Alter some identifiers. #207
[zzz-pokedex.git] / pokedex / db / load.py
index 1cff39d..f0e4b6d 100644 (file)
 """CSV to database or vice versa."""
 import csv
-import pkg_resources
+import fnmatch
+import os.path
 import sys
 
 from sqlalchemy.orm.attributes import instrumentation_registry
+import sqlalchemy.sql.util
 import sqlalchemy.types
 
 from pokedex.db import metadata
 import pokedex.db.tables as tables
+from pokedex.defaults import get_default_csv_dir
 
 
-def load(session, directory=None, drop_tables=False):
+def _get_table_names(metadata, patterns):
+    """Returns a list of table names from the given metadata.  If `patterns`
+    exists, only tables matching one of the patterns will be returned.
+    """
+    if patterns:
+        table_names = set()
+        for pattern in patterns:
+            if '.' in pattern or '/' in pattern:
+                # If it looks like a filename, pull out just the table name
+                _, filename = os.path.split(pattern)
+                table_name, _ = os.path.splitext(filename)
+                pattern = table_name
+
+            table_names.update(fnmatch.filter(metadata.tables.keys(), pattern))
+    else:
+        table_names = metadata.tables.keys()
+
+    return list(table_names)
+
+def _get_verbose_prints(verbose):
+    """If `verbose` is true, returns three functions: one for printing a
+    starting message, one for printing an interim status update, and one for
+    printing a success or failure message when finished.
+
+    If `verbose` is false, returns no-op functions.
+    """
+
+    if not verbose:
+        # Return dummies
+        def dummy(*args, **kwargs):
+            pass
+
+        return dummy, dummy, dummy
+
+    ### Okay, verbose == True; print stuff
+
+    def print_start(thing):
+        # Truncate to 66 characters, leaving 10 characters for a success
+        # or failure message
+        truncated_thing = thing[0:66]
+
+        # Also, space-pad to keep the cursor in a known column
+        num_spaces = 66 - len(truncated_thing)
+
+        print "%s...%s" % (truncated_thing, ' ' * num_spaces),
+        sys.stdout.flush()
+
+    if sys.stdout.isatty():
+        # stdout is a terminal; stupid backspace tricks are OK.
+        # Don't use print, because it always adds magical spaces, which
+        # makes backspace accounting harder
+
+        backspaces = [0]
+        def print_status(msg):
+            # Overwrite any status text with spaces before printing
+            sys.stdout.write('\b' * backspaces[0])
+            sys.stdout.write(' ' * backspaces[0])
+            sys.stdout.write('\b' * backspaces[0])
+            sys.stdout.write(msg)
+            sys.stdout.flush()
+            backspaces[0] = len(msg)
+
+        def print_done(msg='ok'):
+            # Overwrite any status text with spaces before printing
+            sys.stdout.write('\b' * backspaces[0])
+            sys.stdout.write(' ' * backspaces[0])
+            sys.stdout.write('\b' * backspaces[0])
+            sys.stdout.write(msg + "\n")
+            sys.stdout.flush()
+            backspaces[0] = 0
+
+    else:
+        # stdout is a file (or something); don't bother with status at all
+        def print_status(msg):
+            pass
+
+        def print_done(msg='ok'):
+            print msg
+
+    return print_start, print_status, print_done
+
+
+def load(session, tables=[], directory=None, drop_tables=False, verbose=False, safe=True):
     """Load data from CSV files into the given database session.
 
     Tables are created automatically.
@@ -18,66 +103,101 @@ def load(session, directory=None, drop_tables=False):
     `session`
         SQLAlchemy session to use.
 
+    `tables`
+        List of tables to load.  If omitted, all tables are loaded.
+
     `directory`
         Directory the CSV files reside in.  Defaults to the `pokedex` data
         directory.
 
     `drop_tables`
         If set to True, existing `pokedex`-related tables will be dropped.
-    """
 
-    if not directory:
-        directory = pkg_resources.resource_filename('pokedex', 'data/csv')
+    `verbose`
+        If set to True, status messages will be printed to stdout.
 
