Centralized file access management

This commit is contained in:
Ali 2022-09-09 21:35:46 +04:00
parent e61ae3c0b3
commit 14bfa1ef60
2 changed files with 429 additions and 197 deletions

View File

@ -140,6 +140,7 @@ public final class MediaBox {
private let statusQueue = Queue()
private let concurrentQueue = Queue.concurrentDefaultQueue()
private let dataQueue = Queue()
private let dataFileManager: MediaBoxFileManager
private let cacheQueue = Queue()
private let timeBasedCleanup: TimeBasedCleanup
@ -194,6 +195,8 @@ public final class MediaBox {
self.basePath + "/short-cache"
])
self.dataFileManager = MediaBoxFileManager(queue: self.dataQueue)
let _ = self.ensureDirectoryCreated
}
@ -540,7 +543,7 @@ public final class MediaBox {
paths.partial,
paths.partial + ".meta"
])
if let fileContext = MediaBoxFileContext(queue: self.dataQueue, path: paths.complete, partialPath: paths.partial, metaPath: paths.partial + ".meta") {
if let fileContext = MediaBoxFileContext(queue: self.dataQueue, manager: self.dataFileManager, path: paths.complete, partialPath: paths.partial, metaPath: paths.partial + ".meta") {
context = fileContext
self.fileContexts[resourceId] = fileContext
} else {
@ -633,7 +636,7 @@ public final class MediaBox {
subscriber.putCompletion()
return EmptyDisposable
} else {
if let data = MediaBoxPartialFile.extractPartialData(path: paths.partial, metaPath: paths.partial + ".meta", range: range) {
if let data = MediaBoxPartialFile.extractPartialData(manager: MediaBoxFileManager(queue: nil), path: paths.partial, metaPath: paths.partial + ".meta", range: range) {
subscriber.putNext((data, true))
subscriber.putCompletion()
return EmptyDisposable

View File

@ -4,7 +4,180 @@ import Crc32
import ManagedFile
import RangeSet
final class MediaBoxFileManager {
enum Mode {
case read
case readwrite
}
enum AccessError: Error {
case generic
}
final class Item {
final class Accessor {
private let file: ManagedFile
init(file: ManagedFile) {
self.file = file
}
func write(_ data: UnsafeRawPointer, count: Int) -> Int {
return self.file.write(data, count: count)
}
func read(_ data: UnsafeMutableRawPointer, _ count: Int) -> Int {
return self.file.read(data, count)
}
func readData(count: Int) -> Data {
return self.file.readData(count: count)
}
func seek(position: Int64) {
self.file.seek(position: position)
}
}
weak var manager: MediaBoxFileManager?
let path: String
let mode: Mode
weak var context: ItemContext?
init(manager: MediaBoxFileManager, path: String, mode: Mode) {
self.manager = manager
self.path = path
self.mode = mode
}
deinit {
if let manager = self.manager, let context = self.context {
manager.discardItemContext(context: context)
}
}
func access(_ f: (Accessor) throws -> Void) throws {
if let context = self.context {
try f(Accessor(file: context.file))
} else {
if let manager = self.manager {
if let context = manager.takeContext(path: self.path, mode: self.mode) {
self.context = context
try f(Accessor(file: context.file))
} else {
throw AccessError.generic
}
} else {
throw AccessError.generic
}
}
}
func sync() {
if let context = self.context {
context.sync()
}
}
}
final class ItemContext {
let id: Int
let path: String
let mode: Mode
let file: ManagedFile
private var isDisposed: Bool = false
init?(id: Int, path: String, mode: Mode) {
let mappedMode: ManagedFile.Mode
switch mode {
case .read:
mappedMode = .read
case .readwrite:
mappedMode = .readwrite
}
guard let file = ManagedFile(queue: nil, path: path, mode: mappedMode) else {
return nil
}
self.file = file
self.id = id
self.path = path
self.mode = mode
}
deinit {
assert(self.isDisposed)
}
func dispose() {
if !self.isDisposed {
self.isDisposed = true
self.file._unsafeClose()
} else {
assertionFailure()
}
}
func sync() {
self.file.sync()
}
}
private let queue: Queue?
