LTCD_070816.ISO

Windows/LTZ/COMPRESS.CPP

@@ -0,0 +1,196 @@
+#include "stdafx.h"
+#include "LTZ.h"
+
+int bit_test(int bit_num, BYTE *bit_field)
+{
+  __asm {
+    xor eax,eax
+    mov esi,bit_field
+    mov ebx,bit_num
+    bt [esi],ebx
+    adc eax,0
+  }
+}
+
+int bit_test_and_set(int bit_num, BYTE *bit_field)
+{
+  __asm {
+    xor eax,eax
+    mov esi,bit_field
+    mov ebx,bit_num
+    bts [esi],ebx
+    adc eax,0
+  }
+}
+
+DWORD ExtractWordBitField(BYTE *src,DWORD pos,DWORD bits)
+{
+  DWORD i,result=0;
+  for (i=0;i<bits;i++)
+    if (bit_test(pos+i,src))
+      bit_test_and_set(i,(BYTE *)&result);
+  return result;
+}
+
+void ArcGetTableEntry(ArcCs *c)
+{
+  DWORD i;
+  ArcTableEntry *temp,*temp1;
+
+  if (c->entry_used) {
+    i=c->free_index;
+
+    c->entry_used=FALSE;
+    c->cur_entry=c->next_entry;
+    c->cur_bits_in_use=c->next_bits_in_use;
+    if (c->next_bits_in_use<ARC_MAX_BITS) {
+      c->next_entry = &c->compress[i++];
+      if (i==c->free_limit) {
+	c->next_bits_in_use++;
+	c->free_limit=1<<c->next_bits_in_use;
+      }
+    } else {
+      do if (++i==c->free_limit) i=c->min_table_entry;
+      while (c->hash[i]);
+      temp=&c->compress[i];
+      c->next_entry=temp;
+      temp1=(ArcTableEntry *)&c->hash[temp->basecode];
+      while (temp1 && temp1->next!=temp)
+	temp1=temp1->next;
+      if (temp1)
+	temp1->next=temp->next;
+    }
+    c->free_index=i;
+  }
+}
+
+void ArcExpandBuf(ArcCs *c)
+{
+  BYTE *dst_ptr,*dst_limit;
+  DWORD basecode,lastcode,code;
+  ArcTableEntry *temp,*temp1;
+
+  dst_ptr=c->dst_buf+c->dst_pos;
+  dst_limit=c->dst_buf+c->dst_size;
+
+  while (dst_ptr<dst_limit &&
+	 c->stack_ptr!=c->stack_base)
+    *dst_ptr++ = * -- c->stack_ptr;
+
+  if (c->stack_ptr==c->stack_base && dst_ptr<dst_limit) {
+    if (c->saved_basecode==0xFFFFFFFF) {
+      lastcode=ExtractWordBitField(c->src_buf,c->src_pos,
+	 c->next_bits_in_use);
+      c->src_pos=c->src_pos+c->next_bits_in_use;
+      *dst_ptr++=lastcode;
+      ArcGetTableEntry(c);
+      c->last_ch=lastcode;
+    } else
+      lastcode=c->saved_basecode;
+    while (dst_ptr<dst_limit &&
+      c->src_pos+c->next_bits_in_use<=c->src_size) {
+      basecode=ExtractWordBitField(c->src_buf,c->src_pos,
+	 c->next_bits_in_use);
+      c->src_pos=c->src_pos+c->next_bits_in_use;
+      if (c->cur_entry==&c->compress[basecode]) {
+	*c->stack_ptr++=c->last_ch;
+	code=lastcode;
+      } else
+	code=basecode;
+      while (code>=c->min_table_entry) {
+	*c->stack_ptr++=c->compress[code].ch;
+	code=c->compress[code].basecode;
+      }
+      *c->stack_ptr++=code;
+      c->last_ch=code;
+
+      c->entry_used=TRUE;
+      temp=c->cur_entry;
+      temp->basecode=lastcode;
+      temp->ch=c->last_ch;
+      temp1=(ArcTableEntry *)&c->hash[lastcode];
+      temp->next=temp1->next;
+      temp1->next=temp;
+
+      ArcGetTableEntry(c);
+      while (dst_ptr<dst_limit && c->stack_ptr!=c->stack_base)
+	*dst_ptr++ = * -- c->stack_ptr;
+      lastcode=basecode;
+    }
+    c->saved_basecode=lastcode;
+  }
+  c->dst_pos=dst_ptr-c->dst_buf;
+}
+
+ArcCs *NewArcCs(DWORD expand,DWORD text_only)
+{
+  ArcCs *c;
+  c=(ArcCs *)malloc(sizeof(ArcCs));
+  memset(c,0,sizeof(ArcCs));
+  if (expand) {
+    c->stack_base=(BYTE *)malloc(ARC_MAX_TABLE_ENTRY+1);
+    c->stack_ptr=c->stack_base;
+  }
+  if (text_only)
+    c->min_bits=7;
+  else
+    c->min_bits=8;
+  c->min_table_entry=1<<c->min_bits;
+  c->free_index=c->min_table_entry;
+  c->next_bits_in_use=c->min_bits+1;
+  c->free_limit=1<<c->next_bits_in_use;
+  c->saved_basecode=0xFFFFFFFF;
+  c->entry_used=TRUE;
+  ArcGetTableEntry(c);
+  c->entry_used=TRUE;
+  return c;
+}
+
+void DelArcCs(ArcCs *c)
+{
+  free(c->stack_base);
+  free(c);
+}
+
+int ArcDetermineCompressionType(BYTE *src,DWORD size)
+{
+  DWORD i,j=0;
+  for (i=0;i<size;i++)
+    j=j|src[i];
+  if (j & 0x80)
+    return CT_8_BIT;
+  else
+    return CT_7_BIT;
+}
+
+
+BYTE *ExpandBuf(ArcCompressStruct *r)
+{
+  ArcCs *c;
+  ArcCompressStruct *r2=r;
+  BYTE *result;
+  DWORD text_only;
+  result=(BYTE *)malloc(r2->expanded_size+1);
+  result[r2->expanded_size]=0; //terminate
+
+  text_only=(r2->compression_type==CT_7_BIT);
+  if (r2->compression_type==CT_NONE) {
+    memcpy(result,r2->body,r2->expanded_size);
+    goto expand_end;
+  }
+  c=NewArcCs(TRUE,text_only);
+  c->src_size=r2->compressed_size*8;
+  c->src_pos=(sizeof(ArcCompressStruct)-1)*8;
+  c->src_buf=(BYTE *)r2;
+  c->dst_size=r2->expanded_size;
+  c->dst_buf=result;
+  c->dst_pos=0;
+  ArcExpandBuf(c);
+  DelArcCs(c);
+
+expand_end:
+  if (r2!=r)
+    free(r2);
+  return result;
+}
+