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/* Copyright (c) 2001-2019, The HSQL Development Group
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 * 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 the HSQL Development Group 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 HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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package org.hsqldb.jdbc;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Blob;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;

import org.hsqldb.error.ErrorCode;
import org.hsqldb.lib.KMPSearchAlgorithm;
import org.hsqldb.lib.java.JavaSystem;

// campbell-burnet@users 2004-04-xx - patch 1.7.2 - position and truncate methods
//                             implemented; minor changes for moderate thread
//                             safety and optimal performance
// campbell-burnet@users 2004-04-xx - doc 1.7.2 - javadocs updated; methods put in
//                             correct (historical, interface declared) order
// campbell-burnet@users 2005-12-07 - patch 1.8.0.x - initial JDBC 4.0 support work
// campbell-burnet@users 2006-05-22 - doc 1.9.0     - full synch up to Mustang Build 84
//                           - patch 1.9.0   - setBinaryStream improvement
// patch 1.9.0
//  - fixed invalid reference to new BinaryStream(...) in getBinaryStream
//
// patch 1.9.0 - full synch up to Mustang b90
//             - better bounds checking
//             - added support for clients to decide whether getBinaryStream
//               uses copy of internal byte buffer

/**
 * The representation (mapping) in
 * the Java™ programming language of an SQL
 * BLOB value.  An SQL BLOB is a built-in type
 * that stores a Binary Large Object as a column value in a row of
 * a database table. By default drivers implement Blob using
 * an SQL locator(BLOB), which means that a
 * Blob object contains a logical pointer to the
 * SQL BLOB data rather than the data itself.
 * A Blob object is valid for the duration of the
 * transaction in which is was created.
 *
 * 

Methods in the interfaces {@link java.sql.ResultSet}, * {@link java.sql.CallableStatement}, and {@link java.sql.PreparedStatement}, such as * getBlob and setBlob allow a programmer to * access an SQL BLOB value. * The Blob interface provides methods for getting the * length of an SQL BLOB (Binary Large Object) value, * for materializing a BLOB value on the client, and for * determining the position of a pattern of bytes within a * BLOB value. In addition, this interface has methods for updating * a BLOB value. *

* All methods on the Blob interface must be fully implemented if the * JDBC driver supports the data type. * * *

*

HSQLDB-Specific Information:

* * Previous to 2.0, the HSQLDB driver did not implement Blob using an SQL * locator(BLOB). That is, an HSQLDB Blob object did not contain a logical * pointer to SQL BLOB data; rather it directly contained a representation of * the data (a byte array). As a result, an HSQLDB Blob object was itself * valid beyond the duration of the transaction in which is was created, * although it did not necessarily represent a corresponding value * on the database. Also, the interface methods for updating a BLOB value * were unsupported, with the exception of the truncate method, * in that it could be used to truncate the local value.

* * Starting with 2.0, the HSQLDB driver fully supports both local and remote * SQL BLOB data implementations, meaning that an HSQLDB Blob object may * contain a logical pointer to remote SQL BLOB data (see {@link JDBCBlobClient * JDBCBlobClient}) or it may directly contain a local representation of the * data (as implemented in this class). In particular, when the product is built * under JDK 1.6+ and the Blob instance is constructed as a result of calling * JDBCConnection.createBlob(), then the resulting Blob instance is initially * disconnected (is not bound to the transaction scope of the vending Connection * object), the data is contained directly and all interface methods for * updating the BLOB value are supported for local use until the first * invocation of free(); otherwise, an HSQLDB Blob's implementation is * determined at runtime by the driver, it is typically not valid beyond the * duration of the transaction in which is was created, and there no * standard way to query whether it represents a local or remote * value.

