Add SkDebugf trace event handler.

Also adds more trace events to GPU backend.

Change-Id: Ifa5f0cd4b1fd582f0cc30d37d9e6414dc498c75d
Reviewed-on: https://skia-review.googlesource.com/24622
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/tools/trace/SkDebugfTracer.cpp b/tools/trace/SkDebugfTracer.cpp
new file mode 100644
index 0000000..272af78
--- /dev/null
+++ b/tools/trace/SkDebugfTracer.cpp
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkDebugfTracer.h"
+#include "SkTraceEvent.h"
+
+SkEventTracer::Handle SkDebugfTracer::addTraceEvent(char phase,
+                                                    const uint8_t* categoryEnabledFlag,
+                                                    const char* name,
+                                                    uint64_t id,
+                                                    int numArgs,
+                                                    const char** argNames,
+                                                    const uint8_t* argTypes,
+                                                    const uint64_t* argValues,
+                                                    uint8_t flags) {
+    SkString args;
+    for (int i = 0; i < numArgs; ++i) {
+        if (i > 0) {
+            args.append(", ");
+        } else {
+            args.append(" ");
+        }
+        switch (argTypes[i]) {
+            case TRACE_VALUE_TYPE_BOOL:
+                args.appendf("%s=%s",
+                             argNames[i],
+                             (*reinterpret_cast<bool*>(argValues[i]) ? "true" : "false"));
+                break;
+            case TRACE_VALUE_TYPE_UINT:
+                args.appendf("%s=%u", argNames[i], static_cast<uint32_t>(argValues[i]));
+                break;
+            case TRACE_VALUE_TYPE_INT:
+                args.appendf("%s=%d", argNames[i], static_cast<int32_t>(argValues[i]));
+                break;
+            case TRACE_VALUE_TYPE_DOUBLE:
+                args.appendf("%s=%g", argNames[i], *SkTCast<const double*>(&argValues[i]));
+                break;
+            case TRACE_VALUE_TYPE_POINTER:
+                args.appendf("%s=0x%p", argNames[i], reinterpret_cast<void*>(argValues[i]));
+                break;
+            case TRACE_VALUE_TYPE_STRING:
+            case TRACE_VALUE_TYPE_COPY_STRING: {
+                static constexpr size_t kMaxLen = 20;
+                const char* str = reinterpret_cast<const char*>(argValues[i]);
+                SkString string(str);
+                size_t truncAt = string.size();
+                size_t newLineAt = SkStrFind(string.c_str(), "\n");
+                if (newLineAt > 0) {
+                    truncAt = newLineAt;
+                }
+                truncAt = SkTMin(truncAt, kMaxLen);
+                if (truncAt < string.size()) {
+                    string.resize(truncAt);
+                    string.append("...");
+                }
+                args.appendf("%s=\"%s\"", argNames[i], string.c_str());
+                break;
+            }
+            default:
+                args.appendf("%s=<unknown type>", argNames[i]);
+                break;
+        }
+    }
+    bool open = (phase == TRACE_EVENT_PHASE_COMPLETE);
+    if (open) {
+        SkDebugf(
+                "[% 2d]%s %s%s #%d {\n", fIndent.size(), fIndent.c_str(), name, args.c_str(), fCnt);
+        fIndent.append(" ");
+    } else {
+        SkDebugf("%s%s #%d\n", name, args.c_str(), fCnt);
+    }
+    ++fCnt;
+    return 0;
+}
+
+void SkDebugfTracer::updateTraceEventDuration(const uint8_t* categoryEnabledFlag,
+                                              const char* name,
+                                              SkEventTracer::Handle handle) {
+    fIndent.resize(fIndent.size() - 1);
+    SkDebugf("[% 2d]%s } %s\n", fIndent.size(), fIndent.c_str(), name);
+}
+
+const uint8_t* SkDebugfTracer::getCategoryGroupEnabled(const char* name) {
+    static uint8_t yes = SkEventTracer::kEnabledForRecording_CategoryGroupEnabledFlags;
+    return &yes;
+}