private var contexts: [Int: ItemContext] = [:]
private var nextItemId: Int = 0
private let maxOpenFiles: Int
init(queue: Queue?) {
self.queue = queue
self.maxOpenFiles = 16
}
func open(path: String, mode: Mode) -> Item? {
if let queue = self.queue {
assert(queue.isCurrent())
}
return Item(manager: self, path: path, mode: mode)
}
private func takeContext(path: String, mode: Mode) -> ItemContext? {
if let queue = self.queue {
assert(queue.isCurrent())
}
if self.contexts.count > self.maxOpenFiles {
if let minKey = self.contexts.keys.min(), let context = self.contexts[minKey] {
self.discardItemContext(context: context)
}
}
let id = self.nextItemId
self.nextItemId += 1
let context = ItemContext(id: id, path: path, mode: mode)
self.contexts[id] = context
return context
}
private func discardItemContext(context: ItemContext) {
if let queue = self.queue {
assert(queue.isCurrent())
}
if let context = self.contexts.removeValue(forKey: context.id) {
context.dispose()
}
}
}
private final class MediaBoxFileMap {
enum FileMapError: Error {
case generic
}
fileprivate(set) var sum: Int64
private(set) var ranges: RangeSet<Int64>
private(set) var truncationSize: Int64?
@ -17,173 +190,216 @@ private final class MediaBoxFileMap {
self.progress = nil
}
init?(fd: ManagedFile) {
guard let length = fd.getSize() else {
return nil
}
var firstUInt32: UInt32 = 0
guard fd.read(&firstUInt32, 4) == 4 else {
return nil
}
if firstUInt32 == 0x7bac1487 {
var crc: UInt32 = 0
guard fd.read(&crc, 4) == 4 else {
return nil
}
var count: Int32 = 0
var sum: Int64 = 0
var ranges = RangeSet<Int64>()
guard fd.read(&count, 4) == 4 else {
return nil
}
if count < 0 {
return nil
}
if count < 0 || length < 4 + 4 + 4 + 8 + count * 2 * 8 {
return nil
}
var truncationSizeValue: Int64 = 0
var data = Data(count: Int(8 + count * 2 * 8))
let dataCount = data.count
if !(data.withUnsafeMutableBytes { rawBytes -> Bool in
let bytes = rawBytes.baseAddress!.assumingMemoryBound(to: UInt8.self)
guard fd.read(bytes, dataCount) == dataCount else {
return false
}
memcpy(&truncationSizeValue, bytes, 8)
let calculatedCrc = Crc32(bytes, Int32(dataCount))
if calculatedCrc != crc {
return false
}
var offset = 8
for _ in 0 ..< count {
var intervalOffset: Int64 = 0
var intervalLength: Int64 = 0
memcpy(&intervalOffset, bytes.advanced(by: offset), 8)
memcpy(&intervalLength, bytes.advanced(by: offset + 8), 8)
offset += 8 * 2
ranges.insert(contentsOf: intervalOffset ..< (intervalOffset + intervalLength))
sum += intervalLength
}
return true
}) {
return nil
}
self.sum = sum
self.ranges = ranges
if truncationSizeValue == -1 {
self.truncationSize = nil
} else if truncationSizeValue < 0 {
self.truncationSize = nil
} else {
self.truncationSize = truncationSizeValue
}
} else {
let crc: UInt32 = firstUInt32
var count: Int32 = 0
var sum: Int32 = 0
var ranges = RangeSet<Int64>()
guard fd.read(&count, 4) == 4 else {
return nil
}
if count < 0 {
return nil
}
if count < 0 || UInt64(length) < 4 + 4 + UInt64(count) * 2 * 4 {
return nil
}
var truncationSizeValue: Int32 = 0
var data = Data(count: Int(4 + count * 2 * 4))
let dataCount = data.count
if !(data.withUnsafeMutableBytes { rawBytes -> Bool in
let bytes = rawBytes.baseAddress!.assumingMemoryBound(to: UInt8.self)
guard fd.read(bytes, dataCount) == dataCount else {
return false
}
memcpy(&truncationSizeValue, bytes, 4)
let calculatedCrc = Crc32(bytes, Int32(dataCount))
if calculatedCrc != crc {
return false
}
var offset = 4
for _ in 0 ..< count {
var intervalOffset: Int32 = 0
var intervalLength: Int32 = 0
memcpy(&intervalOffset, bytes.advanced(by: offset), 4)
memcpy(&intervalLength, bytes.advanced(by: offset + 4), 4)
offset += 8
ranges.insert(contentsOf: Int64(intervalOffset) ..< Int64(intervalOffset + intervalLength))
sum += intervalLength
}
return true
}) {
return nil
}
self.sum = Int64(sum)
self.ranges = ranges
if truncationSizeValue == -1 {
self.truncationSize = nil
} else {
self.truncationSize = Int64(truncationSizeValue)
}
}
private init(
sum: Int64,
ranges: RangeSet<Int64>,
truncationSize: Int64?,
progress: Float?
