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Diffstat (limited to 'external/glim/sqlite.hpp')
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diff --git a/external/glim/sqlite.hpp b/external/glim/sqlite.hpp deleted file mode 100644 index c7e92ac4a..000000000 --- a/external/glim/sqlite.hpp +++ /dev/null @@ -1,538 +0,0 @@ -#ifndef GLIM_SQLITE_HPP_ -#define GLIM_SQLITE_HPP_ - -/** - * A threaded interface to <a href="http://sqlite.org/">SQLite</a>. - * This file is a header-only library, - * whose sole dependencies should be standard STL and posix threading libraries. - * You can extract this file out of the "glim" library to include it separately in your project. - * @code -Copyright 2006-2012 Kozarezov Artem Aleksandrovich - -Licensed under the Apache License, Version 2.0 (the "License"); -you may not use this file except in compliance with the License. -You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - -Unless required by applicable law or agreed to in writing, software -distributed under the License is distributed on an "AS IS" BASIS, -WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -See the License for the specific language governing permissions and -limitations under the License. - * @endcode - * @file - */ - -#include <stdexcept> -#include <string> -#include <sqlite3.h> -#include <pthread.h> -#include <string.h> // strerror -#include <sys/types.h> // stat -#include <sys/stat.h> // stat -#include <unistd.h> // stat -#include <errno.h> // stat -#include <stdio.h> // snprintf -#include <stdint.h> - -namespace glim { - -class SqliteSession; -class SqliteQuery; - -struct SqliteEx: public std::runtime_error { - SqliteEx (const std::string& what): std::runtime_error (what) {} -}; - -/** - * The database. - * According to sqlite3_open <a href="http://sqlite.org/capi3ref.html#sqlite3_open">documentation</a>, - * only the thread that opened the database can safely access it. This restriction was - * relaxed, as described in the <a href="http://www.sqlite.org/faq.html#q8">FAQ</a> - * (the "Is SQLite threadsafe?" question), so we can use the library from multiple - * threads, but only if no more than one thread at a time accesses the database. - * This restriction is, in fact, beneficial if the database is used from a single application: - * by restricting access to a sigle thread at a time, we effectively avoid all deadlock issues.\n - * This library goals are:\n - * \li to ensure that SQLite is used in a thread-safe way, - * \li to provide additional threaded quirks, such as delayed updates (not implemented). - * - * The library is targeted at SQLite setup which is \b not \c -DTHREADSAFE, - * since this is the default setup on UNIX architectures.\n - * \n - * This file is a header-only library, - * whose sole dependencies should be standard STL and posix threading libraries. - * You can extract this file out of the "glim" library to include it separately in your project.\n - * \n - * This library is targeted at UTF-8 API. There is no plans to support the UTF-16 API.\n - * \n - * See also:\n - * \li http://www.sqlite.org/cvstrac/fileview?f=sqlite/src/server.c\n - * for another way of handling multithreading with SQLite. - */ -class Sqlite { - /// No copying allowed. - Sqlite& operator = (const Sqlite& other) {return *this;} - /// No copying allowed. - Sqlite (const Sqlite& other) = delete; - friend class SqliteSession; - protected: - /// Filename the database was opened with; we need it to reopen the database on fork()s. - /// std::string is used to avoid memory allocation issues. - std::string filename; - ::sqlite3* handler; - ::pthread_mutex_t mutex; - public: - /// Flags for the Sqlite constructor. - enum Flags { - /** - * The file will be checked for existence. - * SqliteEx is thrown if the file is not accessible; - * format of the error description is "$filename: $strerror".