file-entry-cache
Table of Contents
- file-entry-cache
- Features
- Table of Contents
- Installation
- Getting Started
- Changes from v10 to v11
- Changes from v9 to v10
- Global Default Functions
- FileEntryCache Options (FileEntryCacheOptions)
- API
- Get File Descriptor
- Path Security and Traversal Prevention
- Using Checksums to Determine if a File has Changed (useCheckSum)
- Setting Additional Meta Data
- Logger Support
- How to Contribute
- License and Copyright
file-entry-cache
A lightweight cache for file metadata, ideal for processes that work on a specific set of files and only need to reprocess files that have changed since the last run
Features
- Lightweight cache for file metadata
- Ideal for processes that work on a specific set of files
- Persists cache to Disk via
reconcile()orpersistIntervaloncacheoptions. - Uses
checksumto determine if a file has changed - Supports
relativeandabsolutepaths with configurable current working directory - Portable cache files when using relative paths
- ESM and CommonJS support with Typescript
Table of Contents
- Installation
- Getting Started
- Changes from v10 to v11
- Changes from v9 to v10
- Global Default Functions
- FileEntryCache Options (FileEntryCacheOptions)
- API
- Get File Descriptor
- Path Security and Traversal Prevention
- Using Checksums to Determine if a File has Changed (useCheckSum)
- Setting Additional Meta Data
- Logger Support
- How to Contribute
- License and Copyright
Installation
npm install file-entry-cache
Getting Started
import fileEntryCache from 'file-entry-cache';
const cache = fileEntryCache.create('cache1');
// Using relative paths
let fileDescriptor = cache.getFileDescriptor('./src/file.txt');
console.log(fileDescriptor.changed); // true as it is the first time
console.log(fileDescriptor.key); // './src/file.txt' (stored as provided)
fileDescriptor = cache.getFileDescriptor('./src/file.txt');
console.log(fileDescriptor.changed); // false as it has not changed
// do something to change the file
fs.writeFileSync('./src/file.txt', 'new data foo bar');
// check if the file has changed
fileDescriptor = cache.getFileDescriptor('./src/file.txt');
console.log(fileDescriptor.changed); // true
Using create() with options for more control:
import fileEntryCache from 'file-entry-cache';
// Create cache with options
const cache = fileEntryCache.create('myCache', './.cache', {
useCheckSum: true, // Use checksums for more reliable change detection
cwd: '/path/to/project', // Custom working directory
restrictAccessToCwd: false, // Allow access outside cwd (use with caution)
useAbsolutePathAsKey: false // Store relative paths in cache
});
let fileDescriptor = cache.getFileDescriptor('./src/file.txt');
console.log(fileDescriptor.changed); // true
console.log(fileDescriptor.meta.hash); // checksum hash
Save it to Disk and Reconcile files that are no longer found
import fileEntryCache from 'file-entry-cache';
const cache = fileEntryCache.create('cache1');
let fileDescriptor = cache.getFileDescriptor('./src/file.txt');
console.log(fileDescriptor.changed); // true as it is the first time
cache.reconcile(); // save the cache to disk and remove files that are no longer found
Load the cache from a file:
import fileEntryCache from 'file-entry-cache';
// Basic usage
const cache = fileEntryCache.createFromFile('/path/to/cache/file');
let fileDescriptor = cache.getFileDescriptor('./src/file.txt');
console.log(fileDescriptor.changed); // false as it has not changed from the saved cache.
