tart/Tests/TartTests/VMStorageOCITests.swift

973 lines
40 KiB
Swift

import Foundation
import XCTest
@testable import tart
#if canImport(DiskImageKit)
import DiskImageKit
#endif
final class VMStorageOCITests: XCTestCase {
func testPopulateStandalonePushedImageCachesDiskAndManifest() throws {
try withTemporaryTartHome {
let source = try standaloneSource(diskData: Data("disk".utf8))
let manifest = try flatManifest()
let name = try digestName(for: manifest)
let storage = try VMStorageOCI()
try storage.populate(name, from: source, manifest: manifest)
let cached = try storage.open(name)
XCTAssertTrue(cached.isStandalone)
XCTAssertEqual(try Data(contentsOf: cached.diskURL), Data("disk".utf8))
XCTAssertEqual(try OCIManifest(fromJSON: Data(contentsOf: cached.manifestURL)), manifest)
}
}
func testStackedCloneRequiresManifestForLegacyStandaloneCachedImage() throws {
try withTemporaryTartHome {
let manifest = try flatManifest()
let name = try digestName(for: manifest)
let storage = try VMStorageOCI()
let record = try storage.create(name)
try config().save(toURL: record.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: record.nvramURL.path, contents: Data()))
XCTAssertTrue(FileManager.default.createFile(atPath: record.diskURL.path, contents: Data()))
XCTAssertTrue(try storage.hasUsableCachedImageForClone(name))
XCTAssertFalse(try storage.hasUsableCachedImageForClone(name, requireManifest: true))
}
}
func testCloneCacheCheckRejectsMissingOrWrongSizedStackedContent() throws {
try withTemporaryTartHome {
let baseData = Data("base".utf8)
let overlayData = Data("overlay".utf8)
let baseDigest = Digest.hash(baseData)
let overlayDigest = Digest.hash(overlayData)
let manifest = try stackedManifest(
baseContentDigest: baseDigest,
overlayContentDigest: overlayDigest,
baseUncompressedSize: UInt64(baseData.count),
overlayUncompressedSize: UInt64(overlayData.count)
)
let name = try digestName(for: manifest)
let storage = try VMStorageOCI()
let record = try storage.create(name)
try config().save(toURL: record.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: record.nvramURL.path, contents: Data()))
try manifest.toJSON().write(to: record.manifestURL)
XCTAssertFalse(try storage.hasUsableCachedImageForClone(name))
let contentStore = try ContentStore()
try installContent(baseData, contentDigest: baseDigest, into: contentStore)
try installContent(overlayData, contentDigest: overlayDigest, into: contentStore)
XCTAssertTrue(try storage.hasUsableCachedImageForClone(name))
try Data("bad".utf8).write(to: try contentStore.contentURL(for: overlayDigest))
XCTAssertFalse(try storage.hasUsableCachedImageForClone(name))
}
}
func testListIncludesStackedCachedImage() throws {
try withTemporaryTartHome {
let manifest = try stackedManifest()
let name = try digestName(for: manifest)
let storage = try VMStorageOCI()
let record = try storage.create(name)
try config().save(toURL: record.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: record.nvramURL.path, contents: Data()))
try manifest.toJSON().write(to: record.manifestURL)
XCTAssertTrue(try storage.list().contains { $0.0 == name.description })
XCTAssertEqual(try record.diskSizeBytes(), 4096)
XCTAssertNoThrow(try record.allocatedSizeBytes())
}
}
func testStackedCacheHitRequiresExpectedContentSizes() throws {
try withTemporaryTartHome {
let baseData = Data(repeating: 0x41, count: 10)
let overlayData = Data(repeating: 0x42, count: 20)
let baseDigest = Digest.hash(baseData)
let overlayDigest = Digest.hash(overlayData)
let manifest = try stackedManifest(
baseContentDigest: baseDigest,
overlayContentDigest: overlayDigest,
baseUncompressedSize: 10,
overlayUncompressedSize: 20
)
let name = try digestName(for: manifest)
let storage = try VMStorageOCI()
let record = try storage.create(name)
try config().save(toURL: record.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: record.nvramURL.path, contents: Data()))
try manifest.toJSON().write(to: record.manifestURL)
XCTAssertFalse(try storage.hasCompleteCachedImage(name, manifest: manifest))
XCTAssertEqual(try storage.requiredDiskStorageBytes(for: manifest), 30)
let contentStore = try ContentStore()
try installContent(baseData, contentDigest: baseDigest, into: contentStore)
XCTAssertFalse(try storage.hasCompleteCachedImage(name, manifest: manifest))
XCTAssertEqual(try storage.requiredDiskStorageBytes(for: manifest), 20)
try installContent(overlayData, contentDigest: overlayDigest, into: contentStore)
XCTAssertTrue(try storage.hasCompleteCachedImage(name, manifest: manifest))
XCTAssertEqual(try storage.requiredDiskStorageBytes(for: manifest), 0)
let overlayURL = try contentStore.contentURL(for: overlayDigest)
try Data("corrupt".utf8).write(to: overlayURL)
XCTAssertFalse(try storage.hasCompleteCachedImage(name, manifest: manifest))
XCTAssertEqual(try storage.requiredDiskStorageBytes(for: manifest), 20)
}
}
func testStackedPullReusesPreviouslyPulledStandaloneDisk() throws {
try withTemporaryTartHome {
let diskData = Data([0])
let contentDigest = Digest.hash(diskData)
let flatManifest = try flatManifest()
