Differential D15954 Diff 38414 src/applications/diffusion/protocol/DiffusionGitWireProtocol.php

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src/applications/diffusion/protocol/DiffusionGitWireProtocol.php

This file was added.

				<?php

				final class DiffusionGitWireProtocol extends Phobject {

				private $buffer = '';
				private $state = 'head';
				private $expectBytes;
				private $expectPacks;

				private $packType;
				private $packSize;
				private $packShift;

				public function writeData($data) {
				$this->buffer .= $data;

				while (true) {
				if ($this->state == 'head') {
				if (strlen($this->buffer) < 4) {
				break;
				}

				$head = substr($this->buffer, 0, 4);
				$this->buffer = substr($this->buffer, 4);

				if ($head == 'PACK') {
				$this->state = 'pack-version';
				continue;
				}

				if (!preg_match('/^[a-f0-9]{4}\z/', $head)) {
				throw new Exception(
				pht(
				'Expected Git wire protocol frame length header (four hex '.
				'characters, like "02af") but got "%s".',
				$head));
				}

				$bytes = hexdec($head);

				// NOTE: This header is documented as containing the length of the
				// "rest of the line", but in practice it appears to include its own
				// length.
				if ($bytes >= 4) {
				$this->expectBytes = ($bytes - 4);
				} else if (!$bytes) {
				$this->expectBytes = $bytes;
				} else {
				throw new Exception(
				pht(
				'Expected Git wire protocol frame length header with valid '.
				'value (0, or >= 4 bytes) but got invalid value ("%s").',
				$bytes));
				}

				$this->state = 'body';
				} else if ($this->state == 'body') {
				if (strlen($this->buffer) < $this->expectBytes) {
				break;
				}

				$body = substr($this->buffer, 0, $this->expectBytes);
				$this->buffer = substr($this->buffer, $this->expectBytes);

				$this->state = 'head';
				} else if ($this->state == 'pack-version') {
				if (strlen($this->buffer) < 4) {
				break;
				}

				$version = substr($this->buffer, 0, 4);
				$this->buffer = substr($this->buffer, 4);

				$expect = "\x00\x00\x00\x02";
				if ($version !== $expect) {
				throw new Exception(
				pht(
				'Expected Git wire protocol packfile version 2 (four binary '.
				'bytes, "%s") but got "%s".',
				bin2hex($expect),
				bin2hex($version)));
				}

				$this->state = 'pack-length';
				} else if ($this->state == 'pack-length') {
				if (strlen($this->buffer) < 4) {
				break;
				}

				$length = substr($this->buffer, 0, 4);
				$this->buffer = substr($this->buffer, 4);

				$value = head(unpack('N', $length));
				if (!$value) {
				throw new Exception(
				pht(
				'Expected Git wire protocol pack count (four binary '.
				'bytes) but got "%s".',
				bin2hex($length)));
				}

				$this->expectPacks = $value;
				$this->state = 'pack-head';
				} else if ($this->state == 'pack-head') {
				if (!$this->expectPacks) {
				$this->state = 'pack-tail';
				continue;
				}

				if (!strlen($this->buffer)) {
				break;
				}

				$this->expectPacks--;

				$byte = substr($this->buffer, 0, 1);
				$this->buffer = substr($this->buffer, 1);

				$byte = ord($byte);
				$this->packType = ($byte >> 4) & 7;
				$this->packSize = ($byte & 15);
				$this->packShift = 4;

				if ($byte & 0x80) {
				$this->state = 'pack-head-more';
				} else {
				$this->state = 'pack-body';
				}
				} else if ($this->state == 'pack-head-more') {
				if (!strlen($this->buffer)) {
				break;
				}

				$byte = substr($this->buffer, 0, 1);
				$this->buffer = substr($this->buffer, 1);

				$byte = ord($byte);

				$this->packSize += ($byte & 0x7F) << $this->packShift;
				$this->packShift += 7;

				if ($byte & 0x80) {
				$this->state = 'pack-head-more';
				} else {
				$this->state = 'pack-body';
				}
				} else if ($this->state == 'pack-body') {
				$available = strlen($this->buffer);
				$expect = $this->packSize;

				$read_bytes = min($available, $expect);
				if ($read_bytes) {
				$pack_data = substr($this->buffer, 0, $read_bytes);
				$this->buffer = substr($this->buffer, $read_bytes);
				$this->packSize -= $read_bytes;
				}

				if (!$this->expectBytes) {
				$this->state = 'pack-head';
				}
				} else if ($this->state == 'pack-tail') {
				if (strlen($this->buffer) < 20) {
				break;
				}

				$sha1 = substr($this->buffer, 0, 20);
				$this->buffer = substr($this->buffer, 20);

				$this->state = 'head';
				}
				}

				return $data;
				}

				}