github.com/OlehKulykov/LzmaSDKObjC @2.1.1

It's not yet another wrapper around C part of the [LZMA SDK] with all it's limitations.
Based on C++ [LZMA SDK] version 19.00 (1900 - latest for now) and patched for iOS & Mac OS platforms.
Can be used with Swift and Objective-C.

Description

---

It's not yet another wrapper around C part of the [LZMA SDK] with all it's limitations. Based on C++ [LZMA SDK] version 19.00 (1900 - latest for now) and patched for iOS & Mac OS platforms.

The main advantages is: - List, extract 7z files (Lzma & Lzma2 compression method). - List, extract encrypted (password protected) 7z files (Lzma & Lzma2 compression method). - List, extract encrypted (password protected) + encrypted header (no visible content, files list, without password) 7z files (Lzma & Lzma2 compression method). - Create 7z archives (Lzma & Lzma2 compression method). - Create encrypted (password protected) 7z archives (Lzma & Lzma2 compression method). - Create encrypted (password protected) + encrypted header (no visible content, files list, without password) 7z archives (Lzma & Lzma2 compression method). - Manage memory allocations during listing/extracting. See below section: Tune up speed, performance and disk IO operations. - Tuned up for using less than 500Kb for listing/extracting, can be easly changed runtime (no hardcoded definitions). See below section: Tune up speed, performance and disk IO operations. - Manage IO read/write operations, aslo can be easly changed runtime (no hardcoded definitions). See below section: Tune up speed, performance and disk IO operations. - Track smoothed progress, which becomes possible with prev. - Support reading and extracting archive files with size more than 4GB. - UTF8 support. - Extra compression/decompression functionality of single NSData object with Lzma2.

Installation with [CocoaPods]

Podfile

use_frameworks!
platform :ios, '9.0'

target '<REPLACE_WITH_YOUR_TARGET>' do
    pod 'LzmaSDK-ObjC', :inhibit_warnings => true
end

Use frameworks (dynamic linking) to include Lzma codecs code in your application.

Example Swift and Objective-C

---

List and extract

Create and setup reader with archive path and/or archive type, optionaly delegate and optionaly password getter block, in case of encrypted archive

Swift

import LzmaSDK_ObjC
...

// select full path to archive file with 7z extension
let archivePath = "path to archive"

// 1.1 Create reader object.
let reader = LzmaSDKObjCReader(fileURL: NSURL(fileURLWithPath: archivePath)
// 1.2 Or create with predefined archive type if path doesn't containes suitable extension
let reader = LzmaSDKObjCReader(fileURL: NSURL(fileURLWithPath: archivePath), andType: LzmaSDKObjCFileType7z)

// Optionaly: assign delegate for tracking extract progress.
reader.delegate = self

// If achive encrypted - define password getter handler.
// NOTES:
// - Encrypted file needs password for extract process.
// - Encrypted file with encrypted header needs password for list(iterate) and extract archive items.
reader.passwordGetter = {
    return "password to my achive"
}
...

// Delegate extension
extension ReaderDelegateObject: LzmaSDKObjCReaderDelegate {
    func onLzmaSDKObjCReader(reader: LzmaSDKObjCReader, extractProgress progress: Float) {
        print("Reader progress: \(progress) %")
    }
}

Objective-C

// select full path to archive file with 7z extension
NSString * archivePath = <path to archive>;

// 1.1 Create and hold strongly reader object.
self.reader = [[LzmaSDKObjCReader alloc] initWithFileURL:[NSURL fileURLWithPath:archivePath]];
// 1.2 Or create with predefined archive type if path doesn't containes suitable extension
self.reader = [[LzmaSDKObjCReader alloc] initWithFileURL:[NSURL fileURLWithPath:archivePath]
                         andType:LzmaSDKObjCFileType7z];

// Optionaly: assign weak delegate for tracking extract progress.
_reader.delegate = self;

// If achive encrypted - define password getter handler.
// NOTES:
// - Encrypted file needs password for extract process.
// - Encrypted file with encrypted header needs password for list(iterate) and extract archive items.
_reader.passwordGetter = ^NSString*(void){
    return @"password to my achive";
};

Open archive, e.g. find out type of achive, locate decoder and read archive header

