blob: 111fde642b4e170c505a318d348f2e4b409aa96b [file] [log] [blame]
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "app/sql/connection.h"
#include <string.h>
#include "app/sql/statement.h"
#include "base/file_path.h"
#include "base/logging.h"
#include "base/string_util.h"
#include "base/utf_string_conversions.h"
#ifdef ANDROID
#include "sqlite3.h"
#else
#include "third_party/sqlite/sqlite3.h"
#endif
namespace {
// Spin for up to a second waiting for the lock to clear when setting
// up the database.
// TODO(shess): Better story on this. http://crbug.com/56559
const base::TimeDelta kBusyTimeout = base::TimeDelta::FromSeconds(1);
class ScopedBusyTimeout {
public:
explicit ScopedBusyTimeout(sqlite3* db)
: db_(db) {
}
~ScopedBusyTimeout() {
sqlite3_busy_timeout(db_, 0);
}
int SetTimeout(base::TimeDelta timeout) {
DCHECK_LT(timeout.InMilliseconds(), INT_MAX);
return sqlite3_busy_timeout(db_,
static_cast<int>(timeout.InMilliseconds()));
}
private:
sqlite3* db_;
};
} // namespace
namespace sql {
bool StatementID::operator<(const StatementID& other) const {
if (number_ != other.number_)
return number_ < other.number_;
return strcmp(str_, other.str_) < 0;
}
ErrorDelegate::ErrorDelegate() {
}
ErrorDelegate::~ErrorDelegate() {
}
Connection::StatementRef::StatementRef()
: connection_(NULL),
stmt_(NULL) {
}
Connection::StatementRef::StatementRef(Connection* connection,
sqlite3_stmt* stmt)
: connection_(connection),
stmt_(stmt) {
connection_->StatementRefCreated(this);
}
Connection::StatementRef::~StatementRef() {
if (connection_)
connection_->StatementRefDeleted(this);
Close();
}
void Connection::StatementRef::Close() {
if (stmt_) {
sqlite3_finalize(stmt_);
stmt_ = NULL;
}
connection_ = NULL; // The connection may be getting deleted.
}
Connection::Connection()
: db_(NULL),
page_size_(0),
cache_size_(0),
exclusive_locking_(false),
transaction_nesting_(0),
needs_rollback_(false) {
}
Connection::~Connection() {
Close();
}
bool Connection::Open(const FilePath& path) {
#if defined(OS_WIN)
return OpenInternal(WideToUTF8(path.value()));
#elif defined(OS_POSIX)
return OpenInternal(path.value());
#endif
}
bool Connection::OpenInMemory() {
return OpenInternal(":memory:");
}
void Connection::Close() {
statement_cache_.clear();
DCHECK(open_statements_.empty());
if (db_) {
sqlite3_close(db_);
db_ = NULL;
}
}
void Connection::Preload() {
if (!db_) {
NOTREACHED();
return;
}
// A statement must be open for the preload command to work. If the meta
// table doesn't exist, it probably means this is a new database and there
// is nothing to preload (so it's OK we do nothing).
if (!DoesTableExist("meta"))
return;
Statement dummy(GetUniqueStatement("SELECT * FROM meta"));
if (!dummy || !dummy.Step())
return;
#if !defined(USE_SYSTEM_SQLITE)
// This function is only defined in Chromium's version of sqlite.
// Do not call it when using system sqlite.
sqlite3_preload(db_);
#endif
}
bool Connection::BeginTransaction() {
if (needs_rollback_) {
DCHECK_GT(transaction_nesting_, 0);
// When we're going to rollback, fail on this begin and don't actually
// mark us as entering the nested transaction.
return false;
}
bool success = true;
if (!transaction_nesting_) {
needs_rollback_ = false;
Statement begin(GetCachedStatement(SQL_FROM_HERE, "BEGIN TRANSACTION"));
if (!begin || !begin.Run())
return false;
}
transaction_nesting_++;
return success;
}
void Connection::RollbackTransaction() {
if (!transaction_nesting_) {
NOTREACHED() << "Rolling back a nonexistent transaction";
return;
}
transaction_nesting_--;
if (transaction_nesting_ > 0) {
// Mark the outermost transaction as needing rollback.