let flatName = try digestName(for: flatManifest)
let storage = try VMStorageOCI()
let flatRecord = try storage.create(flatName)
try config().save(toURL: flatRecord.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: flatRecord.nvramURL.path, contents: Data()))
try diskData.write(to: flatRecord.diskURL)
try flatManifest.toJSON().write(to: flatRecord.manifestURL)
let stackedManifest = try stackedManifest(baseContentDigest: contentDigest)
XCTAssertNil(try ContentStore().existingContentURL(for: contentDigest))
try storage.reuseStandaloneDiskForStackedBaseIfPossible(stackedManifest)
let reusedURL = try XCTUnwrap(try ContentStore().existingContentURL(for: contentDigest))
XCTAssertEqual(try Data(contentsOf: reusedURL), diskData)
}
}
func testStackedPullDoesNotRehashInstalledBaseBeforeReuse() throws {
try withTemporaryTartHome {
let contentDigest = Digest.hash(Data("base".utf8))
let manifest = try stackedManifest(baseContentDigest: contentDigest)
let contentURL = try ContentStore().contentURL(for: contentDigest)
// Hashing this path would throw. Once an entry is published, this
// fast path must trust its presence and let normal pull validation
// repair unusable content later.
try FileManager.default.createDirectory(at: contentURL, withIntermediateDirectories: false)
XCTAssertNoThrow(try VMStorageOCI().reuseStandaloneDiskForStackedBaseIfPossible(manifest))
}
}
func testNewTagDoesNotValidateCachedStackBeforeLock() throws {
try withTemporaryTartHome {
let baseDigest = Digest.hash(Data("base".utf8))
let overlayDigest = Digest.hash(Data("overlay".utf8))
let manifest = try stackedManifest(
baseContentDigest: baseDigest,
overlayContentDigest: overlayDigest
)
let digestName = try digestName(for: manifest)
let tagName = RemoteName(
host: digestName.host,
namespace: digestName.namespace,
reference: Reference(tag: "latest")
)
let storage = try VMStorageOCI()
let record = try storage.create(digestName)
try config().save(toURL: record.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: record.nvramURL.path, contents: Data()))
try manifest.toJSON().write(to: record.manifestURL)
// Hashing this directory as a disk file throws. A new tag must skip
// validation until after it has taken the host lock.
let contentURL = try ContentStore().contentURL(for: baseDigest)
try FileManager.default.createDirectory(at: contentURL, withIntermediateDirectories: false)
XCTAssertFalse(try storage.hasCompleteLinkedImage(tagName, digestName: digestName, manifest: manifest))
}
}
func testStandaloneLayerCacheIgnoresStackedCachedImages() async throws {
try await withTemporaryTartHome {
var targetManifest = try flatManifest()
var stackedCandidateManifest = try stackedManifest()
let sharedDiskSize = 2 * 1024 * 1024 * 1024
targetManifest.layers[1].size = sharedDiskSize
stackedCandidateManifest.layers[1] = targetManifest.layers[1]
let candidateName = try digestName(for: stackedCandidateManifest)
let storage = try VMStorageOCI()
let candidate = try storage.create(candidateName)
try config().save(toURL: candidate.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: candidate.nvramURL.path, contents: Data()))
try stackedCandidateManifest.toJSON().write(to: candidate.manifestURL)
let targetName = RemoteName(
host: "example.com",
namespace: "org/target",
reference: Reference(digest: try targetManifest.digest())
)
let registry = try Registry(host: targetName.host, namespace: targetName.namespace)
let layerCache = try await storage.chooseLocalLayerCache(targetName, targetManifest, registry)
XCTAssertNil(layerCache)
}
}
func testGCPrunesOnlyUnreferencedContent() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let referenced = try installContent(Data("referenced".utf8), into: contentStore)
let unreferenced = try installContent(Data("unreferenced".utf8), into: contentStore)
let stacked = try VMStorageLocal().create("stacked")
try config().save(toURL: stacked.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: stacked.nvramURL.path, contents: Data()))
XCTAssertTrue(FileManager.default.createFile(atPath: stacked.overlayURL.path, contents: Data()))
try pinnedBaseManifest(contentDigest: referenced.digest).toJSON().write(to: stacked.manifestURL)
try VMStorageOCI().gc()
XCTAssertTrue(FileManager.default.fileExists(atPath: referenced.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: unreferenced.url.path))
}
}
func testGCPrunesContentWithoutOCIStorageDirectory() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let unreferenced = try installContent(Data("unreferenced".utf8), into: contentStore)
let storage = try VMStorageOCI()
XCTAssertFalse(FileManager.default.fileExists(atPath: storage.baseURL.path))
try storage.gc()
XCTAssertFalse(FileManager.default.fileExists(atPath: unreferenced.url.path))
}
}
func testGCDoesNotPruneContentReferencedByInProgressManifest() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let referenced = try installContent(Data("in-progress".utf8), into: contentStore)
let temporaryVMDir = try VMDirectory.temporary()
// Pull and clone publish the manifest before config, NVRAM, or a
// writable overlay necessarily exist.
