Tue Jan 30 22:24:00 GMT 2001 peter@retep.org.uk

- Fixed bug where Statement.setMaxRows() was a global setting. Now
          limited to just itself.
        - Changed LargeObject.read(byte[],int,int) to return the actual number
          of bytes read (used to be void).
        - LargeObject now supports InputStream's!
        - PreparedStatement.setBinaryStream() now works!
        - ResultSet.getBinaryStream() now returns an InputStream that doesn't
          copy the blob into memory first!
        - Connection.isClosed() now tests to see if the connection is still alive
          rather than if it thinks it's alive.
This commit is contained in:
Peter Mount 2001-01-31 08:26:02 +00:00
parent dca0762efc
commit 8439a83d84
12 changed files with 442 additions and 97 deletions

View File

@ -1,3 +1,14 @@
Tue Jan 30 22:24:00 GMT 2001 peter@retep.org.uk
- Fixed bug where Statement.setMaxRows() was a global setting. Now
limited to just itself.
- Changed LargeObject.read(byte[],int,int) to return the actual number
of bytes read (used to be void).
- LargeObject now supports InputStream's!
- PreparedStatement.setBinaryStream() now works!
- ResultSet.getBinaryStream() now returns an InputStream that doesn't
copy the blob into memory first!
- Connection.isClosed() now tests to see if the connection is still alive
rather than if it thinks it's alive.
Thu Jan 25 09:11:00 GMT 2001 peter@retep.org.uk
- Added an alternative constructor to PGSQLException so that debugging
some more osteric bugs is easier. If only 1 arg is supplied and it's

