feat(telemetry): implement real-time disk I/O throughput and IOPS provider (fixes #10)

Sources/Bridging/MacMonitor-Bridging-Header.h

@@ -19,5 +19,8 @@
 #import "MMFanTelemetryProvider.h"
 #import "MMComponentThermalProvider.h"
 #import "MMPowerTelemetryProvider.h"
+#import "MMKernelTelemetryProvider.h"
+#import "MMLoadAverageProvider.h"
+#import "MMDiskIOProvider.h"
 
 #endif /* MacMonitor_Bridging_Header_h */

Sources/Telemetry/Kernel/MMKernelTelemetryProvider.h

@@ -0,0 +1,30 @@
+#ifndef MMKernelTelemetryProvider_h
+#define MMKernelTelemetryProvider_h
+
+#import <Foundation/Foundation.h>
+#import "MMTelemetryProvider.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * MMKernelTelemetryProvider
+ * Samples low-level Mach kernel performance counters: context switches, system calls,
+ * page faults (soft, COW, zero-fill), pageins/pageouts, and computes instantaneous rates per second.
+ */
+@interface MMKernelTelemetryProvider : NSObject <MMTelemetryProvider>
+
+- (instancetype)init;
+
+/**
+ * Static calculator method for deterministic unit testing.
+ * Computes event rates per second based on previous and current cumulative counters over delta time.
+ */
++ (NSDictionary<NSString *, id> *)calculateRatesWithCurrentCounters:(NSDictionary<NSString *, NSNumber *> *)current
+                                                   previousCounters:(nullable NSDictionary<NSString *, NSNumber *> *)previous
+                                                          timeDelta:(NSTimeInterval)timeDelta;
+
+@end
+
+NS_ASSUME_NONNULL_END
+
+#endif /* MMKernelTelemetryProvider_h */

