more initialization stuff out of main(), remove weird coincidentally successful one_g variable

util.c

@@ -133,6 +133,29 @@ void failure(const char *format, ...)
 	fatal_exit();
 }
 
+void setup_ram(rzip_control *control)
+{
+	/* Use less ram when using STDOUT to store the temporary output file. */
+	if (STDOUT && ((STDIN && DECOMPRESS) || !(DECOMPRESS || TEST_ONLY)))
+		control->maxram = control->ramsize * 2 / 9;
+	else
+		control->maxram = control->ramsize / 3;
+	if (BITS32) {
+		/* Decrease usable ram size on 32 bits due to kernel /
+		 * userspace split. Cannot allocate larger than a 1
+		 * gigabyte chunk due to 32 bit signed long being
+		 * used in alloc, and at most 3GB can be malloced, and
+		 * 2/3 of that makes for a total of 2GB to be split
+		 * into thirds.
+		 */
+		control->usable_ram = MAX(control->ramsize - 900000000ll, 900000000ll);
+		control->maxram = MIN(control->maxram, control->usable_ram);
+		control->maxram = MIN(control->maxram, one_g * 2 / 3);
+	} else
+		control->usable_ram = control->maxram;
+	round_to_page(&control->maxram);
+}
+
 void round_to_page(i64 *size)
 {
 	*size -= *size % PAGE_SIZE;