php-language-server/src/LanguageServer.php

<?php
declare(strict_types = 1);

namespace LanguageServer;

use LanguageServer\Protocol\{
    ServerCapabilities,
    ClientCapabilities,
    TextDocumentSyncKind,
    Message,
    MessageType,
    InitializeResult,
    SymbolInformation,
    TextDocumentIdentifier,
    CompletionOptions
};
use AdvancedJsonRpc;
use Sabre\Event\{Loop, Promise};
use function Sabre\Event\coroutine;
use Exception;
use Throwable;
use Webmozart\Glob\Iterator\GlobIterator;
use Webmozart\Glob\Glob;
use Webmozart\PathUtil\Path;
use Sabre\Uri;

class LanguageServer extends AdvancedJsonRpc\Dispatcher
{
    /**
     * Handles textDocument/* method calls
     *
     * @var Server\TextDocument
     */
    public $textDocument;

    /**
     * Handles workspace/* method calls
     *
     * @var Server\Workspace
     */
    public $workspace;

    public $telemetry;
    public $window;
    public $completionItem;
    public $codeLens;

    /**
     * ClientCapabilities
     */
    private $clientCapabilities;

    private $protocolReader;
    private $protocolWriter;
    private $client;

    /**
     * The root project path that was passed to initialize()
     *
     * @var string
     */
    private $rootPath;
    private $project;

    public function __construct(ProtocolReader $reader, ProtocolWriter $writer)
    {
        parent::__construct($this, '/');
        $this->protocolReader = $reader;
        $this->protocolReader->on('close', function () {
            $this->shutdown();
            $this->exit();
        });
        $this->protocolReader->on('message', function (Message $msg) {
            coroutine(function () use ($msg) {
                // Ignore responses, this is the handler for requests and notifications
                if (AdvancedJsonRpc\Response::isResponse($msg->body)) {
                    return;
                }
                $result = null;
                $error = null;
                try {
                    // Invoke the method handler to get a result
                    $result = yield $this->dispatch($msg->body);
                } catch (AdvancedJsonRpc\Error $e) {
                    // If a ResponseError is thrown, send it back in the Response
                    $error = $e;
                } catch (Throwable $e) {
                    // If an unexpected error occured, send back an INTERNAL_ERROR error response
                    $error = new AdvancedJsonRpc\Error(
                        $e->getMessage(),
                        AdvancedJsonRpc\ErrorCode::INTERNAL_ERROR,
                        null,
                        $e
                    );
                }
                // Only send a Response for a Request
                // Notifications do not send Responses
                if (AdvancedJsonRpc\Request::isRequest($msg->body)) {
                    if ($error !== null) {
                        $responseBody = new AdvancedJsonRpc\ErrorResponse($msg->body->id, $error);
                    } else {
                        $responseBody = new AdvancedJsonRpc\SuccessResponse($msg->body->id, $result);
                    }
                    $this->protocolWriter->write(new Message($responseBody));
                }
            })->otherwise('\\LanguageServer\\crash');
        });
        $this->protocolWriter = $writer;
        $this->client = new LanguageClient($reader, $writer);
    }

    /**
     * The initialize request is sent as the first request from the client to the server.
     *
     * @param ClientCapabilities $capabilities The capabilities provided by the client (editor)
     * @param string|null $rootPath The rootPath of the workspace. Is null if no folder is open.
     * @param int|null $processId The process Id of the parent process that started the server. Is null if the process has not been started by another process. If the parent process is not alive then the server should exit (see exit notification) its process.
     * @return InitializeResult
     */
    public function initialize(ClientCapabilities $capabilities, string $rootPath = null, int $processId = null): InitializeResult
    {
        $this->rootPath = $rootPath;
        $this->clientCapabilities = $capabilities;
        $this->project = new Project($this->client, $capabilities);
        $this->textDocument = new Server\TextDocument($this->project, $this->client);
        $this->workspace = new Server\Workspace($this->project, $this->client);

