Differential D20980 Diff 49996 src/channel/PhutilJSONProtocolChannel.php

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src/channel/PhutilJSONProtocolChannel.php

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				<?php

				/**
				* Channel that transmits dictionaries of primitives using JSON serialization.
				* This channel is not binary safe.
				*
				* This protocol is implemented by the Phabricator Aphlict realtime notification
				* server.
				*
				* @task protocol Protocol Implementation
				*/
				final class PhutilJSONProtocolChannel extends PhutilProtocolChannel {

				const MODE_LENGTH = 'length';
				const MODE_OBJECT = 'object';

				/**
				* Size of the "length" frame of the protocol in bytes.
				*/
				const SIZE_LENGTH = 8;

				private $mode = self::MODE_LENGTH;
				private $byteLengthOfNextChunk = self::SIZE_LENGTH;
				private $buf = '';


				/* -( Protocol Implementation )-------------------------------------------- */


				/**
				* Encode a message for transmission over the channel. The message should
				* be any serializable as JSON.
				*
				* Objects are transmitted as:
				*
				* <len><json>
				*
				* ...where <len> is an 8-character, zero-padded integer written as a string.
				* For example, this is a valid message:
				*
				* 00000015{"key":"value"}
				*
				* @task protocol
				*/
				protected function encodeMessage($message) {
				$message = json_encode($message);
				$len = sprintf(
				'%0'.self::SIZE_LENGTH.'.'.self::SIZE_LENGTH.'d',
				strlen($message));
				return "{$len}{$message}";
				}


				/**
				* Decode a message received from the other end of the channel. Messages are
				* decoded as associative arrays.
				*
				* @task protocol
				*/
				protected function decodeStream($data) {
				$this->buf .= $data;

				$objects = array();
				while (strlen($this->buf) >= $this->byteLengthOfNextChunk) {
				switch ($this->mode) {
				case self::MODE_LENGTH:
				$len = substr($this->buf, 0, self::SIZE_LENGTH);
				$this->buf = substr($this->buf, self::SIZE_LENGTH);

				$this->mode = self::MODE_OBJECT;
				$this->byteLengthOfNextChunk = (int)$len;
				break;
				case self::MODE_OBJECT:
				$data = substr($this->buf, 0, $this->byteLengthOfNextChunk);
				$this->buf = substr($this->buf, $this->byteLengthOfNextChunk);

				try {
				$objects[] = phutil_json_decode($data);
				} catch (PhutilJSONParserException $ex) {
				throw new PhutilProxyException(
				pht('Failed to decode JSON object.'),
				$ex);
				}

				$this->mode = self::MODE_LENGTH;
				$this->byteLengthOfNextChunk = self::SIZE_LENGTH;
				break;
				}
				}

				return $objects;
				}

				}