[RFC,6/8] libcamera: Update string usage in internal APIs

22326 diff mbox series

diff --git a/include/libcamera/internal/camera_sensor_properties.h b/include/libcamera/internal/camera_sensor_properties.h
index d7d4dab626df7b82..b44093906d6390c0 100644
--- a/include/libcamera/internal/camera_sensor_properties.h
+++ b/include/libcamera/internal/camera_sensor_properties.h
@@ -9,7 +9,7 @@ 
 
 #include <map>
 #include <stdint.h>
-#include <string>
+#include <string_view>
 
 #include <libcamera/control_ids.h>
 #include <libcamera/geometry.h>
@@ -24,7 +24,7 @@  struct CameraSensorProperties {
 		uint8_t hblankDelay;
 	};
 
-	static const CameraSensorProperties *get(const std::string &sensor);
+	static const CameraSensorProperties *get(std::string_view sensor);
 
 	Size unitCellSize;
 	std::map<controls::draft::TestPatternModeEnum, int32_t> testPatternModes;
diff --git a/include/libcamera/internal/converter.h b/include/libcamera/internal/converter.h
index ffbb6f345cd5ed4f..fb8d81898e90bcb8 100644
--- a/include/libcamera/internal/converter.h
+++ b/include/libcamera/internal/converter.h
@@ -13,6 +13,7 @@ 
 #include <map>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <tuple>
 #include <utility>
 #include <vector>
@@ -44,7 +45,7 @@  public:
 	Converter(MediaDevice *media, Features features = Feature::None);
 	virtual ~Converter();
 
-	virtual int loadConfiguration(const std::string &filename) = 0;
+	virtual int loadConfiguration(std::string_view filename) = 0;
 
 	virtual bool isValid() const = 0;
 
diff --git a/include/libcamera/internal/converter/converter_v4l2_m2m.h b/include/libcamera/internal/converter/converter_v4l2_m2m.h
index 0bc0d053e2c47d3a..5475cc6b3ac58b30 100644
--- a/include/libcamera/internal/converter/converter_v4l2_m2m.h
+++ b/include/libcamera/internal/converter/converter_v4l2_m2m.h
@@ -11,7 +11,6 @@ 
 #include <functional>
 #include <map>
 #include <memory>
-#include <string>
 #include <tuple>
 #include <vector>
 
@@ -38,7 +37,7 @@  class V4L2M2MConverter : public Converter
 public:
 	V4L2M2MConverter(MediaDevice *media);
 
-	int loadConfiguration([[maybe_unused]] const std::string &filename) { return 0; }
+	int loadConfiguration([[maybe_unused]] std::string_view filename) { return 0; }
 	bool isValid() const { return m2m_ != nullptr; }
 
 	std::vector<PixelFormat> formats(PixelFormat input);
diff --git a/include/libcamera/internal/device_enumerator.h b/include/libcamera/internal/device_enumerator.h
index db3532a9887af913..c3a09f03433729c4 100644
--- a/include/libcamera/internal/device_enumerator.h
+++ b/include/libcamera/internal/device_enumerator.h
@@ -20,9 +20,9 @@  class MediaDevice;
 class DeviceMatch
 {
 public:
-	DeviceMatch(const std::string &driver);
+	DeviceMatch(std::string_view driver);
 
-	void add(const std::string &entity);
+	void add(std::string_view entity);
 
 	bool match(const MediaDevice *device) const;
 
@@ -46,9 +46,9 @@  public:
 	Signal<> devicesAdded;
 
 protected:
-	std::unique_ptr<MediaDevice> createDevice(const std::string &deviceNode);
+	std::unique_ptr<MediaDevice> createDevice(std::string_view deviceNode);
 	void addDevice(std::unique_ptr<MediaDevice> media);
-	void removeDevice(const std::string &deviceNode);
+	void removeDevice(std::string_view deviceNode);
 
 private:
 	std::vector<std::shared_ptr<MediaDevice>> devices_;
diff --git a/include/libcamera/internal/formats.h b/include/libcamera/internal/formats.h
index 6a3e9c16a873e969..bd7ac6ed128f594b 100644
--- a/include/libcamera/internal/formats.h
+++ b/include/libcamera/internal/formats.h
@@ -8,6 +8,7 @@ 
 #pragma once
 
