From 5d8a32368a41c17bc5414355876377b5d32ba6f4 Mon Sep 17 00:00:00 2001
From: Jack Robison <jackrobison@lbry.io>
Date: Wed, 6 Apr 2022 22:01:55 -0400
Subject: [PATCH] add a migrator to build the hashX status index and to
 compactify histories

---
 scribe/blockchain/service.py       | 10 ++++
 scribe/db/db.py                    |  2 +-
 scribe/db/migrators/__init__.py    |  0
 scribe/db/migrators/migrate7to8.py | 89 ++++++++++++++++++++++++++++++
 4 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 scribe/db/migrators/__init__.py
 create mode 100644 scribe/db/migrators/migrate7to8.py

diff --git a/scribe/blockchain/service.py b/scribe/blockchain/service.py
index 8642505..b539ff0 100644
--- a/scribe/blockchain/service.py
+++ b/scribe/blockchain/service.py
@@ -1637,6 +1637,16 @@ class BlockchainProcessorService(BlockchainService):
         await self.run_in_thread_with_lock(flush)
 
     def _iter_start_tasks(self):
+        while self.db.db_version < max(self.db.DB_VERSIONS):
+            if self.db.db_version == 7:
+                from scribe.db.migrators.migrate7to8 import migrate, FROM_VERSION, TO_VERSION
+            else:
+                raise RuntimeError("unknown db version")
+            self.log.warning(f"migrating database from version {FROM_VERSION} to version {TO_VERSION}")
+            migrate(self.db)
+            self.log.info("finished migration")
+            self.db.read_db_state()
+
         self.height = self.db.db_height
         self.tip = self.db.db_tip
         self.tx_count = self.db.db_tx_count
diff --git a/scribe/db/db.py b/scribe/db/db.py
index 5587636..98fccae 100644
--- a/scribe/db/db.py
+++ b/scribe/db/db.py
@@ -32,7 +32,7 @@ TXO_STRUCT_pack = TXO_STRUCT.pack
 
 
 class HubDB:
-    DB_VERSIONS = HIST_DB_VERSIONS = [7]
+    DB_VERSIONS = [7, 8]
 
     def __init__(self, coin, db_dir: str, cache_MB: int = 512, reorg_limit: int = 200,
                  cache_all_claim_txos: bool = False, cache_all_tx_hashes: bool = False,
diff --git a/scribe/db/migrators/__init__.py b/scribe/db/migrators/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/scribe/db/migrators/migrate7to8.py b/scribe/db/migrators/migrate7to8.py
new file mode 100644
index 0000000..8a04d5d
--- /dev/null
+++ b/scribe/db/migrators/migrate7to8.py
@@ -0,0 +1,89 @@
+import logging
+import time
+import array
+import typing
+from bisect import bisect_right
+from scribe.common import sha256
+if typing.TYPE_CHECKING:
+    from scribe.db.db import HubDB
+
+FROM_VERSION = 7
+TO_VERSION = 8
+
+log = logging.getLogger()
+
+
+def get_all_hashXs(db):
+    def iterator():
+        last_hashX = None
+        for k in db.prefix_db.hashX_history.iterate(deserialize_key=False, include_value=False):
+            hashX = k[1:12]
+            if last_hashX is None:
+                last_hashX = hashX
+            if last_hashX != hashX:
+                yield hashX
+                last_hashX = hashX
+        if last_hashX:
+            yield last_hashX
+    return [hashX for hashX in iterator()]
+
+
+def hashX_history(db: 'HubDB', hashX: bytes):
+    history = b''
+    to_delete = []
+    for k, v in db.prefix_db.hashX_history.iterate(prefix=(hashX,), deserialize_value=False, deserialize_key=False):
+        to_delete.append((k, v))
+        history += v
+    return history, to_delete
+
+
+def hashX_status_from_history(db: 'HubDB', history: bytes) -> bytes:
+    tx_counts = db.tx_counts
+    hist_tx_nums = array.array('I')
+    hist_tx_nums.frombytes(history)
+    hist = ''
+    for tx_num in hist_tx_nums:
+        hist += f'{db.get_tx_hash(tx_num)[::-1].hex()}:{bisect_right(tx_counts, tx_num)}:'
+    return sha256(hist.encode())
+
+
+def migrate(db):
+    start = time.perf_counter()
+    prefix_db = db.prefix_db
+    hashXs = get_all_hashXs(db)
+    log.info(f"loaded {len(hashXs)} hashXs in {round(time.perf_counter() - start, 2)}s, "
+             f"now building the status index...")
+    op_cnt = 0
+    hashX_cnt = 0
+    for hashX in hashXs:
+        hashX_cnt += 1
+        key = prefix_db.hashX_status.pack_key(hashX)
+        history, to_delete = hashX_history(db, hashX)
+        status = hashX_status_from_history(db, history)
+        existing_status = prefix_db.hashX_status.get(hashX, deserialize_value=False)
+        if existing_status and existing_status != status:
+            prefix_db.stage_raw_delete(key, existing_status)
+            op_cnt += 1
+        elif existing_status == status:
+            pass
+        else:
+            prefix_db.stage_raw_put(key, status)
+            op_cnt += 1
+        if len(to_delete) > 1:
+            for k, v in to_delete:
+                prefix_db.stage_raw_delete(k, v)
+                op_cnt += 1
+            if history:
+                prefix_db.stage_raw_put(prefix_db.hashX_history.pack_key(hashX, 0), history)
+                op_cnt += 1
+        if op_cnt > 100000:
+            prefix_db.unsafe_commit()
+            log.info(f"wrote {hashX_cnt}/{len(hashXs)} hashXs statuses")
+            op_cnt = 0
+    if op_cnt:
+        prefix_db.unsafe_commit()
+        log.info(f"wrote {hashX_cnt}/{len(hashXs)} hashXs statuses")
+    db.db_version = 8
+    db.write_db_state()
+    db.prefix_db.unsafe_commit()
+    log.info("finished migration")