lcameraDev: Add session mgr lib for libcamera device binding

commonLibs/lcameraDev/selectorParse.cpp

@@ -0,0 +1,127 @@
+#include <selectorParse.h>
+#include <stdexcept>
+#include <cctype>
+
+namespace lcamera_dev {
+
+namespace {
+
+bool startsWith(const std::string& text, const std::string& prefix)
+{
+	return text.size() >= prefix.size()
+		&& text.compare(0, prefix.size(), prefix) == 0;
+}
+
+SelectorCriterionKind parseCriterionKind(const std::string& prefixToken)
+{
+	if (prefixToken == "lcamera-id") {
+		return SelectorCriterionKind::LibcameraId;
+	}
+	if (prefixToken == "index") {
+		return SelectorCriterionKind::Index;
+	}
+	if (prefixToken == "model-substr") {
+		return SelectorCriterionKind::ModelSubstr;
+	}
+	if (prefixToken == "model") {
+		return SelectorCriterionKind::Model;
+	}
+	if (prefixToken == "location") {
+		return SelectorCriterionKind::Location;
+	}
+
+	throw std::runtime_error(
+		"Unknown deviceSelector prefix: " + prefixToken);
+}
+
+SelectorCriterion parseCriterionClause(const std::string& clause)
+{
+	const std::string trimmedClause = trimWhitespace(clause);
+	if (trimmedClause.empty()) {
+		throw std::runtime_error("Empty deviceSelector clause");
+	}
+
+	const size_t colonPos = trimmedClause.find(':');
+	if (colonPos == std::string::npos)
+	{
+		return SelectorCriterion{
+			SelectorCriterionKind::LibcameraId,
+			trimmedClause
+		};
+	}
+
+	const std::string prefixToken = trimWhitespace(
+		trimmedClause.substr(0, colonPos));
+	const std::string value = trimWhitespace(
+		trimmedClause.substr(colonPos + 1));
+
+	if (value.empty())
+	{
+		throw std::runtime_error(
+			"deviceSelector clause has empty value for prefix "
+			+ prefixToken);
+	}
+
+	return SelectorCriterion{
+		parseCriterionKind(prefixToken),
+		value
+	};
+}
+
+} // namespace
+
+std::string trimWhitespace(const std::string& text)
+{
+	size_t start = 0;
+	while (start < text.size() && std::isspace(static_cast<unsigned char>(text[start]))) {
+		++start;
+	}
+
+	size_t end = text.size();
+	while (end > start
+		&& std::isspace(static_cast<unsigned char>(text[end - 1])))
+	{
+		--end;
+	}
+
+	return text.substr(start, end - start);
+}
+
+std::vector<SelectorCriterion> parseDeviceSelector(
+	const std::string& deviceSelector)
+{
+	const std::string trimmedSelector = trimWhitespace(deviceSelector);
+	if (trimmedSelector.empty()) {
+		throw std::runtime_error("deviceSelector is empty");
+	}
+
+	std::vector<SelectorCriterion> criteria;
+	std::string currentClause;
+	currentClause.reserve(trimmedSelector.size());
+
+	for (size_t i = 0; i < trimmedSelector.size(); ++i)
+	{
+		const char ch = trimmedSelector[i];
+		if (ch == '\\' && i + 1 < trimmedSelector.size()
+			&& trimmedSelector[i + 1] == ';')
+		{
+			currentClause.push_back(';');
+			++i;
+			continue;
+		}
+
+		if (ch == ';')
+		{
+			criteria.push_back(parseCriterionClause(currentClause));
+			currentClause.clear();
+			continue;
+		}
+
+		currentClause.push_back(ch);
+	}
+
+	criteria.push_back(parseCriterionClause(currentClause));
+	return criteria;
+}
+
+} // namespace lcamera_dev