From 140c21f8a906fda41feb251d0b32b82ea8760652 Mon Sep 17 00:00:00 2001
From: Brooks <brooks@solana.com>
Date: Wed, 28 Feb 2024 16:08:00 -0500
Subject: [PATCH] Removes ReadAccountMapEntry (#35351)

---
 accounts-db/src/accounts_index.rs | 95 +------------------------------
 1 file changed, 1 insertion(+), 94 deletions(-)

diff --git a/accounts-db/src/accounts_index.rs b/accounts-db/src/accounts_index.rs
index 5221ac434..7c4baf1ee 100644
--- a/accounts-db/src/accounts_index.rs
+++ b/accounts-db/src/accounts_index.rs
@@ -13,7 +13,6 @@ use {
         secondary_index::*,
     },
     log::*,
-    ouroboros::self_referencing,
     rand::{thread_rng, Rng},
     rayon::{
         iter::{IntoParallelIterator, ParallelIterator},
@@ -37,7 +36,7 @@ use {
         path::PathBuf,
         sync::{
             atomic::{AtomicBool, AtomicU64, AtomicUsize, Ordering},
-            Arc, Mutex, OnceLock, RwLock, RwLockReadGuard, RwLockWriteGuard,
+            Arc, Mutex, OnceLock, RwLock, RwLockWriteGuard,
         },
     },
     thiserror::Error,
@@ -339,48 +338,6 @@ impl<T: IndexValue> AccountMapEntryInner<T> {
     }
 }
 
-pub enum AccountIndexGetResult<T: IndexValue> {
-    /// (index entry, index in slot list)
-    Found(ReadAccountMapEntry<T>, usize),
-    NotFound,
-}
-
-#[self_referencing]
-pub struct ReadAccountMapEntry<T: IndexValue> {
-    owned_entry: AccountMapEntry<T>,
-    #[borrows(owned_entry)]
-    #[covariant]
-    slot_list_guard: RwLockReadGuard<'this, SlotList<T>>,
-}
-
-impl<T: IndexValue> Debug for ReadAccountMapEntry<T> {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(f, "{:?}", self.borrow_owned_entry())
-    }
-}
-
-impl<T: IndexValue> ReadAccountMapEntry<T> {
-    pub fn from_account_map_entry(account_map_entry: AccountMapEntry<T>) -> Self {
-        ReadAccountMapEntryBuilder {
-            owned_entry: account_map_entry,
-            slot_list_guard_builder: |lock| lock.slot_list.read().unwrap(),
-        }
-        .build()
-    }
-
-    pub fn slot_list(&self) -> &SlotList<T> {
-        self.borrow_slot_list_guard()
-    }
-
-    pub fn ref_count(&self) -> RefCount {
-        self.borrow_owned_entry().ref_count()
-    }
-
-    pub fn addref(&self) {
-        self.borrow_owned_entry().addref();
-    }
-}
-
 /// can be used to pre-allocate structures for insertion into accounts index outside of lock
 pub enum PreAllocatedAccountMapEntry<T: IndexValue> {
     Entry(AccountMapEntry<T>),
@@ -1490,28 +1447,6 @@ impl<T: IndexValue, U: DiskIndexValue + From<T> + Into<T>> AccountsIndex<T, U> {
         });
     }
 
-    /// Get an account
-    /// The latest account that appears in `ancestors` or `roots` is returned.
-    pub fn get(
-        &self,
-        pubkey: &Pubkey,
-        ancestors: Option<&Ancestors>,
-        max_root: Option<Slot>,
-    ) -> AccountIndexGetResult<T> {
-        let read_account_map_entry = self
-            .get_bin(pubkey)
-            .get(pubkey)
-            .map(ReadAccountMapEntry::from_account_map_entry);
-
-        read_account_map_entry
-            .and_then(|locked_entry| {
-                let slot_list = locked_entry.slot_list();
-                self.latest_slot(ancestors, slot_list, max_root)
-                    .map(|found_index| AccountIndexGetResult::Found(locked_entry, found_index))
-            })
-            .unwrap_or(AccountIndexGetResult::NotFound)
-    }
-
     // Get the maximum root <= `max_allowed_root` from the given `slice`
     fn get_newest_root_in_slot_list(
         alive_roots: &RollingBitField,
@@ -2076,34 +2011,6 @@ impl<T: IndexValue, U: DiskIndexValue + From<T> + Into<T>> AccountsIndex<T, U> {
     }
 }
 
-// These functions/fields are only usable from a dev context (i.e. tests and benches)
-#[cfg(feature = "dev-context-only-utils")]
-impl<T: IndexValue> AccountIndexGetResult<T> {
-    pub fn unwrap(self) -> (ReadAccountMapEntry<T>, usize) {
-        match self {
-            AccountIndexGetResult::Found(lock, size) => (lock, size),
-            _ => {
-                panic!("trying to unwrap AccountIndexGetResult with non-Success result");
-            }
-        }
-    }
-
-    pub fn is_none(&self) -> bool {
-        !self.is_some()
-    }
-
-    pub fn is_some(&self) -> bool {
-        matches!(self, AccountIndexGetResult::Found(_lock, _size))
-    }
-
-    pub fn map<V, F: FnOnce((ReadAccountMapEntry<T>, usize)) -> V>(self, f: F) -> Option<V> {
-        match self {
-            AccountIndexGetResult::Found(lock, size) => Some(f((lock, size))),
-            _ => None,
-        }
-    }
-}
-
 #[cfg(test)]
 pub mod tests {
     use {