2024-03-19 17:45:12 +08:00

294 lines
11 KiB
C++

/**
* @file Database.cpp
* @ingroup SQLiteCpp
* @brief Management of a SQLite Database Connection.
*
* Copyright (c) 2012-2018 Sebastien Rombauts (sebastien.rombauts@gmail.com)
*
* Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
* or copy at http://opensource.org/licenses/MIT)
*/
#include "Database.h"
#include "Statement.h"
#include "Assertion.h"
#include "Exception.h"
#include "sqlite3.h"
#include <fstream>
#include <string.h>
#ifndef SQLITE_DETERMINISTIC
#define SQLITE_DETERMINISTIC 0x800
#endif // SQLITE_DETERMINISTIC
namespace SQLite
{
const int OPEN_READONLY = SQLITE_OPEN_READONLY;
const int OPEN_READWRITE = SQLITE_OPEN_READWRITE;
const int OPEN_CREATE = SQLITE_OPEN_CREATE;
const int OPEN_URI = SQLITE_OPEN_URI;
const int OK = SQLITE_OK;
const char* VERSION = SQLITE_VERSION;
const int VERSION_NUMBER = SQLITE_VERSION_NUMBER;
// Return SQLite version string using runtime call to the compiled library
const char* getLibVersion() noexcept // nothrow
{
return sqlite3_libversion();
}
// Return SQLite version number using runtime call to the compiled library
int getLibVersionNumber() noexcept // nothrow
{
return sqlite3_libversion_number();
}
// Open the provided database UTF-8 filename with SQLite::OPEN_xxx provided flags.
Database::Database(const char* apFilename,
const int aFlags /* = SQLite::OPEN_READONLY*/,
const int aBusyTimeoutMs /* = 0 */,
const char* apVfs /* = nullptr*/) :
mpSQLite(nullptr),
mFilename(apFilename)
{
const int ret = sqlite3_open_v2(apFilename, &mpSQLite, aFlags, apVfs);
if (SQLITE_OK != ret)
{
const SQLite::Exception exception(mpSQLite, ret); // must create before closing
sqlite3_close(mpSQLite); // close is required even in case of error on opening
throw exception;
}
if (aBusyTimeoutMs > 0)
{
setBusyTimeout(aBusyTimeoutMs);
}
}
// Open the provided database UTF-8 filename with SQLite::OPEN_xxx provided flags.
Database::Database(const std::string& aFilename,
const int aFlags /* = SQLite::OPEN_READONLY*/,
const int aBusyTimeoutMs /* = 0 */,
const std::string& aVfs /* = "" */) :
mpSQLite(nullptr),
mFilename(aFilename)
{
const int ret = sqlite3_open_v2(aFilename.c_str(), &mpSQLite, aFlags, aVfs.empty() ? nullptr : aVfs.c_str());
if (SQLITE_OK != ret)
{
const SQLite::Exception exception(mpSQLite, ret); // must create before closing
sqlite3_close(mpSQLite); // close is required even in case of error on opening
throw exception;
}
if (aBusyTimeoutMs > 0)
{
setBusyTimeout(aBusyTimeoutMs);
}
}
// Close the SQLite database connection.
Database::~Database()
{
const int ret = sqlite3_close(mpSQLite);
// Avoid unreferenced variable warning when build in release mode
(void) ret;
// Only case of error is SQLITE_BUSY: "database is locked" (some statements are not finalized)
// Never throw an exception in a destructor :
SQLITECPP_ASSERT(SQLITE_OK == ret, "database is locked"); // See SQLITECPP_ENABLE_ASSERT_HANDLER
}
/**
* @brief Set a busy handler that sleeps for a specified amount of time when a table is locked.
*
* This is useful in multithreaded program to handle case where a table is locked for writting by a thread.
* Any other thread cannot access the table and will receive a SQLITE_BUSY error:
* setting a timeout will wait and retry up to the time specified before returning this SQLITE_BUSY error.
* Reading the value of timeout for current connection can be done with SQL query "PRAGMA busy_timeout;".
* Default busy timeout is 0ms.
*
* @param[in] aBusyTimeoutMs Amount of milliseconds to wait before returning SQLITE_BUSY
*
* @throw SQLite::Exception in case of error
*/
void Database::setBusyTimeout(const int aBusyTimeoutMs)
{
const int ret = sqlite3_busy_timeout(mpSQLite, aBusyTimeoutMs);
check(ret);
}
// Shortcut to execute one or multiple SQL statements without results (UPDATE, INSERT, ALTER, COMMIT, CREATE...).
int Database::exec(const char* apQueries)
{
const int ret = sqlite3_exec(mpSQLite, apQueries, nullptr, nullptr, nullptr);
check(ret);
// Return the number of rows modified by those SQL statements (INSERT, UPDATE or DELETE only)
return sqlite3_changes(mpSQLite);
}
// Shortcut to execute a one step query and fetch the first column of the result.
