use std::sync::Arc;
use reifydb_core::{
encoded::{key::EncodedKey, row::EncodedRow, shape::RowShape},
interface::{catalog::dictionary::Dictionary, resolved::ResolvedView},
internal_error,
key::{
EncodableKey,
row::{RowKey, RowKeyRange},
},
value::column::{ColumnWithName, buffer::ColumnBuffer, columns::Columns, headers::ColumnHeaders},
};
use reifydb_transaction::{multi::RangeScope, transaction::Transaction};
use reifydb_value::{
fragment::Fragment,
reifydb_assertions,
util::cowvec::CowVec,
value::{row_number::RowNumber, value_type::ValueType},
};
use tracing::instrument;
use super::super::decode_dictionary_columns;
use crate::{
Result,
vm::volcano::query::{QueryContext, QueryNode},
};
pub(crate) struct ViewScanNode {
view: ResolvedView,
context: Option<Arc<QueryContext>>,
headers: ColumnHeaders,
storage_types: Vec<ValueType>,
dictionaries: Vec<Option<Dictionary>>,
shape: Option<RowShape>,
last_key: Option<EncodedKey>,
exhausted: bool,
sorted: bool,
}
impl ViewScanNode {
pub fn new(view: ResolvedView, context: Arc<QueryContext>, rx: &mut Transaction<'_>) -> Result<Self> {
let mut storage_types = Vec::with_capacity(view.columns().len());
let mut dictionaries = Vec::with_capacity(view.columns().len());
for col in view.columns() {
if let Some(dict_id) = col.dictionary_id {
if let Some(dict) = context.services.catalog.find_dictionary(rx, dict_id)? {
storage_types.push(ValueType::DictionaryId);
dictionaries.push(Some(dict));
} else {
storage_types.push(col.constraint.get_type());
dictionaries.push(None);
}
} else {
storage_types.push(col.constraint.get_type());
dictionaries.push(None);
}
}
let headers = ColumnHeaders {
columns: view.columns().iter().map(|col| Fragment::internal(&col.name)).collect(),
};
let sorted = !view.def().sort().is_empty();
Ok(Self {
view,
context: Some(context),
headers,
storage_types,
dictionaries,
shape: None,
last_key: None,
exhausted: false,
sorted,
})
}
fn get_or_load_shape<'a>(&mut self, rx: &mut Transaction<'a>, first_row: &EncodedRow) -> Result<RowShape> {
if let Some(shape) = &self.shape {
return Ok(shape.clone());
}
let fingerprint = first_row.fingerprint();
let stored_ctx = self.context.as_ref().expect("ViewScanNode context not set");
let shape = stored_ctx.services.catalog.get_or_load_row_shape(fingerprint, rx)?.ok_or_else(|| {
internal_error!(
"RowShape with fingerprint {:?} not found for view {}",
fingerprint,
self.view.def().name()
)
})?;
self.shape = Some(shape.clone());
Ok(shape)
}
}
impl QueryNode for ViewScanNode {
#[instrument(name = "volcano::scan::view::initialize", level = "trace", skip_all)]
fn initialize<'a>(&mut self, _rx: &mut Transaction<'a>, _ctx: &QueryContext) -> Result<()> {
Ok(())
}
#[instrument(name = "volcano::scan::view::next", level = "trace", skip_all)]
fn next<'a>(&mut self, rx: &mut Transaction<'a>, _ctx: &mut QueryContext) -> Result<Option<Columns>> {
reifydb_assertions! {
assert!(self.context.is_some(), "ViewScanNode::next() called before initialize()");
}
let stored_ctx = self.context.as_ref().unwrap();
if self.exhausted {
return Ok(None);
}
let batch_size = stored_ctx.batch_size;
let range = RowKeyRange::scan_range(self.view.def().underlying_id(), self.last_key.as_ref());
let mut batch_rows = Vec::new();
let mut row_numbers = Vec::new();
let mut new_last_key = None;
let mut stream = rx.range(range, RangeScope::All, batch_size as usize)?;
for _ in 0..batch_size {
match stream.next() {
Some(Ok(multi)) => {
let row = if self.sorted {
let bytes = multi.key.as_slice();
RowNumber(u64::from_be_bytes(
bytes[bytes.len() - 8..].try_into().unwrap(),
))
} else if let Some(key) = RowKey::decode(&multi.key) {
key.row
} else {
continue;
};
batch_rows.push(multi.row);
row_numbers.push(row);
new_last_key = Some(multi.key);
}
Some(Err(e)) => return Err(e),
None => {
self.exhausted = true;
break;
}
}
}
drop(stream);
if batch_rows.is_empty() {
self.exhausted = true;
if self.last_key.is_none() {
return Ok(Some(Columns::from_catalog_columns(self.view.columns())));
}
return Ok(None);
}
self.last_key = new_last_key;
let storage_columns: Vec<ColumnWithName> = self
.view
.columns()
.iter()
.enumerate()
.map(|(idx, col)| ColumnWithName {
name: Fragment::internal(&col.name),
data: ColumnBuffer::with_capacity(self.storage_types[idx].clone(), 0),
})
.collect();
let mut columns = Columns::with_system_columns(storage_columns, Vec::new(), Vec::new(), Vec::new());
{
let shape = self.get_or_load_shape(rx, &batch_rows[0])?;
columns.append_rows(&shape, batch_rows.into_iter(), row_numbers.clone())?;
}
columns.row_numbers = CowVec::new(row_numbers);
decode_dictionary_columns(&mut columns, &self.dictionaries, rx)?;
Ok(Some(columns))
}
fn headers(&self) -> Option<ColumnHeaders> {
Some(self.headers.clone())
}
}