Introduce truncation info

odbc-api/src/buffers/columnar.rs

@@ -10,7 +10,7 @@ use crate::{
     handles::{CDataMut, Statement, StatementRef},
     parameter::WithDataType,
     result_set_metadata::utf8_display_sizes,
-    Error, ResultSetMetadata, RowSetBuffer,
+    Error, ResultSetMetadata, RowSetBuffer, cursor::TruncationInfo,
 };
 
 use super::{Indicator, TextColumn};
@@ -104,10 +104,11 @@ where
         Ok(())
     }
 
-    fn find_truncation(&self) -> Option<Indicator> {
+    fn find_truncation(&self) -> Option<TruncationInfo> {
         self.columns
             .iter()
             .find_map(|col_buffer| col_buffer.1.has_truncated_values(*self.num_rows))
+            .map(|indicator| TruncationInfo { indicator })
     }
 }
 

odbc-api/src/cursor.rs

@@ -390,7 +390,15 @@ pub unsafe trait RowSetBuffer {
     unsafe fn bind_colmuns_to_cursor(&mut self, cursor: StatementRef<'_>) -> Result<(), Error>;
 
     /// Find an indicator larger than the maximum element size of the buffer.
-    fn find_truncation(&self) -> Option<Indicator>;
+    fn find_truncation(&self) -> Option<TruncationInfo>;
+}
+
+/// Returned by [`RowSetBuffer::find_truncation`]. Contains information about the truncation found.
+pub struct TruncationInfo {
+    /// Indicator of the complete untruncated value.
+    pub indicator: Indicator,
+    // /// Zero based buffer index of the column in which the truncation occurred.
+    // pub buffer_index: usize,
 }
 
 unsafe impl<T: RowSetBuffer> RowSetBuffer for &mut T {
@@ -410,7 +418,7 @@ unsafe impl<T: RowSetBuffer> RowSetBuffer for &mut T {
         (*self).bind_colmuns_to_cursor(cursor)
     }
 
-    fn find_truncation(&self) -> Option<Indicator> {
+    fn find_truncation(&self) -> Option<TruncationInfo> {
         (**self).find_truncation()
     }
 }
@@ -733,7 +741,7 @@ fn error_handling_for_fetch(
     // while we are limited in the amount we can check. The second check serves as an optimization
     // for the happy path.
     if error_for_truncation && result == SqlResult::SuccessWithInfo(()) {
-        if let Some(indicator) = buffer.find_truncation() {
+        if let Some(TruncationInfo { indicator }) = buffer.find_truncation() {
             return Err(Error::TooLargeValueForBuffer { indicator });
         }
     }

odbc-api/src/lib.rs

@@ -31,7 +31,8 @@ pub use self::{
     columnar_bulk_inserter::{BoundInputSlice, ColumnarBulkInserter},
     connection::{escape_attribute_value, Connection, ConnectionOptions},
     cursor::{
-        BlockCursor, BlockCursorPolling, Cursor, CursorImpl, CursorPolling, CursorRow, RowSetBuffer,
+        BlockCursor, BlockCursorPolling, Cursor, CursorImpl, CursorPolling, CursorRow,
+        RowSetBuffer, TruncationInfo,
     },
     driver_complete_option::DriverCompleteOption,
     environment::{DataSourceInfo, DriverInfo, Environment},

odbc-api/tests/common.rs

@@ -2,9 +2,9 @@ use std::iter::repeat;
 
 use lazy_static::lazy_static;
 use odbc_api::{
-    buffers::{self, Indicator},
+    buffers,
     handles::{CDataMut, Statement, StatementRef},
-    Connection, ConnectionOptions, Cursor, Environment, Error, RowSetBuffer,
+    Connection, ConnectionOptions, Cursor, Environment, Error, RowSetBuffer, TruncationInfo,
 };
 
 // Rust by default executes tests in parallel. Yet only one environment is allowed at a time.
@@ -209,7 +209,7 @@ where
         Ok(())
     }
 
-    fn find_truncation(&self) -> Option<Indicator> {
+    fn find_truncation(&self) -> Option<TruncationInfo> {
         unimplemented!()
     }
 }