Swift

// Try open archive.
do {
    try reader.open()
}
catch let error as NSError {
    print("Can't open archive: \(error.localizedDescription) ")
}

Objective-C

// Open archive, with or without error. Error can be nil.
NSError * error = nil;
if (![_reader open:&error]) {
    NSLog(@"Open error: %@", error);
}
NSLog(@"Open error: %@", _reader.lastError);

Iterate archive items, select and store required items for future processing

Swift

var items = [LzmaSDKObjCItem]()  // Array with selected items.
// Iterate all archive items, track what items do you need & hold them in array.
reader.iterateWithHandler({(item: LzmaSDKObjCItem, error: NSError?) -> Bool in
    items.append(item) // if needs this item - store to array.
    return true // true - continue iterate, false - stop iteration
})

Objective-C

NSMutableArray * items = [NSMutableArray array]; // Array with selected items.
// Iterate all archive items, track what items do you need & hold them in array.
[_reader iterateWithHandler:^BOOL(LzmaSDKObjCItem * item, NSError * error){
    NSLog(@"\n%@", item);
    if (item) [items addObject:item]; // if needs this item - store to array.
    return YES; // YES - continue iterate, NO - stop iteration
}];
NSLog(@"Iteration error: %@", _reader.lastError);

Extract or test archive items

Swift

// Extract selected items from prev. step.
// true - create subfolders structure for the items.
// false - place item file to the root of path(in this case items with the same names will be overwrited automaticaly).
if reader.extract(items, toPath: "/Volumes/Data/1/", withFullPaths: true) {
    print("Extract failed: \(reader.lastError?.localizedDescription)")
}

// Test selected items from prev. step.
if reader.test(items) {
    print("Test failed: \(reader.lastError?.localizedDescription)")
}
````
##### Objective-C
```objc
// Extract selected items from prev. step.
// YES - create subfolders structure for the items.
// NO - place item file to the root of path(in this case items with the same names will be overwrited automaticaly).
[_reader extract:items
          toPath:@"/extract/path"
    withFullPaths:YES]; 
NSLog(@"Extract error: %@", _reader.lastError);

// Test selected items from prev. step.
[_reader test:items];
NSLog(@"test error: %@", _reader.lastError);

Create 7z archive

Swift

// Create writer
let writer = LzmaSDKObjCWriter(fileURL: NSURL(fileURLWithPath: "/Path/MyArchive.7z"))

// Add file data's or paths
writer.addData(NSData(...), forPath: "MyArchiveFileName.txt") // Add file data
writer.addPath("/Path/somefile.txt", forPath: "archiveDir/somefile.txt") // Add file at path
writer.addPath("/Path/SomeDirectory", forPath: "SomeDirectory") // Recursively add directory with all contents

// Setup writer
writer.delegate = self // Track progress
writer.passwordGetter = { // Password getter
    return "1234"
}

// Optional settings 
writer.method = LzmaSDKObjCMethodLZMA2 // or LzmaSDKObjCMethodLZMA
writer.solid = true
writer.compressionLevel = 9
writer.encodeContent = true
writer.encodeHeader = true
writer.compressHeader = true
writer.compressHeaderFull = true
writer.writeModificationTime = false
writer.writeCreationTime = false
writer.writeAccessTime = false

// Open archive file
do {
    try writer.open()
} catch let error as NSError {
    print(error.localizedDescription)
}

// Write archive within current thread
writer.write()

// or
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0)) {
    writer.write()
}

Objective-C

// Create writer
LzmaSDKObjCWriter * writer = [[LzmaSDKObjCWriter alloc] initWithFileURL:[NSURL fileURLWithPath:@"/Path/MyArchive.7z"]];

// Add file data's or paths
[writer addData:[NSData ...] forPath:@"MyArchiveFileName.txt"]; // Add file data
[writer addPath:@"/Path/somefile.txt" forPath:@"archiveDir/somefile.txt"]; // Add file at path
[writer addPath:@"/Path/SomeDirectory" forPath:@"SomeDirectory"]; // Recursively add directory with all contents

// Setup writer
writer.delegate = self; // Track progress
writer.passwordGetter = ^NSString*(void) { // Password getter
    return @"1234";
};

