1 files changed, 64 insertions, 0 deletions
diff --git a/src/liblzma/lzma/lzma_presets.c b/src/liblzma/lzma/lzma_presets.c
new file mode 100644
index 00000000..d49d2427
--- /dev/null
+++ b/src/liblzma/lzma/lzma_presets.c
@@ -0,0 +1,64 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       lzma_presets.c
+/// \brief      Encoder presets
+/// \note       xz needs this even when only decoding is enabled.
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "common.h"
+
+
+extern LZMA_API(lzma_bool)
+lzma_lzma_preset(lzma_options_lzma *options, uint32_t preset)
+{
+	const uint32_t level = preset & LZMA_PRESET_LEVEL_MASK;
+	const uint32_t flags = preset & ~LZMA_PRESET_LEVEL_MASK;
+	const uint32_t supported_flags = LZMA_PRESET_EXTREME;
+
+	if (level > 9 || (flags & ~supported_flags))
+		return true;
+
+	options->preset_dict = NULL;
+	options->preset_dict_size = 0;
+
+	options->lc = LZMA_LC_DEFAULT;
+	options->lp = LZMA_LP_DEFAULT;
+	options->pb = LZMA_PB_DEFAULT;
+
+	static const uint8_t dict_pow2[]
+			= { 18, 20, 21, 22, 22, 23, 23, 24, 25, 26 };
+	options->dict_size = UINT32_C(1) << dict_pow2[level];
+
+	if (level <= 3) {
+		options->mode = LZMA_MODE_FAST;
+		options->mf = level == 0 ? LZMA_MF_HC3 : LZMA_MF_HC4;
+		options->nice_len = level <= 1 ? 128 : 273;
+		static const uint8_t depths[] = { 4, 8, 24, 48 };
+		options->depth = depths[level];
+	} else {
+		options->mode = LZMA_MODE_NORMAL;
+		options->mf = LZMA_MF_BT4;
+		options->nice_len = level == 4 ? 16 : level == 5 ? 32 : 64;
+		options->depth = 0;
+	}
+
+	if (flags & LZMA_PRESET_EXTREME) {
+		options->mode = LZMA_MODE_NORMAL;
+		options->mf = LZMA_MF_BT4;
+		if (level == 3 || level == 5) {
+			options->nice_len = 192;
+			options->depth = 0;
+		} else {
+			options->nice_len = 273;
+			options->depth = 512;
+		}
+	}
+
+	return false;
+}