refactor: replace sqlite with rocksdb (#109)

* refactor: replace sqlite with rocksdb

* Potential fix for pull request finding 'Empty except'

Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>

* Update graphgen/models/storage/rocksdb_cache.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

---------

Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: 3 people

graphgen/models/__init__.py

@@ -33,5 +33,5 @@
 from .searcher.web.bing_search import BingSearch
 from .searcher.web.google_search import GoogleSearch
 from .splitter import ChineseRecursiveTextSplitter, RecursiveCharacterSplitter
-from .storage import JsonKVStorage, JsonListStorage, NetworkXStorage
+from .storage import JsonKVStorage, JsonListStorage, NetworkXStorage, RocksDBCache
 from .tokenizer import Tokenizer

graphgen/models/storage/__init__.py

@@ -1,2 +1,3 @@
 from .json_storage import JsonKVStorage, JsonListStorage
 from .networkx_storage import NetworkXStorage
+from .rocksdb_cache import RocksDBCache

graphgen/models/storage/rocksdb_cache.py

@@ -0,0 +1,43 @@
+from pathlib import Path
+from typing import Any, Iterator, Optional
+
+# rocksdict is a lightweight C wrapper around RocksDB for Python, pylint may not recognize it
+# pylint: disable=no-name-in-module
+from rocksdict import Rdict
+
+
+class RocksDBCache:
+    def __init__(self, cache_dir: str):
+        self.db_path = Path(cache_dir)
+        self.db = Rdict(str(self.db_path))
+
+    def get(self, key: str) -> Optional[Any]:
+        return self.db.get(key)
+
+    def set(self, key: str, value: Any):
+        self.db[key] = value
+
+    def delete(self, key: str):
+        try:
+            del self.db[key]
+        except KeyError:
+            # If the key does not exist, do nothing (deletion is idempotent for caches)
+            pass
+
+    def close(self):
+        if hasattr(self, "db") and self.db is not None:
+            self.db.close()
+            self.db = None
+
+    def __del__(self):
+        # Ensure the database is closed when the object is destroyed
+        self.close()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
+
+    def __iter__(self) -> Iterator[str]:
+        return iter(self.db.keys())

graphgen/operators/read/parallel_file_scanner.py

@@ -4,16 +4,15 @@
 from pathlib import Path
 from typing import Any, Dict, List, Set, Union
 
-from diskcache import Cache
-
+from graphgen.models import RocksDBCache
 from graphgen.utils import logger
 
 
 class ParallelFileScanner:
     def __init__(
         self, cache_dir: str, allowed_suffix, rescan: bool = False, max_workers: int = 4
     ):
-        self.cache = Cache(cache_dir)
+        self.cache = RocksDBCache(os.path.join(cache_dir, "file_paths_cache"))
         self.allowed_suffix = set(allowed_suffix) if allowed_suffix else None
         self.rescan = rescan
         self.max_workers = max_workers

requirements.txt

@@ -20,13 +20,15 @@ requests
 fastapi
 trafilatura
 aiohttp
-diskcache
 socksio
 
 leidenalg
 igraph
 python-louvain
 
+# storage
+rocksdict
+
 # KG
 rdflib