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/*
* Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.value;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import org.h2.engine.Constants;
import org.h2.engine.SysProperties;
import org.h2.message.DbException;
import org.h2.mvstore.DataUtils;
import org.h2.store.DataHandler;
import org.h2.store.FileStore;
import org.h2.store.FileStoreInputStream;
import org.h2.store.FileStoreOutputStream;
import org.h2.store.fs.FileUtils;
import org.h2.util.IOUtils;
import org.h2.util.MathUtils;
import org.h2.util.SmallLRUCache;
import org.h2.util.StringUtils;
import org.h2.util.Utils;
/**
* Implementation of the BLOB and CLOB data types. Small objects are kept in
* memory and stored in the record.
*
* Large objects are stored in their own files. When large objects are set in a
* prepared statement, they are first stored as 'temporary' files. Later, when
* they are used in a record, and when the record is stored, the lob files are
* linked: the file is renamed using the file format (tableId).(objectId). There
* is one exception: large variables are stored in the file (-1).(objectId).
*
* When lobs are deleted, they are first renamed to a temp file, and if the
* delete operation is committed the file is deleted.
*
* Data compression is supported.
*/
public class ValueLob extends Value {
/**
* This counter is used to calculate the next directory to store lobs. It is
* better than using a random number because less directories are created.
*/
private static int dirCounter;
private final int type;
private long precision;
private DataHandler handler;
private int tableId;
private int objectId;
private String fileName;
private boolean linked;
private byte[] small;
private int hash;
private boolean compressed;
private FileStore tempFile;
private ValueLob(int type, DataHandler handler, String fileName,
int tableId, int objectId, boolean linked, long precision,
boolean compressed) {
this.type = type;
this.handler = handler;
this.fileName = fileName;
this.tableId = tableId;
this.objectId = objectId;
this.linked = linked;
this.precision = precision;
this.compressed = compressed;
}
private ValueLob(int type, byte[] small) {
this.type = type;
this.small = small;
if (small != null) {
if (type == Value.BLOB) {
this.precision = small.length;
} else {
this.precision = getString().length();
}
}
}
private static ValueLob copy(ValueLob lob) {
ValueLob copy = new ValueLob(lob.type, lob.handler, lob.fileName,
lob.tableId, lob.objectId, lob.linked, lob.precision, lob.compressed);
copy.small = lob.small;
copy.hash = lob.hash;
return copy;
}
/**
* Create a small lob using the given byte array.
*
* @param type the type (Value.BLOB or CLOB)
* @param small the byte array
* @return the lob value
*/
private static ValueLob createSmallLob(int type, byte[] small) {
return new ValueLob(type, small);
}
private static String getFileName(DataHandler handler, int tableId,
int objectId) {
if (SysProperties.CHECK && tableId == 0 && objectId == 0) {
DbException.throwInternalError("0 LOB");
}
String table = tableId < 0 ? ".temp" : ".t" + tableId;
return getFileNamePrefix(handler.getDatabasePath(), objectId) +
table + Constants.SUFFIX_LOB_FILE;
}
/**
* Create a LOB value with the given parameters.
*
* @param type the data type
* @param handler the file handler
* @param tableId the table object id
* @param objectId the object id
* @param precision the precision (length in elements)
* @param compression if compression is used
* @return the value object
*/
public static ValueLob openLinked(int type, DataHandler handler,
int tableId, int objectId, long precision, boolean compression) {
String fileName = getFileName(handler, tableId, objectId);
return new ValueLob(type, handler, fileName, tableId, objectId,
true/* linked */, precision, compression);
}
/**
* Create a LOB value with the given parameters.
*
* @param type the data type
* @param handler the file handler
* @param tableId the table object id
* @param objectId the object id
* @param precision the precision (length in elements)
* @param compression if compression is used
* @param fileName the file name
* @return the value object
*/
public static ValueLob openUnlinked(int type, DataHandler handler,
int tableId, int objectId, long precision, boolean compression,
String fileName) {
return new ValueLob(type, handler, fileName, tableId, objectId,
false/* linked */, precision, compression);
}
/**
* Create a CLOB value from a stream.
