Andreas Krennmair:

implemented partitioning algorithm as preparation for parallel reload.
akrennmair · Nov 15, 2008 · e457c9b · e457c9b
1 parent 2c71da7
commit e457c9b
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Showing 3 changed files with 51 additions and 0 deletions.
diff --git a/include/utils.h b/include/utils.h
@@ -54,6 +54,8 @@ class utils {
 		static bool is_valid_color(const std::string& color);
 		static bool is_valid_attribute(const std::string& attrib);
 
+		static std::vector<std::pair<unsigned int, unsigned int> > partition_indexes(unsigned int start, unsigned int end, unsigned int parts);
+
 	private:
 		static void append_escapes(std::string& str, char c);
 

diff --git a/src/utils.cpp b/src/utils.cpp
@@ -604,4 +604,18 @@ bool utils::is_valid_attribute(const std::string& attrib) {
 	return false;
 }
 
+std::vector<std::pair<unsigned int, unsigned int> > utils::partition_indexes(unsigned int start, unsigned int end, unsigned int parts) {
+	std::vector<std::pair<unsigned int, unsigned int> > partitions;
+	unsigned int count = end - start + 1;
+	unsigned int size = count / parts;
+
+	for (unsigned int i=0;i<parts-1;i++) {
+		partitions.push_back(std::pair<unsigned int, unsigned int>(start, start + size - 1));
+		start += size;
+	}
+
+	partitions.push_back(std::pair<unsigned int, unsigned int>(start, end));
+	return partitions;
+}
+
 }
diff --git a/test/test.cpp b/test/test.cpp
@@ -598,3 +598,38 @@ BOOST_AUTO_TEST_CASE(TestHtmlRenderer) {
 	BOOST_CHECK(lines.size() >= 1);
 	BOOST_CHECK_EQUAL(lines[0], "A[i]");
 }
+
+BOOST_AUTO_TEST_CASE(TestIndexPartitioning) {
+	std::vector<std::pair<unsigned int, unsigned int> > partitions = utils::partition_indexes(0, 9, 2);
+	BOOST_CHECK_EQUAL(partitions.size(), 2u);
+	BOOST_CHECK_EQUAL(partitions[0].first, 0u);
+	BOOST_CHECK_EQUAL(partitions[0].second, 4u);
+	BOOST_CHECK_EQUAL(partitions[1].first, 5u);
+	BOOST_CHECK_EQUAL(partitions[1].second, 9u);
+
+	partitions = utils::partition_indexes(0, 10, 3);
+	BOOST_CHECK_EQUAL(partitions.size(), 3u);
+	BOOST_CHECK_EQUAL(partitions[0].first, 0u);
+	BOOST_CHECK_EQUAL(partitions[0].second, 2u);
+	BOOST_CHECK_EQUAL(partitions[1].first, 3u);
+	BOOST_CHECK_EQUAL(partitions[1].second, 5u);
+	BOOST_CHECK_EQUAL(partitions[2].first, 6u);
+	BOOST_CHECK_EQUAL(partitions[2].second, 10u);
+
+	partitions = utils::partition_indexes(0, 11, 3);
+	BOOST_CHECK_EQUAL(partitions.size(), 3u);
+	BOOST_CHECK_EQUAL(partitions[0].first, 0u);
+	BOOST_CHECK_EQUAL(partitions[0].second, 3u);
+	BOOST_CHECK_EQUAL(partitions[1].first, 4u);
+	BOOST_CHECK_EQUAL(partitions[1].second, 7u);
+	BOOST_CHECK_EQUAL(partitions[2].first, 8u);
+	BOOST_CHECK_EQUAL(partitions[2].second, 11u);
+
+	partitions = utils::partition_indexes(0, 199, 200);
+	BOOST_CHECK_EQUAL(partitions.size(), 200u);
+
+	partitions = utils::partition_indexes(0, 103, 1);
+	BOOST_CHECK_EQUAL(partitions.size(), 1u);
+	BOOST_CHECK_EQUAL(partitions[0].first, 0u);
+	BOOST_CHECK_EQUAL(partitions[0].second, 103u);
+}