[Telemetry] Move some tests from page_runner_unittest to user_story_runner_unittest.
[chromium-blink-merge.git] / sql / connection.cc
blobcc7e69dba741f0fdae3e23713c0a2104a6d6ad21
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "sql/connection.h"
7 #include <string.h>
9 #include "base/files/file_path.h"
10 #include "base/files/file_util.h"
11 #include "base/lazy_instance.h"
12 #include "base/logging.h"
13 #include "base/metrics/histogram.h"
14 #include "base/metrics/sparse_histogram.h"
15 #include "base/strings/string_split.h"
16 #include "base/strings/string_util.h"
17 #include "base/strings/stringprintf.h"
18 #include "base/strings/utf_string_conversions.h"
19 #include "base/synchronization/lock.h"
20 #include "sql/statement.h"
21 #include "third_party/sqlite/sqlite3.h"
23 #if defined(OS_IOS) && defined(USE_SYSTEM_SQLITE)
24 #include "third_party/sqlite/src/ext/icu/sqliteicu.h"
25 #endif
27 namespace {
29 // Spin for up to a second waiting for the lock to clear when setting
30 // up the database.
31 // TODO(shess): Better story on this. http://crbug.com/56559
32 const int kBusyTimeoutSeconds = 1;
34 class ScopedBusyTimeout {
35 public:
36 explicit ScopedBusyTimeout(sqlite3* db)
37 : db_(db) {
39 ~ScopedBusyTimeout() {
40 sqlite3_busy_timeout(db_, 0);
43 int SetTimeout(base::TimeDelta timeout) {
44 DCHECK_LT(timeout.InMilliseconds(), INT_MAX);
45 return sqlite3_busy_timeout(db_,
46 static_cast<int>(timeout.InMilliseconds()));
49 private:
50 sqlite3* db_;
53 // Helper to "safely" enable writable_schema. No error checking
54 // because it is reasonable to just forge ahead in case of an error.
55 // If turning it on fails, then most likely nothing will work, whereas
56 // if turning it off fails, it only matters if some code attempts to
57 // continue working with the database and tries to modify the
58 // sqlite_master table (none of our code does this).
59 class ScopedWritableSchema {
60 public:
61 explicit ScopedWritableSchema(sqlite3* db)
62 : db_(db) {
63 sqlite3_exec(db_, "PRAGMA writable_schema=1", NULL, NULL, NULL);
65 ~ScopedWritableSchema() {
66 sqlite3_exec(db_, "PRAGMA writable_schema=0", NULL, NULL, NULL);
69 private:
70 sqlite3* db_;
73 // Helper to wrap the sqlite3_backup_*() step of Raze(). Return
74 // SQLite error code from running the backup step.
75 int BackupDatabase(sqlite3* src, sqlite3* dst, const char* db_name) {
76 DCHECK_NE(src, dst);
77 sqlite3_backup* backup = sqlite3_backup_init(dst, db_name, src, db_name);
78 if (!backup) {
79 // Since this call only sets things up, this indicates a gross
80 // error in SQLite.
81 DLOG(FATAL) << "Unable to start sqlite3_backup(): " << sqlite3_errmsg(dst);
82 return sqlite3_errcode(dst);
85 // -1 backs up the entire database.
86 int rc = sqlite3_backup_step(backup, -1);
87 int pages = sqlite3_backup_pagecount(backup);
88 sqlite3_backup_finish(backup);
90 // If successful, exactly one page should have been backed up. If
91 // this breaks, check this function to make sure assumptions aren't
92 // being broken.
93 if (rc == SQLITE_DONE)
94 DCHECK_EQ(pages, 1);
96 return rc;
99 // Be very strict on attachment point. SQLite can handle a much wider
100 // character set with appropriate quoting, but Chromium code should
101 // just use clean names to start with.
102 bool ValidAttachmentPoint(const char* attachment_point) {
103 for (size_t i = 0; attachment_point[i]; ++i) {
104 if (!((attachment_point[i] >= '0' && attachment_point[i] <= '9') ||
105 (attachment_point[i] >= 'a' && attachment_point[i] <= 'z') ||
106 (attachment_point[i] >= 'A' && attachment_point[i] <= 'Z') ||
107 attachment_point[i] == '_')) {
108 return false;
111 return true;
114 // SQLite automatically calls sqlite3_initialize() lazily, but
115 // sqlite3_initialize() uses double-checked locking and thus can have
116 // data races.
118 // TODO(shess): Another alternative would be to have
119 // sqlite3_initialize() called as part of process bring-up. If this
120 // is changed, remove the dynamic_annotations dependency in sql.gyp.
121 base::LazyInstance<base::Lock>::Leaky
122 g_sqlite_init_lock = LAZY_INSTANCE_INITIALIZER;
123 void InitializeSqlite() {
124 base::AutoLock lock(g_sqlite_init_lock.Get());
125 sqlite3_initialize();
128 // Helper to get the sqlite3_file* associated with the "main" database.
