Files
nearby/internal/platform/input_stream_test.cc
Janusz Sobczak 1a78b33a89 Add InputStream::ReadExactly
Read() can return fewer bytes than requested.
ReadExactly() will call Read() repeatedly until we
have read as many bytes as we need.

PiperOrigin-RevId: 518719418
2023-03-22 17:45:50 -07:00

120 lines
3.5 KiB
C++

// Copyright 2023 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "internal/platform/input_stream.h"
#include <string>
#include "gmock/gmock.h"
#include "protobuf-matchers/protocol-buffer-matchers.h"
#include "gtest/gtest.h"
#include "internal/platform/byte_array.h"
#include "internal/platform/exception.h"
namespace nearby {
namespace {
using ::testing::_;
using ::testing::InSequence;
using ::testing::NiceMock;
using ::testing::Return;
class TestInputStream : public InputStream {
public:
MOCK_METHOD(ExceptionOr<ByteArray>, Read, (std::int64_t), (override));
MOCK_METHOD(Exception, Close, (), (override));
};
// Returns a ByteArray with values: a, a + 1, a + 2, ..., b - 1.
ExceptionOr<ByteArray> Range(char a, char b) {
std::string s;
for (char c = a; c < b; c++) {
s.push_back(c);
}
return ExceptionOr<ByteArray>(ByteArray(s));
}
TEST(InputStreamTest, Skip) {
NiceMock<TestInputStream> stream;
InSequence seq;
EXPECT_CALL(stream, Read(50)).WillOnce(Return(Range(0, 10)));
EXPECT_CALL(stream, Read(40)).WillOnce(Return(Range(0, 10)));
EXPECT_CALL(stream, Read(30)).WillOnce(Return(Range(0, 30)));
ExceptionOr<std::size_t> skipped = stream.Skip(50);
EXPECT_EQ(skipped.result(), 50);
}
TEST(InputStreamTest, SkipsLessOnEof) {
NiceMock<TestInputStream> stream;
InSequence seq;
EXPECT_CALL(stream, Read(50)).WillOnce(Return(Range(0, 10)));
EXPECT_CALL(stream, Read(40)).WillOnce(Return(Range(0, 10)));
// Returns EOF
EXPECT_CALL(stream, Read(30)).WillOnce(Return(Range(0, 0)));
ExceptionOr<std::size_t> skipped = stream.Skip(50);
EXPECT_EQ(skipped.result(), 20);
}
TEST(InputStreamTest, SkipFailsOnError) {
NiceMock<TestInputStream> stream;
InSequence seq;
EXPECT_CALL(stream, Read(50)).WillOnce(Return(Range(0, 10)));
EXPECT_CALL(stream, Read(40))
.WillOnce(Return(ExceptionOr<ByteArray>(Exception::kIo)));
ExceptionOr<std::size_t> skipped = stream.Skip(50);
EXPECT_EQ(skipped.exception(), Exception::kIo);
}
TEST(InputStreamTest, ReadExactlyOneChunk) {
NiceMock<TestInputStream> stream;
EXPECT_CALL(stream, Read(10)).WillOnce(Return(Range(0, 10)));
ExceptionOr<ByteArray> result = stream.ReadExactly(10);
EXPECT_EQ(result, Range(0, 10));
}
TEST(InputStreamTest, ReadExactlyMultipleChunks) {
NiceMock<TestInputStream> stream;
InSequence seq;
EXPECT_CALL(stream, Read(30)).WillOnce(Return(Range(0, 10)));
EXPECT_CALL(stream, Read(20)).WillOnce(Return(Range(10, 20)));
EXPECT_CALL(stream, Read(10)).WillOnce(Return(Range(20, 30)));
ExceptionOr<ByteArray> result = stream.ReadExactly(30);
EXPECT_EQ(result, Range(0, 30));
}
TEST(InputStreamTest, ReadExactlyFailsOnError) {
NiceMock<TestInputStream> stream;
InSequence seq;
EXPECT_CALL(stream, Read(30)).WillOnce(Return(Range(0, 10)));
EXPECT_CALL(stream, Read(20))
.WillOnce(Return(ExceptionOr<ByteArray>(Exception::kIo)));
ExceptionOr<ByteArray> result = stream.ReadExactly(30);
EXPECT_EQ(result.exception(), Exception::kIo);
}
} // namespace
} // namespace nearby