try pinnedBaseManifest(contentDigest: referenced.digest).toJSON().write(to: temporaryVMDir.manifestURL)
try VMStorageOCI().gc()
XCTAssertTrue(FileManager.default.fileExists(atPath: referenced.url.path))
}
}
func testStalePrunableDoesNotDeleteNewlyReferencedContent() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let content = try installContent(Data("new-reference".utf8), into: contentStore)
let storage = try VMStorageOCI()
let candidate = try XCTUnwrap(storage.prunables().first {
$0.url.resolvingSymlinksInPath() == content.url.resolvingSymlinksInPath()
})
// Simulate a clone or pull publishing its manifest after prune built
// the candidate list but before deletion starts.
let temporaryVMDir = try VMDirectory.temporary()
try contentStore.withPruneLock {
try pinnedBaseManifest(contentDigest: content.digest).toJSON().write(to: temporaryVMDir.manifestURL)
}
try candidate.delete()
XCTAssertTrue(FileManager.default.fileExists(atPath: content.url.path))
}
}
func testVMDirectoryDeletionOfStackedOCIRecordWaitsForPruneLock() throws {
try withTemporaryTartHome {
let storage = try VMStorageOCI()
let record = try createRecord(for: stackedManifest(), in: storage)
try assertDeletionWaitsForPruneLock(record: record) {
try record.delete()
}
}
}
func testStorageDeletionOfStackedOCIRecordWaitsForPruneLock() throws {
try withTemporaryTartHome {
let storage = try VMStorageOCI()
let manifest = try stackedManifest()
let name = try digestName(for: manifest)
let record = try createRecord(for: manifest, in: storage)
try assertDeletionWaitsForPruneLock(record: record) {
try storage.delete(name)
}
}
}
func testStorageDeletionOfIncompleteManifestRecordWaitsForPruneLock() throws {
try withTemporaryTartHome {
let storage = try VMStorageOCI()
let name = RemoteName(
host: "example.com",
namespace: "org/image",
reference: Reference(digest: "sha256:incomplete")
)
let record = try storage.create(name)
try Data("{}".utf8).write(to: record.manifestURL)
try assertDeletionWaitsForPruneLock(record: record) {
try storage.delete(name)
}
}
}
func testVMDirectoryDeletionOfUnpublishedRecordWaitsForPruneLock() throws {
try withTemporaryTartHome {
let storage = try VMStorageOCI()
let record = try storage.create(RemoteName(
host: "example.com",
namespace: "org/image",
reference: Reference(digest: "sha256:unpublished")
))
try assertDeletionWaitsForPruneLock(record: record) {
try record.removeFromDisk()
}
}
}
func testTagReplacementWaitsForPruneLock() throws {
try withTemporaryTartHome {
let storage = try VMStorageOCI()
let firstManifest = try stackedManifest(baseContentDigest: "sha256:first")
let secondManifest = try stackedManifest(baseContentDigest: "sha256:second")
let firstName = try digestName(for: firstManifest)
let secondName = try digestName(for: secondManifest)
_ = try createRecord(for: firstManifest, in: storage)
_ = try createRecord(for: secondManifest, in: storage)
let tagName = RemoteName(
host: secondName.host,
namespace: secondName.namespace,
reference: Reference(tag: "latest")
)
let contentStore = try ContentStore()
let lockHeld = DispatchSemaphore(value: 0)
let releaseLock = DispatchSemaphore(value: 0)
let replacementStarted = DispatchSemaphore(value: 0)
let replacementFinished = DispatchSemaphore(value: 0)
DispatchQueue.global().async {
try? contentStore.withPruneLock {
lockHeld.signal()
releaseLock.wait()
}
}
XCTAssertEqual(lockHeld.wait(timeout: .now() + 1), .success)
DispatchQueue.global().async {
replacementStarted.signal()
try? storage.link(from: tagName, to: secondName)
replacementFinished.signal()
}
XCTAssertEqual(replacementStarted.wait(timeout: .now() + 1), .success)
XCTAssertEqual(replacementFinished.wait(timeout: .now() + 0.1), .timedOut)
releaseLock.signal()
XCTAssertEqual(replacementFinished.wait(timeout: .now() + 1), .success)
