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Code Issues Projects Releases Packages Wiki Activity Actions 14

Add local constants for free_page offsets for clarity.

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krishvishal 2025-01-26 22:38:27 +05:30
parent 8a2c5808c2
commit c80007d8a0
1 changed files with 16 additions and 11 deletions
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27
core/storage/pager.rs
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@ -454,6 +454,14 @@ impl Pager {
// Providing a page is optional, if provided it will be used to avoid reading the page from disk.
// This is implemented in accordance with sqlite freepage2() function.
pub fn free_page(&self, page: Option<PageRef>, page_id: usize) -> Result<()> {
const TRUNK_PAGE_HEADER_SIZE: usize = 8;
const LEAF_ENTRY_SIZE: usize = 4;
const RESERVED_SLOTS: usize = 2;
const TRUNK_PAGE_NEXT_PAGE_OFFSET: usize = 0; // Offset to next trunk page pointer
const TRUNK_PAGE_LEAF_COUNT_OFFSET: usize = 4; // Offset to leaf count
if page_id < 2 || page_id > self.db_header.borrow().database_size as usize {
return Err(LimboError::Corrupt(format!(
"Invalid page number {} for free operation",
@ -469,10 +477,6 @@ impl Pager {
None => self.read_page(page_id)?,
};
let page_1 = self.read_page(1)?;
page_1.set_dirty();
self.add_dirty(1);
self.db_header.borrow_mut().freelist_pages += 1;
let trunk_page_id = self.db_header.borrow().freelist_trunk_page;
@ -481,17 +485,18 @@ impl Pager {
// Add as leaf to current trunk
let trunk_page = self.read_page(trunk_page_id as usize)?;
let trunk_page_contents = trunk_page.get().contents.as_ref().unwrap();
let number_of_leaf_pages = trunk_page_contents.read_u32(4);
let max_free_list_entries = (self.usable_size() / 4) - 8;
let number_of_leaf_pages = trunk_page_contents.read_u32(TRUNK_PAGE_LEAF_COUNT_OFFSET);
// Reserve 2 slots for the trunk page header which is 8 bytes or 2*LEAF_ENTRY_SIZE
let max_free_list_entries = (self.usable_size() / LEAF_ENTRY_SIZE) - RESERVED_SLOTS;
if number_of_leaf_pages < max_free_list_entries as u32 {
trunk_page.set_dirty();
self.add_dirty(trunk_page_id as usize);
trunk_page_contents.write_u32(4, number_of_leaf_pages + 1);
trunk_page_contents.write_u32(TRUNK_PAGE_LEAF_COUNT_OFFSET, number_of_leaf_pages + 1);
trunk_page_contents
.write_u32((8 + (number_of_leaf_pages * 4)) as usize, page_id as u32);
.write_u32(TRUNK_PAGE_HEADER_SIZE + (number_of_leaf_pages as usize * LEAF_ENTRY_SIZE), page_id as u32);
page.clear_uptodate();
page.clear_loaded();
@ -505,9 +510,9 @@ impl Pager {
let contents = page.get().contents.as_mut().unwrap();
// Point to previous trunk
contents.write_u32(0, trunk_page_id);
contents.write_u32(TRUNK_PAGE_NEXT_PAGE_OFFSET, trunk_page_id);
// Zero leaf count
contents.write_u32(4, 0);
contents.write_u32(TRUNK_PAGE_LEAF_COUNT_OFFSET, 0);
// Update page 1 to point to new trunk
self.db_header.borrow_mut().freelist_trunk_page = page_id as u32;
// Clear flags