-
-
Notifications
You must be signed in to change notification settings - Fork 671
/
database.py
492 lines (433 loc) · 16.3 KB
/
database.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
import asyncio
from collections import namedtuple
from pathlib import Path
import janus
import queue
import sys
import threading
import uuid
from .tracer import trace
from .utils import (
detect_fts,
detect_primary_keys,
detect_spatialite,
get_all_foreign_keys,
get_outbound_foreign_keys,
sqlite_timelimit,
sqlite3,
table_columns,
table_column_details,
)
from .inspect import inspect_hash
connections = threading.local()
AttachedDatabase = namedtuple("AttachedDatabase", ("seq", "name", "file"))
class Database:
def __init__(
self, ds, path=None, is_mutable=False, is_memory=False, memory_name=None
):
self.name = None
self.route = None
self.ds = ds
self.path = path
self.is_mutable = is_mutable
self.is_memory = is_memory
self.memory_name = memory_name
if memory_name is not None:
self.is_memory = True
self.is_mutable = True
self.hash = None
self.cached_size = None
self._cached_table_counts = None
self._write_thread = None
self._write_queue = None
if not self.is_mutable and not self.is_memory:
p = Path(path)
self.hash = inspect_hash(p)
self.cached_size = p.stat().st_size
@property
def cached_table_counts(self):
if self._cached_table_counts is not None:
return self._cached_table_counts
# Maybe use self.ds.inspect_data to populate cached_table_counts
if self.ds.inspect_data and self.ds.inspect_data.get(self.name):
self._cached_table_counts = {
key: value["count"]
for key, value in self.ds.inspect_data[self.name]["tables"].items()
}
return self._cached_table_counts
def suggest_name(self):
if self.path:
return Path(self.path).stem
elif self.memory_name:
return self.memory_name
else:
return "db"
def connect(self, write=False):
if self.memory_name:
uri = "file:{}?mode=memory&cache=shared".format(self.memory_name)
conn = sqlite3.connect(
uri,
uri=True,
check_same_thread=False,
)
if not write:
conn.execute("PRAGMA query_only=1")
return conn
if self.is_memory:
return sqlite3.connect(":memory:", uri=True)
# mode=ro or immutable=1?
if self.is_mutable:
qs = "?mode=ro"
else:
qs = "?immutable=1"
assert not (write and not self.is_mutable)
if write:
qs = ""
return sqlite3.connect(
f"file:{self.path}{qs}", uri=True, check_same_thread=False
)
async def execute_write(self, sql, params=None, block=True):
def _inner(conn):
with conn:
return conn.execute(sql, params or [])
with trace("sql", database=self.name, sql=sql.strip(), params=params):
results = await self.execute_write_fn(_inner, block=block)
return results
async def execute_write_script(self, sql, block=True):
def _inner(conn):
with conn:
return conn.executescript(sql)
with trace("sql", database=self.name, sql=sql.strip(), executescript=True):
results = await self.execute_write_fn(_inner, block=block)
return results
async def execute_write_many(self, sql, params_seq, block=True):
def _inner(conn):
count = 0
def count_params(params):
nonlocal count
for param in params:
count += 1
yield param
with conn:
return conn.executemany(sql, count_params(params_seq)), count
with trace(
"sql", database=self.name, sql=sql.strip(), executemany=True
) as kwargs:
results, count = await self.execute_write_fn(_inner, block=block)
kwargs["count"] = count
return results
async def execute_write_fn(self, fn, block=True):
task_id = uuid.uuid5(uuid.NAMESPACE_DNS, "datasette.io")
if self._write_queue is None:
self._write_queue = queue.Queue()
if self._write_thread is None:
self._write_thread = threading.Thread(
target=self._execute_writes, daemon=True
)
self._write_thread.start()
reply_queue = janus.Queue()
self._write_queue.put(WriteTask(fn, task_id, reply_queue))
if block:
result = await reply_queue.async_q.get()
if isinstance(result, Exception):
raise result
else:
return result
else:
return task_id
def _execute_writes(self):
# Infinite looping thread that protects the single write connection
# to this database
conn_exception = None
conn = None
try:
conn = self.connect(write=True)
self.ds._prepare_connection(conn, self.name)
except Exception as e:
conn_exception = e
while True:
task = self._write_queue.get()