XCTAssertTrue(storage.linked(from: tagName, to: secondName))
XCTAssertFalse(storage.linked(from: tagName, to: firstName))
}
}
func testGCDeletionOfStackedOCIRecordWaitsForPruneLock() throws {
try withTemporaryTartHome {
let storage = try VMStorageOCI()
let record = try createRecord(for: stackedManifest(), in: storage)
try assertDeletionWaitsForPruneLock(record: record) {
try storage.gc()
}
}
}
func testTemporaryManifestGCWaitsForPruneLock() throws {
try withTemporaryTartHome {
let temporaryVMDir = try VMDirectory.temporary()
try stackedManifest().toJSON().write(to: temporaryVMDir.manifestURL)
try assertDeletionWaitsForPruneLock(record: temporaryVMDir) {
try Config().gc()
}
}
}
func testLockedTemporaryDirectorySurvivesGarbageCollection() throws {
try withTemporaryTartHome {
let temporaryVMDir = try VMDirectory.temporary()
let lock = try FileLock(lockURL: temporaryVMDir.baseURL)
try lock.lock()
try Config().gc()
XCTAssertTrue(FileManager.default.fileExists(atPath: temporaryVMDir.baseURL.path))
try lock.unlock()
try Config().gc()
XCTAssertFalse(FileManager.default.fileExists(atPath: temporaryVMDir.baseURL.path))
}
}
func testMovingStackedOCIRecordWaitsForPruneLock() throws {
try withTemporaryTartHome {
let storage = try VMStorageOCI()
let source = try temporaryVMDirectory()
let manifest = try stackedManifest()
let name = try digestName(for: manifest)
try config().save(toURL: source.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: source.nvramURL.path, contents: Data()))
try manifest.toJSON().write(to: source.manifestURL)
let contentStore = try ContentStore()
let lockHeld = DispatchSemaphore(value: 0)
let releaseLock = DispatchSemaphore(value: 0)
let moveStarted = DispatchSemaphore(value: 0)
let moveFinished = DispatchSemaphore(value: 0)
DispatchQueue.global().async {
try? contentStore.withPruneLock {
lockHeld.signal()
releaseLock.wait()
}
}
XCTAssertEqual(lockHeld.wait(timeout: .now() + 1), .success)
DispatchQueue.global().async {
moveStarted.signal()
try? storage.move(name, from: source)
moveFinished.signal()
}
XCTAssertEqual(moveStarted.wait(timeout: .now() + 1), .success)
XCTAssertEqual(moveFinished.wait(timeout: .now() + 0.1), .timedOut)
XCTAssertTrue(FileManager.default.fileExists(atPath: source.baseURL.path))
releaseLock.signal()
XCTAssertEqual(moveFinished.wait(timeout: .now() + 1), .success)
XCTAssertFalse(FileManager.default.fileExists(atPath: source.baseURL.path))
XCTAssertTrue(try storage.open(name).isStackedCachedImage)
}
}
func testPruningLastStackedOCIRecordReclaimsItsContent() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let baseContent = try installContent(Data("record-only-base".utf8), into: contentStore)
let overlayContent = try installContent(Data("record-only-overlay".utf8), into: contentStore)
let manifest = try stackedManifest(
baseContentDigest: baseContent.digest,
overlayContentDigest: overlayContent.digest,
baseUncompressedSize: UInt64(try baseContent.url.sizeBytes()),
overlayUncompressedSize: UInt64(try overlayContent.url.sizeBytes())
)
let name = try digestName(for: manifest)
let storage = try VMStorageOCI()
let record = try storage.create(name)
try config().save(toURL: record.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: record.nvramURL.path, contents: Data()))
try manifest.toJSON().write(to: record.manifestURL)
let candidate = try XCTUnwrap(storage.prunables().first {
$0.url.lastPathComponent == record.url.lastPathComponent
})
XCTAssertGreaterThanOrEqual(
try candidate.allocatedSizeBytes(),
try baseContent.url.allocatedSizeBytes() + overlayContent.url.allocatedSizeBytes()
)
// The record itself fits in this budget, so pruning only succeeds if it
// accounts for the immutable content released with the final reference.
