Add support for context-aware logging functions

Summary:
@public

Context-aware logging functions are an internal Yoga feature that will be used for Yoga’s JNI code.

It will be possible to specify a context when calculating layout, which will be passed on to baseline and measure functions. This will be a private feature.

Reviewed By: SidharthGuglani

Differential Revision: D14123482

fbshipit-source-id: 8ba3b6c493bf79fe09831f22d2b6da44f09e3d95

java/jni/YGJNI.cpp

@@ -56,6 +56,7 @@ static void YGTransferLayoutOutputsRecursive(YGNodeRef root) {
     Log::log(
         root,
         YGLogLevelError,
+        nullptr,
         "Java YGNode was GCed during layout calculation\n");
     return;
   }
@@ -159,6 +160,7 @@ static void YGPrint(YGNodeRef node) {
     Log::log(
         node,
         YGLogLevelError,
+        nullptr,
         "Java YGNode was GCed during layout calculation\n");
   }
 }
@@ -245,6 +247,7 @@ static YGSize YGJNIMeasureFunc(
     Log::log(
         node,
         YGLogLevelError,
+        nullptr,
         "Java YGNode was GCed during layout calculation\n");
     return YGSize{
         widthMode == YGMeasureModeUndefined ? 0 : width,

yoga/YGConfig.cpp

@@ -6,13 +6,21 @@
  */
 #include "YGConfig.h"
 
-YGConfig::YGConfig(YGLogger logger) : logger_{logger} {}
+YGConfig::YGConfig(YGLogger logger) {
+  logger_.noContext = logger;
+  loggerUsesContext_ = false;
+}
 
 void YGConfig::log(
     YGConfig* config,
     YGNode* node,
     YGLogLevel logLevel,
+    void* logContext,
     const char* format,
     va_list args) {
-  logger_(config, node, logLevel, format, args);
+  if (loggerUsesContext_) {
+    logger_.withContext(config, node, logLevel, logContext, format, args);
+  } else {
+    logger_.noContext(config, node, logLevel, format, args);
+  }
 }

yoga/YGConfig.h

@@ -10,8 +10,20 @@
 #include "Yoga.h"
 
 struct YGConfig {
+  using LogWithContextFn = void (*)(
+      YGConfigRef config,
+      YGNodeRef node,
+      YGLogLevel level,
+      void* context,
+      const char* format,
+      va_list args);
+
 private:
-  YGLogger logger_;
+  union {
+    LogWithContextFn withContext;
+    YGLogger noContext;
+  } logger_;
+  bool loggerUsesContext_;
 
 public:
   bool useWebDefaults = false;
@@ -26,8 +38,16 @@ public:
   YGMarkerCallbacks markerCallbacks = {nullptr, nullptr};
 
   YGConfig(YGLogger logger);
-  void log(YGConfig*, YGNode*, YGLogLevel, const char*, va_list);
+  void log(YGConfig*, YGNode*, YGLogLevel, void*, const char*, va_list);
   void setLogger(YGLogger logger) {
-    logger_ = logger;
+    logger_.noContext = logger;
+    loggerUsesContext_ = false;
+  }
+  void setLogger(LogWithContextFn logger) {
+    logger_.withContext = logger;
+    loggerUsesContext_ = true;
+  }
+  void setLogger(std::nullptr_t) {
+    setLogger(YGLogger{nullptr});
   }
 };

yoga/Yoga.cpp

@@ -1030,7 +1030,7 @@ static void YGNodePrintInternal(
     const YGPrintOptions options) {
   std::string str;
   facebook::yoga::YGNodeToString(str, node, options, 0);
-  Log::log(node, YGLogLevelDebug, str.c_str());
+  Log::log(node, YGLogLevelDebug, nullptr, str.c_str());
 }
 