Sources/Telemetry/Kernel/MMKernelTelemetryProvider.m

@@ -0,0 +1,131 @@
+#import "MMKernelTelemetryProvider.h"
+#import <mach/mach.h>
+#import <mach/mach_time.h>
+#import <libproc.h>
+#import <os/lock.h>
+
+@interface MMKernelTelemetryProvider () {
+    os_unfair_lock _lock;
+    NSDictionary<NSString *, NSNumber *> *_previousCounters;
+    uint64_t _previousTimestamp;
+    mach_timebase_info_data_t _timebase;
+}
+@end
+
+@implementation MMKernelTelemetryProvider
+
+- (instancetype)init {
+    self = [super init];
+    if (self) {
+        _lock = OS_UNFAIR_LOCK_INIT;
+        _previousCounters = nil;
+        _previousTimestamp = 0;
+        mach_timebase_info(&_timebase);
+    }
+    return self;
+}
+
+- (MMTelemetryDomain)domain {
+    return MMTelemetryDomainSystem;
+}
+
+- (NSString *)providerIdentifier {
+    return @"com.i3omb.macmonitor.telemetry.kernel.counters";
+}
+
+- (BOOL)isAvailable {
+    return YES;
+}
+
++ (NSDictionary<NSString *, id> *)calculateRatesWithCurrentCounters:(NSDictionary<NSString *, NSNumber *> *)current
+                                                   previousCounters:(nullable NSDictionary<NSString *, NSNumber *> *)previous
+                                                          timeDelta:(NSTimeInterval)timeDelta {
+    NSMutableDictionary<NSString *, id> *result = [NSMutableDictionary dictionary];
+    
+    // Copy all current cumulative counters into result
+    [current enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSNumber *val, BOOL *stop) {
+        result[[@"cumulative_" stringByAppendingString:key]] = val;
+    }];
+    
+    NSArray<NSString *> *rateKeys = @[
+        @"contextSwitches", @"syscalls", @"pageFaults", @"cowFaults",
+        @"zeroFills", @"pageins", @"pageouts", @"decompressions", @"compressions"
+    ];
+    
+    for (NSString *key in rateKeys) {
+        double currentVal = [current[key] doubleValue];
+        double prevVal = previous ? [previous[key] doubleValue] : currentVal;
+        double delta = (currentVal >= prevVal) ? (currentVal - prevVal) : 0.0;
+        double rate = (timeDelta > 0.0001) ? (delta / timeDelta) : 0.0;
+        result[[key stringByAppendingString:@"Rate"]] = @(rate);
+    }
+    
+    result[@"timeDelta"] = @(timeDelta);
+    return result;
+}
+
+- (nullable NSDictionary<NSString *, id> *)sampleTelemetryWithError:(NSError **)error {
+    uint64_t now = mach_absolute_time();
+    
+    // 1. Query Mach VM Statistics for page faults, COW, zero fills, pageins/outs
+    vm_statistics64_data_t vmStats;
+    mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
+    kern_return_t kr = host_statistics64(mach_host_self(), HOST_VM_INFO64, (host_info64_t)&vmStats, &count);
+    if (kr != KERN_SUCCESS) {
+        if (error) {
+            *error = [NSError errorWithDomain:@"com.i3omb.macmonitor.kernel"
+                                         code:kr
+                                     userInfo:@{NSLocalizedDescriptionKey: @"Failed to query host_statistics64"}];
+        }
+        return nil;
+    }
+    
+    // 2. Query process table for cumulative context switches and system calls
+    int pids[4096];
+    int bytes = proc_listpids(PROC_ALL_PIDS, 0, pids, sizeof(pids));
+    int pidCount = bytes / sizeof(int);
+    
+    uint64_t totalCSW = 0;
+    uint64_t totalSyscalls = 0;
+    
+    for (int i = 0; i < pidCount; i++) {
+        if (pids[i] <= 0) continue;
+        struct proc_taskinfo ti;
+        if (proc_pidinfo(pids[i], PROC_PIDTASKINFO, 0, &ti, sizeof(ti)) == sizeof(ti)) {
+            totalCSW += ti.pti_csw;
+            totalSyscalls += (uint64_t)ti.pti_syscalls_unix + (uint64_t)ti.pti_syscalls_mach;
+        }
+    }
+    
+    NSDictionary<NSString *, NSNumber *> *currentCounters = @{
+        @"contextSwitches": @(totalCSW),
+        @"syscalls": @(totalSyscalls),
+        @"pageFaults": @(vmStats.faults),
+        @"cowFaults": @(vmStats.cow_faults),
+        @"zeroFills": @(vmStats.zero_fill_count),
+        @"pageins": @(vmStats.pageins),
+        @"pageouts": @(vmStats.pageouts),
+        @"decompressions": @(vmStats.decompressions),
+        @"compressions": @(vmStats.compressions)
+    };
+    
+    os_unfair_lock_lock(&_lock);
+    NSDictionary<NSString *, NSNumber *> *prev = _previousCounters;
+    uint64_t prevTime = _previousTimestamp;
+    
+    _previousCounters = currentCounters;
+    _previousTimestamp = now;
+    os_unfair_lock_unlock(&_lock);
+    
+    NSTimeInterval timeDelta = 1.0;
+    if (prevTime > 0) {
+        uint64_t elapsed = now - prevTime;
+        timeDelta = (double)elapsed * _timebase.numer / _timebase.denom / 1e9;
+    }
+    
+    return [MMKernelTelemetryProvider calculateRatesWithCurrentCounters:currentCounters
+                                                       previousCounters:prev
+                                                              timeDelta:timeDelta];
+}
+
+@end

Sources/Telemetry/Storage/MMDiskIOProvider.h

@@ -0,0 +1,29 @@
+#ifndef MMDiskIOProvider_h
+#define MMDiskIOProvider_h
+
+#import <Foundation/Foundation.h>
+#import "MMTelemetryProvider.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * MMDiskIOProvider
+ * Samples real-time storage disk transfer rates (read/write bytes per second)
+ * and transaction rates (read/write IOPS) across internal and external block storage devices.
+ */
+@interface MMDiskIOProvider : NSObject <MMTelemetryProvider>
+
+- (instancetype)init;
+
+/**
+ * Pure calculator method for deterministic unit testing.
+ */
++ (NSDictionary<NSString *, id> *)calculateDiskIOMetricsWithCurrentSnapshots:(NSDictionary<NSString *, NSDictionary<NSString *, NSNumber *> *> *)current
+                                                           previousSnapshots:(nullable NSDictionary<NSString *, NSDictionary<NSString *, NSNumber *> *> *)previous
+                                                                   timeDelta:(NSTimeInterval)timeDelta;
+
+@end
+
+NS_ASSUME_NONNULL_END
+
+#endif /* MMDiskIOProvider_h */

