Replace SkConsistentChecksum with SkCityHash (now including CityHash via DEPS)
Alternative to https://codereview.appspot.com/6847087/ ('Change SkConsistentChecksum to use SuperFastHash')
Review URL: https://codereview.appspot.com/6867060
git-svn-id: http://skia.googlecode.com/svn/trunk@6701 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/ChecksumTest.cpp b/tests/ChecksumTest.cpp
index 5d5d83b..dea0eef 100644
--- a/tests/ChecksumTest.cpp
+++ b/tests/ChecksumTest.cpp
@@ -7,7 +7,10 @@
*/
#include "Test.h"
#include "SkChecksum.h"
-#include "SkConsistentChecksum.h"
+#include "SkCityHash.h"
+
+// Word size that is large enough to hold results of any checksum type.
+typedef uint64_t checksum_result;
namespace skiatest {
class ChecksumTestClass : public Test {
@@ -22,26 +25,25 @@
private:
enum Algorithm {
kSkChecksum,
- kSkConsistentChecksum
+ kSkCityHash32,
+ kSkCityHash64
};
// 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");
-
+ checksum_result ComputeChecksum(const char *data, size_t size) {
switch(fWhichAlgorithm) {
case kSkChecksum:
- return SkChecksum::Compute(data, size);
- case kSkConsistentChecksum:
- return SkConsistentChecksum::Compute(data, size);
+ 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");
+ return SkChecksum::Compute(reinterpret_cast<const uint32_t *>(data), size);
+ case kSkCityHash32:
+ return SkCityHash::Compute32(data, size);
+ case kSkCityHash64:
+ return SkCityHash::Compute64(data, size);
default:
SkString message("fWhichAlgorithm has unknown value ");
message.appendf("%d", fWhichAlgorithm);
@@ -55,16 +57,22 @@
// 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;
+ char* ptr = reinterpret_cast<char *>(storage.get());
+
+ REPORTER_ASSERT(fReporter,
+ GetTestDataChecksum(8, 0) ==
+ GetTestDataChecksum(8, 0));
+ REPORTER_ASSERT(fReporter,
+ GetTestDataChecksum(8, 0) !=
+ GetTestDataChecksum(8, 1));
sk_bzero(ptr, buf_size);
- uint32_t prev = 0;
+ checksum_result 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
+ ptr[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
@@ -73,9 +81,9 @@
size_t checksum_size = (((i/4)+1)*4);
REPORTER_ASSERT(fReporter, checksum_size <= buf_size);
- uint32_t curr = ComputeChecksum(ptr, checksum_size);
+ checksum_result curr = ComputeChecksum(ptr, checksum_size);
REPORTER_ASSERT(fReporter, prev != curr);
- uint32_t again = ComputeChecksum(ptr, checksum_size);
+ checksum_result again = ComputeChecksum(ptr, checksum_size);
REPORTER_ASSERT(fReporter, again == curr);
prev = curr;
}
@@ -84,48 +92,49 @@
// Return the checksum of a buffer of bytes 'len' long.
// The pattern of values within the buffer will be consistent
// for every call, based on 'seed'.
- uint32_t GetTestDataChecksum(size_t len, char seed=0) {
+ checksum_result GetTestDataChecksum(size_t len, char seed=0) {
SkAutoMalloc storage(len);
- uint32_t* start = (uint32_t *)storage.get();
- char* ptr = (char *)start;
+ char* start = reinterpret_cast<char *>(storage.get());
+ char* ptr = start;
for (size_t i = 0; i < len; ++i) {
*ptr++ = ((seed+i) & 0x7f);
}
- uint32_t result = ComputeChecksum(start, len);
+ checksum_result result = ComputeChecksum(start, len);
return result;
}
void RunTest() {
// Test self-consistency of checksum algorithms.
fWhichAlgorithm = kSkChecksum;
- REPORTER_ASSERT(fReporter,
- GetTestDataChecksum(8, 0) ==
- GetTestDataChecksum(8, 0));
- REPORTER_ASSERT(fReporter,
- GetTestDataChecksum(8, 0) !=
- GetTestDataChecksum(8, 1));
TestChecksumSelfConsistency(128);
- fWhichAlgorithm = kSkConsistentChecksum;
- REPORTER_ASSERT(fReporter,
- GetTestDataChecksum(8, 0) ==
- GetTestDataChecksum(8, 0));
- REPORTER_ASSERT(fReporter,
- GetTestDataChecksum(8, 0) !=
- GetTestDataChecksum(8, 1));
+ fWhichAlgorithm = kSkCityHash32;
+ TestChecksumSelfConsistency(128);
+ fWhichAlgorithm = kSkCityHash64;
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(4) == 0x03020100);
- REPORTER_ASSERT(fReporter, GetTestDataChecksum(8) == 0x07860485);
+ fWhichAlgorithm = kSkCityHash32;
+ REPORTER_ASSERT(fReporter, ComputeChecksum(NULL, 0) == 0xdc56d17a);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(4) == 0x616e1132);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(8) == 0xeb0fd2d6);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(128) == 0x5321e430);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(132) == 0x924a10e4);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(256) == 0xd4de9dc9);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(260) == 0xecf0325d);
+ fWhichAlgorithm = kSkCityHash64;
+ REPORTER_ASSERT(fReporter, ComputeChecksum(NULL, 0) == 0x9ae16a3b2f90404f);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(4) == 0x82bffd898958e540);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(8) == 0xad5a13e1e8e93b98);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(128) == 0x10b153630af1f395);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(132) == 0x7db71dc4adcc6647);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(256) == 0xeee763519b91b010);
+ REPORTER_ASSERT(fReporter, GetTestDataChecksum(260) == 0x2fe19e0b2239bc23);
// TODO: note the weakness exposed by these collisions...
- // We need to improve the SkConsistentChecksum algorithm
- // (and maybe SkChecksum too?)
+ // We need to improve the SkChecksum algorithm.
// We would prefer that these asserts FAIL!
// Filed as https://code.google.com/p/skia/issues/detail?id=981
// ('SkChecksum algorithm allows for way too many collisions')
@@ -134,11 +143,6 @@
GetTestDataChecksum(128) == GetTestDataChecksum(256));
REPORTER_ASSERT(fReporter,
GetTestDataChecksum(132) == GetTestDataChecksum(260));
- fWhichAlgorithm = kSkConsistentChecksum;
- REPORTER_ASSERT(fReporter, GetTestDataChecksum(128) == 0);
- REPORTER_ASSERT(fReporter, GetTestDataChecksum(132) == 0x03020100);
- REPORTER_ASSERT(fReporter, GetTestDataChecksum(256) == 0);
- REPORTER_ASSERT(fReporter, GetTestDataChecksum(260) == 0x03020100);
}
Reporter* fReporter;