Fix: Respect -t temporary directory option in sorting operations (#368)

Enhance fqsort function to accept a temporary directory parameter for file handling. Update calls to fqsort in main.cpp, sort.cpp, sort.hpp, and unit.cpp to utilize the new parameter, ensuring temporary files are created in the specified directory.

main.cpp

@@ -2018,7 +2018,7 @@ std::pair<int, metadata> read_input(std::vector<source> &sources, char *fname, i
 			vertex_readers.push_back(readers[i].vertexfile);
 			rewind(readers[i].vertexfile);
 		}
-		fqsort(vertex_readers, sizeof(vertex), vertexcmp, vertex_out, memsize / 20);
+		fqsort(vertex_readers, sizeof(vertex), vertexcmp, vertex_out, memsize / 20, tmpdir);
 
 		for (size_t i = 0; i < CPUS; i++) {
 			if (fclose(readers[i].vertexfile) != 0) {
@@ -2087,7 +2087,7 @@ std::pair<int, metadata> read_input(std::vector<source> &sources, char *fname, i
 			rewind(readers[i].nodefile);
 		}
 
-		fqsort(node_readers, sizeof(node), nodecmp, node_out, memsize / 20);
+		fqsort(node_readers, sizeof(node), nodecmp, node_out, memsize / 20, tmpdir);
 
 		for (size_t i = 0; i < CPUS; i++) {
 			if (fclose(readers[i].nodefile) != 0) {

sort.cpp

@@ -6,7 +6,7 @@
 
 #define MAX_MEMORY (1024 * 1024 * 1024)	 // 1 GB
 
-void fqsort(std::vector<FILE *> &inputs, size_t width, int (*cmp)(const void *, const void *), FILE *out, size_t mem) {
+void fqsort(std::vector<FILE *> &inputs, size_t width, int (*cmp)(const void *, const void *), FILE *out, size_t mem, const char *tmpdir) {
 	std::string pivot;
 	FILE *fp1, *fp2;
 
@@ -67,8 +67,8 @@ void fqsort(std::vector<FILE *> &inputs, size_t width, int (*cmp)(const void *,
 		size_t pivot_off = width * (buf.size() / width / 2);
 		pivot = std::string(buf, pivot_off, width);
 
-		std::string t1 = "/tmp/sort1.XXXXXX";
-		std::string t2 = "/tmp/sort2.XXXXXX";
+		std::string t1 = std::string(tmpdir) + "/sort1.XXXXXX";
+		std::string t2 = std::string(tmpdir) + "/sort2.XXXXXX";
 
 		int fd1 = mkstemp((char *) t1.c_str());
 		unlink(t1.c_str());
@@ -117,11 +117,11 @@ void fqsort(std::vector<FILE *> &inputs, size_t width, int (*cmp)(const void *,
 
 	std::vector<FILE *> v1;
 	v1.emplace_back(fp1);
-	fqsort(v1, width, cmp, out, mem);
+	fqsort(v1, width, cmp, out, mem, tmpdir);
 	fclose(fp1);
 
 	std::vector<FILE *> v2;
 	v2.emplace_back(fp2);
-	fqsort(v2, width, cmp, out, mem);
+	fqsort(v2, width, cmp, out, mem, tmpdir);
 	fclose(fp2);
 }

sort.hpp

@@ -1,6 +1,6 @@
 #ifndef SORT_HPP
 #define SORT_HPP
 
-void fqsort(std::vector<FILE *> &inputs, size_t width, int (*cmp)(const void *, const void *), FILE *out, size_t mem);
+void fqsort(std::vector<FILE *> &inputs, size_t width, int (*cmp)(const void *, const void *), FILE *out, size_t mem, const char *tmpdir);
 
 #endif

unit.cpp

@@ -73,7 +73,7 @@ TEST_CASE("External quicksort", "fqsort") {
 	unlink(tmpname.c_str());
 	FILE *f = fdopen(fd, "w+b");
 
-	fqsort(inputs, sizeof(int), intcmp, f, 256);
+	fqsort(inputs, sizeof(int), intcmp, f, 256, "/tmp");
 	rewind(f);
 
 	int prev = INT_MIN;