* *

* * * @author james house ([email protected]) * @author Campbell Burnet (campbell-burnet@users dot sourceforge.net) * @version 2.4.0 * @since JDK 1.2, HSQLDB 1.7.2 */ public class JDBCBlob implements Blob { /** * Returns the number of bytes in the BLOB value * designated by this Blob object. * @return length of the BLOB in bytes * @exception SQLException if there is an error accessing the * length of the BLOB * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @since JDK 1.2, HSQLDB 1.7.2 */ public long length() throws SQLException { return getData().length; } /** * Retrieves all or part of the BLOB * value that this Blob object represents, as an array of * bytes. This byte array contains up to length * consecutive bytes starting at position pos. * * *
*

HSQLDB-Specific Information:

* * The official specification above is ambiguous in that it does not * precisely indicate the policy to be observed when * {@code pos > this.length() - length}. One policy would be to retrieve the * octets from pos to this.length(). Another would be to throw an * exception. HSQLDB observes the second policy. *

* * * @param pos the ordinal position of the first byte in the * BLOB value to be extracted; the first byte is at * position 1 * @param length the number of consecutive bytes to be copied; JDBC 4.1[the value * for length must be 0 or greater] * @return a byte array containing up to length * consecutive bytes from the BLOB value designated * by this Blob object, starting with the * byte at position pos * @exception SQLException if there is an error accessing the * BLOB value; if pos is less than 1 or length is * less than 0 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @see #setBytes * @since JDK 1.2, HSQLDB 1.7.2 */ public byte[] getBytes(long pos, final int length) throws SQLException { final byte[] data = getData(); final int dlen = data.length; if (pos < MIN_POS || pos - MIN_POS > dlen) { throw JDBCUtil.outOfRangeArgument("pos: " + pos); } final int index = (int) pos - 1; if (length < 0 || length > dlen - index) { throw JDBCUtil.outOfRangeArgument("length: " + length); } final byte[] result = new byte[length]; System.arraycopy(data, index, result, 0, length); return result; } /** * Retrieves the BLOB value designated by this * Blob instance as a stream. * * @return a stream containing the BLOB data * @exception SQLException if there is an error accessing the * BLOB value * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @see #setBinaryStream * @since JDK 1.2, HSQLDB 1.7.2 */ public InputStream getBinaryStream() throws SQLException { return new ByteArrayInputStream(getData()); } /** * Retrieves the byte position at which the specified byte array * pattern begins within the BLOB * value that this Blob object represents. The * search for pattern begins at position * start. * * @param pattern the byte array for which to search * @param start the position at which to begin searching; the * first position is 1 * @return the position at which the pattern appears, else -1 * @exception SQLException if there is an error accessing the * BLOB or if start is less than 1 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @since JDK 1.2, HSQLDB 1.7.2 */ public long position(final byte[] pattern, final long start) throws SQLException { final byte[] data = getData(); final int dlen = data.length; if (start < MIN_POS) { throw JDBCUtil.outOfRangeArgument("start: " + start); } else if (start > dlen || pattern == null) { return -1L; } // by now, we know start <= Integer.MAX_VALUE; final int startIndex = (int) start - 1; final int plen = pattern.length; if (plen == 0 || startIndex > dlen - plen) { return -1L; } final int result = KMPSearchAlgorithm.search(data, pattern, KMPSearchAlgorithm.computeTable(pattern), startIndex); return (result == -1) ? -1 : result + 1; } /** * Retrieves the byte position in the BLOB value * designated by this Blob object at which * pattern begins. The search begins at position * start. * * @param pattern the Blob object designating * the BLOB value for which to search * @param start the position in the BLOB value * at which to begin searching; the first position is 1 * @return the position at which the pattern begins, else -1 * @exception SQLException if there is an error accessing the * BLOB value or if start is less than 1 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @since JDK 1.2, HSQLDB 1.7.2 */ public long position(final Blob pattern, long start) throws SQLException { final byte[] data = getData(); final int dlen = data.length; if (start < MIN_POS) { throw JDBCUtil.outOfRangeArgument("start: " + start); } else if (start > dlen || pattern == null) { return -1L; } // by now, we know start <= Integer.MAX_VALUE; final int startIndex = (int) (start - MIN_POS); final long plen = pattern.length(); if (plen == 0 || startIndex > ((long) dlen) - plen) { return -1L; } // by now, we know plen <= Integer.MAX_VALUE final int iplen = (int) plen; byte[] bytePattern; if (pattern instanceof JDBCBlob) { bytePattern = ((JDBCBlob) pattern).data(); } else { bytePattern = pattern.getBytes(1L, iplen); } final int result = KMPSearchAlgorithm.search(data, bytePattern, KMPSearchAlgorithm.computeTable(bytePattern), startIndex); return (result == -1) ? -1 : result + 1; } // -------------------------- JDBC 3.0 ----------------------------------- /** * Writes the given array of bytes to the BLOB value that * this Blob object represents, starting at position * pos, and returns the number of bytes written. * The array of bytes will overwrite the existing bytes * in the Blob object starting at the position * pos. If the end of the Blob value is reached * while writing the array of bytes, then the length of the Blob * value will be increased to accommodate the extra bytes. *

* Note: If the value specified for pos * is greater then the length+1 of the BLOB value then the * behavior is undefined. Some JDBC drivers may throw a * SQLException while other drivers may support this * operation. * * *

*

HSQLDB-Specific Information:

* * Starting with HSQLDB 2.0 this feature is supported.

