QMUIRuntime 增加 qmui_getProjectClassList() 函数，优化 App 启动时寻找配置表的性能

BestKai · Dec 11, 2019 · c53f0a9 · c53f0a9
1 parent f9f872e
commit c53f0a9
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Showing 3 changed files with 82 additions and 20 deletions.
diff --git a/QMUIKit/QMUICore/QMUIConfiguration.m b/QMUIKit/QMUICore/QMUIConfiguration.m
@@ -83,29 +83,25 @@ - (void)applyInitialTemplate {
     // Automatically look for templates and apply them
     // @see https://github.com/Tencent/QMUI_iOS/issues/264
     Protocol *protocol = @protocol(QMUIConfigurationTemplateProtocol);
-    int numberOfClasses = objc_getClassList(NULL, 0);
-    if (numberOfClasses > 0) {
-        Class *classes = (__unsafe_unretained Class *)malloc(sizeof(Class) * numberOfClasses);
-        numberOfClasses = objc_getClassList(classes, numberOfClasses);
-        for (int i = 0; i < numberOfClasses; i++) {
-            Class class = classes[i];
-            // 这里用 containsString 是考虑到 Swift 里 className 由“项目前缀+class 名”组成，如果用 hasPrefix 就无法判断了
-            // Use `containsString` instead of `hasPrefix` because class names in Swift have project prefix prepended
-            if ([NSStringFromClass(class) containsString:@"QMUIConfigurationTemplate"] && [class conformsToProtocol:protocol]) {
-                if ([class instancesRespondToSelector:@selector(shouldApplyTemplateAutomatically)]) {
-                    id<QMUIConfigurationTemplateProtocol> template = [[class alloc] init];
-                    if ([template shouldApplyTemplateAutomatically]) {
-                        QMUI_hasAppliedInitialTemplate = YES;
-                        [template applyConfigurationTemplate];
-                        _active = YES;// 标志配置表已生效
-                        // 只应用第一个 shouldApplyTemplateAutomatically 的主题
-                        // Only apply the first template returned
-                        break;
-                    }
+    classref_t *classes = nil;
+    int numberOfClasses = qmui_getProjectClassList(&classes);
+    for (NSInteger i = 0; i < numberOfClasses; i++) {
+        Class class = (__bridge Class)classes[i];
+        // 这里用 containsString 是考虑到 Swift 里 className 由“项目前缀+class 名”组成，如果用 hasPrefix 就无法判断了
+        // Use `containsString` instead of `hasPrefix` because class names in Swift have project prefix prepended
+        if ([NSStringFromClass(class) containsString:@"QMUIConfigurationTemplate"] && [class conformsToProtocol:protocol]) {
+            if ([class instancesRespondToSelector:@selector(shouldApplyTemplateAutomatically)]) {
+                id<QMUIConfigurationTemplateProtocol> template = [[class alloc] init];
+                if ([template shouldApplyTemplateAutomatically]) {
+                    QMUI_hasAppliedInitialTemplate = YES;
+                    [template applyConfigurationTemplate];
+                    _active = YES;// 标志配置表已生效
+                    // 只应用第一个 shouldApplyTemplateAutomatically 的主题
+                    // Only apply the first template returned
+                    break;
                 }
             }
         }
-        free(classes);
     }
 
     if (IS_DEBUG && self.sendAnalyticsToQMUITeam) {

diff --git a/QMUIKit/QMUICore/QMUIRuntime.h b/QMUIKit/QMUICore/QMUIRuntime.h
@@ -318,3 +318,23 @@ _QMUIGetIvarValueGenerator(Selector, SEL)
 CG_INLINE id getObjectIvarValue(id object, Ivar ivar) {
     return object_getIvar(object, ivar);
 }
+
+
+#pragma mark - Mach-O
+
+typedef struct classref *classref_t;
+
+/**
+ 获取业务项目的所有 class
+ @param classes 传入 classref_t 变量的指针，会填充结果到里面，然后可以用下标访问。如果只是为了得到总数，可传入 NULL。
+ @return class 的总数
+ 
+ 例如：
+ 
+ @code
+ classref_t *classes = nil;
+ int count = qmui_getProjectClassList(&classes);
+ Class class = (__bridge Class)classes[0];
+ @endcode
+ */
+FOUNDATION_EXPORT int qmui_getProjectClassList(classref_t **classes);
diff --git a/QMUIKit/QMUICore/QMUIRuntime.m b/QMUIKit/QMUICore/QMUIRuntime.m
@@ -15,6 +15,8 @@
 
 #import "QMUIRuntime.h"
 #import "QMUICommonDefines.h"
+#include <mach-o/getsect.h>
+#include <mach-o/dyld.h>
 
 @implementation QMUIPropertyDescriptor
 
@@ -146,3 +148,47 @@ + (NSString *)typeWithEncodeString:(NSString *)encodeString {
 }
 
 @end
+
+#ifndef __LP64__
+typedef struct mach_header headerType;
+#else
+typedef struct mach_header_64 headerType;
+#endif
+
+static const headerType *getProjectImageHeader() {
+    const uint32_t imageCount = _dyld_image_count();
+    const char *target_image_name = ((NSString *)[[NSBundle mainBundle] objectForInfoDictionaryKey:(NSString *)kCFBundleExecutableKey]).UTF8String;
+    const headerType *target_image_header = 0;
+    for (uint32_t i = 0; i < imageCount; i++) {
+        const char *image_name = _dyld_get_image_name(i);
+        if (strstr(image_name, target_image_name) != NULL) {
+            target_image_header = (headerType *)_dyld_get_image_header(i);
+            break;
+        }
+    }
+    return target_image_header;
+}
+
+// from https://github.com/opensource-apple/objc4/blob/master/runtime/objc-file.mm
+static classref_t *getDataSection(const headerType *machHeader, const char *sectname, size_t *outCount) {
+    unsigned long byteCount = 0;
+    classref_t *data = (classref_t *)getsectiondata(machHeader, "__DATA", sectname, &byteCount);
+    if (!data) {
+        data = (classref_t *)getsectiondata(machHeader, "__DATA_CONST", sectname, &byteCount);
+    }
+    if (!data) {
+        data = (classref_t *)getsectiondata(machHeader, "__DATA_DIRTY", sectname, &byteCount);
+    }
+    if (outCount) *outCount = byteCount / sizeof(classref_t);
+    return data;
+}
+
+int qmui_getProjectClassList(classref_t **classes) {
+    size_t count = 0;
+    if (!classes) {
+        getDataSection(getProjectImageHeader(), "__objc_classlist", &count);
+        return (int)count;
+    }
+    *classes = getDataSection(getProjectImageHeader(), "__objc_classlist", &count);
+    return (int)count;
+}