upb/message/copy.c

// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC.  All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

#include "upb/message/copy.h"

#include <stdbool.h>
#include <stdint.h>
#include <string.h>

#include "upb/base/descriptor_constants.h"
#include "upb/base/string_view.h"
#include "upb/hash/common.h"
#include "upb/hash/int_table.h"
#include "upb/hash/str_table.h"
#include "upb/mem/arena.h"
#include "upb/message/accessors.h"
#include "upb/message/array.h"
#include "upb/message/internal/accessors.h"
#include "upb/message/internal/array.h"
#include "upb/message/internal/extension.h"
#include "upb/message/internal/map.h"
#include "upb/message/internal/message.h"
#include "upb/message/internal/types.h"
#include "upb/message/map.h"
#include "upb/message/message.h"
#include "upb/mini_table/extension.h"
#include "upb/mini_table/field.h"
#include "upb/mini_table/internal/field.h"
#include "upb/mini_table/internal/size_log2.h"
#include "upb/mini_table/message.h"

// Must be last.
#include "upb/port/def.inc"

static upb_StringView upb_Clone_StringView(upb_StringView str,
                                           upb_Arena* arena) {
  if (str.size == 0) {
    return upb_StringView_FromDataAndSize(NULL, 0);
  }
  void* cloned_data = upb_Arena_Malloc(arena, str.size);
  if (cloned_data == NULL) {
    return upb_StringView_FromDataAndSize(NULL, 0);
  }
  memcpy(cloned_data, str.data, str.size);
  return upb_StringView_FromDataAndSize(cloned_data, str.size);
}

static bool upb_Clone_MessageValue(void* value, upb_CType value_type,
                                   const upb_MiniTable* sub, upb_Arena* arena) {
  switch (value_type) {
    case kUpb_CType_Bool:
    case kUpb_CType_Float:
    case kUpb_CType_Int32:
    case kUpb_CType_UInt32:
    case kUpb_CType_Enum:
    case kUpb_CType_Double:
    case kUpb_CType_Int64:
    case kUpb_CType_UInt64:
      return true;
    case kUpb_CType_String:
    case kUpb_CType_Bytes: {
      upb_StringView source = *(upb_StringView*)value;
      size_t size = source.size;
      void* cloned_data = upb_Arena_Malloc(arena, size);
      if (cloned_data == NULL) {
        return false;
      }
      *(upb_StringView*)value =
          upb_StringView_FromDataAndSize(cloned_data, size);
      memcpy(cloned_data, source.data, size);
      return true;
    } break;
    case kUpb_CType_Message: {
      UPB_ASSERT(sub);
      const upb_Message* source = *(upb_Message**)value;
      UPB_ASSERT(source);
      upb_Message* clone = upb_Message_DeepClone(source, sub, arena);
      *(upb_Message**)value = clone;
      return clone != NULL;
    } break;
  }
  UPB_UNREACHABLE();
}

static bool upb_Clone_MapValue(upb_value* tabval, size_t map_val_size,
                               upb_CType value_field_type,
                               const upb_MiniTable* value_sub, upb_Arena* arena,
                               upb_value* cloned_tabval) {
  upb_MessageValue val;
  _upb_map_fromvalue(*tabval, &val, map_val_size);
  if (!upb_Clone_MessageValue(&val, value_field_type, value_sub, arena)) {
    return false;
  }
  *cloned_tabval = (upb_value){0};  // Initialize
  if (!_upb_map_tovalue(&val, map_val_size, cloned_tabval, arena)) {
    return false;
  }
  return true;
}

upb_Map* upb_Map_DeepClone(const upb_Map* map, upb_CType key_type,
                           upb_CType value_type,
                           const upb_MiniTable* map_entry_table,
                           upb_Arena* arena) {
  upb_Map* cloned_map = upb_Arena_Malloc(arena, sizeof(upb_Map));
  if (cloned_map == NULL) {
    return NULL;
  }
  cloned_map->key_size = map->key_size;
  cloned_map->val_size = map->val_size;
  cloned_map->UPB_PRIVATE(is_frozen) = false;
  cloned_map->UPB_PRIVATE(is_strtable) = map->UPB_PRIVATE(is_strtable);

  const upb_MiniTableField* value_field =
      upb_MiniTable_MapValue(map_entry_table);
  const upb_MiniTable* value_sub = upb_MiniTable_SubMessage(value_field);
  upb_CType value_field_type = upb_MiniTableField_CType(value_field);

  bool is_primitive = value_field_type != kUpb_CType_Message &&
                      value_field_type != kUpb_CType_String &&
                      value_field_type != kUpb_CType_Bytes;

