DPL: revamp / remove Endian.h

C++20 (and even more so 23) has understanding of endianess.
No need to have a special wrapper include anymore.

Author: ktf

Framework/AnalysisSupport/src/TTreePlugin.cxx

@@ -12,7 +12,7 @@
 #include "Framework/RootArrowFilesystem.h"
 #include "Framework/Plugins.h"
 #include "Framework/Signpost.h"
-#include "Framework/Endian.h"
+#include "Framework/BigEndian.h"
 #include <TBufferFile.h>
 #include <TBufferIO.h>
 #include <arrow/buffer.h>
@@ -197,7 +197,7 @@ auto readValues = [](uint8_t* target, ReadOps& op, TBufferFile& rootBuffer) {
     }
     int size = readLast * op.listSize;
     readEntries += readLast;
-    swapCopy(target, rootBuffer.GetCurrent(), size, op.typeSize);
+    bigEndianCopy(target, rootBuffer.GetCurrent(), size, op.typeSize);
     target += (ptrdiff_t)(size * op.typeSize);
   }
 };
@@ -230,7 +230,7 @@ auto readVLAValues = [](uint8_t* target, ReadOps& op, ReadOps const& offsetOp, T
     auto readLast = op.branch->GetBulkRead().GetEntriesSerialized(readEntries, rootBuffer);
     int size = offsets[readEntries + readLast] - offsets[readEntries];
     readEntries += readLast;
-    swapCopy(target, rootBuffer.GetCurrent(), size, op.typeSize);
+    bigEndianCopy(target, rootBuffer.GetCurrent(), size, op.typeSize);
     target += (ptrdiff_t)(size * op.typeSize);
   }
 };
@@ -581,7 +581,8 @@ auto readOffsets = [](ReadOps& op, TBufferFile& rootBuffer) {
     readEntries += readLast;
     for (auto i = 0; i < readLast; ++i) {
       offsets[count++] = (int)offset;
-      offset += swap32_(reinterpret_cast<uint32_t*>(rootBuffer.GetCurrent())[i]);
+      uint32_t raw = reinterpret_cast<uint32_t*>(rootBuffer.GetCurrent())[i];
+      offset += (std::endian::native == std::endian::little) ? __builtin_bswap32(raw) : raw;
     }
   }
   offsets[count] = (int)offset;

Framework/AnalysisSupport/src/TableTreeHelpers.cxx

@@ -10,7 +10,6 @@
 // or submit itself to any jurisdiction.
 #include "Framework/TableTreeHelpers.h"
 #include "Framework/Logger.h"
-#include "Framework/Endian.h"
 #include "Framework/Signpost.h"
 
 #include <arrow/dataset/file_base.h>

Framework/Core/src/FragmentToBatch.cxx

@@ -10,7 +10,6 @@
 // or submit itself to any jurisdiction.
 #include "Framework/FragmentToBatch.h"
 #include "Framework/Logger.h"
-#include "Framework/Endian.h"
 #include "Framework/Signpost.h"
 
 #include <arrow/dataset/file_base.h>

Framework/Core/src/HTTPParser.cxx

@@ -54,7 +54,7 @@ void encode_websocket_frames(std::vector<uv_buf_t>& outputs, char const* src, si
   int maskSize = mask ? 4 : 0;
 