View File

@ -6,7 +6,7 @@ import java.text.*;
/**
*
* $Id: basic.java,v 1.5 2000/06/06 11:05:57 peter Exp $
* $Id: basic.java,v 1.6 2001/01/31 08:26:01 peter Exp $
*
* This example tests the basic components of the JDBC driver, and shows
* how even the simplest of queries can be implemented.
@ -22,40 +22,40 @@ public class basic
{
Connection db; // The connection to the database
Statement st; // Our statement to run queries with
public basic(String args[]) throws ClassNotFoundException, FileNotFoundException, IOException, SQLException
{
String url = args[0];
String usr = args[1];
String pwd = args[2];
// Load the driver
Class.forName("org.postgresql.Driver");
// Connect to database
System.out.println("Connecting to Database URL = " + url);
db = DriverManager.getConnection(url, usr, pwd);
System.out.println("Connected...Now creating a statement");
st = db.createStatement();
// Clean up the database (in case we failed earlier) then initialise
cleanup();
// Now run tests using JDBC methods
doexample();
// Clean up the database
cleanup();
// Finally close the database
System.out.println("Now closing the connection");
st.close();
db.close();
//throw postgresql.Driver.notImplemented();
}
/**
* This drops the table (if it existed). No errors are reported.
*/
@ -67,35 +67,36 @@ public class basic
// We ignore any errors here
}
}
/**
* This performs the example
*/
public void doexample() throws SQLException
{
System.out.println("\nRunning tests:");
// First we need a table to store data in
st.executeUpdate("create table basic (a int2, b int2)");
// Now insert some data, using the Statement
st.executeUpdate("insert into basic values (1,1)");
st.executeUpdate("insert into basic values (2,1)");
st.executeUpdate("insert into basic values (3,1)");
// This shows how to get the oid of a just inserted row
// updated for 7.1
st.executeUpdate("insert into basic values (4,1)");
int insertedOID = ((org.postgresql.ResultSet)st.getResultSet()).getInsertedOID();
int insertedOID = ((org.postgresql.jdbc2.Statement)st).getInsertedOID();
System.out.println("Inserted row with oid "+insertedOID);
// Now change the value of b from 1 to 8
st.executeUpdate("update basic set b=8");
System.out.println("Updated "+st.getUpdateCount()+" rows");
// Now delete 2 rows
st.executeUpdate("delete from basic where a<3");
System.out.println("deleted "+st.getUpdateCount()+" rows");
// For large inserts, a PreparedStatement is more efficient, because it
// supports the idea of precompiling the SQL statement, and to store
// directly, a Java object into any column. PostgreSQL doesnt support
@ -112,7 +113,7 @@ public class basic
ps.executeUpdate(); // executeUpdate because insert returns no data
}
ps.close(); // Always close when we are done with it
// Finally perform a query on the table
System.out.println("performing a query");
ResultSet rs = st.executeQuery("select a, b from basic");
@ -126,7 +127,7 @@ public class basic
}
rs.close(); // again, you must close the result when done
}
// Now run the query again, showing a more efficient way of getting the
// result if you don't know what column number a value is in
System.out.println("performing another query");
@ -140,7 +141,7 @@ public class basic
//
int col_a = rs.findColumn("a");
int col_b = rs.findColumn("b");
// Now we run through the result set, printing out the result.
// Again, we must call .next() before attempting to read any results
while(rs.next()) {
@ -150,11 +151,22 @@ public class basic
}
rs.close(); // again, you must close the result when done
}
// Now test maxrows by setting it to 3 rows
st.setMaxRows(3);
System.out.println("performing a query limited to "+st.getMaxRows());
rs = st.executeQuery("select a, b from basic");
while(rs.next()) {
int a = rs.getInt("a"); // This shows how to get the value by name
int b = rs.getInt(2); // This shows how to get the value by column
System.out.println(" a="+a+" b="+b);
}
rs.close(); // again, you must close the result when done
// The last thing to do is to drop the table. This is done in the
// cleanup() method.
}
/**
* Display some instructions on how to run the example
*/
@ -164,22 +176,22 @@ public class basic
System.out.println("Useage:\n java example.basic jdbc:postgresql:database user password [debug]\n\nThe debug field can be anything. It's presence will enable DriverManager's\ndebug trace. Unless you want to see screens of items, don't put anything in\nhere.");
System.exit(1);
}
/**
* This little lot starts the test
*/
public static void main(String args[])
{
System.out.println("PostgreSQL basic test v6.3 rev 1\n");
if(args.length<3)
instructions();
// This line outputs debug information to stderr. To enable this, simply
// add an extra parameter to the command line
if(args.length>3)
DriverManager.setLogStream(System.err);
// Now run the tests
try {
basic test = new basic(args);

View File

@ -9,7 +9,7 @@
<property category="sys" name="CheckStable" value="1" />
<property category="sys" name="Company" value="" />
<property category="sys" name="Copyright" value="Copyright (c) 2001" />
<property category="sys" name="DefaultPackage" value="org.postgresql.core" />
<property category="sys" name="DefaultPackage" value="org.postgresql.largeobject" />
<property category="sys" name="Description" value="" />
<property category="sys" name="DocPath" value="doc" />
<property category="sys" name="ExcludeClassEnabled" value="0" />

View File

@ -10,7 +10,7 @@ import org.postgresql.largeobject.*;
import org.postgresql.util.*;
/**
* $Id: Connection.java,v 1.13 2001/01/18 17:37:12 peter Exp $
* $Id: Connection.java,v 1.14 2001/01/31 08:26:01 peter Exp $
*
* This abstract class is used by org.postgresql.Driver to open either the JDBC1 or
* JDBC2 versions of the Connection class.
@ -22,7 +22,7 @@ public abstract class Connection
public PG_Stream pg_stream;
// This is set by org.postgresql.Statement.setMaxRows()
public int maxrows = 0; // maximum no. of rows; 0 = unlimited
//public int maxrows = 0; // maximum no. of rows; 0 = unlimited
private String PG_HOST;
private int PG_PORT;
@ -414,6 +414,11 @@ public abstract class Connection
*/
public java.sql.ResultSet ExecSQL(String sql,java.sql.Statement stat) throws SQLException
{
// added Jan 30 2001 to correct maxrows per statement
int maxrows=0;
if(stat!=null)
maxrows=stat.getMaxRows();
// added Oct 7 1998 to give us thread safety.
synchronized(pg_stream) {
// Deallocate all resources in the stream associated