  if (map->UPB_PRIVATE(is_strtable)) {
    if (!upb_strtable_copy(&cloned_map->t.strtable, &map->t.strtable, arena)) {
      return NULL;
    }
    if (!is_primitive) {
      intptr_t iter = UPB_STRTABLE_BEGIN;
      upb_StringView key;
      upb_value tabval;
      while (
          upb_strtable_next2(&cloned_map->t.strtable, &key, &tabval, &iter)) {
        upb_value cloned_tabval;
        if (!upb_Clone_MapValue(&tabval, map->val_size, value_field_type,
                                value_sub, arena, &cloned_tabval)) {
          return NULL;
        }
        upb_strtable_setentryvalue(&cloned_map->t.strtable, iter,
                                   cloned_tabval);
      }
    }
  } else {
    if (!upb_inttable_copy(&cloned_map->t.inttable, &map->t.inttable, arena)) {
      return NULL;
    }
    if (!is_primitive) {
      intptr_t iter = UPB_INTTABLE_BEGIN;
      uintptr_t key;
      upb_value tabval;
      while (upb_inttable_next(&cloned_map->t.inttable, &key, &tabval, &iter)) {
        upb_value cloned_tabval;
        if (!upb_Clone_MapValue(&tabval, map->val_size, value_field_type,
                                value_sub, arena, &cloned_tabval)) {
          return NULL;
        }
        upb_inttable_setentryvalue(&cloned_map->t.inttable, iter,
                                   cloned_tabval);
      }
    }
  }
  return cloned_map;
}

static upb_Map* upb_Message_Map_DeepClone(const upb_Map* map,
                                          const upb_MiniTable* mini_table,
                                          const upb_MiniTableField* f,
                                          upb_Message* clone,
                                          upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(clone));
  const upb_MiniTable* map_entry_table = upb_MiniTable_MapEntrySubMessage(f);
  UPB_ASSERT(map_entry_table);

  const upb_MiniTableField* key_field = upb_MiniTable_MapKey(map_entry_table);
  const upb_MiniTableField* value_field =
      upb_MiniTable_MapValue(map_entry_table);

  upb_Map* cloned_map = upb_Map_DeepClone(
      map, upb_MiniTableField_CType(key_field),
      upb_MiniTableField_CType(value_field), map_entry_table, arena);
  if (!cloned_map) {
    return NULL;
  }
  upb_Message_SetBaseField(clone, f, &cloned_map);
  return cloned_map;
}

upb_Array* upb_Array_DeepClone(const upb_Array* array, upb_CType value_type,
                               const upb_MiniTable* sub, upb_Arena* arena) {
  const size_t size = upb_Array_Size(array);
  const int lg2 = UPB_PRIVATE(_upb_CType_SizeLg2)(value_type);
  upb_Array* cloned_array = UPB_PRIVATE(_upb_Array_New)(arena, size, lg2);
  if (!cloned_array) {
    return NULL;
  }
  if (!UPB_PRIVATE(_upb_Array_ResizeUninitialized)(cloned_array, size, arena)) {
    return NULL;
  }
  for (size_t i = 0; i < size; ++i) {
    upb_MessageValue val = upb_Array_Get(array, i);
    if (!upb_Clone_MessageValue(&val, value_type, sub, arena)) {
      return NULL;
    }
    upb_Array_Set(cloned_array, i, val);
  }
  return cloned_array;
}

static bool upb_Message_Array_DeepClone(const upb_Array* array,
                                        const upb_MiniTable* mini_table,
                                        const upb_MiniTableField* field,
                                        upb_Message* clone, upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(clone));
  UPB_PRIVATE(_upb_MiniTableField_CheckIsArray)(field);
  upb_Array* cloned_array =
      upb_Array_DeepClone(array, upb_MiniTableField_CType(field),
                          upb_MiniTableField_CType(field) == kUpb_CType_Message
                              ? upb_MiniTable_GetSubMessageTable(field)
                              : NULL,
                          arena);
  if (!cloned_array) return false;

  // Clear out upb_Array* due to parent memcpy.
  upb_Message_SetBaseField(clone, field, &cloned_array);
  return true;
}

static bool upb_Clone_ExtensionValue(const upb_MiniTableField* field,
                                     const upb_Extension* source,
                                     upb_Extension* dest, upb_Arena* arena) {
  upb_MessageValue val = upb_Extension_GetValue(source);
  if (!upb_Clone_MessageValue(&val, upb_MiniTableField_CType(field),
                              upb_MiniTable_SubMessage(field), arena)) {
    return false;
  }
  upb_Extension_SetValue(dest, val);
  return true;
}

upb_Message* _upb_Message_Copy(upb_Message* dst, const upb_Message* src,
                               const upb_MiniTable* mini_table,
                               upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(dst));
  upb_StringView empty_string = upb_StringView_FromDataAndSize(NULL, 0);
  // Only copy message area skipping upb_Message_Internal.
  memcpy(dst + 1, src + 1, mini_table->UPB_PRIVATE(size) - sizeof(upb_Message));
  for (int i = 0; i < upb_MiniTable_FieldCount(mini_table); ++i) {
    const upb_MiniTableField* field =
        upb_MiniTable_GetFieldByIndex(mini_table, i);
    if (upb_MiniTableField_IsScalar(field)) {
      switch (upb_MiniTableField_CType(field)) {
        case kUpb_CType_Message: {
          const upb_Message* sub_message = upb_Message_GetMessage(src, field);
          if (sub_message != NULL) {
            const upb_MiniTable* sub_message_table =
                upb_MiniTable_GetSubMessageTable(field);
            upb_Message* dst_sub_message =
                upb_Message_DeepClone(sub_message, sub_message_table, arena);
            if (dst_sub_message == NULL) goto err;

