Add support for light dumps in SkTraceMemoryDump interface.

SkGlyphCache dumps too many glyphs, and to reduce the trace size,
RequestDetails enum is added to SkTraceMemoryDump interface. This
would tell caches to dump only requested details or not a detailed
dump.

BUG=499731

Review URL: https://codereview.chromium.org/1310123007

4 files changed, 42 insertions, 11 deletions

diff --git a/include/core/SkTraceMemoryDump.h b/include/core/SkTraceMemoryDump.h
index d7c565f570..8383190ccc 100644
--- a/include/core/SkTraceMemoryDump.h
+++ b/include/core/SkTraceMemoryDump.h
@@ -20,6 +20,17 @@ class SkDiscardableMemory;
 class SK_API SkTraceMemoryDump {
 public:
     /**
+     * Enum to specify the level of the requested details for the dump from the Skia objects.
+     */
+    enum LevelOfDetail {
+        // Dump only the minimal details to get the total memory usage (Usually just the totals).
+        kLight_LevelOfDetail,
+
+        // Dump the detailed breakdown of the objects in the caches.
+        kObjectsBreakdowns_LevelOfDetail
+    };
+
+    /**
      *  Appends a new memory dump (i.e. a row) to the trace memory infrastructure.
      *  If dumpName does not exist yet, a new one is created. Otherwise, a new column is appended to
      *  the previously created dump.
@@ -55,6 +66,13 @@ public:
         const char* dumpName,
         const SkDiscardableMemory& discardableMemoryObject) = 0;
 
+    /**
+     * Returns the type of details requested in the dump. The granularity of the dump is supposed to
+     * match the LevelOfDetail argument. The level of detail must not affect the total size
+     * reported, but only granularity of the child entries.
+     */
+    virtual LevelOfDetail getRequestedDetails() const = 0;
+
 protected:
     virtual ~SkTraceMemoryDump() { }
 };
diff --git a/src/core/SkGlyphCache.cpp b/src/core/SkGlyphCache.cpp
index 9bee4e5f75..3f64d6ed48 100644
--- a/src/core/SkGlyphCache.cpp
+++ b/src/core/SkGlyphCache.cpp
@@ -427,16 +427,16 @@ static void sk_trace_dump_visitor(const SkGlyphCache& cache, void* context) {
     *counter += 1;
 
     const SkTypeface* face = cache.getScalerContext()->getTypeface();
-    SkString font_name;
-    face->getFamilyName(&font_name);
+    SkString fontName;
+    face->getFamilyName(&fontName);
     const SkScalerContextRec& rec = cache.getScalerContext()->getRec();
 
-    SkString dump_name = SkStringPrintf("%s/%s_%3d/index_%d",
-                                        gGlyphCacheDumpName, font_name.c_str(), rec.fFontID, index);
+    SkString dumpName = SkStringPrintf("%s/%s_%3d/index_%d",
+                                        gGlyphCacheDumpName, fontName.c_str(), rec.fFontID, index);
 
-    dump->dumpNumericValue(dump_name.c_str(), "size", "bytes", cache.getMemoryUsed());
-    dump->dumpNumericValue(dump_name.c_str(), "glyph_count", "objects", cache.countCachedGlyphs());
-    dump->setMemoryBacking(dump_name.c_str(), "malloc", nullptr);
+    dump->dumpNumericValue(dumpName.c_str(), "size", "bytes", cache.getMemoryUsed());
+    dump->dumpNumericValue(dumpName.c_str(), "glyph_count", "objects", cache.countCachedGlyphs());
+    dump->setMemoryBacking(dumpName.c_str(), "malloc", nullptr);
 }
 
 void SkGlyphCache::DumpMemoryStatistics(SkTraceMemoryDump* dump) {
@@ -448,6 +448,11 @@ void SkGlyphCache::DumpMemoryStatistics(SkTraceMemoryDump* dump) {
     dump->dumpNumericValue(gGlyphCacheDumpName, "budget_glyph_count", "objects",
                            SkGraphics::GetFontCacheCountLimit());
 
+    if (dump->getRequestedDetails() == SkTraceMemoryDump::kLight_LevelOfDetail) {
+        dump->setMemoryBacking(gGlyphCacheDumpName, "malloc", nullptr);
+        return;
+    }
+
     int counter = 0;
     SkGlyphCacheDumpContext context = { &counter, dump };
     SkGlyphCache::VisitAll(sk_trace_dump_visitor, &context);
diff --git a/src/core/SkResourceCache.cpp b/src/core/SkResourceCache.cpp
index 54091f1fd4..a1234e1fef 100644
--- a/src/core/SkResourceCache.cpp
+++ b/src/core/SkResourceCache.cpp
@@ -675,16 +675,18 @@ void SkResourceCache::TestDumpMemoryStatistics() {
 
 static void sk_trace_dump_visitor(const SkResourceCache::Rec& rec, void* context) {
     SkTraceMemoryDump* dump = static_cast<SkTraceMemoryDump*>(context);
-    SkString dump_name = SkStringPrintf("skia/sk_resource_cache/%s_%p", rec.getCategory(), &rec);
+    SkString dumpName = SkStringPrintf("skia/sk_resource_cache/%s_%p", rec.getCategory(), &rec);
     SkDiscardableMemory* discardable = rec.diagnostic_only_getDiscardable();
     if (discardable) {
-        dump->setDiscardableMemoryBacking(dump_name.c_str(), *discardable);
+        dump->setDiscardableMemoryBacking(dumpName.c_str(), *discardable);
     } else {
-        dump->dumpNumericValue(dump_name.c_str(), "size", "bytes", rec.bytesUsed());
-        dump->setMemoryBacking(dump_name.c_str(), "malloc", nullptr);
+        dump->dumpNumericValue(dumpName.c_str(), "size", "bytes", rec.bytesUsed());
+        dump->setMemoryBacking(dumpName.c_str(), "malloc", nullptr);
     }
 }
 
 void SkResourceCache::DumpMemoryStatistics(SkTraceMemoryDump* dump) {
+    // Since resource could be backed by malloc or discardable, the cache always dumps detailed
+    // stats to be accurate.
     VisitAll(sk_trace_dump_visitor, dump);
 }
diff --git a/tests/TraceMemoryDumpTest.cpp b/tests/TraceMemoryDumpTest.cpp
index cda0076318..a8cdbfeb55 100644
--- a/tests/TraceMemoryDumpTest.cpp
+++ b/tests/TraceMemoryDumpTest.cpp
@@ -24,9 +24,15 @@ public:
     void setDiscardableMemoryBacking(
         const char* dumpName,
         const SkDiscardableMemory& discardableMemoryObject) override { }
+    LevelOfDetail getRequestedDetails() const override {
+        return SkTraceMemoryDump::kObjectsBreakdowns_LevelOfDetail;
+    }
 };
 
 DEF_TEST(SkTraceMemoryDump, reporter) {
     TestSkTraceMemoryDump x;
     x.dumpNumericValue("foobar", "size", "bytes", 42);
+    if (x.getRequestedDetails() == SkTraceMemoryDump::kObjectsBreakdowns_LevelOfDetail) {
+        x.dumpNumericValue("foobar/object1", "size", "bytes", 23);
+    }
 }