1 files changed, 112 insertions, 0 deletions
diff --git a/src/xz/hardware.c b/src/xz/hardware.c
new file mode 100644
index 000000000000..74742fcec870
--- /dev/null
+++ b/src/xz/hardware.c
@@ -0,0 +1,112 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       hardware.c
+/// \brief      Detection of available hardware resources
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "private.h"
+#include "tuklib_cpucores.h"
+
+
+/// Maximum number of free *coder* threads. This can be set with
+/// the --threads=NUM command line option.
+static uint32_t threadlimit;
+
+/// Memory usage limit
+static uint64_t memlimit;
+
+/// Total amount of physical RAM
+static uint64_t total_ram;
+
+
+extern void
+hardware_threadlimit_set(uint32_t new_threadlimit)
+{
+	if (new_threadlimit == 0) {
+		// The default is the number of available CPU cores.
+		threadlimit = tuklib_cpucores();
+		if (threadlimit == 0)
+			threadlimit = 1;
+	} else {
+		threadlimit = new_threadlimit;
+	}
+
+	return;
+}
+
+
+extern uint32_t
+hardware_threadlimit_get(void)
+{
+	return threadlimit;
+}
+
+
+extern void
+hardware_memlimit_set(uint64_t new_memlimit)
+{
+	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;
+			}
+		}
+	}
+
+	return;
+}
+
+
+extern void
+hardware_memlimit_set_percentage(uint32_t percentage)
+{
+	assert(percentage > 0);
+	assert(percentage <= 100);
+
+	memlimit = percentage * total_ram / 100;
+	return;
+}
+
+
+extern uint64_t
+hardware_memlimit_get(void)
+{
+	return memlimit;
+}
+
+
+extern void
+hardware_init(void)
+{
+	// Get the amount of RAM. If we cannot determine it,
+	// use the assumption defined by the configure script.
+	total_ram = lzma_physmem();
+	if (total_ram == 0)
+		total_ram = (uint64_t)(ASSUME_RAM) * 1024 * 1024;
+
+	// Set the defaults.
+	hardware_memlimit_set(0);
+	hardware_threadlimit_set(0);
+	return;
+}