try Prune.pruneSpaceBudget(
prunableStorages: [storage],
spaceBudgetBytes: UInt64(try record.allocatedSizeBytes())
)
XCTAssertFalse(FileManager.default.fileExists(atPath: record.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: baseContent.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: overlayContent.url.path))
}
}
func testMalformedStackedOCIRecordDoesNotBlockPruning() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let baseContent = try installContent(Data("valid-base".utf8), into: contentStore)
let overlayContent = try installContent(Data("valid-overlay".utf8), into: contentStore)
let storage = try VMStorageOCI()
let validRecord = try createRecord(for: stackedManifest(
baseContentDigest: baseContent.digest,
overlayContentDigest: overlayContent.digest,
baseUncompressedSize: UInt64(try baseContent.url.sizeBytes()),
overlayUncompressedSize: UInt64(try overlayContent.url.sizeBytes())
), in: storage)
let malformedRecord = try storage.create(RemoteName(
host: "example.com",
namespace: "org/image",
reference: Reference(digest: "sha256:malformed")
))
try config().save(toURL: malformedRecord.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: malformedRecord.nvramURL.path, contents: Data()))
try Data("{".utf8).write(to: malformedRecord.manifestURL)
XCTAssertNoThrow(try storage.prunables())
try Prune.pruneSpaceBudget(prunableStorages: [storage], spaceBudgetBytes: 0)
XCTAssertFalse(FileManager.default.fileExists(atPath: validRecord.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: malformedRecord.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: baseContent.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: overlayContent.url.path))
}
}
func testPruningOneStackedOCIRecordPreservesSharedContent() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let baseContent = try installContent(Data("shared-base".utf8), into: contentStore)
let firstOverlay = try installContent(Data("first-overlay".utf8), into: contentStore)
let secondOverlay = try installContent(Data("second-overlay".utf8), into: contentStore)
let storage = try VMStorageOCI()
let firstManifest = try stackedManifest(
baseContentDigest: baseContent.digest,
overlayContentDigest: firstOverlay.digest,
baseUncompressedSize: UInt64(try baseContent.url.sizeBytes()),
overlayUncompressedSize: UInt64(try firstOverlay.url.sizeBytes())
)
let secondManifest = try stackedManifest(
baseContentDigest: baseContent.digest,
overlayContentDigest: secondOverlay.digest,
baseUncompressedSize: UInt64(try baseContent.url.sizeBytes()),
overlayUncompressedSize: UInt64(try secondOverlay.url.sizeBytes())
)
let firstRecord = try createRecord(for: firstManifest, in: storage)
let secondRecord = try createRecord(for: secondManifest, in: storage)
let firstCandidate = try XCTUnwrap(storage.prunables().first {
$0.url.lastPathComponent == firstRecord.url.lastPathComponent
})
try firstCandidate.delete()
XCTAssertTrue(FileManager.default.fileExists(atPath: baseContent.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: firstOverlay.url.path))
XCTAssertTrue(FileManager.default.fileExists(atPath: secondOverlay.url.path))
let secondCandidate = try XCTUnwrap(storage.prunables().first {
$0.url.lastPathComponent == secondRecord.url.lastPathComponent
})
try secondCandidate.delete()
XCTAssertFalse(FileManager.default.fileExists(atPath: baseContent.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: secondOverlay.url.path))
}
}
func testSpaceBudgetRecomputesSharedContentAfterOwnerDeletion() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let baseContent = try installContent(Data("shared-base".utf8), into: contentStore)
let firstOverlay = try installContent(Data("first-overlay".utf8), into: contentStore)
let secondOverlay = try installContent(Data("second-overlay".utf8), into: contentStore)
let storage = try VMStorageOCI()
let firstManifest = try stackedManifest(
baseContentDigest: baseContent.digest,
overlayContentDigest: firstOverlay.digest,
baseUncompressedSize: UInt64(try baseContent.url.sizeBytes()),
overlayUncompressedSize: UInt64(try firstOverlay.url.sizeBytes())
)
let secondManifest = try stackedManifest(
baseContentDigest: baseContent.digest,
overlayContentDigest: secondOverlay.digest,
baseUncompressedSize: UInt64(try baseContent.url.sizeBytes()),
overlayUncompressedSize: UInt64(try secondOverlay.url.sizeBytes())
)
let olderRecord = try createRecord(for: firstManifest, in: storage)
let newerRecord = try createRecord(for: secondManifest, in: storage)
try olderRecord.url.updateAccessDate(Date(timeIntervalSince1970: 1))
try newerRecord.url.updateAccessDate(Date(timeIntervalSince1970: 2))
let olderCandidate = try XCTUnwrap(storage.prunables().first {
$0.url.lastPathComponent == olderRecord.url.lastPathComponent
})
let budget = UInt64(try olderCandidate.allocatedSizeBytes())
// On the first pass the newer record owns the shared base and is
// selected for deletion, while the older record fits this budget.
