132 lines
3.7 KiB
JavaScript
132 lines
3.7 KiB
JavaScript
var util = require("util");
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var MetaDataBlock = require("./MetaDataBlock");
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var MetaDataBlockPicture = module.exports = function(isLast) {
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MetaDataBlock.call(this, isLast, 6);
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this.pictureType = 0;
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this.mimeType = "";
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this.description = "";
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this.width = 0;
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this.height = 0;
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this.bitsPerPixel = 0;
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this.colors = 0;
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this.pictureData = null;
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}
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util.inherits(MetaDataBlockPicture, MetaDataBlock);
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MetaDataBlockPicture.create = function(isLast, pictureType, mimeType, description, width, height, bitsPerPixel, colors, pictureData) {
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var mdb = new MetaDataBlockPicture(isLast);
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mdb.pictureType = pictureType;
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mdb.mimeType = mimeType;
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mdb.description = description;
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mdb.width = width;
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mdb.height = height;
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mdb.bitsPerPixel = bitsPerPixel;
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mdb.colors = colors;
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mdb.pictureData = pictureData;
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mdb.hasData = true;
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return mdb;
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}
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MetaDataBlockPicture.prototype.parse = function(buffer) {
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try {
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var pos = 0;
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this.pictureType = buffer.readUInt32BE(pos);
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pos += 4;
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var mimeTypeLength = buffer.readUInt32BE(pos);
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this.mimeType = buffer.toString("utf8", pos + 4, pos + 4 + mimeTypeLength);
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pos += 4 + mimeTypeLength;
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var descriptionLength = buffer.readUInt32BE(pos);
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this.description = buffer.toString("utf8", pos + 4, pos + 4 + descriptionLength);
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pos += 4 + descriptionLength;
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this.width = buffer.readUInt32BE(pos);
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this.height = buffer.readUInt32BE(pos + 4);
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this.bitsPerPixel = buffer.readUInt32BE(pos + 8);
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this.colors = buffer.readUInt32BE(pos + 12);
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pos += 16;
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var pictureDataLength = buffer.readUInt32BE(pos);
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this.pictureData = new Buffer(pictureDataLength);
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buffer.copy(this.pictureData, 0, pos + 4, pictureDataLength);
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this.hasData = true;
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}
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catch (e) {
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this.error = e;
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this.hasData = false;
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}
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}
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MetaDataBlockPicture.prototype.publish = function() {
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var pos = 0;
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var size = this.getSize();
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var buffer = new Buffer(4 + size);
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var header = size;
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header |= (this.type << 24);
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header |= (this.isLast ? 0x80000000 : 0);
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buffer.writeUInt32BE(header >>> 0, pos);
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pos += 4;
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buffer.writeUInt32BE(this.pictureType, pos);
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pos += 4;
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var mimeTypeLen = Buffer.byteLength(this.mimeType);
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buffer.writeUInt32BE(mimeTypeLen, pos);
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buffer.write(this.mimeType, pos + 4);
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pos += 4 + mimeTypeLen;
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var descriptionLen = Buffer.byteLength(this.description);
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buffer.writeUInt32BE(descriptionLen, pos);
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buffer.write(this.description, pos + 4);
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pos += 4 + descriptionLen;
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buffer.writeUInt32BE(this.width, pos);
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buffer.writeUInt32BE(this.height, pos + 4);
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buffer.writeUInt32BE(this.bitsPerPixel, pos + 8);
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buffer.writeUInt32BE(this.colors, pos + 12);
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pos += 16;
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buffer.writeUInt32BE(this.pictureData.length, pos);
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this.pictureData.copy(buffer, pos + 4);
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return buffer;
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}
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MetaDataBlockPicture.prototype.getSize = function() {
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var size = 4;
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size += 4 + Buffer.byteLength(this.mimeType);
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size += 4 + Buffer.byteLength(this.description);
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size += 16;
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size += 4 + this.pictureData.length;
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return size;
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}
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MetaDataBlockPicture.prototype.toString = function() {
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var str = "[MetaDataBlockPicture]";
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str += " type: " + this.type;
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str += ", isLast: " + this.isLast;
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if (this.error) {
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str += "\n ERROR: " + this.error;
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}
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if (this.hasData) {
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str += "\n pictureType: " + this.pictureType;
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str += "\n mimeType: " + this.mimeType;
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str += "\n description: " + this.description;
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str += "\n width: " + this.width;
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str += "\n height: " + this.height;
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str += "\n bitsPerPixel: " + this.bitsPerPixel;
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str += "\n colors: " + this.colors;
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str += "\n pictureData: " + (this.pictureData ? this.pictureData.length : "<null>");
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}
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return str;
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}
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