initial commit

reader.js

@@ -0,0 +1,111 @@
+var Iconv = require('iconv').Iconv;
+var Iconv_converters = {};
+function getIconv(from) {
+	var to = 'utf-8';
+	var key = from+'---'+to;
+	if(!(key in Iconv_converters)) {
+		Iconv_converters[key] = new Iconv(from, to);
+	}
+	return Iconv_converters[key];
+}
+
+
+
+
+
+
+function Reader(query,buffer) {
+	this.query = query;
+	this.buffer = buffer;
+	this.i = 0;
+}
+
+Reader.prototype = {
+	offset: function() { return this.i; },
+	skip: function(i) { this.i += i; },
+	string: function() {
+		var args = Array.prototype.slice.call(arguments);
+		var options = {};
+		if(args.length == 0) {
+			options = {};
+		} else if(args.length == 1) {
+			if(typeof args[0] == 'string') options = { delimiter: args[0] };
+			else if(typeof args[0] == 'number') options = { length: args[0] };
+			else options = args[0];
+		}
+
+		options.encoding = options.encoding || this.query.encoding;
+		if(options.encoding == 'latin1') options.encoding = 'windows-1252';
+
+		var start = this.i+0;
+		var end = start;
+		if(!('length' in options)) {
+			// terminated by the delimiter
+			var delim = options.delimiter || this.query.delimiter;
+			if(typeof delim == 'string') delim = delim.charCodeAt(0);
+			while(true) {
+				if(end >= this.buffer.length) return '';
+				if(this.buffer.readUInt8(end) == delim) break;
+				end++;
+			}
+			this.i = end+1;
+		} else {
+			end = start+options.length;
+			if(end > this.buffer.length) return '';
+			this.i = end;
+			if(options.stripnull && this.buffer.readUInt8(end-1) == 0) end--;
+		}
+
+		var out = this.buffer.slice(start, end);
+		var enc = options.encoding;
+		if(enc == 'utf8' || enc == 'ucs2' || enc == 'binary') {
+			out = out.toString(enc);
+		} else {
+			var converter = getIconv(enc);
+			out = converter.convert(out).toString();
+		}
+		return out;
+	},
+	uint: function(bytes) {
+		var r = 0;
+		if(this.i+bytes <= this.buffer.length) {
+			if(this.query.byteorder == 'be') {
+				if(bytes == 1) r = this.buffer.readUInt8(this.i);
+				else if(bytes == 2) r = this.buffer.readUInt16BE(this.i);
+				else if(bytes == 4) r = this.buffer.readUInt32BE(this.i);
+				else if(bytes == 8) r = Bignum.fromBuffer(this.buffer.slice(this.i,this.i+8),{endian:'big',size:'auto'});
+			} else {
+				if(bytes == 1) r = this.buffer.readUInt8(this.i);
+				else if(bytes == 2) r = this.buffer.readUInt16LE(this.i);
+				else if(bytes == 4) r = this.buffer.readUInt32LE(this.i);
+				else if(bytes == 8) r = Bignum.fromBuffer(this.buffer.slice(this.i,this.i+8),{endian:'little',size:'auto'});
+			}
+		}
+		this.i += bytes;
+		return r;
+	},
+	float: function() {
+		var r = 0;
+		if(this.i+4 <= this.buffer.length) {
+			if(this.query.byteorder == 'be') r = this.buffer.readFloatBE(this.i);
+			else r = this.buffer.readFloatLE(this.i);
+		}
+		this.i += 4;
+		return r;
+	},
+	pascal: function(enc) {
+		if(this.i >= this.buffer.length) return '';
+		var length = this.buffer.readUInt8(this.i);
+		this.i++;
+		return this.string({
+			encoding: enc,
+			length: length,
+			stripnull: true
+		});
+	},
+	done: function() {
+		return this.i >= this.buffer.length;
+	}
+};
+
+module.exports = Reader;