Sources/Telemetry/Storage/MMDiskIOProvider.m

@@ -0,0 +1,170 @@
+#import "MMDiskIOProvider.h"
+#import <IOKit/IOKitLib.h>
+#import <IOKit/storage/IOBlockStorageDriver.h>
+#import <mach/mach_time.h>
+#import <os/lock.h>
+
+@interface MMDiskIOProvider () {
+    os_unfair_lock _lock;
+    NSDictionary<NSString *, NSDictionary<NSString *, NSNumber *> *> *_previousSnapshots;
+    uint64_t _previousTimestamp;
+    mach_timebase_info_data_t _timebase;
+}
+@end
+
+@implementation MMDiskIOProvider
+
+- (instancetype)init {
+    self = [super init];
+    if (self) {
+        _lock = OS_UNFAIR_LOCK_INIT;
+        _previousSnapshots = nil;
+        _previousTimestamp = 0;
+        mach_timebase_info(&_timebase);
+    }
+    return self;
+}
+
+- (MMTelemetryDomain)domain {
+    return MMTelemetryDomainStorage;
+}
+
+- (NSString *)providerIdentifier {
+    return @"com.i3omb.macmonitor.telemetry.storage.io";
+}
+
+- (BOOL)isAvailable {
+    return YES;
+}
+
++ (NSDictionary<NSString *, id> *)calculateDiskIOMetricsWithCurrentSnapshots:(NSDictionary<NSString *, NSDictionary<NSString *, NSNumber *> *> *)current
+                                                           previousSnapshots:(nullable NSDictionary<NSString *, NSDictionary<NSString *, NSNumber *> *> *)previous
+                                                                   timeDelta:(NSTimeInterval)timeDelta {
+    double totalReadBps = 0.0;
+    double totalWriteBps = 0.0;
+    double totalReadIOPS = 0.0;
+    double totalWriteIOPS = 0.0;
+    
+    NSMutableArray<NSDictionary<NSString *, id> *> *disks = [NSMutableArray arrayWithCapacity:current.count];
+    NSArray<NSString *> *sortedBsdNames = [current.allKeys sortedArrayUsingSelector:@selector(compare:)];
+    
+    for (NSString *bsdName in sortedBsdNames) {
+        NSDictionary<NSString *, NSNumber *> *curr = current[bsdName];
+        NSDictionary<NSString *, NSNumber *> *prev = previous ? previous[bsdName] : nil;
+        
+        uint64_t currReadBytes = [curr[@"readBytes"] unsignedLongLongValue];
+        uint64_t currWriteBytes = [curr[@"writeBytes"] unsignedLongLongValue];
+        uint64_t currReadOps = [curr[@"readOps"] unsignedLongLongValue];
+        uint64_t currWriteOps = [curr[@"writeOps"] unsignedLongLongValue];
+        
+        uint64_t prevReadBytes = prev ? [prev[@"readBytes"] unsignedLongLongValue] : currReadBytes;
+        uint64_t prevWriteBytes = prev ? [prev[@"writeBytes"] unsignedLongLongValue] : currWriteBytes;
+        uint64_t prevReadOps = prev ? [prev[@"readOps"] unsignedLongLongValue] : currReadOps;
+        uint64_t prevWriteOps = prev ? [prev[@"writeOps"] unsignedLongLongValue] : currWriteOps;
+        
+        double deltaReadBytes = (currReadBytes >= prevReadBytes) ? (double)(currReadBytes - prevReadBytes) : 0.0;
+        double deltaWriteBytes = (currWriteBytes >= prevWriteBytes) ? (double)(currWriteBytes - prevWriteBytes) : 0.0;
+        double deltaReadOps = (currReadOps >= prevReadOps) ? (double)(currReadOps - prevReadOps) : 0.0;
+        double deltaWriteOps = (currWriteOps >= prevWriteOps) ? (double)(currWriteOps - prevWriteOps) : 0.0;
+        
+        double readBps = (timeDelta > 0.0001) ? (deltaReadBytes / timeDelta) : 0.0;
+        double writeBps = (timeDelta > 0.0001) ? (deltaWriteBytes / timeDelta) : 0.0;
+        double readIOPS = (timeDelta > 0.0001) ? (deltaReadOps / timeDelta) : 0.0;
+        double writeIOPS = (timeDelta > 0.0001) ? (deltaWriteOps / timeDelta) : 0.0;
+        
+        totalReadBps += readBps;
+        totalWriteBps += writeBps;
+        totalReadIOPS += readIOPS;
+        totalWriteIOPS += writeIOPS;
+        
+        [disks addObject:@{
+            @"bsdName": bsdName,
+            @"readBytesPerSec": @(readBps),
+            @"writeBytesPerSec": @(writeBps),
