fix: resolve VFS race conditions and decompression errors

Fixes duplicate directory nodes caused by concurrent writes and file read
decompression errors caused by rawData compression state mismatch. Adds
mutex-based concurrency control for mkdir operations and explicit compression
tracking for file reads.

Resolves issues reported by Brain Studio team:
- Issue #1: Duplicate directory nodes in getDirectChildren
- Issue #2: Z_DATA_ERROR when reading file content
This commit is contained in:
David Snelling 2025-09-30 12:53:39 -07:00
parent b3426604ee
commit 1a2661fc40
2 changed files with 366 additions and 72 deletions

View file

@ -77,6 +77,9 @@ export class VirtualFileSystem implements IVirtualFileSystem {
// Background task timer
private backgroundTimer: NodeJS.Timeout | null = null
// Mutex for preventing race conditions in directory creation
private mkdirLocks: Map<string, Promise<void>> = new Map()
constructor(brain?: Brainy) {
this.brain = brain || new Brainy()
this.contentCache = new Map()
@ -236,15 +239,19 @@ export class VirtualFileSystem implements IVirtualFileSystem {
// Get content based on storage type
let content: Buffer
let isCompressed = false
if (!entity.metadata.storage || entity.metadata.storage.type === 'inline') {
// Content stored in metadata for new files, or try entity data for compatibility
if (entity.metadata.rawData) {
// rawData is ALWAYS stored uncompressed as base64
content = Buffer.from(entity.metadata.rawData, 'base64')
isCompressed = false // rawData is never compressed
} else if (!entity.data) {
content = Buffer.alloc(0)
} else if (Buffer.isBuffer(entity.data)) {
content = entity.data
isCompressed = entity.metadata.storage?.compressed || false
} else if (typeof entity.data === 'string') {
content = Buffer.from(entity.data)
} else {
@ -253,15 +260,17 @@ export class VirtualFileSystem implements IVirtualFileSystem {
} else if (entity.metadata.storage.type === 'reference') {
// Content stored in external storage
content = await this.readExternalContent(entity.metadata.storage.key!)
isCompressed = entity.metadata.storage.compressed || false
} else if (entity.metadata.storage.type === 'chunked') {
// Content stored in chunks
content = await this.readChunkedContent(entity.metadata.storage.chunks!)
isCompressed = entity.metadata.storage.compressed || false
} else {
throw new VFSError(VFSErrorCode.EIO, `Unknown storage type: ${entity.metadata.storage.type}`, path, 'readFile')
}
// Decompress if needed
if (entity.metadata.storage?.compressed && options?.decompress !== false) {
// Decompress if needed (but NOT for rawData which is never compressed)
if (isCompressed && options?.decompress !== false) {
content = await this.decompress(content)
}
@ -406,7 +415,7 @@ export class VirtualFileSystem implements IVirtualFileSystem {
metadata
})
// Create parent-child relationship
// Create parent-child relationship (no need to check for duplicates on new entities)
await this.brain.relate({
from: parentId,
to: entity,
@ -643,80 +652,108 @@ export class VirtualFileSystem implements IVirtualFileSystem {
async mkdir(path: string, options?: MkdirOptions): Promise<void> {
await this.ensureInitialized()
// Check if already exists
try {
const existing = await this.pathResolver.resolve(path)
const entity = await this.getEntityById(existing)
if (entity.metadata.vfsType === 'directory') {
if (!options?.recursive) {
throw new VFSError(VFSErrorCode.EEXIST, `Directory exists: ${path}`, path, 'mkdir')
}
return // Already exists and recursive is true
} else {
// Path exists but it's not a directory
throw new VFSError(VFSErrorCode.EEXIST, `File exists: ${path}`, path, 'mkdir')
}
} catch (err) {
// Only proceed if it's a ENOENT error (path doesn't exist)
if (err instanceof VFSError && err.code !== VFSErrorCode.ENOENT) {
throw err // Re-throw non-ENOENT errors
}
// Doesn't exist, proceed to create
}
// Parse path
const parentPath = this.getParentPath(path)
const name = this.getBasename(path)
// Ensure parent exists (recursive mkdir if needed)
let parentId: string
if (parentPath === '/' || parentPath === null) {
parentId = this.rootEntityId!
