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BSON_ITER_INIT_FROM_DATA_AT_OFFSET(3) | Libbson | 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.
SEE ALSO¶
- bson_iter_key_len()
- bson_iter_offset()
- bson_get_data()
RETURNS¶
Returns true if the iter was successfully initialized.AUTHOR¶
MongoDB, IncCOPYRIGHT¶
2017-present, MongoDB, IncFebruary 23, 2019 | 1.14.0 |