BSON_ITER_INIT_FROM_DATA_AT_OFFSET

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