* * When built under JDK 1.6+ and the Blob instance is constructed as a * result of calling JDBCConnection.createBlob(), this operation affects * only the client-side value; it has no effect upon a value stored in a * database because JDBCConnection.createBlob() constructs disconnected, * initially empty Blob instances. To propagate the Blob value to a database * in this case, it is required to supply the Blob instance to an updating * or inserting setXXX method of a Prepared or Callable Statement, or to * supply the Blob instance to an updateXXX method of an updatable * ResultSet.

* * Implementation Notes:

* * Starting with HSQLDB 2.1, JDBCBlob no longer utilizes volatile fields * and is effectively thread safe, but still uses local variable * snapshot isolation.

* * As such, the synchronization policy still does not strictly enforce * serialized read/write access to the underlying data

* * So, if an application may perform concurrent JDBCBlob modifications and * the integrity of the application depends on total order Blob modification * semantics, then such operations should be synchronized on an appropriate * monitor.

* *

* * * @param pos the position in the BLOB object at which * to start writing; the first position is 1 * @param bytes the array of bytes to be written to the BLOB * value that this Blob object represents * @return the number of bytes written * @exception SQLException if there is an error accessing the * BLOB value or if pos is less than 1 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @see #getBytes * @since JDK 1.4, HSQLDB 1.7.2 */ public int setBytes(long pos, byte[] bytes) throws SQLException { return setBytes(pos, bytes, 0, bytes == null ? 0 : bytes.length); } /** * Writes all or part of the given byte array to the * BLOB value that this Blob object represents * and returns the number of bytes written. * Writing starts at position pos in the BLOB * value; len bytes from the given byte array are written. * The array of bytes will overwrite the existing bytes * in the Blob object starting at the position * pos. If the end of the Blob value is reached * while writing the array of bytes, then the length of the Blob * value will be increased to accommodate the extra bytes. *

* Note: If the value specified for pos * is greater then the length+1 of the BLOB value then the * behavior is undefined. Some JDBC drivers may throw a * SQLException while other drivers may support this * operation. * * *

*

HSQLDB-Specific Information:

* * Starting with HSQLDB 2.0 this feature is supported.

* * When built under JDK 1.6+ and the Blob instance is constructed as a * result of calling JDBCConnection.createBlob(), this operation affects * only the client-side value; it has no effect upon a value stored in a * database because JDBCConnection.createBlob() constructs disconnected, * initially empty Blob instances. To propagate the Blob value to a database * in this case, it is required to supply the Blob instance to an updating * or inserting setXXX method of a Prepared or Callable Statement, or to * supply the Blob instance to an updateXXX method of an updatable * ResultSet.

* * Implementation Notes:

* * If the value specified for pos * is greater than the length of the BLOB value, then * the BLOB value is extended in length to accept the * written octets and the undefined region up to pos is * filled with (byte)0.

* * Starting with HSQLDB 2.1, JDBCBlob no longer utilizes volatile fields * and is effectively thread safe, but still uses local variable * snapshot isolation.

* * As such, the synchronization policy still does not strictly enforce * serialized read/write access to the underlying data

* * So, if an application may perform concurrent JDBCBlob modifications and * the integrity of the application depends on total order Blob modification * semantics, then such operations should be synchronized on an appropriate * monitor.

