From a571b8c92b0ec149f7691e786671ac5939cbf3c5 Mon Sep 17 00:00:00 2001
From: dianshi <dianshi@main.lv>
Date: Sun, 10 May 2020 12:53:03 +0100
Subject: working version

---
 rabincarp.c | 190 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 190 insertions(+)

(limited to 'rabincarp.c')

diff --git a/rabincarp.c b/rabincarp.c
index e69de29..a58ab15 100644
--- a/rabincarp.c
+++ b/rabincarp.c
@@ -0,0 +1,190 @@
+#include "rabincarp.h"
+
+
+int rlsi_hash_reset(rol_hash_isearch *rlh)
+{
+  rlh->pow = 1;
+  rlh->pattern_len = 0;
+  rlh->pattern_hash = 0;
+  rlh->text_hash = 0;
+  rlh->text_len = 0;
+  rlh->text = NULL;
+  rlh->pattern = NULL;
+  rlh->iter_pos = 0;
+  rlh->count = 0;
+  rlh->pre_text = NULL;
+  rlh->chunk_done = 0;
+  return 0;
+}
+
+int rlsi_hash_init(rol_hash_isearch *rlh, int b, int m)
+{
+  rlh->b = b;
+  rlh->m = m;
+  rlsi_hash_reset(rlh);
+  return 0;
+}
+
+int rlsi_hash_precalc(rol_hash_isearch *rlh, char *pattern, int plen, char *text, int tlen)
+{
+  int i;
+
+  if (tlen<plen)
+  {
+    return -1;
+  }
+
+  rlh->text_len    = tlen;
+  rlh->text        = text;
+  rlh->pattern     = pattern;
+  rlh->pattern_len = plen;
+
+  rlh->pow = 1;
+  for (i=0; i<plen-1; i++)
+  {
+    rlh->pow = (rlh->pow * rlh->b) % rlh->m;
+  }
+
+  rlh->text_hash = 0;
+  rlh->pattern_hash = 0;
+  for (i=0;i<plen;i++)
+  {
+    rlh->pattern_hash = (rlh->pattern_hash * rlh->b + pattern[i]) % rlh->m;
+    rlh->text_hash   =  (rlh->text_hash   * rlh->b + text[i])    % rlh->m;
+  }
+
+  //printf("pow %d\n",rlh->pow);
+  //printf("pattern %d\n",rlh->pattern_hash);
+  //printf("text %d\n",rlh->text_hash);
+
+  //set buffer size for presaved text
+  rlh->pre_text = malloc(plen);//dont check err =P, mem leak here
+  rlh->count = 0;
+
+  return 0;
+}
+
+//run after prepararion step
+int rlsi_hash_search(rol_hash_isearch *rlh, char *pattern, int plen, char *text, int tlen)
+{
+  int j=0;
+
+  int found=0;
+
+  if ((rlh->text == NULL) && (rlh->pattern == NULL))
+  {
+    rlsi_hash_precalc(rlh, pattern, plen, text, tlen);
+  }
+
+  if (rlh->chunk_done == 1)
+  {
+    rlh->chunk_done = 0;
+    rlh->text_len = tlen;
+  }
+
+  //printf("while %d",rlh->text_len-rlh->pattern_len);
+  //while (rlh->iter_pos<=(rlh->text_len-rlh->pattern_len))
+  while (rlh->iter_pos<=(rlh->text_len-rlh->pattern_len))
+  {
+
+    //hashes are matching
+    if (rlh->text_hash == rlh->pattern_hash)
+    {
+      //printf("2\n"); 
+      //check if string match
+      for (j=0;j<rlh->pattern_len;j++)
+      {
+        //???
+        char i_c=0;
+        int k=rlh->iter_pos+j;
+        if (k<0)
+        {
+          i_c = rlh->pre_text[rlh->pattern_len+k];
+        } else
+        {
+          //i_c = rlh->text[rlh->iter_pos+j];
+          i_c = text[rlh->iter_pos+j];
+        }
+        if (i_c != rlh->pattern[j])
+          break;
+      }
+
+      if (j == rlh->pattern_len)
+        {
+          //???
+          //printf("Found pattern at %d\n",rlh->iter_pos+1);
+          //printf("Found pattern at %d\n",rlh->count);
+          found = 1;
+        }
+      
+    }
+
+    //???
+    if (rlh->iter_pos < rlh->text_len - rlh->pattern_len)
+     {
+      //printf("1\n"); 
+      //???
+      char i_c;
+      if (rlh->iter_pos < 0)
+      {
+        i_c = rlh->pre_text[rlh->pattern_len+rlh->iter_pos];
+      } else
+      {
+        //i_c = rlh->text[rlh->iter_pos];
+        i_c = text[rlh->iter_pos];
+      }
+      //printf("CHAR: %c\n",i_c);
+      //rlh->text_hash = ( rlh->b *( rlh->text_hash - i_c*rlh->pow) + rlh->text[rlh->iter_pos+rlh->pattern_len] ) % rlh->m;
+      rlh->text_hash = ( rlh->b *( rlh->text_hash - i_c*rlh->pow) + text[rlh->iter_pos+rlh->pattern_len] ) % rlh->m;
+      //printf("text %d\n",rlh->text_hash);
+      if (rlh->text_hash < 0)
+      {
+        rlh->text_hash = rlh->text_hash + rlh->m;
+      }
+     }
+    
+    //iter over current buffer
+    rlh->iter_pos += 1;
+    //total data that have been iterated
+    rlh->count += 1;
+
+    if (found == 1)
+    {
+      //rlh->count -= 1;
+      return 1;
+    }
+    //iter over current buffer
+    //rlh->iter_pos += 1;
+    //total data that have been iterated
+    //rlh->count += 1;
+    //printf("rlh->iter_pos %d\n",rlh->iter_pos);
+    //printf("rlh->count %d\n",rlh->count);
+  }
+  //printf("tlen %d\n",tlen);
+  //exit from while loop because end of the buffer, iter is +1 element larger
+  //copy pattern to intermidiate buffer
+  //if ((rlh->iter_pos)==(rlh->text_len - rlh->pattern_len+1))
+  {
+    //copy last bit of buffer to further processing
+    //memcpy(rlh->pre_text, &rlh->text[rlh->iter_pos], rlh->pattern_len);
+    memcpy(rlh->pre_text, &text[rlh->iter_pos-1], rlh->pattern_len);
+    //printf("end of chunk\n");
+    //rlh->count -= 1;
+    //printf("count %d\n",rlh->count);
+
+    rlh->chunk_done = 1;
+    rlh->iter_pos = -rlh->pattern_len;
+  }
+
+//exit_loop:
+  //chunk finished search new need to be supplied pal
+  //printf("0\n");
+  rlh->count -= 1;
+  return 0;
+}
+
+int rlsi_hash_get(rol_hash_isearch *rlh)
+{
+  //return rlh->iter_pos;
+  return rlh->count;
+}
\ No newline at end of file
-- 
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