// Recomputing must then charge the surviving record for the base and
// prune it too.
try Prune.pruneSpaceBudget(
prunableStorages: [storage],
spaceBudgetBytes: budget
)
XCTAssertFalse(FileManager.default.fileExists(atPath: olderRecord.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: newerRecord.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: baseContent.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: firstOverlay.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: secondOverlay.url.path))
}
}
func testSpaceBudgetRecomputesBeforeDeletingAnotherCandidate() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let sharedBase = try installContent(Data(repeating: 0x41, count: 128 * 1024), into: contentStore)
let newestOverlay = try installContent(Data("newest-overlay".utf8), into: contentStore)
let middleOverlay = try installContent(Data("middle-overlay".utf8), into: contentStore)
let retainedBase = try installContent(Data(repeating: 0x42, count: 32 * 1024), into: contentStore)
let retainedOverlay = try installContent(Data("retained-overlay".utf8), into: contentStore)
let storage = try VMStorageOCI()
let newest = try createRecord(for: stackedManifest(
baseContentDigest: sharedBase.digest,
overlayContentDigest: newestOverlay.digest,
baseUncompressedSize: UInt64(try sharedBase.url.sizeBytes()),
overlayUncompressedSize: UInt64(try newestOverlay.url.sizeBytes())
), in: storage)
let middle = try createRecord(for: stackedManifest(
baseContentDigest: sharedBase.digest,
overlayContentDigest: middleOverlay.digest,
baseUncompressedSize: UInt64(try sharedBase.url.sizeBytes()),
overlayUncompressedSize: UInt64(try middleOverlay.url.sizeBytes())
), in: storage)
let retained = try createRecord(for: stackedManifest(
baseContentDigest: retainedBase.digest,
overlayContentDigest: retainedOverlay.digest,
baseUncompressedSize: UInt64(try retainedBase.url.sizeBytes()),
overlayUncompressedSize: UInt64(try retainedOverlay.url.sizeBytes())
), in: storage)
try newest.url.updateAccessDate(Date(timeIntervalSince1970: 3))
try middle.url.updateAccessDate(Date(timeIntervalSince1970: 2))
try retained.url.updateAccessDate(Date(timeIntervalSince1970: 1))
let retainedCandidate = try XCTUnwrap(storage.prunables().first {
$0.url.lastPathComponent == retained.url.lastPathComponent
})
// Initially the newest record owns the shared base and is too large.
// The middle record appears small enough to retain, making the oldest
// unrelated record look like a second deletion candidate. After the
// first deletion, ownership moves to the middle record; recomputing
// before selecting again must delete it and preserve the unrelated one.
try Prune.pruneSpaceBudget(
prunableStorages: [storage],
spaceBudgetBytes: UInt64(try retainedCandidate.allocatedSizeBytes())
)
XCTAssertFalse(FileManager.default.fileExists(atPath: newest.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: middle.url.path))
XCTAssertTrue(FileManager.default.fileExists(atPath: retained.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: sharedBase.url.path))
XCTAssertTrue(FileManager.default.fileExists(atPath: retainedBase.url.path))
XCTAssertTrue(FileManager.default.fileExists(atPath: retainedOverlay.url.path))
}
}
func testAutomaticReclaimRecomputesSharedContentAfterOwnerDeletion() throws {
try withTemporaryTartHome {
let contentStore = try ContentStore()
let sharedBase = try installContent(Data(repeating: 0x41, count: 128 * 1024), into: contentStore)
let initiatorOverlay = try installContent(Data("initiator-overlay".utf8), into: contentStore)
let ownerOverlay = try installContent(Data("owner-overlay".utf8), into: contentStore)
let unrelatedBase = try installContent(Data("unrelated-base".utf8), into: contentStore)
let unrelatedOverlay = try installContent(Data("unrelated-overlay".utf8), into: contentStore)
let storage = try VMStorageOCI()
let initiatorManifest = try stackedManifest(
baseContentDigest: sharedBase.digest,
overlayContentDigest: initiatorOverlay.digest,
baseUncompressedSize: UInt64(try sharedBase.url.sizeBytes()),
overlayUncompressedSize: UInt64(try initiatorOverlay.url.sizeBytes())
)
let ownerManifest = try stackedManifest(
baseContentDigest: sharedBase.digest,
overlayContentDigest: ownerOverlay.digest,
baseUncompressedSize: UInt64(try sharedBase.url.sizeBytes()),
overlayUncompressedSize: UInt64(try ownerOverlay.url.sizeBytes())
)
let unrelatedManifest = try stackedManifest(
baseContentDigest: unrelatedBase.digest,
overlayContentDigest: unrelatedOverlay.digest,
baseUncompressedSize: UInt64(try unrelatedBase.url.sizeBytes()),
overlayUncompressedSize: UInt64(try unrelatedOverlay.url.sizeBytes())
)
let initiator = try createRecord(for: initiatorManifest, in: storage)
let owner = try createRecord(for: ownerManifest, in: storage)
let unrelated = try createRecord(for: unrelatedManifest, in: storage)
try initiator.url.updateAccessDate(Date(timeIntervalSince1970: 1))
try owner.url.updateAccessDate(Date(timeIntervalSince1970: 2))
try unrelated.url.updateAccessDate(Date(timeIntervalSince1970: 3))
let sharedBaseSize = UInt64(try sharedBase.url.allocatedSizeBytes())
// The owner is the first deletable record and is initially charged for
// the shared base. Deleting it cannot reclaim that base because the
// protected initiator still references it, so reclaim must continue.