\n - * Usage example: \code Sqlite db ("filename", Sqlite::existing); \endcode - */ - existing = 1 - }; - /** - * Opens the database. - * @param filename Database filename (UTF-8). - * @param flags Optional. Currently there is the #existing flag. - * @throws SqliteEx Thrown if we can't open the database. - */ - Sqlite (std::string filename, int flags = 0) { - if (flags & existing) { - // Check if the file exists already. - struct stat st; if (stat (filename.c_str(), &st)) - throw SqliteEx (filename + ": " + ::strerror(errno)); - } - ::pthread_mutex_init (&mutex, NULL); - this->filename = filename; - if (::sqlite3_open(filename.c_str(), &handler) != SQLITE_OK) - throw SqliteEx (std::string("sqlite3_open(") + filename + "): " + ::sqlite3_errmsg(handler)); - } - /** - * Closes the database. - * @throws SqliteEx Thrown if we can't close the database. - */ - ~Sqlite () { - ::pthread_mutex_destroy (&mutex); - if (::sqlite3_close(handler) != SQLITE_OK) - throw SqliteEx (std::string ("sqlite3_close(): ") + ::sqlite3_errmsg(handler)); - } - - Sqlite& exec (const char* query); - /** - * Invokes `exec` on `query.c_str()`. - * Example:\code - * glim::Sqlite sqlite (":memory:"); - * for (std::string pv: {"page_size = 4096", "secure_delete = 1"}) sqlite->exec2 ("PRAGMA " + pv); \endcode - */ - template <typename StringLike> Sqlite& exec2 (StringLike query) {return exec (query.c_str());} -}; - -/** - * A single thread session with Sqlite. - * Only a sigle thread at a time can have an SqliteSession, - * all other threads will wait, in the SqliteSession constructor, - * till the active session is either closed or destructed. - */ -class SqliteSession { - /// No copying allowed. - SqliteSession& operator = (const SqliteSession& other) {return *this;} - /// No copying allowed. - SqliteSession(SqliteSession& other): db (NULL) {} - protected: - Sqlite* db; - public: - /** - * Locks the database. - * @throws SqliteEx if a mutex error occurs. - */ - SqliteSession (Sqlite* sqlite): db (sqlite) { - int err = ::pthread_mutex_lock (&(db->mutex)); - if (err != 0) throw SqliteEx (std::string ("error locking the mutex: ") + ::strerror(err)); - } - /** - * A shorter way to construct query from the session. - * Usage example: \code ses.query(S("create table test (i integer)")).step() \endcode - * @see SqliteQuery#qstep - */ - template <typename T> - SqliteQuery query (T t); - /// Automatically unlocks the database. - /// @see close - ~SqliteSession () {close();} - /** - * Unlock the database. - * It is safe to call this method multiple times.\n - * You must not use the session after it was closed.\n - * All resources allocated within this session must be released before the session is closed. - * @throws SqliteEx if a mutex error occurs. - */ - void close () { - if (db == NULL) return; - int err = ::pthread_mutex_unlock (&(db->mutex)); - db = NULL; - if (err != 0) throw SqliteEx (std::string ("error unlocking the mutex: ") + ::strerror(err)); - } - /// True if the \c close method has been already called on this SqliteSession. - bool isClosed () const { - return db == NULL; - } - /** - * This class can be used in place of the SQLite handler. - * Make sure you've released any resources thus manually acquired before this SqliteSession is closed. - * Usage example: - * @code - * glim::Sqlite db (":memory:"); - * glim::SqliteSession ses (&db); - * sqlite3_exec (ses, "PRAGMA page_size = 4096;", NULL, NULL, NULL); - * @endcode - */ - operator ::sqlite3* () const {return db->handler;} -}; - -/** - * Execute the given query, throwing SqliteEx on failure.