protobuf/upb/reflection.c

#include "upb/reflection.h"

#include <string.h>
#include "upb/table.int.h"
#include "upb/msg.h"

#include "upb/port_def.inc"

bool upb_fieldtype_mapkeyok(upb_fieldtype_t type) {
  return type == UPB_TYPE_BOOL || type == UPB_TYPE_INT32 ||
         type == UPB_TYPE_UINT32 || type == UPB_TYPE_INT64 ||
         type == UPB_TYPE_UINT64 || type == UPB_TYPE_STRING;
}

#define PTR_AT(msg, ofs, type) (type*)((char*)msg + ofs)
#define VOIDPTR_AT(msg, ofs) PTR_AT(msg, ofs, void)
#define ENCODE_MAX_NESTING 64
#define CHECK_TRUE(x) if (!(x)) { return false; }

/** upb_msgval ****************************************************************/

#if 0
/* These functions will generate real memcpy() calls on ARM sadly, because
 * the compiler assumes they might not be aligned. */

static upb_msgval upb_msgval_read(const void *p, size_t ofs,
                                  uint8_t size) {
  upb_msgval val;
  p = (char*)p + ofs;
  memcpy(&val, p, size);
  return val;
}

static void upb_msgval_write(void *p, size_t ofs, upb_msgval val,
                             uint8_t size) {
  p = (char*)p + ofs;
  memcpy(p, &val, size);
}

static size_t upb_msgval_sizeof(upb_descriptortype_t type) {
  static uint8_t sizes[] = {
    0,  /* none */
    8,  /* UPB_DESCRIPTOR_TYPE_DOUBLE   = 1 */
    4,  /* UPB_DESCRIPTOR_TYPE_FLOAT    = 2 */
    8,  /* UPB_DESCRIPTOR_TYPE_INT64    = 3 */
    8,  /* UPB_DESCRIPTOR_TYPE_UINT64   = 4 */
    4,  /* UPB_DESCRIPTOR_TYPE_INT32    = 5 */
    8,  /* UPB_DESCRIPTOR_TYPE_FIXED64  = 6 */
    4,  /* UPB_DESCRIPTOR_TYPE_FIXED32  = 7 */
    1,  /* UPB_DESCRIPTOR_TYPE_BOOL     = 8 */
    sizeof(upb_strview),  /* UPB_DESCRIPTOR_TYPE_STRING   = 9 */
    sizeof(void*),  /* UPB_DESCRIPTOR_TYPE_GROUP    = 11 */
    sizeof(void*),  /* UPB_DESCRIPTOR_TYPE_MESSAGE  = 12 */
    sizeof(upb_strview),  /* UPB_DESCRIPTOR_TYPE_BYTES    = 13 */
    4,  /* UPB_DESCRIPTOR_TYPE_UINT32   = 14 */
    4,  /* UPB_DESCRIPTOR_TYPE_ENUM     = 15 */
    4,  /* UPB_DESCRIPTOR_TYPE_SFIXED32 = 16 */
    8,  /* UPB_DESCRIPTOR_TYPE_SFIXED64 = 17 */
    4,  /* UPB_DESCRIPTOR_TYPE_SINT32   = 18 */
    8,  /* UPB_DESCRIPTOR_TYPE_SINT64   = 19 */
  };
  UPB_ASSERT(type < sizeof(sizes));
  return sizes[type];
}

static size_t upb_msgval_sizeof2(upb_fieldtype_t type) {
  static uint8_t sizes[] = {
    0,  /* none */
    1,  /* UPB_TYPE_BOOL     = 1, */
    4,  /* UPB_TYPE_FLOAT    = 2, */
    4,  /* UPB_TYPE_INT32    = 3, */
    4,  /* UPB_TYPE_UINT32   = 4, */
    4,  /* UPB_TYPE_ENUM     = 5, */
    sizeof(upb_strview),  /* UPB_TYPE_STRING   = 6, */
    sizeof(upb_strview),  /* UPB_TYPE_BYTES    = 7, */
    sizeof(void*),  /* UPB_TYPE_MESSAGE  = 8, */
    8,  /* UPB_TYPE_DOUBLE   = 9, */
    8,  /* UPB_TYPE_INT64    = 10, */
    8,  /* UPB_TYPE_UINT64   = 11 */
  };
  UPB_ASSERT(type < sizeof(sizes));
  return sizes[type];
}

static uint8_t upb_msg_fieldsize(const upb_msglayout_field *field) {
  if (field->label == UPB_LABEL_REPEATED) {
    return sizeof(void*);
  } else {
    return upb_msgval_sizeof(field->descriptortype);
  }
}

