.typtype, t.typelem, NULL::OID, t.typbasetype, n.nspname, t.typrelid
FROM pg_catalog.pg_type t
INNER JOIN pg_catalog.pg_namespace n ON t.typnamespace = n.oid
WHERE t.oid = $1
";
const TYPEINFO_ENUM_QUERY: &str = "\
SELECT enumlabel
FROM pg_catalog.pg_enum
WHERE enumtypid = $1
ORDER BY enumsortorder
";
const TYPEINFO_ENUM_FALLBACK_QUERY: &str = "\
SELECT enumlabel
FROM pg_catalog.pg_enum
WHERE enumtypid = $1
ORDER BY oid
";
const TYPEINFO_COMPOSITE_QUERY: &str = "\
SELECT attname, atttypid
FROM pg_catalog.pg_attribute
WHERE attrelid = $1
AND NOT attisdropped
AND attnum > 0
ORDER BY attnum
";
static NEXT_ID: AtomicUsize = AtomicUsize::new(0);
pub async fn prepare(
client: &Arc<InnerClient>,
query: &str,
types: &[Type],
) -> Result<Statement, Error> {
let name = format!("s{}", NEXT_ID.fetch_add(1, Ordering::SeqCst));
let buf = encode(client, &name, query, types)?;
let mut responses = client.send(RequestMessages::Single(FrontendMessage::Raw(buf)))?;
match responses.next().await? {
Message::ParseComplete => {}
_ => return Err(Error::unexpected_message()),
}
let parameter_description = match responses.next().await? {
Message::ParameterDescription(body) => body,
_ => return Err(Error::unexpected_message()),
};
let row_description = match responses.next().await? {
Message::RowDescription(body) => Some(body),
Message::NoData => None,
_ => return Err(Error::unexpected_message()),
};
let mut parameters = vec![];
let mut it = parameter_description.parameters();
while let Some(oid) = it.next().map_err(Error::parse)? {
let type_ = get_type(client, oid).await?;
parameters.push(type_);
}
let mut columns = vec![];
if let Some(row_description) = row_description {
let mut it = row_description.fields();
while let Some(field) = it.next().map_err(Error::parse)? {
let type_ = get_type(client, field.type_oid()).await?;
let column = Column {
name: field.name().to_string(),
table_oid: Some(field.table_oid()).filter(|n| *n != 0),
column_id: Some(field.column_id()).filter(|n| *n != 0),
r#type: type_,
};
columns.push(column);
}
}
Ok(Statement::new(client, name, parameters, columns))
}
fn prepare_rec<'a>(
client: &'a Arc<InnerClient>,
query: &'a str,
types: &'a [Type],
) -> Pin<Box<dyn Future<Output = Result<Statement, Error>> + 'a + Send>> {
Box::pin(prepare(client, query, types))
}
fn encode(client: &InnerClient, name: &str, query: &str, types: &[Type]) -> Result<Bytes, Error> {
if types.is_empty() {
debug!("preparing query {}: {}", name, query);
} else {
debug!("preparing query {} with types {:?}: {}", name, types, query);
}
client.with_buf(|buf| {
frontend::parse(name, query, types.iter().map(Type::oid), buf).map_err(Error::encode)?;
frontend::describe(b'S', name, buf).map_err(Error::encode)?;
frontend::sync(buf);
Ok(buf.split().freeze())
})
}
pub(crate) async fn get_type(client: &Arc<InnerClient>, oid: Oid) -> Result<Type, Error> {
if let Some(type_) = Type::from_oid(oid) {
return Ok(type_);
}
if let Some(type_) = client.type_(oid) {
return Ok(type_);
}
let stmt = typeinfo_statement(client).await?;
let rows = query::query(client, stmt, slice_iter(&[&oid])).await?;
