Round the contract code rent discount up. (#1631)

### What

Round the contract code rent discount up.

That's a protocol bug that will be included in p26.

### Why

Rounding down was inconsistent with the rest computations and resulted
in missing 1 stroop from rent computations from time to time.

### Known limitations

N/A

Author: dmkozh

soroban-env-host/src/fees.rs

@@ -389,7 +389,7 @@ fn rent_fee_per_entry_change(
         ));
     }
     if entry_change.is_code_entry {
-        fee /= CODE_ENTRY_RENT_DISCOUNT_FACTOR;
+        fee = num_integer::div_ceil(fee, CODE_ENTRY_RENT_DISCOUNT_FACTOR);
     }
     fee
 }

soroban-env-host/tests/fees.rs

@@ -547,9 +547,9 @@ fn test_rent_extend_fees_with_only_extend() {
             &fee_config,
             50_000,
         ),
-        // Rent: ceil(10 * 1024 * 1000 * 200_000 / (10_000 * 1024)) / 3 (=66_666)
+        // Rent: ceil(10 * 1024 * 1000 * 200_000 / (10_000 * 1024)) / 3 (=66_667)
         // Expiration entry write entry/bytes: 34
-        66_666 + 34
+        66_667 + 34
     );
 
     // Size decrease
@@ -654,10 +654,10 @@ fn test_rent_extend_fees_with_only_extend() {
             &fee_config,
             50_000,
         ),
-        // Rent: 20_000 + 200_000 + 66_666 + 1 + 20 + 200_000 + 20_000 (=506_687) +
+        // Rent: 20_000 + 200_000 + 66_667 + 1 + 20 + 200_000 + 20_000 (=506_688) +
         // Expiration entry write bytes: ceil(7 * 500 * 48 / 1024) (=165) +
         // Expiration entry write: 10 * 7
-        506_687 + 165 + 70
+        506_688 + 165 + 70
     );
 }
 
@@ -704,7 +704,7 @@ fn test_rent_extend_fees_with_only_size_change() {
             25_000,
         ),
         // 99_999 * 1000 * (100_000 - 25_000 + 1) / (10_000 * 1024) / 3
-        732_425 / 3
+        num_integer::div_ceil(732_425, 3)
     );
 
     // Large size increase, temp storage
@@ -794,7 +794,7 @@ fn test_rent_extend_fees_with_only_size_change() {
             25_000,
         ),
         // 732_425 + 732_425 / 3 + 73_243
-        1_049_809
+        1_049_810
     );
 }
 
@@ -845,7 +845,7 @@ fn test_rent_extend_with_size_change_and_extend() {
         // Rent: 100_000 * 1000 * 200_000 / (10_000 * 1024) / 2 +
         // 99_999 * 1000 * (100_000 - 25_000 + 1) / (10_000 * 1024)
         // Expiration entry write entry/bytes: 34
-        2_685_550 / 3 + 34
+        num_integer::div_ceil(2_685_550, 3) + 34
     );
 
     // Temp entry
@@ -903,7 +903,7 @@ fn test_rent_extend_with_size_change_and_extend() {
         // Rent: 2_685_550 + 2_685_550 / 3 + 268_556
         // Expiration entry write bytes: ceil(3 * 500 * 48 / 1024) (=71) +
         // Expiration entry write: 10 * 3
-        3_849_289 + 71 + 30
+        3_849_290 + 71 + 30
     );
 
     // Small increments

soroban-simulation/src/test/simulation.rs

@@ -146,7 +146,7 @@ fn test_simulate_upload_wasm() {
                 disk_read_bytes: 0,
                 write_bytes: expected_write_bytes,
             },
-            resource_fee: 4714773,
+            resource_fee: 4714774,
         })
     );
     assert_eq!(res.simulated_instructions, expected_instructions);
@@ -200,7 +200,7 @@ fn test_simulate_upload_wasm() {
                 disk_read_bytes: 0,
                 write_bytes: expected_write_bytes + 300,
             },
-            resource_fee: 7071426,
+            resource_fee: 7071427,
         })
     );
 }
@@ -589,7 +589,7 @@ fn test_simulate_invoke_contract_with_autorestore() {
                 disk_read_bytes: wasm_entry_size + contract_1_size,
                 write_bytes: wasm_entry_size + contract_1_size,
             },
-            resource_fee: 6231402,
+            resource_fee: 6231403,
         })
     );
     assert_eq!(res.simulated_instructions, expected_instructions);
@@ -704,7 +704,7 @@ fn test_simulate_extend_ttl_op() {
                     disk_read_bytes: 0,
                     write_bytes: 0,
                 },
-                resource_fee: 6204121,
+                resource_fee: 6204123,
             }
         }
     );
@@ -732,7 +732,7 @@ fn test_simulate_extend_ttl_op() {
                     disk_read_bytes: 0,
                     write_bytes: 0,
                 },
-                resource_fee: 104563088,
+                resource_fee: 104563090,
             }
         }
     );
@@ -777,7 +777,7 @@ fn test_simulate_extend_ttl_op() {
                     disk_read_bytes: 0,
                     write_bytes: 0,
                 },
-                resource_fee: 156844607,
+                resource_fee: 156844610,
             }
         }
     );
@@ -878,7 +878,7 @@ fn test_simulate_restore_op() {
                     disk_read_bytes: expected_rw_bytes,
                     write_bytes: expected_rw_bytes,
                 },
-                resource_fee: 10922801,
+                resource_fee: 10922803,
             }
         }
     );
@@ -907,7 +907,7 @@ fn test_simulate_restore_op() {
                     disk_read_bytes: expected_rw_bytes,
                     write_bytes: expected_rw_bytes,
                 },
-                resource_fee: 11130765,
+                resource_fee: 11130768,
             }
         }
     );
@@ -935,7 +935,7 @@ fn test_simulate_restore_op() {
                     disk_read_bytes: (expected_rw_bytes as f64 * 1.2) as u32,
                     write_bytes: (expected_rw_bytes as f64 * 1.3) as u32,
                 },
-                resource_fee: 16695904,
+                resource_fee: 16695909,
             }
         }
     );

soroban-simulation/src/test/snapshot_source.rs

@@ -169,7 +169,7 @@ fn test_automatic_restoration() {
                     disk_read_bytes: 112,
                     write_bytes: 112,
                 },
-                resource_fee: 23272,
+                resource_fee: 23274,
             }
         })
     );