129 int GetSqlite3File(sqlite3* db, sqlite3_file** file) {
130 *file = NULL;
131 int rc = sqlite3_file_control(db, NULL, SQLITE_FCNTL_FILE_POINTER, file);
132 if (rc != SQLITE_OK)
133 return rc;
135 // TODO(shess): NULL in file->pMethods has been observed on android_dbg
136 // content_unittests, even though it should not be possible.
137 // http://crbug.com/329982
138 if (!*file || !(*file)->pMethods)
139 return SQLITE_ERROR;
141 return rc;
144 } // namespace
146 namespace sql {
148 // static
149 Connection::ErrorIgnorerCallback* Connection::current_ignorer_cb_ = NULL;
151 // static
152 bool Connection::ShouldIgnoreSqliteError(int error) {
153 if (!current_ignorer_cb_)
154 return false;
155 return current_ignorer_cb_->Run(error);
158 // static
159 void Connection::SetErrorIgnorer(Connection::ErrorIgnorerCallback* cb) {
160 CHECK(current_ignorer_cb_ == NULL);
161 current_ignorer_cb_ = cb;
164 // static
165 void Connection::ResetErrorIgnorer() {
166 CHECK(current_ignorer_cb_);
167 current_ignorer_cb_ = NULL;
170 bool StatementID::operator<(const StatementID& other) const {
171 if (number_ != other.number_)
172 return number_ < other.number_;
173 return strcmp(str_, other.str_) < 0;
176 Connection::StatementRef::StatementRef(Connection* connection,
177 sqlite3_stmt* stmt,
178 bool was_valid)
179 : connection_(connection),
180 stmt_(stmt),
181 was_valid_(was_valid) {
182 if (connection)
183 connection_->StatementRefCreated(this);
186 Connection::StatementRef::~StatementRef() {
187 if (connection_)
188 connection_->StatementRefDeleted(this);
189 Close(false);
192 void Connection::StatementRef::Close(bool forced) {
193 if (stmt_) {
194 // Call to AssertIOAllowed() cannot go at the beginning of the function
195 // because Close() is called unconditionally from destructor to clean
196 // connection_. And if this is inactive statement this won't cause any
197 // disk access and destructor most probably will be called on thread
198 // not allowing disk access.
199 // TODO(paivanof@gmail.com): This should move to the beginning
200 // of the function. http://crbug.com/136655.
201 AssertIOAllowed();
202 sqlite3_finalize(stmt_);
203 stmt_ = NULL;
205 connection_ = NULL; // The connection may be getting deleted.
207 // Forced close is expected to happen from a statement error
208 // handler. In that case maintain the sense of |was_valid_| which
209 // previously held for this ref.
210 was_valid_ = was_valid_ && forced;
213 Connection::Connection()
214 : db_(NULL),
215 page_size_(0),
216 cache_size_(0),
217 exclusive_locking_(false),
218 restrict_to_user_(false),
219 transaction_nesting_(0),
220 needs_rollback_(false),
221 in_memory_(false),
222 poisoned_(false) {
225 Connection::~Connection() {
226 Close();
229 bool Connection::Open(const base::FilePath& path) {
230 if (!histogram_tag_.empty()) {
231 int64 size_64 = 0;
232 if (base::GetFileSize(path, &size_64)) {
233 size_t sample = static_cast<size_t>(size_64 / 1024);
234 std::string full_histogram_name = "Sqlite.SizeKB." + histogram_tag_;
235 base::HistogramBase* histogram =
236 base::Histogram::FactoryGet(
237 full_histogram_name, 1, 1000000, 50,
238 base::HistogramBase::kUmaTargetedHistogramFlag);
239 if (histogram)
240 histogram->Add(sample);
244 #if defined(OS_WIN)
245 return OpenInternal(base::WideToUTF8(path.value()), RETRY_ON_POISON);
246 #elif defined(OS_POSIX)
247 return OpenInternal(path.value(), RETRY_ON_POISON);
248 #endif
251 bool Connection::OpenInMemory() {
252 in_memory_ = true;
253 return OpenInternal(":memory:", NO_RETRY);
256 bool Connection::OpenTemporary() {
257 return OpenInternal("", NO_RETRY);
260 void Connection::CloseInternal(bool forced) {
261 // TODO(shess): Calling "PRAGMA journal_mode = DELETE" at this point
262 // will delete the -journal file. For ChromiumOS or other more
263 // embedded systems, this is probably not appropriate, whereas on
264 // desktop it might make some sense.
266 // sqlite3_close() needs all prepared statements to be finalized.
268 // Release cached statements.
269 statement_cache_.clear();
271 // With cached statements released, in-use statements will remain.
272 // Closing the database while statements are in use is an API
273 // violation, except for forced close (which happens from within a
274 // statement's error handler).
275 DCHECK(forced || open_statements_.empty());
277 // Deactivate any outstanding statements so sqlite3_close() works.
278 for (StatementRefSet::iterator i = open_statements_.begin();
279 i != open_statements_.end(); ++i)
280 (*i)->Close(forced);
281 open_statements_.clear();
283 if (db_) {
284 // Call to AssertIOAllowed() cannot go at the beginning of the function
285 // because Close() must be called from destructor to clean
286 // statement_cache_, it won't cause any disk access and it most probably
287 // will happen on thread not allowing disk access.