   if (size < 126) {
-    headerSize = sizeof(WebSocketFrameTiny);
+    headerSize = sizeof(WebSocketFrameTiny<std::endian::native>);
     // Allocate a new page if we do not fit in the current one
     if (outputs.empty() || outputs.back().len > WebSocketConstants::MaxChunkSize || (size + maskSize + headerSize) > (WebSocketConstants::MaxChunkSize - outputs.back().len)) {
       char* chunk = (char*)malloc(WebSocketConstants::MaxChunkSize);
@@ -64,11 +64,11 @@ void encode_websocket_frames(std::vector<uv_buf_t>& outputs, char const* src, si
     // Reposition the buffer to the end of the current page
     buffer = buf.base + buf.len;
     buf.len += headerSize + size + maskSize;
-    WebSocketFrameTiny* header = (WebSocketFrameTiny*)buffer;
+    auto* header = (WebSocketFrameTiny<std::endian::native>*)buffer;
     memset(buffer, 0, headerSize);
     header->len = size;
   } else if (size < 1 << 16) {
-    headerSize = sizeof(WebSocketFrameShort);
+    headerSize = sizeof(WebSocketFrameShort<std::endian::native>);
     // Allocate a new page if we do not fit in the current one
     if (outputs.empty() || outputs.back().len > WebSocketConstants::MaxChunkSize || (size + maskSize + headerSize) > (WebSocketConstants::MaxChunkSize - outputs.back().len)) {
       char* chunk = (char*)malloc(WebSocketConstants::MaxChunkSize);
@@ -78,24 +78,24 @@ void encode_websocket_frames(std::vector<uv_buf_t>& outputs, char const* src, si
     // Reposition the buffer to the end of the current page
     buffer = buf.base + buf.len;
     buf.len += headerSize + size + maskSize;
-    WebSocketFrameShort* header = (WebSocketFrameShort*)buffer;
+    auto* header = (WebSocketFrameShort<std::endian::native>*)buffer;
     memset(buffer, 0, headerSize);
     header->len = 126;
     header->len16 = htons(size);
   } else {
     // For larger messages we do standalone allocation
     // so that the message does not need to be sent in multiple chunks
-    headerSize = sizeof(WebSocketFrameHuge);
+    headerSize = sizeof(WebSocketFrameHuge<std::endian::native>);
     buffer = (char*)malloc(headerSize + maskSize + size);
-    WebSocketFrameHuge* header = (WebSocketFrameHuge*)buffer;
+    auto* header = (WebSocketFrameHuge<std::endian::native>*)buffer;
     memset(buffer, 0, headerSize);
     header->len = 127;
-    header->len64 = htonll(size);
+    header->len64 = (std::endian::native == std::endian::little) ? __builtin_bswap64(size) : size;
     outputs.push_back(uv_buf_init(buffer, size + maskSize + headerSize));
   }
   size_t fullHeaderSize = maskSize + headerSize;
   startPayload = buffer + fullHeaderSize;
-  WebSocketFrameTiny* header = (WebSocketFrameTiny*)buffer;
+  auto* header = (WebSocketFrameTiny<std::endian::native>*)buffer;
   header->fin = 1;
   header->opcode = (unsigned char)opcode; // binary or text for now
   // Mask is right before payload.
@@ -143,7 +143,7 @@ void decode_websocket(char* start, size_t size, WebSocketHandler& handler)
   handler.beginChunk();
   // The + 2 is there because we need at least 2 bytes.
   while (cur - start < size) {
-    WebSocketFrameTiny* header = (WebSocketFrameTiny*)cur;
+    auto* header = (WebSocketFrameTiny<std::endian::native>*)cur;
     size_t payloadSize = 0;
     size_t headerSize = 0;
     if ((cur + 2 - start >= size) ||
@@ -160,12 +160,12 @@ void decode_websocket(char* start, size_t size, WebSocketHandler& handler)
       payloadSize = header->len;
       headerSize = 2 + (header->mask ? 4 : 0);
     } else if (header->len == 126) {
-      WebSocketFrameShort* headerSmall = (WebSocketFrameShort*)cur;
+      auto* headerSmall = (WebSocketFrameShort<std::endian::native>*)cur;
       payloadSize = ntohs(headerSmall->len16);
       headerSize = 2 + 2 + (header->mask ? 4 : 0);
     } else if (header->len == 127) {
-      WebSocketFrameHuge* headerSmall = (WebSocketFrameHuge*)cur;
-      payloadSize = ntohll(headerSmall->len64);
+      auto* headerSmall = (WebSocketFrameHuge<std::endian::native>*)cur;
+      payloadSize = (std::endian::native == std::endian::little) ? __builtin_bswap64(headerSmall->len64) : headerSmall->len64;
       headerSize = 2 + 8 + (header->mask ? 4 : 0);
     }
     size_t availableSize = size - (cur - start);

Framework/Core/src/HTTPParser.h

@@ -12,7 +12,8 @@
 #ifndef O2_FRAMEWORK_HTTPPARSER_H_
 #define O2_FRAMEWORK_HTTPPARSER_H_
 
-#include "Framework/Endian.h"
+#include <bit>
+#include <cstdint>
 #include <fmt/format.h>
 #include <uv.h>
 #include <string>
@@ -22,71 +23,82 @@
 namespace o2::framework
 {
 