+            @"readIOPS": @(readIOPS),
+            @"writeIOPS": @(writeIOPS),
+            @"cumulativeReadBytes": @(currReadBytes),
+            @"cumulativeWriteBytes": @(currWriteBytes),
+            @"cumulativeReadOps": @(currReadOps),
+            @"cumulativeWriteOps": @(currWriteOps)
+        }];
+    }
+    
+    return @{
+        @"disks": disks,
+        @"totalReadBytesPerSec": @(totalReadBps),
+        @"totalWriteBytesPerSec": @(totalWriteBps),
+        @"totalReadIOPS": @(totalReadIOPS),
+        @"totalWriteIOPS": @(totalWriteIOPS),
+        @"timeDelta": @(timeDelta)
+    };
+}
+
+- (nullable NSDictionary<NSString *, id> *)sampleTelemetryWithError:(NSError **)error {
+    uint64_t now = mach_absolute_time();
+    
+    NSMutableDictionary<NSString *, NSDictionary<NSString *, NSNumber *> *> *currentSnapshots = [NSMutableDictionary dictionary];
+    
+    CFMutableDictionaryRef matching = IOServiceMatching(kIOBlockStorageDriverClass);
+    io_iterator_t iterator = IO_OBJECT_NULL;
+    if (IOServiceGetMatchingServices(kIOMainPortDefault, matching, &iterator) == KERN_SUCCESS && iterator != IO_OBJECT_NULL) {
+        io_registry_entry_t entry;
+        while ((entry = IOIteratorNext(iterator)) != IO_OBJECT_NULL) {
+            NSString *bsdName = nil;
+            io_iterator_t childIterator;
+            if (IORegistryEntryGetChildIterator(entry, kIOServicePlane, &childIterator) == KERN_SUCCESS) {
+                io_registry_entry_t child;
+                while ((child = IOIteratorNext(childIterator)) != IO_OBJECT_NULL) {
+                    CFTypeRef nameRef = IORegistryEntryCreateCFProperty(child, CFSTR("BSD Name"), kCFAllocatorDefault, 0);
+                    if (nameRef) {
+                        bsdName = CFBridgingRelease(nameRef);
+                        IOObjectRelease(child);
+                        break;
+                    }
+                    IOObjectRelease(child);
+                }
+                IOObjectRelease(childIterator);
+            }
+            
+            if (bsdName) {
+                CFTypeRef statsRef = IORegistryEntryCreateCFProperty(entry, CFSTR("Statistics"), kCFAllocatorDefault, 0);
+                if (statsRef) {
+                    NSDictionary *stats = CFBridgingRelease(statsRef);
+                    NSNumber *readBytes = stats[@"Bytes (Read)"] ?: @0;
+                    NSNumber *writeBytes = stats[@"Bytes (Write)"] ?: @0;
+                    NSNumber *readOps = stats[@"Operations (Read)"] ?: @0;
+                    NSNumber *writeOps = stats[@"Operations (Write)"] ?: @0;
+                    
+                    currentSnapshots[bsdName] = @{
+                        @"readBytes": readBytes,
+                        @"writeBytes": writeBytes,
+                        @"readOps": readOps,
+                        @"writeOps": writeOps
+                    };
+                }
+            }
+            IOObjectRelease(entry);
+        }
+        IOObjectRelease(iterator);
+    }
+    
+    os_unfair_lock_lock(&_lock);
+    NSDictionary<NSString *, NSDictionary<NSString *, NSNumber *> *> *prev = _previousSnapshots;
+    uint64_t prevTime = _previousTimestamp;
+    
+    _previousSnapshots = currentSnapshots;
+    _previousTimestamp = now;
+    os_unfair_lock_unlock(&_lock);
+    
+    NSTimeInterval timeDelta = 1.0;
+    if (prevTime > 0) {
+        uint64_t elapsed = now - prevTime;
+        timeDelta = (double)elapsed * _timebase.numer / _timebase.denom / 1e9;
+    }
+    
+    return [MMDiskIOProvider calculateDiskIOMetricsWithCurrentSnapshots:currentSnapshots
+                                                      previousSnapshots:prev
+                                                              timeDelta:timeDelta];
+}
+
+@end