* *

* * * @param pos the position in the BLOB object at which * to start writing; the first position is 1 * @param bytes the array of bytes to be written to this BLOB * object * @param offset the offset into the array bytes at which * to start reading the bytes to be set * @param len the number of bytes to be written to the BLOB * value from the array of bytes bytes * @return the number of bytes written * @exception SQLException if there is an error accessing the * BLOB value or if pos is less than 1 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @see #getBytes * @since JDK 1.4, HSQLDB 1.7.2 */ public int setBytes(long pos, byte[] bytes, int offset, int len) throws SQLException { checkReadonly(); if (bytes == null) { throw JDBCUtil.nullArgument("bytes"); } if (offset < 0 || offset > bytes.length) { throw JDBCUtil.outOfRangeArgument("offset: " + offset); } if (len > bytes.length - offset) { throw JDBCUtil.outOfRangeArgument("len: " + len); } if (pos < MIN_POS || (pos - MIN_POS) > (Integer.MAX_VALUE - len)) { throw JDBCUtil.outOfRangeArgument("pos: " + pos); } final int index = (int) (pos - MIN_POS); byte[] data = getData(); final int dlen = data.length; if (index > dlen - len) { byte[] temp = new byte[index + len]; System.arraycopy(data, 0, temp, 0, dlen); data = temp; temp = null; } System.arraycopy(bytes, offset, data, index, len); setData(data); return len; } /** * Retrieves a stream that can be used to write to the BLOB * value that this Blob object represents. The stream begins * at position pos. * The bytes written to the stream will overwrite the existing bytes * in the Blob object starting at the position * pos. If the end of the Blob value is reached * while writing to the stream, then the length of the Blob * value will be increased to accommodate the extra bytes. *

* Note: If the value specified for pos * is greater then the length+1 of the BLOB value then the * behavior is undefined. Some JDBC drivers may throw a * SQLException while other drivers may support this * operation. * * *

*

HSQLDB-Specific Information:

* * Starting with HSQLDB 2.0 this feature is supported.

* * When built under JDK 1.6+ and the Blob instance is constructed as a * result of calling JDBCConnection.createBlob(), this operation affects * only the client-side value; it has no effect upon a value stored in a * database because JDBCConnection.createBlob() constructs disconnected, * initially empty Blob instances. To propagate the Blob value to a database * in this case, it is required to supply the Blob instance to an updating * or inserting setXXX method of a Prepared or Callable Statement, or to * supply the Blob instance to an updateXXX method of an updatable * ResultSet.

* * Implementation Notes:

* * The data written to the stream does not appear in this * Blob until the stream is closed

* * When the stream is closed, if the value specified for pos * is greater than the length of the BLOB value, then * the BLOB value is extended in length to accept the * written octets and the undefined region up to pos is * filled with (byte)0.

* * Starting with HSQLDB 2.1, JDBCBlob no longer utilizes volatile fields * and is effectively thread safe, but still uses local variable * snapshot isolation.

* * As such, the synchronization policy still does not strictly enforce * serialized read/write access to the underlying data

* * So, if an application may perform concurrent JDBCBlob modifications and * the integrity of the application depends on total order Blob modification * semantics, then such operations should be synchronized on an appropriate * monitor.

* *

* * * @param pos the position in the BLOB value at which * to start writing; the first position is 1 * @return a java.io.OutputStream object to which data can * be written * @exception SQLException if there is an error accessing the * BLOB value or if pos is less than 1 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @see #getBinaryStream * @since JDK 1.4, HSQLDB 1.7.2 */ public OutputStream setBinaryStream(final long pos) throws SQLException { checkReadonly(); if (pos < MIN_POS || pos > MAX_POS) { throw JDBCUtil.outOfRangeArgument("pos: " + pos); } checkClosed(); return new java.io.ByteArrayOutputStream() { private boolean closed; public synchronized void close() throws java.io.IOException { if (closed) { return; } closed = true; byte[] bytes = super.buf; int length = super.count; super.buf = NO_BYTES; super.count = 0; try { JDBCBlob.this.setBytes(pos, bytes, 0, length); } catch (SQLException se) { throw JavaSystem.toIOException(se); } finally { super.close(); } } }; } /** * Truncates the BLOB value that this Blob * object represents to be len bytes in length. *

* Note: If the value specified for pos * is greater then the length+1 of the BLOB value then the * behavior is undefined. Some JDBC drivers may throw a * SQLException while other drivers may support this * operation. * * *

*

HSQLDB-Specific Information:

* * Starting with HSQLDB 2.0 this feature is fully supported.

* * When built under JDK 1.6+ and the Blob instance is constructed as a * result of calling JDBCConnection.createBlob(), this operation affects * only the client-side value; it has no effect upon a value stored in a * database because JDBCConnection.createBlob() constructs disconnected, * initially empty Blob instances. To propagate the truncated Blob value to * a database in this case, it is required to supply the Blob instance to * an updating or inserting setXXX method of a Prepared or Callable * Statement, or to supply the Blob instance to an updateXXX method of an * updateable ResultSet.