 #include <array>
+#include <string_view>
 #include <vector>
 
 #include <libcamera/geometry.h>
@@ -35,7 +36,7 @@  public:
 
 	static const PixelFormatInfo &info(const PixelFormat &format);
 	static const PixelFormatInfo &info(const V4L2PixelFormat &format);
-	static const PixelFormatInfo &info(const std::string &name);
+	static const PixelFormatInfo &info(std::string_view name);
 
 	unsigned int stride(unsigned int width, unsigned int plane,
 			    unsigned int align = 1) const;
diff --git a/include/libcamera/internal/ipa_module.h b/include/libcamera/internal/ipa_module.h
index 7c49d3f342e5055c..5f7c7e6e9f6987a0 100644
--- a/include/libcamera/internal/ipa_module.h
+++ b/include/libcamera/internal/ipa_module.h
@@ -9,6 +9,7 @@ 
 
 #include <stdint.h>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <libcamera/base/log.h>
@@ -23,7 +24,7 @@  namespace libcamera {
 class IPAModule : public Loggable
 {
 public:
-	explicit IPAModule(const std::string &libPath);
+	explicit IPAModule(std::string_view libPath);
 	~IPAModule();
 
 	bool isValid() const;
diff --git a/include/libcamera/internal/ipa_proxy.h b/include/libcamera/internal/ipa_proxy.h
index 983bcc5faa4bab3b..93b3b991f8d4b80e 100644
--- a/include/libcamera/internal/ipa_proxy.h
+++ b/include/libcamera/internal/ipa_proxy.h
@@ -8,6 +8,7 @@ 
 #pragma once
 
 #include <string>
+#include <string_view>
 
 #include <libcamera/ipa/ipa_interface.h>
 
@@ -29,11 +30,11 @@  public:
 
 	bool isValid() const { return valid_; }
 
-	std::string configurationFile(const std::string &name,
-				      const std::string &fallbackName = std::string()) const;
+	std::string configurationFile(std::string_view name,
+				      std::string_view fallbackName = {}) const;
 
 protected:
-	std::string resolvePath(const std::string &file) const;
+	std::string resolvePath(std::string_view file) const;
 
 	bool valid_;
 	ProxyState state_;
diff --git a/include/libcamera/internal/media_device.h b/include/libcamera/internal/media_device.h
index e412d3a0b7e38cd3..1882b9aeb87f533a 100644
--- a/include/libcamera/internal/media_device.h
+++ b/include/libcamera/internal/media_device.h
@@ -9,6 +9,7 @@ 
 
 #include <map>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <linux/media.h>
@@ -24,7 +25,7 @@  namespace libcamera {
 class MediaDevice : protected Loggable
 {
 public:
-	MediaDevice(const std::string &deviceNode);
+	MediaDevice(std::string_view deviceNode);
 	~MediaDevice();
 
 	bool acquire();
@@ -44,10 +45,10 @@  public:
 	unsigned int hwRevision() const { return hwRevision_; }
 
 	const std::vector<MediaEntity *> &entities() const { return entities_; }
-	MediaEntity *getEntityByName(const std::string &name) const;
+	MediaEntity *getEntityByName(std::string_view name) const;
 
-	MediaLink *link(const std::string &sourceName, unsigned int sourceIdx,
-			const std::string &sinkName, unsigned int sinkIdx);
+	MediaLink *link(std::string_view sourceName, unsigned int sourceIdx,
+			std::string_view sinkName, unsigned int sinkIdx);
 	MediaLink *link(const MediaEntity *source, unsigned int sourceIdx,
 			const MediaEntity *sink, unsigned int sinkIdx);
 	MediaLink *link(const MediaPad *source, const MediaPad *sink);
diff --git a/include/libcamera/internal/pipeline_handler.h b/include/libcamera/internal/pipeline_handler.h
index fb28a18d0f4668ab..f91d1c6cba842f49 100644
--- a/include/libcamera/internal/pipeline_handler.h
+++ b/include/libcamera/internal/pipeline_handler.h
@@ -10,6 +10,7 @@ 
 #include <memory>
 #include <queue>
 #include <string>
+#include <string_view>
 #include <sys/types.h>
 #include <vector>
 
@@ -62,8 +63,8 @@  public:
 	void completeRequest(Request *request);
 	void cancelRequest(Request *request);
 
