pub struct DictionaryTracker {
written: HashMap<i64, ArrayData>,
dict_ids: Vec<i64>,
error_on_replacement: bool,
}
Expand description
Keeps track of dictionaries that have been written, to avoid emitting the same dictionary multiple times.
Can optionally error if an update to an existing dictionary is attempted, which
isn’t allowed in the FileWriter
.
Fields§
§written: HashMap<i64, ArrayData>
§dict_ids: Vec<i64>
§error_on_replacement: bool
Implementations§
Source§impl DictionaryTracker
impl DictionaryTracker
Sourcepub fn new(error_on_replacement: bool) -> Self
pub fn new(error_on_replacement: bool) -> Self
Create a new DictionaryTracker
.
If error_on_replacement
is true, an error will be generated if an update to an
existing dictionary is attempted.
Sourcepub fn next_dict_id(&mut self) -> i64
pub fn next_dict_id(&mut self) -> i64
Record and return the next dictionary ID.
Sourcepub fn dict_id(&mut self) -> &[i64]
pub fn dict_id(&mut self) -> &[i64]
Return the sequence of dictionary IDs in the order they should be observed while traversing the schema
Sourcepub fn insert(
&mut self,
dict_id: i64,
column: &ArrayRef,
) -> Result<bool, ArrowError>
👎Deprecated since 56.1.0: Use insert_column
instead
pub fn insert( &mut self, dict_id: i64, column: &ArrayRef, ) -> Result<bool, ArrowError>
insert_column
insteadKeep track of the dictionary with the given ID and values. Behavior:
- If this ID has been written already and has the same data, return
Ok(false)
to indicate that the dictionary was not actually inserted (because it’s already been seen). - If this ID has been written already but with different data, and this tracker is configured to return an error, return an error.
- If the tracker has not been configured to error on replacement or this dictionary
has never been seen before, return
Ok(true)
to indicate that the dictionary was just inserted.
Sourcepub fn insert_column(
&mut self,
dict_id: i64,
column: &ArrayRef,
dict_handling: DictionaryHandling,
) -> Result<DictionaryUpdate, ArrowError>
pub fn insert_column( &mut self, dict_id: i64, column: &ArrayRef, dict_handling: DictionaryHandling, ) -> Result<DictionaryUpdate, ArrowError>
Keep track of the dictionary with the given ID and values. The return
value indicates what, if any, update to the internal map took place
and how it should be interpreted based on the dict_handling
parameter.
§Returns
Ok(Dictionary::New)
- If the dictionary was not previously writtenOk(Dictionary::Replaced)
- If the dictionary was previously written with completely different data, or if the data is a delta of the existing, but withdict_handling
set toDictionaryHandling::Resend
Ok(Dictionary::Delta)
- If the dictionary was previously written, but the new data is a delta of the old and thedict_handling
is set toDictionaryHandling::Delta
Err(e)
- If the dictionary was previously written with different data, anderror_on_replacement
is set totrue
.