Fix C++ client reading FLOAT inference columns declared as DOUBLE (#17759)

* Fix C++ client reading FLOAT inference columns declared as DOUBLE

CALL INFERENCE returns FLOAT data in TsBlock while the result schema
declares DOUBLE. Coerce by actual column type in getDouble/getFloat to
avoid Unsupported operation: getDouble when iterating RowRecord.

* Move column type coercion test into sessionIT.cpp

Avoid a separate test source file; keep the same coverage in session_tests.

* Implement numeric widening getters on C++ Column classes

Align with Java TsFile: IntColumn/FloatColumn/LongColumn support cross-type
getters (e.g. FloatColumn::getDouble). IoTDBRpcDataSet delegates directly to
column getters like the Java client. Fixes CALL INFERENCE crash when schema
declares DOUBLE but TsBlock stores FLOAT (including RLE-encoded columns).

Author: hongzhi-gao

iotdb-client/client-cpp/src/main/Column.cpp

@@ -152,6 +152,18 @@ int32_t IntColumn::getInt(int32_t position) const {
   return values_[position + arrayOffset_];
 }
 
+int64_t IntColumn::getLong(int32_t position) const {
+  return values_[position + arrayOffset_];
+}
+
+float IntColumn::getFloat(int32_t position) const {
+  return values_[position + arrayOffset_];
+}
+
+double IntColumn::getDouble(int32_t position) const {
+  return values_[position + arrayOffset_];
+}
+
 std::vector<int32_t> IntColumn::getInts() const {
   return values_;
 }
@@ -204,6 +216,10 @@ float FloatColumn::getFloat(int32_t position) const {
   return values_[position + arrayOffset_];
 }
 
+double FloatColumn::getDouble(int32_t position) const {
+  return values_[position + arrayOffset_];
+}
+
 std::vector<float> FloatColumn::getFloats() const {
   return values_;
 }
@@ -256,6 +272,10 @@ int64_t LongColumn::getLong(int32_t position) const {
   return values_[position + arrayOffset_];
 }
 
+double LongColumn::getDouble(int32_t position) const {
+  return values_[position + arrayOffset_];
+}
+
 std::vector<int64_t> LongColumn::getLongs() const {
   return values_;
 }

iotdb-client/client-cpp/src/main/Column.h

@@ -196,6 +196,9 @@ class IntColumn : public Column {
   ColumnEncoding getEncoding() const override;
 
   int32_t getInt(int32_t position) const override;
+  int64_t getLong(int32_t position) const override;
+  float getFloat(int32_t position) const override;
+  double getDouble(int32_t position) const override;
   std::vector<int32_t> getInts() const override;
 
   bool mayHaveNull() const override;
@@ -220,6 +223,7 @@ class FloatColumn : public Column {
   ColumnEncoding getEncoding() const override;
 
   float getFloat(int32_t position) const override;
+  double getDouble(int32_t position) const override;
   std::vector<float> getFloats() const override;
 
   bool mayHaveNull() const override;
@@ -244,6 +248,7 @@ class LongColumn : public Column {
   ColumnEncoding getEncoding() const override;
 
   int64_t getLong(int32_t position) const override;
+  double getDouble(int32_t position) const override;
   std::vector<int64_t> getLongs() const override;
 
   bool mayHaveNull() const override;

iotdb-client/client-cpp/src/test/cpp/sessionIT.cpp

@@ -18,6 +18,7 @@
  */
 
 #include "catch.hpp"
+#include "Column.h"
 #include "Session.h"
 #include "SessionBuilder.h"
 #include "TsBlock.h"
@@ -878,4 +879,23 @@ TEST_CASE("TsBlock deserialize rejects truncated malicious payload", "[TsBlockDe
   std::string data(18, '\0');
   data[3] = '\x10';
   REQUIRE_THROWS_AS(TsBlock::deserialize(data), IoTDBException);
+}
+
+TEST_CASE("Numeric column widening getters align with Java TsFile", "[column]") {
+  std::vector<bool> valueIsNull(1, false);
+
+  std::vector<float> floatValues = {120.00000762939453f};
+  auto floatColumn = std::make_shared<FloatColumn>(0, 1, valueIsNull, floatValues);
+  auto rleColumn = std::make_shared<RunLengthEncodedColumn>(floatColumn, 20);
+  REQUIRE(floatColumn->getDouble(0) == Approx(120.0).margin(0.01));
+  REQUIRE(rleColumn->getDouble(0) == Approx(120.0).margin(0.01));
+
+  std::vector<int32_t> intValues = {42};
+  auto intColumn = std::make_shared<IntColumn>(0, 1, valueIsNull, intValues);
+  REQUIRE(intColumn->getLong(0) == 42);
+  REQUIRE(intColumn->getDouble(0) == Approx(42.0));
+
+  std::vector<int64_t> longValues = {1000};
+  auto longColumn = std::make_shared<LongColumn>(0, 1, valueIsNull, longValues);
+  REQUIRE(longColumn->getDouble(0) == Approx(1000.0));
 }