| 1 | use crate::block::{BlockCell, ClientID, GC}; |
| 2 | use crate::{TransactionMut, ID}; |
| 3 | use std::collections::HashMap; |
| 4 | |
| 5 | #[derive(Default)] |
| 6 | pub(crate) struct GCCollector { |
| 7 | items: HashMap<ClientID, Vec<u32>>, |
| 8 | } |
| 9 | |
| 10 | impl GCCollector { |
| 11 | /// Garbage collect all blocks deleted within current transaction scope. |
| 12 | pub fn collect(txn: &mut TransactionMut) { |
| 13 | let mut gc = Self::default(); |
| 14 | gc.mark_in_scope(txn); |
| 15 | gc.collect_all_marked(txn); |
| 16 | } |
| 17 | |
| 18 | /// Garbage collect all deleted blocks from current transaction's document store. |
| 19 | pub fn collect_all(txn: &mut TransactionMut) { |
| 20 | let mut gc = Self::default(); |
| 21 | gc.mark_all(txn); |
| 22 | gc.collect_all_marked(txn); |
| 23 | } |
| 24 | |
| 25 | /// Mark deleted items based on a current transaction delete set. |
| 26 | fn mark_in_scope(&mut self, txn: &mut TransactionMut) { |
| 27 | for (client, range) in txn.delete_set.iter() { |
| 28 | if let Some(blocks) = txn.store.blocks.get_client_mut(client) { |
| 29 | for delete_item in range.iter().rev() { |
| 30 | let mut start = delete_item.start; |
| 31 | if let Some(mut i) = blocks.find_pivot(start) { |
| 32 | while i < blocks.len() { |
| 33 | let block = &mut blocks[i]; |
| 34 | let len = block.len(); |
| 35 | start += len; |
| 36 | if start > delete_item.end { |
| 37 | break; |
| 38 | } else { |
| 39 | if let BlockCell::Block(item) = block { |
| 40 | item.gc(self, false); |
| 41 | } |
| 42 | i += 1; |
| 43 | } |
| 44 | } |
| 45 | } |
| 46 | } |
| 47 | } |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | fn mark_all(&mut self, txn: &mut TransactionMut) { |
| 52 | for (_, client_blocks) in txn.store.blocks.iter_mut() { |
| 53 | for block in client_blocks.iter_mut() { |
| 54 | if let BlockCell::Block(item) = block { |
| 55 | if item.is_deleted() { |
| 56 | item.gc(self, false); |
| 57 | txn.merge_blocks.push(item.id); |
| 58 | } |
| 59 | } |
| 60 | } |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | /// Marks item with a given [ID] as a candidate for being GCed. |
| 65 | pub(crate) fn mark(&mut self, id: &ID) { |
| 66 | let client = self.items.entry(id.client).or_default(); |
| 67 | client.push(id.clock); |
| 68 | } |
| 69 | |
| 70 | /// Garbage collects all items marked for GC. |
| 71 | fn collect_all_marked(self, txn: &mut TransactionMut) { |
| 72 | for (client_id, clocks) in self.items.into_iter() { |
| 73 | let client = txn.store.blocks.get_client_blocks_mut(client_id); |
| 74 | for clock in clocks { |
| 75 | if let Some(index) = client.find_pivot(clock) { |
| 76 | let block = &mut client[index]; |
| 77 | if let BlockCell::Block(item) = block { |
| 78 | if item.is_deleted() && !item.info.is_keep() { |
| 79 | let (start, end) = item.clock_range(); |
| 80 | let gc = BlockCell::GC(GC::new(start, end)); |
| 81 | *block = gc; |
| 82 | } |
| 83 | } |
| 84 | } |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | } |
| 89 | |
amadan