Merge pull request #252 from ladislav-zezula/LZ_PkLibOptimizations

Incorporated PKLIB optimizations by pionere (https://github.com/pionere).

3 files changed, 25 insertions, 29 deletions

diff --git a/src/pklib/explode.c b/src/pklib/explode.c
index 0f551d8..35210fb 100644
--- a/src/pklib/explode.c
+++ b/src/pklib/explode.c
@@ -31,7 +31,7 @@ char CopyrightPkware[] = "PKWARE Data Compression Library for Win32\r\n"
 //-----------------------------------------------------------------------------
 // Tables
 
-unsigned char DistBits[0x40] =
+const unsigned char DistBits[0x40] =
 {
     0x02, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
     0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
@@ -39,7 +39,7 @@ unsigned char DistBits[0x40] =
     0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08
 };
 
-unsigned char DistCode[0x40] =
+const unsigned char DistCode[0x40] =
 {
     0x03, 0x0D, 0x05, 0x19, 0x09, 0x11, 0x01, 0x3E, 0x1E, 0x2E, 0x0E, 0x36, 0x16, 0x26, 0x06, 0x3A,
     0x1A, 0x2A, 0x0A, 0x32, 0x12, 0x22, 0x42, 0x02, 0x7C, 0x3C, 0x5C, 0x1C, 0x6C, 0x2C, 0x4C, 0x0C,
@@ -47,28 +47,28 @@ unsigned char DistCode[0x40] =
     0xF0, 0x70, 0xB0, 0x30, 0xD0, 0x50, 0x90, 0x10, 0xE0, 0x60, 0xA0, 0x20, 0xC0, 0x40, 0x80, 0x00
 };
 
-unsigned char ExLenBits[0x10] =
+const unsigned char ExLenBits[0x10] =
 {
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08
 };
 
-unsigned short LenBase[0x10] =
+const unsigned short LenBase[0x10] =
 {
     0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
     0x0008, 0x000A, 0x000E, 0x0016, 0x0026, 0x0046, 0x0086, 0x0106
 };
 
-unsigned char LenBits[0x10] =
+const unsigned char LenBits[0x10] =
 {
     0x03, 0x02, 0x03, 0x03, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x07, 0x07
 };
 
-unsigned char LenCode[0x10] =
+const unsigned char LenCode[0x10] =
 {
     0x05, 0x03, 0x01, 0x06, 0x0A, 0x02, 0x0C, 0x14, 0x04, 0x18, 0x08, 0x30, 0x10, 0x20, 0x40, 0x00
 };
 
-unsigned char ChBitsAsc[0x100] =
+const unsigned char ChBitsAsc[0x100] =
 {
     0x0B, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x08, 0x07, 0x0C, 0x0C, 0x07, 0x0C, 0x0C,
     0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0D, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C,
@@ -88,7 +88,7 @@ unsigned char ChBitsAsc[0x100] =
     0x0D, 0x0D, 0x0C, 0x0C, 0x0C, 0x0D, 0x0D, 0x0D, 0x0D, 0x0D, 0x0D, 0x0D, 0x0D, 0x0D, 0x0D, 0x0D
 };
 
-unsigned short ChCodeAsc[0x100] =
+const unsigned short ChCodeAsc[0x100] =
 {
     0x0490, 0x0FE0, 0x07E0, 0x0BE0, 0x03E0, 0x0DE0, 0x05E0, 0x09E0,
     0x01E0, 0x00B8, 0x0062, 0x0EE0, 0x06E0, 0x0022, 0x0AE0, 0x02E0,
@@ -128,10 +128,10 @@ unsigned short ChCodeAsc[0x100] =
 // Local functions
 
 static void GenDecodeTabs(
-    unsigned char * positions,          // [out] Table of positions
-    unsigned char * start_indexes,      // [in] Table of start indexes
-    unsigned char * length_bits,        // [in] Table of lengths. Each length is stored as number of bits
-    size_t elements)                    // [in] Number of elements in start_indexes and length_bits
+    unsigned char * positions,           // [out] Table of positions
+    const unsigned char * start_indexes, // [in] Table of start indexes
+    const unsigned char * length_bits,   // [in] Table of lengths. Each length is stored as number of bits
+    size_t elements)                     // [in] Number of elements in start_indexes and length_bits
 {
     unsigned int index;
     unsigned int length;
@@ -150,7 +150,7 @@ static void GenDecodeTabs(
 
 static void GenAscTabs(TDcmpStruct * pWork)
 {
-    unsigned short * pChCodeAsc = &ChCodeAsc[0xFF];
+    const unsigned short * pChCodeAsc = &ChCodeAsc[0xFF];
     unsigned int  acc, add;
     unsigned short count;
 