288 // TODO(paivanof@gmail.com): This should move to the beginning
289 // of the function. http://crbug.com/136655.
290 AssertIOAllowed();
292 int rc = sqlite3_close(db_);
293 if (rc != SQLITE_OK) {
294 UMA_HISTOGRAM_SPARSE_SLOWLY("Sqlite.CloseFailure", rc);
295 DLOG(FATAL) << "sqlite3_close failed: " << GetErrorMessage();
298 db_ = NULL;
301 void Connection::Close() {
302 // If the database was already closed by RazeAndClose(), then no
303 // need to close again. Clear the |poisoned_| bit so that incorrect
304 // API calls are caught.
305 if (poisoned_) {
306 poisoned_ = false;
307 return;
310 CloseInternal(false);
313 void Connection::Preload() {
314 AssertIOAllowed();
316 if (!db_) {
317 DLOG_IF(FATAL, !poisoned_) << "Cannot preload null db";
318 return;
321 // Use local settings if provided, otherwise use documented defaults. The
322 // actual results could be fetching via PRAGMA calls.
323 const int page_size = page_size_ ? page_size_ : 1024;
324 sqlite3_int64 preload_size = page_size * (cache_size_ ? cache_size_ : 2000);
325 if (preload_size < 1)
326 return;
328 sqlite3_file* file = NULL;
329 int rc = GetSqlite3File(db_, &file);
330 if (rc != SQLITE_OK)
331 return;
333 sqlite3_int64 file_size = 0;
334 rc = file->pMethods->xFileSize(file, &file_size);
335 if (rc != SQLITE_OK)
336 return;
338 // Don't preload more than the file contains.
339 if (preload_size > file_size)
340 preload_size = file_size;
342 scoped_ptr<char[]> buf(new char[page_size]);
343 for (sqlite3_int64 pos = 0; pos < file_size; pos += page_size) {
344 rc = file->pMethods->xRead(file, buf.get(), page_size, pos);
345 if (rc != SQLITE_OK)
346 return;
350 void Connection::TrimMemory(bool aggressively) {
351 if (!db_)
352 return;
354 // TODO(shess): investigate using sqlite3_db_release_memory() when possible.
355 int original_cache_size;
357 Statement sql_get_original(GetUniqueStatement("PRAGMA cache_size"));
358 if (!sql_get_original.Step()) {
359 DLOG(WARNING) << "Could not get cache size " << GetErrorMessage();
360 return;
362 original_cache_size = sql_get_original.ColumnInt(0);
364 int shrink_cache_size = aggressively ? 1 : (original_cache_size / 2);
366 // Force sqlite to try to reduce page cache usage.
367 const std::string sql_shrink =
368 base::StringPrintf("PRAGMA cache_size=%d", shrink_cache_size);
369 if (!Execute(sql_shrink.c_str()))
370 DLOG(WARNING) << "Could not shrink cache size: " << GetErrorMessage();
372 // Restore cache size.
373 const std::string sql_restore =
374 base::StringPrintf("PRAGMA cache_size=%d", original_cache_size);
375 if (!Execute(sql_restore.c_str()))
376 DLOG(WARNING) << "Could not restore cache size: " << GetErrorMessage();
379 // Create an in-memory database with the existing database's page
380 // size, then backup that database over the existing database.
381 bool Connection::Raze() {
382 AssertIOAllowed();
384 if (!db_) {
385 DLOG_IF(FATAL, !poisoned_) << "Cannot raze null db";
386 return false;
389 if (transaction_nesting_ > 0) {
390 DLOG(FATAL) << "Cannot raze within a transaction";
391 return false;
394 sql::Connection null_db;
395 if (!null_db.OpenInMemory()) {
396 DLOG(FATAL) << "Unable to open in-memory database.";
397 return false;
400 if (page_size_) {
401 // Enforce SQLite restrictions on |page_size_|.
402 DCHECK(!(page_size_ & (page_size_ - 1)))
403 << " page_size_ " << page_size_ << " is not a power of two.";
404 const int kSqliteMaxPageSize = 32768; // from sqliteLimit.h
405 DCHECK_LE(page_size_, kSqliteMaxPageSize);
406 const std::string sql =
407 base::StringPrintf("PRAGMA page_size=%d", page_size_);
408 if (!null_db.Execute(sql.c_str()))
409 return false;
412 #if defined(OS_ANDROID)
413 // Android compiles with SQLITE_DEFAULT_AUTOVACUUM. Unfortunately,
414 // in-memory databases do not respect this define.
415 // TODO(shess): Figure out a way to set this without using platform
416 // specific code. AFAICT from sqlite3.c, the only way to do it
417 // would be to create an actual filesystem database, which is
418 // unfortunate.
419 if (!null_db.Execute("PRAGMA auto_vacuum = 1"))
420 return false;
421 #endif
423 // The page size doesn't take effect until a database has pages, and
424 // at this point the null database has none. Changing the schema
425 // version will create the first page. This will not affect the
426 // schema version in the resulting database, as SQLite's backup
427 // implementation propagates the schema version from the original
428 // connection to the new version of the database, incremented by one
429 // so that other readers see the schema change and act accordingly.
