[libcamera-devel] [PATCH v3 3/6] libcamera: ipa_manager: Allow recursive parsing

[Kieran Bingham]

Provide an optional means to recurse into subdirectories to search for IPA
libraries. This allows IPAs contained within their own build directory
to be resolved when loading from a non-installed build.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 src/libcamera/include/ipa_manager.h |  6 ++-
 src/libcamera/ipa_manager.cpp       | 69 ++++++++++++++++++++++-------
 2 files changed, 58 insertions(+), 17 deletions(-)

diff --git a/src/libcamera/include/ipa_manager.h b/src/libcamera/include/ipa_manager.h
index 94d35d9062e4..5dca2c2a7d8d 100644
--- a/src/libcamera/include/ipa_manager.h
+++ b/src/libcamera/include/ipa_manager.h
@@ -32,8 +32,10 @@ private:
 	IPAManager();
 	~IPAManager();
 
-	int addDir(const char *libDir);
-	int addPath(const char *path);
+	int parseDir(const char *libDir, std::vector<std::string> &files,
+		     unsigned int maxDepth);
+	int addDir(const char *libDir, unsigned int maxDepth = 0);
+	int addPath(const char *path, unsigned int maxDepth = 0);
 };
 
 } /* namespace libcamera */
diff --git a/src/libcamera/ipa_manager.cpp b/src/libcamera/ipa_manager.cpp
index d87f2221b00b..c30b4555290f 100644
--- a/src/libcamera/ipa_manager.cpp
+++ b/src/libcamera/ipa_manager.cpp
@@ -140,16 +140,20 @@ IPAManager *IPAManager::instance()
 }
 
 /**
- * \brief Load IPA modules from a directory
- * \param[in] libDir directory to search for IPA modules
+ * \brief Identify shared library objects within a directory
+ * \param[in] libDir The directory to search for IPA modules
+ * \param[in] files A vector of paths to shared object library files
+ * \param[in] maxDepth The maximum depth of sub-directories to parse
  *
- * This method tries to create an IPAModule instance for every shared object
- * found in \a libDir, and skips invalid IPA modules.
+ * Search a directory for .so files, allowing recursion down to
+ * subdirectories no further than the depth specified by \a maxDepth.
  *
- * \return Number of modules loaded by this call, or a negative error code
- * otherwise
+ * Discovered shared objects are added to the files vector.
+ *
+ * \return 0 on success or a negative error code otherwise
  */
-int IPAManager::addDir(const char *libDir)
+int IPAManager::parseDir(const char *libDir, std::vector<std::string> &files,
+			 unsigned int maxDepth)
 {
 	struct dirent *ent;
 	DIR *dir;
@@ -158,30 +162,64 @@ int IPAManager::addDir(const char *libDir)
 	if (!dir)
 		return -errno;
 
-	std::vector<std::string> paths;
 	while ((ent = readdir(dir)) != nullptr) {
+		if (ent->d_type == DT_DIR && maxDepth) {
+			if (strcmp(ent->d_name, ".") == 0 ||
+			    strcmp(ent->d_name, "..") == 0)
+				continue;
+
+			std::string subdir = std::string(libDir) + "/" + ent->d_name;
+
+			/* Recursion is limited to maxDepth. */
+			parseDir(subdir.c_str(), files, maxDepth - 1);
+
+			continue;
+		}
+
 		int offset = strlen(ent->d_name) - 3;
 		if (offset < 0)
 			continue;
 		if (strcmp(&ent->d_name[offset], ".so"))
 			continue;
 
-		paths.push_back(std::string(libDir) + "/" + ent->d_name);
+		files.push_back(std::string(libDir) + "/" + ent->d_name);
 	}
 	closedir(dir);
 
+	return 0;
+}
+
+/**
+ * \brief Load IPA modules from a directory
+ * \param[in] libDir The directory to search for IPA modules
+ * \param[in] maxDepth The maximum depth of sub-directories to parse
+ *
+ * This method tries to create an IPAModule instance for every shared object
+ * found in \a libDir, and skips invalid IPA modules.
+ *
+ * \return Number of modules loaded by this call, or a negative error code
+ * otherwise
+ */
+int IPAManager::addDir(const char *libDir, unsigned int maxDepth)
+{
+	std::vector<std::string> files;
+
+	int ret = parseDir(libDir, files, maxDepth);
+	if (ret < 0)
+		return ret;
+
 	/* Ensure a stable ordering of modules. */
-	std::sort(paths.begin(), paths.end());
+	std::sort(files.begin(), files.end());
 
 	unsigned int count = 0;
-	for (const std::string &path : paths) {
-		IPAModule *ipaModule = new IPAModule(path);
+	for (const std::string &file : files) {
+		IPAModule *ipaModule = new IPAModule(file);
 		if (!ipaModule->isValid()) {
 			delete ipaModule;
 			continue;
 		}
 
-		LOG(IPAManager, Debug) << "Loaded IPA module '" << path << "'";
+		LOG(IPAManager, Debug) << "Loaded IPA module '" << file << "'";
 
 		modules_.push_back(ipaModule);
 		count++;
@@ -193,6 +231,7 @@ int IPAManager::addDir(const char *libDir)
 /**
  * \brief Load IPA modules from a search path
  * \param[in] path The colon-separated list of directories to load IPA modules from
+ * \param[in] maxDepth The maximum number of sub-directories to parse
  *
  * This method tries to create an IPAModule instance for every shared object
  * found in the directories listed in \a path.
@@ -200,7 +239,7 @@ int IPAManager::addDir(const char *libDir)
  * \return Number of modules loaded by this call, or a negative error code
  * otherwise
  */
-int IPAManager::addPath(const char *path)
+int IPAManager::addPath(const char *path, unsigned int maxDepth)
 {
 	int ipaCount = 0;
 
@@ -208,7 +247,7 @@ int IPAManager::addPath(const char *path)
 		if (dir.empty())
 			continue;
 
-		int ret = addDir(dir.c_str());
+		int ret = addDir(dir.c_str(), maxDepth);
 		if (ret > 0)
 			ipaCount += ret;
 	}
-- 
2.20.1