From fa67a247cf66ea86f6fcc773c27cfd4698d2405a Mon Sep 17 00:00:00 2001
From: "Marc G. Fournier" <scrappy@hub.org>
Date: Sat, 20 Sep 1997 02:21:25 +0000
Subject: Bring in Peter's changes...finally :(

---
 src/interfaces/jdbc/postgresql/PGlobj.java | 462 +++++++++++++++++++++++++++++
 1 file changed, 462 insertions(+)
 create mode 100644 src/interfaces/jdbc/postgresql/PGlobj.java

(limited to 'src/interfaces/jdbc/postgresql/PGlobj.java')

diff --git a/src/interfaces/jdbc/postgresql/PGlobj.java b/src/interfaces/jdbc/postgresql/PGlobj.java
new file mode 100644
index 00000000000..939ad9a5014
--- /dev/null
+++ b/src/interfaces/jdbc/postgresql/PGlobj.java
@@ -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());
+    }
+  }
+}
-- 
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