/* TODO(haberman): this is broken right now because upb_msgval can contain
 * a char* / size_t pair, which is too big for a upb_value.  To fix this
 * we'll probably need to dynamically allocate a upb_msgval and store a
 * pointer to that in the tables for extensions/maps. */
static upb_value upb_toval(upb_msgval val) {
  upb_value ret;
  UPB_UNUSED(val);
  memset(&ret, 0, sizeof(upb_value));  /* XXX */
  return ret;
}

static upb_msgval upb_msgval_fromval(upb_value val) {
  upb_msgval ret;
  UPB_UNUSED(val);
  memset(&ret, 0, sizeof(upb_msgval));  /* XXX */
  return ret;
}

/** upb_msg *******************************************************************/

/* If we always read/write as a consistent type to each address, this shouldn't
 * violate aliasing.
 */
#define DEREF(msg, ofs, type) *PTR_AT(msg, ofs, type)

static const upb_msglayout_field *upb_msg_checkfield(int field_index,
                                                     const upb_msglayout *l) {
  UPB_ASSERT(field_index >= 0 && field_index < l->field_count);
  return &l->fields[field_index];
}

static bool upb_msg_inoneof(const upb_msglayout_field *field) {
  return field->presence < 0;
}

static uint32_t *upb_msg_oneofcase(const upb_msg *msg, int field_index,
                                   const upb_msglayout *l) {
  const upb_msglayout_field *field = upb_msg_checkfield(field_index, l);
  UPB_ASSERT(upb_msg_inoneof(field));
  return PTR_AT(msg, ~field->presence, uint32_t);
}

bool upb_msg_has(const upb_msg *msg,
                 int field_index,
                 const upb_msglayout *l) {
  const upb_msglayout_field *field = upb_msg_checkfield(field_index, l);

  UPB_ASSERT(field->presence);

  if (upb_msg_inoneof(field)) {
    /* Oneofs are set when the oneof number is set to this field. */
    return *upb_msg_oneofcase(msg, field_index, l) == field->number;
  } else {
    /* Other fields are set when their hasbit is set. */
    uint32_t hasbit = field->presence;
    return DEREF(msg, hasbit / 8, char) | (1 << (hasbit % 8));
  }
}

upb_msgval upb_msg_get(const upb_msg *msg, int field_index,
                       const upb_msglayout *l) {
  const upb_msglayout_field *field = upb_msg_checkfield(field_index, l);
  int size = upb_msg_fieldsize(field);
  return upb_msgval_read(msg, field->offset, size);
}

void upb_msg_set(upb_msg *msg, int field_index, upb_msgval val,
                 const upb_msglayout *l) {
  const upb_msglayout_field *field = upb_msg_checkfield(field_index, l);
  int size = upb_msg_fieldsize(field);
  upb_msgval_write(msg, field->offset, val, size);
}

#endif

/** upb_array *****************************************************************/

size_t upb_array_size(const upb_array *arr) {
  return arr->len;
}

upb_msgval upb_array_get(const upb_array *arr, size_t i) {
  UPB_ASSERT(i < arr->len);
  const char* data = _upb_array_constptr(arr);
  int elem_size_lg2 = arr->data & 7;
  upb_msgval ret;

  switch (elem_size_lg2) {
    case 0:
      ret.bool_val = *PTR_AT(data, i, bool);
      break;
    case 2:
      memcpy(&ret, data + i * 4, 4);
      break;
    case 3:
      memcpy(&ret, data + i * 8, 8);
      break;
    case 4:
      memcpy(&ret, data + i * 16, 16);
      break;
    default:
      UPB_UNREACHABLE();
  }

