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);
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iter: A bson_iter_t. | ||
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data: A buffer to initialize with. This is not validated. | ||
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length: The length of data in bytes. This is not validated. | ||
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offset: The offset of the field to start iterating. This is not validated. This should be an offset previously obtained from bson_iter_offset(). | ||
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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(). |
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:
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Saving the current field's key length with bson_iter_key_len() | ||
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Saving the current offset with bson_iter_offset() | ||
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Saving the data pointer of the iterated bson_t with bson_get_data() | ||
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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 true if the iter was successfully initialized.
SEE ALSO:
bson_iter_key_len()
bson_iter_offset()
bson_get_data()
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