Skip to content

cache results of fileExists check in default compiler host #5367

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Oct 23, 2015
Merged

cache results of fileExists check in default compiler host #5367

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
6dda170
cache results of fileExists check in default compiler host
vladima Oct 22, 2015
7158a65
move 'fileExists' caching to tsc
vladima Oct 22, 2015
19a222e
addressed PR feedback
vladima Oct 23, 2015
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 18 additions & 0 deletions src/compiler/tsc.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -159,6 +159,11 @@ namespace ts {
let timerHandleForRecompilation: number; // Handle for 0.25s wait timer to trigger recompilation
let timerHandleForDirectoryChanges: number; // Handle for 0.25s wait timer to trigger directory change handler

// This map stores and reuses results of fileExists check that happen inside 'createProgram'
// This allows to save time in module resolution heavy scenarios when existence of the same file might be checked multiple times.
let cachedExistingFiles: Map<boolean>;
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

can you add a comment here to explain why this is needed.

let hostFileExists: typeof compilerHost.fileExists;

if (commandLine.options.locale) {
if (!isJSONSupported()) {
reportDiagnostic(createCompilerDiagnostic(Diagnostics.The_current_host_does_not_support_the_0_option, "--locale"));
Expand Down Expand Up @@ -274,8 +279,14 @@ namespace ts {
compilerHost = createCompilerHost(compilerOptions);
hostGetSourceFile = compilerHost.getSourceFile;
compilerHost.getSourceFile = getSourceFile;

hostFileExists = compilerHost.fileExists;
compilerHost.fileExists = cachedFileExists;
}

// reset the cache of existing files
cachedExistingFiles = {};

let compileResult = compile(rootFileNames, compilerOptions, compilerHost);

if (!compilerOptions.watch) {
Expand All @@ -286,6 +297,13 @@ namespace ts {
reportWatchDiagnostic(createCompilerDiagnostic(Diagnostics.Compilation_complete_Watching_for_file_changes));
}

function cachedFileExists(fileName: string): boolean {
if (hasProperty(cachedExistingFiles, fileName)) {
return cachedExistingFiles[fileName];
}
return cachedExistingFiles[fileName] = hostFileExists(fileName);
}

function getSourceFile(fileName: string, languageVersion: ScriptTarget, onError?: (message: string) => void) {
// Return existing SourceFile object if one is available
if (cachedProgram) {
Expand Down