From 52791f111e9ee885389377a91cab44faa61c32b5 Mon Sep 17 00:00:00 2001
From: Michaël Ball <michael.ball@gmail.com>
Date: Fri, 27 Nov 2015 19:24:36 +0000
Subject: Better library management

---
 db/db_manager.py | 85 ++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 71 insertions(+), 14 deletions(-)

(limited to 'db/db_manager.py')

diff --git a/db/db_manager.py b/db/db_manager.py
index ca47ae4..82168d0 100644
--- a/db/db_manager.py
+++ b/db/db_manager.py
@@ -1,7 +1,7 @@
 import configparser
 import os
-
-import apsw
+import sqlite3
+import tempfile
 
 
 class DbManager:
@@ -9,6 +9,57 @@ class DbManager:
         config = configparser.ConfigParser()
         config.read("mach2.ini")
 
+        def iterdump(connection):
+            cu = connection.cursor()
+            yield("BEGIN TRANSACTION;")
+
+            q = """
+                SELECT "name", "type", "sql"
+                FROM "sqlite_master"
+                    WHERE "sql" NOT NULL AND
+                    "type" == 'table'
+                    ORDER BY "name";
+                """
+            schema_res = cu.execute(q).fetchall()
+            for table_name, type, sql in schema_res:
+                if table_name == "sqlite_sequence":
+                    yield("DELETE FROM \"sqlite_sequence\";")
+                elif table_name == "sqlite_stat1":
+                    yield("ANALYZE \"sqlite_master\";")
+                elif table_name.startswith("sqlite_"):
+                    continue
+                else:
+                    yield("{0};".format(sql))
+
+                table_name_ident = table_name.replace("\"", "\"\"")
+                res = cu.execute(
+                    "PRAGMA table_info(\"{0}\")".format(table_name_ident))
+                column_names = [
+                    str(table_info[1]) for table_info in res.fetchall()]
+                q = """
+                    SELECT 'INSERT INTO "{0}" VALUES({1})' FROM "{0}";
+                    """.format(
+                        table_name_ident,
+                        ",".join(
+                            """'||quote("{0}")||'""".format(
+                                col.replace(
+                                    "\"", "\"\"")) for col in column_names))
+                query_res = cu.execute(q)
+                for row in query_res:
+                    yield("{0};".format(row[0]))
+
+            q = """
+                SELECT "name", "type", "sql"
+                FROM "sqlite_master"
+                    WHERE "sql" NOT NULL AND
+                    "type" IN ('index', 'trigger', 'view')
+                """
+            schema_res = cu.execute(q)
+            for name, type, sql in schema_res.fetchall():
+                yield("{0};".format(sql))
+
+            yield("COMMIT;")
+
         def __init__(self):
             new_db = False
             cache_size_kb = 9766
@@ -17,31 +68,40 @@ class DbManager:
                 new_db = True
 
             if new_db:
-                self.conn = apsw.Connection(":memory:")
+                self.conn = sqlite3.connect(":memory:")
                 self.create_tables()
             else:
-                self.conn = apsw.Connection(self.config["DEFAULT"]["database"])
+                self.conn = sqlite3.connect(self.config["DEFAULT"]["database"])
                 library_info = os.stat(self.config["DEFAULT"]["database"])
                 cache_size_kb = round((library_info.st_size * 1.2) / 1024)
 
                 cursor = self.conn.cursor()
-                # Setting pragma with ? placeholder errors out
+                # Setting pragma with ? placeholder produces an error
                 cursor.execute("pragma cache_size=-%s" % cache_size_kb)
                 cursor.close()
 
+            self.conn.row_factory = sqlite3.Row
+
         def __del__(self):
             if not os.path.isfile(self.config["DEFAULT"]["database"]):
-                tempconn = apsw.Connection(self.config["DEFAULT"]["database"],
-                                           apsw.SQLITE_OPEN_READWRITE |
-                                           apsw.SQLITE_OPEN_CREATE)
+                script = ""
+
+                for line in DbManager.__DbManager.iterdump(self.conn):
+                    script = "\n".join((script, line))
 
-                with tempconn.backup("main", 
-                                     self.conn, "main") as backup:
-                    backup.step()
+                tempconn = sqlite3.connect(
+                    self.config["DEFAULT"]["database"])
+                tempcur = tempconn.cursor()
+
+                tempcur.executescript(script)
+                tempcur.close()
 
         def __str__(self):
             return repr(self)
 
+        def commit(self):
+            return self.conn.commit()
+
         def cursor(self):
             return self.conn.cursor()
 
@@ -51,9 +111,6 @@ class DbManager:
         def interrupt(self):
             return self.conn.interrupt()
 
-        def last_insert_rowid(self):
-            return self.conn.last_insert_rowid()
-
         def create_tables(self):
             cursor = self.conn.cursor()
             cursor.execute("""CREATE TABLE IF NOT EXISTS album (id
-- 
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