  return ret;
}

void upb_array_set(upb_array *arr, size_t i, upb_msgval val) {
  UPB_ASSERT(i < arr->len);
  char* data = _upb_array_ptr(arr);
  int elem_size_lg2 = arr->data & 7;

  switch (elem_size_lg2) {
    case 0:
      *PTR_AT(data, i, bool) = val.bool_val;
      break;
    case 2:
      memcpy(data + i * 4, &val, 4);
      break;
    case 3:
      memcpy(data + i * 8, &val, 8);
      break;
    case 4:
      memcpy(data + i * 16, &val, 16);
      break;
    default:
      UPB_UNREACHABLE();
  }
}

/* Resizes the array to the given size, reallocating if necessary, and returns a
 * pointer to the new array elements. */
bool upb_array_resize(upb_array *arr, size_t size, upb_arena *arena) {
  return _upb_array_realloc(arr, size, arena);
}

#if 0

/** upb_map *******************************************************************/

static void upb_map_tokey(upb_descriptortype_t type, upb_msgval *key,
                          const char **out_key, size_t *out_len) {
  switch (type) {
    case UPB_DESCRIPTOR_TYPE_BYTES:
    case UPB_DESCRIPTOR_TYPE_STRING:
      /* Point to string data of the input key. */
      *out_key = key->str.data;
      *out_len = key->str.size;
      return;
    case UPB_DESCRIPTOR_TYPE_BOOL:
    case UPB_DESCRIPTOR_TYPE_INT32:
    case UPB_DESCRIPTOR_TYPE_SINT32:
    case UPB_DESCRIPTOR_TYPE_SFIXED32:
    case UPB_DESCRIPTOR_TYPE_FIXED32:
    case UPB_DESCRIPTOR_TYPE_UINT32:
    case UPB_DESCRIPTOR_TYPE_INT64:
    case UPB_DESCRIPTOR_TYPE_SINT64:
    case UPB_DESCRIPTOR_TYPE_SFIXED64:
    case UPB_DESCRIPTOR_TYPE_FIXED64:
    case UPB_DESCRIPTOR_TYPE_UINT64:
      /* Point to the key itself.  XXX: big-endian. */
      *out_key = (const char*)key;
      *out_len = upb_msgval_sizeof(type);
      return;
    case UPB_DESCRIPTOR_TYPE_DOUBLE:
    case UPB_DESCRIPTOR_TYPE_ENUM:
    case UPB_DESCRIPTOR_TYPE_FLOAT:
    case UPB_DESCRIPTOR_TYPE_MESSAGE:
    case UPB_DESCRIPTOR_TYPE_GROUP:
      UPB_UNREACHABLE();  /* Cannot be a map key. */
  }
  UPB_UNREACHABLE();
}

static upb_msgval upb_map_fromkey(upb_descriptortype_t type, const char *key,
                                  size_t len) {
  switch (type) {
    case UPB_DESCRIPTOR_TYPE_BYTES:
    case UPB_DESCRIPTOR_TYPE_STRING:
      return upb_msgval_makestr(key, len);
    case UPB_DESCRIPTOR_TYPE_BOOL:
    case UPB_DESCRIPTOR_TYPE_INT32:
    case UPB_DESCRIPTOR_TYPE_SINT32:
    case UPB_DESCRIPTOR_TYPE_SFIXED32:
    case UPB_DESCRIPTOR_TYPE_FIXED32:
    case UPB_DESCRIPTOR_TYPE_UINT32:
    case UPB_DESCRIPTOR_TYPE_INT64:
    case UPB_DESCRIPTOR_TYPE_SINT64:
    case UPB_DESCRIPTOR_TYPE_SFIXED64:
    case UPB_DESCRIPTOR_TYPE_FIXED64:
    case UPB_DESCRIPTOR_TYPE_UINT64:
      return upb_msgval_read(key, 0, upb_msgval_sizeof(type));
    case UPB_DESCRIPTOR_TYPE_DOUBLE:
    case UPB_DESCRIPTOR_TYPE_ENUM:
    case UPB_DESCRIPTOR_TYPE_FLOAT:
    case UPB_DESCRIPTOR_TYPE_MESSAGE:
    case UPB_DESCRIPTOR_TYPE_GROUP:
      UPB_UNREACHABLE();  /* Cannot be a map key. */
  }
  UPB_UNREACHABLE();
}

