towards better views i hope

3 files changed, 280 insertions, 0 deletions

diff --git a/pcilib/register.h b/pcilib/register.h
index e7cbae9..9126e9f 100644
--- a/pcilib/register.h
+++ b/pcilib/register.h
@@ -47,6 +47,8 @@ typedef struct {
     pcilib_register_bank_t bank;		/**< Reference to bank containing the register */
     pcilib_register_value_t min, max;		/**< Minimum & maximum allowed values */
     pcilib_xml_node_t *xml;			/**< Additional XML properties */
+    pcilib_view_formula_t *formulas;            /**< list of views of type formula linked to this register*/
+    pcilib_view_enum_t *enums;                  /**< list of views of type enum linked to this register*/
 } pcilib_register_context_t;
 
 
diff --git a/views.c b/views.c
new file mode 100644
index 0000000..db96f4a
--- /dev/null
+++ b/views.c
@@ -0,0 +1,263 @@
+/**
+ * new type to define an enum view
+ */
+pcilib_value_enum_s {
+  const char *name; /**<corresponding string to value*/
+  pcilib_register_value_t value, min, max; 
+};
+
+
+/**
+ * new type to define a formula view
+ */
+pcilib_view_formula_s {
+  const char *name; /**<name of the view*/
+  const char *read_formula; /**< formula to parse to read from a register*/
+  const char *write_formula; /**<formula to parse to write to a register*/
+	// **see it later**        const char *unit; (?)
+}
+
+
+/**
+ *
+ * replace a substring within a string by another
+ * @param[in] txt - the string to be modified
+ *@param[in] before - the substring in the string that will be replaced
+ *@param[in] after - the new value of before substring
+ *@return the modified txt string
+ */
+char *formula_replace (const char *txt, const char *before, const char *after)
+{
+	const char *pos; 
+	char *return_txt; 
+	size_t pos_return_txt; 
+	size_t len; 
+	size_t allocated_size; 
+	
+	/*get the first occurence of before. then we need one time to be out of the loop to correctly set the diverses varaibles (malloc instead of realloc notably)*/
+	pos = strstr (txt, before);
+	 
+	if (pos == NULL)
+	{
+		pcilib_warning("problem with a formula");
+	}
+ 
+	/* get the position of this occurence*/
+	len = (size_t)pos - (size_t)txt;
+	allocated_size = len + strlen (after) + 1;
+	return_txt = malloc (allocated_size);
+	pos_return_txt = 0;
+	
+	/* we copy there the in a newly allocated string the start of txt before the "before" occurence, and then we copy after instead*/
+	strncpy (return_txt + pos_return_txt, txt, len);
+	pos_return_txt += len;
+	txt = pos + strlen (before);
+	 
+	len = strlen (after);
+	strncpy (return_txt + pos_return_txt, after, len);
+	pos_return_txt += len;
+	
+	/* we then iterate with the same principle to all occurences of before*/
+	pos = strstr (txt, before);
+	while (pos != NULL)
+	{
+		len = (size_t)pos - (size_t)txt;
+		allocated_size += len + strlen (after);
+		return_txt = (char *)realloc (return_txt, allocated_size);
+		 
+		strncpy (return_txt + pos_return_txt, txt, len);
+		pos_return_txt += len;
+		 
+		txt = pos + strlen (before);
+		 
+		len = strlen (after);
+		strncpy (return_txt + pos_return_txt, after, len);
+		pos_return_txt += len;
+		pos = strstr (txt, before);
+	}
+	/* put the rest of txt string at the end*/
+	len = strlen (txt) + 1;
+	allocated_size += len;
+	return_txt = realloc (return_txt, allocated_size);
+	strncpy (return_txt + pos_return_txt, txt, len);
+	
+	return return_txt;
+}
+
+/*
+ * function used to get the substring of a string s, from the starting and ending indexes
+  * @param[in] s string containing the substring we want to extract.
+ * @param[in] start the start index of the substring.
+ * @param[in] end the ending index of the substring.
+ * @return the extracted substring.
+ */
+char *str_sub (const char *s, unsigned int start, unsigned int end)
+{
+   char *new_s = NULL;
+
+   if (s != NULL && start < end)
+   {
+      new_s = malloc (sizeof (*new_s) * (end - start + 2));
+      if (new_s != NULL)
+      {
+         int i;
+
+         for (i = start; i <= end; i++)
+         {
+            new_s[i-start] = s[i];
+         }
+         new_s[i-start] = '\0';
+      }
+      else
+      {
+         pcilib_error("insufficient memory for string manipulation\n");
+         return NULL;
+      }
+   }
+   return new_s;
+}
+
+static int
+pcilib_view_compute_plain_registers{
+  /* hsould i used regexp.h??? or compile everythin myself? */
+}
+
+
+
+
+
+/*
+ * this function calls the python script and the function "evaluate" in it to evaluate the given formula
+ *@param[in] the formula to be evaluated
+ *@return the integer value of the evaluated formula (maybe go to float instead)
+ */
+static int
+pcilib_view_eval_formula(char* formula){
+/* !!!! cf !!!!*/
+  // setenv("PYTHONPATH",".",1);
+   PyObject *pName, *pModule, *pDict, *pFunc, *pValue, *presult=NULL;
+   char* pythonfile;
+
+   /* path to the python file, we may need a way to set it, maybe with a variable like PCILIB_PYTHON_PATH*/
+   pythonfile="pythonscripts.py";
+   
+   /* initialization of python interpreter*/
+   Py_Initialize();
+
+   pName = PyUnicode_FromString(pythonfile);
+   pModule = PyImport_Import(pName); /* get the python file*/
+	if(!pModule) {
+		pcilib_error("no python file found for python evaluation of formulas\n");
+		PyErr_Print();
+		return -1;
+	}
+   pDict = PyModule_GetDict(pModule); /*useless but needed*/
