BSON_ITER_INIT_FROM_DATA_AT_OFFSET(3)

NAME
bson_iter_init_from_data_at_offset - bson_iter_init_from_data_at_offset()

SYNOPSIS

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);

PARAMETERS

•   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.

SEE ALSO:
bson_iter_key_len()

bson_iter_offset()

bson_get_data()

AUTHOR
MongoDB, Inc

COPYRIGHT
2017-present, MongoDB, Inc