my-idlers/node_modules/hpack.js/lib/hpack/decompressor.js

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var hpack = require('../hpack');
var utils = hpack.utils;
var decoder = hpack.decoder;
var table = hpack.table;
var assert = utils.assert;
var inherits = require('inherits');
var Duplex = require('readable-stream').Duplex;
function Decompressor(options) {
Duplex.call(this, {
readableObjectMode: true
});
this._decoder = decoder.create();
this._table = table.create(options.table);
}
inherits(Decompressor, Duplex);
module.exports = Decompressor;
Decompressor.create = function create(options) {
return new Decompressor(options);
};
Decompressor.prototype._read = function _read() {
// We only push!
};
Decompressor.prototype._write = function _write(data, enc, cb) {
this._decoder.push(data);
cb(null);
};
Decompressor.prototype.execute = function execute(cb) {
while (!this._decoder.isEmpty()) {
try {
this._execute();
} catch (err) {
if (cb)
return done(err);
else
return this.emit('error', err);
}
}
if (cb)
done(null);
function done(err) {
process.nextTick(function() {
cb(err);
});
}
};
Decompressor.prototype.updateTableSize = function updateTableSize(size) {
this._table.updateSize(size);
};
Decompressor.prototype._execute = function _execute() {
var isIndexed = this._decoder.decodeBit();
if (isIndexed)
return this._processIndexed();
var isIncremental = this._decoder.decodeBit();
var neverIndex = 0;
if (!isIncremental) {
var isUpdate = this._decoder.decodeBit();
if (isUpdate)
return this._processUpdate();
neverIndex = this._decoder.decodeBit();
}
this._processLiteral(isIncremental, neverIndex);
};
Decompressor.prototype._processIndexed = function _processIndexed() {
var index = this._decoder.decodeInt();
var lookup = this._table.lookup(index);
this.push({ name: lookup.name, value: lookup.value, neverIndex: false });
};
Decompressor.prototype._processLiteral = function _processLiteral(inc, never) {
var index = this._decoder.decodeInt();
var name;
var nameSize;
// Literal header-name too
if (index === 0) {
name = this._decoder.decodeStr();
nameSize = name.length;
name = utils.stringify(name);
} else {
var lookup = this._table.lookup(index);
nameSize = lookup.nameSize;
name = lookup.name;
}
var value = this._decoder.decodeStr();
var valueSize = value.length;
value = utils.stringify(value);
if (inc)
this._table.add(name, value, nameSize, valueSize);
this.push({ name: name, value: value, neverIndex: never !== 0});
};
Decompressor.prototype._processUpdate = function _processUpdate() {
var size = this._decoder.decodeInt();
this.updateTableSize(size);
};