*
* @param in the reader
* @param length the number of characters to read, or -1 for no limit
* @param handler the data handler
* @return the lob value
*/
private static ValueLob createClob(Reader in, long length,
DataHandler handler) {
try {
if (handler == null) {
String s = IOUtils.readStringAndClose(in, (int) length);
return createSmallLob(Value.CLOB, s.getBytes(Constants.UTF8));
}
boolean compress = handler.getLobCompressionAlgorithm(Value.CLOB) != null;
long remaining = Long.MAX_VALUE;
if (length >= 0 && length < remaining) {
remaining = length;
}
int len = getBufferSize(handler, compress, remaining);
char[] buff;
if (len >= Integer.MAX_VALUE) {
String data = IOUtils.readStringAndClose(in, -1);
buff = data.toCharArray();
len = buff.length;
} else {
buff = new char[len];
len = IOUtils.readFully(in, buff, len);
}
if (len <= handler.getMaxLengthInplaceLob()) {
byte[] small = new String(buff, 0, len).getBytes(Constants.UTF8);
return ValueLob.createSmallLob(Value.CLOB, small);
}
ValueLob lob = new ValueLob(Value.CLOB, null);
lob.createFromReader(buff, len, in, remaining, handler);
return lob;
} catch (IOException e) {
throw DbException.convertIOException(e, null);
}
}
private static int getBufferSize(DataHandler handler, boolean compress,
long remaining) {
if (remaining < 0 || remaining > Integer.MAX_VALUE) {
remaining = Integer.MAX_VALUE;
}
int inplace = handler.getMaxLengthInplaceLob();
long m = compress ?
Constants.IO_BUFFER_SIZE_COMPRESS : Constants.IO_BUFFER_SIZE;
if (m < remaining && m <= inplace) {
// using "1L" to force long arithmetic
m = Math.min(remaining, inplace + 1L);
// the buffer size must be bigger than the inplace lob, otherwise we
// can't know if it must be stored in-place or not
m = MathUtils.roundUpLong(m, Constants.IO_BUFFER_SIZE);
}
m = Math.min(remaining, m);
m = MathUtils.convertLongToInt(m);
if (m < 0) {
m = Integer.MAX_VALUE;
}
return (int) m;
}
private void createFromReader(char[] buff, int len, Reader in,
long remaining, DataHandler h) throws IOException {
FileStoreOutputStream out = initLarge(h);
boolean compress = h.getLobCompressionAlgorithm(Value.CLOB) != null;
try {
while (true) {
precision += len;
byte[] b = new String(buff, 0, len).getBytes(Constants.UTF8);
out.write(b, 0, b.length);
remaining -= len;
if (remaining <= 0) {
break;
}
len = getBufferSize(h, compress, remaining);
len = IOUtils.readFully(in, buff, len);
if (len == 0) {
break;
}
}
} finally {
out.close();
}
}
private static String getFileNamePrefix(String path, int objectId) {
String name;
int f = objectId % SysProperties.LOB_FILES_PER_DIRECTORY;
if (f > 0) {
name = SysProperties.FILE_SEPARATOR + objectId;
} else {
name = "";
}
objectId /= SysProperties.LOB_FILES_PER_DIRECTORY;
while (objectId > 0) {
f = objectId % SysProperties.LOB_FILES_PER_DIRECTORY;
name = SysProperties.FILE_SEPARATOR + f +
Constants.SUFFIX_LOBS_DIRECTORY + name;
objectId /= SysProperties.LOB_FILES_PER_DIRECTORY;
}
name = FileUtils.toRealPath(path +
Constants.SUFFIX_LOBS_DIRECTORY + name);
return name;
}
private static int getNewObjectId(DataHandler h) {
String path = h.getDatabasePath();
if ((path != null) && (path.length() == 0)) {
path = new File(Utils.getProperty("java.io.tmpdir", "."),
SysProperties.PREFIX_TEMP_FILE).getAbsolutePath();
}
int newId = 0;
int lobsPerDir = SysProperties.LOB_FILES_PER_DIRECTORY;
while (true) {
String dir = getFileNamePrefix(path, newId);
String[] list = getFileList(h, dir);
int fileCount = 0;
boolean[] used = new boolean[lobsPerDir];
for (String name : list) {
if (name.endsWith(Constants.SUFFIX_DB_FILE)) {
name = FileUtils.getName(name);
String n = name.substring(0, name.indexOf('.'));
int id;
try {
id = Integer.parseInt(n);
} catch (NumberFormatException e) {
id = -1;
}
if (id > 0) {
fileCount++;
used[id % lobsPerDir] = true;
}
}
}
int fileId = -1;
if (fileCount < lobsPerDir) {
for (int i = 1; i < lobsPerDir; i++) {
if (!used[i]) {
fileId = i;
break;
}
}
}
if (fileId > 0) {
newId += fileId;
invalidateFileList(h, dir);
break;
}
if (newId > Integer.MAX_VALUE / lobsPerDir) {
// this directory path is full: start from zero
newId = 0;
dirCounter = MathUtils.randomInt(lobsPerDir - 1) * lobsPerDir;
} else {
// calculate the directory.