430 if (!null_db.Execute("PRAGMA schema_version = 1"))
431 return false;
433 // SQLite tracks the expected number of database pages in the first
434 // page, and if it does not match the total retrieved from a
435 // filesystem call, treats the database as corrupt. This situation
436 // breaks almost all SQLite calls. "PRAGMA writable_schema" can be
437 // used to hint to SQLite to soldier on in that case, specifically
438 // for purposes of recovery. [See SQLITE_CORRUPT_BKPT case in
439 // sqlite3.c lockBtree().]
440 // TODO(shess): With this, "PRAGMA auto_vacuum" and "PRAGMA
441 // page_size" can be used to query such a database.
442 ScopedWritableSchema writable_schema(db_);
444 const char* kMain = "main";
445 int rc = BackupDatabase(null_db.db_, db_, kMain);
446 UMA_HISTOGRAM_SPARSE_SLOWLY("Sqlite.RazeDatabase",rc);
448 // The destination database was locked.
449 if (rc == SQLITE_BUSY) {
450 return false;
453 // SQLITE_NOTADB can happen if page 1 of db_ exists, but is not
454 // formatted correctly. SQLITE_IOERR_SHORT_READ can happen if db_
455 // isn't even big enough for one page. Either way, reach in and
456 // truncate it before trying again.
457 // TODO(shess): Maybe it would be worthwhile to just truncate from
458 // the get-go?
459 if (rc == SQLITE_NOTADB || rc == SQLITE_IOERR_SHORT_READ) {
460 sqlite3_file* file = NULL;
461 rc = GetSqlite3File(db_, &file);
462 if (rc != SQLITE_OK) {
463 DLOG(FATAL) << "Failure getting file handle.";
464 return false;
467 rc = file->pMethods->xTruncate(file, 0);
468 if (rc != SQLITE_OK) {
469 UMA_HISTOGRAM_SPARSE_SLOWLY("Sqlite.RazeDatabaseTruncate",rc);
470 DLOG(FATAL) << "Failed to truncate file.";
471 return false;
474 rc = BackupDatabase(null_db.db_, db_, kMain);
475 UMA_HISTOGRAM_SPARSE_SLOWLY("Sqlite.RazeDatabase2",rc);
477 if (rc != SQLITE_DONE) {
478 DLOG(FATAL) << "Failed retrying Raze().";
482 // The entire database should have been backed up.
483 if (rc != SQLITE_DONE) {
484 // TODO(shess): Figure out which other cases can happen.
485 DLOG(FATAL) << "Unable to copy entire null database.";
486 return false;
489 return true;
492 bool Connection::RazeWithTimout(base::TimeDelta timeout) {
493 if (!db_) {
494 DLOG_IF(FATAL, !poisoned_) << "Cannot raze null db";
495 return false;
498 ScopedBusyTimeout busy_timeout(db_);
499 busy_timeout.SetTimeout(timeout);
500 return Raze();
503 bool Connection::RazeAndClose() {
504 if (!db_) {
505 DLOG_IF(FATAL, !poisoned_) << "Cannot raze null db";
506 return false;
509 // Raze() cannot run in a transaction.
510 RollbackAllTransactions();
512 bool result = Raze();
514 CloseInternal(true);
516 // Mark the database so that future API calls fail appropriately,
517 // but don't DCHECK (because after calling this function they are
518 // expected to fail).
519 poisoned_ = true;
521 return result;
524 void Connection::Poison() {
525 if (!db_) {
526 DLOG_IF(FATAL, !poisoned_) << "Cannot poison null db";
527 return;
530 RollbackAllTransactions();
531 CloseInternal(true);
533 // Mark the database so that future API calls fail appropriately,
534 // but don't DCHECK (because after calling this function they are
535 // expected to fail).
536 poisoned_ = true;
539 // TODO(shess): To the extent possible, figure out the optimal
540 // ordering for these deletes which will prevent other connections
541 // from seeing odd behavior. For instance, it may be necessary to
542 // manually lock the main database file in a SQLite-compatible fashion
543 // (to prevent other processes from opening it), then delete the
544 // journal files, then delete the main database file. Another option
545 // might be to lock the main database file and poison the header with
546 // junk to prevent other processes from opening it successfully (like
547 // Gears "SQLite poison 3" trick).
549 // static
550 bool Connection::Delete(const base::FilePath& path) {
551 base::ThreadRestrictions::AssertIOAllowed();
553 base::FilePath journal_path(path.value() + FILE_PATH_LITERAL("-journal"));
554 base::FilePath wal_path(path.value() + FILE_PATH_LITERAL("-wal"));
556 base::DeleteFile(journal_path, false);
557 base::DeleteFile(wal_path, false);
558 base::DeleteFile(path, false);
560 return !base::PathExists(journal_path) &&
561 !base::PathExists(wal_path) &&
562 !base::PathExists(path);
565 bool Connection::BeginTransaction() {
566 if (needs_rollback_) {
567 DCHECK_GT(transaction_nesting_, 0);
569 // When we're going to rollback, fail on this begin and don't actually
570 // mark us as entering the nested transaction.
