From 203008def90c457b03f668a765166b966a075b4e Mon Sep 17 00:00:00 2001
From: Moinak Ghosh <moinakg@gmail.com>
Date: Mon, 30 Jul 2012 23:30:13 +0530
Subject: [PATCH] Further improve LZMA compression parameters to utilize all
 the 14 levels. Tweak some Rabin parmeters for better reduction with zlib and
 Bzip2.

---
 lzma_compress.c          | 18 +++++++++++++++---
 rabin/rabin_polynomial.c |  9 +++++++--
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/lzma_compress.c b/lzma_compress.c
index 02f80b2..8d0b2e6 100644
--- a/lzma_compress.c
+++ b/lzma_compress.c
@@ -64,26 +64,38 @@ lzma_init(void **data, int *level, ssize_t chunksize)
 			 * compression.
 			 */
 			p->dictSize = LZMA_DEFAULT_DICT;
+
 		} else {
 			/*
 			 * Let LZMA determine best dict size.
 			 */
 			p->dictSize = 0;
 		}
-		/* Determine the fast bytes value. */
+
+		/* Determine the fast bytes value and also adjust dict size further. */
 		if (*level < 7) {
 			p->fb = 32;
 
 		} else if (*level < 10) {
 			p->fb = 64;
 
-		} else if (*level < 13) {
+		} else if (*level == 11) {
 			p->fb = 64;
 			p->mc = 128;
 
-		} else {
+		} else if (*level == 12) {
 			p->fb = 128;
 			p->mc = 256;
+
+		} else if (*level == 13) {
+			p->fb = 64;
+			p->mc = 128;
+			p->dictSize = (1 << 27);
+
+		} else if (*level == 14) {
+			p->fb = 128;
+			p->mc = 256;
+			p->dictSize = (1 << 28);
 		}
 		if (*level > 9) *level = 9;
 		p->level = *level;
diff --git a/rabin/rabin_polynomial.c b/rabin/rabin_polynomial.c
index 202df14..4dbe473 100755
--- a/rabin/rabin_polynomial.c
+++ b/rabin/rabin_polynomial.c
@@ -120,7 +120,8 @@ create_rabin_context(uint64_t chunksize, uint64_t real_chunksize, const char *al
 
 	if (((memcmp(algo, "lzma", 4) == 0 || memcmp(algo, "adapt", 5) == 0) &&
 	      chunksize <= LZMA_WINDOW_MAX) || delta_flag) {
-		if (memcmp(algo, "lzfx", 4) == 0 || memcmp(algo, "lz4", 3) == 0) {
+		if (memcmp(algo, "lzfx", 4) == 0 || memcmp(algo, "lz4", 3) == 0 ||
+		    memcmp(algo, "zlib", 4) == 0) {
 			ctx->rabin_poly_min_block_size = RAB_POLYNOMIAL_MIN_BLOCK_SIZE2;
 			ctx->rabin_avg_block_mask = RAB_POLYNOMIAL_AVG_BLOCK_MASK2;
 			ctx->rabin_poly_avg_block_size = RAB_POLYNOMIAL_AVG_BLOCK_SIZE2;
@@ -129,7 +130,11 @@ create_rabin_context(uint64_t chunksize, uint64_t real_chunksize, const char *al
 			ctx->rabin_poly_min_block_size = RAB_POLYNOMIAL_MIN_BLOCK_SIZE;
 			ctx->rabin_avg_block_mask = RAB_POLYNOMIAL_AVG_BLOCK_MASK;
 			ctx->rabin_poly_avg_block_size = RAB_POLYNOMIAL_AVG_BLOCK_SIZE;
-			ctx->rabin_break_patt = RAB_POLYNOMIAL_CONST;
+			if (memcmp(algo, "bzip2", 5) == 0) {
+				ctx->rabin_break_patt = 0;
+			} else {
+				ctx->rabin_break_patt = RAB_POLYNOMIAL_CONST;
+			}
 		}
 	} else {
 		ctx->rabin_poly_min_block_size = RAB_POLYNOMIAL_MIN_BLOCK_SIZE2;