        // start building project index
        if ($rootPath !== null) {
            $this->indexProject()->otherwise('\\LanguageServer\\crash');
        }

        $serverCapabilities = new ServerCapabilities();
        // Ask the client to return always full documents (because we need to rebuild the AST from scratch)
        $serverCapabilities->textDocumentSync = TextDocumentSyncKind::FULL;
        // Support "Find all symbols"
        $serverCapabilities->documentSymbolProvider = true;
        // Support "Find all symbols in workspace"
        $serverCapabilities->workspaceSymbolProvider = true;
        // Support "Format Code"
        $serverCapabilities->documentFormattingProvider = true;
        // Support "Go to definition"
        $serverCapabilities->definitionProvider = true;
        // Support "Find all references"
        $serverCapabilities->referencesProvider = true;
        // Support "Hover"
        $serverCapabilities->hoverProvider = true;
        // Support "Completion"
        $serverCapabilities->completionProvider = new CompletionOptions;
        $serverCapabilities->completionProvider->resolveProvider = false;
        $serverCapabilities->completionProvider->triggerCharacters = ['$', '>'];

        return new InitializeResult($serverCapabilities);
    }

    /**
     * The shutdown request is sent from the client to the server. It asks the server to shut down, but to not exit
     * (otherwise the response might not be delivered correctly to the client). There is a separate exit notification that
     * asks the server to exit.
     *
     * @return void
     */
    public function shutdown()
    {
        unset($this->project);
    }

    /**
     * A notification to ask the server to exit its process.
     *
     * @return void
     */
    public function exit()
    {
        exit(0);
    }

    /**
     * Parses workspace files, one at a time.
     *
     * @return Promise <void>
     */
    private function indexProject(): Promise
    {
        return coroutine(function () {
            $textDocuments = yield $this->findPhpFiles();
            $count = count($textDocuments);

            $startTime = microtime(true);

            foreach ($textDocuments as $i => $textDocument) {
                // Give LS to the chance to handle requests while indexing
                yield timeout();
                $this->client->window->logMessage(
                    MessageType::LOG,
                    "Parsing file $i/$count: {$textDocument->uri}"
                );
                try {
                    yield $this->project->loadDocument($textDocument->uri);
                } catch (ContentTooLargeException $e) {
                    $this->client->window->logMessage(
                        MessageType::INFO,
                        "Ignoring file {$textDocument->uri} because it exceeds size limit of {$e->limit} bytes ({$e->size})"
                    );
                } catch (Exception $e) {
                    $this->client->window->logMessage(
                        MessageType::ERROR,
                        "Error parsing file {$textDocument->uri}: " . (string)$e
                    );
                }
            }

            $duration = (int)(microtime(true) - $startTime);
            $mem = (int)(memory_get_usage(true) / (1024 * 1024));
            $this->client->window->logMessage(
                MessageType::INFO,
                "All $count PHP files parsed in $duration seconds. $mem MiB allocated."
            );
        });
    }

    /**
     * Returns all PHP files in the workspace.
     * If the client does not support workspace/files, it falls back to searching the file system directly.
     *
     * @return Promise <TextDocumentIdentifier[]>
     */
    private function findPhpFiles(): Promise
    {
        return coroutine(function () {
            $textDocuments = [];
            $pattern = Path::makeAbsolute('**/*.php', $this->rootPath);
            if ($this->clientCapabilities->xfilesProvider) {
                // Use xfiles request
                foreach (yield $this->client->workspace->xfiles() as $textDocument) {
                    $path = Uri\parse($textDocument->uri)['path'];
                    if (Glob::match($path, $pattern)) {
                        $textDocuments[] = $textDocument;
                    }
                }
            } else {
                // Use the file system
                foreach (new GlobIterator($pattern) as $path) {
                    $textDocuments[] = new TextDocumentIdentifier(pathToUri($path));
                    yield timeout();
                }
            }
            return $textDocuments;
        });
    }
}