mirrors/limbo
1
0
Fork 0
mirror of https://github.com/tursodatabase/limbo.git synced 2025-08-04 18:18:03 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 13

Refactor read_write_payload_to_page into separate read and write

Browse source 
functions
This commit is contained in:
krishvishal 2025-05-14 13:03:23 +05:30
parent fb9fcb7887
commit f6e814c113
1 changed files with 45 additions and 30 deletions
Download patch file Download diff file Expand all files Collapse all files

75
core/storage/btree.rs
View file

@ -852,7 +852,11 @@ impl BTreeCursor {
if local_amount + offset > local_size as u32 {
local_amount = local_size as u32 - offset;
}
self.read_write_payload_to_page(offset, payload, page, buffer, amount, is_write);
if is_write {
self.write_payload_to_page(offset, local_amount, payload, buffer, page.clone());
} else {
self.read_payload_from_page(offset, local_amount, payload, buffer);
}
offset = 0;
amount -= local_amount;
bytes_processed += local_amount;
@ -979,14 +983,22 @@ impl BTreeCursor {
let payload_offset = 4 + page_offset;
let page_payload = contents.as_ptr();
self.read_write_payload_to_page(
payload_offset as u32,
page_payload,
page.clone(),
buffer,
bytes_to_process,
*is_write,
);
if *is_write {
self.write_payload_to_page(
payload_offset as u32,
bytes_to_process,
page_payload,
buffer,
page.clone(),
);
} else {
self.read_payload_from_page(
payload_offset as u32,
bytes_to_process,
page_payload,
buffer,
);
}
*remaining_to_read -= bytes_to_process;
*buffer_offset += bytes_to_process as usize;
@ -1018,33 +1030,36 @@ impl BTreeCursor {
}
}
/// This function read from a page into a buffer or write from a buffer into a page.
/// copy_to_page: true if writing, false if reading
fn read_payload_from_page(
&self,
payload_offset: u32,
num_bytes: u32,
payload: &[u8],
buffer: &mut Vec<u8>,
) {
buffer.extend_from_slice(
&payload[payload_offset as usize..(payload_offset + num_bytes) as usize],
);
}
/// This function write from a buffer into a page.
/// SAFETY: This function uses unsafe in the write path to write to the page payload directly.
/// - Make sure the page is pointing to valid data ie the page is not evicted from the page-cache.
fn read_write_payload_to_page(
fn write_payload_to_page(
&mut self,
payload_offset: u32,
payload: &[u8],
page: PageRef,
buffer: &mut Vec<u8>,
num_bytes: u32,
copy_to_page: bool,
payload: &[u8],
buffer: &mut Vec<u8>,
page: PageRef,
) {
if copy_to_page {
page.set_dirty();
self.pager.add_dirty(page.get().id);
// This is safe as long as the page is not evicted from the cache.
let payload_mut = unsafe {
std::slice::from_raw_parts_mut(payload.as_ptr() as *mut u8, payload.len())
};
payload_mut[payload_offset as usize..payload_offset as usize + num_bytes as usize]
.copy_from_slice(&buffer[..num_bytes as usize]);
} else {
buffer.extend_from_slice(
&payload[payload_offset as usize..(payload_offset + num_bytes) as usize],
);
}
page.set_dirty();
self.pager.add_dirty(page.get().id);
// SAFETY: This is safe as long as the page is not evicted from the cache.
let payload_mut =
unsafe { std::slice::from_raw_parts_mut(payload.as_ptr() as *mut u8, payload.len()) };
payload_mut[payload_offset as usize..payload_offset as usize + num_bytes as usize]
.copy_from_slice(&buffer[..num_bytes as usize]);
}
/// Move the cursor to the next record and return it.