571 return false;
574 bool success = true;
575 if (!transaction_nesting_) {
576 needs_rollback_ = false;
578 Statement begin(GetCachedStatement(SQL_FROM_HERE, "BEGIN TRANSACTION"));
579 if (!begin.Run())
580 return false;
582 transaction_nesting_++;
583 return success;
586 void Connection::RollbackTransaction() {
587 if (!transaction_nesting_) {
588 DLOG_IF(FATAL, !poisoned_) << "Rolling back a nonexistent transaction";
589 return;
592 transaction_nesting_--;
594 if (transaction_nesting_ > 0) {
595 // Mark the outermost transaction as needing rollback.
596 needs_rollback_ = true;
597 return;
600 DoRollback();
603 bool Connection::CommitTransaction() {
604 if (!transaction_nesting_) {
605 DLOG_IF(FATAL, !poisoned_) << "Rolling back a nonexistent transaction";
606 return false;
608 transaction_nesting_--;
610 if (transaction_nesting_ > 0) {
611 // Mark any nested transactions as failing after we've already got one.
612 return !needs_rollback_;
615 if (needs_rollback_) {
616 DoRollback();
617 return false;
620 Statement commit(GetCachedStatement(SQL_FROM_HERE, "COMMIT"));
621 return commit.Run();
624 void Connection::RollbackAllTransactions() {
625 if (transaction_nesting_ > 0) {
626 transaction_nesting_ = 0;
627 DoRollback();
631 bool Connection::AttachDatabase(const base::FilePath& other_db_path,
632 const char* attachment_point) {
633 DCHECK(ValidAttachmentPoint(attachment_point));
635 Statement s(GetUniqueStatement("ATTACH DATABASE ? AS ?"));
636 #if OS_WIN
637 s.BindString16(0, other_db_path.value());
638 #else
639 s.BindString(0, other_db_path.value());
640 #endif
641 s.BindString(1, attachment_point);
642 return s.Run();
645 bool Connection::DetachDatabase(const char* attachment_point) {
646 DCHECK(ValidAttachmentPoint(attachment_point));
648 Statement s(GetUniqueStatement("DETACH DATABASE ?"));
649 s.BindString(0, attachment_point);
650 return s.Run();
653 int Connection::ExecuteAndReturnErrorCode(const char* sql) {
654 AssertIOAllowed();
655 if (!db_) {
656 DLOG_IF(FATAL, !poisoned_) << "Illegal use of connection without a db";
657 return SQLITE_ERROR;
659 return sqlite3_exec(db_, sql, NULL, NULL, NULL);
662 bool Connection::Execute(const char* sql) {
663 if (!db_) {
664 DLOG_IF(FATAL, !poisoned_) << "Illegal use of connection without a db";
665 return false;
668 int error = ExecuteAndReturnErrorCode(sql);
669 if (error != SQLITE_OK)
670 error = OnSqliteError(error, NULL, sql);
672 // This needs to be a FATAL log because the error case of arriving here is
673 // that there's a malformed SQL statement. This can arise in development if
674 // a change alters the schema but not all queries adjust. This can happen
675 // in production if the schema is corrupted.
676 if (error == SQLITE_ERROR)
677 DLOG(FATAL) << "SQL Error in " << sql << ", " << GetErrorMessage();
678 return error == SQLITE_OK;
681 bool Connection::ExecuteWithTimeout(const char* sql, base::TimeDelta timeout) {
682 if (!db_) {
683 DLOG_IF(FATAL, !poisoned_) << "Illegal use of connection without a db";
684 return false;
687 ScopedBusyTimeout busy_timeout(db_);
688 busy_timeout.SetTimeout(timeout);
689 return Execute(sql);
692 bool Connection::HasCachedStatement(const StatementID& id) const {
693 return statement_cache_.find(id) != statement_cache_.end();
696 scoped_refptr<Connection::StatementRef> Connection::GetCachedStatement(
697 const StatementID& id,
698 const char* sql) {
699 CachedStatementMap::iterator i = statement_cache_.find(id);
700 if (i != statement_cache_.end()) {
701 // Statement is in the cache. It should still be active (we're the only
702 // one invalidating cached statements, and we'll remove it from the cache
703 // if we do that. Make sure we reset it before giving out the cached one in
704 // case it still has some stuff bound.
705 DCHECK(i->second->is_valid());
706 sqlite3_reset(i->second->stmt());
707 return i->second;
710 scoped_refptr<StatementRef> statement = GetUniqueStatement(sql);
711 if (statement->is_valid())
712 statement_cache_[id] = statement; // Only cache valid statements.
713 return statement;
716 scoped_refptr<Connection::StatementRef> Connection::GetUniqueStatement(
717 const char* sql) {
718 AssertIOAllowed();
720 // Return inactive statement.
721 if (!db_)
722 return new StatementRef(NULL, NULL, poisoned_);
724 sqlite3_stmt* stmt = NULL;
725 int rc = sqlite3_prepare_v2(db_, sql, -1, &stmt, NULL);
726 if (rc != SQLITE_OK) {
727 // This is evidence of a syntax error in the incoming SQL.
728 DLOG(FATAL) << "SQL compile error " << GetErrorMessage();
730 // It could also be database corruption.
