1 files changed, 63 insertions, 33 deletions

diff --git a/src/xz/hardware.c b/src/xz/hardware.c
index 74742fce..c7d4f4f0 100644
--- a/src/xz/hardware.c
+++ b/src/xz/hardware.c
@@ -18,8 +18,11 @@
 /// the --threads=NUM command line option.
 static uint32_t threadlimit;
 
-/// Memory usage limit
-static uint64_t memlimit;
+/// Memory usage limit for compression
+static uint64_t memlimit_compress;
+
+/// Memory usage limit for decompression
+static uint64_t memlimit_decompress;
 
 /// Total amount of physical RAM
 static uint64_t total_ram;
@@ -49,50 +52,77 @@ hardware_threadlimit_get(void)
 
 
 extern void
-hardware_memlimit_set(uint64_t new_memlimit)
+hardware_memlimit_set(uint64_t new_memlimit,
+		bool set_compress, bool set_decompress, bool is_percentage)
 {
-	if (new_memlimit != 0) {
-		memlimit = new_memlimit;
-	} else {
-		// The default depends on the amount of RAM but so that
-		// on "low-memory" systems the relative limit is higher
-		// to make it more likely that files created with "xz -9"
-		// will still decompress without overriding the limit
-		// manually.
-		//
-		// If 40 % of RAM is 80 MiB or more, use 40 % of RAM as
-		// the limit.
-		memlimit = 40 * total_ram / 100;
-		if (memlimit < UINT64_C(80) * 1024 * 1024) {
-			// If 80 % of RAM is less than 80 MiB,
-			// use 80 % of RAM as the limit.
-			memlimit = 80 * total_ram / 100;
-			if (memlimit > UINT64_C(80) * 1024 * 1024) {
-				// Otherwise use 80 MiB as the limit.
-				memlimit = UINT64_C(80) * 1024 * 1024;
-			}
-		}
+	if (is_percentage) {
+		assert(new_memlimit > 0);
+		assert(new_memlimit <= 100);
+		new_memlimit = (uint32_t)new_memlimit * total_ram / 100;
 	}
 
+	if (set_compress)
+		memlimit_compress = new_memlimit;
+
+	if (set_decompress)
+		memlimit_decompress = new_memlimit;
+
 	return;
 }
 
 
-extern void
-hardware_memlimit_set_percentage(uint32_t percentage)
+extern uint64_t
+hardware_memlimit_get(enum operation_mode mode)
 {
-	assert(percentage > 0);
-	assert(percentage <= 100);
+	// Zero is a special value that indicates the default. Currently
+	// the default simply disables the limit. Once there is threading
+	// support, this might be a little more complex, because there will
+	// probably be a special case where a user asks for "optimal" number
+	// of threads instead of a specific number (this might even become
+	// the default mode). Each thread may use a significant amount of
+	// memory. When there are no memory usage limits set, we need some
+	// default soft limit for calculating the "optimal" number of
+	// threads.
+	const uint64_t memlimit = mode == MODE_COMPRESS
+			? memlimit_compress : memlimit_decompress;
+	return memlimit != 0 ? memlimit : UINT64_MAX;
+}
+
+
+/// Helper for hardware_memlimit_show() to print one human-readable info line.
+static void
+memlimit_show(const char *str, uint64_t value)
+{
+	// The memory usage limit is considered to be disabled if value
+	// is 0 or UINT64_MAX. This might get a bit more complex once there
+	// is threading support. See the comment in hardware_memlimit_get().
+	if (value == 0 || value == UINT64_MAX)
+		printf("%s %s\n", str, _("Disabled"));
+	else
+		printf("%s %s MiB (%s B)\n", str,
+				uint64_to_str(round_up_to_mib(value), 0),
+				uint64_to_str(value, 1));
 
-	memlimit = percentage * total_ram / 100;
 	return;
 }
 
 
-extern uint64_t
-hardware_memlimit_get(void)
+extern void
+hardware_memlimit_show(void)
 {
-	return memlimit;
+	if (opt_robot) {
+		printf("%" PRIu64 "\t%" PRIu64 "\t%" PRIu64 "\n", total_ram,
+				memlimit_compress, memlimit_decompress);
+	} else {
+		memlimit_show(_("Total amount of physical memory (RAM): "),
+				total_ram);
+		memlimit_show(_("Memory usage limit for compression:    "),
+				memlimit_compress);
+		memlimit_show(_("Memory usage limit for decompression:  "),
+				memlimit_decompress);
+	}
+
+	tuklib_exit(E_SUCCESS, E_ERROR, message_verbosity_get() != V_SILENT);
 }
 
 
@@ -106,7 +136,7 @@ hardware_init(void)
 		total_ram = (uint64_t)(ASSUME_RAM) * 1024 * 1024;
 
 	// Set the defaults.
-	hardware_memlimit_set(0);
+	hardware_memlimit_set(0, true, true, false);
 	hardware_threadlimit_set(0);
 	return;
 }