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JDBC driver for Google Cloud Spanner.
/*
* Copyright 2019 Google LLC
*
* 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.
*/
package com.google.cloud.spanner.jdbc;
import com.google.common.base.Preconditions;
import com.google.rpc.Code;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Blob;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* Simple {@link Blob} implementation for Google Cloud Spanner. The value is mapped to a byte array
* in memory. The {@link Blob} data type can be used in combination with the BYTES Cloud Spanner
* data type.
*/
class JdbcBlob implements Blob {
private byte[] value = new byte[0];
/** Creates an empty blob. */
JdbcBlob() {}
/** Creates a blob with the specified bytes as its value. */
JdbcBlob(byte[] value) {
this.value = value;
}
private void checkPosition(long pos) {
Preconditions.checkArgument(
pos + 1 <= Integer.MAX_VALUE,
"position larger than " + Integer.MAX_VALUE + " is not supported");
}
private void checkLength(long length) {
Preconditions.checkArgument(
length <= Integer.MAX_VALUE,
"length larger than " + Integer.MAX_VALUE + " is not supported");
}
private void checkPositionPlusLength(long pos, long length) {
Preconditions.checkArgument(
pos + 1 + length <= Integer.MAX_VALUE,
"position+length larger than " + Integer.MAX_VALUE + " is not supported");
}
@Override
public long length() {
return value.length;
}
@Override
public byte[] getBytes(long pos, int length) throws SQLException {
JdbcPreconditions.checkArgument(pos > 0L, "pos must be >= 1");
JdbcPreconditions.checkArgument(length >= 0, "length must be >= 0");
checkPosition(pos);
checkPositionPlusLength(pos, length);
int end = (int) pos + length - 1;
int blobLength = (int) length();
if (end > blobLength) {
length = blobLength - (int) pos + 1;
}
byte[] res = new byte[length];
System.arraycopy(value, (int) pos - 1, res, 0, length);
return res;
}
@Override
public InputStream getBinaryStream() {
return new ByteArrayInputStream(value);
}
@Override
public long position(byte[] pattern, long start) throws SQLException {
JdbcPreconditions.checkArgument(
pattern != null && pattern.length > 0, "pattern must not be empty");
JdbcPreconditions.checkArgument(start > 0L, "start must be >= 1");
checkPosition(start);
for (int outerIndex = (int) start - 1; outerIndex < value.length; outerIndex++) {
int innerIndex = 0;
int valueIndex = outerIndex;
while (valueIndex < value.length
&& innerIndex < pattern.length
&& value[valueIndex] == pattern[innerIndex]) {
innerIndex++;
valueIndex++;
}
if (innerIndex == pattern.length) {
return outerIndex + 1;
}
}
return -1;
}
@Override
public long position(Blob pattern, long start) throws SQLException {
JdbcPreconditions.checkArgument(pattern != null, "pattern must not be empty");
JdbcPreconditions.checkArgument(start > 0L, "start must be >= 1");
checkPosition(start);
byte[] buffer = new byte[1024];
int totalSize = 0;
List totalBytes = new ArrayList<>();
try (InputStream is = pattern.getBinaryStream()) {
int bytesRead;
while ((bytesRead = is.read(buffer)) > -1) {
if (bytesRead == buffer.length) {
totalBytes.add(buffer);
} else {
byte[] dest = new byte[bytesRead];
System.arraycopy(buffer, 0, dest, 0, bytesRead);
totalBytes.add(dest);
}
totalSize += bytesRead;
buffer = new byte[1024];
}
} catch (IOException e) {
throw JdbcSqlExceptionFactory.of("reading blob failed", Code.UNKNOWN, e);
}
byte[] bytePattern = new byte[totalSize];
int index = 0;
for (byte[] b : totalBytes) {
System.arraycopy(b, 0, bytePattern, index, b.length);
index += b.length;
}
return position(bytePattern, start);
}
private void setLength(int length) {
int prevLength = value.length;
byte[] newValue = new byte[length];
System.arraycopy(value, 0, newValue, 0, Math.min(prevLength, newValue.length));
value = newValue;
}
@Override
public int setBytes(long pos, byte[] bytes) throws SQLException {
JdbcPreconditions.checkArgument(bytes != null, "bytes must be non-null");
JdbcPreconditions.checkArgument(pos > 0L, "pos must be >= 1");
checkPosition(pos);
int end = (int) pos + bytes.length - 1;
if (end >= value.length) {
setLength(end);
}
System.arraycopy(bytes, 0, value, (int) pos - 1, bytes.length);
return bytes.length;
}
@Override
public int setBytes(long pos, byte[] bytes, int offset, int len) throws SQLException {
JdbcPreconditions.checkArgument(bytes != null, "bytes must be non-null");
JdbcPreconditions.checkArgument(pos > 0L, "pos must be >= 1");
JdbcPreconditions.checkArgument(offset >= 0, "offset must be >= 0");
JdbcPreconditions.checkArgument(len >= 0, "len must be >= 0");
checkPosition(pos);
if (offset > bytes.length) {
offset = 0;
len = 0;
} else {
if (offset + len > bytes.length) {
len = bytes.length - offset;
}
}
int end = (int) pos + len - 1;
if (end >= value.length) {
setLength(end);
}
System.arraycopy(bytes, offset, value, (int) pos - 1, len);
return len;
}
private final class BlobOutputStream extends OutputStream {
private byte[] buffer = new byte[1024];
private int currentPos = 0;
private int blobPosition;
private BlobOutputStream(int pos) {
blobPosition = pos;
}
@Override
public void write(int b) {
if (currentPos >= buffer.length) {
byte[] newBuffer = new byte[buffer.length * 2];
System.arraycopy(buffer, 0, newBuffer, 0, buffer.length);
buffer = newBuffer;
}
buffer[currentPos] = (byte) b;
currentPos++;
}
@Override
public void flush() throws IOException {
try {
setBytes(blobPosition, buffer, 0, currentPos);
blobPosition += currentPos;
currentPos = 0;
Arrays.fill(buffer, (byte) 0);
} catch (SQLException e) {
throw new IOException(e);
}
}
@Override
public void close() throws IOException {
flush();
}
}
@Override
public OutputStream setBinaryStream(long pos) throws SQLException {
JdbcPreconditions.checkArgument(pos > 0L, "pos must be >= 1");
checkPosition(pos);
return new BlobOutputStream((int) pos);
}
@Override
public void truncate(long len) throws SQLException {
JdbcPreconditions.checkArgument(len >= 0, "len must be >= 0");
checkLength(len);
setLength((int) len);
}
@Override
public void free() {
setLength(0);
}
@Override
public InputStream getBinaryStream(long pos, long length) throws SQLException {
JdbcPreconditions.checkArgument(pos > 0, "pos must be >= 1");
JdbcPreconditions.checkArgument(length >= 0, "length must be >= 0");
checkPosition(pos);
checkPositionPlusLength(pos, length);
if (pos + length > value.length) {
length = value.length - pos + 1;
}
byte[] buffer = new byte[(int) length];
System.arraycopy(value, (int) pos - 1, buffer, 0, (int) length);
return new ByteArrayInputStream(buffer);
}
@Override
public boolean equals(Object other) {
if (!(other instanceof JdbcBlob)) return false;
JdbcBlob blob = (JdbcBlob) other;
return Arrays.equals(this.value, blob.value);
}
@Override
public int hashCode() {
return Arrays.hashCode(value);
}
}
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