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package org.sqlite;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;
import java.util.UUID;
import java.util.concurrent.Executor;
import org.sqlite.SQLiteConfig.TransactionMode;
import org.sqlite.core.CoreDatabaseMetaData;
import org.sqlite.core.DB;
import org.sqlite.core.NativeDB;
import org.sqlite.jdbc4.JDBC4DatabaseMetaData;

/** */
public abstract class SQLiteConnection implements Connection {
    private static final String RESOURCE_NAME_PREFIX = ":resource:";
    private final DB db;
    private CoreDatabaseMetaData meta = null;
    private final SQLiteConnectionConfig connectionConfig;

    private TransactionMode currentTransactionMode;
    private boolean firstStatementExecuted = false;

    /**
     * Connection constructor for reusing an existing DB handle
     *
     * @param db
     */
    public SQLiteConnection(DB db) {
        this.db = db;
        connectionConfig = db.getConfig().newConnectionConfig();
    }

    /**
     * Constructor to create a connection to a database at the given location.
     *
     * @param url The location of the database.
     * @param fileName The database.
     * @throws SQLException
     */
    public SQLiteConnection(String url, String fileName) throws SQLException {
        this(url, fileName, new Properties());
    }

    /**
     * Constructor to create a pre-configured connection to a database at the given location.
     *
     * @param url The location of the database file.
     * @param fileName The database.
     * @param prop The configurations to apply.
     * @throws SQLException
     */
    public SQLiteConnection(String url, String fileName, Properties prop) throws SQLException {
        DB newDB = null;
        try {
            this.db = newDB = open(url, fileName, prop);
            SQLiteConfig config = this.db.getConfig();
            this.connectionConfig = this.db.getConfig().newConnectionConfig();
            config.apply(this);
            this.currentTransactionMode = this.getDatabase().getConfig().getTransactionMode();
            // connection starts in "clean" state (even though some PRAGMA statements were executed)
            this.firstStatementExecuted = false;
        } catch (Throwable t) {
            try {
                if (newDB != null) {
                    newDB.close();
                }
            } catch (Exception e) {
                t.addSuppressed(e);
            }
            throw t;
        }
    }

    public TransactionMode getCurrentTransactionMode() {
        return this.currentTransactionMode;
    }

    public void setCurrentTransactionMode(final TransactionMode currentTransactionMode) {
        this.currentTransactionMode = currentTransactionMode;
    }

    public void setFirstStatementExecuted(final boolean firstStatementExecuted) {
        this.firstStatementExecuted = firstStatementExecuted;
    }

    public boolean isFirstStatementExecuted() {
        return firstStatementExecuted;
    }

    public SQLiteConnectionConfig getConnectionConfig() {
        return connectionConfig;
    }

    public CoreDatabaseMetaData getSQLiteDatabaseMetaData() throws SQLException {
        checkOpen();

        if (meta == null) {
            meta = new JDBC4DatabaseMetaData(this);
        }

        return meta;
    }

    @Override
    public DatabaseMetaData getMetaData() throws SQLException {
        return (DatabaseMetaData) getSQLiteDatabaseMetaData();
    }

    public String getUrl() {
        return db.getUrl();
    }

    public void setSchema(String schema) throws SQLException {
        // TODO
    }

    public String getSchema() throws SQLException {
        // TODO
        return null;
    }

    public void abort(Executor executor) throws SQLException {
        // TODO
    }

    public void setNetworkTimeout(Executor executor, int milliseconds) throws SQLException {
        // TODO
    }

    public int getNetworkTimeout() throws SQLException {
        // TODO
        return 0;
    }