pin_mut!(rows);
let row = match rows.try_next().await? {
Some(row) => row,
None => return Err(Error::unexpected_message()),
};
let name: String = row.try_get(0)?;
let type_: i8 = row.try_get(1)?;
let elem_oid: Oid = row.try_get(2)?;
let rngsubtype: Option<Oid> = row.try_get(3)?;
let basetype: Oid = row.try_get(4)?;
let schema: String = row.try_get(5)?;
let relid: Oid = row.try_get(6)?;
let kind = if type_ == b'e' as i8 {
let variants = get_enum_variants(client, oid).await?;
Kind::Enum(variants)
} else if type_ == b'p' as i8 {
Kind::Pseudo
} else if basetype != 0 {
let type_ = get_type_rec(client, basetype).await?;
Kind::Domain(type_)
} else if elem_oid != 0 {
let type_ = get_type_rec(client, elem_oid).await?;
Kind::Array(type_)
} else if relid != 0 {
let fields = get_composite_fields(client, relid).await?;
Kind::Composite(fields)
} else if let Some(rngsubtype) = rngsubtype {
let type_ = get_type_rec(client, rngsubtype).await?;
Kind::Range(type_)
} else {
Kind::Simple
};
let type_ = Type::new(name, oid, kind, schema);
client.set_type(oid, &type_);
Ok(type_)
}
fn get_type_rec<'a>(
client: &'a Arc<InnerClient>,
oid: Oid,
) -> Pin<Box<dyn Future<Output = Result<Type, Error>> + Send + 'a>> {
Box::pin(get_type(client, oid))
}
async fn typeinfo_statement(client: &Arc<InnerClient>) -> Result<Statement, Error> {
if let Some(stmt) = client.typeinfo() {
return Ok(stmt);
}
let stmt = match prepare_rec(client, TYPEINFO_QUERY, &[]).await {
Ok(stmt) => stmt,
Err(ref e) if e.code() == Some(&SqlState::UNDEFINED_TABLE) => {
prepare_rec(client, TYPEINFO_FALLBACK_QUERY, &[]).await?
}
Err(e) => return Err(e),
};
client.set_typeinfo(&stmt);
Ok(stmt)
}
async fn get_enum_variants(client: &Arc<InnerClient>, oid: Oid) -> Result<Vec<String>, Error> {
let stmt = typeinfo_enum_statement(client).await?;
query::query(client, stmt, slice_iter(&[&oid]))
.await?
.and_then(|row| async move { row.try_get(0) })
.try_collect()
.await
}
async fn typeinfo_enum_statement(client: &Arc<InnerClient>) -> Result<Statement, Error> {
if let Some(stmt) = client.typeinfo_enum() {
return Ok(stmt);
}
let stmt = match prepare_rec(client, TYPEINFO_ENUM_QUERY, &[]).await {
Ok(stmt) => stmt,
Err(ref e) if e.code() == Some(&SqlState::UNDEFINED_COLUMN) => {
prepare_rec(client, TYPEINFO_ENUM_FALLBACK_QUERY, &[]).await?
}
Err(e) => return Err(e),
};
client.set_typeinfo_enum(&stmt);
Ok(stmt)
}
async fn get_composite_fields(client: &Arc<InnerClient>, oid: Oid) -> Result<Vec<Field>, Error> {
let stmt = typeinfo_composite_statement(client).await?;
let rows = query::query(client, stmt, slice_iter(&[&oid]))
.await?
.try_collect::<Vec<_>>()
.await?;
let mut fields = vec![];
for row in rows {
let name = row.try_get(0)?;
let oid = row.try_get(1)?;
let type_ = get_type_rec(client, oid).await?;
fields.push(Field::new(name, type_));
}
Ok(fields)
}
async fn typeinfo_composite_statement(client: &Arc<InnerClient>) -> Result<Statement, Error> {
if let Some(stmt) = client.typeinfo_composite() {
return Ok(stmt);
}
let stmt = prepare_rec(client, TYPEINFO_COMPOSITE_QUERY, &[]).await?;
client.set_typeinfo_composite(&stmt);
Ok(stmt)
}