-struct __attribute__((__packed__)) WebSocketFrameTiny {
-#if O2_HOST_BYTE_ORDER == O2_LITTLE_ENDIAN
+template <std::endian E>
+struct __attribute__((__packed__)) WebSocketFrameTiny;
+
+template <>
+struct __attribute__((__packed__)) WebSocketFrameTiny<std::endian::little> {
   unsigned char opcode : 4;
   unsigned char rsv3 : 1;
   unsigned char rsv2 : 1;
   unsigned char rsv1 : 1;
   unsigned char fin : 1;
   unsigned char len : 7;
   unsigned char mask : 1;
-#elif O2_HOST_BYTE_ORDER == O2_BIG_ENDIAN
+};
+
+template <>
+struct __attribute__((__packed__)) WebSocketFrameTiny<std::endian::big> {
   unsigned char fin : 1;
   unsigned char rsv1 : 1;
   unsigned char rsv2 : 1;
   unsigned char rsv3 : 1;
   unsigned char opcode : 4;
   unsigned char mask : 1;
   unsigned char len : 7;
-#else
-#error Uknown endiannes
-#endif
 };
 
-struct __attribute__((__packed__)) WebSocketFrameShort {
-#if O2_HOST_BYTE_ORDER == O2_LITTLE_ENDIAN
+template <std::endian E>
+struct __attribute__((__packed__)) WebSocketFrameShort;
+
+template <>
+struct __attribute__((__packed__)) WebSocketFrameShort<std::endian::little> {
   unsigned char opcode : 4;
   unsigned char rsv3 : 1;
   unsigned char rsv2 : 1;
   unsigned char rsv1 : 1;
   unsigned char fin : 1;
   unsigned char len : 7;
   unsigned char mask : 1;
-#elif O2_HOST_BYTE_ORDER == O2_BIG_ENDIAN
+  uint16_t len16;
+};
+
+template <>
+struct __attribute__((__packed__)) WebSocketFrameShort<std::endian::big> {
   unsigned char fin : 1;
   unsigned char rsv1 : 1;
   unsigned char rsv2 : 1;
   unsigned char rsv3 : 1;
   unsigned char opcode : 4;
   unsigned char mask : 1;
   unsigned char len : 7;
-#else
-#error Uknown endiannes
-#endif
   uint16_t len16;
 };
 
-struct __attribute__((__packed__)) WebSocketFrameHuge {
-#if O2_HOST_BYTE_ORDER == O2_LITTLE_ENDIAN
+template <std::endian E>
+struct __attribute__((__packed__)) WebSocketFrameHuge;
+
+template <>
+struct __attribute__((__packed__)) WebSocketFrameHuge<std::endian::little> {
   unsigned char opcode : 4;
   unsigned char rsv3 : 1;
   unsigned char rsv2 : 1;
   unsigned char rsv1 : 1;
   unsigned char fin : 1;
   unsigned char len : 7;
   unsigned char mask : 1;
-#elif O2_HOST_BYTE_ORDER == O2_BIG_ENDIAN
+  uint64_t len64;
+};
+
+template <>
+struct __attribute__((__packed__)) WebSocketFrameHuge<std::endian::big> {
   unsigned char fin : 1;
   unsigned char rsv1 : 1;
   unsigned char rsv2 : 1;
   unsigned char rsv3 : 1;
   unsigned char opcode : 4;
   unsigned char mask : 1;
   unsigned char len : 7;
-#else
-#error Uknown endiannes
-#endif
   uint64_t len64;
 };
 
@@ -138,9 +150,9 @@ struct WebSocketHandler {
   virtual ~WebSocketHandler() = default;
 
