'../tests/BlitRowTest.cpp',
'../tests/BlurTest.cpp',
'../tests/CanvasTest.cpp',
+ '../tests/ChecksumTest.cpp',
'../tests/ClampRangeTest.cpp',
'../tests/ClipCacheTest.cpp',
'../tests/ClipCubicTest.cpp',
'images.gyp:images',
'pdf.gyp:pdf',
'tools.gyp:picture_utils',
+ 'utils.gyp:utils',
],
'conditions': [
[ 'skia_gpu == 1', {
'../src/utils/SkBitSet.h',
'../src/utils/SkBoundaryPatch.cpp',
'../src/utils/SkCamera.cpp',
+ '../src/utils/SkConsistentChecksum.h',
'../src/utils/SkCubicInterval.cpp',
'../src/utils/SkCullPoints.cpp',
'../src/utils/SkDeferredCanvas.cpp',
--- /dev/null
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkConsistentChecksum_DEFINED
+#define SkConsistentChecksum_DEFINED
+
+#include "SkTypes.h"
+
+class SkConsistentChecksum : SkNoncopyable {
+private:
+ /*
+ * Our Rotate and Mash helpers are meant to automatically do the right
+ * thing depending if sizeof(uintptr_t) is 4 or 8.
+ */
+ enum {
+ ROTR = 17,
+ ROTL = sizeof(uintptr_t) * 8 - ROTR,
+ HALFBITS = sizeof(uintptr_t) * 4
+ };
+
+ static inline uintptr_t Mash(uintptr_t total, uintptr_t value) {
+ return ((total >> ROTR) | (total << ROTL)) ^ value;
+ }
+
+public:
+ /**
+ * Compute a 32-bit checksum for a given data block
+ *
+ * WARNING: As of 1 Nov 2012, this algorithm is still in
+ * flux... but once we get it doing what we want, it will be:
+ * 1. consistent across revisions of the library (for a given set
+ * of bytes, the checksum generated at one revision of the Skia
+ * library will match the one generated on any other revision of
+ * the Skia library)
+ * 2. consistent across platforms (for a given
+ * set of bytes, the checksum generated on one platform will
+ * match the one generated on any other platform)
+ *
+ * @param data Memory address of the data block to be processed. Must be
+ * 32-bit aligned.
+ * @param size Size of the data block in bytes. Must be a multiple of 4.
+ * @return checksum result
+ */
+ static uint32_t Compute(const uint32_t* data, size_t size) {
+ SkASSERT(SkIsAlign4(size));
+
+ /*
+ * We want to let the compiler use 32bit or 64bit addressing and math
+ * so we use uintptr_t as our magic type. This makes the code a little
+ * more obscure (we can't hard-code 32 or 64 anywhere, but have to use
+ * sizeof()).
+ */
+ uintptr_t result = 0;
+ const uintptr_t* ptr = reinterpret_cast<const uintptr_t*>(data);
+
+ /*
+ * count the number of quad element chunks. This takes into account
+ * if we're on a 32bit or 64bit arch, since we use sizeof(uintptr_t)
+ * to compute how much to shift-down the size.
+ */
+ size_t n4 = size / (sizeof(uintptr_t) << 2);
+ for (size_t i = 0; i < n4; ++i) {
+ result = Mash(result, *ptr++);
+ result = Mash(result, *ptr++);
+ result = Mash(result, *ptr++);
+ result = Mash(result, *ptr++);
+ }
+ size &= ((sizeof(uintptr_t) << 2) - 1);
+
+ data = reinterpret_cast<const uint32_t*>(ptr);
+ const uint32_t* stop = data + (size >> 2);
+ while (data < stop) {
+ result = Mash(result, *data++);
+ }
+
+ /*
+ * smash us down to 32bits if we were 64. Note that when uintptr_t is
+ * 32bits, this code-path should go away, but I still got a warning
+ * when I wrote
+ * result ^= result >> 32;
+ * since >>32 is undefined for 32bit ints, hence the wacky HALFBITS
+ * define.
+ */
+ if (8 == sizeof(result)) {
+ result ^= result >> HALFBITS;
+ }
+ return static_cast<uint32_t>(result);
+ }
+};
+
+#endif
--- /dev/null
+
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "Test.h"
+#include "SkChecksum.h"
+#include "SkConsistentChecksum.h"
+
+namespace skiatest {
+ class ChecksumTestClass : public Test {
+ public:
+ static Test* Factory(void*) {return SkNEW(ChecksumTestClass); }
+ protected:
+ virtual void onGetName(SkString* name) { name->set("Checksum"); }
+ virtual void onRun(Reporter* reporter) {
+ this->fReporter = reporter;
+ RunTest();
+ }
+ private:
+ enum Algorithm {
+ kSkChecksum,
+ kSkConsistentChecksum
+ };
+
+ // Call Compute(data, size) on the appropriate checksum algorithm,
+ // depending on this->fWhichAlgorithm.
+ uint32_t ComputeChecksum(uint32_t* data, size_t size) {
+ // Our checksum algorithms require 32-bit aligned data.
+ // If either of these tests fail, then the algorithm
+ // doesn't have a chance.