-    # Drop all tables if requested
-    if options.drop_tables:
-        print 'Dropping tables...'
-        metadata.drop_all()
+    `safe`
+        If set to False, load can be faster, but can corrupt the database if
+        it crashes or is interrupted.
+    """
 
-    metadata.create_all()
+    # First take care of verbosity
+    print_start, print_status, print_done = _get_verbose_prints(verbose)
 
-    # SQLAlchemy is retarded and there is no way for me to get a list of ORM
-    # classes besides to inspect the module they all happen to live in for
-    # things that look right.
-    table_base = tables.TableBase
-    orm_classes = {}  # table object => table class
 
-    for name in dir(tables):
-        # dir() returns strings!  How /convenient/.
-        thingy = getattr(tables, name)
+    if directory is None:
+        directory = get_default_csv_dir()
 
-        if not isinstance(thingy, type):
-            # Not a class; bail
-            continue
-        elif not issubclass(thingy, table_base):
-            # Not a declarative table; bail
-            continue
-        elif thingy == table_base:
-            # Declarative table base, so not a real table; bail
-            continue
+    table_names = _get_table_names(metadata, tables)
+    table_objs = [metadata.tables[name] for name in table_names]
+    table_objs = sqlalchemy.sql.util.sort_tables(table_objs)
 
-        # thingy is definitely a table class!  Hallelujah.
-        orm_classes[thingy.__table__] = thingy
+    # SQLite speed tweaks
+    if not safe and session.connection().dialect.name == 'sqlite':
+        session.connection().execute("PRAGMA synchronous=OFF")
+        session.connection().execute("PRAGMA journal_mode=OFF")
+
+    # Drop all tables if requested
+    if drop_tables:
+        print_start('Dropping tables')
+        for n, table in enumerate(reversed(table_objs)):
+            table.drop(checkfirst=True)
+            print_status('%s/%s' % (n, len(table_objs)))
+        print_done()
+
+    print_start('Creating tables')
+    for n, table in enumerate(table_objs):
+        table.create()
+        print_status('%s/%s' % (n, len(table_objs)))
+    print_done()
+    connection = session.connection()
 
     # Okay, run through the tables and actually load the data now
-    for table_obj in metadata.sorted_tables:
-        table_class = orm_classes[table_obj]
+    for table_obj in table_objs:
         table_name = table_obj.name
+        insert_stmt = table_obj.insert()
 
-        # Print the table name but leave the cursor in a fixed column
-        print table_name + '...', ' ' * (40 - len(table_name)),
-        sys.stdout.flush()
+        print_start(table_name)
 
         try:
-            csvfile = open("%s/%s.csv" % (directory, table_name), 'rb')
+            csvpath = "%s/%s.csv" % (directory, table_name)
+            csvfile = open(csvpath, 'rb')
         except IOError:
             # File doesn't exist; don't load anything!
-            print 'no data!'
+            print_done('missing?')
             continue
 
+        csvsize = os.stat(csvpath).st_size
+
         reader = csv.reader(csvfile, lineterminator='\n')
         column_names = [unicode(column) for column in reader.next()]
 
+        if not safe and session.connection().dialect.name == 'postgresql':
+            """
+            Postgres' CSV dialect works with our data, if we mark the not-null
+            columns with FORCE NOT NULL.
+            COPY is only allowed for DB superusers. If you're not one, use safe
+            loading (pokedex load -S).
+            """
+            session.commit()
+            not_null_cols = [c for c in column_names if not table_obj.c[c].nullable]
+            if not_null_cols:
+                force_not_null = 'FORCE NOT NULL ' + ','.join('"%s"' % c for c in not_null_cols)
+            else:
+                force_not_null = ''
+            command = "COPY %(table_name)s (%(columns)s) FROM '%(csvpath)s' CSV HEADER %(force_not_null)s"
+            session.connection().execute(
+                command % dict(
+                    table_name=table_name,
+                    csvpath=csvpath,
+                    columns=','.join('"%s"' % c for c in column_names),
+                    force_not_null=force_not_null,
+                )
+            )
+            session.commit()
+            print_done()
+            continue
+
         # Self-referential tables may contain rows with foreign keys of other
         # rows in the same table that do not yet exist.  Pull these out and add
         # them to the session last
@@ -91,8 +211,19 @@ def load(session, directory=None, drop_tables=False):
             if any(_.references(table_obj) for _ in column.foreign_keys):
                 self_ref_columns.append(column)
 
