feat: new compression wrapper using LZFSE

Sources/InfomaniakCore/Extensions/Data+Compression.swift

@@ -0,0 +1,50 @@
+/*
+ Infomaniak Core - iOS
+ Copyright (C) 2023 Infomaniak Network SA
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import Foundation
+
+/// LZFSE Wrapper
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+public extension Data {
+    /// Compressed data using a zstd like algorithm: lzfse
+    func compressed() -> Self? {
+        guard let data = try? (self as NSData).compressed(using: .lzfse) as Data else {
+            return nil
+        }
+        return data
+    }
+
+    /// Decompressed data from a lzfse buffer
+    func decompressed() -> Self? {
+        guard let data = try? (self as NSData).decompressed(using: .lzfse) as Data else {
+            return nil
+        }
+        return data
+    }
+
+    // MARK: - String helpers
+
+    /// Decompressed string from a lzfse buffer
+    func decompressedString() -> String? {
+        guard let decompressedData = decompressed() else {
+            return nil
+        }
+        let string = String(decoding: decompressedData, as: UTF8.self)
+        return string
+    }
+}

Sources/InfomaniakCore/Extensions/String+Compression.swift

@@ -0,0 +1,35 @@
+/*
+ Infomaniak Core - iOS
+ Copyright (C) 2023 Infomaniak Network SA
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import Foundation
+
+/// LZFSE Wrapper
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+public extension String {
+    func compressed() -> Data? {
+        guard let data = data(using: .utf8),
+              let compressed = data.compressed() else {
+            return nil
+        }
+        return compressed
+    }
+
+    static func decompressed(from data: Data) -> Self? {
+        data.decompressedString()
+    }
+}

Tests/InfomaniakCoreTests/UTCompression.swift

@@ -0,0 +1,54 @@
+/*
+ Infomaniak Core - iOS
+ Copyright (C) 2023 Infomaniak Network SA
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import InfomaniakCore
+import XCTest
+
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+final class UTCompression: XCTestCase {
+    func testCompression() {
+        // GIVEN
+        let lowEntropy = "eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee"
+        let lowEntropyData = lowEntropy.data(using: .utf8)!
+
+        // WHEN
+        guard let highEntropy = lowEntropy.compressed() else {
+            XCTFail("Unexpected")
+            return
+        }
+
+        // THEN
+        XCTAssertLessThan(highEntropy.count, lowEntropyData.count, "Compressed message should be smaller")
+    }
+
+    func testCompressionDecompression() {
+        // GIVEN
+        let lowEntropy = "eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee"
+
+        // WHEN
+        guard let highEntropy = lowEntropy.compressed() else {
+            XCTFail("Unexpected")
+            return
+        }
+
+        let decompressedString = highEntropy.decompressedString()
+
+        // THEN
+        XCTAssertEqual(lowEntropy, decompressedString)
+    }
+}