runtime: add fd_rent_lists.h

Co-authored-by: Richard Patel <[email protected]>

src/flamenco/runtime/Local.mk

@@ -0,0 +1,3 @@
+ifdef FD_HAS_INT128
+$(call add-hdrs,fd_rent_lists.h)
+endif

src/flamenco/runtime/fd_rent_lists.h

@@ -0,0 +1,65 @@
+#ifndef HEADER_fd_src_flamenco_runtime_fd_rent_lists_h
+#define HEADER_fd_src_flamenco_runtime_fd_rent_lists_h
+
+/* fd_rent_lists.h provides APIs for managing rent partitions.  Rent
+   partitions are sorted buckets containing the addresses of rent
+   paying accounts.  Due to be removed when rent collection is
+   disabled on Solana mainnet. */
+
+#include "../fd_flamenco_base.h"
+
+static inline ulong
+fd_rent_partition_width( ulong slots_per_epoch ) {
+  if( FD_UNLIKELY( slots_per_epoch==1UL ) ) return ULONG_MAX;
+  return (ULONG_MAX - slots_per_epoch + 1UL) / slots_per_epoch + 1UL;
+}
+
+/* fd_rent_key_to_partition returns the partition index that a pubkey
+   falls into.  Returns ULONG_MAX if this key is not part of any
+   partition.  Loosely corresponds to Bank::partition_from_pubkey @*/
+
+static inline ulong
+fd_rent_key_to_partition( ulong key,
+                          ulong part_width,
+                          ulong part_cnt ) {
+
+  if( part_cnt==1UL ) return 0UL;
+  if( key==0UL      ) return 0UL;
+
+  ulong  part = key / part_width;
+         part = fd_ulong_if( part>=part_cnt, part_cnt-1UL, part );
+  return part;
+
+}
+
+/* fd_rent_partition_to_key returns the lower bound (inclusive) of the
+   pubkey range that this rent partition spans.  Loosely corresponds to
+   Bank::pubkey_range_from_partition.  if opt_last_key!=NULL then
+   *opt_last_key is the last key of this partition.  This is not
+   necessarily (return_value + part_width). */
+
+static inline ulong
+fd_rent_partition_to_key( ulong   partition_idx,
+                          ulong   part_width,
+                          ulong   part_cnt,
+                          ulong * opt_last_key ) {
+
+  ulong key0;
+  ulong key1;
+
+  if( part_cnt<=1UL ) {
+    key0 = 0UL;
+    key1 = ULONG_MAX;
+  } else {
+    key0 = partition_idx * part_width;
+    key1 = fd_ulong_if( partition_idx==part_cnt-1UL,
+                        ULONG_MAX,
+                        key0 + part_width - 1UL );
+  }
+
+  if( opt_last_key ) *opt_last_key = key1;
+  return key0;
+
+}
+
+#endif /* HEADER_fd_src_flamenco_runtime_fd_rent_lists_h */