• libbson 1.13.1 »
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• bson_iter_t

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.