skia2/tests/StreamTest.cpp
scroggo 028a4135aa Add a method to read a stream without advancing it.
Add a virtual method on SkStream which will do a "peek" some bytes, so
that those bytes are read, but the next call to read will be
unaffected.

Implement peek for SkMemoryStream, where the implementation is simple
and obvious.

Implement peek on SkFrontBufferedStream.

Add tests.

Motivated by decoding streams which cannot be rewound.

TBR=reed@google.com

BUG=skia:3257

Review URL: https://codereview.chromium.org/1044953002
2015-04-02 13:19:51 -07:00

268 lines
8.7 KiB
C++

/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "Resources.h"
#include "SkData.h"
#include "SkFrontBufferedStream.h"
#include "SkOSFile.h"
#include "SkRandom.h"
#include "SkStream.h"
#include "Test.h"
#ifndef SK_BUILD_FOR_WIN
#include <unistd.h>
#include <fcntl.h>
#endif
#define MAX_SIZE (256 * 1024)
static void test_loop_stream(skiatest::Reporter* reporter, SkStream* stream,
const void* src, size_t len, int repeat) {
SkAutoSMalloc<256> storage(len);
void* tmp = storage.get();
for (int i = 0; i < repeat; ++i) {
size_t bytes = stream->read(tmp, len);
REPORTER_ASSERT(reporter, bytes == len);
REPORTER_ASSERT(reporter, !memcmp(tmp, src, len));
}
// expect EOF
size_t bytes = stream->read(tmp, 1);
REPORTER_ASSERT(reporter, 0 == bytes);
// isAtEnd might not return true until after the first failing read.
REPORTER_ASSERT(reporter, stream->isAtEnd());
}
static void test_filestreams(skiatest::Reporter* reporter, const char* tmpDir) {
SkString path = SkOSPath::Join(tmpDir, "wstream_test");
const char s[] = "abcdefghijklmnopqrstuvwxyz";
{
SkFILEWStream writer(path.c_str());
if (!writer.isValid()) {
ERRORF(reporter, "Failed to create tmp file %s\n", path.c_str());
return;
}
for (int i = 0; i < 100; ++i) {
writer.write(s, 26);
}
}
{
SkFILEStream stream(path.c_str());
REPORTER_ASSERT(reporter, stream.isValid());
test_loop_stream(reporter, &stream, s, 26, 100);
SkAutoTDelete<SkStreamAsset> stream2(stream.duplicate());
test_loop_stream(reporter, stream2.get(), s, 26, 100);
}
{
FILE* file = ::fopen(path.c_str(), "rb");
SkFILEStream stream(file, SkFILEStream::kCallerPasses_Ownership);
REPORTER_ASSERT(reporter, stream.isValid());
test_loop_stream(reporter, &stream, s, 26, 100);
SkAutoTDelete<SkStreamAsset> stream2(stream.duplicate());
test_loop_stream(reporter, stream2.get(), s, 26, 100);
}
}
static void TestWStream(skiatest::Reporter* reporter) {
SkDynamicMemoryWStream ds;
const char s[] = "abcdefghijklmnopqrstuvwxyz";
int i;
for (i = 0; i < 100; i++) {
REPORTER_ASSERT(reporter, ds.write(s, 26));
}
REPORTER_ASSERT(reporter, ds.getOffset() == 100 * 26);
char* dst = new char[100 * 26 + 1];
dst[100*26] = '*';
ds.copyTo(dst);
REPORTER_ASSERT(reporter, dst[100*26] == '*');
for (i = 0; i < 100; i++) {
REPORTER_ASSERT(reporter, memcmp(&dst[i * 26], s, 26) == 0);
}
{
SkAutoTDelete<SkStreamAsset> stream(ds.detachAsStream());
REPORTER_ASSERT(reporter, 100 * 26 == stream->getLength());
REPORTER_ASSERT(reporter, ds.getOffset() == 0);
test_loop_stream(reporter, stream.get(), s, 26, 100);
SkAutoTDelete<SkStreamAsset> stream2(stream->duplicate());
test_loop_stream(reporter, stream2.get(), s, 26, 100);
SkAutoTDelete<SkStreamAsset> stream3(stream->fork());
REPORTER_ASSERT(reporter, stream3->isAtEnd());
char tmp;
size_t bytes = stream->read(&tmp, 1);
REPORTER_ASSERT(reporter, 0 == bytes);
stream3->rewind();
test_loop_stream(reporter, stream3.get(), s, 26, 100);
}
for (i = 0; i < 100; i++) {
REPORTER_ASSERT(reporter, ds.write(s, 26));
}