) {
self.sum = sum
self.ranges = ranges
self.truncationSize = truncationSize
self.progress = progress
}
func serialize(to file: ManagedFile) {
file.seek(position: 0)
let buffer = WriteBuffer()
var magic: UInt32 = 0x7bac1487
buffer.write(&magic, offset: 0, length: 4)
var zero: Int32 = 0
buffer.write(&zero, offset: 0, length: 4)
let rangeView = self.ranges.ranges
var count: Int32 = Int32(rangeView.count)
buffer.write(&count, offset: 0, length: 4)
var truncationSizeValue: Int64 = self.truncationSize ?? -1
buffer.write(&truncationSizeValue, offset: 0, length: 8)
for range in rangeView {
var intervalOffset = range.lowerBound
var intervalLength = range.upperBound - range.lowerBound
buffer.write(&intervalOffset, offset: 0, length: 8)
buffer.write(&intervalLength, offset: 0, length: 8)
static func read(manager: MediaBoxFileManager, path: String) throws -> MediaBoxFileMap {
guard let length = fileSize(path) else {
throw FileMapError.generic
}
guard let fileItem = manager.open(path: path, mode: .readwrite) else {
throw FileMapError.generic
}
var result: MediaBoxFileMap?
try fileItem.access { fd in
var firstUInt32: UInt32 = 0
guard fd.read(&firstUInt32, 4) == 4 else {
throw FileMapError.generic
}
if firstUInt32 == 0x7bac1487 {
var crc: UInt32 = 0
guard fd.read(&crc, 4) == 4 else {
throw FileMapError.generic
}
var count: Int32 = 0
var sum: Int64 = 0
var ranges = RangeSet<Int64>()
guard fd.read(&count, 4) == 4 else {
throw FileMapError.generic
}
if count < 0 {
throw FileMapError.generic
}
if count < 0 || length < 4 + 4 + 4 + 8 + count * 2 * 8 {
throw FileMapError.generic
}
var truncationSizeValue: Int64 = 0
var data = Data(count: Int(8 + count * 2 * 8))
let dataCount = data.count
if !(data.withUnsafeMutableBytes { rawBytes -> Bool in
let bytes = rawBytes.baseAddress!.assumingMemoryBound(to: UInt8.self)
guard fd.read(bytes, dataCount) == dataCount else {
return false
}
memcpy(&truncationSizeValue, bytes, 8)
let calculatedCrc = Crc32(bytes, Int32(dataCount))
if calculatedCrc != crc {
return false
}
var offset = 8
for _ in 0 ..< count {
var intervalOffset: Int64 = 0
var intervalLength: Int64 = 0
memcpy(&intervalOffset, bytes.advanced(by: offset), 8)
memcpy(&intervalLength, bytes.advanced(by: offset + 8), 8)
offset += 8 * 2
ranges.insert(contentsOf: intervalOffset ..< (intervalOffset + intervalLength))
sum += intervalLength
}
return true
}) {
throw FileMapError.generic
}
let mappedTruncationSize: Int64?
if truncationSizeValue == -1 {
mappedTruncationSize = nil
} else if truncationSizeValue < 0 {
mappedTruncationSize = nil
} else {
mappedTruncationSize = truncationSizeValue
}
result = MediaBoxFileMap(
sum: sum,
ranges: ranges,
truncationSize: mappedTruncationSize,
progress: nil
)
} else {
let crc: UInt32 = firstUInt32
var count: Int32 = 0
var sum: Int32 = 0
var ranges = RangeSet<Int64>()
guard fd.read(&count, 4) == 4 else {
throw FileMapError.generic
}
if count < 0 {
throw FileMapError.generic
}
if count < 0 || UInt64(length) < 4 + 4 + UInt64(count) * 2 * 4 {
throw FileMapError.generic
}
var truncationSizeValue: Int32 = 0
var data = Data(count: Int(4 + count * 2 * 4))
let dataCount = data.count
if !(data.withUnsafeMutableBytes { rawBytes -> Bool in
let bytes = rawBytes.baseAddress!.assumingMemoryBound(to: UInt8.self)
guard fd.read(bytes, dataCount) == dataCount else {
return false
}
memcpy(&truncationSizeValue, bytes, 4)
let calculatedCrc = Crc32(bytes, Int32(dataCount))
if calculatedCrc != crc {
return false
}
var offset = 4
for _ in 0 ..< count {
var intervalOffset: Int32 = 0
var intervalLength: Int32 = 0
memcpy(&intervalOffset, bytes.advanced(by: offset), 4)
memcpy(&intervalLength, bytes.advanced(by: offset + 4), 4)
offset += 8
ranges.insert(contentsOf: Int64(intervalOffset) ..< Int64(intervalOffset + intervalLength))
sum += intervalLength
}
return true
}) {
throw FileMapError.generic
}
let mappedTruncationSize: Int64?