-	std::string configurationFile(const std::string &subdir,
-				      const std::string &name) const;
+	std::string configurationFile(std::string_view subdir,
+				      std::string_view name) const;
 
 	const char *name() const { return name_; }
 
@@ -112,7 +113,7 @@  public:
 	const std::string &name() const { return name_; }
 
 	static std::vector<PipelineHandlerFactoryBase *> &factories();
-	static const PipelineHandlerFactoryBase *getFactoryByName(const std::string &name);
+	static const PipelineHandlerFactoryBase *getFactoryByName(std::string_view name);
 
 private:
 	static void registerType(PipelineHandlerFactoryBase *factory);
diff --git a/include/libcamera/internal/software_isp/software_isp.h b/include/libcamera/internal/software_isp/software_isp.h
index d51b03fd6cd71fce..bc4eb36260e93fbc 100644
--- a/include/libcamera/internal/software_isp/software_isp.h
+++ b/include/libcamera/internal/software_isp/software_isp.h
@@ -12,7 +12,7 @@ 
 #include <map>
 #include <memory>
 #include <stdint.h>
-#include <string>
+#include <string_view>
 #include <tuple>
 #include <vector>
 
@@ -50,7 +50,7 @@  public:
 		    ControlInfoMap *ipaControls);
 	~SoftwareIsp();
 
-	int loadConfiguration([[maybe_unused]] const std::string &filename) { return 0; }
+	int loadConfiguration([[maybe_unused]] std::string_view filename) { return 0; }
 
 	bool isValid() const;
 
diff --git a/include/libcamera/internal/sysfs.h b/include/libcamera/internal/sysfs.h
index aca60fb6c8ab9a2c..db78d790f3ff23bd 100644
--- a/include/libcamera/internal/sysfs.h
+++ b/include/libcamera/internal/sysfs.h
@@ -8,6 +8,7 @@ 
 #pragma once
 
 #include <string>
+#include <string_view>
 
 namespace libcamera {
 
@@ -15,7 +16,7 @@  namespace sysfs {
 
 std::string charDevPath(const std::string &deviceNode);
 
-std::string firmwareNodePath(const std::string &device);
+std::string firmwareNodePath(std::string_view device);
 
 } /* namespace sysfs */
 
diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h
index f5aa502482017325..623403dc615ea604 100644
--- a/include/libcamera/internal/v4l2_device.h
+++ b/include/libcamera/internal/v4l2_device.h
@@ -10,6 +10,7 @@ 
 #include <map>
 #include <memory>
 #include <optional>
+#include <string_view>
 #include <vector>
 
 #include <linux/videodev2.h>
@@ -50,7 +51,7 @@  public:
 	void updateControlInfo();
 
 protected:
-	V4L2Device(const std::string &deviceNode);
+	V4L2Device(std::string_view deviceNode);
 	~V4L2Device();
 
 	int open(unsigned int flags);
diff --git a/include/libcamera/internal/v4l2_subdevice.h b/include/libcamera/internal/v4l2_subdevice.h
index 194382f84d97fbbc..d17365e14a231df3 100644
--- a/include/libcamera/internal/v4l2_subdevice.h
+++ b/include/libcamera/internal/v4l2_subdevice.h
@@ -11,6 +11,7 @@ 
 #include <optional>
 #include <ostream>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <linux/v4l2-subdev.h>
@@ -161,7 +162,7 @@  public:
 	const V4L2SubdeviceCapability &caps() const { return caps_; }
 
 	static std::unique_ptr<V4L2Subdevice>
-	fromEntityName(const MediaDevice *media, const std::string &entity);
+	fromEntityName(const MediaDevice *media, std::string_view entity);
 
 protected:
 	std::string logPrefix() const override;
diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h
index f021c2a0177b4512..45443ed716d7f6f2 100644
--- a/include/libcamera/internal/v4l2_videodevice.h
+++ b/include/libcamera/internal/v4l2_videodevice.h
@@ -14,6 +14,7 @@ 
 #include <ostream>
 #include <stdint.h>
 #include <string>
+#include <string_view>
 #include <unordered_set>
 #include <vector>
 
@@ -189,7 +190,7 @@  class V4L2VideoDevice : public V4L2Device
 public:
 	using Formats = std::map<V4L2PixelFormat, std::vector<SizeRange>>;
 