View File

@ -29,6 +29,7 @@ public class Statement implements java.sql.Statement
SQLWarning warnings = null; // The warnings chain.
int timeout = 0; // The timeout for a query (not used)
boolean escapeProcessing = true;// escape processing flag
int maxrows=0;
/**
* Constructor for a Statement. It simply sets the connection
@ -129,7 +130,7 @@ public class Statement implements java.sql.Statement
*/
public int getMaxRows() throws SQLException
{
return connection.maxrows;
return maxrows;
}
/**
@ -141,7 +142,7 @@ public class Statement implements java.sql.Statement
*/
public void setMaxRows(int max) throws SQLException
{
connection.maxrows = max;
maxrows = max;
}
/**

View File

@ -17,7 +17,7 @@ import org.postgresql.largeobject.*;
import org.postgresql.util.*;
/**
* $Id: Connection.java,v 1.5 2001/01/18 17:37:14 peter Exp $
* $Id: Connection.java,v 1.6 2001/01/31 08:26:02 peter Exp $
*
* A Connection represents a session with a specific database. Within the
* context of a Connection, SQL statements are executed and results are
@ -265,7 +265,27 @@ public class Connection extends org.postgresql.Connection implements java.sql.Co
*/
public boolean isClosed() throws SQLException
{
return (pg_stream == null);
// If the stream is gone, then close() was called
if(pg_stream == null)
return true;
// ok, test the connection
try {
// by sending an empty query. If we are dead, then an SQLException should
// be thrown
java.sql.ResultSet rs = ExecSQL(" ");
if(rs!=null)
rs.close();
// By now, we must be alive
return false;
} catch(SQLException se) {
// Why throw an SQLException as this may fail without throwing one,
// ie isClosed() is called incase the connection has died, and we don't
// want to find out by an Exception, so instead we return true, as its
// most likely why it was thrown in the first place.
return true;
}
}
/**