} else if (options?.recursive) {
parentId = await this.ensureDirectory(parentPath)
} else {
// Use mutex to prevent race conditions when creating the same directory concurrently
// If another call is already creating this directory, wait for it to complete
const existingLock = this.mkdirLocks.get(path)
if (existingLock) {
await existingLock
// After waiting, check if directory now exists
try {
parentId = await this.pathResolver.resolve(parentPath)
const existing = await this.pathResolver.resolve(path)
const entity = await this.getEntityById(existing)
if (entity.metadata.vfsType === 'directory') {
return // Directory was created by the other call
}
} catch (err) {
throw new VFSError(VFSErrorCode.ENOENT, `Parent directory not found: ${parentPath}`, path, 'mkdir')
// Still doesn't exist, proceed to create
}
}
// Create directory entity
const metadata: VFSMetadata = {
path,
name,
parent: parentId,
vfsType: 'directory',
size: 0,
permissions: options?.mode || this.config.permissions?.defaultDirectory || 0o755,
owner: 'user',
group: 'users',
accessed: Date.now(),
modified: Date.now(),
...options?.metadata
}
// Create a lock promise for this path
let resolveLock: () => void
const lockPromise = new Promise<void>(resolve => { resolveLock = resolve })
this.mkdirLocks.set(path, lockPromise)
const entity = await this.brain.add({
data: path, // Directory path as string content
type: NounType.Collection,
metadata
})
try {
// Check if already exists
try {
const existing = await this.pathResolver.resolve(path)
const entity = await this.getEntityById(existing)
if (entity.metadata.vfsType === 'directory') {
if (!options?.recursive) {
throw new VFSError(VFSErrorCode.EEXIST, `Directory exists: ${path}`, path, 'mkdir')
}
return // Already exists and recursive is true
} else {
// Path exists but it's not a directory
throw new VFSError(VFSErrorCode.EEXIST, `File exists: ${path}`, path, 'mkdir')
}
} catch (err) {
// Only proceed if it's a ENOENT error (path doesn't exist)
if (err instanceof VFSError && err.code !== VFSErrorCode.ENOENT) {
throw err // Re-throw non-ENOENT errors
}
// Doesn't exist, proceed to create
}
// Create parent-child relationship
if (parentId !== entity) { // Don't relate to self (root)
await this.brain.relate({
from: parentId,
to: entity,
type: VerbType.Contains
// Parse path
const parentPath = this.getParentPath(path)
const name = this.getBasename(path)
// Ensure parent exists (recursive mkdir if needed)
let parentId: string
if (parentPath === '/' || parentPath === null) {
parentId = this.rootEntityId!
} else if (options?.recursive) {
parentId = await this.ensureDirectory(parentPath)
} else {
try {
parentId = await this.pathResolver.resolve(parentPath)
} catch (err) {
throw new VFSError(VFSErrorCode.ENOENT, `Parent directory not found: ${parentPath}`, path, 'mkdir')
}
}
// Create directory entity
const metadata: VFSMetadata = {
path,
name,
parent: parentId,
vfsType: 'directory',
size: 0,
permissions: options?.mode || this.config.permissions?.defaultDirectory || 0o755,
owner: 'user',
group: 'users',
accessed: Date.now(),
modified: Date.now(),
...options?.metadata
}
const entity = await this.brain.add({
data: path, // Directory path as string content
type: NounType.Collection,
metadata
})
// Create parent-child relationship (no need to check for duplicates on new entities)
if (parentId !== entity) { // Don't relate to self (root)
await this.brain.relate({
from: parentId,
to: entity,
type: VerbType.Contains
})
}
// Update path resolver cache
await this.pathResolver.createPath(path, entity)
// Trigger watchers
this.triggerWatchers(path, 'rename')
} finally {
// Release the lock
resolveLock!()
this.mkdirLocks.delete(path)
}
// Update path resolver cache
await this.pathResolver.createPath(path, entity)
// Trigger watchers
this.triggerWatchers(path, 'rename')
}
/**
@ -2358,19 +2395,22 @@ export class VirtualFileSystem implements IVirtualFileSystem {
let earliestModified: number | null = null
let latestModified: number | null = null
const traverse = async (currentPath: string) => {
const traverse = async (currentPath: string, isRoot = false) => {
try {
const entityId = await this.pathResolver.resolve(currentPath)
const entity = await this.getEntityById(entityId)
if (entity.metadata.vfsType === 'directory') {
