From 77572bdaec82f234b785fb5a470294affebf9dfc Mon Sep 17 00:00:00 2001
From: Matthew Chen <charlesmchen@gmail.com>
Date: Wed, 10 Jan 2018 12:36:23 -0500
Subject: [PATCH] Retain changes from session database branch.

---
 SignalServiceKit/src/Util/OWSAsserts.h | 127 +++++++++++++++++++++++++
 SignalServiceKit/src/Util/OWSAsserts.m |  14 +++
 2 files changed, 141 insertions(+)
 create mode 100755 SignalServiceKit/src/Util/OWSAsserts.h
 create mode 100755 SignalServiceKit/src/Util/OWSAsserts.m

diff --git a/SignalServiceKit/src/Util/OWSAsserts.h b/SignalServiceKit/src/Util/OWSAsserts.h
new file mode 100755
index 000000000..c417c12b6
--- /dev/null
+++ b/SignalServiceKit/src/Util/OWSAsserts.h
@@ -0,0 +1,127 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+NS_ASSUME_NONNULL_BEGIN
+
+#ifndef OWSAssert
+
+#ifdef DEBUG
+
+#define USE_ASSERTS
+
+#define CONVERT_TO_STRING(X) #X
+#define CONVERT_EXPR_TO_STRING(X) CONVERT_TO_STRING(X)
+
+// OWSAssert() and OWSFail() should be used in Obj-C methods.
+// OWSCAssert() and OWSCFail() should be used in free functions.
+
+#define OWSAssert(X)                                                                                                   \
+    if (!(X)) {                                                                                                        \
+        DDLogError(@"%s Assertion failed: %s", __PRETTY_FUNCTION__, CONVERT_EXPR_TO_STRING(X));                        \
+        [DDLog flushLog];                                                                                              \
+        NSAssert(0, @"Assertion failed: %s", CONVERT_EXPR_TO_STRING(X));                                               \
+    }
+
+#define OWSCAssert(X)                                                                                                  \
+    if (!(X)) {                                                                                                        \
+        DDLogError(@"%s Assertion failed: %s", __PRETTY_FUNCTION__, CONVERT_EXPR_TO_STRING(X));                        \
+        [DDLog flushLog];                                                                                              \
+        NSCAssert(0, @"Assertion failed: %s", CONVERT_EXPR_TO_STRING(X));                                              \
+    }
+
+#define OWSFail(message, ...)                                                                                          \
+    {                                                                                                                  \
+        NSString *formattedMessage = [NSString stringWithFormat:message, ##__VA_ARGS__];                               \
+        DDLogError(@"%s %@", __PRETTY_FUNCTION__, formattedMessage);                                                   \
+        [DDLog flushLog];                                                                                              \
+        NSAssert(0, formattedMessage);                                                                                 \
+    }
+
+#define OWSCFail(message, ...)                                                                                         \
+    {                                                                                                                  \
+        NSString *formattedMessage = [NSString stringWithFormat:message, ##__VA_ARGS__];                               \
+        DDLogError(@"%s %@", __PRETTY_FUNCTION__, formattedMessage);                                                   \
+        [DDLog flushLog];                                                                                              \
+        NSCAssert(0, formattedMessage);                                                                                \
+    }
+
+#define OWSFailNoFormat(message)                                                                                       \
+    {                                                                                                                  \
+        DDLogError(@"%s %@", __PRETTY_FUNCTION__, message);                                                            \
+        [DDLog flushLog];                                                                                              \
+        NSAssert(0, message);                                                                                          \
+    }
+
+#define OWSCFailNoFormat(message)                                                                                      \
+    {                                                                                                                  \
+        DDLogError(@"%s %@", __PRETTY_FUNCTION__, message);                                                            \
+        [DDLog flushLog];                                                                                              \
+        NSCAssert(0, message);                                                                                         \
+    }
+
+#else
+
+#define OWSAssert(X)
+#define OWSCAssert(X)
+#define OWSFail(message, ...)
+#define OWSCFail(message, ...)
+#define OWSFailNoFormat(X)
+#define OWSCFailNoFormat(X)
+
+#endif
+
+#endif
+
+#define OWS_ABSTRACT_METHOD() OWSFail(@"Method needs to be implemented by subclasses.")
+
+#pragma mark - Singleton Asserts
+
+// The "singleton asserts" can be used to ensure
+// that we only create a singleton once.
+//
+// The simplest way to use them is the OWSSingletonAssert() macro.
+// It is intended to be used inside the singleton's initializer.
+//
+// If, however, a singleton has multiple possible initializers,
+// you need to:
+//
+// 1. Use OWSSingletonAssertFlag() outside the class definition.
+// 2. Use OWSSingletonAssertInit() in each initializer.
+
+#ifndef SSK_BUILDING_FOR_TESTS
+#ifdef DEBUG
+
+#define ENFORCE_SINGLETONS
+
+#endif
+#endif
+
+#ifdef ENFORCE_SINGLETONS
+
+#define OWSSingletonAssertFlag() static BOOL _isSingletonCreated = NO;
+
+#define OWSSingletonAssertInit()                                                                                       \
+    @synchronized([self class])                                                                                        \
+    {                                                                                                                  \
+        OWSAssert(!_isSingletonCreated);                                                                               \
+        _isSingletonCreated = YES;                                                                                     \
+    }
+
+#define OWSSingletonAssert() OWSSingletonAssertFlag() OWSSingletonAssertInit()
+
+#else
+
+#define OWSSingletonAssertFlag()
+#define OWSSingletonAssertInit()
+#define OWSSingletonAssert()
+
+#endif
+
+// This macro is intended for use in Objective-C.
+#define OWSAssertIsOnMainThread() OWSCAssert([NSThread isMainThread])
+
+// This function is intended for use in Swift.
+void AssertIsOnMainThread(void);
+
+NS_ASSUME_NONNULL_END
diff --git a/SignalServiceKit/src/Util/OWSAsserts.m b/SignalServiceKit/src/Util/OWSAsserts.m
new file mode 100755
index 000000000..df97c17ab
--- /dev/null
+++ b/SignalServiceKit/src/Util/OWSAsserts.m
@@ -0,0 +1,14 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+#import "OWSAsserts.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+void AssertIsOnMainThread()
+{
+    OWSCAssert([NSThread isMainThread]);
+}
+
+NS_ASSUME_NONNULL_END