Expose LOB functionality as a stream

Author: cjbj

lib/oracledb.js

@@ -27,20 +27,102 @@ try {
   } else {
     throw err;
   }
-} 
+}
+
+var Duplex = require('stream').Duplex;
+var util = require('util');
+
+util.inherits(Lob, Duplex);
+
+function Lob(iLob, opt)
+{
+  Duplex.call(this, opt);
+  this.iLob = iLob;
+  this.once('finish', this.close);
+  Object.defineProperties(
+    this,
+    {
+      "chunkSize": {value: iLob.chunkSize,
+                    writable: false },
+      
+      "length": {get: function() {return iLob.length}},
+      
+      "pieceSize": {get: function() {return iLob.pieceSize;},
+                    set: function(newPieceSize) {iLob.pieceSize = newPieceSize;}},
+    });
+}
+
+Lob.prototype._read = function()
+{
+  var self = this;
+
+  self.iLob.read(
+    function(err, str)
+    {
+      if (err) {
+        self.close();
+        self.emit('error', err);
+        return;
+      }
+      if (!str) {
+        self.close();
+      }
+      self.push(str);
+    });
+}
+
+Lob.prototype._write = function(data, encoding, cb)
+{
+  var self = this;
+
+  self.iLob.write(
+    data,
+    function(err)
+    {
+      if (err) {
+        self.close();
+        return cb(err);
+      }
+      cb();
+    });
+}
+
+Lob.prototype.close = function(cb)
+{
+  var self = this;
+
+  if (cb) {
+    this.once('close', cb);
+  }
+
+  if (self.iLob != null) {
+    self.iLob.release();
+    self.iLob = null;
+  }
+  self.emit('close');
+}
+
+oracledb.Oracledb.prototype.newLob = function(iLob)
+{
+  return new Lob(iLob, null);
+}
 
 var oracledb_ins = new oracledb.Oracledb();
 
-oracledb_ins.STRING  = 2001;
-oracledb_ins.NUMBER  = 2002;
-oracledb_ins.DATE    = 2003;
-oracledb_ins.CURSOR  = 2004;
+oracledb_ins.DEFAULT    = 0;
+oracledb_ins.STRING     = 2001;
+oracledb_ins.NUMBER     = 2002;
+oracledb_ins.DATE       = 2003;
+oracledb_ins.CURSOR     = 2004;
+oracledb_ins.BUFFER     = 2005;
+oracledb_ins.CLOB       = 2006;
+oracledb_ins.BLOB       = 2007;
 
-oracledb_ins.BIND_IN     = 3001;
-oracledb_ins.BIND_INOUT  = 3002;
-oracledb_ins.BIND_OUT    = 3003;
+oracledb_ins.BIND_IN    = 3001;
+oracledb_ins.BIND_INOUT = 3002;
+oracledb_ins.BIND_OUT   = 3003;
 
-oracledb_ins.ARRAY   = 4001;
-oracledb_ins.OBJECT  = 4002;
+oracledb_ins.ARRAY      = 4001;
+oracledb_ins.OBJECT     = 4002;
 
 module.exports = oracledb_ins;