pw_stream: Create module
pw_stream provides a generic writer interface that allows modules to
write data without assuming anything about what the data is written to.
A pw::stream::Writer could be backed by RAM, flash memory, or just pipe
the data out over a communication channel.
Change-Id: Ie8f8a66819a2c80a47f7cc75e2c9d1bbe25a668d
diff --git a/pw_stream/memory_stream.cc b/pw_stream/memory_stream.cc
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+++ b/pw_stream/memory_stream.cc
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+// Copyright 2020 The Pigweed Authors
+//
+// 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 "pw_stream/memory_stream.h"
+
+#include <cstddef>
+#include <cstring>
+
+#include "pw_status/status_with_size.h"
+
+namespace pw::stream {
+
+Status MemoryWriter::DoWrite(span<const std::byte> data) {
+ size_t bytes_to_write =
+ std::min(data.size_bytes(), dest_.size_bytes() - bytes_written_);
+ std::memcpy(dest_.data() + bytes_written_, data.data(), bytes_to_write);
+ bytes_written_ += bytes_to_write;
+
+ if (bytes_to_write != data.size_bytes()) {
+ return Status::RESOURCE_EXHAUSTED;
+ }
+ return Status::OK;
+}
+
+} // namespace pw::stream
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