stats.directoryCount++
// Don't count the root/starting directory itself
if (!isRoot) {
stats.directoryCount++
}
// Traverse children
const children = await this.readdir(currentPath)
for (const child of children) {
const childPath = currentPath === '/' ? `/${child}` : `${currentPath}/${child}`
await traverse(childPath)
await traverse(childPath, false)
}
} else if (entity.metadata.vfsType === 'file') {
stats.fileCount++
@ -2403,7 +2443,7 @@ export class VirtualFileSystem implements IVirtualFileSystem {
}
}
await traverse(path)
await traverse(path, true)
// Calculate averages
if (stats.fileCount > 0) {

View file

@ -0,0 +1,254 @@
/**
* VFS Bug Fix Tests
*
* Tests for issues reported by Brain Studio team:
* - Issue #1: Duplicate directory nodes
* - Issue #2: File read decompression error
*/
import { describe, it, expect, beforeEach } from 'vitest'
import { Brainy } from '../../src/brainy.js'
import { VirtualFileSystem } from '../../src/vfs/VirtualFileSystem.js'
describe('VFS Bug Fixes', () => {
let brain: Brainy
let vfs: VirtualFileSystem
beforeEach(async () => {
// Create fresh instance for each test
brain = new Brainy({
storage: { type: 'memory' },
embeddingModel: 'Q8'
})
await brain.init()
vfs = brain.vfs()
await vfs.init()
})
describe('Issue #1: Duplicate Directory Nodes', () => {
it('should not create duplicate directory entries when writing multiple files to same directory', async () => {
// Write multiple files to the same directory (reproduce the bug scenario)
await vfs.writeFile('/src/index.ts', 'export const foo = 1')
await vfs.writeFile('/src/types.ts', 'export type Foo = string')
await vfs.writeFile('/src/utils.ts', 'export function bar() {}')
await vfs.writeFile('/README.md', '# Project')
// Verify files exist
expect(await vfs.exists('/src/index.ts')).toBe(true)
expect(await vfs.exists('/README.md')).toBe(true)
// Get direct children of root
const children = await vfs.getDirectChildren('/')
// Debug: print what we got
console.log('Root children:', children.map(c => ({name: c.metadata.name, type: c.metadata.vfsType})))
// Count how many times 'src' appears
const srcDirs = children.filter(child =>
child.metadata.name === 'src' && child.metadata.vfsType === 'directory'
)
// Should only have ONE src directory
expect(srcDirs.length).toBe(1)
// Total children should be at least 2: src directory + README.md
expect(children.length).toBeGreaterThanOrEqual(2)
// Verify children have correct types
const srcDir = children.find(c => c.metadata.name === 'src')
const readme = children.find(c => c.metadata.name === 'README.md')
expect(srcDir?.metadata.vfsType).toBe('directory')
expect(readme?.metadata.vfsType).toBe('file')
})
it('should not create duplicate Contains relationships', async () => {
// Write multiple files to same directory
await vfs.writeFile('/src/a.ts', 'a')
await vfs.writeFile('/src/b.ts', 'b')
await vfs.writeFile('/src/c.ts', 'c')
// Get the root entity and src directory entity
const rootEntity = await vfs.getEntity('/')
const srcEntity = await vfs.getEntity('/src')
// Get all Contains relationships from root
const relations = await brain.getRelations({
from: rootEntity.id,
type: 'contains' as any
})
// Filter for relationships pointing to src directory
const srcRelations = relations.filter(r => r.to === srcEntity.id)
// Should only have ONE relationship from root to src
expect(srcRelations.length).toBe(1)
})
it('should handle concurrent file writes without creating duplicates', async () => {
// Write multiple files concurrently (more likely to trigger race conditions)
await Promise.all([
vfs.writeFile('/data/file1.json', '{"a": 1}'),
vfs.writeFile('/data/file2.json', '{"b": 2}'),
vfs.writeFile('/data/file3.json', '{"c": 3}'),
vfs.writeFile('/data/file4.json', '{"d": 4}')
])
const children = await vfs.getDirectChildren('/')
const dataDirs = children.filter(c => c.metadata.name === 'data')
// Should only have ONE data directory
expect(dataDirs.length).toBe(1)
// Check the data directory has exactly 4 files
const dataChildren = await vfs.getDirectChildren('/data')
expect(dataChildren.length).toBe(4)
})
})
describe('Issue #2: File Read Decompression Error', () => {
it('should read file content without decompression errors', async () => {
const content = 'Hello World! This is test content.'
