Add a record-based file IO library.

exec/load/recordfile.js

+/* TODO: File Locking */
+
+function GetRecordLength(RecordDef)
+{
+	var i;
+	var len=0;
+
+	for(i=0; i<RecordDef.length; i++) {
+		switch(RecordDef[i].type) {
+			case "Integer":
+				len+=4;
+				break;
+			case "Date":
+				len+=8;
+				break;
+			case "Boolean":
+				len+=1;
+				break;
+			default:
+				var m=RecordDef[i].type.match(/^.*:([0-9]+)$/);
+				if(m!=null)
+					len+=parseInt(m[1]);
+				break;
+		}
+	}
+	return(len);
+}
+
+function RecordFile(filename, definition)
+{
+	this.file=new File(filename);
+	if(!this.file.open(file_exists(this.file.name)?"rb+":"wb+"))
+		return(null);
+	this.fields=definition;
+	this.RecordLength=GetRecordLength(this.fields);
+	this.length=this.file.length/this.RecordLength;
+
+	/* Read a record by index */
+	this.Get=RecordFile_Get;
+	/* Create a new record */
+	this.New=RecordFile_New;
+}
+
+function RecordFile_Get(num)
+{
+	var rec=0;
+	var i;
+	var ret=new Object();
+
+	if(num==undefined || num < 0 || parseInt(num)!=num)
+		return(null);
+	num=parseInt(num);
+
+	if(num>=this.length)
+		return(null);
+
+	ret.parent=this;
+	ret.Put=RecordFileRecord_Put;
+	ret.ReLoad=RecordFileRecord_ReLoad;
+	ret.ReInit=RecordFileRecord_ReInit;
+
+	ret.Record=num;
+
+	this.file.position=ret.Record * this.RecordLength;
+	for(i=0; i<this.fields.length; i++) {
+		switch(this.fields[i].type) {
+			case "Integer":
+				ret[this.fields[i].prop]=this.file.readBin(4);
+				break;
+			case "Date":
+				ret[this.fields[i].prop]=this.file.read(8);
+				ret[this.fields[i].prop].replace(/\x00/g,"");
+				break;
+			case "Boolean":
+				var b=this.file.readBin(1);
+				if(b)
+					ret[this.fields[i].prop]=true;
+				else
+					ret[this.fields[i].prop]=false;
+				break;
+			default:
+				var m=this.fields[i].type.match(/^String:([0-9]+)$/);
+				if(m!=null) {
+					ret[this.fields[i].prop]=this.file.read(parseInt(m[1]));
+					ret[this.fields[i].prop].replace(/\x00/g,"");
+				}
+				break;
+		}
+	}
+
+	return(ret);
+}
+
+function RecordFile_New()
+{
+	var i;
+	var ret=new Object();
+
+	for(i=0; i<this.fields.length; i++)
+		ret[this.fields[i].prop]=this.fields[i].def;
+
+	ret.parent=this;
+	ret.Put=RecordFileRecord_Put;
+	ret.ReLoad=RecordFileRecord_ReLoad;
+	ret.ReInit=RecordFileRecord_ReInit;
+	ret.Record=this.length;
+	this.length++;
+	ret.Put();
+	return(ret);
+}
+
+function RecordFileRecord_ReInit()
+{
+	for(i=0; i<this.parent.fields.length; i++)
+		this[this.parent.fields[i].prop]=this.parent.fields[i].def;
+}
+
+function RecordFileRecord_Put()
+{
+	this.parent.file.position=(this.Record)*this.parent.RecordLength;
+	for(i=0; i<this.parent.fields.length; i++) {
+writeln("Saving "+this.parent.fields[i].prop+" = "+this[this.parent.fields[i].prop]);
+		switch(this.parent.fields[i].type) {
+			case "Integer":
+				this.parent.file.writeBin(this[this.parent.fields[i].prop],4);
+				break;
+			case "Date":
+				var wr=this[this.parent.fields[i].prop].substr(0,8);
+				while(wr.length < 8)
+					wr=wr+"\x00";
+				this.parent.file.write(this[this.parent.fields[i].prop],8);
+				break;
+			case "Boolean":
+				if(this[this.parent.fields[i].prop])
+					this.parent.file.writeBin(255,1);
+				else
+					this.parent.file.writeBin(0,1);
+				break;
+			default:
+				var m=this.parent.fields[i].type.match(/^String:([0-9]+)$/);
+				if(m!=null) {
+					var len=parseInt(m[1]);
+					var wr=this[this.parent.fields[i].prop].substr(0,len);
+						while(wr.length < len)
+						wr=wr+"\x00";
+					this.parent.file.write(this[this.parent.fields[i].prop],len);
+				}
+				break;
+		}
+	}
+}
+
+function RecordFileRecord_ReLoad(num)
+{
+	this.parent.file.position=(this.Record)*this.parent.RecordLength;
+	for(i=0; i<this.parent.fields.length; i++) {
+		switch(this.parent.fields[i].type) {
+			case "Integer":
+				this[this.parent.fields[i].prop]=this.parent.file.readBin(4);
+				break;
+			case "Date":
+				this[this.parent.fields[i].prop]=this.parent.file.read(8);
+				this[this.parent.fields[i].prop].replace(/\x00/g,"");
+				break;
+			case "Boolean":
+				var b=this.parent.file.readBin(1);
+				if(b)
+					this[this.parent.fields[i].prop]=true;
+				else
+					this[this.parent.fields[i].prop]=false;
+				break;
+			default:
+				var m=this.parent.fields[i].type.match(/^String:([0-9]+)$/);
+				if(m!=null) {
+					this[this.parent.fields[i].prop]=this.parent.file.read(parseInt(m[1]));
+					this[this.parent.fields[i].prop].replace(/\x00/g,"");
+				}
+				break;
+		}
+	}
+
+	return(ret);
+}