// start with 1 (otherwise we don't know the number of
// directories).
// it doesn't really matter what directory is used, it might as
// well be random (but that would generate more directories):
// int dirId = RandomUtils.nextInt(lobsPerDir - 1) + 1;
int dirId = (dirCounter++ / (lobsPerDir - 1)) + 1;
newId = newId * lobsPerDir;
newId += dirId * lobsPerDir;
}
}
return newId;
}
private static void invalidateFileList(DataHandler h, String dir) {
SmallLRUCache cache = h.getLobFileListCache();
if (cache != null) {
synchronized (cache) {
cache.remove(dir);
}
}
}
private static String[] getFileList(DataHandler h, String dir) {
SmallLRUCache cache = h.getLobFileListCache();
String[] list;
if (cache == null) {
list = FileUtils.newDirectoryStream(dir).toArray(new String[0]);
} else {
synchronized (cache) {
list = cache.get(dir);
if (list == null) {
list = FileUtils.newDirectoryStream(dir).toArray(new String[0]);
cache.put(dir, list);
}
}
}
return list;
}
/**
* Create a BLOB value from a stream.
*
* @param in the input stream
* @param length the number of characters to read, or -1 for no limit
* @param handler the data handler
* @return the lob value
*/
private static ValueLob createBlob(InputStream in, long length,
DataHandler handler) {
try {
if (handler == null) {
byte[] data = IOUtils.readBytesAndClose(in, (int) length);
return createSmallLob(Value.BLOB, data);
}
long remaining = Long.MAX_VALUE;
boolean compress = handler.getLobCompressionAlgorithm(Value.BLOB) != null;
if (length >= 0 && length < remaining) {
remaining = length;
}
int len = getBufferSize(handler, compress, remaining);
byte[] buff;
if (len >= Integer.MAX_VALUE) {
buff = IOUtils.readBytesAndClose(in, -1);
len = buff.length;
} else {
buff = DataUtils.newBytes(len);
len = IOUtils.readFully(in, buff, len);
}
if (len <= handler.getMaxLengthInplaceLob()) {
byte[] small = DataUtils.newBytes(len);
System.arraycopy(buff, 0, small, 0, len);
return ValueLob.createSmallLob(Value.BLOB, small);
}
ValueLob lob = new ValueLob(Value.BLOB, null);
lob.createFromStream(buff, len, in, remaining, handler);
return lob;
} catch (IOException e) {
throw DbException.convertIOException(e, null);
}
}
private FileStoreOutputStream initLarge(DataHandler h) {
this.handler = h;
this.tableId = 0;
this.linked = false;
this.precision = 0;
this.small = null;
this.hash = 0;
String compressionAlgorithm = h.getLobCompressionAlgorithm(type);
this.compressed = compressionAlgorithm != null;
synchronized (h) {
String path = h.getDatabasePath();
if ((path != null) && (path.length() == 0)) {
path = new File(Utils.getProperty("java.io.tmpdir", "."),
SysProperties.PREFIX_TEMP_FILE).getAbsolutePath();
}
objectId = getNewObjectId(h);
fileName = getFileNamePrefix(path, objectId) + Constants.SUFFIX_TEMP_FILE;
tempFile = h.openFile(fileName, "rw", false);
tempFile.autoDelete();
}
FileStoreOutputStream out = new FileStoreOutputStream(tempFile, h,
compressionAlgorithm);
return out;
}
private void createFromStream(byte[] buff, int len, InputStream in,
long remaining, DataHandler h) throws IOException {
FileStoreOutputStream out = initLarge(h);
boolean compress = h.getLobCompressionAlgorithm(Value.BLOB) != null;
try {
while (true) {
precision += len;
out.write(buff, 0, len);
remaining -= len;
if (remaining <= 0) {
break;
}
len = getBufferSize(h, compress, remaining);
len = IOUtils.readFully(in, buff, len);
if (len <= 0) {
break;
}
}
} finally {
out.close();
}
}
/**
* Convert a lob to another data type. The data is fully read in memory
* except when converting to BLOB or CLOB.
