Merge bitcoin/bitcoin#22378: test: remove confusing `MAX_BLOCK_BASE_SIZE`

607076d01bf23c69ac21950c17b01fb4e1130774 test: remove confusing `MAX_BLOCK_BASE_SIZE` (Sebastian Falbesoner)
4af97c74edcda56cd15523bf3a335adea2bad14a test: introduce `get_weight()` helper for CBlock (Sebastian Falbesoner)
a084ebe1330bcec15715e08b0f65319142927ad1 test: introduce `get_weight()` helper for CTransaction (Sebastian Falbesoner)

Pull request description:

  This is a very late follow-up PR to #10618, which removed the constant `MAX_BLOCK_BASE_SIZE` from the core implementation about four years ago (see also #10608 in why it was considered confusing and superfluous).
  Since there is also no point in still keeping it in the functional test framework, the PR switches to weight-based accounting on the relevant test code parts and use `MAX_BLOCK_WEIGHT` instead for the block limit checks. To prepare that, the first two commits introduce `get_weight()` helpers for the classes CTransaction and CBlock, respectively.

ACKs for top commit:
  MarcoFalke:
    review ACK 607076d01bf23c69ac21950c17b01fb4e1130774 🚴

Tree-SHA512: d59aa0b6b3dfd0a849b8063e66de275d252f705f99e25cd3bf6daec028b47d946777ee5b42a060f5283cb18e917ac073119c2c0e11bbc21211f69ef0a6ed335a

1 files changed, 20 insertions, 20 deletions

diff --git a/test/functional/feature_block.py b/test/functional/feature_block.py
index c11eabc917..227be16487 100755
--- a/test/functional/feature_block.py
+++ b/test/functional/feature_block.py
@@ -22,7 +22,7 @@ from test_framework.messages import (
     CTransaction,
     CTxIn,
     CTxOut,
-    MAX_BLOCK_BASE_SIZE,
+    MAX_BLOCK_WEIGHT,
     uint256_from_compact,
     uint256_from_str,
 )
@@ -307,33 +307,33 @@ class FullBlockTest(BitcoinTestFramework):
         b22 = self.next_block(22, spend=out[5])
         self.send_blocks([b22], success=False, reject_reason='bad-txns-premature-spend-of-coinbase', reconnect=True)
 
-        # Create a block on either side of MAX_BLOCK_BASE_SIZE and make sure its accepted/rejected
+        # Create a block on either side of MAX_BLOCK_WEIGHT and make sure its accepted/rejected
         #     genesis -> b1 (0) -> b2 (1) -> b5 (2) -> b6  (3)
         #                                          \-> b12 (3) -> b13 (4) -> b15 (5) -> b23 (6)
         #                                                                           \-> b24 (6) -> b25 (7)
         #                      \-> b3 (1) -> b4 (2)
-        self.log.info("Accept a block of size MAX_BLOCK_BASE_SIZE")
+        self.log.info("Accept a block of weight MAX_BLOCK_WEIGHT")
         self.move_tip(15)
         b23 = self.next_block(23, spend=out[6])
         tx = CTransaction()
-        script_length = MAX_BLOCK_BASE_SIZE - len(b23.serialize()) - 69
+        script_length = (MAX_BLOCK_WEIGHT - b23.get_weight() - 276) // 4
         script_output = CScript([b'\x00' * script_length])
         tx.vout.append(CTxOut(0, script_output))
         tx.vin.append(CTxIn(COutPoint(b23.vtx[1].sha256, 0)))
         b23 = self.update_block(23, [tx])
-        # Make sure the math above worked out to produce a max-sized block
-        assert_equal(len(b23.serialize()), MAX_BLOCK_BASE_SIZE)
+        # Make sure the math above worked out to produce a max-weighted block
+        assert_equal(b23.get_weight(), MAX_BLOCK_WEIGHT)
         self.send_blocks([b23], True)
         self.save_spendable_output()
 
-        self.log.info("Reject a block of size MAX_BLOCK_BASE_SIZE + 1")
+        self.log.info("Reject a block of weight MAX_BLOCK_WEIGHT + 4")
         self.move_tip(15)
         b24 = self.next_block(24, spend=out[6])
-        script_length = MAX_BLOCK_BASE_SIZE - len(b24.serialize()) - 69
+        script_length = (MAX_BLOCK_WEIGHT - b24.get_weight() - 276) // 4
         script_output = CScript([b'\x00' * (script_length + 1)])
         tx.vout = [CTxOut(0, script_output)]
         b24 = self.update_block(24, [tx])
-        assert_equal(len(b24.serialize()), MAX_BLOCK_BASE_SIZE + 1)
+        assert_equal(b24.get_weight(), MAX_BLOCK_WEIGHT + 1 * 4)
         self.send_blocks([b24], success=False, reject_reason='bad-blk-length', reconnect=True)
 
