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Diffstat (limited to 'utils/sqlite/database.cpp')
| -rw-r--r-- | utils/sqlite/database.cpp | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/utils/sqlite/database.cpp b/utils/sqlite/database.cpp new file mode 100644 index 000000000000..41935c3b017d --- /dev/null +++ b/utils/sqlite/database.cpp @@ -0,0 +1,328 @@ +// Copyright 2011 The Kyua Authors. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// * Neither the name of Google Inc. nor the names of its contributors +// may be used to endorse or promote products derived from this software +// without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include "utils/sqlite/database.hpp" + +extern "C" { +#include <sqlite3.h> +} + +#include <cstring> +#include <stdexcept> + +#include "utils/format/macros.hpp" +#include "utils/fs/path.hpp" +#include "utils/logging/macros.hpp" +#include "utils/noncopyable.hpp" +#include "utils/optional.ipp" +#include "utils/sanity.hpp" +#include "utils/sqlite/exceptions.hpp" +#include "utils/sqlite/statement.ipp" +#include "utils/sqlite/transaction.hpp" + +namespace fs = utils::fs; +namespace sqlite = utils::sqlite; + +using utils::none; +using utils::optional; + + +/// Internal implementation for sqlite::database. +struct utils::sqlite::database::impl : utils::noncopyable { + /// Path to the database as seen at construction time. + optional< fs::path > db_filename; + + /// The SQLite 3 internal database. + ::sqlite3* db; + + /// Whether we own the database or not (to decide if we close it). + bool owned; + + /// Constructor. + /// + /// \param db_filename_ The path to the database as seen at construction + /// time, if any, or none for in-memory databases. We should use + /// sqlite3_db_filename instead, but this function appeared in 3.7.10 + /// and Ubuntu 12.04 LTS (which we support for Travis CI builds as of + /// 2015-07-07) ships with 3.7.9. + /// \param db_ The SQLite internal database. + /// \param owned_ Whether this object owns the db_ object or not. If it + /// does, the internal db_ will be released during destruction. + impl(optional< fs::path > db_filename_, ::sqlite3* db_, const bool owned_) : + db_filename(db_filename_), db(db_), owned(owned_) + { + } + + /// Destructor. + /// + /// It is important to keep this as part of the 'impl' class instead of the + /// container class. The 'impl' class is destroyed exactly once (because it + /// is managed by a shared_ptr) and thus releasing the resources here is + /// OK. However, the container class is potentially released many times, + /// which means that we would be double-freeing the internal object and + /// reusing invalid data. + ~impl(void) + { + if (owned && db != NULL) + close(); + } + + /// Exception-safe version of sqlite3_open_v2. + /// + /// \param file The path to the database file to be opened. + /// \param flags The flags to be passed to the open routine. + /// + /// \return The opened database. + /// + /// \throw std::bad_alloc If there is not enough memory to open the + /// database. + /// \throw api_error If there is any problem opening the database. + static ::sqlite3* + safe_open(const char* file, const int flags) + { + ::sqlite3* db; + const int error = ::sqlite3_open_v2(file, &db, flags, NULL); + if (error != SQLITE_OK) { + if (db == NULL) + throw std::bad_alloc(); + else { + sqlite::database error_db(utils::make_optional(fs::path(file)), + db, true); + throw sqlite::api_error::from_database(error_db, + "sqlite3_open_v2"); + } + } + INV(db != NULL); + return db; + } + + /// Shared code for the public close() method. + void + close(void) + { + PRE(db != NULL); + int error = ::sqlite3_close(db); + // For now, let's consider a return of SQLITE_BUSY an error. We should + // not be trying to close a busy database in our code. Maybe revisit + // this later to raise busy errors as exceptions. + PRE(error == SQLITE_OK); + db = NULL; + } +}; + + +/// Initializes the SQLite database. +/// +/// You must share the same database object alongside the lifetime of your +/// SQLite session. As soon as the object is destroyed, the session is +/// terminated. +/// +/// \param db_filename_ The path to the database as seen at construction +/// time, if any, or none for in-memory databases. +/// \param db_ Raw pointer to the C SQLite 3 object. +/// \param owned_ Whether this instance will own the pointer or not. +sqlite::database::database( + const utils::optional< utils::fs::path >& db_filename_, void* db_, + const bool owned_) : + _pimpl(new impl(db_filename_, static_cast< ::sqlite3* >(db_), owned_)) +{ +} + + +/// Destructor for the SQLite 3 database. +/// +/// Closes the session unless it has already been closed by calling the +/// close() method. It is recommended to explicitly close the session in the +/// code. +sqlite::database::~database(void) +{ +} + + +/// Opens a memory-based temporary SQLite database. +/// +/// \return An in-memory database instance. +/// +/// \throw std::bad_alloc If there is not enough memory to open the database. +/// \throw api_error If there is any problem opening the database. +sqlite::database +sqlite::database::in_memory(void) +{ + return database(none, impl::safe_open(":memory:", SQLITE_OPEN_READWRITE), + true); +} + + +/// Opens a named on-disk SQLite database. +/// +/// \param file The path to the database file to be opened. This does not +/// accept the values "" and ":memory:"; use temporary() and in_memory() +/// instead. +/// \param open_flags The flags to be passed to the open routine. +/// +/// \return A file-backed database instance. +/// +/// \throw std::bad_alloc If there is not enough memory to open the database. +/// \throw api_error If there is any problem opening the database. +sqlite::database +sqlite::database::open(const fs::path& file, int open_flags) +{ + PRE_MSG(!file.str().empty(), "Use database::temporary() instead"); + PRE_MSG(file.str() != ":memory:", "Use database::in_memory() instead"); + + int flags = 0; + if (open_flags & open_readonly) { + flags |= SQLITE_OPEN_READONLY; + open_flags &= ~open_readonly; + } + if (open_flags & open_readwrite) { + flags |= SQLITE_OPEN_READWRITE; + open_flags &= ~open_readwrite; + } + if (open_flags & open_create) { + flags |= SQLITE_OPEN_CREATE; + open_flags &= ~open_create; + } + PRE(open_flags == 0); + + return database(utils::make_optional(file), + impl::safe_open(file.c_str(), flags), true); +} + + +/// Opens an unnamed on-disk SQLite database. +/// +/// \return A file-backed database instance. +/// +/// \throw std::bad_alloc If there is not enough memory to open the database. +/// \throw api_error If there is any problem opening the database. +sqlite::database +sqlite::database::temporary(void) +{ + return database(none, impl::safe_open("", SQLITE_OPEN_READWRITE), true); +} + + +/// Gets the internal sqlite3 object. +/// +/// \return The raw SQLite 3 database. This is returned as a void pointer to +/// prevent including the sqlite3.h header file from our public interface. The +/// only way to call this method is by using the c_gate module, and c_gate takes +/// care of casting this object to the appropriate type. +void* +sqlite::database::raw_database(void) +{ + return _pimpl->db; +} + + +/// Terminates the connection to the database. +/// +/// It is recommended to call this instead of relying on the destructor to do +/// the cleanup, but it is not a requirement to use close(). +/// +/// \pre close() has not yet been called. +void +sqlite::database::close(void) +{ + _pimpl->close(); +} + + +/// Returns the path to the connected database. +/// +/// It is OK to call this function on a live database object, even after close() +/// has been called. The returned value is consistent at all times. +/// +/// \return The path to the file that matches the connected database or none if +/// the connection points to a transient database. +const optional< fs::path >& +sqlite::database::db_filename(void) const +{ + return _pimpl->db_filename; +} + + +/// Executes an arbitrary SQL string. +/// +/// As the documentation explains, this is unsafe. The code should really be +/// preparing statements and executing them step by step. However, it is +/// perfectly fine to use this function for, e.g. the initial creation of +/// tables in a database and in tests. +/// +/// \param sql The SQL commands to be executed. +/// +/// \throw api_error If there is any problem while processing the SQL. +void +sqlite::database::exec(const std::string& sql) +{ + const int error = ::sqlite3_exec(_pimpl->db, sql.c_str(), NULL, NULL, NULL); + if (error != SQLITE_OK) + throw api_error::from_database(*this, "sqlite3_exec"); +} + + +/// Opens a new transaction. +/// +/// \return An object representing the state of the transaction. +/// +/// \throw api_error If there is any problem while opening the transaction. +sqlite::transaction +sqlite::database::begin_transaction(void) +{ + exec("BEGIN TRANSACTION"); + return transaction(*this); +} + + +/// Prepares a new statement. +/// +/// \param sql The SQL statement to prepare. +/// +/// \return The prepared statement. +sqlite::statement +sqlite::database::create_statement(const std::string& sql) +{ + LD(F("Creating statement: %s") % sql); + sqlite3_stmt* stmt; + const int error = ::sqlite3_prepare_v2(_pimpl->db, sql.c_str(), + sql.length() + 1, &stmt, NULL); + if (error != SQLITE_OK) + throw api_error::from_database(*this, "sqlite3_prepare_v2"); + return statement(*this, static_cast< void* >(stmt)); +} + + +/// Returns the row identifier of the last insert. +/// +/// \return A row identifier. +int64_t +sqlite::database::last_insert_rowid(void) +{ + return ::sqlite3_last_insert_rowid(_pimpl->db); +} |