git init1.1.103

1 files changed, 295 insertions, 0 deletions

diff --git a/epglv/src/epglvbase.c b/epglv/src/epglvbase.c
new file mode 100644
index 0000000..845edcb
--- /dev/null
+++ b/epglv/src/epglvbase.c
@@ -0,0 +1,295 @@
+/*
+
+EPG2VDR Levenshtein Distance UDF for MySQL
+Supports UTF-8 i throught iconv.
+
+Copyright (C) 2013 Jörg Wendel
+
+*/
+
+#include "epglv.h"
+
+//***************************************************************************
+// Declarations
+//***************************************************************************
+
+struct workspace_t  // structure to allocate memory in init and use it in core functions
+{
+   char*      str1;          // internal buffer to store 1st string
+   char*      str2;          // internal buffer to store 2nd string
+   int*       row0;          // round buffer for levenshtein_core function
+   int*       row1;          // round buffer for levenshtein_core function
+   int*       row2;          // round buffer for levenshtein_core function
+   mbstate_t* mbstate;       // buffer for mbsnrtowcs
+   iconv_t    ic;            // buffer for iconv
+   char       iconv_init;    // flag indicating if iconv has been inited before
+};
+
+//***************************************************************************
+// Function Declarations
+//***************************************************************************
+
+int epglv_core(struct workspace_t *ws,
+               const char *str1, int len1,
+               const char *str2, int len2,
+               int w, int s, int a, int d, int limit);
+
+char* epglv_utf8toiso(const char *str_src, long long *len_src,
+                      struct workspace_t * ws, char *str_dst, int limit);
+
+//***************************************************************************
+// The Work
+//***************************************************************************
+//***************************************************************************
+// init - check parameters and allocate memory for MySql
+//***************************************************************************
+
+my_bool base_epglv_init(UDF_INIT* init, UDF_ARGS* args, char* message)
+{
+    struct workspace_t *ws;
+
+    // make sure both arguments are ok
+    
+    if (args->arg_count != 2 || args->arg_type[0] != STRING_RESULT || args->arg_type[1] != STRING_RESULT)
+    {
+       strncpy(message, "EPGLV() requires arguments (string, string)", 80);
+       return 1;
+    }
+
+    init->maybe_null = 0;      // EPGLV() will not be returning null
+
+    // attempt to allocate memory in which to calculate distance
+
+    ws = (struct workspace_t*)malloc(sizeof(struct workspace_t));
+    ws->mbstate = (mbstate_t*)malloc(sizeof(mbstate_t));
+    ws->str1 = (char*)malloc(sizeof(char)*(LENGTH_MAX+2));    // max allocated for UTF-8 complex string
+    ws->str2 = (char*)malloc(sizeof(char)*(LENGTH_MAX+2));
+    ws->row0 = (int*)malloc(sizeof(int)*(LENGTH_MAX+2));
+    ws->row1 = (int*)malloc(sizeof(int)*(LENGTH_MAX+2));
+    ws->row2 = (int*)malloc(sizeof(int)*(LENGTH_MAX+2));
+    ws->iconv_init = 0;
+
+    if (!ws || !ws->mbstate || !ws->str1 || !ws->str2 || !ws->row0 || !ws->row1 || !ws->row2) 
+    {
+        free(ws->row2); free(ws->row1); free(ws->row0);
+        free(ws->str2); free(ws->str1);
+        free(ws->mbstate); free(ws);
+        strncpy(message, "EPGLV() failed to allocate memory", 80);
+        return 1;
+    }
+
+    if (!setlocale(LC_CTYPE, "de_DE.UTF-8")) 
+    {
+        free(ws->row2); free(ws->row1); free(ws->row0);
+        free(ws->str2); free(ws->str1);
+        free(ws->mbstate); free(ws);
+        strncpy(message, "EPGLV() failed to change locale", 80);
+        return 1;
+    }
+
+    init->ptr = (char *) ws;
+    debug_print("%s", "init successful");
+
+    return 0;
+}
+
+//***************************************************************************
+// deallocate memory, clean and close
+//***************************************************************************
+
+void base_epglv_deinit(UDF_INIT* init)
+{
+   if (init->ptr) 
+   {
+      struct workspace_t* ws = (struct workspace_t*)init->ptr;
+
+      if (ws->iconv_init)
+         iconv_close(ws->ic);
+
+      free(ws->row2);
+      free(ws->row1);
+      free(ws->row0);
+      free(ws->str2);
+      free(ws->str1);
+      free(ws->mbstate);
+      free(ws);
+   }
+
+   debug_print("%s", "bye");
+}
+
+//***************************************************************************
+// check parameters and allocate memory for MySql
+//***************************************************************************
+
+long long base_epglv(UDF_INIT* init, UDF_ARGS* args, char* is_null, char* error, 
