Bug 805915 (part 4) - Add more detail to string memory reports. r=luke.

--HG--
extra : rebase_source : 010e28f10917ae4cc9d0d11abace9bcdabf0aba8

js/public/MemoryMetrics.h

@@ -134,7 +134,8 @@ struct CompartmentStats
       , gcHeapObjectsDenseArray(0)
       , gcHeapObjectsSlowArray(0)
       , gcHeapObjectsCrossCompartmentWrapper(0)
-      , gcHeapStrings(0)
+      , gcHeapStringsNormal(0)
+      , gcHeapStringsShort(0)
       , gcHeapShapesTree(0)
       , gcHeapShapesDict(0)
       , gcHeapShapesBase(0)
@@ -148,7 +149,7 @@ struct CompartmentStats
       , objectElements(0)
       , objectMisc(0)
       , objectPrivate(0)
-      , nonHugeStringChars(0)
+      , stringCharsNonHuge(0)
       , shapesExtraTreeTables(0)
       , shapesExtraDictTables(0)
       , shapesExtraTreeShapeKids(0)
@@ -172,7 +173,8 @@ struct CompartmentStats
       , gcHeapObjectsDenseArray(other.gcHeapObjectsDenseArray)
       , gcHeapObjectsSlowArray(other.gcHeapObjectsSlowArray)
       , gcHeapObjectsCrossCompartmentWrapper(other.gcHeapObjectsCrossCompartmentWrapper)
-      , gcHeapStrings(other.gcHeapStrings)
+      , gcHeapStringsNormal(other.gcHeapStringsNormal)
+      , gcHeapStringsShort(other.gcHeapStringsShort)
       , gcHeapShapesTree(other.gcHeapShapesTree)
       , gcHeapShapesDict(other.gcHeapShapesDict)
       , gcHeapShapesBase(other.gcHeapShapesBase)
@@ -186,7 +188,7 @@ struct CompartmentStats
       , objectElements(other.objectElements)
       , objectMisc(other.objectMisc)
       , objectPrivate(other.objectPrivate)
-      , nonHugeStringChars(other.nonHugeStringChars)
+      , stringCharsNonHuge(other.stringCharsNonHuge)
       , shapesExtraTreeTables(other.shapesExtraTreeTables)
       , shapesExtraDictTables(other.shapesExtraDictTables)
       , shapesExtraTreeShapeKids(other.shapesExtraTreeShapeKids)
@@ -217,7 +219,8 @@ struct CompartmentStats
     size_t gcHeapObjectsDenseArray;
     size_t gcHeapObjectsSlowArray;
     size_t gcHeapObjectsCrossCompartmentWrapper;
-    size_t gcHeapStrings;
+    size_t gcHeapStringsNormal;
+    size_t gcHeapStringsShort;
     size_t gcHeapShapesTree;
     size_t gcHeapShapesDict;
     size_t gcHeapShapesBase;
@@ -232,7 +235,7 @@ struct CompartmentStats
     size_t objectElements;
     size_t objectMisc;
     size_t objectPrivate;
-    size_t nonHugeStringChars;
+    size_t stringCharsNonHuge;
     size_t shapesExtraTreeTables;
     size_t shapesExtraDictTables;
     size_t shapesExtraTreeShapeKids;
@@ -261,7 +264,8 @@ struct CompartmentStats
         ADD(gcHeapObjectsDenseArray);
         ADD(gcHeapObjectsSlowArray);
         ADD(gcHeapObjectsCrossCompartmentWrapper);
-        ADD(gcHeapStrings);
+        ADD(gcHeapStringsNormal);
+        ADD(gcHeapStringsShort);
         ADD(gcHeapShapesTree);
         ADD(gcHeapShapesDict);
         ADD(gcHeapShapesBase);
@@ -276,7 +280,7 @@ struct CompartmentStats
         ADD(objectElements);
         ADD(objectMisc);
         ADD(objectPrivate);
-        ADD(nonHugeStringChars);
+        ADD(stringCharsNonHuge);
         ADD(shapesExtraTreeTables);
         ADD(shapesExtraDictTables);
         ADD(shapesExtraTreeShapeKids);

js/src/jsmemorymetrics.cpp

@@ -59,7 +59,8 @@ CompartmentStats::gcHeapThingsSize()
     n += gcHeapObjectsDenseArray;
     n += gcHeapObjectsSlowArray;
     n += gcHeapObjectsCrossCompartmentWrapper;
-    n += gcHeapStrings;
+    n += gcHeapStringsNormal;
+    n += gcHeapStringsShort;
     n += gcHeapShapesTree;
     n += gcHeapShapesDict;
     n += gcHeapShapesBase;
@@ -173,19 +174,23 @@ StatsCellCallback(JSRuntime *rt, void *data, void *thing, JSGCTraceKind traceKin
     case JSTRACE_STRING:
     {
         JSString *str = static_cast<JSString *>(thing);
-        cStats->gcHeapStrings += thingSize;
 
         size_t strSize = str->sizeOfExcludingThis(rtStats->mallocSizeOf);
 