// Optional settings 
writer.method = LzmaSDKObjCMethodLZMA2; // or LzmaSDKObjCMethodLZMA
writer.solid = YES;
writer.compressionLevel = 9;
writer.encodeContent = YES;
writer.encodeHeader = YES;
writer.compressHeader = YES;
writer.compressHeaderFull = YES;
writer.writeModificationTime = NO;
writer.writeCreationTime = NO;
writer.writeAccessTime = NO;

// Open archive file
NSError * error = nil;
[writer open:&error];

// Write archive within current thread
[writer write];

// or
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
    [writer write];
});

Compress/decompress single data buffer

Swift

// Compress data with compression maximum compression ratio.
let compressedData = LzmaSDKObjCBufferCompressLZMA2(sourceData, 1)
// Decompress previvously compressed data.
let decompressedData = LzmaSDKObjCBufferDecompressLZMA2(compressedData)

Objective-C

// Compress data with compression maximum compression ratio.
NSData * compressedData = LzmaSDKObjCBufferCompressLZMA2(sourceData, 1);
// Decompress previvously compressed data.
NSData * decompressedData = LzmaSDKObjCBufferDecompressLZMA2(compressedData);

Tune up speed, performance and disk IO operations

---

Original C++ part of the [LZMA SDK] was patched to have a possibility to tune up default(hardcoded) settings. For list and extract functionality was defined next global variables: kLzmaSDKObjCStreamReadSize, kLzmaSDKObjCStreamWriteSize, kLzmaSDKObjCDecoderReadSize and kLzmaSDKObjCDecoderWriteSize. This variables holds size values in bytes, so, for the single reader object summary of this 4's values will be allocated.

Keep in mind: operations with memory much more faster than disk IO operations, so read below situations:

switch (<what do I need ?>) {
    case <I need faster list and extract>:
        //TODO: Increase stream and decoder size of buffers
        Result:
            1. more allocated memory
            2. less IO read/write operations and less delays
            3. less smoothed progress
            4. more CPU load (do a job, not distracted to read/write data)
        break;

    case <I need use less memory or more smoothed progress>:
        //TODO: Decrease stream and decoder size of buffers
        Result:
            1. less allocated memory
            2. more IO read/write operations and more delays
            3. more smoothed progress
            4. less CPU load (wait for read/write data)
        break;

    default:
        //TODO: use current settings
        break;
    };

NOTE: Modify global variables before creating & using reader object.

NOTE: This allocation sizes doesn't affet to memory allocated for the archive dictionary.

Features list (TODO/DONE)

---

• [x] Lzma/*.7z
• [x] List
  • [x] Regular archive. tests/files/lzma.7z
  • [x] Encrypted archive with AES256. tests/files/lzma_aes256.7z
  • [x] Encrypted archive + encrypted header(no visible content, files list, without password) with AES256. tests/files/lzma_aes256_encfn.7z
• [x] Extract
  • [x] Regular archive. tests/files/lzma.7z
  • [x] Encrypted archive with AES256. tests/files/lzma_aes256.7z
  • [x] Encrypted archive + encrypted header(no visible content, files list, without password) with AES256. tests/files/lzma_aes256_encfn.7z
• [x] Create
  • [x] Regular archive.
  • [x] Encrypted archive with AES256.
  • [x] Encrypted archive + encrypted header(no visible content, files list, without password) with AES256.
• [x] Lzma2/*.7z
• [x] List
  • [x] Regular archive. tests/files/lzma2.7z
  • [x] Encrypted archive with AES256. tests/files/lzma2_aes256.7z
  • [x] Encrypted archive + encrypted header(no visible content, files list, without password) with AES256. tests/files/lzma2_aes256_encfn.7z
• [x] Extract
  • [x] Regular archive. tests/files/lzma2.7z
  • [x] Encrypted archive with AES256. tests/files/lzma2_aes256.7z
  • [x] Encrypted archive + encrypted header(no visible content, files list, without password) with AES256. tests/files/lzma2_aes256_encfn.7z
• [x] Create
  • [x] Regular archive.
  • [x] Encrypted archive with AES256.
  • [x] Encrypted archive + encrypted header(no visible content, files list, without password) with AES256.
• [ ] Omit unused code, reduce buildable, original code size.

License

---

By using this all you are accepting original [LZMA SDK] and MIT license (see below):

The MIT License (MIT)

Copyright (c) 2015 - 2019 Kulykov Oleh info@resident.name

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Sof