    /**
     * Checks whether the type, concurrency, and holdability settings for a {@link ResultSet} are
     * supported by the SQLite interface. Supported settings are:
     *
     * 
    *
  • type: {@link ResultSet#TYPE_FORWARD_ONLY} *
  • concurrency: {@link ResultSet#CONCUR_READ_ONLY}) *
  • holdability: {@link ResultSet#CLOSE_CURSORS_AT_COMMIT} *
* * @param rst the type setting. * @param rsc the concurrency setting. * @param rsh the holdability setting. * @throws SQLException */ protected void checkCursor(int rst, int rsc, int rsh) throws SQLException { if (rst != ResultSet.TYPE_FORWARD_ONLY) throw new SQLException("SQLite only supports TYPE_FORWARD_ONLY cursors"); if (rsc != ResultSet.CONCUR_READ_ONLY) throw new SQLException("SQLite only supports CONCUR_READ_ONLY cursors"); if (rsh != ResultSet.CLOSE_CURSORS_AT_COMMIT) throw new SQLException("SQLite only supports closing cursors at commit"); } /** * Sets the mode that will be used to start transactions on this connection. * * @param mode One of {@link SQLiteConfig.TransactionMode} * @see https://www.sqlite.org/lang_transaction.html */ protected void setTransactionMode(SQLiteConfig.TransactionMode mode) { connectionConfig.setTransactionMode(mode); } /** @see java.sql.Connection#getTransactionIsolation() */ @Override public int getTransactionIsolation() { return connectionConfig.getTransactionIsolation(); } /** @see java.sql.Connection#setTransactionIsolation(int) */ public void setTransactionIsolation(int level) throws SQLException { checkOpen(); switch (level) { case java.sql.Connection.TRANSACTION_READ_COMMITTED: case java.sql.Connection.TRANSACTION_REPEATABLE_READ: // Fall-through: Spec allows upgrading isolation to a higher level case java.sql.Connection.TRANSACTION_SERIALIZABLE: getDatabase().exec("PRAGMA read_uncommitted = false;", getAutoCommit()); break; case java.sql.Connection.TRANSACTION_READ_UNCOMMITTED: getDatabase().exec("PRAGMA read_uncommitted = true;", getAutoCommit()); break; default: throw new SQLException( "Unsupported transaction isolation level: " + level + ". " + "Must be one of TRANSACTION_READ_UNCOMMITTED, TRANSACTION_READ_COMMITTED, " + "TRANSACTION_REPEATABLE_READ, or TRANSACTION_SERIALIZABLE in java.sql.Connection"); } connectionConfig.setTransactionIsolation(level); } /** * Opens a connection to the database using an SQLite library. * @throws SQLException * * @see https://www.sqlite.org/c3ref/c_open_autoproxy.html */ private static DB open(String url, String origFileName, Properties props) throws SQLException { // Create a copy of the given properties Properties newProps = new Properties(); newProps.putAll(props); // Extract pragma as properties String fileName = extractPragmasFromFilename(url, origFileName, newProps); SQLiteConfig config = new SQLiteConfig(newProps); // check the path to the file exists if (!fileName.isEmpty() && !":memory:".equals(fileName) && !fileName.startsWith("file:") && !fileName.contains("mode=memory")) { if (fileName.startsWith(RESOURCE_NAME_PREFIX)) { String resourceName = fileName.substring(RESOURCE_NAME_PREFIX.length()); // search the class path ClassLoader contextCL = Thread.currentThread().getContextClassLoader(); URL resourceAddr = contextCL.getResource(resourceName); if (resourceAddr == null) { try { resourceAddr = new URL(resourceName); } catch (MalformedURLException e) { throw new SQLException( String.format("resource %s not found: %s", resourceName, e)); } } try { fileName = extractResource(resourceAddr).getAbsolutePath(); } catch (IOException e) { throw new SQLException(String.format("failed to load %s: %s", resourceName, e)); } } else { File file = new File(fileName).getAbsoluteFile(); File parent = file.getParentFile(); if (parent != null && !parent.exists()) { for (File up = parent; up != null && !up.exists(); ) { parent = up; up = up.getParentFile(); } throw new SQLException( "path to '" + fileName + "': '" + parent + "' does not exist"); } // check write access if file does not exist try { // The extra check to exists() is necessary as createNewFile() // does not follow the JavaDoc when used on read-only shares. if (!file.exists() && file.createNewFile()) file.delete(); } catch (Exception e) { throw new SQLException("opening db: '" + fileName + "': " + e.getMessage()); } fileName = file.getAbsolutePath(); } } // load the native DB DB db = null; try { NativeDB.load(); db = new NativeDB(url, fileName, config); } catch (Exception e) { SQLException err = new SQLException("Error opening connection"); err.initCause(e); throw err; } db.open(fileName, config.getOpenModeFlags()); return db; } /** * Returns a file name from the given resource address. * * @param resourceAddr The resource address. * @return The extracted file name. * @throws IOException */ private static File extractResource(URL resourceAddr) throws IOException { if (resourceAddr.getProtocol().equals("file")) { try { return new File(resourceAddr.toURI()); } catch (URISyntaxException e) { throw new IOException(e.getMessage()); } } String tempFolder = new File(System.getProperty("java.io.tmpdir")).getAbsolutePath(); String dbFileName = String.format("sqlite-jdbc-tmp-%s.db", UUID.randomUUID()); File dbFile = new File(tempFolder, dbFileName); if (dbFile.exists()) { long resourceLastModified = resourceAddr.openConnection().getLastModified(); long tmpFileLastModified = dbFile.lastModified(); if (resourceLastModified < tmpFileLastModified) { return dbFile; } else { // remove the old DB file boolean deletionSucceeded = dbFile.delete(); if (!deletionSucceeded) { throw new IOException( "failed to remove existing DB file: " + dbFile.getAbsolutePath()); } } // String md5sum1 = SQLiteJDBCLoader.md5sum(resourceAddr.openStream()); // String md5sum2 = SQLiteJDBCLoader.md5sum(new FileInputStream(dbFile)); // // if (md5sum1.equals(md5sum2)) // return dbFile; // no need to extract the DB file // else // { // } } URLConnection conn = resourceAddr.openConnection(); // Disable caches to avoid keeping unnecessary file references after the single-use copy conn.setUseCaches(false); try (InputStream reader = conn.getInputStream()) { Files.copy(reader, dbFile.toPath(), StandardCopyOption.REPLACE_EXISTING); return dbFile; } } public DB getDatabase() { return db; } /** @see java.sql.Connection#getAutoCommit() */ @Override public boolean getAutoCommit() throws SQLException { checkOpen(); return connectionConfig.isAutoCommit(); } /** @see java.sql.Connection#setAutoCommit(boolean) */ @Override public void setAutoCommit(boolean ac) throws SQLException { checkOpen(); if (connectionConfig.isAutoCommit() == ac) return; connectionConfig.setAutoCommit(ac); // db.exec(connectionConfig.isAutoCommit() ? "commit;" : this.transactionPrefix(), ac); if (this.getConnectionConfig().isAutoCommit()) { db.exec("commit;", ac); this.currentTransactionMode = null; } else { db.exec(this.transactionPrefix(), ac); this.currentTransactionMode = this.getConnectionConfig().getTransactionMode(); } } /** * @return The busy timeout value for the connection. * @see https://www.sqlite.org/c3ref/busy_timeout.html */ public int getBusyTimeout() { return db.getConfig().getBusyTimeout(); } /** * Sets the timeout value for the connection. A timeout value less than or equal to zero turns * off all busy handlers. * * @see https://www.sqlite.org/c3ref/busy_timeout.html * @param timeoutMillis The timeout value in milliseconds. * @throws SQLException */ public void setBusyTimeout(int timeoutMillis) throws SQLException { db.getConfig().setBusyTimeout(timeoutMillis); db.busy_timeout(timeoutMillis); } public void setLimit(SQLiteLimits limit, int value) throws SQLException { // Calling sqlite3_limit with a negative number is a no-op: // https://www.sqlite.org/c3ref/limit.html if (value >= 0) { db.limit(limit.getId(), value); } } public void getLimit(SQLiteLimits limit) throws SQLException { db.limit(limit.getId(), -1); } @Override public boolean isClosed() throws SQLException { return db.isClosed(); } /** @see java.sql.Connection#close() */ @Override public void close() throws SQLException { if (isClosed()) return; if (meta != null) meta.close(); db.close(); } /** * Whether an SQLite library interface to the database has been established. * * @throws SQLException */ protected void checkOpen() throws SQLException { if (isClosed()) throw new SQLException("database connection closed"); } /** * @return Compile-time library version numbers. * @throws SQLException * @see https://www.sqlite.org/c3ref/c_source_id.html */ public String libversion() throws SQLException { checkOpen(); return db.libversion(); } /** @see java.sql.Connection#commit() */ @Override public void commit() throws SQLException { checkOpen(); if (connectionConfig.isAutoCommit()) throw new SQLException("database