+                     long long* len1, long long* len2)
+{
+   const char* str1 = args->args[0];
+   const char* str2 = args->args[1];
+  
+   char* iso_str1 = 0;
+   char* iso_str2 = 0;
+   struct workspace_t* ws = (struct workspace_t*)init->ptr;  // get a pointer to memory previously allocated
+
+   *error = 0; 
+   *len1 = (!str1) ? 0 : args->lengths[0];
+   *len2 = (!str2) ? 0 : args->lengths[1];
+   long long max = *len1 > *len2 ? *len1 : *len2;
+
+   if (max >= LENGTH_MAX) 
+   {
+      print("size(%lld) was bigger than %d, aborting", max, LENGTH_MAX);
+      return -1;
+   }
+
+   if (!*len1 && !*len2)
+      return 0;
+
+   if (!*len1 || !*len2)
+      return max;
+
+   if ((iso_str1 = epglv_utf8toiso(str1, len1, ws, ws->str1, max)) == 0)
+      return -1;
+
+   if ((iso_str2 = epglv_utf8toiso(str2, len2, ws, ws->str2, max)) == 0) 
+      return -1;
+   
+   return epglv_core(
+      ws,
+      iso_str1, *len1,
+      iso_str2, *len2,
+      /* swap */         1,
+      /* substitution */ 1,
+      /* insertion */    1,
+      /* deletion */     1,
+      /* limit */        max);
+}
+
+//***************************************************************************
+// core function
+//***************************************************************************
+
+int epglv_core(struct workspace_t* ws,
+                const char* str1, int len1,
+                const char* str2, int len2,
+                int w, int s, int a, int d, int limit) 
+{
+    int* row0 = ws->row0;
+    int* row1 = ws->row1;
+    int* row2 = ws->row2;
+    int i, j;
+
+    for (j = 0; j <= len2; j++)
+        row1[j] = j * a;
+
+    for (i = 0; i < len1; i++) 
+    {
+       int* dummy;
+       
+       row2[0] = (i + 1) * d;
+
+       for (j = 0; j < len2; j++) 
+       {
+          // substitution
+
+          row2[j + 1] = row1[j] + s * (str1[i] != str2[j]);
+
+          // swap
+
+          if (i > 0 && j > 0 && 
+              str1[i - 1] == str2[j] &&
+              str1[i] == str2[j - 1] &&
+              row2[j + 1] > row0[j - 1] + w) 
+          {
+             row2[j + 1] = row0[j - 1] + w;
+          }
+
+          // deletion
+
+          if (row2[j + 1] > row1[j + 1] + d) 
+             row2[j + 1] = row1[j + 1] + d;
+          
+          // insertion
+
+          if (row2[j + 1] > row2[j] + a) 
+             row2[j + 1] = row2[j] + a;
+       }
+       
+       dummy = row0;
+       row0 = row1;
+       row1 = row2;
+       row2 = dummy;
+    }
+    
+    debug_print("returning(%d)", row1[len2]);
+
+    return row1[len2];
+}
+
+//**************************************************************************
+// translates an UTF8 string to ISO with some error return codes
+//**************************************************************************
+
+char* epglv_utf8toiso(const char* str_src, long long* len_src,
+                      struct workspace_t* ws, char* str_dst, int limit) 
+{
+   mbstate_t* mbstate = ws->mbstate;
+   size_t len_mbsnrtowcs, len_ret = LENGTH_MAX, len_min = LENGTH_MAX;
+   char* ret = str_dst;
+   char* in_s = (char*)str_src;
+   
+   memset((void*)mbstate, '\0', sizeof(mbstate_t));
+   
+   if ((len_mbsnrtowcs = mbsnrtowcs(0, &str_src, *len_src, 0, mbstate)) == -1) 
+   {
+      print("mbsnrtowcs failed, str_src(%s): '%m'", str_src);
+      strncpy(str_dst, str_src, len_min);
+      str_dst[len_min] = 0; str_dst[len_min + 1] = 0;
+      *len_src = len_min;
+      return str_dst;
+   }
+   
+   len_min = MIN(len_mbsnrtowcs, limit);
+   
+   if (len_mbsnrtowcs == *len_src)
+   {
+      strncpy(str_dst, str_src, len_min);
+      str_dst[len_min] = 0; str_dst[len_min + 1] = 0;
+      *len_src = len_min;
+      return str_dst;
+   }
+   
+   if (!ws->iconv_init)
+   {
+      if ((ws->ic = iconv_open("ISO8859-15", "UTF-8")) == (iconv_t)-1)
+      {
+         print("%s", "failed to initialize iconv '%m'");
+         return 0;
+      }
+      
+      ws->iconv_init = 1;
+   }
+   
+   if (iconv(ws->ic, &in_s, (size_t*)len_src, &ret, &len_ret) == -1) 
+   {
+      if (errno != E2BIG)
+      {
+         print("in_s '%s' at '%s'; len_src (%lld) len_ret (%zu) '%m'", str_src, in_s, *len_src, len_ret);
+         strncpy(str_dst, str_src, len_min);
+         str_dst[len_min] = 0; str_dst[len_min + 1] = 0;
+         *len_src = len_min;
+         return str_dst;
+      }
+
+      print("inside E2BIG len_mbsnrtowcs(%zu) len_src(%lld)", len_mbsnrtowcs, *len_src);
+      len_mbsnrtowcs = len_min;
+   }
+   
+   *len_src = len_min;           // adjust converted length
+   str_dst[len_min] = 0; str_dst[len_min + 1] = 0;
+   
+   iconv(ws->ic, 0, 0, 0, 0);
+   
+   return str_dst;
+}