From c1ef7a177fae1f5435f191cbdebb0c59fb81d8ff Mon Sep 17 00:00:00 2001
From: Przemyslaw Skibinski <inikep@gmail.com>
Date: Tue, 6 Dec 2016 15:21:28 +0100
Subject: introduced LZ4HC_compress_hashChain

---
 lib/lz4hc.c | 30 +++++++++++++++++++++++++++---
 lib/lz4hc.h |  8 +++++---
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/lib/lz4hc.c b/lib/lz4hc.c
index 298550c..57587f3 100644
--- a/lib/lz4hc.c
+++ b/lib/lz4hc.c
@@ -305,8 +305,9 @@ FORCE_INLINE int LZ4HC_encodeSequence (
     return 0;
 }
 
+#include "lz4opt.h"
 
-static int LZ4HC_compress_generic (
+static int LZ4HC_compress_hashChain (
     LZ4HC_CCtx_internal* const ctx,
     const char* const source,
     char* const dest,
@@ -336,8 +337,6 @@ static int LZ4HC_compress_generic (
     const BYTE* ref0;
 
     /* init */
-    if (compressionLevel > LZ4HC_MAX_CLEVEL) compressionLevel = LZ4HC_MAX_CLEVEL;
-    if (compressionLevel < 1) compressionLevel = LZ4HC_DEFAULT_CLEVEL;
     maxNbAttempts = 1 << (compressionLevel-1);
     ctx->end += inputSize;
 
@@ -490,6 +489,31 @@ _Search3:
 }
 
 
+static int LZ4HC_compress_generic (
+    LZ4HC_CCtx_internal* const ctx,
+    const char* const source,
+    char* const dest,
+    int const inputSize,
+    int const maxOutputSize,
+    int compressionLevel,
+    limitedOutput_directive limit
+    )
+{
+    if (compressionLevel < 1) compressionLevel = LZ4HC_DEFAULT_CLEVEL;
+    if (compressionLevel > 16) {
+        switch (compressionLevel) {
+            case 17: ctx->searchNum = 64; return LZ4HC_compress_optimal(ctx, source, dest, inputSize, maxOutputSize, limit, 0, 64, 0);
+            case 18: ctx->searchNum = 256; return LZ4HC_compress_optimal(ctx, source, dest, inputSize, maxOutputSize, limit, 0, 256, 0);
+            case 19: ctx->searchNum = 64; return LZ4HC_compress_optimal(ctx, source, dest, inputSize, maxOutputSize, limit, 1, 64, 0);
+            case 20:
+            default: ctx->searchNum = 256; return LZ4HC_compress_optimal(ctx, source, dest, inputSize, maxOutputSize, limit, 1, 256, 0);
+        }
+    }
+
+    return LZ4HC_compress_hashChain(ctx, source, dest, inputSize, maxOutputSize, compressionLevel, limit);
+}
+
+
 int LZ4_sizeofStateHC(void) { return sizeof(LZ4_streamHC_t); }
 
 int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel)
diff --git a/lib/lz4hc.h b/lib/lz4hc.h
index d8ac3c0..40ca401 100644
--- a/lib/lz4hc.h
+++ b/lib/lz4hc.h
@@ -46,7 +46,7 @@ extern "C" {
 /* --- Useful constants --- */
 #define LZ4HC_MIN_CLEVEL        3
 #define LZ4HC_DEFAULT_CLEVEL    9
-#define LZ4HC_MAX_CLEVEL        16
+#define LZ4HC_MAX_CLEVEL        20
 
 
 /*-************************************
@@ -58,7 +58,7 @@ extern "C" {
  * Compression is guaranteed to succeed if `dstCapacity >= LZ4_compressBound(srcSize)` (see "lz4.h")
  * Max supported `srcSize` value is LZ4_MAX_INPUT_SIZE (see "lz4.h")
  * `compressionLevel` : Recommended values are between 4 and 9, although any value between 1 and LZ4HC_MAX_CLEVEL will work.
- *                      Values >LZ4HC_MAX_CLEVEL behave the same as 16.
+ *                      Values >LZ4HC_MAX_CLEVEL behave the same as LZ4HC_MAX_CLEVEL.
  * @return : the number of bytes written into 'dst'
  *           or 0 if compression fails.
  */
@@ -153,6 +153,7 @@ typedef struct
     uint32_t   dictLimit;        /* below that point, need extDict */
     uint32_t   lowLimit;         /* below that point, no more dict */
     uint32_t   nextToUpdate;     /* index from which to continue dictionary update */
+    uint32_t   searchNum;        /* only for optimal parser */
     uint32_t   compressionLevel;
 } LZ4HC_CCtx_internal;
 
@@ -169,12 +170,13 @@ typedef struct
     unsigned int   dictLimit;        /* below that point, need extDict */
     unsigned int   lowLimit;         /* below that point, no more dict */
     unsigned int   nextToUpdate;     /* index from which to continue dictionary update */
+    unsigned int   searchNum;        /* only for optimal parser */
     unsigned int   compressionLevel;
 } LZ4HC_CCtx_internal;
 
 #endif
 
-#define LZ4_STREAMHCSIZE        262192
+#define LZ4_STREAMHCSIZE        262200
 #define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t))
 union LZ4_streamHC_u {
     size_t table[LZ4_STREAMHCSIZE_SIZET];
-- 
cgit v0.12