Merge bitcoin/bitcoin#29553: assumeutxo: Add dumptxoutset height param, remove shell scripts

94b0adcc37 rpc, refactor: Prevent potential race conditions in dumptxoutset (Fabian Jahr)
e868a6e070 doc: Improve assumeutxo guide and add more docs/comments (Fabian Jahr)
b29c21fc92 assumeutxo: Remove devtools/utxo_snapshot.sh (Fabian Jahr)
20a1c77aa7 contrib: Remove test_utxo_snapshots.sh (Fabian Jahr)
8426850352 test: Test for dumptxoutset at specific height (Fabian Jahr)
993cafe7e4 RPC: Add type parameter to dumptxoutset (Fabian Jahr)
fccf4f91d2 RPC: Extract ReconsiderBlock helper (Fabian Jahr)
446ce51c21 RPC: Extract InvalidateBlock helper (Fabian Jahr)

Pull request description:

  This adds a height parameter to the `dumptxoutset` RPC. This internalizes the workflow that was previously done by scripts: roll back the chain to the height we actually want the snapshot from, create the snapshot, roll forward to the real tip again.

  The nice thing about internalizing this functionality is that we can write tests for the code and it gives us more options to make the functionality robust. The shell scripts we have so far will be more cumbersome to maintain in the long run, especially since we will only notice later when we have broken them. I think it's safe to remove these `test_utxo_snapshots.sh` as well when we have this option in `dumptxoutset` because we have also added some good additional functional test coverage for this functionality.

ACKs for top commit:
  Sjors:
    re-utACK 94b0adcc37
  achow101:
    ACK 94b0adcc37
  mzumsande:
    ACK 94b0adcc37
  pablomartin4btc:
    re-ACK 94b0adcc37

Tree-SHA512: a4c9af5f687d1ca7bfb579a36f363882823386b5fa80c05de531b05a2782b5da6ff5baf3ada4bca8f32f63975d86f1948175abed9affe51fc958472b5f838dab

test/functional/feature_assumeutxo.py

@@ -22,6 +22,7 @@ from test_framework.util import (
     assert_approx,
     assert_equal,
     assert_raises_rpc_error,
+    sha256sum_file,
 )
 from test_framework.wallet import (
     getnewdestination,
@@ -295,7 +296,7 @@ class AssumeutxoTest(BitcoinTestFramework):
         assert_equal(n1.getblockcount(), START_HEIGHT)
 
         self.log.info(f"Creating a UTXO snapshot at height {SNAPSHOT_BASE_HEIGHT}")
-        dump_output = n0.dumptxoutset('utxos.dat')
+        dump_output = n0.dumptxoutset('utxos.dat', "latest")
 
         self.log.info("Test loading snapshot when the node tip is on the same block as the snapshot")
         assert_equal(n0.getblockcount(), SNAPSHOT_BASE_HEIGHT)
@@ -320,12 +321,16 @@ class AssumeutxoTest(BitcoinTestFramework):
         for n in self.nodes:
             assert_equal(n.getblockchaininfo()["headers"], SNAPSHOT_BASE_HEIGHT)
 
-        assert_equal(
-            dump_output['txoutset_hash'],
-            "a4bf3407ccb2cc0145c49ebba8fa91199f8a3903daf0883875941497d2493c27")
-        assert_equal(dump_output["nchaintx"], blocks[SNAPSHOT_BASE_HEIGHT].chain_tx)
         assert_equal(n0.getblockchaininfo()["blocks"], SNAPSHOT_BASE_HEIGHT)
 
+        def check_dump_output(output):
+            assert_equal(
+                output['txoutset_hash'],
+                "a4bf3407ccb2cc0145c49ebba8fa91199f8a3903daf0883875941497d2493c27")
+            assert_equal(output["nchaintx"], blocks[SNAPSHOT_BASE_HEIGHT].chain_tx)
+
+        check_dump_output(dump_output)
+
         # Mine more blocks on top of the snapshot that n1 hasn't yet seen. This
         # will allow us to test n1's sync-to-tip on top of a snapshot.
         self.generate(n0, nblocks=100, sync_fun=self.no_op)
@@ -335,6 +340,39 @@ class AssumeutxoTest(BitcoinTestFramework):
 
         assert_equal(n0.getblockchaininfo()["blocks"], FINAL_HEIGHT)
 