if conn_exception is not None:
result = conn_exception
else:
try:
result = task.fn(conn)
except Exception as e:
sys.stderr.write("{}\n".format(e))
sys.stderr.flush()
result = e
task.reply_queue.sync_q.put(result)
async def execute_fn(self, fn):
def in_thread():
conn = getattr(connections, self.name, None)
if not conn:
conn = self.connect()
self.ds._prepare_connection(conn, self.name)
setattr(connections, self.name, conn)
return fn(conn)
return await asyncio.get_event_loop().run_in_executor(
self.ds.executor, in_thread
)
async def execute(
self,
sql,
params=None,
truncate=False,
custom_time_limit=None,
page_size=None,
log_sql_errors=True,
):
"""Executes sql against db_name in a thread"""
page_size = page_size or self.ds.page_size
def sql_operation_in_thread(conn):
time_limit_ms = self.ds.sql_time_limit_ms
if custom_time_limit and custom_time_limit < time_limit_ms:
time_limit_ms = custom_time_limit
with sqlite_timelimit(conn, time_limit_ms):
try:
cursor = conn.cursor()
cursor.execute(sql, params if params is not None else {})
max_returned_rows = self.ds.max_returned_rows
if max_returned_rows == page_size:
max_returned_rows += 1
if max_returned_rows and truncate:
rows = cursor.fetchmany(max_returned_rows + 1)
truncated = len(rows) > max_returned_rows
rows = rows[:max_returned_rows]
else:
rows = cursor.fetchall()
truncated = False
except (sqlite3.OperationalError, sqlite3.DatabaseError) as e:
if e.args == ("interrupted",):
raise QueryInterrupted(e, sql, params)
if log_sql_errors:
sys.stderr.write(
"ERROR: conn={}, sql = {}, params = {}: {}\n".format(
conn, repr(sql), params, e
)
)
sys.stderr.flush()
raise
if truncate:
return Results(rows, truncated, cursor.description)
else:
return Results(rows, False, cursor.description)
with trace("sql", database=self.name, sql=sql.strip(), params=params):
results = await self.execute_fn(sql_operation_in_thread)
return results
@property
def size(self):
if self.is_memory:
return 0
if self.cached_size is not None:
return self.cached_size
else:
return Path(self.path).stat().st_size
async def table_counts(self, limit=10):
if not self.is_mutable and self.cached_table_counts is not None:
return self.cached_table_counts
# Try to get counts for each table, $limit timeout for each count
counts = {}
for table in await self.table_names():
try:
table_count = (
await self.execute(
f"select count(*) from [{table}]",
custom_time_limit=limit,
)
).rows[0][0]
counts[table] = table_count
# In some cases I saw "SQL Logic Error" here in addition to
# QueryInterrupted - so we catch that too:
except (QueryInterrupted, sqlite3.OperationalError, sqlite3.DatabaseError):
counts[table] = None
if not self.is_mutable:
self._cached_table_counts = counts
return counts
@property
def mtime_ns(self):
if self.is_memory:
return None
return Path(self.path).stat().st_mtime_ns
async def attached_databases(self):
# This used to be:
# select seq, name, file from pragma_database_list() where seq > 0
# But SQLite prior to 3.16.0 doesn't support pragma functions
results = await self.execute("PRAGMA database_list;")
# {'seq': 0, 'name': 'main', 'file': ''}
return [AttachedDatabase(*row) for row in results.rows if row["seq"] > 0]
async def table_exists(self, table):
results = await self.execute(
"select 1 from sqlite_master where type='table' and name=?", params=(table,)
)
return bool(results.rows)
async def table_names(self):
results = await self.execute(
"select name from sqlite_master where type='table'"
)
return [r[0] for r in results.rows]
async def table_columns(self, table):
return await self.execute_fn(lambda conn: table_columns(conn, table))
async def table_column_details(self, table):
return await self.execute_fn(lambda conn: table_column_details(conn, table))
async def primary_keys(self, table):
return await self.execute_fn(lambda conn: detect_primary_keys(conn, table))
async def fts_table(self, table):
return await self.execute_fn(lambda conn: detect_fts(conn, table))
async def label_column_for_table(self, table):
explicit_label_column = self.ds.table_metadata(self.name, table).get(
"label_column"
)
if explicit_label_column:
return explicit_label_column
column_names = await self.execute_fn(lambda conn: table_columns(conn, table))