+ REPORTER_ASSERT_MESSAGE(fReporter,
+ reinterpret_cast<uintptr_t>(data) % 4 == 0,
+ "test data pointer is not 32-bit aligned");
+ REPORTER_ASSERT_MESSAGE(fReporter, SkIsAlign4(size),
+ "test data size is not 32-bit aligned");
+
+ switch(fWhichAlgorithm) {
+ case kSkChecksum:
+ return SkChecksum::Compute(data, size);
+ case kSkConsistentChecksum:
+ return SkConsistentChecksum::Compute(data, size);
+ default:
+ SkString message("fWhichAlgorithm has unknown value ");
+ message.appendf("%d", fWhichAlgorithm);
+ fReporter->reportFailed(message);
+ }
+ // we never get here
+ return 0;
+ }
+
+ // Confirm that the checksum algorithm (specified by fWhichAlgorithm)
+ // generates the same results if called twice over the same data.
+ void TestChecksumSelfConsistency(size_t buf_size) {
+ SkAutoMalloc storage(buf_size);
+ uint32_t* ptr = (uint32_t*)storage.get();
+ char* cptr = (char*)ptr;
+
+ sk_bzero(ptr, buf_size);
+ uint32_t prev = 0;
+
+ // assert that as we change values (from 0 to non-zero) in
+ // our buffer, we get a different value
+ for (size_t i = 0; i < buf_size; ++i) {
+ cptr[i] = (i & 0x7f) + 1; // need some non-zero value here
+
+ // Try checksums of different-sized chunks, but always
+ // 32-bit aligned and big enough to contain all the
+ // nonzero bytes.
+ size_t checksum_size = (((i/4)+1)*4);
+ REPORTER_ASSERT(fReporter, checksum_size <= buf_size);
+
+ uint32_t curr = ComputeChecksum(ptr, checksum_size);
+ REPORTER_ASSERT(fReporter, prev != curr);
+ uint32_t again = ComputeChecksum(ptr, checksum_size);
+ REPORTER_ASSERT(fReporter, again == curr);
+ prev = curr;
+ }
+ }
+
+ // Return the checksum of a portion of this static test data
+ // (8 bytes repeated twice): "1234567812345678"
+ uint32_t GetTestDataChecksum(size_t offset, size_t len) {
+ static char testbytes[] = "1234567812345678";
+ uint32_t* ptr = reinterpret_cast<uint32_t*>(testbytes);
+ return ComputeChecksum(ptr, len);
+ }
+
+ void RunTest() {
+ // Test self-consistency of checksum algorithms.
+ fWhichAlgorithm = kSkChecksum;
+ REPORTER_ASSERT(fReporter,
+ GetTestDataChecksum(0, 8) ==
+ GetTestDataChecksum(8, 8));
+ TestChecksumSelfConsistency(128);
+ fWhichAlgorithm = kSkConsistentChecksum;
+ REPORTER_ASSERT(fReporter,
+ GetTestDataChecksum(0, 8) ==
+ GetTestDataChecksum(8, 8));
+ TestChecksumSelfConsistency(128);
+
+ // Test checksum results that should be consistent across
+ // versions and platforms.
+ fWhichAlgorithm = kSkChecksum;
+ REPORTER_ASSERT(fReporter, ComputeChecksum(NULL, 0) == 0);
+ fWhichAlgorithm = kSkConsistentChecksum;
+ REPORTER_ASSERT(fReporter, ComputeChecksum(NULL, 0) == 0);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(0, 8) == 0xa12fac2c);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(8, 8) == 0xa12fac2c);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(8, 4) == 0x34333231);
+ }
+
+ Reporter* fReporter;
+ Algorithm fWhichAlgorithm;
+ };
+
+ static TestRegistry gReg(ChecksumTestClass::Factory);
+}
*/
#include "Test.h"
#include "SkRandom.h"
-#include "SkChecksum.h"
#include "SkTSort.h"
-// assert that as we change values (from 0 to non-zero) in our buffer, we
-// get a different value
-static void test_checksum(skiatest::Reporter* reporter, size_t size) {
- SkAutoMalloc storage(size);
- uint32_t* ptr = (uint32_t*)storage.get();
- char* cptr = (char*)ptr;
-
- sk_bzero(ptr, size);
- uint32_t prev = 0;
- for (size_t i = 0; i < size; ++i) {
- cptr[i] = 0x5B; // just need some non-zero value here
- uint32_t curr = SkChecksum::Compute(ptr, size);
- REPORTER_ASSERT(reporter, prev != curr);
- prev = curr;
- }
-}
-
-static void test_checksum(skiatest::Reporter* reporter) {
- REPORTER_ASSERT(reporter, SkChecksum::Compute(NULL, 0) == 0);
-
- for (size_t size = 4; size <= 1000; size += 4) {
- test_checksum(reporter, size);
- }
-}
-
extern "C" {
static int compare_int(const void* a, const void* b) {
return *(const int*)a - *(const int*)b;
if (false) { // avoid bit rot, suppress warning
compare_int(array, array);
}
-
- test_checksum(reporter);
}
// need tests for SkStrSearch
projects / platform / upstream / libSkiaSharp.git / commitdiff