if truncationSizeValue == -1 {
mappedTruncationSize = nil
} else {
mappedTruncationSize = Int64(truncationSizeValue)
}
result = MediaBoxFileMap(
sum: Int64(sum),
ranges: ranges,
truncationSize: mappedTruncationSize,
progress: nil
)
}
}
guard let result = result else {
throw FileMapError.generic
}
return result
}
func serialize(manager: MediaBoxFileManager, to path: String) {
guard let fileItem = manager.open(path: path, mode: .readwrite) else {
postboxLog("MediaBoxFile: serialize: cannot open file")
return
}
let _ = try? fileItem.access { file in
file.seek(position: 0)
let buffer = WriteBuffer()
var magic: UInt32 = 0x7bac1487
buffer.write(&magic, offset: 0, length: 4)
var zero: Int32 = 0
buffer.write(&zero, offset: 0, length: 4)
let rangeView = self.ranges.ranges
var count: Int32 = Int32(rangeView.count)
buffer.write(&count, offset: 0, length: 4)
var truncationSizeValue: Int64 = self.truncationSize ?? -1
buffer.write(&truncationSizeValue, offset: 0, length: 8)
for range in rangeView {
var intervalOffset = range.lowerBound
var intervalLength = range.upperBound - range.lowerBound
buffer.write(&intervalOffset, offset: 0, length: 8)
buffer.write(&intervalLength, offset: 0, length: 8)
}
var crc: UInt32 = Crc32(buffer.memory.advanced(by: 4 + 4 + 4), Int32(buffer.length - (4 + 4 + 4)))
memcpy(buffer.memory.advanced(by: 4), &crc, 4)
let written = file.write(buffer.memory, count: buffer.length)
assert(written == buffer.length)
}
var crc: UInt32 = Crc32(buffer.memory.advanced(by: 4 + 4 + 4), Int32(buffer.length - (4 + 4 + 4)))
memcpy(buffer.memory.advanced(by: 4), &crc, 4)
let written = file.write(buffer.memory, count: buffer.length)
assert(written == buffer.length)
}
fileprivate func fill(_ range: Range<Int64>) {
@ -243,12 +459,12 @@ private class MediaBoxPartialFileDataRequest {
final class MediaBoxPartialFile {
private let queue: Queue
private let manager: MediaBoxFileManager
private let path: String
private let metaPath: String
private let completePath: String
private let completed: (Int64) -> Void
private let metadataFd: ManagedFile
private let fd: ManagedFile
private let fd: MediaBoxFileManager.Item
fileprivate let fileMap: MediaBoxFileMap
private var dataRequests = Bag<MediaBoxPartialFileDataRequest>()
private let missingRanges: MediaBoxFileMissingRanges
@ -260,17 +476,17 @@ final class MediaBoxPartialFile {
private var currentFetch: (Promise<[(Range<Int64>, MediaBoxFetchPriority)]>, Disposable)?
private var processedAtLeastOneFetch: Bool = false
init?(queue: Queue, path: String, metaPath: String, completePath: String, completed: @escaping (Int64) -> Void) {
init?(queue: Queue, manager: MediaBoxFileManager, path: String, metaPath: String, completePath: String, completed: @escaping (Int64) -> Void) {
assert(queue.isCurrent())
if let metadataFd = ManagedFile(queue: queue, path: metaPath, mode: .readwrite), let fd = ManagedFile(queue: queue, path: path, mode: .readwrite) {
self.manager = manager
if let fd = manager.open(path: path, mode: .readwrite) {
self.queue = queue
self.path = path
self.metaPath = metaPath
self.completePath = completePath
self.completed = completed
self.metadataFd = metadataFd
self.fd = fd
if let fileMap = MediaBoxFileMap(fd: self.metadataFd) {
if let fileMap = try? MediaBoxFileMap.read(manager: manager, path: self.metaPath) {
if !fileMap.ranges.isEmpty {
let upperBound = fileMap.ranges.ranges.last!.upperBound
if let actualSize = fileSize(path, useTotalFileAllocatedSize: false) {
@ -298,14 +514,11 @@ final class MediaBoxPartialFile {
self.currentFetch?.1.dispose()
}
static func extractPartialData(path: String, metaPath: String, range: Range<Int64>) -> Data? {
guard let metadataFd = ManagedFile(queue: nil, path: metaPath, mode: .read) else {
return nil
}
static func extractPartialData(manager: MediaBoxFileManager, path: String, metaPath: String, range: Range<Int64>) -> Data? {