+        new_rows = []
+        def insert_and_commit():
+            if not new_rows:
+                return
+            session.connection().execute(insert_stmt, new_rows)
+            session.commit()
+            new_rows[:] = []
+
+            progress = "%d%%" % (100 * csvfile.tell() // csvsize)
+            print_status(progress)
+
         for csvs in reader:
-            row = table_class()
+            row_data = {}
 
             for column_name, value in zip(column_names, csvs):
                 column = table_obj.c[column_name]
@@ -110,66 +241,93 @@ def load(session, directory=None, drop_tables=False):
                     # Otherwise, unflatten from bytes
                     value = value.decode('utf-8')
 
-                setattr(row, column_name, value)
+                # nb: Dictionaries flattened with ** have to have string keys
+                row_data[ str(column_name) ] = value
 
             # May need to stash this row and add it later if it refers to a
             # later row in this table
             if self_ref_columns:
-                foreign_ids = [getattr(row, _.name) for _ in self_ref_columns]
+                foreign_ids = [row_data[_.name] for _ in self_ref_columns]
                 foreign_ids = [_ for _ in foreign_ids if _]  # remove NULL ids
 
                 if not foreign_ids:
                     # NULL key.  Remember this row and add as usual.
-                    seen_ids[row.id] = 1
+                    seen_ids[row_data['id']] = 1
 
                 elif all(_ in seen_ids for _ in foreign_ids):
                     # Non-NULL key we've already seen.  Remember it and commit
                     # so we know the old row exists when we add the new one
-                    session.commit()
-                    seen_ids[row.id] = 1
+                    insert_and_commit()
+                    seen_ids[row_data['id']] = 1
 
                 else:
                     # Non-NULL future id.  Save this and insert it later!
-                    deferred_rows.append((row, foreign_ids))
+                    deferred_rows.append((row_data, foreign_ids))
                     continue
 
-            session.add(row)
+            # Insert row!
+            new_rows.append(row_data)
 
-        session.commit()
+            # Remembering some zillion rows in the session consumes a lot of
+            # RAM.  Let's not do that.  Commit every 1000 rows
+            if len(new_rows) >= 1000:
+                insert_and_commit()
+
+        insert_and_commit()
 
         # Attempt to add any spare rows we've collected
-        for row, foreign_ids in deferred_rows:
+        for row_data, foreign_ids in deferred_rows:
             if not all(_ in seen_ids for _ in foreign_ids):
                 # Could happen if row A refers to B which refers to C.
                 # This is ridiculous and doesn't happen in my data so far
                 raise ValueError("Too many levels of self-reference!  "
-                                 "Row was: " + str(row.__dict__))
+                                 "Row was: " + str(row))
 
-            session.add(row)
-            seen_ids[row.id] = 1
-            session.commit()
+            session.connection().execute(
+                insert_stmt.values(**row_data)
+            )
+            seen_ids[row_data['id']] = 1
+        session.commit()
+
+        print_done()
 
-        print 'loaded'
+    # SQLite check
+    if session.connection().dialect.name == 'sqlite':
+        session.connection().execute("PRAGMA integrity_check")
 
 
 
-def dump(session, directory=None):
+def dump(session, tables=[], directory=None, verbose=False):
     """Dumps the contents of a database to a set of CSV files.  Probably not
     useful to anyone besides a developer.
 
     `session`
         SQLAlchemy session to use.
 
+    `tables`
+        List of tables to dump.  If omitted, all tables are dumped.
+
     `directory`
         Directory the CSV files should be put in.  Defaults to the `pokedex`
         data directory.
+
+    `verbose`
+        If set to True, status messages will be printed to stdout.
     """
 
+    # First take care of verbosity
+    print_start, print_status, print_done = _get_verbose_prints(verbose)
+
+
     if not directory:
-        directory = pkg_resources.resource_filename('pokedex', 'data/csv')
+        directory = get_default_csv_dir()
+
+    table_names = _get_table_names(metadata, tables)
+    table_names.sort()
 
-    for table_name in sorted(metadata.tables.keys()):
-        print table_name
+
+    for table_name in table_names:
+        print_start(table_name)
         table = metadata.tables[table_name]
 
         writer = csv.writer(open("%s/%s.csv" % (directory, table_name), 'wb'),
@@ -195,3 +353,5 @@ def dump(session, directory=None):
                 csvs.append(val)
 
             writer.writerow(csvs)
+
+        print_done()