-	explicit V4L2VideoDevice(const std::string &deviceNode);
+	explicit V4L2VideoDevice(std::string_view deviceNode);
 	explicit V4L2VideoDevice(const MediaEntity *entity);
 	~V4L2VideoDevice();
 
@@ -228,7 +229,7 @@  public:
 	Signal<> dequeueTimeout;
 
 	static std::unique_ptr<V4L2VideoDevice>
-	fromEntityName(const MediaDevice *media, const std::string &entity);
+	fromEntityName(const MediaDevice *media, std::string_view entity);
 
 	V4L2PixelFormat toV4L2PixelFormat(const PixelFormat &pixelFormat) const;
 
@@ -295,7 +296,7 @@  private:
 class V4L2M2MDevice
 {
 public:
-	V4L2M2MDevice(const std::string &deviceNode);
+	V4L2M2MDevice(std::string_view deviceNode);
 	~V4L2M2MDevice();
 
 	int open();
diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp
index ae17862f676310ef..1efc5b33639f6af8 100644
--- a/src/libcamera/device_enumerator.cpp
+++ b/src/libcamera/device_enumerator.cpp
@@ -67,7 +67,7 @@  LOG_DEFINE_CATEGORY(DeviceEnumerator)
  * \brief Construct a media device search pattern
  * \param[in] driver The Linux device driver name that created the media device
  */
-DeviceMatch::DeviceMatch(const std::string &driver)
+DeviceMatch::DeviceMatch(std::string_view driver)
 	: driver_(driver)
 {
 }
@@ -76,9 +76,9 @@  DeviceMatch::DeviceMatch(const std::string &driver)
  * \brief Add a media entity name to the search pattern
  * \param[in] entity The name of the entity in the media graph
  */
-void DeviceMatch::add(const std::string &entity)
+void DeviceMatch::add(std::string_view entity)
 {
-	entities_.push_back(entity);
+	entities_.push_back(std::string(entity));
 }
 
 /**
@@ -215,7 +215,7 @@  DeviceEnumerator::~DeviceEnumerator()
  *
  * \return Created media device instance on success, or nullptr otherwise
  */
-std::unique_ptr<MediaDevice> DeviceEnumerator::createDevice(const std::string &deviceNode)
+std::unique_ptr<MediaDevice> DeviceEnumerator::createDevice(std::string_view deviceNode)
 {
 	std::unique_ptr<MediaDevice> media = std::make_unique<MediaDevice>(deviceNode);
 
@@ -272,7 +272,7 @@  void DeviceEnumerator::addDevice(std::unique_ptr<MediaDevice> media)
  * enumerator with addDevice(). The media device's MediaDevice::disconnected
  * signal is emitted.
  */
-void DeviceEnumerator::removeDevice(const std::string &deviceNode)
+void DeviceEnumerator::removeDevice(std::string_view deviceNode)
 {
 	std::shared_ptr<MediaDevice> media;
 
diff --git a/src/libcamera/formats.cpp b/src/libcamera/formats.cpp
index bfcdfc08960dbbad..112dfe66b4747516 100644
--- a/src/libcamera/formats.cpp
+++ b/src/libcamera/formats.cpp
@@ -1037,7 +1037,7 @@  const PixelFormatInfo &PixelFormatInfo::info(const V4L2PixelFormat &format)
  * \return The PixelFormatInfo describing the PixelFormat matching the
  * \a name if known, or an invalid PixelFormatInfo otherwise
  */
-const PixelFormatInfo &PixelFormatInfo::info(const std::string &name)
+const PixelFormatInfo &PixelFormatInfo::info(std::string_view name)
 {
 	for (const auto &info : pixelFormatInfo) {
 		if (info.second.name == name)
diff --git a/src/libcamera/ipa_module.cpp b/src/libcamera/ipa_module.cpp
index 9ca74be6e100a8fa..90e3148d236f3a3c 100644
--- a/src/libcamera/ipa_module.cpp
+++ b/src/libcamera/ipa_module.cpp
@@ -254,7 +254,7 @@  Span<const uint8_t> elfLoadSymbol(Span<const uint8_t> elf, const char *symbol)
  * The caller shall call the isValid() function after constructing an
  * IPAModule instance to verify the validity of the IPAModule.
  */
-IPAModule::IPAModule(const std::string &libPath)
+IPAModule::IPAModule(std::string_view libPath)
 	: libPath_(libPath), valid_(false), loaded_(false),
 	  dlHandle_(nullptr), ipaCreate_(nullptr)
 {
diff --git a/src/libcamera/ipa_proxy.cpp b/src/libcamera/ipa_proxy.cpp
index 85004737c17100bf..a06bd94ff435021e 100644
--- a/src/libcamera/ipa_proxy.cpp
+++ b/src/libcamera/ipa_proxy.cpp
@@ -95,8 +95,8 @@  IPAProxy::~IPAProxy()
  * \return The full path to the IPA configuration file, or an empty string if
  * no configuration file can be found
  */
-std::string IPAProxy::configurationFile(const std::string &name,
-					const std::string &fallbackName) const
+std::string IPAProxy::configurationFile(std::string_view name,
+					std::string_view fallbackName) const
 {
 	struct stat statbuf;
 	int ret;
@@ -178,9 +178,9 @@  std::string IPAProxy::configurationFile(const std::string &name,
  * \return The full path to the proxy worker executable, or an empty string if
  * no valid executable path
  */
-std::string IPAProxy::resolvePath(const std::string &file) const
+std::string IPAProxy::resolvePath(std::string_view file) const
 {
-	std::string proxyFile = "/" + file;
+	std::string proxyFile = std::string("/") + file;
 
