[io] adjust array length checks in text-based buffers

Text-based buffers do not have 1GB limitation for object store.
But all kind of loops over array indicies made with Int_t so
elements count cann't be larger than max int value.

Adjust error message

Author: linev

io/io/src/TBufferJSON.cxx

@@ -3346,11 +3346,9 @@ void TBufferJSON::JsonWriteFastArray(const T *arr, Long64_t arrsize, const char
       fValue.Append("[]");
       return;
    }
-   constexpr Int_t dataWidth = 1; // at least 1
-   const Int_t maxElements = (std::numeric_limits<Int_t>::max() - Length())/dataWidth;
-   if (arrsize > maxElements)
-   {
-      Fatal("JsonWriteFastArray", "Not enough space left in the buffer (1GB limit). %lld elements is greater than the max left of %d", arrsize, maxElements);
+   const Int_t maxElements = std::numeric_limits<Int_t>::max();
+   if (arrsize > maxElements) {
+      Fatal("JsonWriteFastArray", "Array larger than 2^31 elements cannot be stored in JSON");
       return; // In case the user re-routes the error handler to not die when Fatal is called
    }
 

io/sql/src/TBufferSQL2.cxx

@@ -1376,15 +1376,12 @@ Int_t TBufferSQL2::SqlReadArraySize()
 template <typename T>
 R__ALWAYS_INLINE void TBufferSQL2::SqlWriteArray(T *arr, Long64_t arrsize, Bool_t withsize)
 {
-   constexpr Int_t dataWidth = 1; // at least 1
-   const Int_t maxElements = (std::numeric_limits<Int_t>::max() - Length())/dataWidth;
-   if (arrsize < 0 || arrsize > maxElements)
-   {
-      Fatal("SqlWriteArray", "Not enough space left in the buffer (1GB limit). %lld elements is greater than the max left of %d", arrsize, maxElements);
-      return; // In case the user re-routes the error handler to not die when Fatal is called
-   }
    if (!withsize && (arrsize <= 0))
       return;
+   if (arrsize > std::numeric_limits<Int_t>::max()) {
+      Fatal("SqlWriteArray", "Array larger than 2^31 elements cannot be stored in SQL");
+      return; // In case the user re-routes the error handler to not die when Fatal is called
+   }
    PushStack()->SetArray(withsize ? arrsize : -1);
    Int_t indx = 0;
    if (fCompressLevel > 0) {

io/xml/src/TBufferXML.cxx

@@ -2160,16 +2160,13 @@ void TBufferXML::WriteArray(const Double_t *d, Int_t n)
 template <typename T>
 R__ALWAYS_INLINE void TBufferXML::XmlWriteFastArray(const T *arr, Long64_t n)
 {
-   constexpr Int_t dataWidth = 1; // at least 1
-   const Int_t maxElements = (std::numeric_limits<Int_t>::max() - Length())/dataWidth;
-   if (n < 0 || n > maxElements)
-   {
-      Fatal("XmlWriteFastArray", "Not enough space left in the buffer (1GB limit). %lld elements is greater than the max left of %d", n, maxElements);
-      return; // In case the user re-routes the error handler to not die when Fatal is called
-   }
    BeforeIOoperation();
    if (n <= 0)
       return;
+   if (n > std::numeric_limits<Int_t>::max()) {
+      Fatal("XmlWriteFastArray", "Array larger than 2^31 elements cannot be stored in XML");
+      return; // In case the user re-routes the error handler to not die when Fatal is called
+   }
    XMLNodePointer_t arrnode = CreateItemNode(xmlio::Array);
    PushStack(arrnode);
    XmlWriteArrayContent(arr, n);