@@ -479,7 +479,6 @@ unsigned int PKEXPORT explode(
     TDcmpStruct * pWork = (TDcmpStruct *)work_buf;
 
     // Initialize work struct and load compressed data
-    // Note: The caller must zero the "work_buff" before passing it to explode
     pWork->read_buf   = read_buf;
     pWork->write_buf  = write_buf;
     pWork->param      = param;
@@ -510,11 +509,11 @@ unsigned int PKEXPORT explode(
     }
 
     memcpy(pWork->LenBits, LenBits, sizeof(pWork->LenBits));
-    GenDecodeTabs(pWork->LengthCodes, LenCode, pWork->LenBits, sizeof(pWork->LenBits));
+    GenDecodeTabs(pWork->LengthCodes, LenCode, LenBits, sizeof(LenBits));
     memcpy(pWork->ExLenBits, ExLenBits, sizeof(pWork->ExLenBits));
     memcpy(pWork->LenBase, LenBase, sizeof(pWork->LenBase));
     memcpy(pWork->DistBits, DistBits, sizeof(pWork->DistBits));
-    GenDecodeTabs(pWork->DistPosCodes, DistCode, pWork->DistBits, sizeof(pWork->DistBits));
+    GenDecodeTabs(pWork->DistPosCodes, DistCode, DistBits, sizeof(DistBits));
     if(Expand(pWork) != 0x306)
         return CMP_NO_ERROR;
 
diff --git a/src/pklib/implode.c b/src/pklib/implode.c
index 1484ee2..96baf98 100644
--- a/src/pklib/implode.c
+++ b/src/pklib/implode.c
@@ -599,13 +599,11 @@ unsigned int PKEXPORT implode(
     unsigned int *dsize)
 {
     TCmpStruct * pWork = (TCmpStruct *)work_buf;
-    unsigned int nChCode;
     unsigned int nCount;
     unsigned int i;
     int nCount2;
 
     // Fill the work buffer information
-    // Note: The caller must zero the "work_buff" before passing it to implode
     pWork->read_buf    = read_buf;
     pWork->write_buf   = write_buf;
     pWork->dsize_bytes = *dsize;
@@ -638,11 +636,10 @@ unsigned int PKEXPORT implode(
     switch(*type)
     {
         case CMP_BINARY: // We will compress data with binary compression type
-            for(nChCode = 0, nCount = 0; nCount < 0x100; nCount++)
+            for(nCount = 0; nCount < 0x100; nCount++)
             {
                 pWork->nChBits[nCount]  = 9;
-                pWork->nChCodes[nCount] = (unsigned short)nChCode;
-                nChCode = (nChCode & 0x0000FFFF) + 2;
+                pWork->nChCodes[nCount] = nCount * 2;
             }
             break;
 
diff --git a/src/pklib/pklib.h b/src/pklib/pklib.h
index d9b2a70..c1e328d 100644
--- a/src/pklib/pklib.h
+++ b/src/pklib/pklib.h
@@ -116,14 +116,14 @@ typedef struct
 //-----------------------------------------------------------------------------
 // Tables (in explode.c)
 
-extern unsigned char DistBits[0x40];
-extern unsigned char DistCode[0x40];
-extern unsigned char ExLenBits[0x10];
-extern unsigned short LenBase[0x10];
-extern unsigned char LenBits[0x10];
-extern unsigned char LenCode[0x10];
-extern unsigned char ChBitsAsc[0x100];
-extern unsigned short ChCodeAsc[0x100];
+extern const unsigned char DistBits[0x40];
+extern const unsigned char DistCode[0x40];
+extern const unsigned char ExLenBits[0x10];
+extern const unsigned short LenBase[0x10];
+extern const unsigned char LenBits[0x10];
+extern const unsigned char LenCode[0x10];
+extern const unsigned char ChBitsAsc[0x100];
+extern const unsigned short ChCodeAsc[0x100];
 
 //-----------------------------------------------------------------------------
 // Public functions