Move stream implementation to its own file.

internal/platform/implementation/linux/stream.cc

@@ -0,0 +1,76 @@
+// 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 <unistd.h>
+#include <array>
+#include <cerrno>
+#include <cstdint>
+
+#include "internal/platform/byte_array.h"
+#include "internal/platform/exception.h"
+#include "internal/platform/implementation/linux/stream.h"
+
+namespace nearby {
+namespace linux {
+
+ExceptionOr<ByteArray> InputStream::Read(std::int64_t size) {
+  if (!fd_.isValid()) return {Exception::kIo};
+
+  std::string buffer;
+  buffer.resize(size);
+  ssize_t ret = read(fd_.get(), buffer.data(), buffer.size());
+  if (ret == 0) {
+    return ExceptionOr(ByteArray());
+  }
+  if (ret < 0) {
+    return {Exception::kIo};
+  }
+  buffer.resize(ret);
+
+  return ExceptionOr(ByteArray(std::move(buffer)));
+}
+
+Exception InputStream::Close() {
+  if (!fd_.isValid()) return Exception{Exception::kIo};
+  fd_.reset();
+  return {};
+}
+
+Exception OutputStream::Write(const ByteArray &data) {
+  if (!fd_.isValid()) return Exception{Exception::kIo};
+
+  size_t written = 0;
+  while (written < data.size()) {
+    ssize_t ret = write(fd_.get(), data.data(), data.size());
+    if (ret < 1) {
+      return Exception{Exception::kIo};
+    }
+    written += ret;
+  }
+  return Exception{Exception::kSuccess};
+}
+
+Exception OutputStream::Flush() { return Exception{Exception::kSuccess}; }
+
+Exception OutputStream::Close() {
+  if (!fd_.isValid()) return Exception{Exception::kIo};
+
+  auto ret = close(fd_.get()) < 0 ? Exception{Exception::kIo}
+                                   : Exception{Exception::kSuccess};
+  fd_.reset();
+  return ret;
+}
+
+}  // namespace linux
+}  // namespace nearby