needs_rollback_ = true;
return;
}
DoRollback();
}
bool Connection::CommitTransaction() {
if (!transaction_nesting_) {
NOTREACHED() << "Rolling back a nonexistent transaction";
return false;
}
transaction_nesting_--;
if (transaction_nesting_ > 0) {
// Mark any nested transactions as failing after we've already got one.
return !needs_rollback_;
}
if (needs_rollback_) {
DoRollback();
return false;
}
Statement commit(GetCachedStatement(SQL_FROM_HERE, "COMMIT"));
if (!commit)
return false;
return commit.Run();
}
bool Connection::Execute(const char* sql) {
if (!db_)
return false;
return sqlite3_exec(db_, sql, NULL, NULL, NULL) == SQLITE_OK;
}
bool Connection::ExecuteWithTimeout(const char* sql, base::TimeDelta timeout) {
if (!db_)
return false;
ScopedBusyTimeout busy_timeout(db_);
busy_timeout.SetTimeout(timeout);
return sqlite3_exec(db_, sql, NULL, NULL, NULL) == SQLITE_OK;
}
bool Connection::HasCachedStatement(const StatementID& id) const {
return statement_cache_.find(id) != statement_cache_.end();
}
scoped_refptr<Connection::StatementRef> Connection::GetCachedStatement(
const StatementID& id,
const char* sql) {
CachedStatementMap::iterator i = statement_cache_.find(id);
if (i != statement_cache_.end()) {
// Statement is in the cache. It should still be active (we're the only
// one invalidating cached statements, and we'll remove it from the cache
// if we do that. Make sure we reset it before giving out the cached one in
// case it still has some stuff bound.
DCHECK(i->second->is_valid());
sqlite3_reset(i->second->stmt());
return i->second;
}
scoped_refptr<StatementRef> statement = GetUniqueStatement(sql);
if (statement->is_valid())
statement_cache_[id] = statement; // Only cache valid statements.
return statement;
}
scoped_refptr<Connection::StatementRef> Connection::GetUniqueStatement(
const char* sql) {
if (!db_)
return new StatementRef(this, NULL); // Return inactive statement.
sqlite3_stmt* stmt = NULL;
if (sqlite3_prepare_v2(db_, sql, -1, &stmt, NULL) != SQLITE_OK) {
// Treat this as non-fatal, it can occur in a number of valid cases, and
// callers should be doing their own error handling.
DLOG(WARNING) << "SQL compile error " << GetErrorMessage();
return new StatementRef(this, NULL);
}
return new StatementRef(this, stmt);
}
bool Connection::DoesTableExist(const char* table_name) const {
// GetUniqueStatement can't be const since statements may modify the
// database, but we know ours doesn't modify it, so the cast is safe.
Statement statement(const_cast<Connection*>(this)->GetUniqueStatement(
"SELECT name FROM sqlite_master "
"WHERE type='table' AND name=?"));
if (!statement)
return false;
statement.BindString(0, table_name);
return statement.Step(); // Table exists if any row was returned.
}
bool Connection::DoesColumnExist(const char* table_name,
const char* column_name) const {
std::string sql("PRAGMA TABLE_INFO(");
sql.append(table_name);
sql.append(")");
// Our SQL is non-mutating, so this cast is OK.
