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Honor Blob ranges and independent read cursors #911

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33 changes: 26 additions & 7 deletions src/main/java/org/duckdb/DuckDBResultSet.java
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Original file line number Diff line number Diff line change
Expand Up @@ -455,6 +455,15 @@ public int read() throws IOException {
}

public int read(byte[] bytes, int off, int len) throws IOException {
if (bytes == null) {
throw new NullPointerException();
}
if (off < 0 || len < 0 || len > bytes.length - off) {
throw new IndexOutOfBoundsException();
}
if (len == 0) {
return 0;
}
if (!buf.hasRemaining()) {
return -1;
}
Expand All @@ -472,21 +481,31 @@ public DuckDBBlobResult(ByteBuffer buffer_p) {
}

public InputStream getBinaryStream() {
return getBinaryStream(0, length());
return new ByteBufferBackedInputStream(buffer.duplicate());
}

public InputStream getBinaryStream(long pos, long length) {
return new ByteBufferBackedInputStream(buffer);
public InputStream getBinaryStream(long pos, long length) throws SQLException {
long blobLength = length();
if (pos < 1 || length < 0 || pos - 1 > blobLength || length > blobLength - (pos - 1)) {
throw createSQLException("Invalid position or length", ErrorCode.RESULT_SET_INVALID_POS_LEN);
}
ByteBuffer slice = buffer.duplicate();
slice.position((int) (pos - 1));
slice.limit((int) (pos - 1 + length));
return new ByteBufferBackedInputStream(slice);
}

@Override
public byte[] getBytes(long pos, int length) throws SQLException {
if (pos < 1 || length < 0) {
long blobLength = length();
if (pos < 1 || length < 0 || pos - 1 > blobLength) {
throw createSQLException("Invalid position or length", ErrorCode.RESULT_SET_INVALID_POS_LEN);
}
byte[] bytes = new byte[length];
buffer.position((int) pos - 1);
buffer.get(bytes, 0, length);
int available = (int) Math.min((long) length, blobLength - (pos - 1));
byte[] bytes = new byte[available];
ByteBuffer dup = buffer.duplicate();
dup.position((int) (pos - 1));
dup.get(bytes, 0, available);
return bytes;
}

Expand Down
91 changes: 91 additions & 0 deletions src/test/java/org/duckdb/TestDuckDBJDBC.java
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,8 @@
import static org.duckdb.test.Runner.runTests;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.StringReader;
import java.math.BigDecimal;
import java.math.BigInteger;
Expand Down Expand Up @@ -2007,6 +2009,95 @@ public static void test_blob_after_rs_next() throws Exception {
}
}

private static byte[] readAll(InputStream in) throws Exception {
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] buf = new byte[8];
int n;
while ((n = in.read(buf, 0, buf.length)) != -1) {
out.write(buf, 0, n);
}
return out.toByteArray();
}

public static void test_blob_binary_stream_slice() throws Exception {
try (Connection conn = DriverManager.getConnection(JDBC_URL); Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT 'ABCDEF'::BLOB")) {
assertTrue(rs.next());
Blob blob = rs.getBlob(1);
// 1-based pos with an exact bounded length yields just the requested slice
assertEquals(new String(readAll(blob.getBinaryStream(2, 3)), US_ASCII), "BCD");
// whole-blob stream still sees everything
assertEquals(new String(readAll(blob.getBinaryStream()), US_ASCII), "ABCDEF");
// bounded slice from the first byte spanning the whole blob
assertEquals(new String(readAll(blob.getBinaryStream(1, blob.length())), US_ASCII), "ABCDEF");
}
}

public static void test_blob_streams_independent_cursors() throws Exception {
try (Connection conn = DriverManager.getConnection(JDBC_URL); Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT 'ABCDEF'::BLOB")) {
assertTrue(rs.next());
Blob blob = rs.getBlob(1);
InputStream first = blob.getBinaryStream();
InputStream second = blob.getBinaryStream();
// Advancing one stream must not move the other
assertEquals(first.read(), (int) 'A');
assertEquals(second.read(), (int) 'A');
assertEquals(first.read(), (int) 'B');
assertEquals(second.read(), (int) 'B');
// getBytes must not disturb either stream's cursor
assertEquals(new String(blob.getBytes(1, (int) blob.length()), US_ASCII), "ABCDEF");
assertEquals(first.read(), (int) 'C');
assertEquals(second.read(), (int) 'C');
assertEquals(new String(readAll(first), US_ASCII), "DEF");
assertEquals(new String(readAll(second), US_ASCII), "DEF");
}
}

public static void test_blob_get_bytes_overlength() throws Exception {
try (Connection conn = DriverManager.getConnection(JDBC_URL); Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT 'ABCDEF'::BLOB")) {
assertTrue(rs.next());
Blob blob = rs.getBlob(1);
// Over-length is clipped to the remaining bytes per JDBC
assertEquals(new String(blob.getBytes(2, 100), US_ASCII), "BCDEF");
assertEquals(new String(blob.getBytes(1, 100), US_ASCII), "ABCDEF");
// Zero-length read returns 0 even at EOF; an empty range yields an empty array/stream
InputStream empty = blob.getBinaryStream(1, 0);
assertEquals(empty.read(new byte[4], 0, 0), 0);
assertEquals(empty.read(new byte[4], 0, 4), -1);
assertEquals(blob.getBytes(1, 0).length, 0);
// Empty blob supports an empty whole-blob stream
assertEquals(new String(readAll(blobOf("").getBinaryStream()), US_ASCII), "");
}
}

public static void test_blob_invalid_pos_len() throws Exception {
try (Connection conn = DriverManager.getConnection(JDBC_URL); Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT 'ABCDEF'::BLOB")) {
assertTrue(rs.next());
Blob blob = rs.getBlob(1);
assertThrows(() -> blob.getBytes(0, 1), SQLException.class);
assertThrows(() -> blob.getBytes(1, -1), SQLException.class);
assertThrows(() -> blob.getBinaryStream(0, 1), SQLException.class);
assertThrows(() -> blob.getBinaryStream(1, -1), SQLException.class);
assertThrows(() -> blob.getBinaryStream(2, 100), SQLException.class);
// Extreme positions/lengths must not silently wrap
assertThrows(() -> blob.getBytes(Long.MAX_VALUE, 1), SQLException.class);
assertThrows(() -> blob.getBinaryStream(Long.MAX_VALUE, 1), SQLException.class);
assertThrows(() -> blob.getBinaryStream(1, Long.MAX_VALUE), SQLException.class);
}
}

public static void test_blob_stream_read_arg_validation() throws Exception {
// Even at EOF / on a zero-length blob stream, read(byte[], int, int) must
// validate its arguments before reporting -1.
Blob empty = blobOf("");
InputStream stream = empty.getBinaryStream();
assertThrows(() -> stream.read(null, 0, 0), NullPointerException.class);
assertThrows(() -> stream.read(new byte[1], 2, 0), IndexOutOfBoundsException.class);
}

public static void test_typed_connection_properties() throws Exception {
Properties config = new Properties();
config.put("autoinstall_known_extensions", false); // BOOLEAN
Expand Down
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