 	/* Check env variable first. */
 	const char *execPaths = utils::secure_getenv("LIBCAMERA_IPA_PROXY_PATH");
diff --git a/src/libcamera/media_device.cpp b/src/libcamera/media_device.cpp
index d71dad74df70d1fc..34f2a78fcc287066 100644
--- a/src/libcamera/media_device.cpp
+++ b/src/libcamera/media_device.cpp
@@ -62,7 +62,7 @@  LOG_DEFINE_CATEGORY(MediaDevice)
  * Once constructed the media device is invalid, and must be populated with
  * populate() before the media graph can be queried.
  */
-MediaDevice::MediaDevice(const std::string &deviceNode)
+MediaDevice::MediaDevice(std::string_view deviceNode)
 	: deviceNode_(deviceNode), valid_(false), acquired_(false)
 {
 }
@@ -331,7 +331,7 @@  done:
  * \param[in] name The entity name
  * \return The entity with \a name, or nullptr if no such entity is found
  */
-MediaEntity *MediaDevice::getEntityByName(const std::string &name) const
+MediaEntity *MediaDevice::getEntityByName(std::string_view name) const
 {
 	for (MediaEntity *e : entities_)
 		if (e->name() == name)
@@ -359,8 +359,8 @@  MediaEntity *MediaDevice::getEntityByName(const std::string &name) const
  * \return The link that connects the two pads, or nullptr if no such a link
  * exists
  */
-MediaLink *MediaDevice::link(const std::string &sourceName, unsigned int sourceIdx,
-			     const std::string &sinkName, unsigned int sinkIdx)
+MediaLink *MediaDevice::link(std::string_view sourceName, unsigned int sourceIdx,
+			     std::string_view sinkName, unsigned int sinkIdx)
 {
 	const MediaEntity *source = getEntityByName(sourceName);
 	const MediaEntity *sink = getEntityByName(sinkName);
@@ -382,8 +382,8 @@  MediaLink *MediaDevice::link(const std::string &sourceName, unsigned int sourceI
  * entity \a source, to the pad at index \a sinkIdx of the sink entity \a
  * sink, if any.
  *
- * \sa link(const std::string &sourceName, unsigned int sourceIdx,
- *          const std::string &sinkName, unsigned int sinkIdx)
+ * \sa link(std::string_view sourceName, unsigned int sourceIdx,
+ *          std::string_view sinkName, unsigned int sinkIdx)
  * \sa link(const MediaPad *source, const MediaPad *sink)
  *
  * \return The link that connects the two pads, or nullptr if no such a link
@@ -406,8 +406,8 @@  MediaLink *MediaDevice::link(const MediaEntity *source, unsigned int sourceIdx,
  * \param[in] source The source pad
  * \param[in] sink The sink pad
  *
- * \sa link(const std::string &sourceName, unsigned int sourceIdx,
- *          const std::string &sinkName, unsigned int sinkIdx)
+ * \sa link(std::string_view sourceName, unsigned int sourceIdx,
+ *          std::string_view sinkName, unsigned int sinkIdx)
  * \sa link(const MediaEntity *source, unsigned int sourceIdx,
  *          const MediaEntity *sink, unsigned int sinkIdx)
  *
diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
index 8c2c6baf35751d64..51a32316b7008790 100644
--- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
@@ -12,6 +12,7 @@ 
 #include <memory>
 #include <set>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <libcamera/base/log.h>
@@ -571,7 +572,7 @@  bool UVCCameraData::generateId()
 
