libcamera: Break-out DeviceMatch

The DeviceMatch class is defined inside the 'device_enumerator'
file. Break it out to a dedicated file and header in order to expand
it to support multiple matching criteria.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

3 files changed, 93 insertions, 73 deletions

diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp
index f2e055de..49afd783 100644
--- a/src/libcamera/device_enumerator.cpp
+++ b/src/libcamera/device_enumerator.cpp
@@ -41,79 +41,6 @@ namespace libcamera {
 LOG_DEFINE_CATEGORY(DeviceEnumerator)
 
 /**
- * \class DeviceMatch
- * \brief Description of a media device search pattern
- *
- * The DeviceMatch class describes a media device using properties from the
- * Media Controller struct media_device_info, entity names in the media graph
- * or other properties that can be used to identify a media device.
- *
- * The description is meant to be filled by pipeline managers and passed to a
- * device enumerator to find matching media devices.
- *
- * A DeviceMatch is created with a specific Linux device driver in mind,
- * therefore the name of the driver is a required property. One or more Entity
- * names can be added as match criteria.
- *
- * Pipeline handlers are recommended to add entities to DeviceMatch as
- * appropriare to ensure that the media device they need can be uniquely
- * identified. This is useful when the corresponding kernel driver can produce
- * different graphs, for instance as a result of different driver versions or
- * hardware configurations, and not all those graphs are suitable for a pipeline
- * handler.
- */
-
-/**
- * \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)
-	: driver_(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)
-{
-	entities_.push_back(entity);
-}
-
-/**
- * \brief Compare a search pattern with a media device
- * \param[in] device The media device
- *
- * Matching is performed on the Linux device driver name and entity names from
- * the media graph. A match is found if both the driver name matches and the
- * media device contains all the entities listed in the search pattern.
- *
- * \return true if the media device matches the search pattern, false otherwise
- */
-bool DeviceMatch::match(const MediaDevice *device) const
-{
-	if (driver_ != device->driver())
-		return false;
-
-	for (const std::string &name : entities_) {
-		bool found = false;
-
-		for (const MediaEntity *entity : device->entities()) {
-			if (name == entity->name()) {
-				found = true;
-				break;
-			}
-		}
-
-		if (!found)
-			return false;
-	}
-
-	return true;
-}
-
-/**
  * \class DeviceEnumerator
  * \brief Enumerate, store and search media devices
  *
diff --git a/src/libcamera/device_match.cpp b/src/libcamera/device_match.cpp
new file mode 100644
index 00000000..a51b9081
--- /dev/null
+++ b/src/libcamera/device_match.cpp
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2023, Ideas On Board Oy
+ *
+ * device_match.cpp - Match and identify devices to create cameras with
+ */
+
+#include "libcamera/internal/device_match.h"
+
+#include "libcamera/internal/media_device.h"
+
+/**
+ * \file device_match.h
+ * \brief Define types and functions to identify devices used to create cameras
+ */
+
+namespace libcamera {
+
+/**
+ * \class DeviceMatch
+ * \brief Description of a media device search pattern
+ *
+ * The DeviceMatch class describes a media device using properties from the
+ * Media Controller struct media_device_info, entity names in the media graph
+ * or other properties that can be used to identify a media device.
+ *
+ * The description is meant to be filled by pipeline managers and passed to a
+ * device enumerator to find matching media devices.
+ *
+ * A DeviceMatch is created with a specific Linux device driver in mind,
+ * therefore the name of the driver is a required property. One or more Entity
+ * names can be added as match criteria.
+ *
+ * Pipeline handlers are recommended to add entities to DeviceMatch as
+ * appropriare to ensure that the media device they need can be uniquely
+ * identified. This is useful when the corresponding kernel driver can produce
+ * different graphs, for instance as a result of different driver versions or
+ * hardware configurations, and not all those graphs are suitable for a pipeline
+ * handler.
+ */
+
+/**
+ * \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)
+	: driver_(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)
+{
+	entities_.push_back(entity);
+}
+
+/**
+ * \brief Compare a search pattern with a media device
+ * \param[in] device The media device
+ *
+ * Matching is performed on the Linux device driver name and entity names from
+ * the media graph. A match is found if both the driver name matches and the
+ * media device contains all the entities listed in the search pattern.
+ *
+ * \return True if the media device matches the search pattern, false otherwise
+ */
+bool DeviceMatch::match(const MediaDevice *device) const
+{
+	if (driver_ != device->driver())
+		return false;
+
+	for (const std::string &name : entities_) {
+		bool found = false;
+
+		for (const MediaEntity *entity : device->entities()) {
+			if (name == entity->name()) {
+				found = true;
+				break;
+			}
+		}
+
+		if (!found)
+			return false;
+	}
+
+	return true;
+}
+
+} /* namespace libcamera */
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index b24f8296..d5562afc 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -17,6 +17,7 @@ libcamera_sources = files([
     'delayed_controls.cpp',
     'device_enumerator.cpp',
     'device_enumerator_sysfs.cpp',
+    'device_match.cpp',
     'fence.cpp',
     'formats.cpp',
     'framebuffer.cpp',