* *

* * * @param len the length, in bytes, to which the BLOB value * that this Blob object represents should be truncated * @exception SQLException if there is an error accessing the * BLOB value or if len is less than 0 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @since JDK 1.4, HSQLDB 1.7.2 */ public void truncate(final long len) throws SQLException { checkReadonly(); final byte[] data = getData(); if (len < 0 || len > data.length) { throw JDBCUtil.outOfRangeArgument("len: " + len); } else if (len == data.length) { return; } byte[] newData = new byte[(int) len]; System.arraycopy(data, 0, newData, 0, (int) len); setData(newData); } //------------------------- JDBC 4.0 ----------------------------------- /** * This method frees the Blob object and releases the resources that * it holds. The object is invalid once the free * method is called. *

* After free has been called, any attempt to invoke a * method other than free will result in a SQLException * being thrown. If free is called multiple times, the subsequent * calls to free are treated as a no-op. *

* * @throws SQLException if an error occurs releasing * the Blob's resources * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @since JDK 1.6, HSQLDB 2.0 */ public synchronized void free() throws SQLException { m_closed = true; m_data = null; } /** * Returns an InputStream object that contains a partial Blob value, * starting with the byte specified by pos, which is length bytes in length. * * @param pos the offset to the first byte of the partial value to be retrieved. * The first byte in the Blob is at position 1 * @param length the length in bytes of the partial value to be retrieved * @return InputStream through which the partial Blob value can be read. * @throws SQLException if pos is less than 1 or if pos is greater than the number of bytes * in the Blob or if pos + length is greater than the number of bytes * in the Blob * * @exception SQLFeatureNotSupportedException if the JDBC driver does not support * this method * @since JDK 1.6, HSQLDB 2.0 */ public InputStream getBinaryStream(long pos, long length) throws SQLException { final byte[] data = getData(); final int dlen = data.length; if (pos < MIN_POS || pos > dlen) { throw JDBCUtil.outOfRangeArgument("pos: " + pos); } int index = (int) (pos - MIN_POS); if (length < 0 || length > dlen - index) { throw JDBCUtil.outOfRangeArgument("length: " + length); } if (index == 0 && length == dlen) { return new ByteArrayInputStream(data); } final int ilength = (int) length; final byte[] result = new byte[ilength]; System.arraycopy(data, index, result, 0, ilength); return new ByteArrayInputStream(result); } // ---------------------- internal implementation -------------------------- private static final long MIN_POS = 1L; private static final long MAX_POS = MIN_POS + (long) Integer.MAX_VALUE; private static final byte[] NO_BYTES = new byte[0]; private boolean m_closed; private byte[] m_data; private final boolean m_createdByConnection; /** * Constructs a new JDBCBlob instance wrapping the given octet sequence.

* * This constructor is used internally to retrieve result set values as * Blob objects, yet it must be public to allow access from other packages. * As such (in the interest of efficiency) this object maintains a reference * to the given octet sequence rather than making a copy; special care * should be taken by external clients never to use this constructor with a * byte array object that may later be modified externally. * * @param data the octet sequence representing the Blob value * @throws SQLException if the argument is null */ public JDBCBlob(final byte[] data) throws SQLException { if (data == null) { throw JDBCUtil.nullArgument("data"); } m_data = data; m_createdByConnection = false; } protected JDBCBlob() { m_data = new byte[0]; m_createdByConnection = true; } protected void checkReadonly() throws SQLException { if (!m_createdByConnection) { throw JDBCUtil.sqlException(ErrorCode.X_25006, "Blob is read-only"); } } protected synchronized void checkClosed() throws SQLException { if (m_closed) { throw JDBCUtil.sqlException(ErrorCode.X_07501); } } protected byte[] data() throws SQLException { return getData(); } //@SuppressWarnings("ReturnOfCollectionOrArrayField") private synchronized byte[] getData() throws SQLException { checkClosed(); return m_data; } //@SuppressWarnings("AssignmentToCollectionOrArrayFieldFromParameter") private synchronized void setData(byte[] data) throws SQLException { checkClosed(); m_data = data; } }





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