*
* @param t the new type
* @return the converted value
*/
@Override
public Value convertTo(int t) {
if (t == type) {
return this;
} else if (t == Value.CLOB) {
ValueLob copy = ValueLob.createClob(getReader(), -1, handler);
return copy;
} else if (t == Value.BLOB) {
ValueLob copy = ValueLob.createBlob(getInputStream(), -1, handler);
return copy;
}
return super.convertTo(t);
}
@Override
public boolean isLinked() {
return linked;
}
/**
* Get the current file name where the lob is saved.
*
* @return the file name or null
*/
public String getFileName() {
return fileName;
}
@Override
public void close() {
if (fileName != null) {
if (tempFile != null) {
tempFile.stopAutoDelete();
tempFile = null;
}
deleteFile(handler, fileName);
}
}
@Override
public void unlink(DataHandler handler) {
if (linked && fileName != null) {
String temp;
// synchronize on the database, to avoid concurrent temp file
// creation / deletion / backup
synchronized (handler) {
temp = getFileName(handler, -1, objectId);
deleteFile(handler, temp);
renameFile(handler, fileName, temp);
tempFile = FileStore.open(handler, temp, "rw");
tempFile.autoDelete();
tempFile.closeSilently();
fileName = temp;
linked = false;
}
}
}
@Override
public Value link(DataHandler h, int tabId) {
if (fileName == null) {
this.tableId = tabId;
return this;
}
if (linked) {
ValueLob copy = ValueLob.copy(this);
copy.objectId = getNewObjectId(h);
copy.tableId = tabId;
String live = getFileName(h, copy.tableId, copy.objectId);
copyFileTo(h, fileName, live);
copy.fileName = live;
copy.linked = true;
return copy;
}
if (!linked) {
this.tableId = tabId;
String live = getFileName(h, tableId, objectId);
if (tempFile != null) {
tempFile.stopAutoDelete();
tempFile = null;
}
renameFile(h, fileName, live);
fileName = live;
linked = true;
}
return this;
}
/**
* Get the current table id of this lob.
*
* @return the table id
*/
@Override
public int getTableId() {
return tableId;
}
/**
* Get the current object id of this lob.
*
* @return the object id
*/
public int getObjectId() {
return objectId;
}
@Override
public int getType() {
return type;
}
@Override
public long getPrecision() {
return precision;
}
@Override
public String getString() {
int len = precision > Integer.MAX_VALUE || precision == 0 ?
Integer.MAX_VALUE : (int) precision;
try {
if (type == Value.CLOB) {
if (small != null) {
return new String(small, Constants.UTF8);
}
return IOUtils.readStringAndClose(getReader(), len);
}
byte[] buff;
if (small != null) {
buff = small;
} else {
buff = IOUtils.readBytesAndClose(getInputStream(), len);
}
return StringUtils.convertBytesToHex(buff);
} catch (IOException e) {
throw DbException.convertIOException(e, fileName);
}
}
@Override
public byte[] getBytes() {
if (type == CLOB) {
// convert hex to string
return super.getBytes();
}
byte[] data = getBytesNoCopy();
return Utils.cloneByteArray(data);
}
@Override
public byte[] getBytesNoCopy() {
if (type == CLOB) {
// convert hex to string
return super.getBytesNoCopy();
}
if (small != null) {
return small;
}
try {
return IOUtils.readBytesAndClose(
getInputStream(), Integer.MAX_VALUE);
} catch (IOException e) {
throw DbException.convertIOException(e, fileName);
}
}
@Override
public int hashCode() {
if (hash == 0) {
if (precision > 4096) {
// TODO: should calculate the hash code when saving, and store
// it in the database file
return (int) (precision ^ (precision >>> 32));
}
if (type == CLOB) {
hash = getString().hashCode();
} else {
hash = Utils.getByteArrayHash(getBytes());
}
}
return hash;
}
@Override
protected int compareSecure(Value v, CompareMode mode) {
if (type == Value.CLOB) {
return Integer.signum(getString().compareTo(v.getString()));
}
byte[] v2 = v.getBytesNoCopy();
return Utils.compareNotNullSigned(getBytes(), v2);
}
@Override
public Object getObject() {
if (type == Value.CLOB) {
return getReader();
}
return getInputStream();
}
@Override
public Reader getReader() {
return IOUtils.getBufferedReader(getInputStream());
}
@Override
public InputStream getInputStream() {
