Userspace: Add simple AudioServer and LibAudio

userspace/libraries/LibAudio/Audio.cpp

@@ -0,0 +1,136 @@
+#include <BAN/ScopeGuard.h>
+
+#include <LibAudio/Audio.h>
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/banan-os.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+namespace LibAudio
+{
+
+	BAN::ErrorOr<Audio> Audio::load(BAN::StringView path)
+	{
+		Audio result(TRY(AudioLoader::load(path)));
+		TRY(result.initialize(256 * 1024));
+		return result;
+	}
+
+	BAN::ErrorOr<Audio> Audio::random(uint32_t samples)
+	{
+		Audio result;
+		TRY(result.initialize(samples));
+
+		result.m_audio_buffer->sample_rate = 48000;
+		result.m_audio_buffer->channels = 1;
+
+		for (size_t i = 0; i < samples - 1; i++)
+			result.m_audio_buffer->samples[i] = (rand() - RAND_MAX / 2) / (RAND_MAX / 2.0);
+		result.m_audio_buffer->head = samples - 1;
+
+		return result;
+	}
+
+	void Audio::clear()
+	{
+		if (m_audio_buffer)
+			munmap(m_audio_buffer, m_smo_size);
+		m_audio_buffer = nullptr;
+
+		if (m_smo_key != -1)
+			smo_delete(m_smo_key);
+		m_smo_key = -1;
+
+		if (m_server_fd != -1)
+			close(m_server_fd);
+		m_server_fd = -1;
+
+		m_audio_loader.clear();
+	}
+
+	Audio& Audio::operator=(Audio&& other)
+	{
+		clear();
+
+		m_server_fd    = other.m_server_fd;
+		m_smo_key      = other.m_smo_key;
+		m_smo_size     = other.m_smo_size;
+		m_audio_buffer = other.m_audio_buffer;
+		m_audio_loader = BAN::move(other.m_audio_loader);
+
+		other.m_server_fd    = -1;
+		other.m_smo_key      = -1;
+		other.m_smo_size     = 0;
+		other.m_audio_buffer = nullptr;
+
+		return *this;
+	}
+
+	BAN::ErrorOr<void> Audio::start()
+	{
+		ASSERT(m_server_fd != -1);
+
+		const ssize_t nsend = send(m_server_fd, &m_smo_key, sizeof(m_smo_key), 0);
+		if (nsend == -1)
+			return BAN::Error::from_errno(errno);
+		ASSERT(nsend == sizeof(m_smo_key));
+
+		return {};
+	}
+
+	BAN::ErrorOr<void> Audio::initialize(uint32_t total_samples)
+	{
+		m_smo_size = sizeof(AudioBuffer) + total_samples * sizeof(AudioBuffer::sample_t);
+
+		m_smo_key = smo_create(m_smo_size, PROT_READ | PROT_WRITE);
+		if (m_smo_key == -1)
+			return BAN::Error::from_errno(errno);
+
+		m_audio_buffer = static_cast<AudioBuffer*>(smo_map(m_smo_key));
+		if (m_audio_buffer == nullptr)
+			return BAN::Error::from_errno(errno);
+		new (m_audio_buffer) AudioBuffer();
+		memset(m_audio_buffer->samples, 0, total_samples * sizeof(AudioBuffer::sample_t));
+
+		m_audio_buffer->capacity = total_samples;
+		if (m_audio_loader)
+		{
+			m_audio_buffer->channels = m_audio_loader->channels();
+			m_audio_buffer->sample_rate = m_audio_loader->sample_rate();
+		}
+
+		update();
+
+		sockaddr_un server_addr;
+		server_addr.sun_family = AF_UNIX;
+		strcpy(server_addr.sun_path, s_audio_server_socket.data());
+
+		m_server_fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
+		if (m_server_fd == -1)
+			return BAN::Error::from_errno(errno);
+
+		if (connect(m_server_fd, reinterpret_cast<sockaddr*>(&server_addr), sizeof(server_addr)) == -1)
+			return BAN::Error::from_errno(errno);
+
+		return {};
+	}
+
+	void Audio::update()
+	{
+		if (!m_audio_loader)
+			return;
+
+		while (m_audio_loader->samples_remaining())
+		{
+			const uint32_t next_head = (m_audio_buffer->head + 1) % m_audio_buffer->capacity;
+			if (next_head == m_audio_buffer->tail)
+				break;
+			m_audio_buffer->samples[m_audio_buffer->head] = m_audio_loader->get_sample();
+			m_audio_buffer->head = next_head;
+		}
+	}
+
+}