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@ -23,13 +23,13 @@ import org.postgresql.util.*;
* parameter. For instance, if the IN parameter has SQL type Integer, then
* setInt should be used.
*
* <p>If arbitrary parameter type conversions are required, then the setObject
* <p>If arbitrary parameter type conversions are required, then the setObject
* method should be used with a target SQL type.
*
* @see ResultSet
* @see java.sql.PreparedStatement
*/
public class PreparedStatement extends Statement implements java.sql.PreparedStatement
public class PreparedStatement extends Statement implements java.sql.PreparedStatement
{
String sql;
String[] templateStrings;
@ -124,7 +124,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
}
s.append(templateStrings[inStrings.length]);
return super.executeUpdate(s.toString()); // in Statement class
}
}
/**
* Set a parameter to SQL NULL
@ -264,7 +264,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
else {
StringBuffer b = new StringBuffer();
int i;
b.append('\'');
for (i = 0 ; i < x.length() ; ++i)
{
@ -327,7 +327,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
//
//set(parameterIndex, df.format(new java.util.Date(x.getTime()+86400000)));
}
/**
* Set a parameter to a java.sql.Time value. The driver converts
* this to a SQL TIME value when it sends it to the database.
@ -406,7 +406,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
* When a very large binary value is input to a LONGVARBINARY parameter,
* it may be more practical to send it via a java.io.InputStream.
* JDBC will read the data from the stream as needed, until it reaches
* end-of-file.
* end-of-file.
*
* <P><B>Note:</B> This stream object can either be a standard Java
* stream object or your own subclass that implements the standard
@ -418,7 +418,25 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
*/
public void setBinaryStream(int parameterIndex, InputStream x, int length) throws SQLException
{
throw new PSQLException("postgresql.prep.is");
LargeObjectManager lom = connection.getLargeObjectAPI();
int oid = lom.create();
LargeObject lob = lom.open(oid);
OutputStream los = lob.getOutputStream();
try {
// could be buffered, but then the OutputStream returned by LargeObject
// is buffered internally anyhow, so there would be no performance
// boost gained, if anything it would be worse!
int c=x.read();
while(c>-1) {
los.write(c);
c=x.read();
}
los.close();
} catch(IOException se) {
throw new PSQLException("postgresql.prep.is",se);
}
// lob is closed by the stream so don't call lob.close()
setInt(parameterIndex,oid);
}
/**
@ -453,7 +471,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
* @param x the object containing the input parameter value
* @param targetSqlType The SQL type to be send to the database
* @param scale For java.sql.Types.DECIMAL or java.sql.Types.NUMERIC
* types this is the number of digits after the decimal. For
* types this is the number of digits after the decimal. For
* all other types this value will be ignored.
* @exception SQLException if a database access error occurs
*/
@ -501,7 +519,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
{
setObject(parameterIndex, x, targetSqlType, 0);
}
/**
* This stores an Object into a parameter.
* <p>New for 6.4, if the object is not recognised, but it is
@ -542,7 +560,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
/**
* Some prepared statements return multiple results; the execute method
* handles these complex statements as well as the simpler form of
* handles these complex statements as well as the simpler form of
* statements handled by executeQuery and executeUpdate
*
* @return true if the next result is a ResultSet; false if it is an
@ -584,11 +602,11 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
s.append(templateStrings[inStrings.length]);
return s.toString();
}
// **************************************************************
// END OF PUBLIC INTERFACE
// END OF PUBLIC INTERFACE
// **************************************************************
/**
* There are a lot of setXXX classes which all basically do
* the same thing. We need a method which actually does the
@ -604,62 +622,62 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
throw new PSQLException("postgresql.prep.range");
inStrings[paramIndex - 1] = s;
}
// ** JDBC 2 Extensions **
public void addBatch() throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public java.sql.ResultSetMetaData getMetaData() throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public void setArray(int i,Array x) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public void setBlob(int i,Blob x) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public void setCharacterStream(int i,java.io.Reader x,int length) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public void setClob(int i,Clob x) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public void setNull(int i,int t,String s) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public void setRef(int i,Ref x) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public void setDate(int i,java.sql.Date d,java.util.Calendar cal) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public void setTime(int i,Time t,java.util.Calendar cal) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
public void setTimestamp(int i,Timestamp t,java.util.Calendar cal) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
}
}

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@ -581,6 +581,15 @@ public class ResultSet extends org.postgresql.ResultSet implements java.sql.Resu
*/
public InputStream getBinaryStream(int columnIndex) throws SQLException
{
// New in 7.1 Handle OID's as BLOBS so return the input stream
if(!wasNullFlag)
if( fields[columnIndex - 1].getOID() == 26) {
LargeObjectManager lom = connection.getLargeObjectAPI();
LargeObject lob = lom.open(getInt(columnIndex));
return lob.getInputStream();
}
// Not an OID so fake the stream
byte b[] = getBytes(columnIndex);
if (b != null)