         b25 = self.next_block(25, spend=out[7])
@@ -484,13 +484,13 @@ class FullBlockTest(BitcoinTestFramework):
         # Until block is full, add tx's with 1 satoshi to p2sh_script, the rest to OP_TRUE
         tx_new = None
         tx_last = tx
-        total_size = len(b39.serialize())
-        while(total_size < MAX_BLOCK_BASE_SIZE):
+        total_weight = b39.get_weight()
+        while total_weight < MAX_BLOCK_WEIGHT:
             tx_new = self.create_tx(tx_last, 1, 1, p2sh_script)
             tx_new.vout.append(CTxOut(tx_last.vout[1].nValue - 1, CScript([OP_TRUE])))
             tx_new.rehash()
-            total_size += len(tx_new.serialize())
-            if total_size >= MAX_BLOCK_BASE_SIZE:
+            total_weight += tx_new.get_weight()
+            if total_weight >= MAX_BLOCK_WEIGHT:
                 break
             b39.vtx.append(tx_new)  # add tx to block
             tx_last = tx_new
@@ -501,7 +501,7 @@ class FullBlockTest(BitcoinTestFramework):
         # Make sure we didn't accidentally make too big a block. Note that the
         # size of the block has non-determinism due to the ECDSA signature in
         # the first transaction.
-        while (len(b39.serialize()) >= MAX_BLOCK_BASE_SIZE):
+        while b39.get_weight() >= MAX_BLOCK_WEIGHT:
             del b39.vtx[-1]
 
         b39 = self.update_block(39, [])
@@ -891,7 +891,7 @@ class FullBlockTest(BitcoinTestFramework):
         self.send_blocks([b63], success=False, reject_reason='bad-txns-nonfinal', reconnect=True)
 
         #  This checks that a block with a bloated VARINT between the block_header and the array of tx such that
-        #  the block is > MAX_BLOCK_BASE_SIZE with the bloated varint, but <= MAX_BLOCK_BASE_SIZE without the bloated varint,
+        #  the block is > MAX_BLOCK_WEIGHT with the bloated varint, but <= MAX_BLOCK_WEIGHT without the bloated varint,
         #  does not cause a subsequent, identical block with canonical encoding to be rejected.  The test does not
         #  care whether the bloated block is accepted or rejected; it only cares that the second block is accepted.
         #
@@ -916,12 +916,12 @@ class FullBlockTest(BitcoinTestFramework):
         tx = CTransaction()
 
         # use canonical serialization to calculate size
-        script_length = MAX_BLOCK_BASE_SIZE - len(b64a.normal_serialize()) - 69
+        script_length = (MAX_BLOCK_WEIGHT - 4 * len(b64a.normal_serialize()) - 276) // 4
         script_output = CScript([b'\x00' * script_length])
         tx.vout.append(CTxOut(0, script_output))
         tx.vin.append(CTxIn(COutPoint(b64a.vtx[1].sha256, 0)))
         b64a = self.update_block("64a", [tx])
-        assert_equal(len(b64a.serialize()), MAX_BLOCK_BASE_SIZE + 8)
+        assert_equal(b64a.get_weight(), MAX_BLOCK_WEIGHT + 8 * 4)
         self.send_blocks([b64a], success=False, reject_reason='non-canonical ReadCompactSize()')
 
         # bitcoind doesn't disconnect us for sending a bloated block, but if we subsequently
@@ -935,7 +935,7 @@ class FullBlockTest(BitcoinTestFramework):
         b64 = CBlock(b64a)
         b64.vtx = copy.deepcopy(b64a.vtx)
         assert_equal(b64.hash, b64a.hash)
-        assert_equal(len(b64.serialize()), MAX_BLOCK_BASE_SIZE)
+        assert_equal(b64.get_weight(), MAX_BLOCK_WEIGHT)
         self.blocks[64] = b64
         b64 = self.update_block(64, [])
         self.send_blocks([b64], True)
@@ -1269,12 +1269,12 @@ class FullBlockTest(BitcoinTestFramework):
         for i in range(89, LARGE_REORG_SIZE + 89):
             b = self.next_block(i, spend)
             tx = CTransaction()
-            script_length = MAX_BLOCK_BASE_SIZE - len(b.serialize()) - 69
+            script_length = (MAX_BLOCK_WEIGHT - b.get_weight() - 276) // 4
             script_output = CScript([b'\x00' * script_length])
             tx.vout.append(CTxOut(0, script_output))
             tx.vin.append(CTxIn(COutPoint(b.vtx[1].sha256, 0)))
             b = self.update_block(i, [tx])
-            assert_equal(len(b.serialize()), MAX_BLOCK_BASE_SIZE)
+            assert_equal(b.get_weight(), MAX_BLOCK_WEIGHT)
             blocks.append(b)
             self.save_spendable_output()
             spend = self.get_spendable_output()