// WARNING: Be very careful with this dangerous method: you have to
// make a COPY OF THE result, else it will be destroy before the next line
// (when the underlying temporary Statement and Column objects are destroyed)
// this is an issue only for pointer type result (ie. char* and blob)
// (use the Column copy-constructor)
Column Database::execAndGet(const char* apQuery)
{
Statement query(*this, apQuery);
(void)query.executeStep(); // Can return false if no result, which will throw next line in getColumn()
return query.getColumn(0);
}
// Shortcut to test if a table exists.
bool Database::tableExists(const char* apTableName)
{
Statement query(*this, "SELECT count(*) FROM sqlite_master WHERE type='table' AND name=?");
query.bind(1, apTableName);
(void)query.executeStep(); // Cannot return false, as the above query always return a result
return (1 == query.getColumn(0).getInt());
}
// Get the rowid of the most recent successful INSERT into the database from the current connection.
long long Database::getLastInsertRowid() const noexcept // nothrow
{
return sqlite3_last_insert_rowid(mpSQLite);
}
// Get total number of rows modified by all INSERT, UPDATE or DELETE statement since connection.
int Database::getTotalChanges() const noexcept // nothrow
{
return sqlite3_total_changes(mpSQLite);
}
// Return the numeric result code for the most recent failed API call (if any).
int Database::getErrorCode() const noexcept // nothrow
{
return sqlite3_errcode(mpSQLite);
}
// Return the extended numeric result code for the most recent failed API call (if any).
int Database::getExtendedErrorCode() const noexcept // nothrow
{
return sqlite3_extended_errcode(mpSQLite);
}
// Return UTF-8 encoded English language explanation of the most recent failed API call (if any).
const char* Database::getErrorMsg() const noexcept // nothrow
{
return sqlite3_errmsg(mpSQLite);
}
// Attach a custom function to your sqlite database. Assumes UTF8 text representation.
// Parameter details can be found here: http://www.sqlite.org/c3ref/create_function.html
void Database::createFunction(const char* apFuncName,
int aNbArg,
bool abDeterministic,
void* apApp,
void (*apFunc)(sqlite3_context *, int, sqlite3_value **),
void (*apStep)(sqlite3_context *, int, sqlite3_value **),
void (*apFinal)(sqlite3_context *), // NOLINT(readability/casting)
void (*apDestroy)(void *))
{
int TextRep = SQLITE_UTF8;
// optimization if deterministic function (e.g. of nondeterministic function random())
if (abDeterministic) {
TextRep = TextRep|SQLITE_DETERMINISTIC;
}
const int ret = sqlite3_create_function_v2(mpSQLite, apFuncName, aNbArg, TextRep,
apApp, apFunc, apStep, apFinal, apDestroy);
check(ret);
}
// Load an extension into the sqlite database. Only affects the current connection.
// Parameter details can be found here: http://www.sqlite.org/c3ref/load_extension.html
void Database::loadExtension(const char* apExtensionName, const char *apEntryPointName)
{
#ifdef SQLITE_OMIT_LOAD_EXTENSION
// Unused
(void)apExtensionName;
(void)apEntryPointName;
throw std::runtime_error("sqlite extensions are disabled");
#else
#ifdef SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION // Since SQLite 3.13 (2016-05-18):
// Security warning:
// It is recommended that the SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION method be used to enable only this interface.
// The use of the sqlite3_enable_load_extension() interface should be avoided to keep the SQL load_extension()
// disabled and prevent SQL injections from giving attackers access to extension loading capabilities.
// (NOTE: not using nullptr: cannot pass object of non-POD type 'std::__1::nullptr_t' through variadic function)
int ret = sqlite3_db_config(mpSQLite, SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, 1, NULL); // NOTE: not using nullptr
#else
int ret = sqlite3_enable_load_extension(mpSQLite, 1);
#endif
check(ret);
ret = sqlite3_load_extension(mpSQLite, apExtensionName, apEntryPointName, 0);
check(ret);
#endif
}
// Set the key for the current sqlite database instance.
void Database::key(const std::string& aKey) const
{
int pass_len = static_cast<int>(aKey.length());
#ifdef SQLITE_HAS_CODEC
if (pass_len > 0) {
const int ret = sqlite3_key(mpSQLite, aKey.c_str(), pass_len);
check(ret);
}
#else // SQLITE_HAS_CODEC
if (pass_len > 0) {
const SQLite::Exception exception("No encryption support, recompile with SQLITE_HAS_CODEC to enable.");
throw exception;
}
#endif // SQLITE_HAS_CODEC
}
// Reset the key for the current sqlite database instance.
void Database::rekey(const std::string& aNewKey) const
{
#ifdef SQLITE_HAS_CODEC
int pass_len = aNewKey.length();
if (pass_len > 0) {
const int ret = sqlite3_rekey(mpSQLite, aNewKey.c_str(), pass_len);
check(ret);
} else {
const int ret = sqlite3_rekey(mpSQLite, nullptr, 0);
check(ret);
}
#else // SQLITE_HAS_CODEC
static_cast<void>(aNewKey); // silence unused parameter warning
const SQLite::Exception exception("No encryption support, recompile with SQLITE_HAS_CODEC to enable.");
throw exception;
#endif // SQLITE_HAS_CODEC
}
// Test if a file contains an unencrypted database.
bool Database::isUnencrypted(const std::string& aFilename)
{
if (aFilename.length() > 0) {
std::ifstream fileBuffer(aFilename.c_str(), std::ios::in | std::ios::binary);
char header[16];
if (fileBuffer.is_open()) {
fileBuffer.seekg(0, std::ios::beg);
fileBuffer.getline(header, 16);
fileBuffer.close();
} else {
const SQLite::Exception exception("Error opening file: " + aFilename);
throw exception;
}
return strncmp(header, "SQLite format 3\000", 16) == 0;
}
const SQLite::Exception exception("Could not open database, the aFilename parameter was empty.");
throw exception;
}
} // namespace SQLite