Minor modifications

dbms/src/IO/ReadHelpers.h

 #pragma once
 
+#include <byteswap.h>
 #include <cmath>
 #include <cstring>
 #include <limits>
@@ -746,6 +747,23 @@ inline void readBinary(Decimal128 & x, ReadBuffer & buf) { readPODBinary(x, buf)
 inline void readBinary(LocalDate & x, ReadBuffer & buf) { readPODBinary(x, buf); }
 
 
+template <typename T>
+inline std::enable_if_t<is_arithmetic_v<T> && (sizeof(T) <= 8), void>
+readBinaryBigEndian(T & x, ReadBuffer & buf)    /// Assuming little endian architecture.
+{
+    readPODBinary(x, buf);
+
+    if constexpr (sizeof(x) == 1)
+        return;
+    else if constexpr (sizeof(x) == 2)
+        x = bswap_16(x);
+    else if constexpr (sizeof(x) == 4)
+        x = bswap_32(x);
+    else if constexpr (sizeof(x) == 8)
+        x = bswap_64(x);
+}
+
+
 /// Generic methods to read value in text tab-separated format.
 template <typename T>
 inline std::enable_if_t<is_integral_v<T>, void>

dbms/src/Processors/Formats/Impl/AvroRowInputFormat.cpp

@@ -553,16 +553,16 @@ private:
 
 static uint32_t readConfluentSchemaId(ReadBuffer & in)
 {
-    Poco::Buffer<char> buf(5);
-    in.readStrict(buf.begin(), buf.capacity());
-    Poco::MemoryBinaryReader binary_reader(buf, Poco::BinaryReader::BIG_ENDIAN_BYTE_ORDER);
-
     uint8_t magic;
     uint32_t schema_id;
-    binary_reader >> magic >> schema_id;
+
+    readBinaryBigEndian(magic, in);
+    readBinaryBigEndian(schema_id, in);
+
     if (magic != 0x00)
     {
-        throw Exception("Invalid magic byte", ErrorCodes::INCORRECT_DATA);
+        throw Exception("Invalid magic byte before AvroConfluent schema identifier."
+            " Must be zero byte, found " + std::to_string(int(magic)) + " instead", ErrorCodes::INCORRECT_DATA);
     }
 
     return schema_id;
@@ -577,7 +577,6 @@ AvroConfluentRowInputFormat::AvroConfluentRowInputFormat(
     , decoder(avro::binaryDecoder())
 
 {
-    (void)format_settings_;
     decoder->init(*input_stream);
 }