use std::sync::Arc;
use sha2::{Digest, Sha256};
use super::config::MAX_MUTATIONS;
use super::manager::{Inner, State, Target};
use super::receipts::ReceiptState;
use super::{MutationId, MutationReceipt, MutationValue, StagedFile, StorageManager};
use crate::{Error, Identifier, MemorySize, Result};
pub(super) struct Deletion {
pub(super) work: Arc<DeleteWork>,
pub(super) bytes: usize,
failure: Option<Arc<Error>>,
}
pub(super) struct DeleteWork {
target: Target,
pub(super) file: StagedFile,
pub(super) receipt: MutationReceipt,
}
impl<C> StorageManager<C> {
pub async fn delete_file_once(&self, mutation: &MutationId, file: &StagedFile) -> Result<StagedFile> {
self.inner.primary.history().check(&file.history)?;
if !self.inner.primary.supports_mutation_receipts() || !self.inner.primary.supports_file_deletion() {
return Err(invalid("backend must support durable deletion"));
}
let fingerprint = fingerprint(file);
let mut retry = true;
let mut completion = None;
let mut changed = self.inner.changed.subscribe();
loop {
let mut notify = false;
{
let mut state = self.inner.state.lock().unwrap();
if state.status.closing {
return Err(Error::Closing { domain: "file deletion" });
}
if !state.ready || !state.status.running {
return Err(Error::NotReady { domain: "file deletion" });
}
match state.receipts.lookup(mutation, &fingerprint, completion.as_ref())? {
ReceiptState::Complete(value) => return value.deleted(),
ReceiptState::Pending => {
if completion.is_none() {
let owner = state.receipts.completion(mutation);
completion = Some(owner);
}
let deletion = state.deletions.get(mutation).ok_or_else(|| invalid("pending identity owns different work"))?;
if let Some(source) = deletion.failure.clone() {
if !retry {
return Err(Error::Persistence { source });
}
if let Some(other) = &state.status.failure
&& !Arc::ptr_eq(other, &source)
{
return Err(Error::Persistence { source: other.clone() });
}
state.deletions.get_mut(mutation).unwrap().failure = None;
state.status.failure = None;
state.retry = state.retry.wrapping_add(1);
notify = true;
} else if let Some(source) = &state.status.failure {
return Err(Error::Persistence { source: source.clone() });
}
retry = false;
}
ReceiptState::Missing => {
if let Some(source) = &state.status.failure {
return Err(Error::Persistence { source: source.clone() });
}
if state.files.values().any(|active| active.identifies(file)) {
tracing::error!(file = %file.id, reason = "active producer", "file deletion rejected");
return Err(invalid("active production must finish or abandon before deletion"));
}
if state.deleting(&file.id) {
return Err(invalid("another deletion owns this file"));
}
if state.deletions.len() >= MAX_MUTATIONS.get() {
return Err(exhausted());
}
let bytes = crate::btree_map_memory::<MutationId, Deletion>(1)
.saturating_add(std::mem::size_of::<DeleteWork>())
.saturating_add(std::mem::size_of::<MutationReceipt>())
.saturating_add(std::mem::size_of::<MutationValue>())
.saturating_add(mutation.memory_size().saturating_mul(2))
.saturating_add(file.memory_size().saturating_mul(2))
.saturating_add(2 * std::mem::size_of::<usize>());
state.collect();
let capacity = self.inner.settings.budget.read_memory_bytes.get();
if bytes > capacity || state.status.read_bytes > capacity - bytes {
return Err(exhausted());
}
let outcome = MutationValue::Deleted(file.clone());
state.receipts.insert(mutation, fingerprint, outcome.memory_size())?;
let owner = state.receipts.completion(mutation);
completion = Some(owner);
let receipt = state.receipts.prepared(mutation, outcome);
let target = state.data_accepted;
state.deletions.insert(
mutation.clone(),
Deletion { work: Arc::new(DeleteWork { target, file: file.clone(), receipt }), bytes, failure: None },
);
retry = false;
notify = true;
}
}
state.collect();
}
if notify {
self.inner.notify();
}
changed.changed().await.map_err(|_| Error::Closing { domain: "file deletion" })?;
}
}
pub(super) async fn settle_deletions(&self) -> Result<()> {
let mut changed = self.inner.changed.subscribe();
{
let mut state = self.inner.state.lock().unwrap();
if state.deletions.is_empty() {
return Ok(());
}
for deletion in state.deletions.values_mut() {
deletion.failure = None;
}
state.status.failure = None;
state.retry = state.retry.wrapping_add(1);
}
self.inner.notify();
loop {
{
let state = self.inner.state.lock().unwrap();
if state.deletions.is_empty() {
return Ok(());
}
if let Some(source) = &state.status.failure {
return Err(Error::Persistence { source: source.clone() });
}
if !state.status.running {
return Err(Error::NotReady { domain: "file deletion worker" });
}
}
changed.changed().await.map_err(|_| Error::Closing { domain: "file deletion" })?;
}
}
}
impl State {
pub(super) fn deleting(&self, file: &Identifier) -> bool {
self.deletions.values().any(|deletion| deletion.work.file.id == *file)
}
pub(super) fn request_deletions(&mut self) {
for deletion in self.deletions.values().filter(|deletion| deletion.failure.is_none()) {
let target = deletion.work.target;
if target.index > self.data_flushed && self.data_request.is_none_or(|current| target.index < current.index) {
self.data_request = Some(target);
}
}
}
pub(super) fn deletion_action(&self) -> Option<Arc<DeleteWork>> {
self.deletions
.values()
.find(|deletion| deletion.failure.is_none() && deletion.work.target.index <= self.data_flushed)
.map(|deletion| deletion.work.clone())
}
pub(super) fn deleting_data(&self, index: u64) -> bool {
self.deletions.values().any(|deletion| deletion.failure.is_none() && deletion.work.target.index >= index)
}
pub(super) fn deletion_failed(&mut self, mutation: &MutationId, source: Arc<Error>) {
if let Some(deletion) = self.deletions.get_mut(mutation) {
tracing::error!(file = %deletion.work.file.id, window = %mutation.window, mutation = %mutation.key, error = %source, reason = "file deletion failed", "file deletion retained for retry");
deletion.failure = Some(source);
}
}
pub(super) fn deletion_data_failed(&mut self, index: u64, source: Arc<Error>) {
for deletion in self.deletions.values_mut().filter(|deletion| deletion.work.target.index >= index) {
deletion.failure = Some(source.clone());
}
}
}
impl DeleteWork {
pub(super) async fn perform(&self, inner: &Arc<Inner>) -> Result<()> {
inner.bounded(inner.primary.delete_file(&self.file)).await?;
inner.bounded(inner.primary.save_mutations(std::slice::from_ref(&self.receipt))).await?;
tracing::info!(file = %self.file.id, mutation = %self.receipt.mutation.key, reason = "explicit deletion", "file deleted");
Ok(())
}
}
fn fingerprint(file: &StagedFile) -> [u8; 32] {
let mut hash = Sha256::new();
hash.update(b"storage.delete_file:v1\0");
for bytes in [file.history.store.as_str().as_bytes(), file.history.epoch.as_str().as_bytes(), file.id.as_str().as_bytes()] {
hash.update((bytes.len() as u64).to_le_bytes());
hash.update(bytes);
}
hash.finalize().into()
}
fn invalid(reason: &'static str) -> Error {
Error::InvalidInput { field: "file deletion", reason }
}
fn exhausted() -> Error {
Error::ResourceExhausted { resource: "file deletion requests" }
}