perf: hardware-adaptive parallel scanning & fast Darwin fts traversal

.github/workflows/scan-validation.yml

@@ -0,0 +1,39 @@
+name: Scan validation
+
+on:
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  macos:
+    runs-on: macos-15
+    timeout-minutes: 25
+    steps:
+      - uses: actions/checkout@v4
+      - name: Select project toolchain
+        run: |
+          sudo xcode-select --switch /Applications/Xcode_26.3.app/Contents/Developer
+          swift --version
+      - name: Unit and mounted-volume regression tests
+        env:
+          CLEARDISK_TEST_MOUNTS: "1"
+        run: swift test
+      - name: Parallel measurement race checks
+        run: swift test --sanitize=thread --filter DirectoryMeasurementTests.testParallelMeasurementsHaveIndependentState
+      - name: Universal app and final signature
+        run: |
+          bash scripts/build_app.sh
+          codesign --verify --deep --strict ClearDisk.app
+      - name: Staging failure tests
+        run: python3 scripts/test_stage_sign_app.py
+      - name: Benchmark harness smoke test
+        run: |
+          fixture=$(mktemp -d)
+          trap 'rm -rf "$fixture"' EXIT
+          mkdir "$fixture/one" "$fixture/two"
+          dd if=/dev/zero of="$fixture/one/data" bs=4096 count=4
+          dd if=/dev/zero of="$fixture/two/data" bs=4096 count=8
+          BENCH_RUNS=2 bash scripts/benchmark_scan.sh "$fixture/one" "$fixture/two"

Resources/en.lproj/Localizable.strings

@@ -1,2 +1,6 @@
 /* ClearDisk — English (en) is the development language.
    Keys are the English source strings themselves, so this table is intentionally empty. */
+
+// Scan completeness and resource policy
+"Analysis incomplete: some locations could not be measured." = "Analysis incomplete: some locations could not be measured.";
+"Scan stopped to reduce power or thermal load. Start again to scan with fewer workers." = "Scan stopped to reduce power or thermal load. Start again to scan with fewer workers.";

Resources/tr.lproj/Localizable.strings

@@ -590,3 +590,7 @@
 "The downloaded update payload, staging copy, updater state, and updater logs." = "İndirilen güncelleme paketi, hazırlık kopyası, güncelleyici durumu ve güncelleyici günlükleri.";
 "The installed app, its settings, accounts, and documents." = "Kurulu uygulama, ayarları, hesapları ve belgeleri.";
 "Your account, playlists, local files, and explicitly downloaded offline library." = "Hesabınız, çalma listeleriniz, yerel dosyalarınız ve bilerek indirdiğiniz çevrimdışı kitaplığınız.";
+
+// Scan completeness and resource policy
+"Analysis incomplete: some locations could not be measured." = "Analiz tamamlanamadı: bazı konumlar ölçülemedi.";
+"Scan stopped to reduce power or thermal load. Start again to scan with fewer workers." = "Güç tüketimini veya ısınmayı azaltmak için tarama durduruldu. Daha az eşzamanlı işlemle taramak için yeniden başlatın.";

Sources/ClearDisk/AppCacheCatalog.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-enum CacheSection: String, CaseIterable {
+enum CacheSection: String, CaseIterable, Sendable {
     case app
     case developer
 
@@ -19,7 +19,7 @@ enum CacheSection: String, CaseIterable {
     }
 }
 
-struct CacheSafetyDetails {
+struct CacheSafetyDetails: Sendable {
     let removes: String
     let keeps: String
     let note: String

Sources/ClearDisk/DirectoryMeasurement.swift

@@ -0,0 +1,86 @@
+import Darwin
+import Foundation
+
+struct DirectoryMeasurement: Sendable {
+    var bytes: Int64 = 0
+    var files: Int = 0
+    var errorCount: Int = 0
+    var firstError: String?
+    var isComplete: Bool { errorCount == 0 }
+
+    mutating func recordError(path: String, code: Int32) {
+        errorCount += 1
+        if firstError == nil {
+            firstError = "\(path): \(NSError(domain: NSPOSIXErrorDomain, code: Int(code)).localizedDescription)"
+        }
+    }
+
+    /// Allocated bytes attributed to directory entries, not a promise of space reclaimed.
+    /// Hard links share an allocation; deleting one of several links need not free any blocks.
+    static func measure(path: String, isCancelled: () -> Bool = { false }) -> Self {
+        var result = Self()
+        guard !isCancelled() else {
+            result.recordError(path: path, code: ECANCELED)
+            return result
+        }
+        guard let cPath = strdup(path) else {
+            result.recordError(path: path, code: ENOMEM)
+            return result
+        }
+        defer { free(cPath) }
+
+        // Missing optional cache roots are empty. Other errors must remain visible.
+        var rootStat = stat()
+        if lstat(cPath, &rootStat) != 0 {
+            let code = errno
+            if code != ENOENT { result.recordError(path: path, code: code) }
+            return result
+        }
+
+        var paths: [UnsafeMutablePointer<CChar>?] = [cPath, nil]
+        // Keep argv storage alive for the entire traversal; each call owns its FTS handle.
+        paths.withUnsafeMutableBufferPointer { buffer in
+            guard let tree = fts_open(buffer.baseAddress!, FTS_PHYSICAL | FTS_NOCHDIR | FTS_XDEV, nil) else {
+                result.recordError(path: path, code: errno)
+                return
+            }
+            defer {
+                if fts_close(tree) != 0 { result.recordError(path: path, code: errno) }
+            }
+            while true {
+                if isCancelled() {
+                    result.recordError(path: path, code: ECANCELED)
+                    break
+                }
+                errno = 0
+                guard let node = fts_read(tree) else {
+                    let code = errno
+                    if code != 0 { result.recordError(path: path, code: code) }
+                    break
+                }
+                switch Int32(node.pointee.fts_info) {
+                case FTS_F:
+                    let metadata = node.pointee.fts_statp.pointee
+                    let (allocated, overflow) = max(0, Int64(metadata.st_blocks)).multipliedReportingOverflow(by: 512)
+                    let (total, sumOverflow) = result.bytes.addingReportingOverflow(
+                        allocated / max(1, Int64(metadata.st_nlink))
+                    )
+                    if overflow || sumOverflow {
+                        result.recordError(path: path, code: EOVERFLOW)
+                        return
+                    }
+                    result.bytes = total
+                    result.files += 1
+                case FTS_DC:
+                    result.recordError(path: String(cString: node.pointee.fts_path), code: ELOOP)
+                case FTS_DNR, FTS_ERR, FTS_NS:
+                    let code = node.pointee.fts_errno
+                    result.recordError(path: String(cString: node.pointee.fts_path), code: code == 0 ? EIO : code)
+                default:
+                    break
+                }
+            }
+        }
+        return result
+    }
+}