731 OnSqliteError(rc, NULL, sql);
732 return new StatementRef(NULL, NULL, false);
734 return new StatementRef(this, stmt, true);
737 scoped_refptr<Connection::StatementRef> Connection::GetUntrackedStatement(
738 const char* sql) const {
739 // Return inactive statement.
740 if (!db_)
741 return new StatementRef(NULL, NULL, poisoned_);
743 sqlite3_stmt* stmt = NULL;
744 int rc = sqlite3_prepare_v2(db_, sql, -1, &stmt, NULL);
745 if (rc != SQLITE_OK) {
746 // This is evidence of a syntax error in the incoming SQL.
747 DLOG(FATAL) << "SQL compile error " << GetErrorMessage();
748 return new StatementRef(NULL, NULL, false);
750 return new StatementRef(NULL, stmt, true);
753 std::string Connection::GetSchema() const {
754 // The ORDER BY should not be necessary, but relying on organic
755 // order for something like this is questionable.
756 const char* kSql =
757 "SELECT type, name, tbl_name, sql "
758 "FROM sqlite_master ORDER BY 1, 2, 3, 4";
759 Statement statement(GetUntrackedStatement(kSql));
761 std::string schema;
762 while (statement.Step()) {
763 schema += statement.ColumnString(0);
764 schema += '|';
765 schema += statement.ColumnString(1);
766 schema += '|';
767 schema += statement.ColumnString(2);
768 schema += '|';
769 schema += statement.ColumnString(3);
770 schema += '\n';
773 return schema;
776 bool Connection::IsSQLValid(const char* sql) {
777 AssertIOAllowed();
778 if (!db_) {
779 DLOG_IF(FATAL, !poisoned_) << "Illegal use of connection without a db";
780 return false;
783 sqlite3_stmt* stmt = NULL;
784 if (sqlite3_prepare_v2(db_, sql, -1, &stmt, NULL) != SQLITE_OK)
785 return false;
787 sqlite3_finalize(stmt);
788 return true;
791 bool Connection::DoesTableExist(const char* table_name) const {
792 return DoesTableOrIndexExist(table_name, "table");
795 bool Connection::DoesIndexExist(const char* index_name) const {
796 return DoesTableOrIndexExist(index_name, "index");
799 bool Connection::DoesTableOrIndexExist(
800 const char* name, const char* type) const {
801 const char* kSql = "SELECT name FROM sqlite_master WHERE type=? AND name=?";
802 Statement statement(GetUntrackedStatement(kSql));
803 statement.BindString(0, type);
804 statement.BindString(1, name);
806 return statement.Step(); // Table exists if any row was returned.
809 bool Connection::DoesColumnExist(const char* table_name,
810 const char* column_name) const {
811 std::string sql("PRAGMA TABLE_INFO(");
812 sql.append(table_name);
813 sql.append(")");
815 Statement statement(GetUntrackedStatement(sql.c_str()));
816 while (statement.Step()) {
817 if (!statement.ColumnString(1).compare(column_name))
818 return true;
820 return false;
823 int64 Connection::GetLastInsertRowId() const {
824 if (!db_) {
825 DLOG_IF(FATAL, !poisoned_) << "Illegal use of connection without a db";
826 return 0;
828 return sqlite3_last_insert_rowid(db_);
831 int Connection::GetLastChangeCount() const {
832 if (!db_) {
833 DLOG_IF(FATAL, !poisoned_) << "Illegal use of connection without a db";
834 return 0;
836 return sqlite3_changes(db_);
839 int Connection::GetErrorCode() const {
840 if (!db_)
841 return SQLITE_ERROR;
842 return sqlite3_errcode(db_);
845 int Connection::GetLastErrno() const {
846 if (!db_)
847 return -1;
849 int err = 0;
850 if (SQLITE_OK != sqlite3_file_control(db_, NULL, SQLITE_LAST_ERRNO, &err))
851 return -2;
853 return err;
856 const char* Connection::GetErrorMessage() const {
857 if (!db_)
858 return "sql::Connection has no connection.";
859 return sqlite3_errmsg(db_);
862 bool Connection::OpenInternal(const std::string& file_name,
863 Connection::Retry retry_flag) {
864 AssertIOAllowed();
866 if (db_) {
867 DLOG(FATAL) << "sql::Connection is already open.";
868 return false;
871 // Make sure sqlite3_initialize() is called before anything else.
872 InitializeSqlite();
874 // If |poisoned_| is set, it means an error handler called
875 // RazeAndClose(). Until regular Close() is called, the caller
876 // should be treating the database as open, but is_open() currently
877 // only considers the sqlite3 handle's state.
878 // TODO(shess): Revise is_open() to consider poisoned_, and review
879 // to see if any non-testing code even depends on it.
880 DLOG_IF(FATAL, poisoned_) << "sql::Connection is already open.";
881 poisoned_ = false;
883 int err = sqlite3_open(file_name.c_str(), &db_);
884 if (err != SQLITE_OK) {
885 // Extended error codes cannot be enabled until a handle is
886 // available, fetch manually.
887 err = sqlite3_extended_errcode(db_);
889 // Histogram failures specific to initial open for debugging
890 // purposes.