Statement statement(const_cast<Connection*>(this)->GetUniqueStatement(
sql.c_str()));
if (!statement)
return false;
while (statement.Step()) {
if (!statement.ColumnString(1).compare(column_name))
return true;
}
return false;
}
int64 Connection::GetLastInsertRowId() const {
if (!db_) {
NOTREACHED();
return 0;
}
return sqlite3_last_insert_rowid(db_);
}
int Connection::GetLastChangeCount() const {
if (!db_) {
NOTREACHED();
return 0;
}
return sqlite3_changes(db_);
}
int Connection::GetErrorCode() const {
if (!db_)
return SQLITE_ERROR;
return sqlite3_errcode(db_);
}
int Connection::GetLastErrno() const {
if (!db_)
return -1;
int err = 0;
if (SQLITE_OK != sqlite3_file_control(db_, NULL, SQLITE_LAST_ERRNO, &err))
return -2;
return err;
}
const char* Connection::GetErrorMessage() const {
if (!db_)
return "sql::Connection has no connection.";
return sqlite3_errmsg(db_);
}
bool Connection::OpenInternal(const std::string& file_name) {
if (db_) {
NOTREACHED() << "sql::Connection is already open.";
return false;
}
int err = sqlite3_open(file_name.c_str(), &db_);
if (err != SQLITE_OK) {
OnSqliteError(err, NULL);
db_ = NULL;
return false;
}
// Enable extended result codes to provide more color on I/O errors.
// Not having extended result codes is not a fatal problem, as
// Chromium code does not attempt to handle I/O errors anyhow. The
// current implementation always returns SQLITE_OK, the DCHECK is to
// quickly notify someone if SQLite changes.
err = sqlite3_extended_result_codes(db_, 1);
DCHECK_EQ(err, SQLITE_OK) << "Could not enable extended result codes";
// If indicated, lock up the database before doing anything else, so
// that the following code doesn't have to deal with locking.
// TODO(shess): This code is brittle. Find the cases where code
// doesn't request |exclusive_locking_| and audit that it does the
// right thing with SQLITE_BUSY, and that it doesn't make
// assumptions about who might change things in the database.
// http://crbug.com/56559
if (exclusive_locking_) {
// TODO(shess): This should probably be a full CHECK(). Code
// which requests exclusive locking but doesn't get it is almost
// certain to be ill-tested.
if (!Execute("PRAGMA locking_mode=EXCLUSIVE"))
NOTREACHED() << "Could not set locking mode: " << GetErrorMessage();
}
if (page_size_ != 0) {
// Enforce SQLite restrictions on |page_size_|.
DCHECK(!(page_size_ & (page_size_ - 1)))
<< " page_size_ " << page_size_ << " is not a power of two.";
static const int kSqliteMaxPageSize = 32768; // from sqliteLimit.h
DCHECK_LE(page_size_, kSqliteMaxPageSize);
const std::string sql = StringPrintf("PRAGMA page_size=%d", page_size_);
if (!ExecuteWithTimeout(sql.c_str(), kBusyTimeout))
NOTREACHED() << "Could not set page size: " << GetErrorMessage();
}
if (cache_size_ != 0) {
const std::string sql = StringPrintf("PRAGMA cache_size=%d", cache_size_);
if (!ExecuteWithTimeout(sql.c_str(), kBusyTimeout))
NOTREACHED() << "Could not set cache size: " << GetErrorMessage();
}
return true;
}
void Connection::DoRollback() {
Statement rollback(GetCachedStatement(SQL_FROM_HERE, "ROLLBACK"));
if (rollback)
rollback.Run();
}
void Connection::StatementRefCreated(StatementRef* ref) {
DCHECK(open_statements_.find(ref) == open_statements_.end());
open_statements_.insert(ref);
}
void Connection::StatementRefDeleted(StatementRef* ref) {
StatementRefSet::iterator i = open_statements_.find(ref);
if (i == open_statements_.end())
NOTREACHED();
else
open_statements_.erase(i);
}
void Connection::ClearCache() {
statement_cache_.clear();
// The cache clear will get most statements. There may be still be references
// to some statements that are held by others (including one-shot statements).
// This will deactivate them so they can't be used again.
for (StatementRefSet::iterator i = open_statements_.begin();
i != open_statements_.end(); ++i)
(*i)->Close();
}
int Connection::OnSqliteError(int err, sql::Statement *stmt) {
if (error_delegate_.get())
return error_delegate_->OnError(err, this, stmt);
// The default handling is to assert on debug and to ignore on release.
NOTREACHED() << GetErrorMessage();
return err;
}
} // namespace sql