+
+   pFunc = PyDict_GetItemString(pDict, (char*)"evaluate"); /*getting of the function "evaluate" in the script*/
+   /* if the function is ok, then call it*/
+   if (PyCallable_Check(pFunc))
+   {
+        /* execution of the function*/
+       pValue=Py_BuildValue("(z)",formula);
+       PyErr_Print();
+       presult=PyObject_CallObject(pFunc,pValue);
+       PyErr_Print();
+   } else 
+   {
+       PyErr_Print();
+   }
+   /* remove memory*/
+   Py_DECREF(pModule);
+   Py_DECREF(pName);
+   
+   /* close interpreter*/
+   Py_Finalize();
+   
+   return PyLong_AsLong(presult); /*this function is due to python 3.3, as PyLong_AsInt was there in python 2.7 and is no more there, resulting in using cast futhermore*/
+}
+
+
+static int
+pcilib_view_apply_read_formula(pcilib_t* ctx, char* formula, pcilib_register_value_t reg_value, pcilib_register_value_t* out_value)
+{
+  /* when applying a formula, we need to:
+     1) compute the values of all registers present in plain name in the formulas and replace their name with their value : for example, if we have the formula" ((1./4)*(@reg - 1200)) if @freq==0 else ((3./10)*(@reg - 1000)) " we need to get the value of the register "freq"
+     2) compute the "@reg" component, corresponding to the raw value of the register
+     3) pass the formula to python interpreter for evaluation
+     4) return the final evaluation
+     
+     remark: it might be worth to use python regular expression interpreter (the following return all words following @ in formula : 
+         >>> import re
+	 >>> m = re.search('(?<=@)\w+', formula)
+	 >>> m.group(0)
+  */
+  
+  char reg_value_string[66]; /* to register reg_value as a string, need to check the length*/
+  sprintf(reg_value_string,"%lu",reg_value);
+  
+  /*computation of plain registers in the formula*/
+  formula=pcilib_view_formula_compute_plain_registers(formula);
+  /* computation of @reg with register value*/
+  formula=pcilib_view_formula_replace(formula,"@reg",reg_value_string);
+  
+  /* evaluation of the formula*/
+  *out_value=(pcilib_register_value_t) pcilib_view_eval_formula(formula);
+
+}
+
+static int
+pcilib_view_apply_write_formula()
+{
+}
+
+int pcilib_read_view(pcilib_t *ctx, const char *bank, const char *regname, const char *view/*, const char *unit*/, size_t value_size, void *value)
+{
+  int i,j,err;
+  pcilib_register_value_t temp_value;
+  
+  /* we get the index of the register to find the corresponding register context*/
+  if((i=pcilib_find_register(ctx,bank,regname))==PCILIB_REGISTER_INVALID){
+    pcilib_error("can't get the index of the register %s", regname);
+    return PCILIB_ERROR_INVALID_REQUEST;
+  }
+  
+  /* we get the value of the register, as we will apply the view on it*/
+  if((err==pcilib_read_register_by_id(ctx,i,&temp_value))>0){
+    pcilib_error("can't read the register %s value before applying views",regname);
+  }
+    /*in the case we don't ask for a view's name, we know it will be for views of type enum. Especially, it's faster to search directly on the values of those views instead of a given name.
+      we iterate so through the views of type enum to verify if the value we have corresponds to an enum command*/
+  if(!(view)){
+    for(j=0; ctx->register_ctx[i].enums[j].value;j++){
+      if((temp_value >= ctx->register_ctx[i].enums[j].min) && (temp_value <= ctx->register_ctx[i].enums[j].max)){
+	value_size=strlen(ctx->register_ctx[i].enums[j].name)*sizeof(char);
+	value=malloc(sizeof(value_size));
+	if(!(value)){
+	  pcilib_error("can't allocate memory for the returning value of the view %s",view);
+	  return PCILIB_ERROR_MEMORY;
+	}
+	/* in the case the value of register is between min and max, then we return the correponding enum command*/
+	value=*(char*)ctx->register_ctx[i].enums[j].name;
+	return 0;
+      }
+    }
+    pcilib_warning("the value of the register asked do not correspond to any enum views");
+    return PCILIB_ERROR_NOTAVAILABLE;
+  }
+  
+  /** in the other case we ask for a view of type formula. Indeed, wa can't directly ask for a formula, so we have to provide a name for those views*/
+  j=0;
+  while((ctx->register_ctx[i].formulas[j].name)){
+    if(!(strcasecmp(ctx->register_ctx[i].formulas[j].name))){
+      /* when we have found the correct view of type formula, we apply the formula, that get the good value for return*/
+      pcilib_view_apply_read_formula(ctx->register_ctx[i].formulas[j].read_formula,temp_value, value,....);
+      return 0;
+    }
+    j++;
+   }
+
+  pcilib_warning("the view asked and the register do not correspond");
+  return PCILIB_ERROR_NOTAVAILABLE;
+}
+ 
+      
diff --git a/views.h b/views.h
new file mode 100644
index 0000000..988e376
--- /dev/null
+++ b/views.h
@@ -0,0 +1,15 @@
+typedef struct pcilib_view_enum_s pcilib_view_enum_t;
+
+typedef struct pcilib_view_formula_s pcilib_view_formula_t;
+
+
+/**
+ * function to read a register using a view
+ */
+int pcilib_read_view(pcilib_t *ctx, const char *bank, const char *regname, const char *view/*, const char *unit*/, size_t value_size, void *value);
+
+/**
+ * function to write to a register using a view
+ */
+int pcilib_write_view(pcilib_t *ctx, const char *bank, const char *regname, const char *view/*, const char *unit*/, size_t value_size, void *value);
+