aaac7fed
 liuqimichale
add
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var hpack = require('../hpack');
var utils = hpack.utils;
var encoder = hpack.encoder;
var table = hpack.table;
var assert = utils.assert;
var inherits = require('inherits');
var Duplex = require('readable-stream').Duplex;
function Compressor(options) {
Duplex.call(this, {
writableObjectMode: true
});
this._encoder = null;
this._table = table.create(options.table);
}
inherits(Compressor, Duplex);
module.exports = Compressor;
Compressor.create = function create(options) {
return new Compressor(options);
};
Compressor.prototype._read = function _read() {
// We only push!
};
Compressor.prototype._write = function _write(data, enc, cb) {
assert(Array.isArray(data), 'Compressor.write() expects list of headers');
this._encoder = encoder.create();
for (var i = 0; i < data.length; i++)
this._encodeHeader(data[i]);
var data = this._encoder.render();
this._encoder = null;
cb(null);
for (var i = 0; i < data.length; i++)
this.push(data[i]);
};
Compressor.prototype.updateTableSize = function updateTableSize(size) {
if (size >= this._table.protocolMaxSize) {
size = this._table.protocolMaxSize;
var enc = encoder.create();
// indexed = 0
// incremental = 0
// update = 1
enc.encodeBits(1, 3);
enc.encodeInt(size);
var data = enc.render();
for (var i = 0; i < data.length; i++)
this.push(data[i]);
}
this._table.updateSize(size);
};
Compressor.prototype.reset = function reset() {
var enc = encoder.create();
var size = this._table.maxSize;
// indexed = 0
// incremental = 0
// update = 1
enc.encodeBits(1, 3);
enc.encodeInt(0);
// Evict everything
this._table.updateSize(0);
// indexed = 0
// incremental = 0
// update = 1
enc.encodeBits(1, 3);
enc.encodeInt(size);
// Revert size
this._table.updateSize(size);
var data = enc.render();
for (var i = 0; i < data.length; i++)
this.push(data[i]);
};
Compressor.prototype._encodeHeader = function _encodeHeader(header) {
if (header.neverIndex) {
var index = 0;
var neverIndex = 1;
var isIndexed = 0;
var isIncremental = 0;
} else {
var index = this._table.reverseLookup(header.name, header.value);
var isIndexed = index > 0;
var isIncremental = header.incremental !== false;
var neverIndex = 0;
}
this._encoder.encodeBit(isIndexed);
if (isIndexed) {
this._encoder.encodeInt(index);
return;
}
var name = utils.toArray(header.name);
var value = utils.toArray(header.value);
this._encoder.encodeBit(isIncremental);
if (isIncremental) {
this._table.add(header.name, header.value, name.length, value.length);
} else {
// Update = false
this._encoder.encodeBit(0);
this._encoder.encodeBit(neverIndex);
}
// index is negative for `name`-only headers
this._encoder.encodeInt(-index);
if (index === 0)
this._encoder.encodeStr(name, header.huffman !== false);
this._encoder.encodeStr(value, header.huffman !== false);
};
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