Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/src/liblzma/api/lzma/hardware.h

+/**
+ * \file        lzma/hardware.h
+ * \brief       Hardware information
+ *
+ * Since liblzma can consume a lot of system resources, it also provides
+ * ways to limit the resource usage. Applications linking against liblzma
+ * need to do the actual decisions how much resources to let liblzma to use.
+ * To ease making these decisions, liblzma provides functions to find out
+ * the relevant capabilities of the underlaying hardware. Currently there
+ * is only a function to find out the amount of RAM, but in the future there
+ * will be also a function to detect how many concurrent threads the system
+ * can run.
+ *
+ * \note        On some operating systems, these function may temporarily
+ *              load a shared library or open file descriptor(s) to find out
+ *              the requested hardware information. Unless the application
+ *              assumes that specific file descriptors are not touched by
+ *              other threads, this should have no effect on thread safety.
+ *              Possible operations involving file descriptors will restart
+ *              the syscalls if they return EINTR.
+ */
+
+/*
+ * Author: Lasse Collin
+ *
+ * This file has been put into the public domain.
+ * You can do whatever you want with this file.
+ *
+ * See ../lzma.h for information about liblzma as a whole.
+ */
+
+#ifndef LZMA_H_INTERNAL
+#       error Never include this file directly. Use <lzma.h> instead.
+#endif
+
+
+/**
+ * \brief       Get the total amount of physical memory (RAM) in bytes
+ *
+ * This function may be useful when determining a reasonable memory
+ * usage limit for decompressing or how much memory it is OK to use
+ * for compressing. For example, the default limit used by the xz
+ * command line tool is 40 % of RAM.
+ *
+ * \return      On success, the total amount of physical memory in bytes
+ *              is returned. If the amount of RAM cannot be determined,
+ *              zero is returned. This can happen if an error occurs
+ *              or if there is no code in liblzma to detect the amount
+ *              of RAM on the specific operating system.
+ */
+extern LZMA_API(uint64_t) lzma_physmem(void) lzma_nothrow;