mirror of
https://github.com/postgres/postgres.git
synced 2025-08-21 10:42:50 +03:00
Bring in Peter's changes...finally :(
This commit is contained in:
Marc G. Fournier
462
src/interfaces/jdbc/postgresql/PGlobj.java
Normal file
462
src/interfaces/jdbc/postgresql/PGlobj.java
Normal file
@@ -0,0 +1,462 @@
|
||||
// Java Interface to Postgres
|
||||
// $Id: PGlobj.java,v 1.1 1997/09/20 02:21:22 scrappy Exp $
|
||||
|
||||
// Copyright (c) 1997 Peter T Mount
|
||||
|
||||
package postgresql;
|
||||
|
||||
import java.sql.*;
|
||||
import java.math.*;
|
||||
import java.net.*;
|
||||
import java.io.*;
|
||||
import java.util.*;
|
||||
|
||||
/**
|
||||
* This class implements the large object interface to postgresql.
|
||||
*
|
||||
* It provides the basic methods required to run the interface, plus
|
||||
* a pair of methods that provide InputStream and OutputStream classes
|
||||
* for this object.
|
||||
*/
|
||||
public class PGlobj
|
||||
{
|
||||
// This table contains the function oid's used by the backend
|
||||
private Hashtable func = new Hashtable();
|
||||
|
||||
protected postgresql.Connection conn;
|
||||
|
||||
/**
|
||||
* These are the values for mode, taken from libpq-fs.h
|
||||
*/
|
||||
public static final int INV_ARCHIVE = 0x00010000;
|
||||
public static final int INV_WRITE = 0x00020000;
|
||||
public static final int INV_READ = 0x00040000;
|
||||
|
||||
/**
|
||||
* These are the functions that implement the interface
|
||||
*/
|
||||
private static final String OPEN = "lo_open";
|
||||
private static final String CLOSE = "lo_close";
|
||||
private static final String CREATE = "lo_creat";
|
||||
private static final String UNLINK = "lo_unlink";
|
||||
private static final String SEEK = "lo_lseek";
|
||||
private static final String TELL = "lo_tell";
|
||||
private static final String READ = "loread";
|
||||
private static final String WRITE = "lowrite";
|
||||
|
||||
/**
|
||||
* This creates the interface
|
||||
*/
|
||||
public PGlobj(Connection conn) throws SQLException
|
||||
{
|
||||
if(!(conn instanceof postgresql.Connection))
|
||||
throw new SQLException("PGlobj: Wrong connection class");
|
||||
|
||||
this.conn = (postgresql.Connection)conn;
|
||||
ResultSet res = (postgresql.ResultSet)conn.createStatement().executeQuery("select proname, oid from pg_proc" +
|
||||
" where proname = 'lo_open'" +
|
||||
" or proname = 'lo_close'" +
|
||||
" or proname = 'lo_creat'" +
|
||||
" or proname = 'lo_unlink'" +
|
||||
" or proname = 'lo_lseek'" +
|
||||
" or proname = 'lo_tell'" +
|
||||
" or proname = 'loread'" +
|
||||
" or proname = 'lowrite'");
|
||||
|
||||
if(res==null)
|
||||
throw new SQLException("failed to initialise large object interface");
|
||||
|
||||
while(res.next()) {
|
||||
func.put(res.getString(1),new Integer(res.getInt(2)));
|
||||
DriverManager.println("PGlobj:func "+res.getString(1)+" oid="+res.getInt(2));
|
||||
}
|
||||
res.close();
|
||||
}
|
||||
|
||||
// this returns the oid of the function
|
||||
private int getFunc(String name) throws SQLException
|
||||
{
|
||||
Integer i = (Integer)func.get(name);
|
||||
if(i==null)
|
||||
throw new SQLException("unknown function: "+name);
|
||||
return i.intValue();
|
||||
}
|
||||
|
||||
/**
|
||||