bool upb_map_get(const upb_map *map, upb_msgval key, upb_msgval *val,
                 const upb_msglayout *layout) {
  upb_value tabval;
  const char *key_str;
  size_t key_len;
  bool ret;

  upb_map_tokey(layout->fields[0].descriptortype, &key, &key_str, &key_len);
  ret = upb_strtable_lookup2(&map->table, key_str, key_len, &tabval);
  if (ret) {
    memcpy(val, &tabval, sizeof(tabval));
  }

  return ret;
}

bool upb_map_set(upb_map *map, upb_msgval key, upb_msgval val,
                 const upb_msglayout *layout, upb_arena *arena) {
  const char *key_str;
  size_t key_len;
  upb_value tabval = upb_toval(val);
  upb_value removedtabval;
  upb_alloc *a = upb_arena_alloc(arena);

  upb_map_tokey(layout->fields[0].descriptortype, &key, &key_str, &key_len);

  /* TODO(haberman): add overwrite operation to minimize number of lookups. */
  if (upb_strtable_lookup2(&map->table, key_str, key_len, NULL)) {
    upb_strtable_remove3(&map->table, key_str, key_len, &removedtabval, a);
  }

  return upb_strtable_insert3(&map->table, key_str, key_len, tabval, a);
}

bool upb_map_del(upb_map *map, upb_msgval key, const upb_msglayout *layout,
                 upb_arena *arena) {
  const char *key_str;
  size_t key_len;
  upb_alloc *a = upb_arena_alloc(arena);

  upb_map_tokey(layout->fields[0].descriptortype, &key, &key_str, &key_len);
  return upb_strtable_remove3(&map->table, key_str, key_len, NULL, a);
}

/** upb_mapiter ***************************************************************/

struct upb_mapiter {
  upb_strtable_iter iter;
  upb_descriptortype_t key_type;
};

size_t upb_mapiter_sizeof(void) {
  return sizeof(upb_mapiter);
}

void upb_mapiter_begin(upb_mapiter *i, const upb_msglayout *layout,
                       const upb_map *map) {
  upb_strtable_begin(&i->iter, &map->table);
  i->key_type = layout->fields[0].descriptortype;
}

upb_mapiter *upb_mapiter_new(const upb_map *map, const upb_msglayout *layout,
                             upb_alloc *a) {
  upb_mapiter *ret = upb_malloc(a, upb_mapiter_sizeof());

  if (!ret) {
    return NULL;
  }

  upb_mapiter_begin(ret, layout, map);
  return ret;
}

void upb_mapiter_free(upb_mapiter *i, upb_alloc *a) {
  upb_free(a, i);
}

void upb_mapiter_next(upb_mapiter *i) {
  upb_strtable_next(&i->iter);
}

bool upb_mapiter_done(const upb_mapiter *i) {
  return upb_strtable_done(&i->iter);
}

upb_msgval upb_mapiter_key(const upb_mapiter *i) {
  return upb_map_fromkey(i->key_type, upb_strtable_iter_key(&i->iter),
                         upb_strtable_iter_keylength(&i->iter));
}

upb_msgval upb_mapiter_value(const upb_mapiter *i) {
  return upb_msgval_fromval(upb_strtable_iter_value(&i->iter));
}

void upb_mapiter_setdone(upb_mapiter *i) {
  upb_strtable_iter_setdone(&i->iter);
}

bool upb_mapiter_isequal(const upb_mapiter *i1, const upb_mapiter *i2) {
  return upb_strtable_iter_isequal(&i1->iter, &i2->iter);
}

#endif