REPORTER_ASSERT(reporter, ds.getOffset() == 100 * 26);
{
SkAutoTUnref<SkData> data(ds.copyToData());
REPORTER_ASSERT(reporter, 100 * 26 == data->size());
REPORTER_ASSERT(reporter, memcmp(dst, data->data(), data->size()) == 0);
}
{
// Test that this works after a copyToData.
SkAutoTDelete<SkStreamAsset> stream(ds.detachAsStream());
REPORTER_ASSERT(reporter, ds.getOffset() == 0);
test_loop_stream(reporter, stream.get(), s, 26, 100);
SkAutoTDelete<SkStreamAsset> stream2(stream->duplicate());
test_loop_stream(reporter, stream2.get(), s, 26, 100);
}
delete[] dst;
SkString tmpDir = skiatest::GetTmpDir();
if (!tmpDir.isEmpty()) {
test_filestreams(reporter, tmpDir.c_str());
}
}
static void TestPackedUInt(skiatest::Reporter* reporter) {
// we know that packeduint tries to write 1, 2 or 4 bytes for the length,
// so we test values around each of those transitions (and a few others)
const size_t sizes[] = {
0, 1, 2, 0xFC, 0xFD, 0xFE, 0xFF, 0x100, 0x101, 32767, 32768, 32769,
0xFFFD, 0xFFFE, 0xFFFF, 0x10000, 0x10001,
0xFFFFFD, 0xFFFFFE, 0xFFFFFF, 0x1000000, 0x1000001,
0x7FFFFFFE, 0x7FFFFFFF, 0x80000000, 0x80000001, 0xFFFFFFFE, 0xFFFFFFFF
};
size_t i;
char buffer[sizeof(sizes) * 4];
SkMemoryWStream wstream(buffer, sizeof(buffer));
for (i = 0; i < SK_ARRAY_COUNT(sizes); ++i) {
bool success = wstream.writePackedUInt(sizes[i]);
REPORTER_ASSERT(reporter, success);
}
wstream.flush();
SkMemoryStream rstream(buffer, sizeof(buffer));
for (i = 0; i < SK_ARRAY_COUNT(sizes); ++i) {
size_t n = rstream.readPackedUInt();
if (sizes[i] != n) {
SkDebugf("-- %d: sizes:%x n:%x\n", i, sizes[i], n);
}
REPORTER_ASSERT(reporter, sizes[i] == n);
}
}
// Test that setting an SkMemoryStream to a NULL data does not result in a crash when calling
// methods that access fData.
static void TestDereferencingData(SkMemoryStream* memStream) {
memStream->read(NULL, 0);
memStream->getMemoryBase();
SkAutoDataUnref data(memStream->copyToData());
}
static void TestNullData() {
SkData* nullData = NULL;
SkMemoryStream memStream(nullData);
TestDereferencingData(&memStream);
memStream.setData(nullData);
TestDereferencingData(&memStream);
}
DEF_TEST(Stream, reporter) {
TestWStream(reporter);
TestPackedUInt(reporter);
TestNullData();
}
/**
* Tests peeking and then reading the same amount. The two should provide the
* same results.
* Returns whether the stream could peek.
*/
static bool 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();
if (!stream->peek(peekPtr, bytesToPeek)) {
return false;
}
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, bytesRead));
return true;
}
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 != NULL);
SkAutoTDelete<SkStream> bufferedStream(SkFrontBufferedStream::Create(dupe, bufferSize));
REPORTER_ASSERT(r, bufferedStream != NULL);
test_peeking_stream(r, bufferedStream, bufferSize);
}
DEF_TEST(StreamPeek, reporter) {
// Test a memory stream.
const char gAbcs[] = "abcdefghijklmnopqrstuvwxyz";
SkMemoryStream memStream(gAbcs, strlen(gAbcs), false);
test_peeking_stream(reporter, &memStream, memStream.getLength());
// Test an arbitrary file stream. file streams do not support peeking.
SkFILEStream fileStream(GetResourcePath("baby_tux.webp").c_str());
REPORTER_ASSERT(reporter, fileStream.isValid());
SkAutoMalloc storage(fileStream.getLength());
for (size_t i = 1; i < fileStream.getLength(); i++) {
REPORTER_ASSERT(reporter, !fileStream.peek(storage.get(), i));
}
// Now test some FrontBufferedStreams
for (size_t i = 1; i < memStream.getLength(); i++) {
test_peeking_front_buffered_stream(reporter, memStream, i);
}
}