try Prune.reclaimIfPossible(sharedBaseSize, initiator)
XCTAssertTrue(FileManager.default.fileExists(atPath: initiator.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: owner.url.path))
XCTAssertFalse(FileManager.default.fileExists(atPath: unrelated.url.path))
XCTAssertTrue(FileManager.default.fileExists(atPath: sharedBase.url.path))
}
}
#if canImport(DiskImageKit)
@available(macOS 27.0, *)
func testPopulateStackedPushedImageCachesImmutableTopOverlay() throws {
if #unavailable(macOS 27.0) {
throw XCTSkip("DiskImageKit tests require macOS 27 or newer")
}
try withTemporaryTartHome {
let source = try diskImageSource()
let stacked = try temporaryVMDirectory()
try source.cloneAsStackedBase(to: stacked, generateMAC: false)
var manifest = try OCIManifest(fromJSON: Data(contentsOf: stacked.manifestURL))
let contentDigest = try Digest.hash(stacked.overlayURL)
var overlay = OCIManifestLayer(
mediaType: asifOverlayMediaType,
size: 1,
digest: "sha256:overlay-transport",
uncompressedSize: 1,
uncompressedContentDigest: "sha256:overlay-chunk"
)
overlay.annotations?[diskFileContentDigestAnnotation] = contentDigest
overlay.annotations?[diskFileChunkCountAnnotation] = "1"
manifest.layers.insert(overlay, at: manifest.layers.count - 1)
let name = try digestName(for: manifest)
let storage = try VMStorageOCI()
try storage.populate(name, from: stacked, manifest: manifest)
let cached = try storage.open(name)
XCTAssertTrue(cached.isStackedCachedImage)
XCTAssertFalse(FileManager.default.fileExists(atPath: cached.overlayURL.path))
XCTAssertEqual(try OCIManifest(fromJSON: Data(contentsOf: cached.manifestURL)), manifest)
let cachedContent = try XCTUnwrap(try ContentStore().existingContentURL(for: contentDigest))
XCTAssertEqual(try Digest.hash(cachedContent), contentDigest)
}
}
#endif
private func standaloneSource(diskData: Data) throws -> VMDirectory {
let vmDir = try temporaryVMDirectory()
try config().save(toURL: vmDir.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: vmDir.nvramURL.path, contents: Data()))
try diskData.write(to: vmDir.diskURL)
return vmDir
}
private func createRecord(for manifest: OCIManifest, in storage: VMStorageOCI) throws -> VMDirectory {
let record = try storage.create(try digestName(for: manifest))
try config().save(toURL: record.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: record.nvramURL.path, contents: Data()))
try manifest.toJSON().write(to: record.manifestURL)
return record
}
private func assertDeletionWaitsForPruneLock(
record: VMDirectory,
deletion: @escaping () throws -> Void
) throws {
let contentStore = try ContentStore()
let lockHeld = DispatchSemaphore(value: 0)
let releaseLock = DispatchSemaphore(value: 0)
let deletionStarted = DispatchSemaphore(value: 0)
let deletionFinished = DispatchSemaphore(value: 0)
DispatchQueue.global().async {
try? contentStore.withPruneLock {
lockHeld.signal()
releaseLock.wait()
}
}
XCTAssertEqual(lockHeld.wait(timeout: .now() + 1), .success)
DispatchQueue.global().async {
deletionStarted.signal()
try? deletion()
deletionFinished.signal()
}
XCTAssertEqual(deletionStarted.wait(timeout: .now() + 1), .success)
XCTAssertEqual(deletionFinished.wait(timeout: .now() + 0.1), .timedOut)
XCTAssertTrue(FileManager.default.fileExists(atPath: record.baseURL.path))
releaseLock.signal()
XCTAssertEqual(deletionFinished.wait(timeout: .now() + 1), .success)
XCTAssertFalse(FileManager.default.fileExists(atPath: record.baseURL.path))
}
#if canImport(DiskImageKit)
@available(macOS 27.0, *)
private func diskImageSource() throws -> VMDirectory {
let vmDir = try temporaryVMDirectory()
try config().save(toURL: vmDir.configURL)
XCTAssertTrue(FileManager.default.createFile(atPath: vmDir.nvramURL.path, contents: Data()))
_ = try DiskImage(creating: .raw(url: vmDir.diskURL, blockCount: 8))
try flatManifest().toJSON().write(to: vmDir.manifestURL)
return vmDir
}
#endif
private func config() -> VMConfig {
VMConfig(
platform: Linux(),
cpuCountMin: 2,