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@ -32,6 +32,7 @@ public class Statement implements java.sql.Statement
private Vector batch=null;
int resultsettype; // the resultset type to return
int concurrency; // is it updateable or not?
int maxrows=0; // the maximum number of rows to return 0=unlimited
/**
* Constructor for a Statement. It simply sets the connection
@ -134,7 +135,7 @@ public class Statement implements java.sql.Statement
*/
public int getMaxRows() throws SQLException
{
return connection.maxrows;
return maxrows;
}
/**
@ -146,7 +147,7 @@ public class Statement implements java.sql.Statement
*/
public void setMaxRows(int max) throws SQLException
{
connection.maxrows = max;
maxrows = max;
}
/**
@ -274,7 +275,8 @@ public class Statement implements java.sql.Statement
if(escapeProcessing)
sql=connection.EscapeSQL(sql);
result = connection.ExecSQL(sql);
// New in 7.1, pass Statement so that ExecSQL can customise to it
result = connection.ExecSQL(sql,this);
// New in 7.1, required for ResultSet.getStatement() to work
((org.postgresql.jdbc2.ResultSet)result).setStatement(this);
@ -388,11 +390,6 @@ public class Statement implements java.sql.Statement
throw org.postgresql.Driver.notImplemented();
}
//public int getKeysetSize() throws SQLException
//{
// throw org.postgresql.Driver.notImplemented();
//}
public int getResultSetConcurrency() throws SQLException
{
// new in 7.1
@ -415,11 +412,6 @@ public class Statement implements java.sql.Statement
throw org.postgresql.Driver.notImplemented();
}
//public void setKeysetSize(int keys) throws SQLException
//{
// throw org.postgresql.Driver.notImplemented();
//}
public void setResultSetConcurrency(int value) throws SQLException
{
concurrency=value;
@ -430,4 +422,17 @@ public class Statement implements java.sql.Statement
resultsettype=value;
}
/**
* New in 7.1: Returns the Last inserted oid. This should be used, rather
* than the old method using getResultSet, which for executeUpdate returns
* null.
* @return OID of last insert
*/
public int getInsertedOID() throws SQLException
{
if(result!=null)
return ((org.postgresql.ResultSet)result).getInsertedOID();
return 0;
}
}

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@ -0,0 +1,156 @@
package org.postgresql.largeobject;
import java.io.InputStream;
import java.io.IOException;
import java.sql.SQLException;
/**
* This is an initial implementation of an InputStream from a large object.
* For now, the bare minimum is implemented. Later (after 7.1) we will overide
* the other read methods to optimise them.
*/
public class BlobInputStream extends InputStream {
/**
* The parent LargeObject
*/
private LargeObject lo;
/**
* Buffer used to improve performance
*/
private byte[] buffer;
/**
* Position within buffer
*/
private int bpos;
/**
* The buffer size
*/
private int bsize;
/**
* The mark position
*/
private int mpos=0;
/**
* @param lo LargeObject to read from
*/
public BlobInputStream(LargeObject lo) {
this(lo,1024);
}
/**
* @param lo LargeObject to read from
* @param bsize buffer size
*/
public BlobInputStream(LargeObject lo,int bsize) {
this.lo=lo;
buffer=null;
bpos=0;
this.bsize=bsize;
}
/**
* The minimum required to implement input stream
*/
public int read() throws java.io.IOException {
try {
if(buffer==null || bpos>=buffer.length) {
buffer=lo.read(bsize);
bpos=0;
}
// Handle EOF
if(bpos>=buffer.length)
return -1;
return (int) buffer[bpos++];
} catch(SQLException se) {
throw new IOException(se.toString());
}
}
/**
* Closes this input stream and releases any system resources associated
* with the stream.
*
* <p> The <code>close</code> method of <code>InputStream</code> does
* nothing.
*
* @exception IOException if an I/O error occurs.
*/
public void close() throws IOException {
try {
lo.close();
lo=null;
} catch(SQLException se) {
throw new IOException(se.toString());
}
}
/**
* Marks the current position in this input stream. A subsequent call to
* the <code>reset</code> method repositions this stream at the last marked
* position so that subsequent reads re-read the same bytes.
*
* <p> The <code>readlimit</code> arguments tells this input stream to
* allow that many bytes to be read before the mark position gets
* invalidated.
*
* <p> The general contract of <code>mark</code> is that, if the method
* <code>markSupported</code> returns <code>true</code>, the stream somehow
* remembers all the bytes read after the call to <code>mark</code> and
* stands ready to supply those same bytes again if and whenever the method
* <code>reset</code> is called. However, the stream is not required to
* remember any data at all if more than <code>readlimit</code> bytes are
* read from the stream before <code>reset</code> is called.
*
* <p> The <code>mark</code> method of <code>InputStream</code> does
* nothing.
*
* @param readlimit the maximum limit of bytes that can be read before
* the mark position becomes invalid.
* @see java.io.InputStream#reset()
*/
public synchronized void mark(int readlimit) {
try {
mpos=lo.tell();
} catch(SQLException se) {
//throw new IOException(se.toString());
}
}
/**
* Repositions this stream to the position at the time the
* <code>mark</code> method was last called on this input stream.
* NB: If mark is not called we move to the begining.
* @see java.io.InputStream#mark(int)
* @see java.io.IOException
*/
public synchronized void reset() throws IOException {
try {
lo.seek(mpos);
} catch(SQLException se) {
throw new IOException(se.toString());
}
}
/**
* Tests if this input stream supports the <code>mark</code> and
* <code>reset</code> methods. The <code>markSupported</code> method of
* <code>InputStream</code> returns <code>false</code>.
*
* @return <code>true</code> if this true type supports the mark and reset
* method; <code>false</code> otherwise.
* @see java.io.InputStream#mark(int)
* @see java.io.InputStream#reset()
*/
public boolean markSupported() {
return true;
}
}