\n - * Example:\code - * glim::Sqlite sqlite (":memory:"); - * sqlite.exec ("PRAGMA page_size = 4096") .exec ("PRAGMA secure_delete = 1"); \endcode - */ -inline Sqlite& Sqlite::exec (const char* query) { - SqliteSession ses (this); // Maintains the locks. - char* errmsg = NULL; ::sqlite3_exec (handler, query, NULL, NULL, &errmsg); - if (errmsg) throw SqliteEx (std::string ("Sqlite::exec, error in query (") + query + "): " + errmsg); - return *this; -} - -/** - * Wraps the sqlite3_stmt; will prepare it, bind values, query and finalize. - */ -class SqliteQuery { - protected: - ::sqlite3_stmt* statement; - SqliteSession* session; - int bindCounter; - /// -1 if statement isn't DONE. - int mChanges; - void prepare (SqliteSession* session, char const* query, int queryLength) { - ::sqlite3* handler = *session; - if (::sqlite3_prepare_v2 (handler, query, queryLength, &statement, NULL) != SQLITE_OK) - throw SqliteEx (std::string(query, queryLength) + ": " + ::sqlite3_errmsg(handler)); - } - /** Shan't copy. */ - SqliteQuery (const SqliteQuery& other) = delete; - public: - SqliteQuery (SqliteQuery&& rvalue) { - statement = rvalue.statement; - session = rvalue.session; - bindCounter = rvalue.bindCounter; - mChanges = rvalue.mChanges; - rvalue.statement = nullptr; - } - /** - * Prepares the query. - * @throws SqliteEx if sqlite3_prepare fails; format of the error message is "$query: $errmsg". - */ - SqliteQuery (SqliteSession* session, char const* query, int queryLength) - : statement (NULL), session (session), bindCounter (0), mChanges (-1) { - prepare (session, query, queryLength); - } - /** - * Prepares the query. - * @throws SqliteEx if sqlite3_prepare fails; format of the error message is "$query: $errmsg". - */ - SqliteQuery (SqliteSession* session, std::pair<char const*, int> query) - : statement (NULL), session (session), bindCounter (0), mChanges (-1) { - prepare (session, query.first, query.second); - } - /** - * Prepares the query. - * @throws SqliteEx if sqlite3_prepare fails; format of the error message is "$query: $errmsg". - */ - SqliteQuery (SqliteSession* session, std::string query) - : statement (NULL), session (session), bindCounter (0), mChanges (-1) { - prepare (session, query.c_str(), query.length()); - } - /** - * Release resources. - * @see http://sqlite.org/capi3ref.html#sqlite3_finalize - */ - ~SqliteQuery () { - if (statement) ::sqlite3_finalize (statement); - } - - /// Call this (followed by the #step) if you need the query to be re-executed. - /// @see http://sqlite.org/capi3ref.html#sqlite3_reset - SqliteQuery& reset () { - bindCounter = 0; - mChanges = -1; - ::sqlite3_reset (statement); - return *this; - } - - /// Synonym for #step. - bool next () {return step();} - /** - * Invokes sqlite3_step. - * @return \c true if there was a row fetched successfully, \c false if there is no more rows. - * @see http://sqlite.org/capi3ref.html#sqlite3_step - */ - bool step () { - if (mChanges >= 0) {mChanges = 0; return false;} - int ret = ::sqlite3_step (statement); - if (ret == SQLITE_ROW) return true; - if (ret == SQLITE_DONE) { - mChanges = ::sqlite3_changes (*session); - return false; - } - throw SqliteEx (std::string(::sqlite3_errmsg(*session))); - } - /** - * Perform #step and throw an exception if #step has returned \c false. - * Usage example: - * \code (ses.query(S("select count(*) from test where idx = ?")) << 12345).qstep().intAt(1) \endcode - */ - SqliteQuery& qstep () { - if (!step()) - throw SqliteEx (std::string("qstep: no rows returned / affected")); - return *this; - } - /** - * Invokes a DML query and returns the number of rows affected. - * Example: \code - * int affected = (ses.query(S("update test set count = count + ? where id = ?")) << 1 << 9).ustep(); - * \endcode - * @see http://sqlite.org/capi3ref.html#sqlite3_step - */ - int ustep () { - int ret = ::sqlite3_step (statement); - if (ret == SQLITE_DONE) { - mChanges = ::sqlite3_changes (*session); - return mChanges; - } - if (ret == SQLITE_ROW) return 0; - throw SqliteEx (std::string(::sqlite3_errmsg(*session))); - } - - /** - * The number of rows changed by the query. - * Providing the query was a DML (Data Modification Language), - * returns the number of rows updated.