guard let fd = ManagedFile(queue: nil, path: path, mode: .read) else {
return nil
}
guard let fileMap = MediaBoxFileMap(fd: metadataFd) else {
guard let fileMap = try? MediaBoxFileMap.read(manager: manager, path: metaPath) else {
return nil
}
guard let clippedRange = fileMap.contains(range) else {
@ -324,7 +537,7 @@ final class MediaBoxPartialFile {
assert(self.queue.isCurrent())
self.fileMap.reset()
self.fileMap.serialize(to: self.metadataFd)
self.fileMap.serialize(manager: self.manager, to: self.metaPath)
for request in self.dataRequests.copyItems() {
request.completion(MediaResourceData(path: self.path, offset: request.range.lowerBound, size: 0, complete: false))
@ -428,7 +641,7 @@ final class MediaBoxPartialFile {
let range: Range<Int64> = size ..< Int64.max
self.fileMap.truncate(size)
self.fileMap.serialize(to: self.metadataFd)
self.fileMap.serialize(manager: self.manager, to: self.metaPath)
self.checkDataRequestsAfterFill(range: range)
}
@ -443,16 +656,23 @@ final class MediaBoxPartialFile {
func write(offset: Int64, data: Data, dataRange: Range<Int64>) {
assert(self.queue.isCurrent())
self.fd.seek(position: offset)
let written = data.withUnsafeBytes { rawBytes -> Int in
let bytes = rawBytes.baseAddress!.assumingMemoryBound(to: UInt8.self)
do {
try self.fd.access { fd in
fd.seek(position: offset)
let written = data.withUnsafeBytes { rawBytes -> Int in
let bytes = rawBytes.baseAddress!.assumingMemoryBound(to: UInt8.self)
return self.fd.write(bytes.advanced(by: Int(dataRange.lowerBound)), count: dataRange.count)
return fd.write(bytes.advanced(by: Int(dataRange.lowerBound)), count: dataRange.count)
}
assert(written == dataRange.count)
}
} catch let e {
postboxLog("MediaBoxPartialFile.write error: \(e)")
}
assert(written == dataRange.count)
let range: Range<Int64> = offset ..< (offset + Int64(dataRange.count))
self.fileMap.fill(range)
self.fileMap.serialize(to: self.metadataFd)
self.fileMap.serialize(manager: self.manager, to: self.metaPath)
self.checkDataRequestsAfterFill(range: range)
}
@ -536,16 +756,25 @@ final class MediaBoxPartialFile {
assert(self.queue.isCurrent())
if let actualRange = self.fileMap.contains(range) {
self.fd.seek(position: Int64(actualRange.lowerBound))
var data = Data(count: actualRange.count)
let dataCount = data.count
let readBytes = data.withUnsafeMutableBytes { rawBytes -> Int in
let bytes = rawBytes.baseAddress!.assumingMemoryBound(to: Int8.self)
return self.fd.read(bytes, dataCount)
}
if readBytes == data.count {
return data
} else {
do {
var result: Data?
try self.fd.access { fd in
fd.seek(position: Int64(actualRange.lowerBound))
var data = Data(count: actualRange.count)
let dataCount = data.count
let readBytes = data.withUnsafeMutableBytes { rawBytes -> Int in
let bytes = rawBytes.baseAddress!.assumingMemoryBound(to: Int8.self)
return fd.read(bytes, dataCount)
}
if readBytes == data.count {
result = data
} else {
result = nil
}
}
return result
} catch let e {
postboxLog("MediaBoxPartialFile.read error: \(e)")
return nil
}
} else {
@ -954,7 +1183,7 @@ final class MediaBoxFileContext {
return self.references.isEmpty
}
init?(queue: Queue, path: String, partialPath: String, metaPath: String) {
init?(queue: Queue, manager: MediaBoxFileManager, path: String, partialPath: String, metaPath: String) {
assert(queue.isCurrent())
self.queue = queue
@ -965,7 +1194,7 @@ final class MediaBoxFileContext {
var completeImpl: ((Int64) -> Void)?
if let size = fileSize(path) {
self.content = .complete(path, size)
} else if let file = MediaBoxPartialFile(queue: queue, path: partialPath, metaPath: metaPath, completePath: path, completed: { size in
} else if let file = MediaBoxPartialFile(queue: queue, manager: manager, path: partialPath, metaPath: metaPath, completePath: path, completed: { size in
completeImpl?(size)
}) {
self.content = .partial(file)