// With options
const cache2 = fileEntryCache.createFromFile('/path/to/cache/file', {
useCheckSum: true,
cwd: '/path/to/project'
});
Changes from v10 to v11
BREAKING CHANGES:
-
create()andcreateFromFile()now useCreateOptionsobject - The function signatures have changed to accept an options object instead of individual parameters for better extensibility and clarity.Old API (v10):
// v10 - positional parameters const cache = fileEntryCache.create(cacheId, cacheDirectory, useCheckSum, cwd); const cache2 = fileEntryCache.createFromFile(filePath, useCheckSum, cwd);New API (v11):
// v11 - options object const cache = fileEntryCache.create(cacheId, cacheDirectory, { useCheckSum: true, cwd: '/path/to/project', restrictAccessToCwd: false }); const cache2 = fileEntryCache.createFromFile(filePath, { useCheckSum: true, cwd: '/path/to/project', restrictAccessToCwd: false }); -
Renamed
strictPathstorestrictAccessToCwd- For better clarity and self-documentation, the option that restricts file access to the current working directory has been renamed.Migration:
// Old const cache = new FileEntryCache({ strictPaths: true }); cache.strictPaths = false; // New const cache = new FileEntryCache({ restrictAccessToCwd: true }); cache.restrictAccessToCwd = false; -
Renamed
currentWorkingDirectorytocwd- For consistency with common conventions and brevity, the property has been renamed tocwd.Migration:
// Old const cache = new FileEntryCache({ currentWorkingDirectory: '/path/to/project' }); cache.currentWorkingDirectory = '/new/path'; // New const cache = new FileEntryCache({ cwd: '/path/to/project' }); cache.cwd = '/new/path';
NEW FEATURES:
- Added
cwdoption - You can now specify a custom current working directory for resolving relative paths - Added
restrictAccessToCwdoption - Provides protection against path traversal attacks (disabled by default for backwards compatibility) - Added
useAbsolutePathAsKeyoption - Whentrue, cache keys use absolute paths instead of the provided paths. Default isfalsefor better cache portability with relative paths - Added
loggeroption - Support for Pino-compatible logger instances to enable debugging and monitoring of cache operations. See Logger Support section for details - Improved cache portability - When using relative paths with the same
cwd, cache files are portable across different environments
Changes from v9 to v10
There have been many features added and changes made to the file-entry-cache class. Here are the main changes:
- Added
cacheobject to the options to allow for more control over the cache - Added
hashAlgorithmto the options to allow for different checksum algorithms. Note that if you load from file it most likely will break if the value was something before. - Migrated to Typescript with ESM and CommonJS support. This allows for better type checking and support for both ESM and CommonJS.
- Once options are passed in they get assigned as properties such as
hashAlgorithm. For the Cache options they are assigned tocachesuch ascache.ttlandcache.lruSize. - Added
cache.persistIntervalto allow for saving the cache to disk at a specific interval. This will save the cache to disk at the interval specified instead of callingreconsile()to save. (offby default) - Added
getFileDescriptorsByPath(filePath: string): FileEntryDescriptor[]to get all the file descriptors that start with the path specified. This is useful when you want to get all the files in a directory or a specific path. - Using
flat-cachev6 which is a major update. This allows for better performance and more control over the cache. - On
FileEntryDescriptor.metaif using typescript you need to use themeta.datato set additional information. This is to allow for better type checking and to avoid conflicts with themetaobject which wasany.
Global Default Functions
create(cacheId: string, cacheDirectory?: string, options?: CreateOptions)- Creates a new instance of theFileEntryCacheclasscreateFromFile(filePath: string, options?: CreateOptions)- Creates a new instance of theFileEntryCacheclass and loads the cache from a file.
CreateOptions Type
All options from FileEntryCacheOptions except cache:
useCheckSum?- Iftrueit will use a checksum to determine if the file has changed. Default isfalsehashAlgorithm?- The algorithm to use for the checksum. Default ismd5cwd?- The current working directory for resolving relative paths. Default isprocess.cwd()restrictAccessToCwd?- Iftruerestricts file access to withincwdboundaries. Default isfalseuseAbsolutePathAsKey?- Iftrueuses absolute paths as cache keys. Default isfalselogger?- A logger instance for debugging. Default isundefined
FileEntryCache Options (FileEntryCacheOptions)