\n - * If the query wasn't a DML, returned value is undefined.\n - * -1 is returned if the query wasn't executed, or after #reset.\n - * Example: \code - * SqliteQuery query (&ses, S("update test set count = count + ? where id = ?")); - * query.bind (1, 1); - * query.bind (2, 9); - * query.step (); - * int affected = query.changes (); - * \endcode - * @see #ustep - */ - int changes () {return mChanges;} - - /** - * The integer value of the given column. - * @param column 1-based. - * @see http://sqlite.org/capi3ref.html#sqlite3_column_text - */ - int intAt (int column) { - return ::sqlite3_column_int (statement, --column); - } - - /** - * The integer value of the given column. - * @param column 1-based. - * @see http://sqlite.org/capi3ref.html#sqlite3_column_text - */ - sqlite3_int64 int64at (int column) { - return ::sqlite3_column_int64 (statement, --column); - } - - /** - * The floating point number from the given column. - * @param column 1-based. - * @see http://sqlite.org/capi3ref.html#sqlite3_column_text - */ - double doubleAt (int column) { - return ::sqlite3_column_double (statement, --column); - } - - /** - * Return the column as UTF-8 characters, which can be used until the next #step. - * @param column 1-based. - * @see http://sqlite.org/capi3ref.html#sqlite3_column_text - */ - std::pair<char const*, int> charsAt (int column) { - return std::pair<char const*, int> ((char const*) ::sqlite3_column_text (statement, column-1), - ::sqlite3_column_bytes (statement, column-1)); - } - - /** - * Return the column as C++ string (UTF-8). - * @param column 1-based. - */ - std::string stringAt (int column) { - return std::string ((char const*) ::sqlite3_column_text (statement, column-1), - ::sqlite3_column_bytes (statement, column-1)); - } - - /** - * The type of the column. - * SQLITE_INTEGER, SQLITE_FLOAT, SQLITE_TEXT, SQLITE_BLOB or SQLITE_NULL. - * @param column 1-based. - * @see http://sqlite.org/capi3ref.html#sqlite3_column_text - */ - int typeAt (int column) { - return ::sqlite3_column_type (statement, --column); - } - - /** - * Binds a value using one of the bind methods. - */ - template<typename T> - SqliteQuery& operator << (T value) { - return bind (++bindCounter, value); - } - /** - * Binds a value using the named parameter and one of the bind methods. - * @throws SqliteEx if the name could not be found. - * @see http://sqlite.org/capi3ref.html#sqlite3_bind_parameter_index - */ - template<typename T> - SqliteQuery& bind (char const* name, T value) { - int index = ::sqlite3_bind_parameter_index (statement, name); - if (index == 0) - throw SqliteEx (std::string ("No such parameter in the query: ") + name); - return bind (index, value); - } - - /** - * Bind a string to the query. - * @param transient must be true, if lifetime of the string might be shorter than that of the query. - */ - SqliteQuery& bind (int index, const char* text, int length, bool transient = false) { - if (::sqlite3_bind_text (statement, index, text, length, - transient ? SQLITE_TRANSIENT : SQLITE_STATIC) != SQLITE_OK) - throw SqliteEx (std::string (::sqlite3_errmsg (*session))); - return *this; - } - /** - * Bind a string to the query. - * @param transient must be true, if lifetime of the string might be shorter than that of the query. - */ - SqliteQuery& bind (int index, std::pair<const char*, int> text, bool transient = false) { - if (::sqlite3_bind_text (statement, index, text.first, text.second, - transient ? SQLITE_TRANSIENT : SQLITE_STATIC) != SQLITE_OK) - throw SqliteEx (std::string (::sqlite3_errmsg (*session))); - return *this; - } - /** - * Bind a string to the