* This calls a function on the backend
|
||||
* @param fnid oid of the function to run
|
||||
* @param args array containing args, 3 ints per arg
|
||||
*/
|
||||
public int PQfn(int fnid,int args[]) throws SQLException
|
||||
{
|
||||
return PQfn(fnid,args,null,0,0);
|
||||
}
|
||||
|
||||
// fix bug in 6.1.1
|
||||
public void writeInt(DataOutputStream data,int i) throws IOException
|
||||
{
|
||||
data.writeByte((i>>24)&0xff);
|
||||
data.writeByte( i &0xff);
|
||||
data.writeByte((i>>8) &0xff);
|
||||
data.writeByte((i>>16)&0xff);
|
||||
}
|
||||
|
||||
/**
|
||||
* This calls a function on the backend
|
||||
* @param fnid oid of the function to run
|
||||
* @param args array containing args, 3 ints per arg
|
||||
* @param buf byte array to write into, null returns result as an integer
|
||||
* @param off offset in array
|
||||
* @param len number of bytes to read
|
||||
*/
|
||||
public int PQfn(int fnid,int args[],byte buf[],int off,int len) throws SQLException
|
||||
{
|
||||
//ByteArrayOutputStream b = new ByteArrayOutputStream();
|
||||
//DataOutputStream data = new DataOutputStream(b);
|
||||
int in = -1;
|
||||
|
||||
try {
|
||||
int al=args.length/3;
|
||||
|
||||
// For some reason, the backend takes these in the reverse order
|
||||
byte b[] = new byte[2+4+4];
|
||||
int bp=0;
|
||||
b[bp++]='F';
|
||||
b[bp++]=0;
|
||||
b[bp++]=(byte)((fnid)&0xff);
|
||||
b[bp++]=(byte)((fnid>>24)&0xff);
|
||||
b[bp++]=(byte)((fnid>>16)&0xff);
|
||||
b[bp++]=(byte)((fnid>>8)&0xff);
|
||||
b[bp++]=(byte)((al)&0xff);
|
||||
b[bp++]=(byte)((al>>24)&0xff);
|
||||
b[bp++]=(byte)((al>>16)&0xff);
|
||||
b[bp++]=(byte)((al>>8)&0xff);
|
||||
conn.pg_stream.Send(b);
|
||||
|
||||
//conn.pg_stream.SendChar('F');
|
||||
//conn.pg_stream.SendInteger(fnid,4);
|
||||
//conn.pg_stream.SendInteger(args.length / 3,4);
|
||||
|
||||
int l = args.length-1;
|
||||
if(args[l]==0) l--;
|
||||
|
||||
for(int i=0;i<l;i++)
|
||||
conn.pg_stream.SendInteger(args[i],4);
|
||||
|
||||
if(args[args.length-1]==0)
|
||||
conn.pg_stream.Send(buf,off,len);
|
||||
|
||||
} catch(Exception e) {
|
||||
throw new SQLException("lo_open failed");
|
||||
}
|
||||
//try {
|
||||
if((in = conn.pg_stream.ReceiveChar())!='V') {
|
||||
if(in=='E')
|
||||
throw new SQLException(conn.pg_stream.ReceiveString(4096));
|
||||
throw new SQLException("lobj: expected 'V' from backend, got "+((char)in));
|
||||
}
|
||||
|
||||
while(true) {
|
||||
in = conn.pg_stream.ReceiveChar();
|
||||
switch(in)
|
||||
{
|
||||
case 'G':
|
||||
if(buf==null)
|
||||
in = conn.pg_stream.ReceiveInteger(4);
|
||||
else
|
||||
conn.pg_stream.Receive(buf,off,len);
|
||||
conn.pg_stream.ReceiveChar();
|
||||
return in;
|
||||
|
||||
case 'E':
|
||||
throw new SQLException("lobj: error - "+conn.pg_stream.ReceiveString(4096));
|
||||
|
||||
case 'N':
|
||||
conn.pg_stream.ReceiveString(4096);
|
||||
break;
|
||||
|
||||
case '0':
|
||||
return -1;
|
||||
|
||||
default:
|
||||
throw new SQLException("lobj: protocol error");
|
||||
}
|
||||
}
|
||||
// } catch(IOException ioe) {
|
||||
// throw new SQLException("lobj: Network error - "+ioe);
|
||||
//}
|
||||
}
|
||||
|
||||
/**
|
||||
* This opens a large object. It returns a handle that is used to
|
||||
* access the object.