useModifiedTime?- Iftrueit will use the modified time to determine if the file has changed. Default istrueuseCheckSum?- Iftrueit will use a checksum to determine if the file has changed. Default isfalsehashAlgorithm?- The algorithm to use for the checksum. Default ismd5but can be any algorithm supported bycrypto.createHashcwd?- The current working directory for resolving relative paths. Default isprocess.cwd()restrictAccessToCwd?- Iftruerestricts file access to withincwdboundaries, preventing path traversal attacks. Default istruelogger?- A logger instance compatible with Pino logger interface for debugging and monitoring. Default isundefinedcache.ttl?- The time to live for the cache in milliseconds. Default is0which means no expirationcache.lruSize?- The number of items to keep in the cache. Default is0which means no limitcache.useClone?- Iftrueit will clone the data before returning it. Default isfalsecache.expirationInterval?- The interval to check for expired items in the cache. Default is0which means no expirationcache.persistInterval?- The interval to save the data to disk. Default is0which means no persistencecache.cacheDir?- The directory to save the cache files. Default is./cachecache.cacheId?- The id of the cache. Default iscache1cache.parse?- The function to parse the data. Default isflatted.parsecache.stringify?- The function to stringify the data. Default isflatted.stringify
API
constructor(options?: FileEntryCacheOptions)- Creates a new instance of theFileEntryCacheclassuseCheckSum: boolean- Iftrueit will use a checksum to determine if the file has changed. Default isfalsehashAlgorithm: string- The algorithm to use for the checksum. Default ismd5but can be any algorithm supported bycrypto.createHashgetHash(buffer: Buffer): string- Gets the hash of a buffer used for checksumscwd: string- The current working directory for resolving relative paths. Default isprocess.cwd()restrictAccessToCwd: boolean- Iftruerestricts file access to withincwdboundaries. Default istrueuseAbsolutePathAsKey: boolean- Iftrueuses absolute paths as cache keys. Default isfalseto maintain better cache portabilitylogger: ILogger | undefined- A logger instance for debugging and monitoring cache operationscreateFileKey(filePath: string): string- Returns the cache key for the file path (returns the path exactly as provided whenuseAbsolutePathAsKeyisfalse, otherwise returns the absolute path).deleteCacheFile(): boolean- Deletes the cache file from diskdestroy(): void- Destroys the cache. This will clear the cache in memory. If using cache persistence it will stop the interval.removeEntry(filePath: string): void- Removes an entry from the cache.reconcile(): void- Saves the cache to disk and removes any files that are no longer found.hasFileChanged(filePath: string): boolean- Checks if the file has changed. This will returntrueif the file has changed.getFileDescriptor(filePath: string, options?: { useModifiedTime?: boolean, useCheckSum?: boolean }): FileEntryDescriptor- Gets the file descriptor for the file. Please refer to the entire section onGet File Descriptorfor more information.normalizeEntries(files?: string[]): FileDescriptor[]- Normalizes the entries. If no files are provided, it will return all cached entries.analyzeFiles(files: string[])will returnAnalyzedFilesobject withchangedFiles,notFoundFiles, andnotChangedFilesas FileDescriptor arrays.getUpdatedFiles(files: string[])will return an array ofFileEntryDescriptorobjects that have changed.getFileDescriptorsByPath(filePath: string): FileEntryDescriptor[]will return an array ofFileEntryDescriptorobjects that starts with the path prefix specified.getAbsolutePath(filePath: string): string- Resolves a relative path to absolute using the configuredcwd. Returns absolute paths unchanged. WhenrestrictAccessToCwdis enabled, throws an error if the path resolves outsidecwd.getAbsolutePathWithCwd(filePath: string, cwd: string): string- Resolves a relative path to absolute using a custom working directory. WhenrestrictAccessToCwdis enabled, throws an error if the path resolves outside the providedcwd.
Get File Descriptor
The getFileDescriptor(filePath: string, options?: { useCheckSum?: boolean, useModifiedTime?: boolean }): FileEntryDescriptor function is used to get the file descriptor for the file. This function will return a FileEntryDescriptor object that has the following properties:
key: string- The cache key for the file. This is exactly the path that was provided (relative or absolute).changed: boolean- If the file has changed since the last time it was analyzed.notFound: boolean- If the file was not found.meta: FileEntryMeta- The meta data for the file. This has the following properties:size,mtime,hash,data. Note thatdatais an object that can be used to store additional information.err- If there was an error analyzing the file.
Path Handling and Current Working Directory
The cache stores paths exactly as they are provided (relative or absolute). When checking if files have changed, relative paths are resolved using the configured cwd (current working directory):
// Default: uses process.cwd()
const cache1 = fileEntryCache.create('cache1');
// Custom working directory using options object
const cache2 = fileEntryCache.create('cache2', './cache', {
cwd: '/project/root'
});
// Or using the class constructor directly
const cache3 = new FileEntryCache({ cwd: '/project/root' });
// The cache key is always the provided path
const descriptor = cache2.getFileDescriptor('./src/file.txt');
console.log(descriptor.key); // './src/file.txt'
// But file operations resolve from: '/project/root/src/file.txt'
Cache Portability
Using relative paths with a consistent cwd (defaults to process.cwd()) makes cache files portable across different machines and environments. This is especially useful for CI/CD pipelines and team development.