891 UMA_HISTOGRAM_SPARSE_SLOWLY("Sqlite.OpenFailure", err);
893 OnSqliteError(err, NULL, "-- sqlite3_open()");
894 bool was_poisoned = poisoned_;
895 Close();
897 if (was_poisoned && retry_flag == RETRY_ON_POISON)
898 return OpenInternal(file_name, NO_RETRY);
899 return false;
902 // TODO(shess): OS_WIN support?
903 #if defined(OS_POSIX)
904 if (restrict_to_user_) {
905 DCHECK_NE(file_name, std::string(":memory"));
906 base::FilePath file_path(file_name);
907 int mode = 0;
908 // TODO(shess): Arguably, failure to retrieve and change
909 // permissions should be fatal if the file exists.
910 if (base::GetPosixFilePermissions(file_path, &mode)) {
911 mode &= base::FILE_PERMISSION_USER_MASK;
912 base::SetPosixFilePermissions(file_path, mode);
914 // SQLite sets the permissions on these files from the main
915 // database on create. Set them here in case they already exist
916 // at this point. Failure to set these permissions should not
917 // be fatal unless the file doesn't exist.
918 base::FilePath journal_path(file_name + FILE_PATH_LITERAL("-journal"));
919 base::FilePath wal_path(file_name + FILE_PATH_LITERAL("-wal"));
920 base::SetPosixFilePermissions(journal_path, mode);
921 base::SetPosixFilePermissions(wal_path, mode);
924 #endif // defined(OS_POSIX)
926 // SQLite uses a lookaside buffer to improve performance of small mallocs.
927 // Chromium already depends on small mallocs being efficient, so we disable
928 // this to avoid the extra memory overhead.
929 // This must be called immediatly after opening the database before any SQL
930 // statements are run.
931 sqlite3_db_config(db_, SQLITE_DBCONFIG_LOOKASIDE, NULL, 0, 0);
933 // Enable extended result codes to provide more color on I/O errors.
934 // Not having extended result codes is not a fatal problem, as
935 // Chromium code does not attempt to handle I/O errors anyhow. The
936 // current implementation always returns SQLITE_OK, the DCHECK is to
937 // quickly notify someone if SQLite changes.
938 err = sqlite3_extended_result_codes(db_, 1);
939 DCHECK_EQ(err, SQLITE_OK) << "Could not enable extended result codes";
941 // sqlite3_open() does not actually read the database file (unless a
942 // hot journal is found). Successfully executing this pragma on an
943 // existing database requires a valid header on page 1.
944 // TODO(shess): For now, just probing to see what the lay of the
945 // land is. If it's mostly SQLITE_NOTADB, then the database should
946 // be razed.
947 err = ExecuteAndReturnErrorCode("PRAGMA auto_vacuum");
948 if (err != SQLITE_OK)
949 UMA_HISTOGRAM_SPARSE_SLOWLY("Sqlite.OpenProbeFailure", err);
951 #if defined(OS_IOS) && defined(USE_SYSTEM_SQLITE)
952 // The version of SQLite shipped with iOS doesn't enable ICU, which includes
953 // REGEXP support. Add it in dynamically.
954 err = sqlite3IcuInit(db_);
955 DCHECK_EQ(err, SQLITE_OK) << "Could not enable ICU support";
956 #endif // OS_IOS && USE_SYSTEM_SQLITE
958 // If indicated, lock up the database before doing anything else, so
959 // that the following code doesn't have to deal with locking.
960 // TODO(shess): This code is brittle. Find the cases where code
961 // doesn't request |exclusive_locking_| and audit that it does the
962 // right thing with SQLITE_BUSY, and that it doesn't make
963 // assumptions about who might change things in the database.
964 // http://crbug.com/56559
965 if (exclusive_locking_) {
966 // TODO(shess): This should probably be a failure. Code which
967 // requests exclusive locking but doesn't get it is almost certain
968 // to be ill-tested.
969 ignore_result(Execute("PRAGMA locking_mode=EXCLUSIVE"));
972 // http://www.sqlite.org/pragma.html#pragma_journal_mode
973 // DELETE (default) - delete -journal file to commit.
974 // TRUNCATE - truncate -journal file to commit.
975 // PERSIST - zero out header of -journal file to commit.
976 // journal_size_limit provides size to trim to in PERSIST.
977 // TODO(shess): Figure out if PERSIST and journal_size_limit really
978 // matter. In theory, it keeps pages pre-allocated, so if
979 // transactions usually fit, it should be faster.
980 ignore_result(Execute("PRAGMA journal_mode = PERSIST"));
981 ignore_result(Execute("PRAGMA journal_size_limit = 16384"));
983 const base::TimeDelta kBusyTimeout =
984 base::TimeDelta::FromSeconds(kBusyTimeoutSeconds);
986 if (page_size_ != 0) {
987 // Enforce SQLite restrictions on |page_size_|.
