veekun_pokedex/pokedex/db/load.py

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"""CSV to database or vice versa."""
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from __future__ import print_function
import csv
import fnmatch
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import io
import os.path
import sys
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import six
import sqlalchemy.sql.util
import sqlalchemy.types
import pokedex
from pokedex.db import metadata, tables, translations
from pokedex.defaults import get_default_csv_dir
from pokedex.db.dependencies import find_dependent_tables
from pokedex.db.oracle import rewrite_long_table_names
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)
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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.
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If `verbose` is false, returns no-op functions.
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"""
if not verbose:
# Return dummies
def dummy(*args, **kwargs):
pass
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return dummy, dummy, dummy
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### 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)
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print("%s...%s" % (truncated_thing, ' ' * num_spaces), end='')
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)
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sys.stdout.flush()
backspaces[0] = len(msg)
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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")
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sys.stdout.flush()
backspaces[0] = 0
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else:
# stdout is a file (or something); don't bother with status at all
def print_status(msg):
pass
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def print_done(msg='ok'):
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print(msg)
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return print_start, print_status, print_done
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def load(session, tables=[], directory=None, drop_tables=False, verbose=False, safe=True, recursive=True, langs=None):
"""Load data from CSV files into the given database session.
Tables are created automatically.
`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.
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`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.
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`langs`
List of identifiers of extra language to load, or None to load them all
"""
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# First take care of verbosity
print_start, print_status, print_done = _get_verbose_prints(verbose)
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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)
engine = session.get_bind()
# Limit table names to 30 characters for Oracle
oracle = (engine.dialect.name == 'oracle')
if oracle:
rewrite_long_table_names()
# SQLite speed tweaks
if not safe and engine.dialect.name == 'sqlite':
session.execute("PRAGMA synchronous=OFF")
session.execute("PRAGMA journal_mode=OFF")
# Drop all tables if requested
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if drop_tables:
print_start('Dropping tables')
for n, table in enumerate(reversed(table_objs)):
table.drop(bind=engine, checkfirst=True)
# Drop columns' types if appropriate; needed for enums in
# postgresql
for column in table.c:
try:
drop = column.type.drop
except AttributeError:
pass
else:
drop(bind=engine, checkfirst=True)
print_status('%s/%s' % (n, len(table_objs)))
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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()
# Okay, run through the tables and actually load the data now
for table_obj in table_objs:
if oracle:
table_name = table_obj._original_name
else:
table_name = table_obj.name
insert_stmt = table_obj.insert()
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print_start(table_name)
try:
csvpath = "%s/%s.csv" % (directory, table_name)
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csvfile = open(csvpath, 'r')
except IOError:
# File doesn't exist; don't load anything!
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print_done('missing?')
continue
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# XXX This is wrong for files with multi-line fields, but Python 3
# doesn't allow .tell() on a file that's currently being iterated
# (because the result is completely bogus). Oh well.
csvsize = sum(1 for line in csvfile)
csvfile.seek(0)
reader = csv.reader(csvfile, lineterminator='\n')
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column_names = [six.text_type(column) for column in next(reader)]
if not safe and engine.dialect.name == 'postgresql':
