NAME¶bson_iter_init_from_data_at_offset - bson_iter_init_from_data_at_offset()
bool bson_iter_init_from_data_at_offset (bson_iter_t *iter, const uint8_t *data, size_t length, uint32_t offset, uint32_t keylen);
- iter: A bson_iter_t.
- data: A buffer to initialize with. This is not validated.
- length: The length of data in bytes. This is not validated.
- offset: The offset of the field to start iterating. This is not validated. This should be an offset previously obtained from bson_iter_offset().
- keylen: The string length of the key of the field to start iterating. This is not validated. This should be a length previously obtained from bson_iter_key_len().
DESCRIPTION¶Creates a bson_iter_t and starts iteration on a field at the offset.
bson_iter_init_from_data_at_offset is useful for situations where the progress of a bson_iter_t must be saved and restored without relying on the bson_iter_t data layout. Saving the progress could be accomplished by:
- Saving the current field's key length with bson_iter_key_len()
- Saving the current offset with bson_iter_offset()
- Saving the data pointer of the iterated bson_t with bson_get_data()
- Saving the data length of the iterated bson_t with the len struct field
Then later, these saved values can be passed to bson_iter_init_from_data_at_offset() to reconstruct the bson_iter_t in constant time.
RETURNS¶Returns true if the iter was successfully initialized.
COPYRIGHT¶2017-present, MongoDB, Inc
|July 31, 2020||1.17.0|