 	/* Create a controller ID from first device described in firmware. */
 	std::string controllerId;
-	std::string searchPath = path;
+	std::string_view searchPath{ path };
 	while (true) {
 		std::string::size_type pos = searchPath.rfind('/');
 		if (pos <= 1) {
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index caa5c20e74836956..4cf9e8256503efac 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -595,8 +595,8 @@  void PipelineHandler::cancelRequest(Request *request)
  * \return The full path to the pipeline handler configuration file, or an empty
  * string if no configuration file can be found
  */
-std::string PipelineHandler::configurationFile(const std::string &subdir,
-					       const std::string &name) const
+std::string PipelineHandler::configurationFile(std::string_view subdir,
+					       std::string_view name) const
 {
 	std::string confPath;
 	struct stat statbuf;
@@ -852,7 +852,7 @@  std::vector<PipelineHandlerFactoryBase *> &PipelineHandlerFactoryBase::factories
  * \param[in] name The pipeline handler name
  * \return The factory of the pipeline with name \a name, or nullptr if not found
  */
-const PipelineHandlerFactoryBase *PipelineHandlerFactoryBase::getFactoryByName(const std::string &name)
+const PipelineHandlerFactoryBase *PipelineHandlerFactoryBase::getFactoryByName(std::string_view name)
 {
 	const std::vector<PipelineHandlerFactoryBase *> &factories =
 		PipelineHandlerFactoryBase::factories();
diff --git a/src/libcamera/sensor/camera_sensor_properties.cpp b/src/libcamera/sensor/camera_sensor_properties.cpp
index 2b06c5a1a5d15abd..4283cacfa5e0b44a 100644
--- a/src/libcamera/sensor/camera_sensor_properties.cpp
+++ b/src/libcamera/sensor/camera_sensor_properties.cpp
@@ -78,9 +78,9 @@  LOG_DEFINE_CATEGORY(CameraSensorProperties)
  * \return A pointer to the CameraSensorProperties instance associated with a sensor
  * or nullptr if the sensor is not supported
  */
-const CameraSensorProperties *CameraSensorProperties::get(const std::string &sensor)
+const CameraSensorProperties *CameraSensorProperties::get(std::string_view sensor)
 {
-	static const std::map<std::string, const CameraSensorProperties> sensorProps = {
+	static const std::map<std::string_view, const CameraSensorProperties> sensorProps = {
 		{ "ar0144", {
 			.unitCellSize = { 3000, 3000 },
 			.testPatternModes = {
diff --git a/src/libcamera/software_isp/software_isp.cpp b/src/libcamera/software_isp/software_isp.cpp
index 2bea64d9f9947e09..5ca215ed4d5c6abc 100644
--- a/src/libcamera/software_isp/software_isp.cpp
+++ b/src/libcamera/software_isp/software_isp.cpp
@@ -9,6 +9,7 @@ 
 
 #include <cmath>
 #include <stdint.h>
+#include <string>
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -148,7 +149,7 @@  SoftwareIsp::~SoftwareIsp()
 }
 
 /**
- * \fn int SoftwareIsp::loadConfiguration([[maybe_unused]] const std::string &filename)
+ * \fn int SoftwareIsp::loadConfiguration([[maybe_unused]] std::string_view filename)
  * \brief Load a configuration from a file
  * \param[in] filename The file to load the configuration data from
  *
diff --git a/src/libcamera/sysfs.cpp b/src/libcamera/sysfs.cpp
index cbde72d86fd62b41..c1e2b0494e35d6bb 100644
--- a/src/libcamera/sysfs.cpp
+++ b/src/libcamera/sysfs.cpp
@@ -15,6 +15,8 @@ 
 #include <libcamera/base/file.h>
 #include <libcamera/base/log.h>
 