Sources/Telemetry/System/MMLoadAverageProvider.h

@@ -0,0 +1,33 @@
+#ifndef MMLoadAverageProvider_h
+#define MMLoadAverageProvider_h
+
+#import <Foundation/Foundation.h>
+#import "MMTelemetryProvider.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * MMLoadAverageProvider
+ * Samples 1m, 5m, and 15m system load averages, Mach concurrency factors,
+ * and system-wide task and thread counts.
+ */
+@interface MMLoadAverageProvider : NSObject <MMTelemetryProvider>
+
+- (instancetype)init;
+
+/**
+ * Pure calculator method for deterministic unit testing.
+ */
++ (NSDictionary<NSString *, id> *)calculateLoadMetricsWithLoad1:(double)load1
+                                                          load5:(double)load5
+                                                         load15:(double)load15
+                                                      taskCount:(int)taskCount
+                                                    threadCount:(int)threadCount
+                                                       cpuCount:(int)cpuCount
+                                                     machFactor:(double)machFactor;
+
+@end
+
+NS_ASSUME_NONNULL_END
+
+#endif /* MMLoadAverageProvider_h */

Sources/Telemetry/System/MMLoadAverageProvider.m

@@ -0,0 +1,92 @@
+#import "MMLoadAverageProvider.h"
+#import <mach/mach.h>
+#import <mach/processor_info.h>
+#import <sys/sysctl.h>
+#import <stdlib.h>
+
+@implementation MMLoadAverageProvider
+
+- (instancetype)init {
+    self = [super init];
+    return self;
+}
+
+- (MMTelemetryDomain)domain {
+    return MMTelemetryDomainSystem;
+}
+
+- (NSString *)providerIdentifier {
+    return @"com.i3omb.macmonitor.telemetry.system.load";
+}
+
+- (BOOL)isAvailable {
+    return YES;
+}
+
++ (NSDictionary<NSString *, id> *)calculateLoadMetricsWithLoad1:(double)load1
+                                                          load5:(double)load5
+                                                         load15:(double)load15
+                                                      taskCount:(int)taskCount
+                                                    threadCount:(int)threadCount
+                                                       cpuCount:(int)cpuCount
+                                                     machFactor:(double)machFactor {
+    int safeCpus = cpuCount > 0 ? cpuCount : 1;
+    double norm1 = load1 / (double)safeCpus;
+    double norm5 = load5 / (double)safeCpus;
+    double norm15 = load15 / (double)safeCpus;
+    
+    return @{
+        @"load1m": @(load1),
+        @"load5m": @(load5),
+        @"load15m": @(load15),
+        @"normalizedLoad1m": @(norm1),
+        @"normalizedLoad5m": @(norm5),
+        @"normalizedLoad15m": @(norm15),
+        @"taskCount": @(taskCount),
+        @"threadCount": @(threadCount),
+        @"logicalCpuCount": @(safeCpus),
+        @"machFactor": @(machFactor),
+        @"isOverloaded": @(norm1 > 1.0)
+    };
+}
+
+- (nullable NSDictionary<NSString *, id> *)sampleTelemetryWithError:(NSError **)error {
+    // 1. Get BSD load averages
+    double load[3] = {0.0, 0.0, 0.0};
+    int ret = getloadavg(load, 3);
+    if (ret <= 0) {
+        load[0] = 0.0;
+        load[1] = 0.0;
+        load[2] = 0.0;
+    }
+    
+    // 2. Query Mach processor set for task & thread counts and mach factor
+    mach_port_t host = mach_host_self();
+    processor_set_name_port_t pset = MACH_PORT_NULL;
+    processor_set_load_info_data_t loadInfo = {0};
+    mach_msg_type_number_t count = PROCESSOR_SET_LOAD_INFO_COUNT;
+    
+    kern_return_t kr = processor_set_default(host, &pset);
+    if (kr == KERN_SUCCESS && MACH_PORT_VALID(pset)) {
+        kr = processor_set_statistics(pset, PROCESSOR_SET_LOAD_INFO, (processor_set_info_t)&loadInfo, &count);
+        mach_port_deallocate(mach_task_self(), pset);
+    }
+    
+    double machFactor = (double)loadInfo.mach_factor / (double)LOAD_SCALE;
+    
