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use crate::{
proto::rpcdb::{self, database_client::DatabaseClient},
subnet::rpc::database::{self, DatabaseError},
};
use std::io::{Error, ErrorKind, Result};
use num_traits::FromPrimitive;
use tonic::transport::Channel;
use crate::subnet::rpc::database::iterator::BoxedIterator;
pub struct Iterator {
id: u64,
data: Vec<rpcdb::PutRequest>,
error: Option<Error>,
db: DatabaseClient<Channel>,
}
impl Iterator {
pub fn new(db: DatabaseClient<Channel>, id: u64) -> BoxedIterator {
Box::new(Self {
id,
data: vec![],
error: None,
db,
})
}
}
#[tonic::async_trait]
impl database::iterator::Iterator for Iterator {
async fn next(&mut self) -> Result<bool> {
let mut db = self.db.clone();
if self.data.len() > 1 {
self.data.drain(0..1);
return Ok(true);
}
let resp = db
.iterator_next(rpcdb::IteratorNextRequest { id: self.id })
.await;
if resp.is_err() {
self.error = Some(Error::new(
ErrorKind::Other,
format!("iterator next failed: {}", resp.unwrap_err()),
));
return Ok(false);
}
self.data = resp.unwrap().into_inner().data;
Ok(self.data.len() > 0)
}
async fn error(&mut self) -> Result<()> {
let mut db = self.db.clone();
if let Some(err) = &self.error {
return Err(Error::new(err.kind(), err.to_string()));
}
let resp = db
.iterator_error(rpcdb::IteratorErrorRequest { id: self.id })
.await;
if resp.is_err() {
self.error = Some(Error::new(
ErrorKind::Other,
format!("iterator next failed: {}", resp.unwrap_err()),
));
} else {
let err = DatabaseError::from_u32(resp.unwrap().into_inner().err);
match err {
Some(DatabaseError::None) => {}
Some(DatabaseError::Closed) => {
self.error = Some(Error::new(ErrorKind::Other, "database closed"))
}
Some(DatabaseError::NotFound) => {
self.error = Some(Error::new(ErrorKind::NotFound, "not found"))
}
_ => self.error = Some(Error::new(ErrorKind::Other, "unexpected database error")),
}
}
if let Some(err) = &self.error {
return Err(Error::new(err.kind(), err.to_string()));
}
Ok(())
}
async fn key(&self) -> Result<&[u8]> {
if self.data.is_empty() {
return Ok(&[]);
}
Ok(&self.data[0].key)
}
async fn value(&self) -> Result<&[u8]> {
if self.data.is_empty() {
return Ok(&[]);
}
Ok(&self.data[0].value)
}
async fn release(&mut self) {
let mut db = self.db.clone();
let resp = db
.iterator_release(rpcdb::IteratorReleaseRequest { id: self.id })
.await;
if resp.is_err() {
self.error = Some(Error::new(
ErrorKind::Other,
format!("iterator release failed: {}", resp.unwrap_err()),
));
} else {
let err = DatabaseError::from_u32(resp.unwrap().into_inner().err);
match err {
Some(DatabaseError::None) => {}
Some(DatabaseError::Closed) => {
self.error = Some(Error::new(ErrorKind::Other, "database closed"))
}
Some(DatabaseError::NotFound) => {
self.error = Some(Error::new(ErrorKind::NotFound, "not found"))
}
_ => self.error = Some(Error::new(ErrorKind::Other, "unexpected database error")),
}
}
}
}