   /// Invoked when all the headers are received.
-  virtual void headers(std::map<std::string, std::string> const& headers){};
+  virtual void headers(std::map<std::string, std::string> const& headers) {};
   /// FIXME: not implemented
-  virtual void beginFragmentation(){};
+  virtual void beginFragmentation() {};
   /// Invoked when a frame it's parsed. Notice you do not own the data and you must
   /// not free the memory.
   virtual void frame(char const* frame, size_t s) {}
@@ -205,18 +217,18 @@ struct HTTPParser {
   std::string remaining;
   std::string error;
   std::vector<HTTPState> states;
-  virtual void method(std::string_view const& s){};
-  virtual void target(std::string_view const& s){};
-  virtual void version(std::string_view const& s){};
-  virtual void header(std::string_view const& k, std::string_view const& v){};
-  virtual void endHeaders(){};
+  virtual void method(std::string_view const& s) {};
+  virtual void target(std::string_view const& s) {};
+  virtual void version(std::string_view const& s) {};
+  virtual void header(std::string_view const& k, std::string_view const& v) {};
+  virtual void endHeaders() {};
   /// Invoked whenever we are parsing data.
   /// In order to allow for xoring (as required by the websocket standard)
   /// in place, we pass it as a mutable pointer.
-  virtual void body(char* data, size_t s){};
-  virtual void replyVersion(std::string_view const& s){};
-  virtual void replyCode(std::string_view const& s){};
-  virtual void replyMessage(std::string_view const& s){};
+  virtual void body(char* data, size_t s) {};
+  virtual void replyVersion(std::string_view const& s) {};
+  virtual void replyCode(std::string_view const& s) {};
+  virtual void replyMessage(std::string_view const& s) {};
 };
 
 struct HTTPParserHelpers {

Framework/Foundation/CMakeLists.txt

@@ -32,7 +32,8 @@ add_executable(o2-test-framework-foundation
                test/test_CallbackRegistry.cxx
                test/test_CompilerBuiltins.cxx
                #               test/test_Signpost.cxx
-               test/test_RuntimeError.cxx)
+               test/test_RuntimeError.cxx
+               test/test_BigEndian.cxx)
 target_link_libraries(o2-test-framework-foundation PRIVATE O2::FrameworkFoundation)
 target_link_libraries(o2-test-framework-foundation PRIVATE O2::Catch2)
 
@@ -65,4 +66,10 @@ install(TARGETS o2-log RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
 add_test(NAME framework:foundation COMMAND o2-test-framework-foundation)
 
+add_executable(o2-benchmark-framework-BigEndian
+               test/benchmark_BigEndian.cxx)
+target_link_libraries(o2-benchmark-framework-BigEndian
+                      PRIVATE O2::FrameworkFoundation benchmark::benchmark)
+set_property(TARGET o2-benchmark-framework-BigEndian PROPERTY RUNTIME_OUTPUT_DIRECTORY ${outdir})
+
 add_subdirectory(3rdparty)

Framework/Foundation/include/Framework/BigEndian.h

@@ -0,0 +1,64 @@
+// Copyright 2019-2026 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+#ifndef O2_FRAMEWORK_BIGENDIAN_H_
+#define O2_FRAMEWORK_BIGENDIAN_H_
+
+#include <bit>
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+
+namespace o2::framework
+{
+
+/// Copy @a count elements of @a typeSize bytes each from big-endian @a src
+/// into native byte order at @a dest. For typeSize == 1 or on big-endian
+/// platforms this reduces to a plain memcpy. @a dest and @a src must not overlap.
+inline void bigEndianCopy(void* dest, const void* src, int count, size_t typeSize)
+{
+  auto const totalBytes = static_cast<size_t>(count) * typeSize;
+  if constexpr (std::endian::native == std::endian::big) {
+    std::memcpy(dest, src, totalBytes);
+    return;
+  }
+  switch (typeSize) {
+    case 2: {
+      auto* p = static_cast<uint16_t*>(dest);
+      auto* q = static_cast<const uint16_t*>(src);
+      for (int i = 0; i < count; ++i) {
+        p[i] = __builtin_bswap16(q[i]);
+      }
+      return;
+    }
+    case 4: {
+      auto* p = static_cast<uint32_t*>(dest);
+      auto* q = static_cast<const uint32_t*>(src);
+      for (int i = 0; i < count; ++i) {
+        p[i] = __builtin_bswap32(q[i]);
+      }
+      return;
+    }
+    case 8: {
+      auto* p = static_cast<uint64_t*>(dest);
+      auto* q = static_cast<const uint64_t*>(src);
+      for (int i = 0; i < count; ++i) {
+        p[i] = __builtin_bswap64(q[i]);
+      }
+      return;
+    }
+  }
+  std::memcpy(dest, src, totalBytes);
+}
+
+} // namespace o2::framework
+
+#endif // O2_FRAMEWORK_BIGENDIAN_H_