memorySizeMin: 512 * 1024 * 1024,
diskFormat: .raw
)
}
private func flatManifest() throws -> OCIManifest {
let disk = OCIManifestLayer(
mediaType: diskV2MediaType,
size: 1,
digest: "sha256:disk-transport",
uncompressedSize: 1,
uncompressedContentDigest: "sha256:disk-chunk"
)
return OCIManifest(
config: OCIManifestConfig(size: 1, digest: "sha256:oci-config"),
layers: [
OCIManifestLayer(mediaType: configMediaType, size: 1, digest: "sha256:config"),
disk,
OCIManifestLayer(mediaType: nvramMediaType, size: 1, digest: "sha256:nvram"),
]
)
}
private func stackedManifest(
baseContentDigest: String = "sha256:base",
overlayContentDigest: String = "sha256:overlay",
baseUncompressedSize: UInt64 = 1,
overlayUncompressedSize: UInt64 = 1
) throws -> OCIManifest {
var manifest = try flatManifest()
manifest.annotations?[diskBlockSizeAnnotation] = "512"
manifest.annotations?[uncompressedDiskSizeAnnotation] = "4096"
manifest.layers[1].annotations?[diskFileContentDigestAnnotation] = baseContentDigest
manifest.layers[1].annotations?[uncompressedSizeAnnotation] = String(baseUncompressedSize)
var overlay = OCIManifestLayer(
mediaType: asifOverlayMediaType,
size: 1,
digest: "sha256:overlay-transport",
uncompressedSize: overlayUncompressedSize,
uncompressedContentDigest: "sha256:overlay-chunk"
)
overlay.annotations?[diskFileContentDigestAnnotation] = overlayContentDigest
overlay.annotations?[diskFileChunkCountAnnotation] = "1"
manifest.layers.insert(overlay, at: manifest.layers.count - 1)
return manifest
}
private func installContent(_ data: Data, contentDigest: String, into contentStore: ContentStore) throws {
let temporaryURL = try contentStore.temporaryContentURL(for: contentDigest)
try data.write(to: temporaryURL)
_ = try contentStore.install(temporaryURL, contentDigest: contentDigest)
}
private func pinnedBaseManifest(contentDigest: String) -> OCIManifest {
var disk = OCIManifestLayer(
mediaType: diskV2MediaType,
size: 1,
digest: "sha256:disk-transport",
uncompressedSize: 1,
uncompressedContentDigest: "sha256:disk-chunk"
)
disk.annotations?[diskFileContentDigestAnnotation] = contentDigest
return OCIManifest(
config: OCIManifestConfig(size: 1, digest: "sha256:oci-config"),
layers: [
OCIManifestLayer(mediaType: configMediaType, size: 1, digest: "sha256:config"),
disk,
OCIManifestLayer(mediaType: nvramMediaType, size: 1, digest: "sha256:nvram"),
]
)
}
private func installContent(_ data: Data, into contentStore: ContentStore) throws -> (digest: String, url: URL) {
let digest = Digest.hash(data)
let temporaryURL = try contentStore.temporaryContentURL(for: digest)
try data.write(to: temporaryURL)
return (digest, try contentStore.install(temporaryURL, contentDigest: digest))
}
private func digestName(for manifest: OCIManifest) throws -> RemoteName {
RemoteName(
host: "example.com",
namespace: "org/image",
reference: Reference(digest: try manifest.digest())
)
}
private func withTemporaryTartHome(_ body: () throws -> Void) throws {
let home = try temporaryDirectory()
let previousHome = ProcessInfo.processInfo.environment["TART_HOME"]
setenv("TART_HOME", home.path, 1)
defer {
if let previousHome {
setenv("TART_HOME", previousHome, 1)
} else {
unsetenv("TART_HOME")
}
}
try body()
}
private func withTemporaryTartHome(_ body: () async throws -> Void) async throws {
let home = try temporaryDirectory()
let previousHome = ProcessInfo.processInfo.environment["TART_HOME"]
setenv("TART_HOME", home.path, 1)
defer {
if let previousHome {
setenv("TART_HOME", previousHome, 1)
} else {
unsetenv("TART_HOME")
}
}
try await body()
}
private func temporaryVMDirectory() throws -> VMDirectory {
VMDirectory(baseURL: try temporaryDirectory())
}
private func temporaryDirectory() throws -> URL {
let url = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
try FileManager.default.createDirectory(at: url, withIntermediateDirectories: false)
addTeardownBlock {
try? FileManager.default.removeItem(at: url)
}
return url
}
}