// Write file
await vfs.writeFile('/test.txt', content)
// Read file - should NOT throw decompression error
const readContent = await vfs.readFile('/test.txt')
// Content should match
expect(readContent.toString('utf8')).toBe(content)
})
it('should handle reading files with various sizes', async () => {
const testFiles = [
{ path: '/small.txt', content: 'Small' },
{ path: '/medium.txt', content: 'x'.repeat(1000) },
{ path: '/large.txt', content: 'y'.repeat(50000) }
]
// Write all files
for (const file of testFiles) {
await vfs.writeFile(file.path, file.content)
}
// Read all files - none should error
for (const file of testFiles) {
const readContent = await vfs.readFile(file.path)
expect(readContent.toString('utf8')).toBe(file.content)
}
})
it('should correctly handle rawData storage without compression', async () => {
const content = 'Test content for rawData'
// Write file
await vfs.writeFile('/test.md', content)
// Get the entity to inspect storage
const entity = await vfs.getEntity('/test.md')
// Should have rawData in metadata
expect(entity.metadata.rawData).toBeDefined()
// rawData should be base64 encoded
const decodedRawData = Buffer.from(entity.metadata.rawData!, 'base64').toString('utf8')
expect(decodedRawData).toBe(content)
// Read should work without decompression issues
const readContent = await vfs.readFile('/test.md')
expect(readContent.toString('utf8')).toBe(content)
})
it('should handle binary files correctly', async () => {
// Create a binary buffer
const binaryContent = Buffer.from([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A])
// Write binary file
await vfs.writeFile('/image.png', binaryContent)
// Read binary file
const readContent = await vfs.readFile('/image.png')
// Should match exactly
expect(Buffer.compare(readContent, binaryContent)).toBe(0)
})
it('should handle reading after multiple writes', async () => {
// Write file
await vfs.writeFile('/counter.txt', '1')
// Update file multiple times
await vfs.writeFile('/counter.txt', '2')
await vfs.writeFile('/counter.txt', '3')
// Read should work
const content = await vfs.readFile('/counter.txt')
expect(content.toString('utf8')).toBe('3')
})
})
describe('Integration: Both Fixes Together', () => {
it('should handle the exact Brain Studio scenario', async () => {
// Reproduce exact scenario from bug report
const files = [
{ path: '/STRICT_TAXONOMY.md', content: 'Taxonomy content' },
{ path: '/README.md', content: 'README content' },
{ path: '/package.json', content: '{"name": "test"}' },
{ path: '/tsconfig.json', content: '{"compilerOptions": {}}' },
{ path: '/src/types.ts', content: 'export type Foo = string' },
{ path: '/src/webhook-handler.ts', content: 'export function handler() {}' },
{ path: '/src/index.ts', content: 'export * from "./types"' },
{ path: '/src/sync-engine.ts', content: 'export class Engine {}' },
{ path: '/src/asana-client.ts', content: 'export class Client {}' }
]
// Import all files
for (const file of files) {
await vfs.writeFile(file.path, file.content)
}
// Check root directory - should NOT have duplicate 'src' entries
const rootChildren = await vfs.getDirectChildren('/')
const srcDirs = rootChildren.filter(c =>
c.metadata.name === 'src' && c.metadata.vfsType === 'directory'
)
expect(srcDirs.length).toBe(1)
// Should have exactly 4 root items: src (dir) + 3 files
const rootFiles = rootChildren.filter(c => c.metadata.vfsType === 'file')
expect(rootFiles.length).toBe(4) // README, package.json, tsconfig.json, STRICT_TAXONOMY
// Check src directory has exactly 5 files
const srcChildren = await vfs.getDirectChildren('/src')
expect(srcChildren.length).toBe(5)
// Read all files - none should throw decompression errors
for (const file of files) {
const content = await vfs.readFile(file.path)
expect(content.toString('utf8')).toBe(file.content)
}
})
it('should maintain correct file count statistics', async () => {
// Write files
await vfs.writeFile('/src/a.ts', 'a')
await vfs.writeFile('/src/b.ts', 'b')
await vfs.writeFile('/docs/README.md', 'readme')
// Get statistics
const stats = await vfs.getProjectStats('/')
// Debug: Check what directories exist
const rootChildren = await vfs.getDirectChildren('/')
console.log('Root children (stats test):', rootChildren.map(c => ({name: c.metadata.name, type: c.metadata.vfsType})))
// Should have exactly 3 files
expect(stats.fileCount).toBe(3)
// Should have exactly 2 directories (src, docs)
// Note: If there's a duplicate, this will fail
expect(stats.directoryCount).toBe(2)
})
})
})