// On machine A (project at /home/user/project)
const cacheA = fileEntryCache.create('build-cache', './cache', {
cwd: '/home/user/project'
});
cacheA.getFileDescriptor('./src/index.js'); // Resolves to /home/user/project/src/index.js
cacheA.reconcile();
// On machine B (project at /workspace/project)
const cacheB = fileEntryCache.create('build-cache', './cache', {
cwd: '/workspace/project'
});
cacheB.getFileDescriptor('./src/index.js'); // Resolves to /workspace/project/src/index.js
// Cache hit! File hasn't changed since machine A
Maximum Portability with Checksums
For maximum cache portability across different environments, use checksums (useCheckSum: true) along with relative paths and cwd which defaults to process.cwd(). This ensures that cache validity is determined by file content rather than modification times, which can vary across systems:
// Development machine
const devCache = fileEntryCache.create('.buildcache', './cache', {
useCheckSum: true // Use checksums for content-based comparison
});
// Process files using relative paths
const descriptor = devCache.getFileDescriptor('./src/index.js');
if (descriptor.changed) {
console.log('Building ./src/index.js...');
// Build process here
}
devCache.reconcile(); // Save cache
// CI/CD Pipeline or another developer's machine
const ciCache = fileEntryCache.create('.buildcache', './node_modules/.cache', {
useCheckSum: true, // Same checksum setting
cwd: process.cwd() // Different absolute path, same relative structure
});
// Same relative path works across environments
const descriptor2 = ciCache.getFileDescriptor('./src/index.js');
if (!descriptor2.changed) {
console.log('Using cached result for ./src/index.js');
// Skip rebuild - file content unchanged
}
Handling Project Relocations
Cache remains valid even when projects are moved or renamed:
// Original location: /projects/my-app
const cache1 = fileEntryCache.create('.cache', './cache', {
useCheckSum: true,
cwd: '/projects/my-app'
});
cache1.getFileDescriptor('./src/app.js');
cache1.reconcile();
// After moving project to: /archived/2024/my-app
const cache2 = fileEntryCache.create('.cache', './cache', {
useCheckSum: true,
cwd: '/archived/2024/my-app'
});
cache2.getFileDescriptor('./src/app.js'); // Still finds cached entry!
// Cache valid as long as relative structure unchanged
If there is an error when trying to get the file descriptor it will return a notFound and err property with the error.
const fileEntryCache = new FileEntryCache();
const fileDescriptor = fileEntryCache.getFileDescriptor('no-file');
if (fileDescriptor.err) {
console.error(fileDescriptor.err);
}
if (fileDescriptor.notFound) {
console.error('File not found');
}
Path Security and Traversal Prevention
The restrictAccessToCwd option provides security against path traversal attacks by restricting file access to within the configured cwd boundaries. This is enabled by default (since v11) to ensure secure defaults when processing untrusted input or when running in security-sensitive environments.
Basic Usage
// restrictAccessToCwd is enabled by default for security
const cache = new FileEntryCache({
cwd: '/project/root'
});
// This will work - file is within cwd
const descriptor = cache.getFileDescriptor('./src/index.js');
// This will throw an error - attempts to access parent directory
try {
cache.getFileDescriptor('../../../etc/passwd');
} catch (error) {
console.error(error); // Path traversal attempt blocked
}
// To allow parent directory access (not recommended for untrusted input)
const unsafeCache = new FileEntryCache({
cwd: '/project/root',
restrictAccessToCwd: false // Explicitly disable protection
});
Security Features
When restrictAccessToCwd is enabled:
- Path Traversal Prevention: Blocks attempts to access files outside the working directory using
../sequences - Null Byte Protection: Automatically removes null bytes from paths to prevent injection attacks
- Path Normalization: Cleans and normalizes paths to prevent bypass attempts
Use Cases
Build Tools with Untrusted Input
// Secure build tool configuration
const cache = fileEntryCache.create('.buildcache', './cache', {
useCheckSum: true,
cwd: process.cwd(),
restrictAccessToCwd: true // Enable strict path checking for security
});
// Process user-provided file paths safely
function processUserFile(userProvidedPath) {
try {
const descriptor = cache.getFileDescriptor(userProvidedPath);
// Safe to process - file is within boundaries
return descriptor;
} catch (error) {
if (error.message.includes('Path traversal attempt blocked')) {
console.warn('Security: Blocked access to:', userProvidedPath);
return null;
}
throw error;
}
}
CI/CD Environments
// Strict security for CI/CD pipelines
const cache = new FileEntryCache({
cwd: process.env.GITHUB_WORKSPACE || process.cwd(),
restrictAccessToCwd: true, // Prevent access outside workspace
useCheckSum: true // Content-based validation
});
// All file operations are now restricted to the workspace
cache.getFileDescriptor('./src/app.js'); // ✓ Allowed
cache.getFileDescriptor('/etc/passwd'); // ✗ Blocked (absolute path outside cwd)
cache.getFileDescriptor('../../../root'); // ✗ Blocked (path traversal)
Dynamic Security Control
const cache = new FileEntryCache({ cwd: '/safe/directory' });
// Start with relaxed mode for trusted operations
cache.restrictAccessToCwd = false;
processInternalFiles();
// Enable strict mode for untrusted input
cache.restrictAccessToCwd = true;
processUserUploadedPaths();
// Return to relaxed mode if needed
cache.restrictAccessToCwd = false;
Default Behavior
As of v11, restrictAccessToCwd is enabled by default to provide secure defaults. This means:
- Path traversal attempts using
../are blocked - File access is restricted to within the configured
cwd - Null bytes in paths are automatically sanitized
Migrating from v10 or Earlier
If you're upgrading from v10 or earlier and need to maintain the previous behavior (for example, if your code legitimately accesses parent directories), you can explicitly disable strict paths:
const cache = new FileEntryCache({
cwd: process.cwd(),
restrictAccessToCwd: false // Restore v10 behavior
});
However, we strongly recommend keeping restrictAccessToCwd: true and adjusting your code to work within the security boundaries, especially when processing any untrusted input.