in auto-commit mode"); db.exec("commit;", getAutoCommit()); db.exec(this.transactionPrefix(), getAutoCommit()); this.firstStatementExecuted = false; this.setCurrentTransactionMode(this.getConnectionConfig().getTransactionMode()); } /** @see java.sql.Connection#rollback() */ @Override public void rollback() throws SQLException { checkOpen(); if (connectionConfig.isAutoCommit()) throw new SQLException("database in auto-commit mode"); db.exec("rollback;", getAutoCommit()); db.exec(this.transactionPrefix(), getAutoCommit()); this.firstStatementExecuted = false; this.setCurrentTransactionMode(this.getConnectionConfig().getTransactionMode()); } /** * Add a listener for DB update events, see https://www.sqlite.org/c3ref/update_hook.html * * @param listener The listener to receive update events */ public void addUpdateListener(SQLiteUpdateListener listener) { db.addUpdateListener(listener); } /** * Remove a listener registered for DB update events. * * @param listener The listener to no longer receive update events */ public void removeUpdateListener(SQLiteUpdateListener listener) { db.removeUpdateListener(listener); } /** * Add a listener for DB commit/rollback events, see * https://www.sqlite.org/c3ref/commit_hook.html * * @param listener The listener to receive commit events */ public void addCommitListener(SQLiteCommitListener listener) { db.addCommitListener(listener); } /** * Remove a listener registered for DB commit/rollback events. * * @param listener The listener to no longer receive commit/rollback events. */ public void removeCommitListener(SQLiteCommitListener listener) { db.removeCommitListener(listener); } /** * Extracts PRAGMA values from the filename and sets them into the Properties object which will * be used to build the SQLConfig. The sanitized filename is returned. * * @param filename * @param prop * @return a PRAGMA-sanitized filename * @throws SQLException */ protected static String extractPragmasFromFilename(String url, String filename, Properties prop) throws SQLException { int parameterDelimiter = filename.indexOf('?'); if (parameterDelimiter == -1) { // nothing to extract return filename; } StringBuilder sb = new StringBuilder(); sb.append(filename.substring(0, parameterDelimiter)); int nonPragmaCount = 0; String[] parameters = filename.substring(parameterDelimiter + 1).split("&"); for (int i = 0; i < parameters.length; i++) { // process parameters in reverse-order, last specified pragma value wins String parameter = parameters[parameters.length - 1 - i].trim(); if (parameter.isEmpty()) { // duplicated &&& sequence, drop continue; } String[] kvp = parameter.split("="); String key = kvp[0].trim().toLowerCase(); if (SQLiteConfig.pragmaSet.contains(key)) { if (kvp.length == 1) { throw new SQLException( String.format( "Please specify a value for PRAGMA %s in URL %s", key, url)); } String value = kvp[1].trim(); if (!value.isEmpty()) { if (prop.containsKey(key)) { // // IGNORE // // this allows DriverManager.getConnection(String, Properties) // to override URL parameters programmatically. // // It also ignores duplicate pragma keys in the URL. The reversed // processing order ensures the last-supplied pragma value is used. } else { prop.setProperty(key, value); } } } else { // not a Pragma, retain as part of filename sb.append(nonPragmaCount == 0 ? '?' : '&'); sb.append(parameter); nonPragmaCount++; } } final String newFilename = sb.toString(); return newFilename; } protected String transactionPrefix() { return this.connectionConfig.transactionPrefix(); } /** * Returns a byte array representing the schema content. This method is intended for in-memory * schemas. Serialized databases are limited to 2gb. * * @param schema The schema to serialize * @return A byte[] holding the database content */ public byte[] serialize(String schema) throws SQLException { return db.serialize(schema); } /** * Deserialize the schema using the given byte array. This method is intended for in-memory * database. The call will replace the content of an existing schema. To make sure there is an * existing schema, first execute ATTACH ':memory:' AS schema_name * * @param schema The schema to serialize * @param buff The buffer to deserialize */ public void deserialize(String schema, byte[] buff) throws SQLException { db.deserialize(schema, buff); } }




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