+    // 3. Query logical CPU core count
+    int cpuCount = 1;
+    size_t size = sizeof(cpuCount);
+    sysctlbyname("hw.logicalcpu", &cpuCount, &size, NULL, 0);
+    if (cpuCount <= 0) cpuCount = 1;
+    
+    return [MMLoadAverageProvider calculateLoadMetricsWithLoad1:load[0]
+                                                          load5:load[1]
+                                                         load15:load[2]
+                                                      taskCount:loadInfo.task_count
+                                                    threadCount:loadInfo.thread_count
+                                                       cpuCount:cpuCount
+                                                     machFactor:machFactor];
+}
+
+@end

Tests/MMDiskIOTests.swift

@@ -0,0 +1,73 @@
+import XCTest
+@testable import MacMonitor
+
+final class MMDiskIOTests: XCTestCase {
+    
+    func testDiskIOMetricsCalculation() {
+        let prev: [String: [String: NSNumber]] = [
+            "disk0": [
+                "readBytes": NSNumber(value: 10_000_000),
+                "writeBytes": NSNumber(value: 5_000_000),
+                "readOps": NSNumber(value: 1_000),
+                "writeOps": NSNumber(value: 500)
+            ],
+            "disk1": [
+                "readBytes": NSNumber(value: 2_000_000),
+                "writeBytes": NSNumber(value: 1_000_000),
+                "readOps": NSNumber(value: 200),
+                "writeOps": NSNumber(value: 100)
+            ]
+        ]
+        
+        let curr: [String: [String: NSNumber]] = [
+            "disk0": [
+                "readBytes": NSNumber(value: 20_000_000), // delta = 10,000,000 bytes
+                "writeBytes": NSNumber(value: 7_000_000),  // delta = 2,000,000 bytes
+                "readOps": NSNumber(value: 1_200),         // delta = 200 ops
+                "writeOps": NSNumber(value: 600)           // delta = 100 ops
+            ],
+            "disk1": [
+                "readBytes": NSNumber(value: 4_000_000),  // delta = 2,000,000 bytes
+                "writeBytes": NSNumber(value: 1_000_000),  // delta = 0
+                "readOps": NSNumber(value: 250),           // delta = 50 ops
+                "writeOps": NSNumber(value: 100)           // delta = 0 ops
+            ]
+        ]
+        
+        let timeDelta: TimeInterval = 2.0 // 2 seconds
+        
+        let metrics = MMDiskIOProvider.calculateDiskIOMetrics(
+            withCurrentSnapshots: curr,
+            previousSnapshots: prev,
+            timeDelta: timeDelta
+        )
+        
+        let totalReadBps = metrics["totalReadBytesPerSec"] as? Double ?? 0
+        let totalWriteBps = metrics["totalWriteBytesPerSec"] as? Double ?? 0
+        let totalReadIOPS = metrics["totalReadIOPS"] as? Double ?? 0
+        let totalWriteIOPS = metrics["totalWriteIOPS"] as? Double ?? 0
+        let disks = metrics["disks"] as? [[String: Any]] ?? []
+        
+        // (10MB + 2MB) / 2s = 6,000,000 B/s
+        XCTAssertEqual(totalReadBps, 6_000_000.0, accuracy: 1.0)
+        // (2MB + 0) / 2s = 1,000,000 B/s
+        XCTAssertEqual(totalWriteBps, 1_000_000.0, accuracy: 1.0)
+        // (200 + 50) / 2s = 125 IOPS
+        XCTAssertEqual(totalReadIOPS, 125.0, accuracy: 0.1)
+        // (100 + 0) / 2s = 50 IOPS
+        XCTAssertEqual(totalWriteIOPS, 50.0, accuracy: 0.1)
+        XCTAssertEqual(disks.count, 2)
+    }
+    
+    func testLiveDiskIOProvider() throws {
+        let provider = MMDiskIOProvider()
+        XCTAssertEqual(provider.domain, .storage)
+        XCTAssertEqual(provider.providerIdentifier, "com.i3omb.macmonitor.telemetry.storage.io")
+        
+        let sample = try provider.sampleTelemetry()
+        XCTAssertNotNil(sample)
+        XCTAssertNotNil(sample["totalReadBytesPerSec"])
+        XCTAssertNotNil(sample["totalWriteBytesPerSec"])
+        XCTAssertNotNil(sample["disks"])
+    }
+}