988 DCHECK(!(page_size_ & (page_size_ - 1)))
989 << " page_size_ " << page_size_ << " is not a power of two.";
990 const int kSqliteMaxPageSize = 32768; // from sqliteLimit.h
991 DCHECK_LE(page_size_, kSqliteMaxPageSize);
992 const std::string sql =
993 base::StringPrintf("PRAGMA page_size=%d", page_size_);
994 ignore_result(ExecuteWithTimeout(sql.c_str(), kBusyTimeout));
997 if (cache_size_ != 0) {
998 const std::string sql =
999 base::StringPrintf("PRAGMA cache_size=%d", cache_size_);
1000 ignore_result(ExecuteWithTimeout(sql.c_str(), kBusyTimeout));
1003 if (!ExecuteWithTimeout("PRAGMA secure_delete=ON", kBusyTimeout)) {
1004 bool was_poisoned = poisoned_;
1005 Close();
1006 if (was_poisoned && retry_flag == RETRY_ON_POISON)
1007 return OpenInternal(file_name, NO_RETRY);
1008 return false;
1011 return true;
1014 void Connection::DoRollback() {
1015 Statement rollback(GetCachedStatement(SQL_FROM_HERE, "ROLLBACK"));
1016 rollback.Run();
1017 needs_rollback_ = false;
1020 void Connection::StatementRefCreated(StatementRef* ref) {
1021 DCHECK(open_statements_.find(ref) == open_statements_.end());
1022 open_statements_.insert(ref);
1025 void Connection::StatementRefDeleted(StatementRef* ref) {
1026 StatementRefSet::iterator i = open_statements_.find(ref);
1027 if (i == open_statements_.end())
1028 DLOG(FATAL) << "Could not find statement";
1029 else
1030 open_statements_.erase(i);
1033 void Connection::AddTaggedHistogram(const std::string& name,
1034 size_t sample) const {
1035 if (histogram_tag_.empty())
1036 return;
1038 // TODO(shess): The histogram macros create a bit of static storage
1039 // for caching the histogram object. This code shouldn't execute
1040 // often enough for such caching to be crucial. If it becomes an
1041 // issue, the object could be cached alongside histogram_prefix_.
1042 std::string full_histogram_name = name + "." + histogram_tag_;
1043 base::HistogramBase* histogram =
1044 base::SparseHistogram::FactoryGet(
1045 full_histogram_name,
1046 base::HistogramBase::kUmaTargetedHistogramFlag);
1047 if (histogram)
1048 histogram->Add(sample);
1051 int Connection::OnSqliteError(int err, sql::Statement *stmt, const char* sql) {
1052 UMA_HISTOGRAM_SPARSE_SLOWLY("Sqlite.Error", err);
1053 AddTaggedHistogram("Sqlite.Error", err);
1055 // Always log the error.
1056 if (!sql && stmt)
1057 sql = stmt->GetSQLStatement();
1058 if (!sql)
1059 sql = "-- unknown";
1060 LOG(ERROR) << histogram_tag_ << " sqlite error " << err
1061 << ", errno " << GetLastErrno()
1062 << ": " << GetErrorMessage()
1063 << ", sql: " << sql;
1065 if (!error_callback_.is_null()) {
1066 // Fire from a copy of the callback in case of reentry into
1067 // re/set_error_callback().
1068 // TODO(shess): <http://crbug.com/254584>
1069 ErrorCallback(error_callback_).Run(err, stmt);
1070 return err;
1073 // The default handling is to assert on debug and to ignore on release.
1074 if (!ShouldIgnoreSqliteError(err))
1075 DLOG(FATAL) << GetErrorMessage();
1076 return err;
1079 bool Connection::FullIntegrityCheck(std::vector<std::string>* messages) {
1080 return IntegrityCheckHelper("PRAGMA integrity_check", messages);
1083 bool Connection::QuickIntegrityCheck() {
1084 std::vector<std::string> messages;
1085 if (!IntegrityCheckHelper("PRAGMA quick_check", &messages))
1086 return false;
1087 return messages.size() == 1 && messages[0] == "ok";
1090 // TODO(shess): Allow specifying maximum results (default 100 lines).
1091 bool Connection::IntegrityCheckHelper(
1092 const char* pragma_sql,
1093 std::vector<std::string>* messages) {
1094 messages->clear();
1096 // This has the side effect of setting SQLITE_RecoveryMode, which
1097 // allows SQLite to process through certain cases of corruption.
1098 // Failing to set this pragma probably means that the database is
1099 // beyond recovery.
1100 const char kWritableSchema[] = "PRAGMA writable_schema = ON";
1101 if (!Execute(kWritableSchema))
1102 return false;
1104 bool ret = false;
1106 sql::Statement stmt(GetUniqueStatement(pragma_sql));
1108 // The pragma appears to return all results (up to 100 by default)
1109 // as a single string. This doesn't appear to be an API contract,
1110 // it could return separate lines, so loop _and_ split.
1111 while (stmt.Step()) {
1112 std::string result(stmt.ColumnString(0));
1113 base::SplitString(result, '\n', messages);
1115 ret = stmt.Succeeded();
1118 // Best effort to put things back as they were before.
1119 const char kNoWritableSchema[] = "PRAGMA writable_schema = OFF";
1120 ignore_result(Execute(kNoWritableSchema));
1122 return ret;
1125 } // namespace sql