extract some common code from PictureRenderer

tools/image_expectations.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkBitmap.h"
+#include "SkBitmapHasher.h"
+#include "SkData.h"
+#include "SkDataUtils.h"
+#include "SkJSONCPP.h"
+#include "SkOSFile.h"
+#include "SkStream.h"
+#include "SkTypes.h"
+
+#include "image_expectations.h"
+
+/*
+ * TODO(epoger): Make constant strings consistent instead of mixing hypenated and camel-caps.
+ *
+ * TODO(epoger): Similar constants are already maintained in 2 other places:
+ * gm/gm_json.py and gm/gm_expectations.cpp. We shouldn't add yet a third place.
+ * Figure out a way to share the definitions instead.
+ *
+ * Note that, as of https://codereview.chromium.org/226293002 , the JSON
+ * schema used here has started to differ from the one in gm_expectations.cpp .
+ * TODO(epoger): Consider getting GM and render_pictures to use the same JSON
+ * output module.
+ */
+const static char kJsonKey_ActualResults[] = "actual-results";
+const static char kJsonKey_Header[] = "header";
+const static char kJsonKey_Header_Type[] = "type";
+const static char kJsonKey_Header_Revision[] = "revision";  // unique within Type
+const static char kJsonKey_Image_ChecksumAlgorithm[] = "checksumAlgorithm";
+const static char kJsonKey_Image_ChecksumValue[] = "checksumValue";
+const static char kJsonKey_Image_ComparisonResult[] = "comparisonResult";
+const static char kJsonKey_Image_Filepath[] = "filepath";
+const static char kJsonKey_Source_TiledImages[] = "tiled-images";
+const static char kJsonKey_Source_WholeImage[] = "whole-image";
+// Values (not keys) that are written out by this JSON generator
+const static char kJsonValue_Header_Type[] = "ChecksummedImages";
+const static int kJsonValue_Header_Revision = 1;
+const static char kJsonValue_Image_ChecksumAlgorithm_Bitmap64bitMD5[] = "bitmap-64bitMD5";
+const static char kJsonValue_Image_ComparisonResult_NoComparison[] = "no-comparison";
+
+namespace sk_tools {
+
+    void ImageResultsSummary::add(const char *sourceName, const char *fileName, uint64_t hash,
+                                  const int *tileNumber) {
+        Json::Value image;
+        image[kJsonKey_Image_ChecksumAlgorithm] = kJsonValue_Image_ChecksumAlgorithm_Bitmap64bitMD5;
+        image[kJsonKey_Image_ChecksumValue] = Json::UInt64(hash);
+        image[kJsonKey_Image_ComparisonResult] = kJsonValue_Image_ComparisonResult_NoComparison;
+        image[kJsonKey_Image_Filepath] = fileName;
+        if (NULL == tileNumber) {
+            fActualResults[sourceName][kJsonKey_Source_WholeImage] = image;
+        } else {
+            fActualResults[sourceName][kJsonKey_Source_TiledImages][*tileNumber] = image;
+        }
+    }
+
+    void ImageResultsSummary::add(const char *sourceName, const char *fileName, const SkBitmap& bitmap,
+                                  const int *tileNumber) {
+        uint64_t hash;
+        SkAssertResult(SkBitmapHasher::ComputeDigest(bitmap, &hash));
+        this->add(sourceName, fileName, hash, tileNumber);
+    }
+
+    void ImageResultsSummary::writeToFile(const char *filename) {
+        Json::Value header;
+        header[kJsonKey_Header_Type] = kJsonValue_Header_Type;
+        header[kJsonKey_Header_Revision] = kJsonValue_Header_Revision;
+        Json::Value root;
+        root[kJsonKey_Header] = header;
+        root[kJsonKey_ActualResults] = fActualResults;
+        std::string jsonStdString = root.toStyledString();
+        SkFILEWStream stream(filename);
+        stream.write(jsonStdString.c_str(), jsonStdString.length());
+    }
+
+} // namespace sk_tools