static void test_peeking_stream(skiatest::Reporter* r, SkStream* stream, size_t limit) {
size_t peeked = 0;
for (size_t i = 1; !stream->isAtEnd(); i++) {
const bool couldPeek = compare_peek_to_read(r, stream, i);
if (!couldPeek) {
REPORTER_ASSERT(r, peeked + i > limit);
// No more peeking is supported.
break;
}
peeked += i;
}
}
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 test_fully_peekable_stream(skiatest::Reporter* r, SkStream* stream, size_t limit) {
for (size_t i = 1; !stream->isAtEnd(); i++) {
REPORTER_ASSERT(r, compare_peek_to_read(r, stream, i) == 0);
}
}