Get rid of StampFixed base class. It makes code more comples, instead of making it more simple

Author: nataraj-hates-MS-for-stealing-github

blobstamper/stamp.h

@@ -1,6 +1,6 @@
 /******************************************************************************
  *
- * Copyright 2021 Nikolay Shaplov (Postgres Professional)
+ * Copyright 2021-2023 Nikolay Shaplov (Postgres Professional)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -107,15 +107,6 @@ StampBaseV<T>::ExtractBin(Blob &blob)
   return v;
 }
 
-class StampFixed : public virtual StampBase
-{
-  protected:
-     int  size;
-  public:
-    virtual int  minSize() override {return size;}
-    virtual int  maxSize() override {return size;}
-};
-
 class StampVariated : public virtual StampBase
 {
   protected:

blobstamper/stamp_arithm.h

@@ -23,10 +23,11 @@
 #include "helpers.h"
 #include "stamp.h"
 
-template<class T> class StampArithm: public StampFixed, public StampBaseStr, public StampBaseV<T>
+template<class T> class StampArithm: public StampBaseStr, public StampBaseV<T>
 {
   public:
-    StampArithm() { size = sizeof(T);};
+    virtual int  minSize() override {return sizeof(T);}
+    virtual int  maxSize() override {return sizeof(T);}
     virtual std::string ExtractStr(Blob &blob) override;
     virtual T ExtractValue(Blob &blob) override;
 };

blobstamper/stamp_dict.h

@@ -26,7 +26,7 @@
 #include "stamp_arithm.h"
 #include "dict.h"
 
-class StampDict: public StampFixed, public StampBaseStr
+class StampDict: public StampBaseStr
 {
   protected:
     StampArithm<unsigned char>  stamp8;

t/test-chars-stamps.h

@@ -1,6 +1,6 @@
 /******************************************************************************
  *
- * Copyright 2021 Nikolay Shaplov (Postgres Professional)
+ * Copyright 2021-2023 Nikolay Shaplov (Postgres Professional)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,39 +19,35 @@
 /* This stamps chops first two bytes and treat them as string */
 /* Never do this in real live, as blob is binary and may have \0 in the middle of it*/
 
-class StampTwoChars: public StampFixed, public StampBaseStr
+class StampTwoChars: public StampBaseStr
 {
   public:
-    StampTwoChars();
     std::string ExtractStr(Blob &blob) override;
-};
+    virtual int  minSize() override {return 2;} /* This stamp shifts two characters only */
+    virtual int  maxSize() override {return 2;} /* This stamp shifts two characters only */
 
-StampTwoChars::StampTwoChars() : StampFixed()
-{
-    size = 2;  /* This stamp shifts two characters only */
-}
+};
 
 std::string
 StampTwoChars::ExtractStr(Blob &blob)
 {
-    char * buf;
-    size_t buf_size;
+    /* Chopping suitable data chunk from blob */
+    std::vector<char> data = blob.ChopBlank(*this);
 
-    Blob blob2 = blob.ShiftBytes(size);
-    if (blob2.isEmpty())
-        return "";
+    size_t buf_size = data.size() + 1;
+    char * buf = (char *) malloc(buf_size);
+    memcpy(buf, &data[0], data.size());
+    buf[buf_size-1] = '\0';
 
     /* Save shited data as string */
     /* NEVER do this in prod, as in real live blob is binary and may have 0 in the middle of it */
-    blob2.DataDup(buf, buf_size);
-    buf = (char *) realloc((void *)buf, buf_size + 1);
-    buf[buf_size] = '\0';
     std::string res = buf;
     free(buf);
 
     return res;
 }
 
+/*****************************************************************************/
 class StampSeveralChars: public StampVariated, public StampBaseStr
 {
   public: