[PLAT-8749] Trim breadcrumbs in oversized payloads

Bugsnag/Delivery/BSGEventUploadOperation.m

@@ -76,12 +76,12 @@ - (void)runWithDelegate:(id<BSGEventUploadOperationDelegate>)delegate completion
         return;
     }
 
-    NSDictionary *_Nullable originalPayload = nil;
+    NSDictionary *retryPayload = nil;
     for (BugsnagOnSendErrorBlock block in configuration.onSendBlocks) {
         @try {
-            if (!originalPayload) {
+            if (!retryPayload) {
                 // If OnSendError modifies the event and delivery fails, we need to persist the original state of the event.
-                originalPayload = [event toJsonWithRedactedKeys:configuration.redactedKeys];
+                retryPayload = [event toJsonWithRedactedKeys:configuration.redactedKeys];
             }
             if (!block(event)) {
                 [self deleteEvent];
@@ -97,8 +97,11 @@ - (void)runWithDelegate:(id<BSGEventUploadOperationDelegate>)delegate completion
     @try {
         [event truncateStrings:configuration.maxStringValueLength];
         eventPayload = [event toJsonWithRedactedKeys:configuration.redactedKeys];
+        if (!retryPayload || [retryPayload isEqualToDictionary:eventPayload]) {
+            retryPayload = eventPayload;
+        }
     } @catch (NSException *exception) {
-        bsg_log_err(@"Discarding event %@ because an exception was thrown by -toJsonWithRedactedKeys: %@", self.name, exception);
+        bsg_log_err(@"Discarding event %@ due to exception %@", self.name, exception);
         [BSGInternalErrorReporter.sharedInstance reportException:exception diagnostics:nil groupingHash:
          [NSString stringWithFormat:@"BSGEventUploadOperation -[runWithDelegate:completionHandler:] %@ %@",
           exception.name, exception.reason]];
@@ -107,11 +110,6 @@ - (void)runWithDelegate:(id<BSGEventUploadOperationDelegate>)delegate completion
         return;
     }
 
-    if ([originalPayload isEqual:eventPayload]) {
-        // Save memory if payload has not changed
-        originalPayload = nil;
-    }
-
     NSString *apiKey = event.apiKey ?: configuration.apiKey;
 
     NSMutableDictionary *requestPayload = [NSMutableDictionary dictionary];
@@ -140,6 +138,26 @@ - (void)runWithDelegate:(id<BSGEventUploadOperationDelegate>)delegate completion
         return;
     }
 
+    if (data.length > MaxPersistedSize) {
+        // Trim extra bytes to make space for "removed" message and usage telemetry.
+        NSUInteger bytesToRemove = data.length - (MaxPersistedSize - 300);
+        bsg_log_debug(@"Trimming breadcrumbs; bytesToRemove = %lu", (unsigned long)bytesToRemove);
+        @try {
+            [event trimBreadcrumbs:bytesToRemove];
+            eventPayload = [event toJsonWithRedactedKeys:configuration.redactedKeys];
+            requestPayload[BSGKeyEvents] = @[eventPayload];
+            data = BSGJSONDataFromDictionary(requestPayload, NULL);
+        } @catch (NSException *exception) {
+            bsg_log_err(@"Discarding event %@ due to exception %@", self.name, exception);
+            [BSGInternalErrorReporter.sharedInstance reportException:exception diagnostics:nil groupingHash:
+             [NSString stringWithFormat:@"BSGEventUploadOperation -[runWithDelegate:completionHandler:] %@ %@",
+              exception.name, exception.reason]];
+            [self deleteEvent];
+            completionHandler();
+            return;
+        }
+    }
+
     BSGPostJSONData(configuration.session, data, requestHeaders, notifyURL, ^(BSGDeliveryStatus status, __unused NSError *deliveryError) {
         switch (status) {
             case BSGDeliveryStatusDelivered:
@@ -149,7 +167,7 @@ - (void)runWithDelegate:(id<BSGEventUploadOperationDelegate>)delegate completion
 
             case BSGDeliveryStatusFailed:
                 bsg_log_debug(@"Upload failed retryably for event %@", self.name);
-                [self prepareForRetry:originalPayload ?: eventPayload HTTPBodySize:data.length];
+                [self prepareForRetry:retryPayload HTTPBodySize:data.length];
                 break;
 
             case BSGDeliveryStatusUndeliverable:

Bugsnag/Payload/BugsnagEvent+Private.h

@@ -73,6 +73,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSDictionary *)toJsonWithRedactedKeys:(nullable NSSet *)redactedKeys;
 
+- (void)trimBreadcrumbs:(NSUInteger)bytesToRemove;
+
 - (void)truncateStrings:(NSUInteger)maxLength;
 
 - (void)notifyUnhandledOverridden;

Bugsnag/Payload/BugsnagEvent.m

@@ -10,6 +10,7 @@
 
 #import "BSGDefines.h"
 #import "BSGFeatureFlagStore.h"
+#import "BSGJSONSerialization.h"
 #import "BSGKeys.h"
 #import "BSGSerialization.h"
 #import "BSGUtils.h"
@@ -690,6 +691,41 @@ - (void)symbolicateIfNeeded {
     }
 }
 
+- (void)trimBreadcrumbs:(const NSUInteger)bytesToRemove {
+    NSMutableArray *breadcrumbs = [self.breadcrumbs mutableCopy];
+    BugsnagBreadcrumb *lastRemovedBreadcrumb = nil;
+    NSUInteger bytesRemoved = 0, count = 0;
+
+    while (bytesRemoved < bytesToRemove && breadcrumbs.count) {
+        lastRemovedBreadcrumb = [breadcrumbs firstObject];
+        [breadcrumbs removeObjectAtIndex:0];
+
+        NSDictionary *dict = [lastRemovedBreadcrumb objectValue];
+        NSData *data = BSGJSONDataFromDictionary(dict, NULL);
+        bytesRemoved += data.length;
+        count++;
+    }
+
+    if (lastRemovedBreadcrumb) {
+        lastRemovedBreadcrumb.message = count < 2 ? @"Removed to reduce payload size" :
+        [NSString stringWithFormat:@"Removed, along with %lu older breadcrumb%s, to reduce payload size",
+         (unsigned long)(count - 1), count == 2 ? "" : "s"];
+        lastRemovedBreadcrumb.metadata = @{};
+        [breadcrumbs insertObject:lastRemovedBreadcrumb atIndex:0];
+    }
+
+    self.breadcrumbs = breadcrumbs;
+
+    NSDictionary *usage = self.usage;
+    if (usage) {
+        self.usage = BSGDictMerge(@{
+            @"system": @{
+                @"breadcrumbBytesRemoved": @(bytesRemoved),
+                @"breadcrumbsRemoved": @(count)}
+        }, usage);
+    }
+}
+
 - (void)truncateStrings:(NSUInteger)maxLength {
     BSGTruncateContext context = {
         .maxLength = maxLength

CHANGELOG.md

@@ -5,6 +5,9 @@ Changelog
 
 ### Enhancements
 
+* Trim breadcrumb messages & metadata in payloads that exceed the size limit.
+  [#1451](https://github.com/bugsnag/bugsnag-cocoa/pull/1451)
+
 * Truncate breadcrumb and metadata strings that are longer than `configuration.maxStringValueLength`.
   [#1449](https://github.com/bugsnag/bugsnag-cocoa/pull/1449)
 

Tests/BugsnagTests/BugsnagEventTests.m

@@ -11,6 +11,7 @@
 
 #import "BSG_RFC3339DateTool.h"
 #import "Bugsnag.h"
+#import "BugsnagBreadcrumb+Private.h"
 #import "BugsnagClient+Private.h"
 #import "BugsnagEvent+Private.h"
 #import "BugsnagHandledState.h"
@@ -321,6 +322,66 @@ - (void)testJsonToEventToJson {
     }
 }
 
+- (void)testTrimBreadcrumbs {
+    BugsnagEvent *event = [BugsnagEvent new];
+
+    BugsnagBreadcrumb * (^ MakeBreadcrumb)() = ^(BSGBreadcrumbType type, NSString *message, NSDictionary *metadata) {
+        BugsnagBreadcrumb *breadcrumb = [BugsnagBreadcrumb new];
+        breadcrumb.type = type;
+        breadcrumb.message = message;
+        breadcrumb.metadata = metadata;
+        return breadcrumb;
+    };
+
+    event.breadcrumbs = @[
+        MakeBreadcrumb(BSGBreadcrumbTypeState, @"Test started", @{}), // 91 bytes
+        MakeBreadcrumb(BSGBreadcrumbTypeLog, @"Some log message", @{@"some": @"metadata"}), // 110 bytes
+        MakeBreadcrumb(BSGBreadcrumbTypeManual, @"The final breadcrumb", @{@"key": @"untouched"})];
+
+    event.usage = @{@"sentinel": @42}; // Enable gathering telemetry
+
+    [event trimBreadcrumbs:100];
+
+    XCTAssertEqual(event.breadcrumbs.count, 2);
+
+    XCTAssertEqual       (event.breadcrumbs[0].type, BSGBreadcrumbTypeLog);
+    XCTAssertEqualObjects(event.breadcrumbs[0].message, @"Removed, along with 1 older breadcrumb, to reduce payload size");
+    XCTAssertEqualObjects(event.breadcrumbs[0].metadata, @{});
+
+    XCTAssertEqual       (event.breadcrumbs[1].type, BSGBreadcrumbTypeManual);
+    XCTAssertEqualObjects(event.breadcrumbs[1].message, @"The final breadcrumb");
+    XCTAssertEqualObjects(event.breadcrumbs[1].metadata, @{@"key": @"untouched"});
+
+    XCTAssertEqualObjects(event.usage, (@{@"system": @{@"breadcrumbBytesRemoved": @(91 + 110), @"breadcrumbsRemoved": @2}, @"sentinel": @42}));
+}
+
+- (void)testTrimSingleBreadcrumbs {
+    BugsnagEvent *event = [BugsnagEvent new];
+
+    BugsnagBreadcrumb *breadcrumb = [BugsnagBreadcrumb new]; 
+    breadcrumb.message = @""
+    "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor i"
+    "ncididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostru"
+    "d exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aut"
+    "e irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat n"
+    "ulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui"
+    " officia deserunt mollit anim id est laborum.";
+    breadcrumb.metadata = @{@"something": @"👍🏾🔥"};
+    breadcrumb.type = BSGBreadcrumbTypeError;
+    event.breadcrumbs = @[breadcrumb];
+
+    NSUInteger byteCount = [NSJSONSerialization dataWithJSONObject:[breadcrumb objectValue] options:0 error:NULL].length; 
+
+    event.usage = @{}; // Enable gathering telemetry
+
+    [event trimBreadcrumbs:100];
+
+    XCTAssertEqual       (event.breadcrumbs[0].type, BSGBreadcrumbTypeError);
+    XCTAssertEqualObjects(event.breadcrumbs[0].message, @"Removed to reduce payload size");
+    XCTAssertEqualObjects(event.breadcrumbs[0].metadata, @{});
+    XCTAssertEqualObjects(event.usage, (@{@"system": @{@"breadcrumbBytesRemoved": @(byteCount), @"breadcrumbsRemoved": @1}}));
+}
+
 - (void)testTruncateStrings {
     BugsnagEvent *event = [BugsnagEvent new];
 

features/delivery.feature

@@ -142,3 +142,17 @@ Feature: Delivery of errors
     Then the session "user.id" equals "3"
     And I discard the oldest session
     And the session "user.id" equals "2"
+
+  Scenario: Breadcrumbs should be trimmed if payload is oversized
+    When I run "OversizedBreadcrumbsScenario"
+    And I wait to receive an error
+    Then the event "breadcrumbs" is an array with 10 elements
+    And the error "Content-Length" header matches the regex "^9\d{5}$"
+    And the event "breadcrumbs.0.metaData.a" is null
+    And the event "breadcrumbs.0.name" equals "Removed, along with 16 older breadcrumbs, to reduce payload size"
+    And the event "breadcrumbs.9.metaData.a" is not null
+    And the event "breadcrumbs.9.name" equals "Breadcrumb 25"
+    And the event "usage.system.breadcrumbBytesRemoved" equals 1602740
+    And the event "usage.system.breadcrumbsRemoved" equals 17
+    And the event "usage.system.stringCharsTruncated" is not null
+    And the event "usage.system.stringsTruncated" is not null

features/fixtures/ios/iOSTestApp.xcodeproj/project.pbxproj

@@ -61,6 +61,7 @@
 		01221E55282E5538008095C3 /* MaxPersistedSessionsScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 01221E54282E5538008095C3 /* MaxPersistedSessionsScenario.m */; };
 		0163BFA72583B3CF008DC28B /* DiscardClassesHandledExceptionRegexScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0163BFA62583B3CF008DC28B /* DiscardClassesHandledExceptionRegexScenario.swift */; };
 		017B4134276B8D9B0054C91D /* OnSendErrorPersistenceScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 017B4133276B8D9B0054C91D /* OnSendErrorPersistenceScenario.m */; };
+		017BA42428A1558A00CB985E /* OversizedBreadcrumbsScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 017BA42328A1558A00CB985E /* OversizedBreadcrumbsScenario.swift */; };
 		017DCFA028743FB5000ECB22 /* TelemetryUsageDisabledScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 017DCF9F28743FB5000ECB22 /* TelemetryUsageDisabledScenario.swift */; };
 		01847DD626453D4E00ADA4C7 /* InvalidCrashReportScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 01847DD526453D4E00ADA4C7 /* InvalidCrashReportScenario.m */; };
 		01AF6A53258A112F00FFC803 /* BareboneTestHandledScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01AF6A52258A112F00FFC803 /* BareboneTestHandledScenario.swift */; };
@@ -252,6 +253,7 @@
 		01221E54282E5538008095C3 /* MaxPersistedSessionsScenario.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MaxPersistedSessionsScenario.m; sourceTree = "<group>"; };
 		0163BFA62583B3CF008DC28B /* DiscardClassesHandledExceptionRegexScenario.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DiscardClassesHandledExceptionRegexScenario.swift; sourceTree = "<group>"; };
 		017B4133276B8D9B0054C91D /* OnSendErrorPersistenceScenario.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = OnSendErrorPersistenceScenario.m; sourceTree = "<group>"; };
+		017BA42328A1558A00CB985E /* OversizedBreadcrumbsScenario.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OversizedBreadcrumbsScenario.swift; sourceTree = "<group>"; };
 		017DCF9F28743FB5000ECB22 /* TelemetryUsageDisabledScenario.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TelemetryUsageDisabledScenario.swift; sourceTree = "<group>"; };
 		01847DD526453D4E00ADA4C7 /* InvalidCrashReportScenario.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = InvalidCrashReportScenario.m; sourceTree = "<group>"; };
 		01AF6A52258A112F00FFC803 /* BareboneTestHandledScenario.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BareboneTestHandledScenario.swift; sourceTree = "<group>"; };
@@ -579,6 +581,7 @@
 				010BAAFC2833CE570003FF36 /* OOMWillTerminateScenario.m */,
 				E700EE58247D321B008CFFB6 /* OriginalErrorNSErrorScenario.swift */,
 				E700EE5A247D3224008CFFB6 /* OriginalErrorNSExceptionScenario.swift */,
+				017BA42328A1558A00CB985E /* OversizedBreadcrumbsScenario.swift */,
 				01F6B75C2832757F00B75C5D /* OversizedCrashReportScenario.swift */,
 				01F6B75D2832757F00B75C5D /* OversizedHandledErrorScenario.swift */,
 				F4295B041F9CC494473DD226 /* OverwriteLinkRegisterScenario.m */,
@@ -745,6 +748,7 @@
 				010BAB252833D0070003FF36 /* AppHangDisabledScenario.swift in Sources */,
 				E75040A02478019D005D33BD /* AutoDetectFalseHandledScenario.swift in Sources */,
 				01F115C927BAAF2D00892B1E /* SIGPIPEIgnoredScenario.m in Sources */,
+				017BA42428A1558A00CB985E /* OversizedBreadcrumbsScenario.swift in Sources */,
 				8AB8866620404DD30003E444 /* ViewController.swift in Sources */,
 				010BAB0E2833CE570003FF36 /* UnhandledMachExceptionOverrideScenario.m in Sources */,
 				8AB8866420404DD30003E444 /* AppDelegate.swift in Sources */,

features/fixtures/macos/macOSTestApp.xcodeproj/project.pbxproj

@@ -68,6 +68,7 @@
 		01AFCFC7282C058D00D48D45 /* OldSessionScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 01AFCFC6282C058D00D48D45 /* OldSessionScenario.m */; };
 		01B6BB7225D56CBF00FC4DE6 /* LastRunInfoScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01B6BB7125D56CBF00FC4DE6 /* LastRunInfoScenario.swift */; };
 		01B6BBA225DA774C00FC4DE6 /* SendLaunchCrashesSynchronouslyScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01B6BBA125DA774C00FC4DE6 /* SendLaunchCrashesSynchronouslyScenario.swift */; };
+		01BB5D2628A1463C00A7F322 /* OversizedBreadcrumbsScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01BB5D2528A1463C00A7F322 /* OversizedBreadcrumbsScenario.swift */; };
 		01DCB82D279868160048640A /* ConcurrentCrashesScenario.mm in Sources */ = {isa = PBXBuildFile; fileRef = 01DCB82C279868160048640A /* ConcurrentCrashesScenario.mm */; };
 		01DE903A26CEAD1200455213 /* CriticalThermalStateScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01DE903926CEAD1200455213 /* CriticalThermalStateScenario.swift */; };
 		01E0DB0625E8E95700A740ED /* AppDurationScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01E0DB0425E8E90500A740ED /* AppDurationScenario.swift */; };
@@ -269,6 +270,7 @@
 		01AFCFC6282C058D00D48D45 /* OldSessionScenario.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = OldSessionScenario.m; sourceTree = "<group>"; };
 		01B6BB7125D56CBF00FC4DE6 /* LastRunInfoScenario.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LastRunInfoScenario.swift; sourceTree = "<group>"; };
 		01B6BBA125DA774C00FC4DE6 /* SendLaunchCrashesSynchronouslyScenario.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SendLaunchCrashesSynchronouslyScenario.swift; sourceTree = "<group>"; };
+		01BB5D2528A1463C00A7F322 /* OversizedBreadcrumbsScenario.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OversizedBreadcrumbsScenario.swift; sourceTree = "<group>"; };
 		01DCB82C279868160048640A /* ConcurrentCrashesScenario.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ConcurrentCrashesScenario.mm; sourceTree = "<group>"; };
 		01DE903926CEAD1200455213 /* CriticalThermalStateScenario.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CriticalThermalStateScenario.swift; sourceTree = "<group>"; };
 		01E0DB0425E8E90500A740ED /* AppDurationScenario.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDurationScenario.swift; sourceTree = "<group>"; };
@@ -530,6 +532,7 @@
 				01F47C97254B1B2F00B184AD /* OOMWillTerminateScenario.m */,
 				01F47C86254B1B2F00B184AD /* OriginalErrorNSErrorScenario.swift */,
 				01F47C21254B1B2C00B184AD /* OriginalErrorNSExceptionScenario.swift */,
+				01BB5D2528A1463C00A7F322 /* OversizedBreadcrumbsScenario.swift */,
 				01F6B74B2832381300B75C5D /* OversizedCrashReportScenario.swift */,
 				01F6B7492832381300B75C5D /* OversizedHandledErrorScenario.swift */,
 				01F47CC0254B1B3000B184AD /* OverwriteLinkRegisterScenario.m */,
@@ -938,6 +941,7 @@
 				010BAB672833D34A0003FF36 /* HandledErrorValidReleaseStageScenario.swift in Sources */,
 				01F47CD1254B1B3100B184AD /* ManualContextClientScenario.swift in Sources */,
 				010BAB732833D34A0003FF36 /* AppAndDeviceAttributesStartWithApiKeyScenario.swift in Sources */,
+				01BB5D2628A1463C00A7F322 /* OversizedBreadcrumbsScenario.swift in Sources */,
 				01F47CC9254B1B3100B184AD /* BuiltinTrapScenario.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

features/fixtures/shared/scenarios/OversizedBreadcrumbsScenario.swift

@@ -0,0 +1,16 @@
+class OversizedBreadcrumbsScenario: Scenario {
+
+    override func run() {
+
+        var metadata: [String: String] = [:]
+        for char in "abcdefghij" {
+            metadata["\(char)"] = String(repeating: ".", count: 10_000)
+        }
+
+        for i in 1...25 {
+            Bugsnag.leaveBreadcrumb("Breadcrumb \(i)", metadata: metadata, type: .navigation)
+        }
+
+        Bugsnag.notifyError(NSError(domain: NSCocoaErrorDomain, code: NSFileNoSuchFileError))
+    }
+}