initial commit

functions/cachedb.py

@@ -0,0 +1,55 @@
+"""Functions for cache DB for seafile mirror"""
+
+import json
+import logging
+from pathlib import Path
+
+
+def db_read(cachefile) -> dict:
+    """Get the cache database file as a dict"""
+    dbpath = Path(cachefile)
+
+    # If DB file exists, return JSON as dict
+    if dbpath.is_file():
+        with open(cachefile, "r", encoding="UTF-8") as dbread:
+            logging.debug("Reading cache file '%s' from disk", cachefile)
+            cachedb = json.load(dbread)
+    else:
+        logging.debug("Cache file '%s' does not exist on disk", cachefile)
+        cachedb = {}
+
+    # Add/Update key containing the local cache file so we can easily access it
+    cachedb["_cachefile"] = cachefile
+
+    return cachedb
+
+
+def db_write(dbdict):
+    """Update/create the cache database file with a dict"""
+    with open(dbdict["_cachefile"], "w", encoding="UTF-8") as dbwrite:
+        logging.debug("Writing cache file '%s' to disk", dbdict["_cachefile"])
+        json.dump(dbdict, dbwrite, indent=2)
+        # Append newline to file
+        dbwrite.write("\n")
+
+
+def db_update(dbdict, libid, **kwargs):
+    """Update the cached key/values for a specific library, and write the cache file"""
+    # Create dict entry for library if it doesn't exist yet
+    if libid not in dbdict:
+        dbdict[libid] = {}
+    for key, value in kwargs.items():
+        logging.debug(
+            "Updating '%s' of library '%s' in in-memory cache dictionary", key, libid
+        )
+        dbdict[libid][key] = value
+
+    db_write(dbdict)
+
+
+def db_get_library_key(dbdict, libid, key):
+    """Get value of requested key from the cache dictionary"""
+    if libid in dbdict and key in dbdict[libid]:
+        return dbdict[libid][key]
+
+    return None