Adding the RootPage trait to access the raw bytes of a root page (needed in libpijul)

pmeunier

Jul 12, 2021, 9:12 PM

YDHYZA77LFQ7RSKTVOTOQRL7EUSXMWYOSJAE5YAH6HLHE64B75LQC

Dependencies

• [2] SYURNHHL Adding the `put_mut` and `set_left_child` methods
• [3] TJ2R4HAZ Accessing the root pages (unsafely, of course)
• [4] YWFYZNLZ Cleanup + inter-process concurrency
• [5] E4MD6T3L Proofreading and commenting of this crate (massive bug fixes included)
• [6] SO25TWFL A few features for integrating it into Pijul
• [7] OFINGD26 implementing prev() on cursors (+ some cleanup)
• [8] OP6SVMOD Resetting history
• [9] W2MIZD5B Single file databases + CRC for the root pages (checking the other pages makes everything very slow)

Change contents

• replacement in sanakirja/src/lib.rs at line 107
  [4.2997]→[4.6577:6634](∅→∅)
  − pub use environment::{Commit, Env, MutTxn, RootDb, Txn};
  [4.2997]

  [2.2260]
  + pub use environment::{Commit, Env, MutTxn, RootDb, Txn, RootPage};
• edit in sanakirja/src/environment/muttxn.rs at line 619
  [4.4392]

  [4.20978]
  + impl<E: Borrow<Env>, T> RootPage for MutTxn<E, T> {

  + unsafe fn root_page(&self) -> &[u8; 4064] {

  + let env = self.env.borrow();

  + let maps = env.mmaps.lock();

  + let ptr = maps[0].ptr.add(self.root * PAGE_SIZE + GLOBAL_HEADER_SIZE);

  + &*(ptr as *const [u8; 4064])

  + }

  + }

  +
• edit in sanakirja/src/environment/mod.rs at line 562
  [4.106698]

  [4.106698]
  + }

  +

  + /// Access the root page of a transaction.

  + pub trait RootPage {

  + /// The root page of this transaction.

  + unsafe fn root_page(&self) -> &[u8; 4064];
• edit in sanakirja/src/environment/mod.rs at line 570
  [4.106701]

  [4.31080]
  + impl<E: Borrow<Env>> RootPage for Txn<E> {

  + unsafe fn root_page(&self) -> &[u8; 4064] {

  + let env = self.env.borrow();

  + let maps = env.mmaps.lock();

  + let ptr = maps[0].ptr.add(self.root * PAGE_SIZE + GLOBAL_HEADER_SIZE);

  + &*(ptr as *const [u8; 4064])

  + }

  + }

  +
• edit in sanakirja/src/environment/mod.rs at line 630
  [3.671]→[3.671:961](∅→∅),[3.961]→[4.18035:18041](∅→∅),[4.18035]→[4.18035:18041](∅→∅)
  −

  − /// The root page of this transaction.

  − pub unsafe fn root_page(&mut self) -> &[u8; 4064] {

  − let env = self.env.borrow();

  − let maps = env.mmaps.lock();

  − let ptr = maps[0].ptr.add(self.root * PAGE_SIZE + GLOBAL_HEADER_SIZE);

  − &*(ptr as *const [u8; 4064])

  − }