|
||||
*/
|
||||
public int open(int lobjId,int mode) throws SQLException
|
||||
{
|
||||
int args[] = new int[2*3];
|
||||
args[0] = args[3] = 4;
|
||||
args[1] = args[4] = 1;
|
||||
args[2] = lobjId;
|
||||
args[5] = mode;
|
||||
|
||||
int fd = PQfn(getFunc(OPEN),args);
|
||||
if(fd<0)
|
||||
throw new SQLException("lo_open: no object");
|
||||
seek(fd,0);
|
||||
return fd;
|
||||
}
|
||||
|
||||
/**
|
||||
* This closes a large object.
|
||||
*/
|
||||
public void close(int fd) throws SQLException
|
||||
{
|
||||
int args[] = new int[1*3];
|
||||
args[0] = 4;
|
||||
args[1] = 1;
|
||||
args[2] = fd;
|
||||
|
||||
// flush/close streams here?
|
||||
PQfn(getFunc(CLOSE),args);
|
||||
}
|
||||
|
||||
/**
|
||||
* This reads a block of bytes from the large object
|
||||
* @param fd descriptor for an open large object
|
||||
* @param buf byte array to write into
|
||||
* @param off offset in array
|
||||
* @param len number of bytes to read
|
||||
*/
|
||||
public void read(int fd,byte buf[],int off,int len) throws SQLException
|
||||
{
|
||||
int args[] = new int[2*3];
|
||||
args[0] = args[3] = 4;
|
||||
args[1] = args[4] = 1;
|
||||
args[2] = fd;
|
||||
args[5] = len;
|
||||
|
||||
PQfn(getFunc(READ),args,buf,off,len);
|
||||
}
|
||||
|
||||
/**
|
||||
* This writes a block of bytes to an open large object
|
||||
* @param fd descriptor for an open large object
|
||||
* @param buf byte array to write into
|
||||
* @param off offset in array
|
||||
* @param len number of bytes to read
|
||||
*/
|
||||
public void write(int fd,byte buf[],int off,int len) throws SQLException
|
||||
{
|
||||
int args[] = new int[2*3];
|
||||
args[0] = args[3] = 4;
|
||||
args[1] = args[4] = 1;
|
||||
args[2] = fd;
|
||||
args[5] = 0;
|
||||
|
||||
PQfn(getFunc(WRITE),args,buf,off,len);
|
||||
}
|
||||
|
||||
/**
|
||||
* This sets the current read or write location on a large object.
|
||||
* @param fd descriptor of an open large object
|
||||
* @param off offset in object
|
||||
*/
|
||||
public void seek(int fd,int off) throws SQLException
|
||||
{
|
||||
int args[] = new int[3*3];
|
||||
args[0] = args[3] = args[6] = 4;
|
||||
args[1] = args[4] = args[7] = 1;
|
||||
args[2] = fd;
|
||||
args[5] = off;
|
||||
args[8] = 0; // SEEK
|
||||
|
||||
PQfn(getFunc(SEEK),args);
|
||||
}
|
||||
|
||||
/**
|
||||
* This creates a new large object.
|
||||
*
|
||||
* the mode is a bitmask describing different attributes of the new object
|
||||
*
|
||||
* returns the oid of the large object created.
|
||||
*/
|
||||
public int create(int mode) throws SQLException
|
||||
{
|
||||
int args[] = new int[1*3];
|
||||
args[0] = 4;
|
||||
args[1] = 1;
|
||||
args[2] = mode;
|
||||
|
||||
return PQfn(getFunc(CREATE),args);
|
||||
}
|
||||
|
||||
/**
|
||||
* This returns the current location within the large object
|
||||
*/
|
||||
public int tell(int fd) throws SQLException
|
||||
{
|
||||
int args[] = new int[1*3];
|
||||
args[0] = 4;
|
||||
args[1] = 1;
|
||||
args[2] = fd;
|
||||
|
||||
return PQfn(getFunc(TELL),args);
|
||||
}
|
||||
|
||||
/**
|
||||
* This removes a large object from the database
|
||||
*/
|
||||
public void unlink(int fd) throws SQLException
|
||||
{
|
||||
int args[] = new int[1*3];
|
||||
args[0] = 4;
|
||||
args[1] = 1;
|
||||
args[2] = fd;
|
||||
|
||||
PQfn(getFunc(UNLINK),args);
|
||||
}
|
||||
|
||||
/**
|
||||
* This returns an InputStream based on an object
|
||||
*/
|
||||
public InputStream getInputStream(int fd) throws SQLException
|
||||
{
|
||||
return (InputStream) new PGlobjInput(this,fd);
|
||||
}
|
||||
|
||||
/**
|
||||
* This returns an OutputStream based on an object
|
||||
*/
|
||||
public OutputStream getOutputStream(int fd) throws SQLException
|
||||
{
|
||||
return (OutputStream) new PGlobjOutput(this,fd);
|
||||
}
|
||||
|
||||
/**
|
||||
* As yet, the lo_import and lo_export functions are not implemented.