            upb_Message_SetBaseFieldMessage(dst, field, dst_sub_message);
          }
        } break;
        case kUpb_CType_String:
        case kUpb_CType_Bytes: {
          upb_StringView str = upb_Message_GetString(src, field, empty_string);
          if (str.size != 0) {
            upb_StringView cloned_str = upb_Clone_StringView(str, arena);
            if (cloned_str.data == NULL) goto err;

            if (!upb_Message_SetString(dst, field, cloned_str, arena)) goto err;
          }
        } break;
        default:
          // Scalar, already copied.
          break;
      }
    } else {
      if (upb_MiniTableField_IsMap(field)) {
        const upb_Map* map = upb_Message_GetMap(src, field);
        if (map != NULL) {
          if (!upb_Message_Map_DeepClone(map, mini_table, field, dst, arena)) {
            goto err;
          }
        }
      } else {
        const upb_Array* array = upb_Message_GetArray(src, field);
        if (array != NULL) {
          if (!upb_Message_Array_DeepClone(array, mini_table, field, dst,
                                           arena)) {
            goto err;
          }
        }
      }
    }
  }
  // Clone extensions.
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(src);
  if (!in) return dst;

  for (size_t i = 0; i < in->size; i++) {
    upb_TaggedAuxPtr tagged_ptr = in->aux_data[i];
    if (upb_TaggedAuxPtr_IsExtension(tagged_ptr)) {
      // Clone a canonical or non-canonical upb_Extension*.
      const upb_Extension* msg_ext = upb_TaggedAuxPtr_Extension(tagged_ptr);
      const upb_MiniTableField* field = upb_Extension_MiniTableField(msg_ext);
      upb_Extension* dst_ext =
          UPB_PRIVATE(_upb_Message_GetOrCreateExtensionWithTag)(
              dst, upb_Extension_MiniTableExtension(msg_ext), arena,
              upb_TaggedAuxPtr_Type(tagged_ptr));
      if (!dst_ext) goto err;

      if (upb_MiniTableField_IsScalar(field)) {
        if (!upb_Clone_ExtensionValue(field, msg_ext, dst_ext, arena)) {
          goto err;
        }
      } else {
        // Extensions (canonical or non-canonical) cannot be maps.
        UPB_ASSERT(upb_MiniTableField_IsArray(field));
        const upb_Array* msg_array = upb_Extension_GetArray(msg_ext);
        UPB_ASSERT(msg_array);
        upb_Array* cloned_array =
            upb_Array_DeepClone(msg_array, upb_MiniTableField_CType(field),
                                upb_MiniTable_SubMessage(field), arena);
        if (!cloned_array) goto err;

        upb_Extension_SetArray(dst_ext, cloned_array);
      }
    } else if (upb_TaggedAuxPtr_IsUnknownStringView(tagged_ptr)) {
      // Clone an aliased or non-aliased unknown upb_StringView.
      upb_StringView* unknown = upb_TaggedPtrAux_StringViewRepr(tagged_ptr);
      // Make a copy into destination arena.
      if (!UPB_PRIVATE(_upb_Message_AddUnknown)(
              dst, unknown->data, unknown->size, arena, kUpb_AddUnknown_Copy)) {
        goto err;
      }
    }
  }
  return dst;

err:
  upb_Message_Clear(dst, mini_table);
  return NULL;
}

bool upb_Message_DeepCopy(upb_Message* dst, const upb_Message* src,
                          const upb_MiniTable* mini_table, upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(dst));
  upb_Message_Clear(dst, mini_table);
  return _upb_Message_Copy(dst, src, mini_table, arena) != NULL;
}

// Deep clones a message using the provided target arena.
//
// Returns NULL on failure.
upb_Message* upb_Message_DeepClone(const upb_Message* msg,
                                   const upb_MiniTable* m, upb_Arena* arena) {
  upb_Message* clone = upb_Message_New(m, arena);
  if (!clone) return NULL;
  return _upb_Message_Copy(clone, msg, m, arena);
}

// Performs a shallow copy.
bool upb_Message_ShallowCopy(upb_Message* dst, const upb_Message* src,
                             const upb_MiniTable* m, upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(dst));
  memcpy(dst, src, m->UPB_PRIVATE(size));

  return UPB_PRIVATE(_upb_Message_CopyInternal)(dst, src, arena);
}

// Performs a shallow clone.
upb_Message* upb_Message_ShallowClone(const upb_Message* msg,
                                      const upb_MiniTable* m,
                                      upb_Arena* arena) {
  upb_Message* clone = upb_Message_New(m, arena);
  if (!clone) return NULL;
  if (!upb_Message_ShallowCopy(clone, msg, m, arena)) return NULL;
  return clone;
}