+using namespace std::literals::string_literals;
+
 /**
  * \file sysfs.h
  * \brief Miscellaneous utility functions to access sysfs
@@ -67,13 +69,13 @@  std::string charDevPath(const std::string &deviceNode)
  *
  * \return The firmware node path on success or an empty string on failure
  */
-std::string firmwareNodePath(const std::string &device)
+std::string firmwareNodePath(std::string_view device)
 {
 	std::string fwPath, node;
 	struct stat st;
 
 	/* Lookup for DT-based systems */
-	node = device + "/of_node";
+	node = device + "/of_node"s;
 	if (!stat(node.c_str(), &st)) {
 		char *ofPath = realpath(node.c_str(), nullptr);
 		if (!ofPath)
@@ -91,7 +93,7 @@  std::string firmwareNodePath(const std::string &device)
 	}
 
 	/* Lookup for ACPI-based systems */
-	node = device + "/firmware_node/path";
+	node = device + "/firmware_node/path"s;
 	if (File::exists(node.c_str())) {
 		std::ifstream file(node);
 		if (!file.is_open())
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 664b74afe6a12757..a8eda2d84357d355 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -56,7 +56,7 @@  LOG_DEFINE_CATEGORY(V4L2)
  * Initialize the file descriptor to -1 and store the \a deviceNode to be used
  * at open() time, and the \a logTag to prefix log messages with.
  */
-V4L2Device::V4L2Device(const std::string &deviceNode)
+V4L2Device::V4L2Device(std::string_view deviceNode)
 	: deviceNode_(deviceNode), fdEventNotifier_(nullptr),
 	  frameStartEnabled_(false)
 {
diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
index 3a0d075f93c457d1..fece69e575b718e1 100644
--- a/src/libcamera/v4l2_subdevice.cpp
+++ b/src/libcamera/v4l2_subdevice.cpp
@@ -1687,8 +1687,7 @@  const std::string &V4L2Subdevice::model()
  * \return A newly created V4L2Subdevice on success, nullptr otherwise
  */
 std::unique_ptr<V4L2Subdevice>
-V4L2Subdevice::fromEntityName(const MediaDevice *media,
-			      const std::string &entity)
+V4L2Subdevice::fromEntityName(const MediaDevice *media, std::string_view entity)
 {
 	MediaEntity *mediaEntity = media->getEntityByName(entity);
 	if (!mediaEntity)
diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
index a5cf67845ce3600b..91891ffb1590d5b0 100644
--- a/src/libcamera/v4l2_videodevice.cpp
+++ b/src/libcamera/v4l2_videodevice.cpp
@@ -531,7 +531,7 @@  std::ostream &operator<<(std::ostream &out, const V4L2DeviceFormat &f)
  * \brief Construct a V4L2VideoDevice
  * \param[in] deviceNode The file-system path to the video device node
  */
-V4L2VideoDevice::V4L2VideoDevice(const std::string &deviceNode)
+V4L2VideoDevice::V4L2VideoDevice(std::string_view deviceNode)
 	: V4L2Device(deviceNode), formatInfo_(nullptr), cache_(nullptr),
 	  fdBufferNotifier_(nullptr), state_(State::Stopped),
 	  watchdogDuration_(0.0)
@@ -2076,8 +2076,7 @@  void V4L2VideoDevice::watchdogExpired()
  * \return A newly created V4L2VideoDevice on success, nullptr otherwise
  */
 std::unique_ptr<V4L2VideoDevice>
-V4L2VideoDevice::fromEntityName(const MediaDevice *media,
-				const std::string &entity)
+V4L2VideoDevice::fromEntityName(const MediaDevice *media, std::string_view entity)
 {
 	MediaEntity *mediaEntity = media->getEntityByName(entity);
 	if (!mediaEntity)
@@ -2160,7 +2159,7 @@  V4L2PixelFormat V4L2VideoDevice::toV4L2PixelFormat(const PixelFormat &pixelForma
  * \brief Create a new V4L2M2MDevice from the \a deviceNode
  * \param[in] deviceNode The file-system path to the video device node
  */
-V4L2M2MDevice::V4L2M2MDevice(const std::string &deviceNode)
+V4L2M2MDevice::V4L2M2MDevice(std::string_view deviceNode)
 	: deviceNode_(deviceNode)
 {
 	output_ = new V4L2VideoDevice(deviceNode);