 void YGNodePrint(const YGNodeRef node, const YGPrintOptions options) {
@@ -3819,6 +3819,7 @@ bool YGLayoutNodeInternal(
       Log::log(
           node,
           YGLogLevelVerbose,
+          nullptr,
           "%s%d.{[skipped] ",
           YGSpacer(gDepth),
           gDepth);
@@ -3828,6 +3829,7 @@ bool YGLayoutNodeInternal(
       Log::log(
           node,
           YGLogLevelVerbose,
+          nullptr,
           "wm: %s, hm: %s, aw: %f ah: %f => d: (%f, %f) %s\n",
           YGMeasureModeName(widthMeasureMode, performLayout),
           YGMeasureModeName(heightMeasureMode, performLayout),
@@ -3842,6 +3844,7 @@ bool YGLayoutNodeInternal(
       Log::log(
           node,
           YGLogLevelVerbose,
+          nullptr,
           "%s%d.{%s",
           YGSpacer(gDepth),
           gDepth,
@@ -3852,6 +3855,7 @@ bool YGLayoutNodeInternal(
       Log::log(
           node,
           YGLogLevelVerbose,
+          nullptr,
           "wm: %s, hm: %s, aw: %f ah: %f %s\n",
           YGMeasureModeName(widthMeasureMode, performLayout),
           YGMeasureModeName(heightMeasureMode, performLayout),
@@ -3877,6 +3881,7 @@ bool YGLayoutNodeInternal(
       Log::log(
           node,
           YGLogLevelVerbose,
+          nullptr,
           "%s%d.}%s",
           YGSpacer(gDepth),
           gDepth,
@@ -3887,6 +3892,7 @@ bool YGLayoutNodeInternal(
       Log::log(
           node,
           YGLogLevelVerbose,
+          nullptr,
           "wm: %s, hm: %s, d: (%f, %f) %s\n",
           YGMeasureModeName(widthMeasureMode, performLayout),
           YGMeasureModeName(heightMeasureMode, performLayout),
@@ -3905,7 +3911,7 @@ bool YGLayoutNodeInternal(
       }
       if (layout->nextCachedMeasurementsIndex == YG_MAX_CACHED_RESULT_COUNT) {
         if (gPrintChanges) {
-          Log::log(node, YGLogLevelVerbose, "Out of cache entries!\n");
+          Log::log(node, YGLogLevelVerbose, nullptr, "Out of cache entries!\n");
         }
         layout->nextCachedMeasurementsIndex = 0;
       }
@@ -4200,7 +4206,7 @@ void YGConfigSetShouldDiffLayoutWithoutLegacyStretchBehaviour(
 
 void YGAssert(const bool condition, const char* message) {
   if (!condition) {
-    Log::log(YGNodeRef{nullptr}, YGLogLevelFatal, "%s\n", message);
+    Log::log(YGNodeRef{nullptr}, YGLogLevelFatal, nullptr, "%s\n", message);
   }
 }
 
@@ -4209,7 +4215,7 @@ void YGAssertWithNode(
     const bool condition,
     const char* message) {
   if (!condition) {
-    Log::log(node, YGLogLevelFatal, "%s\n", message);
+    Log::log(node, YGLogLevelFatal, nullptr, "%s\n", message);
   }
 }
 
@@ -4218,7 +4224,7 @@ void YGAssertWithConfig(
     const bool condition,
     const char* message) {
   if (!condition) {
-    Log::log(config, YGLogLevelFatal, "%s\n", message);
+    Log::log(config, YGLogLevelFatal, nullptr, "%s\n", message);
   }
 }
 

yoga/log.cpp

@@ -21,10 +21,11 @@ void vlog(
     YGConfig* config,
     YGNode* node,
     YGLogLevel level,
+    void* context,
     const char* format,
     va_list args) {
   YGConfig* logConfig = config != nullptr ? config : YGConfigGetDefault();
-  logConfig->log(logConfig, node, level, format, args);
+  logConfig->log(logConfig, node, level, context, format, args);
 
   if (level == YGLogLevelFatal) {
     abort();
@@ -35,23 +36,30 @@ void vlog(
 void Log::log(
     YGNode* node,
     YGLogLevel level,
+    void* context,
     const char* format,
     ...) noexcept {
   va_list args;
   va_start(args, format);
   vlog(
-      node == nullptr ? nullptr : node->getConfig(), node, level, format, args);
+      node == nullptr ? nullptr : node->getConfig(),
+      node,
+      level,
+      context,
+      format,
+      args);
   va_end(args);
 }
 
 void Log::log(
     YGConfig* config,
     YGLogLevel level,
+    void* context,
     const char* format,
     ...) noexcept {
   va_list args;
   va_start(args, format);
-  vlog(config, nullptr, level, format, args);
+  vlog(config, nullptr, level, context, format, args);
   va_end(args);
 }
 

yoga/log.h

@@ -20,12 +20,14 @@ struct Log {
   static void log(
       YGNode* node,
       YGLogLevel level,
+      void*,
       const char* message,
       ...) noexcept;
 
   static void log(
       YGConfig* config,
       YGLogLevel level,
+      void*,
       const char* format,
       ...) noexcept;
 };