add new realloc ix

name-service/program/src/instruction.rs

@@ -89,6 +89,20 @@ pub enum NameRegistryInstruction {
     ///   2. `[writeable]` Refund account
     ///
     Delete,
+
+    /// Realloc the data of a name record.
+    ///
+    /// The space change cannot be more than `MAX_PERMITTED_DATA_LENGTH` different than
+    /// current `space`.
+    ///
+    /// Accounts expected by this instruction:
+    ///   0. `[writeable]` Name record to be reallocated
+    ///   1. `[signer]` Account owner
+    ///
+    Realloc {
+        /// Number of bytes of memory to allocate in addition to the `NameRecordHeader`.
+        space: u32,
+    },
 }
 
 #[allow(clippy::too_many_arguments)]
@@ -201,3 +215,26 @@ pub fn delete(
         data,
     })
 }
+
+pub fn realloc(
+    payer_key: Pubkey,
+    name_service_program_id: Pubkey,
+    name_account_key: Pubkey,
+    name_owner_key: Pubkey,
+    space: u32,
+) -> Result<Instruction, ProgramError> {
+    let instruction_data = NameRegistryInstruction::Realloc { space };
+    let data = instruction_data.try_to_vec().unwrap();
+    let accounts = vec![
+        AccountMeta::new_readonly(system_program::id(), false),
+        AccountMeta::new(payer_key, true),
+        AccountMeta::new(name_account_key, false),
+        AccountMeta::new_readonly(name_owner_key, true),
+    ];
+
+    Ok(Instruction {
+        program_id: name_service_program_id,
+        accounts,
+        data,
+    })
+}

name-service/program/src/processor.rs

@@ -1,3 +1,6 @@
+use solana_program::rent::Rent;
+use solana_program::sysvar::Sysvar;
+use std::cmp::Ordering;
 use {
     crate::{
         instruction::NameRegistryInstruction,
@@ -239,6 +242,61 @@ impl Processor {
         Ok(())
     }
 
+    fn process_realloc(accounts: &[AccountInfo], space: u32) -> ProgramResult {
+        let accounts_iter = &mut accounts.iter();
+        let system_program = next_account_info(accounts_iter)?;
+        let payer_account = next_account_info(accounts_iter)?;
+        let name_account = next_account_info(accounts_iter)?;
+        let name_owner = next_account_info(accounts_iter)?;
+
+        let name_record_header = NameRecordHeader::unpack_from_slice(&name_account.data.borrow())?;
+
+        // Verifications
+        if !name_owner.is_signer || name_record_header.owner != *name_owner.key {
+            msg!("The given name owner is incorrect or not a signer.");
+            return Err(ProgramError::InvalidArgument);
+        }
+
+        let new_space = NameRecordHeader::LEN + space as usize;
+        let required_lamports = Rent::get()?.minimum_balance(new_space);
+        match name_account.lamports().cmp(&required_lamports) {
+            Ordering::Less => {
+                let lamports_to_add = required_lamports - name_account.lamports();
+                invoke(
+                    &system_instruction::transfer(
+                        payer_account.key,
+                        name_account.key,
+                        lamports_to_add,
+                    ),
+                    &[
+                        payer_account.clone(),
+                        name_account.clone(),
+                        system_program.clone(),
+                    ],
+                )?;
+            }
+            Ordering::Greater => {
+                let lamports_to_remove = name_account.lamports() - required_lamports;
+                invoke(
+                    &system_instruction::transfer(
+                        name_account.key,
+                        payer_account.key,
+                        lamports_to_remove,
+                    ),
+                    &[
+                        name_account.clone(),
+                        payer_account.clone(),
+                        system_program.clone(),
+                    ],
+                )?;
+            }
+            Ordering::Equal => {}
+        }
+        // Max data increase is checked in realloc. No need to check here.
+        name_account.realloc(new_space, false)?;
+        Ok(())
+    }
+
     pub fn process_instruction(
         program_id: &Pubkey,
         accounts: &[AccountInfo],
@@ -270,6 +328,10 @@ impl Processor {
                 msg!("Instruction: Delete Name");
                 Processor::process_delete(accounts)?;
             }
+            NameRegistryInstruction::Realloc { space } => {
+                msg!("Instruction: Delete Name");
+                Processor::process_realloc(accounts, space)?;
+            }
         }
         Ok(())
     }