/**
* Tests peeking and then reading the same amount. The two should provide the
* same results.
* Returns the amount successfully read minus the amount successfully peeked.
*/
static size_t compare_peek_to_read(skiatest::Reporter* reporter,
SkStream* stream, size_t bytesToPeek) {
// The rest of our tests won't be very interesting if bytesToPeek is zero.
REPORTER_ASSERT(reporter, bytesToPeek > 0);
SkAutoMalloc peekStorage(bytesToPeek);
SkAutoMalloc readStorage(bytesToPeek);
void* peekPtr = peekStorage.get();
void* readPtr = peekStorage.get();
const size_t bytesPeeked = stream->peek(peekPtr, bytesToPeek);
const size_t bytesRead = stream->read(readPtr, bytesToPeek);
// bytesRead should only be less than attempted if the stream is at the
// end.
REPORTER_ASSERT(reporter, bytesRead == bytesToPeek || stream->isAtEnd());
// peek and read should behave the same, except peek returned to the
// original position, so they read the same data.
REPORTER_ASSERT(reporter, !memcmp(peekPtr, readPtr, bytesPeeked));
// A stream should never be able to peek more than it can read.
REPORTER_ASSERT(reporter, bytesRead >= bytesPeeked);
return bytesRead - bytesPeeked;
}
static void test_peeking_front_buffered_stream(skiatest::Reporter* r,
const SkStream& original,
size_t bufferSize) {
SkStream* dupe = original.duplicate();
REPORTER_ASSERT(r, dupe != nullptr);
SkAutoTDelete<SkStream> bufferedStream(SkFrontBufferedStream::Create(dupe, bufferSize));
REPORTER_ASSERT(r, bufferedStream != nullptr);
size_t peeked = 0;
for (size_t i = 1; !bufferedStream->isAtEnd(); i++) {
const size_t unpeekableBytes = compare_peek_to_read(r, bufferedStream, i);
if (unpeekableBytes > 0) {
// This could not have returned a number greater than i.
REPORTER_ASSERT(r, unpeekableBytes <= i);
// We have reached the end of the buffer. Verify that it was at least
// bufferSize.
REPORTER_ASSERT(r, peeked + i - unpeekableBytes >= bufferSize);
// No more peeking is supported.
break;
}
peeked += i;
}
// Test that attempting to peek beyond the length of the buffer does not prevent rewinding.
bufferedStream.reset(SkFrontBufferedStream::Create(original.duplicate(), bufferSize));
REPORTER_ASSERT(r, bufferedStream != nullptr);
const size_t bytesToPeek = bufferSize + 1;
SkAutoMalloc peekStorage(bytesToPeek);
SkAutoMalloc readStorage(bytesToPeek);
for (size_t start = 0; start <= bufferSize; start++) {
// Skip to the starting point
REPORTER_ASSERT(r, bufferedStream->skip(start) == start);
const size_t bytesPeeked = bufferedStream->peek(peekStorage.get(), bytesToPeek);
if (0 == bytesPeeked) {
// Peeking should only fail completely if we have read/skipped beyond the buffer.
REPORTER_ASSERT(r, start >= bufferSize);
break;
}
// Only read the amount that was successfully peeked.
const size_t bytesRead = bufferedStream->read(readStorage.get(), bytesPeeked);
REPORTER_ASSERT(r, bytesRead == bytesPeeked);
REPORTER_ASSERT(r, !memcmp(peekStorage.get(), readStorage.get(), bytesPeeked));
// This should be safe to rewind.
REPORTER_ASSERT(r, bufferedStream->rewind());
}
}
static void testWritePad(skiatest::Reporter* reporter, SkWriter32* writer) {
// Create some random data to write.
const size_t dataSize = 10;
SkAutoTMalloc<uint32_t> originalData(dataSize);
{
SkRandom rand(0);
for (size_t i = 0; i < dataSize; i++) {
originalData[(int) i] = rand.nextU();
}
// Write the random data to the writer at different lengths for
// different alignments.
for (size_t len = 0; len < dataSize; len++) {
writer->writePad(originalData.get(), len);
}
}
size_t totalBytes = writer->bytesWritten();
SkAutoMalloc readStorage(totalBytes);
writer->flatten(readStorage.get());
SkReader32 reader;
reader.setMemory(readStorage.get(), totalBytes);
for (size_t len = 0; len < dataSize; len++) {
const char* readPtr = static_cast<const char*>(reader.skip(len));
// Ensure that the data read is the same as what was written.
REPORTER_ASSERT(reporter, memcmp(readPtr, originalData.get(), len) == 0);
// Ensure that the rest is padded with zeroes.
const char* stop = readPtr + SkAlign4(len);
readPtr += len;
while (readPtr < stop) {
REPORTER_ASSERT(reporter, *readPtr++ == 0);
}
}
}