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@ -0,0 +1,102 @@
package org.postgresql.largeobject;
import java.io.IOException;
import java.io.OutputStream;
import java.sql.SQLException;
/**
* This implements a basic output stream that writes to a LargeObject
*/
public class BlobOutputStream extends OutputStream {
/**
* The parent LargeObject
*/
private LargeObject lo;
/**
* Buffer
*/
private byte buf[];
/**
* Size of the buffer (default 1K)
*/
private int bsize;
/**
* Position within the buffer
*/
private int bpos;
/**
* Create an OutputStream to a large object
* @param lo LargeObject
*/
public BlobOutputStream(LargeObject lo) {
this(lo,1024);
}
/**
* Create an OutputStream to a large object
* @param lo LargeObject
* @param bsize The size of the buffer used to improve performance
*/
public BlobOutputStream(LargeObject lo,int bsize) {
this.lo=lo;
this.bsize=bsize;
buf=new byte[bsize];
bpos=0;
}
public void write(int b) throws java.io.IOException {
try {
if(bpos>=bsize) {
lo.write(buf);
bpos=0;
}
buf[bpos++]=(byte)b;
} catch(SQLException se) {
throw new IOException(se.toString());
}
}
/**
* Flushes this output stream and forces any buffered output bytes
* to be written out. The general contract of <code>flush</code> is
* that calling it is an indication that, if any bytes previously
* written have been buffered by the implementation of the output
* stream, such bytes should immediately be written to their
* intended destination.
*
* @exception IOException if an I/O error occurs.
*/
public void flush() throws IOException {
try {
if(bpos>0)
lo.write(buf,0,bpos);
bpos=0;
} catch(SQLException se) {
throw new IOException(se.toString());
}
}
/**
* Closes this output stream and releases any system resources
* associated with this stream. The general contract of <code>close</code>
* is that it closes the output stream. A closed stream cannot perform
* output operations and cannot be reopened.
* <p>
* The <code>close</code> method of <code>OutputStream</code> does nothing.
*
* @exception IOException if an I/O error occurs.
*/
public void close() throws IOException {
try {
lo.close();
lo=null;
} catch(SQLException se) {
throw new IOException(se.toString());
}
}
}

