GM: specify that currently used checksums are CityHashes of SkBitmaps

gm/gm_expectations.cpp

Index: gm/gm_expectations.cpp
===================================================================
--- gm/gm_expectations.cpp	(revision 0)
+++ gm/gm_expectations.cpp	(revision 0)
@@ -0,0 +1,166 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm_expectations.h"
+#include "SkBitmapHasher.h"
+#include "SkImageDecoder.h"
+
+#define DEBUGFAIL_SEE_STDERR SkDEBUGFAIL("see stderr for message")
+
+// EPOGER: misc cleanup (including 100 char wraps)
+namespace skiagm {
+
+    Expectations::Expectations(bool ignoreFailure) {
+        fIgnoreFailure = ignoreFailure;
+    }
+
+    Expectations::Expectations(const SkBitmap& bitmap, bool ignoreFailure) {

[epoger, 2013/04/25 17:23:20]

patchset 2: moved most implementation details out of gm_expectations.h into new
gm_expectations.cpp file.  

This will allow us to hide future changes within gm_expectations.cpp, confident
that gmmain.cpp and other source files will not depend on implementation details
that used to be stored in the header file.

All of the implementations were moved in VERBATIM from gm_expectations.h.  If I
make any changes to the implementation logic, that will be in a separate
patchset.

+        fBitmap = bitmap;
+        fIgnoreFailure = ignoreFailure;
+        SkHashDigest digest;
+        // TODO(epoger): Better handling for error returned by ComputeDigest()?
+        // For now, we just report a digest of 0 in error cases, like before.
+        if (!SkBitmapHasher::ComputeDigest(bitmap, &digest)) {
+            digest = 0;
+        }
+        fAllowedBitmapCityhashes.push_back() = digest;
+    }
+
+    Expectations::Expectations(Json::Value jsonElement) {
+        if (jsonElement.empty()) {
+            fIgnoreFailure = kDefaultIgnoreFailure;
+        } else {
+            Json::Value ignoreFailure = jsonElement[kJsonKey_ExpectedResults_IgnoreFailure];
+            if (ignoreFailure.isNull()) {
+                fIgnoreFailure = kDefaultIgnoreFailure;
+            } else if (!ignoreFailure.isBool()) {
+                gm_fprintf(stderr, "found non-boolean json value"
+                           " for key '%s' in element '%s'\n",
+                           kJsonKey_ExpectedResults_IgnoreFailure,
+                           jsonElement.toStyledString().c_str());
+                DEBUGFAIL_SEE_STDERR;
+                fIgnoreFailure = kDefaultIgnoreFailure;
+            } else {
+                fIgnoreFailure = ignoreFailure.asBool();
+            }
+
+            Json::Value allowedChecksums = jsonElement[kJsonKey_ExpectedResults_AllowedBitmapCityhashes];
+            if (allowedChecksums.isNull()) {
+                // ok, we'll just assume there aren't any expected checksums to compare against
+            } else if (!allowedChecksums.isArray()) {
+                gm_fprintf(stderr, "found non-array json value"
+                           " for key '%s' in element '%s'\n",
+                           kJsonKey_ExpectedResults_AllowedBitmapCityhashes,
+                           jsonElement.toStyledString().c_str());
+                DEBUGFAIL_SEE_STDERR;
+            } else {
+                for (Json::ArrayIndex i=0; i<allowedChecksums.size(); i++) {
+                    Json::Value checksumElement = allowedChecksums[i];
+                    if (!checksumElement.isIntegral()) {
+                        gm_fprintf(stderr, "found non-integer checksum"
+                                   " in json element '%s'\n",
+                                   jsonElement.toStyledString().c_str());
+                        DEBUGFAIL_SEE_STDERR;
+                    } else {
+                        fAllowedBitmapCityhashes.push_back() = asChecksum(checksumElement);
+                    }
+                }
+            }
+        }
+    }
+
+    bool Expectations::match(Checksum actualChecksum) const {
+        for (int i=0; i < this->fAllowedBitmapCityhashes.count(); i++) {
+            Checksum allowedChecksum = this->fAllowedBitmapCityhashes[i];
+            if (allowedChecksum == actualChecksum) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    Json::Value Expectations::allowedChecksumsAsJson() const {
+        Json::Value allowedChecksumArray;
+        if (!this->fAllowedBitmapCityhashes.empty()) {
+            for (int i=0; i < this->fAllowedBitmapCityhashes.count(); i++) {
+                Checksum allowedChecksum = this->fAllowedBitmapCityhashes[i];
+                allowedChecksumArray.append(asJsonValue(allowedChecksum));
+            }
+        }
+        return allowedChecksumArray;
+    }
+
+    Expectations IndividualImageExpectationsSource::get(const char *testName) SK_OVERRIDE {
+        SkString path = make_filename(fRootDir.c_str(), "", testName,
+                                      "png");
+        SkBitmap referenceBitmap;
+        bool decodedReferenceBitmap =
+            SkImageDecoder::DecodeFile(path.c_str(), &referenceBitmap,
+                                       SkBitmap::kARGB_8888_Config,
+                                       SkImageDecoder::kDecodePixels_Mode,
+                                       NULL);
+        if (decodedReferenceBitmap) {
+            return Expectations(referenceBitmap);
+        } else {
+            return Expectations();
+        }
+    }
+
+    JsonExpectationsSource::JsonExpectationsSource(const char *jsonPath) {
+        parse(jsonPath, &fJsonRoot);
+        fJsonExpectedResults = fJsonRoot[kJsonKey_ExpectedResults];
+    }
+
+    Expectations JsonExpectationsSource::get(const char *testName) SK_OVERRIDE {
+        return Expectations(fJsonExpectedResults[testName]);
+    }
+
+    /*static*/ SkData* JsonExpectationsSource::readIntoSkData(SkStream &stream, size_t maxBytes) {
+        if (0 == maxBytes) {
+            return SkData::NewEmpty();
+        }
+        char* bufStart = reinterpret_cast<char *>(sk_malloc_throw(maxBytes));
+        char* bufPtr = bufStart;
+        size_t bytesRemaining = maxBytes;
+        while (bytesRemaining > 0) {
+            size_t bytesReadThisTime = stream.read(bufPtr, bytesRemaining);
+            if (0 == bytesReadThisTime) {
+                break;
+            }
+            bytesRemaining -= bytesReadThisTime;
+            bufPtr += bytesReadThisTime;
+        }
+        return SkData::NewFromMalloc(bufStart, maxBytes - bytesRemaining);
+    }
+
+    /*static*/ bool JsonExpectationsSource::parse(const char *jsonPath, Json::Value *jsonRoot) {
+        SkFILEStream inFile(jsonPath);
+        if (!inFile.isValid()) {
+            gm_fprintf(stderr, "unable to read JSON file %s\n", jsonPath);
+            DEBUGFAIL_SEE_STDERR;
+            return false;
+        }
+
+        SkAutoDataUnref dataRef(readFileIntoSkData(inFile));
+        if (NULL == dataRef.get()) {
+            gm_fprintf(stderr, "error reading JSON file %s\n", jsonPath);
+            DEBUGFAIL_SEE_STDERR;
+            return false;
+        }
+
+        const char *bytes = reinterpret_cast<const char *>(dataRef.get()->data());
+        size_t size = dataRef.get()->size();
+        Json::Reader reader;
+        if (!reader.parse(bytes, bytes+size, *jsonRoot)) {
+            gm_fprintf(stderr, "error parsing JSON file %s\n", jsonPath);
+            DEBUGFAIL_SEE_STDERR;
+            return false;
+        }
+        return true;
+    }
+
+}