# Postgres' CSV dialect works with our data, if we mark the not-null
# columns with FORCE NOT NULL.
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 = ''
# Grab the underlying psycopg2 cursor so we can use COPY FROM STDIN
raw_conn = engine.raw_connection()
command = "COPY %(table_name)s (%(columns)s) FROM STDIN CSV HEADER %(force_not_null)s"
csvfile.seek(0)
raw_conn.cursor().copy_expert(
command % dict(
table_name=table_name,
columns=','.join('"%s"' % c for c in column_names),
force_not_null=force_not_null,
),
csvfile,
)
raw_conn.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
# insert them last
# ASSUMPTION: Self-referential tables have a single PK called "id"
deferred_rows = [] # ( row referring to id, [foreign ids we need] )
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(x.references(table_obj) for x in column.foreign_keys):
self_ref_columns.append(column)
new_rows = []
def insert_and_commit():
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if not new_rows:
return
session.execute(insert_stmt, new_rows)
session.commit()
new_rows[:] = []
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progress = "%d%%" % (100 * csvpos // csvsize)
print_status(progress)
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csvpos = 0
for csvs in reader:
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csvpos += 1
row_data = {}
for column_name, value in zip(column_names, csvs):
column = table_obj.c[column_name]
if column.nullable and value == '':
# Empty string in a nullable column really means NULL
value = None
elif isinstance(column.type, sqlalchemy.types.Boolean):
# Boolean values are stored as string values 0/1, but both
# of those evaluate as true; SQLA wants True/False
if value == '0':
value = False
else:
value = True
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elif isinstance(value, bytes):
# Otherwise, unflatten from bytes
value = value.decode('utf-8')
# 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 = 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.add(row_data['id'])
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.add(row_data['id'])
else:
# Non-NULL future id. Save this and insert it later!
deferred_rows.append((row_data, foreign_ids))
continue
# Insert row!
new_rows.append(row_data)
# 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_data, foreign_ids in deferred_rows:
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! "
"Row was: " + str(row_data))
session.execute(
insert_stmt.values(**row_data)
)
seen_ids.add(row_data['id'])
session.commit()
print_done()
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print_start('Translations')
transl = translations.Translations(csv_directory=directory)
new_row_count = 0
for translation_class, rows in transl.get_load_data(langs):
table_obj = translation_class.__table__
if table_obj in table_objs:
insert_stmt = table_obj.insert()
session.execute(insert_stmt, rows)
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session.commit()
# We don't have a total, but at least show some increasing number
new_row_count += len(rows)
print_status(str(new_row_count))
# SQLite check
if engine.dialect.name == 'sqlite':
session.execute("PRAGMA integrity_check")
print_done()
def dump(session, tables=[], directory=None, verbose=False, langs=None):
"""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.
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`verbose`
If set to True, status messages will be printed to stdout.
`langs`
List of identifiers of languages to dump unofficial texts for
"""
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# First take care of verbosity
print_start, print_status, print_done = _get_verbose_prints(verbose)
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languages = dict((l.id, l) for l in session.query(pokedex.db.tables.Language))
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if not directory:
directory = get_default_csv_dir()
table_names = _get_table_names(metadata, tables)
table_names.sort()
# Oracle needs to dump from tables with shortened names to csvs with the
# usual names
oracle = (session.connection().dialect.name == 'oracle')
if oracle:
rewrite_long_table_names()
for table_name in table_names:
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print_start(table_name)
table = metadata.tables[table_name]
if oracle:
filename = '%s/%s.csv' % (directory, table._original_name)
else:
filename = '%s/%s.csv' % (directory, table_name)
# CSV module only works with bytes on 2 and only works with text on 3!
if six.PY3:
writer = csv.writer(open(filename, 'w', newline=''), lineterminator='\n')
columns = [col.name for col in table.columns]
else:
writer = csv.writer(open(filename, 'wb'), lineterminator='\n')
columns = [col.name.encode('utf8') for col in table.columns]
# For name tables, always dump rows for official languages, as well as
# for those in `langs` if specified.
# For other translation tables, only dump rows for languages in `langs`
# if specified, or for official languages by default.
# For non-translation tables, dump all rows.
if 'local_language_id' in columns:
if langs is None:
def include_row(row):
return languages[row.local_language_id].official
elif any(col.info.get('official') for col in table.columns):
def include_row(row):
return (languages[row.local_language_id].official or
languages[row.local_language_id].identifier in langs)
else:
def include_row(row):
return languages[row.local_language_id].identifier in langs
else:
def include_row(row):
return True
writer.writerow(columns)
primary_key = table.primary_key
for row in session.query(table).order_by(*primary_key).all():
if include_row(row):
csvs = []
for col in columns:
# Convert Pythony values to something more universal
val = getattr(row, col)
if val == None:
val = ''
elif val == True:
val = '1'
elif val == False:
val = '0'
else:
val = six.text_type(val)
if not six.PY3:
val = val.encode('utf8')
csvs.append(val)
writer.writerow(csvs)
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print_done()