if (fileName == null) {
return new ByteArrayInputStream(small);
}
FileStore store = handler.openFile(fileName, "r", true);
boolean alwaysClose = SysProperties.lobCloseBetweenReads;
return new BufferedInputStream(
new FileStoreInputStream(store, handler, compressed, alwaysClose),
Constants.IO_BUFFER_SIZE);
}
@Override
public void set(PreparedStatement prep, int parameterIndex)
throws SQLException {
long p = getPrecision();
if (p > Integer.MAX_VALUE || p <= 0) {
p = -1;
}
if (type == Value.BLOB) {
prep.setBinaryStream(parameterIndex, getInputStream(), (int) p);
} else {
prep.setCharacterStream(parameterIndex, getReader(), (int) p);
}
}
@Override
public String getSQL() {
String s;
if (type == Value.CLOB) {
s = getString();
return StringUtils.quoteStringSQL(s);
}
byte[] buff = getBytes();
s = StringUtils.convertBytesToHex(buff);
return "X'" + s + "'";
}
@Override
public String getTraceSQL() {
if (small != null && getPrecision() <= SysProperties.MAX_TRACE_DATA_LENGTH) {
return getSQL();
}
StringBuilder buff = new StringBuilder();
if (type == Value.CLOB) {
buff.append("SPACE(").append(getPrecision());
} else {
buff.append("CAST(REPEAT('00', ").append(getPrecision()).append(") AS BINARY");
}
buff.append(" /* ").append(fileName).append(" */)");
return buff.toString();
}
/**
* Get the data if this a small lob value.
*
* @return the data
*/
@Override
public byte[] getSmall() {
return small;
}
@Override
public int getDisplaySize() {
return MathUtils.convertLongToInt(getPrecision());
}
@Override
public boolean equals(Object other) {
return other instanceof ValueLob && compareSecure((Value) other, null) == 0;
}
/**
* Store the lob data to a file if the size of the buffer is larger than the
* maximum size for an in-place lob.
*
* @param h the data handler
*/
public void convertToFileIfRequired(DataHandler h) {
try {
if (small != null && small.length > h.getMaxLengthInplaceLob()) {
boolean compress = h.getLobCompressionAlgorithm(type) != null;
int len = getBufferSize(h, compress, Long.MAX_VALUE);
int tabId = tableId;
if (type == Value.BLOB) {
createFromStream(
DataUtils.newBytes(len), 0, getInputStream(), Long.MAX_VALUE, h);
} else {
createFromReader(
new char[len], 0, getReader(), Long.MAX_VALUE, h);
}
Value v2 = link(h, tabId);
if (SysProperties.CHECK && v2 != this) {
DbException.throwInternalError();
}
}
} catch (IOException e) {
throw DbException.convertIOException(e, null);
}
}
/**
* Check if this lob value is compressed.
*
* @return true if it is
*/
public boolean isCompressed() {
return compressed;
}
private static synchronized void deleteFile(DataHandler handler,
String fileName) {
// synchronize on the database, to avoid concurrent temp file creation /
// deletion / backup
synchronized (handler.getLobSyncObject()) {
FileUtils.delete(fileName);
}
}
private static synchronized void renameFile(DataHandler handler,
String oldName, String newName) {
synchronized (handler.getLobSyncObject()) {
FileUtils.move(oldName, newName);
}
}
private static void copyFileTo(DataHandler h, String sourceFileName,
String targetFileName) {
synchronized (h.getLobSyncObject()) {
try {
IOUtils.copyFiles(sourceFileName, targetFileName);
} catch (IOException e) {
throw DbException.convertIOException(e, null);
}
}
}
@Override
public int getMemory() {
if (small != null) {
return small.length + 104;
}
return 140;
}
/**
* Create an independent copy of this temporary value.
* The file will not be deleted automatically.
*
* @return the value
*/
@Override
public ValueLob copyToTemp() {
ValueLob lob;
if (type == CLOB) {
lob = ValueLob.createClob(getReader(), precision, handler);
} else {
lob = ValueLob.createBlob(getInputStream(), precision, handler);
}
return lob;
}
@Override
public Value convertPrecision(long precision, boolean force) {
if (this.precision <= precision) {
return this;
}
ValueLob lob;
if (type == CLOB) {
lob = ValueLob.createClob(getReader(), precision, handler);
} else {
lob = ValueLob.createBlob(getInputStream(), precision, handler);
}
return lob;
}
}