query. - * @param transient must be true, if lifetime of the string might be shorter than that of the query. - */ - SqliteQuery& bind (int index, const std::string& text, bool transient = true) { - if (::sqlite3_bind_text (statement, index, text.data(), text.length(), - transient ? SQLITE_TRANSIENT : SQLITE_STATIC) != SQLITE_OK) - throw SqliteEx (std::string (::sqlite3_errmsg (*session))); - return *this; - } - /** - * Bind an integer to the query. - */ - SqliteQuery& bind (int index, int value) { - if (::sqlite3_bind_int (statement, index, value) != SQLITE_OK) - throw SqliteEx (std::string (::sqlite3_errmsg (*session))); - return *this; - } - /** - * Bind an 64-bit integer to the query. - */ - SqliteQuery& bind (int index, sqlite3_int64 value) { - if (::sqlite3_bind_int64 (statement, index, value) != SQLITE_OK) - throw SqliteEx (std::string (::sqlite3_errmsg (*session))); - return *this; - } -}; - -/** - * Version of SqliteQuery suitable for using SQLite in parallel with other processes. - * Will automatically handle the SQLITE_SCHEMA error - * and will automatically repeat attempts after SQLITE_BUSY, - * but it requires that the query string supplied - * is constant and available during the SqliteParQuery lifetime. - * Error messages, contained in exceptions, may differ from SqliteQuery by containing the query - * (for example, the #step method will throw "$query: $errmsg" instead of just "$errmsg"). - */ -class SqliteParQuery: public SqliteQuery { - protected: - char const* query; - int queryLength; - int repeat; - int wait; - public: - /** - * Prepares the query. - * @param repeat the number of times we try to repeat the query when SQLITE_BUSY is returned. - * @param wait how long, in milliseconds (1/1000 of a second) we are to wait before repeating. - * @throws SqliteEx if sqlite3_prepare fails; format of the error message is "$query: $errmsg". - */ - SqliteParQuery (SqliteSession* session, char const* query, int queryLength, int repeat = 90, int wait = 20) - : SqliteQuery (session, query, queryLength) { - this->query = query; - this->queryLength = queryLength; - this->repeat = repeat; - this->wait = wait; - } - /** - * Prepares the query. - * @param query the SQL query together with its length. - * @param repeat the number of times we try to repeat the query when SQLITE_BUSY is returned. - * @param wait how long, in milliseconds (1/1000 of a second) we are to wait before repeating. - * @throws SqliteEx if sqlite3_prepare fails; format of the error message is "$query: $errmsg". - */ - SqliteParQuery (SqliteSession* session, std::pair<char const*, int> query, int repeat = 90, int wait = 20) - : SqliteQuery (session, query) { - this->query = query.first; - this->queryLength = query.second; - this->repeat = repeat; - this->wait = wait; - } - - bool next () {return step();} - bool step () { - if (mChanges >= 0) {mChanges = 0; return false;} - repeat: - int ret = ::sqlite3_step (statement); - if (ret == SQLITE_ROW) return true; - if (ret == SQLITE_DONE) { - mChanges = ::sqlite3_changes (*session); - return false; - } - if (ret == SQLITE_SCHEMA) { - ::sqlite3_stmt* old = statement; - prepare (session, query, queryLength); - ::sqlite3_transfer_bindings(old, statement); - ::sqlite3_finalize (old); - goto repeat; - } - if (ret == SQLITE_BUSY) for (int repeat = this->repeat; ret == SQLITE_BUSY && repeat >= 0; --repeat) { - //struct timespec ts; ts.tv_sec = 0; ts.tv_nsec = wait * 1000000; // nan is 10^-9 of sec. - //while (::nanosleep (&ts, &ts) == EINTR); - ::sqlite3_sleep (wait); - ret = ::sqlite3_step (statement); - } - throw SqliteEx (std::string(query, queryLength) + ::sqlite3_errmsg(*session)); - } -}; - -template <typename T> -SqliteQuery SqliteSession::query (T t) { - return SqliteQuery (this, t); -} - -}; // namespace glim - -#endif // GLIM_SQLITE_HPP_ |