+        self.log.info(f"Check that dumptxoutset works for past block heights")
+        # rollback defaults to the snapshot base height
+        dump_output2 = n0.dumptxoutset('utxos2.dat', "rollback")
+        check_dump_output(dump_output2)
+        assert_equal(sha256sum_file(dump_output['path']), sha256sum_file(dump_output2['path']))
+
+        # Rollback with specific height
+        dump_output3 = n0.dumptxoutset('utxos3.dat', rollback=SNAPSHOT_BASE_HEIGHT)
+        check_dump_output(dump_output3)
+        assert_equal(sha256sum_file(dump_output['path']), sha256sum_file(dump_output3['path']))
+
+        # Specified height that is not a snapshot height
+        prev_snap_height = SNAPSHOT_BASE_HEIGHT - 1
+        dump_output4 = n0.dumptxoutset(path='utxos4.dat', rollback=prev_snap_height)
+        assert_equal(
+            dump_output4['txoutset_hash'],
+            "8a1db0d6e958ce0d7c963bc6fc91ead596c027129bacec68acc40351037b09d7")
+        assert sha256sum_file(dump_output['path']) != sha256sum_file(dump_output4['path'])
+
+        # Use a hash instead of a height
+        prev_snap_hash = n0.getblockhash(prev_snap_height)
+        dump_output5 = n0.dumptxoutset('utxos5.dat', rollback=prev_snap_hash)
+        assert_equal(sha256sum_file(dump_output4['path']), sha256sum_file(dump_output5['path']))
+
+        # TODO: This is a hack to set m_best_header to the correct value after
+        # dumptxoutset/reconsiderblock. Otherwise the wrong error messages are
+        # returned in following tests. It can be removed once this bug is
+        # fixed. See also https://github.com/bitcoin/bitcoin/issues/26245
+        self.restart_node(0, ["-reindex"])
+
+        # Ensure n0 is back at the tip
+        assert_equal(n0.getblockchaininfo()["blocks"], FINAL_HEIGHT)
+
         self.test_snapshot_with_less_work(dump_output['path'])
         self.test_invalid_mempool_state(dump_output['path'])
         self.test_invalid_snapshot_scenarios(dump_output['path'])

test/functional/rpc_dumptxoutset.py

@@ -27,7 +27,7 @@ class DumptxoutsetTest(BitcoinTestFramework):
         self.generate(node, COINBASE_MATURITY)
 
         FILENAME = 'txoutset.dat'
-        out = node.dumptxoutset(FILENAME)
+        out = node.dumptxoutset(FILENAME, "latest")
         expected_path = node.datadir_path / self.chain / FILENAME
 
         assert expected_path.is_file()
@@ -51,10 +51,14 @@ class DumptxoutsetTest(BitcoinTestFramework):
 
         # Specifying a path to an existing or invalid file will fail.
         assert_raises_rpc_error(
-            -8, '{} already exists'.format(FILENAME),  node.dumptxoutset, FILENAME)
+            -8, '{} already exists'.format(FILENAME),  node.dumptxoutset, FILENAME, "latest")
         invalid_path = node.datadir_path / "invalid" / "path"
         assert_raises_rpc_error(
-            -8, "Couldn't open file {}.incomplete for writing".format(invalid_path), node.dumptxoutset, invalid_path)
+            -8, "Couldn't open file {}.incomplete for writing".format(invalid_path), node.dumptxoutset, invalid_path, "latest")
+
+        self.log.info(f"Test that dumptxoutset with unknown dump type fails")
+        assert_raises_rpc_error(
+            -8, 'Invalid snapshot type "bogus" specified. Please specify "rollback" or "latest"', node.dumptxoutset, 'utxos.dat', "bogus")
 
 
 if __name__ == '__main__':

test/functional/wallet_assumeutxo.py

@@ -93,7 +93,7 @@ class AssumeutxoTest(BitcoinTestFramework):
 
         self.log.info(
             f"Creating a UTXO snapshot at height {SNAPSHOT_BASE_HEIGHT}")
-        dump_output = n0.dumptxoutset('utxos.dat')
+        dump_output = n0.dumptxoutset('utxos.dat', "latest")
 
         assert_equal(
             dump_output['txoutset_hash'],