View File

@ -16,7 +16,7 @@ import org.postgresql.fastpath.*;
* for this object.
*
* <p>Normally, client code would use the getAsciiStream, getBinaryStream,
* or getUnicodeStream methods in ResultSet, or setAsciiStream,
* or getUnicodeStream methods in ResultSet, or setAsciiStream,
* setBinaryStream, or setUnicodeStream methods in PreparedStatement to
* access Large Objects.
*
@ -47,21 +47,21 @@ public class LargeObject
* Indicates a seek from the begining of a file
*/
public static final int SEEK_SET = 0;
/**
* Indicates a seek from the current position
*/
public static final int SEEK_CUR = 1;
/**
* Indicates a seek from the end of a file
*/
public static final int SEEK_END = 2;
private Fastpath fp; // Fastpath API to use
private int oid; // OID of this object
private int fd; // the descriptor of the open large object
/**
* This opens a large object.
*
@ -78,13 +78,13 @@ public class LargeObject
{
this.fp = fp;
this.oid = oid;
FastpathArg args[] = new FastpathArg[2];
args[0] = new FastpathArg(oid);
args[1] = new FastpathArg(mode);
this.fd = fp.getInteger("lo_open",args);
}
/**
* @return the OID of this LargeObject
*/
@ -92,7 +92,7 @@ public class LargeObject
{
return oid;
}
/**
* This method closes the object. You must not call methods in this
* object after this is called.
@ -104,7 +104,7 @@ public class LargeObject
args[0] = new FastpathArg(fd);
fp.fastpath("lo_close",false,args); // true here as we dont care!!
}
/**
* Reads some data from the object, and return as a byte[] array
*
@ -120,7 +120,7 @@ public class LargeObject
args[0] = new FastpathArg(fd);
args[1] = new FastpathArg(len);
return fp.getData("loread",args);
// This version allows us to break this down into 4k blocks
//if(len<=4048) {
//// handle as before, return the whole block in one go
@ -145,20 +145,25 @@ public class LargeObject
//return buf;
//}
}
/**
* Reads some data from the object into an existing array
*
* @param buf destination array
* @param off offset within array
* @param len number of bytes to read
* @return the number of bytes actually read
* @exception SQLException if a database-access error occurs.
*/
public void read(byte buf[],int off,int len) throws SQLException
public int read(byte buf[],int off,int len) throws SQLException
{
System.arraycopy(read(len),0,buf,off,len);
byte b[] = read(len);
if(b.length<len)
len=b.length;
System.arraycopy(b,0,buf,off,len);
return len;
}
/**
* Writes an array to the object
*
@ -172,7 +177,7 @@ public class LargeObject
args[1] = new FastpathArg(buf);
fp.fastpath("lowrite",false,args);
}
/**
* Writes some data from an array to the object
*
@ -187,7 +192,7 @@ public class LargeObject
System.arraycopy(buf,off,data,0,len);
write(data);
}
/**
* Sets the current position within the object.
*
@ -206,7 +211,7 @@ public class LargeObject
args[2] = new FastpathArg(ref);
fp.fastpath("lo_lseek",false,args);
}
/**
* Sets the current position within the object.
*
@ -220,7 +225,7 @@ public class LargeObject
{
seek(pos,SEEK_SET);
}
/**
* @return the current position within the object
* @exception SQLException if a database-access error occurs.
@ -231,7 +236,7 @@ public class LargeObject
args[0] = new FastpathArg(fd);
return fp.getInteger("lo_tell",args);
}
/**
* This method is inefficient, as the only way to find out the size of
* the object is to seek to the end, record the current position, then
@ -250,7 +255,7 @@ public class LargeObject
seek(cp,SEEK_SET);
return sz;
}
/**
* Returns an InputStream from this object.
*
@ -261,9 +266,9 @@ public class LargeObject
*/
public InputStream getInputStream() throws SQLException
{
throw org.postgresql.Driver.notImplemented();
return new BlobInputStream(this);
}
/**
* Returns an OutputStream to this object
*
@ -274,6 +279,7 @@ public class LargeObject
*/
public OutputStream getOutputStream() throws SQLException
{
throw org.postgresql.Driver.notImplemented();
return new BlobOutputStream(this);
}
}