Tests/MMKernelTelemetryTests.swift

@@ -0,0 +1,70 @@
+import XCTest
+@testable import MacMonitor
+
+final class MMKernelTelemetryTests: XCTestCase {
+    
+    func testKernelRatesCalculation() {
+        let prev: [String: NSNumber] = [
+            "contextSwitches": NSNumber(value: 100_000),
+            "syscalls": NSNumber(value: 200_000),
+            "pageFaults": NSNumber(value: 50_000),
+            "cowFaults": NSNumber(value: 1_000),
+            "zeroFills": NSNumber(value: 10_000),
+            "pageins": NSNumber(value: 500),
+            "pageouts": NSNumber(value: 100),
+            "decompressions": NSNumber(value: 200),
+            "compressions": NSNumber(value: 300)
+        ]
+        
+        let curr: [String: NSNumber] = [
+            "contextSwitches": NSNumber(value: 102_500), // delta = 2,500
+            "syscalls": NSNumber(value: 210_000),        // delta = 10,000
+            "pageFaults": NSNumber(value: 51_000),       // delta = 1,000
+            "cowFaults": NSNumber(value: 1_050),         // delta = 50
+            "zeroFills": NSNumber(value: 10_200),        // delta = 200
+            "pageins": NSNumber(value: 520),             // delta = 20
+            "pageouts": NSNumber(value: 105),            // delta = 5
+            "decompressions": NSNumber(value: 210),      // delta = 10
+            "compressions": NSNumber(value: 315)         // delta = 15
+        ]
+        
+        let timeDelta: TimeInterval = 2.0 // 2 seconds
+        
+        let rates = MMKernelTelemetryProvider.calculateRates(
+            withCurrentCounters: curr,
+            previousCounters: prev,
+            timeDelta: timeDelta
+        )
+        
+        let cswRate = rates["contextSwitchesRate"] as? Double ?? 0
+        let syscallRate = rates["syscallsRate"] as? Double ?? 0
+        let faultRate = rates["pageFaultsRate"] as? Double ?? 0
+        let cowRate = rates["cowFaultsRate"] as? Double ?? 0
+        let zeroFillRate = rates["zeroFillsRate"] as? Double ?? 0
+        let pageinsRate = rates["pageinsRate"] as? Double ?? 0
+        
+        XCTAssertEqual(cswRate, 1250.0, accuracy: 0.1)
+        XCTAssertEqual(syscallRate, 5000.0, accuracy: 0.1)
+        XCTAssertEqual(faultRate, 500.0, accuracy: 0.1)
+        XCTAssertEqual(cowRate, 25.0, accuracy: 0.1)
+        XCTAssertEqual(zeroFillRate, 100.0, accuracy: 0.1)
+        XCTAssertEqual(pageinsRate, 10.0, accuracy: 0.1)
+        
+        let cumCSW = rates["cumulative_contextSwitches"] as? UInt64 ?? 0
+        XCTAssertEqual(cumCSW, 102_500)
+    }
+    
+    func testLiveKernelProvider() throws {
+        let provider = MMKernelTelemetryProvider()
+        XCTAssertEqual(provider.domain, .system)
+        XCTAssertEqual(provider.providerIdentifier, "com.i3omb.macmonitor.telemetry.kernel.counters")
+        
+        let sample = try provider.sampleTelemetry()
+        XCTAssertNotNil(sample)
+        XCTAssertNotNil(sample["cumulative_contextSwitches"])
+        XCTAssertNotNil(sample["cumulative_syscalls"])
+        XCTAssertNotNil(sample["cumulative_pageFaults"])
+        XCTAssertNotNil(sample["contextSwitchesRate"])
+        XCTAssertNotNil(sample["syscallsRate"])
+    }
+}

Tests/MMLoadAverageTests.swift

@@ -0,0 +1,62 @@
+import XCTest
+@testable import MacMonitor
+
+final class MMLoadAverageTests: XCTestCase {
+    
+    func testLoadMetricsCalculation() {
+        let metrics = MMLoadAverageProvider.calculateLoadMetrics(
+            withLoad1: 4.0,
+            load5: 3.5,
+            load15: 2.5,
+            taskCount: 500,
+            threadCount: 2200,
+            cpuCount: 8,
+            machFactor: 1.25
+        )
+        
+        let load1 = metrics["load1m"] as? Double ?? 0
+        let norm1 = metrics["normalizedLoad1m"] as? Double ?? 0
+        let norm5 = metrics["normalizedLoad5m"] as? Double ?? 0
+        let taskCount = metrics["taskCount"] as? Int ?? 0
+        let threadCount = metrics["threadCount"] as? Int ?? 0
+        let isOverloaded = metrics["isOverloaded"] as? Bool ?? true
+        
+        XCTAssertEqual(load1, 4.0, accuracy: 0.01)
+        XCTAssertEqual(norm1, 4.0 / 8.0, accuracy: 0.01)
+        XCTAssertEqual(norm5, 3.5 / 8.0, accuracy: 0.01)
+        XCTAssertEqual(taskCount, 500)
+        XCTAssertEqual(threadCount, 2200)
+        XCTAssertFalse(isOverloaded)
+    }
+    
+    func testOverloadedStateDetection() {
+        let metrics = MMLoadAverageProvider.calculateLoadMetrics(
+            withLoad1: 12.0,
+            load5: 10.0,
+            load15: 8.0,
+            taskCount: 650,
+            threadCount: 3100,
+            cpuCount: 8,
+            machFactor: 0.4
+        )
+        
+        let isOverloaded = metrics["isOverloaded"] as? Bool ?? false
+        let norm1 = metrics["normalizedLoad1m"] as? Double ?? 0
+        
+        XCTAssertTrue(isOverloaded)
+        XCTAssertEqual(norm1, 1.5, accuracy: 0.01)
+    }
+    
+    func testLiveLoadAverageProvider() throws {
+        let provider = MMLoadAverageProvider()
+        XCTAssertEqual(provider.domain, .system)
+        XCTAssertEqual(provider.providerIdentifier, "com.i3omb.macmonitor.telemetry.system.load")
+        
+        let sample = try provider.sampleTelemetry()
+        XCTAssertNotNil(sample)
+        XCTAssertNotNil(sample["load1m"])
+        XCTAssertNotNil(sample["taskCount"])
+        XCTAssertNotNil(sample["threadCount"])
+        XCTAssertNotNil(sample["normalizedLoad1m"])
+    }
+}