Using Checksums to Determine if a File has Changed (useCheckSum)
By default the useCheckSum is false. This means that the FileEntryCache will use the mtime and ctime to determine if the file has changed. If you set useCheckSum to true it will use a checksum to determine if the file has changed. This is useful when you want to make sure that the file has not changed at all.
const fileEntryCache = new FileEntryCache();
const fileDescriptor = fileEntryCache.getFileDescriptor('file.txt', { useCheckSum: true });
You can pass useCheckSum in the FileEntryCache options, as a property .useCheckSum to make it default for all files, or in the getFileDescriptor function. Here is an example where you set it globally but then override it for a specific file:
const fileEntryCache = new FileEntryCache({ useCheckSum: true });
const fileDescriptor = fileEntryCache.getFileDescriptor('file.txt', { useCheckSum: false });
Setting Additional Meta Data
In the past we have seen people do random values on the meta object. This can cause issues with the meta object. To avoid this we have data which can be anything.
const fileEntryCache = new FileEntryCache();
const fileDescriptor = fileEntryCache.getFileDescriptor('file.txt');
fileDescriptor.meta.data = { myData: 'myData' }; //anything you want
Logger Support
The FileEntryCache supports logging through a Pino-compatible logger interface. This is useful for debugging and monitoring cache operations in production environments.
Logger Interface
The logger must implement the following interface:
interface ILogger {
level?: string;
trace: (message: string | object, ...args: unknown[]) => void;
debug: (message: string | object, ...args: unknown[]) => void;
info: (message: string | object, ...args: unknown[]) => void;
warn: (message: string | object, ...args: unknown[]) => void;
error: (message: string | object, ...args: unknown[]) => void;
fatal: (message: string | object, ...args: unknown[]) => void;
}
Using Pino Logger
You can pass a Pino logger instance to the FileEntryCache constructor or set it via the logger property:
import pino from 'pino';
import fileEntryCache from 'file-entry-cache';
// Create a Pino logger
const logger = pino({
level: 'debug',
transport: {
target: 'pino-pretty',
options: {
colorize: true
}
}
});
// Pass logger in constructor
const cache = new fileEntryCache.FileEntryCache({
logger,
cacheId: 'my-cache'
});
// Or set it after creation
cache.logger = logger;
// Now all cache operations will be logged
const descriptor = cache.getFileDescriptor('./src/file.txt');
Log Levels
The logger will output different levels of information:
- trace: Detailed internal operations (key creation, cached meta lookup, file stats)
- debug: Method entry, checksum settings, change detection, file status
- info: Important state changes (file has changed)
- error: File read errors and exceptions
Example with Custom Log Levels
import pino from 'pino';
import { FileEntryCache } from 'file-entry-cache';
// Create logger with specific level
const logger = pino({ level: 'info' });
const cache = new FileEntryCache({
logger,
useCheckSum: true
});
// This will log at info level when files change
const files = ['./src/index.js', './src/utils.js'];
files.forEach(file => {
const descriptor = cache.getFileDescriptor(file);
if (descriptor.changed) {
console.log(`Processing changed file: ${file}`);
}
});
cache.reconcile();
Debugging Cache Operations
For detailed debugging, set the logger level to debug or trace:
import pino from 'pino';
import { FileEntryCache } from 'file-entry-cache';
const logger = pino({
level: 'trace',
transport: {
target: 'pino-pretty'
}
});
const cache = new FileEntryCache({
logger,
useCheckSum: true,
cwd: '/project/root'
});
// Will log detailed information about:
// - File path resolution
// - Cache key creation
// - Cached metadata lookup
// - File stats reading
// - Hash calculation (if using checksums)
// - Change detection logic
const descriptor = cache.getFileDescriptor('./src/app.js');
How to Contribute
You can contribute by forking the repo and submitting a pull request. Please make sure to add tests and update the documentation. To learn more about how to contribute go to our main README https://github.com/jaredwray/cacheable. This will talk about how to Open a Pull Request, Ask a Question, or Post an Issue.