|
||||
*/
|
||||
}
|
||||
|
||||
// This class implements an InputStream based on a large object
|
||||
//
|
||||
// Note: Unlike most InputStreams, this one supports mark()/reset()
|
||||
//
|
||||
class PGlobjInput extends InputStream
|
||||
{
|
||||
private PGlobj obj;
|
||||
private int fd;
|
||||
|
||||
private int mp; // mark position
|
||||
private int rl; // read limit
|
||||
|
||||
// This creates an Input stream based for a large object
|
||||
public PGlobjInput(PGlobj obj,int fd)
|
||||
{
|
||||
this.obj = obj;
|
||||
this.fd = fd;
|
||||
}
|
||||
|
||||
public int read() throws IOException
|
||||
{
|
||||
byte b[] = new byte[1];
|
||||
read(b,0,1);
|
||||
return (int)b[0];
|
||||
}
|
||||
|
||||
public int read(byte b[],int off,int len) throws IOException
|
||||
{
|
||||
try {
|
||||
obj.read(fd,b,off,len);
|
||||
} catch(SQLException e) {
|
||||
throw new IOException(e.toString());
|
||||
}
|
||||
return len;
|
||||
}
|
||||
|
||||
public long skip(long n) throws IOException
|
||||
{
|
||||
try {
|
||||
int cp = obj.tell(fd);
|
||||
obj.seek(fd,cp+(int)n);
|
||||
return obj.tell(fd) - cp;
|
||||
} catch(SQLException e) {
|
||||
throw new IOException(e.toString());
|
||||
}
|
||||
}
|
||||
|
||||
public synchronized void mark(int readLimit)
|
||||
{
|
||||
try {
|
||||
mp = obj.tell(fd);
|
||||
rl = readLimit;
|
||||
} catch(SQLException e) {
|
||||
// We should throw an exception here, but mark() doesn't ;-(
|
||||
}
|
||||
}
|
||||
|
||||
public void reset() throws IOException
|
||||
{
|
||||
try {
|
||||
int cp = obj.tell(fd);
|
||||
if((cp-mp)>rl)
|
||||
throw new IOException("mark invalidated");
|
||||
obj.seek(fd,mp);
|
||||
} catch(SQLException e) {
|
||||
throw new IOException(e.toString());
|
||||
}
|
||||
}
|
||||
|
||||
public boolean markSupported()
|
||||
{
|
||||
return true;
|
||||
}
|
||||
|
||||
|
||||
public void close() throws IOException
|
||||
{
|
||||
try {
|
||||
obj.close(fd);
|
||||
} catch(SQLException e) {
|
||||
throw new IOException(e.toString());
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// This class implements an OutputStream to a large object
|
||||
class PGlobjOutput extends OutputStream
|
||||
{
|
||||
private PGlobj obj;
|
||||
private int fd;
|
||||
|
||||
// This creates an Input stream based for a large object
|
||||
public PGlobjOutput(PGlobj obj,int fd)
|
||||
{
|
||||
this.obj = obj;
|
||||
this.fd = fd;
|
||||
}
|
||||
|
||||
public void write(int i) throws IOException
|
||||
{
|
||||
byte b[] = new byte[1];
|
||||
b[0] = (byte)i;
|
||||
write(b,0,1);
|
||||
}
|
||||
|
||||
public void write(byte b[],int off,int len) throws IOException
|
||||
{
|
||||
try {
|
||||
obj.write(fd,b,off,len);
|
||||
} catch(SQLException e) {
|
||||
throw new IOException(e.toString());
|
||||
}
|
||||
}
|
||||
|
||||
public void close() throws IOException
|
||||
{
|
||||
try {
|
||||
obj.close(fd);
|
||||
} catch(SQLException e) {
|
||||
throw new IOException(e.toString());
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user