From 5b0834f097896019b9938cd98d0693253ad0ca9b Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Sat, 8 Oct 2022 14:35:45 +0300
Subject: [PATCH] Support non-owning audio::recorder

---
 libs/audio/include/psemek/audio/recorder.hpp |  1 +
 libs/audio/source/recorder.cpp               | 36 ++++++++++++++------
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/libs/audio/include/psemek/audio/recorder.hpp b/libs/audio/include/psemek/audio/recorder.hpp
index d8f8fe33..f25b20e9 100644
--- a/libs/audio/include/psemek/audio/recorder.hpp
+++ b/libs/audio/include/psemek/audio/recorder.hpp
@@ -21,5 +21,6 @@ namespace psemek::audio
 
 	std::shared_ptr<recorder> make_recorder(stream_ptr stream);
 	std::shared_ptr<recorder> make_recorder(std::vector<float> samples);
+	std::shared_ptr<recorder> make_recorder(util::span<float const> samples);
 
 }
diff --git a/libs/audio/source/recorder.cpp b/libs/audio/source/recorder.cpp
index 18dbd25a..6300c914 100644
--- a/libs/audio/source/recorder.cpp
+++ b/libs/audio/source/recorder.cpp
@@ -16,13 +16,17 @@ namespace psemek::audio
 			{}
 
 			recorder_impl(std::vector<float> samples)
-				: buffer_(std::move(samples))
-				, length_(buffer_.size())
+				: storage_(std::move(samples))
+				, samples_(storage_)
+			{}
+
+			recorder_impl(util::span<float const> samples)
+				: samples_(samples)
 			{}
 
 			std::optional<std::size_t> length() const override
 			{
-				return stream_ ? stream_->length() : buffer_.size();
+				return stream_ ? stream_->length() : storage_.size();
 			}
 
 			std::size_t request(std::size_t samples) override
@@ -30,23 +34,26 @@ namespace psemek::audio
 				if (!stream_)
 					return 0;
 
-				if (buffer_.size() < length_ + samples)
-					buffer_.resize(std::max<std::size_t>(samples, buffer_.size() * 2));
+				if (storage_.size() < samples_.size() + samples)
+				{
+					storage_.resize(std::max<std::size_t>(samples, storage_.size() * 2));
+					samples_ = {storage_.data(), storage_.data() + samples_.size()};
+				}
 
-				auto result = stream_->read(buffer_.data() + length_, samples);
-				length_ += result;
+				auto result = stream_->read(storage_.data() + samples_.size(), samples);
+				samples_ = {storage_.data(), storage_.data() + samples_.size() + result};
 				return result;
 			}
 
 			util::span<float const> buffer() const override
 			{
-				return {buffer_.data(), buffer_.data() + length_};
+				return samples_;
 			}
 
 		private:
 			stream_ptr stream_;
-			std::vector<float> buffer_;
-			std::size_t length_{0};
+			std::vector<float> storage_;
+			util::span<float const> samples_;
 		};
 
 	}
@@ -58,7 +65,16 @@ namespace psemek::audio
 
 	std::shared_ptr<recorder> make_recorder(std::vector<float> samples)
 	{
+		if ((samples.size() % 2) != 0)
+			throw std::runtime_error("bad sample count");
 		return std::make_shared<recorder_impl>(std::move(samples));
 	}
 
+	std::shared_ptr<recorder> make_recorder(util::span<float const> samples)
+	{
+		if ((samples.size() % 2) != 0)
+			throw std::runtime_error("bad sample count");
+		return std::make_shared<recorder_impl>(samples);
+	}
+
 }