# Is there a name or title column?
name_or_title = [c for c in column_names if c.lower() in ("name", "title")]
if name_or_title:
return name_or_title[0]
# If a table has two columns, one of which is ID, then label_column is the other one
if (
column_names
and len(column_names) == 2
and ("id" in column_names or "pk" in column_names)
):
return [c for c in column_names if c not in ("id", "pk")][0]
# Couldn't find a label:
return None
async def foreign_keys_for_table(self, table):
return await self.execute_fn(
lambda conn: get_outbound_foreign_keys(conn, table)
)
async def hidden_table_names(self):
# Mark tables 'hidden' if they relate to FTS virtual tables
hidden_tables = [
r[0]
for r in (
await self.execute(
"""
select name from sqlite_master
where rootpage = 0
and (
sql like '%VIRTUAL TABLE%USING FTS%'
) or name in ('sqlite_stat1', 'sqlite_stat2', 'sqlite_stat3', 'sqlite_stat4')
"""
)
).rows
]
has_spatialite = await self.execute_fn(detect_spatialite)
if has_spatialite:
# Also hide Spatialite internal tables
hidden_tables += [
"ElementaryGeometries",
"SpatialIndex",
"geometry_columns",
"spatial_ref_sys",
"spatialite_history",
"sql_statements_log",
"sqlite_sequence",
"views_geometry_columns",
"virts_geometry_columns",
"data_licenses",
"KNN",
"KNN2",
] + [
r[0]
for r in (
await self.execute(
"""
select name from sqlite_master
where name like "idx_%"
and type = "table"
"""
)
).rows
]
# Add any from metadata.json
db_metadata = self.ds.metadata(database=self.name)
if "tables" in db_metadata:
hidden_tables += [
t
for t in db_metadata["tables"]
if db_metadata["tables"][t].get("hidden")
]
# Also mark as hidden any tables which start with the name of a hidden table
# e.g. "searchable_fts" implies "searchable_fts_content" should be hidden
for table_name in await self.table_names():
for hidden_table in hidden_tables[:]:
if table_name.startswith(hidden_table):
hidden_tables.append(table_name)
continue
return hidden_tables
async def view_names(self):
results = await self.execute("select name from sqlite_master where type='view'")
return [r[0] for r in results.rows]
async def get_all_foreign_keys(self):
return await self.execute_fn(get_all_foreign_keys)
async def get_table_definition(self, table, type_="table"):
table_definition_rows = list(
await self.execute(
"select sql from sqlite_master where name = :n and type=:t",
{"n": table, "t": type_},
)
)
if not table_definition_rows:
return None
bits = [table_definition_rows[0][0] + ";"]
# Add on any indexes
index_rows = list(
await self.execute(
"select sql from sqlite_master where tbl_name = :n and type='index' and sql is not null",
{"n": table},
)
)
for index_row in index_rows:
bits.append(index_row[0] + ";")
return "\n".join(bits)
async def get_view_definition(self, view):
return await self.get_table_definition(view, "view")
def __repr__(self):
tags = []
if self.is_mutable:
tags.append("mutable")
if self.is_memory:
tags.append("memory")
if self.hash:
tags.append(f"hash={self.hash}")
if self.size is not None:
tags.append(f"size={self.size}")
tags_str = ""
if tags:
tags_str = f" ({', '.join(tags)})"
return f"<Database: {self.name}{tags_str}>"
class WriteTask:
__slots__ = ("fn", "task_id", "reply_queue")
def __init__(self, fn, task_id, reply_queue):
self.fn = fn
self.task_id = task_id
self.reply_queue = reply_queue
class QueryInterrupted(Exception):
pass
class MultipleValues(Exception):
pass
class Results:
def __init__(self, rows, truncated, description):
self.rows = rows
self.truncated = truncated
self.description = description
@property
def columns(self):
return [d[0] for d in self.description]
def first(self):
if self.rows:
return self.rows[0]
else:
return None
def single_value(self):
if self.rows and 1 == len(self.rows) and 1 == len(self.rows[0]):
return self.rows[0][0]
else:
raise MultipleValues
def __iter__(self):
return iter(self.rows)
def __len__(self):
return len(self.rows)