Make pokedex work with SQLAlchemy 0.7. Warning: ugly hack!
[zzz-pokedex.git] / pokedex / db / load.py
index 2b14883..d0dc00b 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
+from pokedex.db.dependencies import find_dependent_tables
 
 
+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 two functions: one for printing a starting
-    message, and the other for printing a success or failure message when
-    finished.
+    """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 two no-op functions.
+    If `verbose` is false, returns no-op functions.
     """
 
-    if verbose:
-        import sys
-        def print_start(thing):
-            # Truncate to 66 characters, leaving 10 characters for a success
-            # or failure message
-            truncated_thing = thing[0:66]
+    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[:66]
+
+        # Also, space-pad to keep the cursor in a known column
+        num_spaces = 66 - len(truncated_thing)
 
-            # 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()
 
-            print "%s...%s" % (truncated_thing, ' ' * num_spaces),
+    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'):
-            print 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 + "\n")
             sys.stdout.flush()
+            backspaces[0] = 0
 
-        return print_start, print_done
+    else:
+        # stdout is a file (or something); don't bother with status at all
+        def print_status(msg):
+            pass
 
-    # Not verbose; return dummies
-    def dummy(*args, **kwargs):
-        pass
+        def print_done(msg='ok'):
+            print msg
 
-    return dummy, dummy
+    return print_start, print_status, print_done
 
 
-def load(session, directory=None, drop_tables=False, verbose=False):
+def load(session, tables=[], directory=None, drop_tables=False, verbose=False, safe=True, recursive=False):
     """Load data from CSV files into the given database session.
 
     Tables are created automatically.
@@ -52,6 +103,9 @@ def load(session, directory=None, drop_tables=False, verbose=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.
@@ -61,60 +115,121 @@ def load(session, directory=None, drop_tables=False, verbose=False):
 
     `verbose`
         If set to True, status messages will be printed to stdout.
+
+    `safe`
+        If set to False, load can be faster, but can corrupt the database if
+        it crashes or is interrupted.
+
+    `recursive`
+        If set to True, load all dependent tables too.
     """
 
     # First take care of verbosity
-    print_start, print_done = _get_verbose_prints(verbose)
+    print_start, print_status, print_done = _get_verbose_prints(verbose)
 
 
-    if not directory:
-        directory = pkg_resources.resource_filename('pokedex', 'data/csv')
+    if directory is None:
+        directory = get_default_csv_dir()
+
+    # XXX why isn't this done in command_load
+    table_names = _get_table_names(metadata, tables)
+    table_objs = [metadata.tables[name] for name in table_names]
+
+    if recursive:
+        table_objs.extend(find_dependent_tables(table_objs))
+
+    table_objs = sqlalchemy.sql.util.sort_tables(table_objs)
+
+    # 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')
-        metadata.drop_all()
+        for n, table in enumerate(reversed(table_objs)):
+            table.drop(checkfirst=True)
+            print_status('%s/%s' % (n, len(table_objs)))
         print_done()
 
-    metadata.create_all()
+    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:
+    for table_obj in table_objs:
         table_name = table_obj.name
         insert_stmt = table_obj.insert()
 
         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_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
         # ASSUMPTION: Self-referential tables have a single PK called "id"
         deferred_rows = []  # ( row referring to id, [foreign ids we need] )
-        seen_ids = {}       # primary key we've seen => 1
+        seen_ids = set()    # primary keys we've seen
 
         # Fetch foreign key columns that point at this table, if any
         self_ref_columns = []
         for column in table_obj.c:
-            if any(_.references(table_obj) for _ in column.foreign_keys):
+            if any(x.references(table_obj) for x 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_data = {}
 
@@ -140,18 +255,18 @@ def load(session, directory=None, drop_tables=False, verbose=False):
             # 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 = [row_data[_.name] for _ in self_ref_columns]
-                foreign_ids = [_ for _ in foreign_ids if _]  # remove NULL ids
+                foreign_ids = set(row_data[x.name] for x in self_ref_columns)
+                foreign_ids.discard(None)  # remove NULL ids
 
                 if not foreign_ids:
                     # NULL key.  Remember this row and add as usual.
-                    seen_ids[row_data['id']] = 1
+                    seen_ids.add(row_data['id'])
 
-                elif all(_ in seen_ids for _ in foreign_ids):
+                elif foreign_ids.issubset(seen_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
                     insert_and_commit()
-                    seen_ids[row_data['id']] = 1
+                    seen_ids.add(row_data['id'])
 
                 else:
                     # Non-NULL future id.  Save this and insert it later!
@@ -163,14 +278,14 @@ def load(session, directory=None, drop_tables=False, verbose=False):
 
             # 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:
+            if len(new_rows) >= 1000:
                 insert_and_commit()
 
         insert_and_commit()
 
         # Attempt to add any spare rows we've collected
         for row_data, foreign_ids in deferred_rows:
-            if not all(_ in seen_ids for _ in foreign_ids):
+            if not foreign_ids.issubset(seen_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!  "
@@ -179,20 +294,27 @@ def load(session, directory=None, drop_tables=False, verbose=False):
             session.connection().execute(
                 insert_stmt.values(**row_data)
             )
-            seen_ids[row_data['id']] = 1
+            seen_ids.add(row_data['id'])
         session.commit()
 
         print_done()
 
+    # SQLite check
+    if session.connection().dialect.name == 'sqlite':
+        session.connection().execute("PRAGMA integrity_check")
 
 
-def dump(session, directory=None, verbose=False):
+
+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.
@@ -202,13 +324,17 @@ def dump(session, directory=None, verbose=False):
     """
 
     # First take care of verbosity
-    print_start, print_done = _get_verbose_prints(verbose)
+    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()):
+    for table_name in table_names:
         print_start(table_name)
         table = metadata.tables[table_name]