         // If we can't grow hugeStrings, let's just call this string non-huge.
         // We're probably about to OOM anyway.
         if (strSize >= HugeStringInfo::MinSize() && cStats->hugeStrings.growBy(1)) {
+            cStats->gcHeapStringsNormal += thingSize;
             HugeStringInfo &info = cStats->hugeStrings.back();
             info.length = str->length();
-            info.size = str->sizeOfExcludingThis(rtStats->mallocSizeOf);
+            info.size = strSize;
             PutEscapedString(info.buffer, sizeof(info.buffer), &str->asLinear(), 0);
+        } else if (str->isShort()) {
+            MOZ_ASSERT(strSize == 0);
+            cStats->gcHeapStringsShort += thingSize;
         } else {
-          cStats->nonHugeStringChars += strSize;
+            cStats->gcHeapStringsNormal += thingSize;
+            cStats->stringCharsNonHuge += strSize;
         }
         break;
     }

js/src/vm/String.cpp

@@ -17,7 +17,6 @@
 using namespace mozilla;
 using namespace js;
 
-#ifdef DEBUG
 bool
 JSString::isShort() const
 {
@@ -28,7 +27,6 @@ JSString::isShort() const
     JS_ASSERT_IF(is_short, isFlat());
     return is_short;
 }
-#endif
 
 bool
 JSString::isExternal() const

js/src/vm/String.h

@@ -348,6 +348,8 @@ class JSString : public js::gc::Cell
         return *(JSInlineString *)this;
     }
 
+    bool isShort() const;
+
     JS_ALWAYS_INLINE
     JSStableString &asStable() const {
         JS_ASSERT(!isInline());
@@ -416,7 +418,6 @@ class JSString : public js::gc::Cell
     static inline js::ThingRootKind rootKind() { return js::THING_ROOT_STRING; }
 
 #ifdef DEBUG
-    bool isShort() const;
     void dump();
     static void dumpChars(const jschar *s, size_t len);
     bool equals(const char *s);

js/xpconnect/src/XPCJSRuntime.cpp

@@ -1497,15 +1497,21 @@ ReportCompartmentStats(const JS::CompartmentStats &cStats,
                      "Memory on the garbage-collected JavaScript "
                      "heap that holds cross-compartment wrapper objects.");
 
-    CREPORT_GC_BYTES(cJSPathPrefix + NS_LITERAL_CSTRING("gc-heap/strings"),
-                     cStats.gcHeapStrings,
+    CREPORT_GC_BYTES(cJSPathPrefix + NS_LITERAL_CSTRING("gc-heap/strings/normal"),
+                     cStats.gcHeapStringsNormal,
                      "Memory on the garbage-collected JavaScript "
-                     "heap that holds string headers.  String headers contain "
+                     "heap that holds normal string headers.  String headers contain "
                      "various pieces of information about a string, but do not "
                      "contain (except in the case of very short strings) the "
                      "string characters;  characters in longer strings are "
                      "counted under 'gc-heap/string-chars' instead.");
 
+    CREPORT_GC_BYTES(cJSPathPrefix + NS_LITERAL_CSTRING("gc-heap/strings/short"),
+                     cStats.gcHeapStringsShort,
+                     "Memory on the garbage-collected JavaScript "
+                     "heap that holds over-sized string headers, in which "
+                     "string characters are stored inline.");
+
     CREPORT_GC_BYTES(cJSPathPrefix + NS_LITERAL_CSTRING("gc-heap/scripts"),
                      cStats.gcHeapScripts,
                      "Memory on the garbage-collected JavaScript "
@@ -1645,7 +1651,7 @@ ReportCompartmentStats(const JS::CompartmentStats &cStats,
                   "transient analysis information.  Cleared on GC.");
 
     CREPORT_BYTES2(cJSPathPrefix + NS_LITERAL_CSTRING("string-chars/non-huge"),
-                   cStats.nonHugeStringChars, nsPrintfCString(
+                   cStats.stringCharsNonHuge, nsPrintfCString(
                    "Memory allocated to hold characters of strings whose "
                    "characters take up less than than %d bytes of memory.\n\n"
                    "Sometimes more memory is allocated than necessary, to "