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 +1,215 @@
+/*
+ * 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")
+
+const static char kJsonKey_ActualResults[]   = "actual-results";
+const static char kJsonKey_ActualResults_Failed[]        = "failed";
+const static char kJsonKey_ActualResults_FailureIgnored[]= "failure-ignored";
+const static char kJsonKey_ActualResults_NoComparison[]  = "no-comparison";
+const static char kJsonKey_ActualResults_Succeeded[]     = "succeeded";
+const static char kJsonKey_ActualResults_AnyStatus_BitmapCityhash[]  = "bitmap-cityhash";
+
+const static char kJsonKey_ExpectedResults[] = "expected-results";
+const static char kJsonKey_ExpectedResults_AllowedBitmapCityhashes[] = "allowed-bitmap-cityhashes";
+const static char kJsonKey_ExpectedResults_IgnoreFailure[]           = "ignore-failure";
+
+namespace skiagm {
+
+    // TODO(epoger): This currently assumes that the result SkHashDigest was
+    // generated as a CityHash of an SkBitmap.  We'll need to allow for other
+    // hash types to cover non-bitmaps, MD5 instead of CityHash, etc.
+    Json::Value ActualResultAsJsonValue(const SkHashDigest& result) {
+        Json::Value jsonValue;
+        jsonValue[kJsonKey_ActualResults_AnyStatus_BitmapCityhash] = asJsonValue(result);
+        return jsonValue;
+    }
+
+    Json::Value CreateJsonTree(Json::Value expectedResults,
+                               Json::Value actualResultsFailed,
+                               Json::Value actualResultsFailureIgnored,
+                               Json::Value actualResultsNoComparison,
+                               Json::Value actualResultsSucceeded) {
+        Json::Value actualResults;
+        actualResults[kJsonKey_ActualResults_Failed] = actualResultsFailed;
+        actualResults[kJsonKey_ActualResults_FailureIgnored] = actualResultsFailureIgnored;
+        actualResults[kJsonKey_ActualResults_NoComparison] = actualResultsNoComparison;
+        actualResults[kJsonKey_ActualResults_Succeeded] = actualResultsSucceeded;
+        Json::Value root;
+        root[kJsonKey_ActualResults] = actualResults;
+        root[kJsonKey_ExpectedResults] = expectedResults;
+        return root;
+    }
+
+
+    // Expectations class...
+
+    Expectations::Expectations(bool ignoreFailure) {
+        fIgnoreFailure = ignoreFailure;
+    }
+
+    Expectations::Expectations(const SkBitmap& bitmap, bool ignoreFailure) {
+        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::asJsonValue() const {
+        Json::Value allowedChecksumArray;
+        if (!this->fAllowedBitmapCityhashes.empty()) {
+            for (int i=0; i < this->fAllowedBitmapCityhashes.count(); i++) {
+                Checksum allowedChecksum = this->fAllowedBitmapCityhashes[i];
+                allowedChecksumArray.append(Json::UInt64(allowedChecksum));
+            }
+        }
+
+        Json::Value jsonValue;
+        jsonValue[kJsonKey_ExpectedResults_AllowedBitmapCityhashes] = allowedChecksumArray;
+        jsonValue[kJsonKey_ExpectedResults_IgnoreFailure] = this->ignoreFailure();
+        return jsonValue;
+    }
+
+
+    // IndividualImageExpectationsSource class...
+
+    Expectations IndividualImageExpectationsSource::get(const char *testName) {
+        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 class...
+
+    JsonExpectationsSource::JsonExpectationsSource(const char *jsonPath) {
+        parse(jsonPath, &fJsonRoot);
+        fJsonExpectedResults = fJsonRoot[kJsonKey_ExpectedResults];
+    }
+
+    Expectations JsonExpectationsSource::get(const char *testName) {
+        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;
+    }
+
+}