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use std::collections::BTreeMap; use std::fs::File; use std::io::{Read, Seek}; use std::marker::PhantomData; use std::path::Path; use serde::de::DeserializeOwned; mod dbf; mod deserialize; mod error; mod model; mod value; use dbf::DbfReader; use deserialize::DbfDeserializer; pub use model::{Date, Timestamp}; pub use value::Value; pub fn read<P, T>( table_path: P, memo_path: Option<P>, ) -> Result<RecordIterator<File, T>, Box<dyn std::error::Error>> where P: AsRef<Path>, T: DeserializeOwned, { let table_file = File::open(table_path.as_ref())?; let memo_file = memo_path.map(File::open).transpose()?; DbfReader::from_reader(table_file, memo_file).map(RecordIterator::new) } pub fn read_values<P>( table_path: P, memo_path: Option<P>, ) -> Result<ValuesIterator<File>, Box<dyn std::error::Error>> where P: AsRef<Path>, { let table_file = File::open(table_path.as_ref())?; let memo_file = memo_path.map(File::open).transpose()?; DbfReader::from_reader(table_file, memo_file).map(|r| ValuesIterator { reader: r }) } pub struct RecordIterator<R, T> where R: Read + Seek, T: DeserializeOwned, { reader: DbfReader<R>, deserializer: DbfDeserializer, _type: PhantomData<T>, } impl<R: Read + Seek, T: DeserializeOwned> RecordIterator<R, T> { pub fn new(reader: DbfReader<R>) -> Self { let deserializer = DbfDeserializer::new(reader.fields().clone()); Self { reader, deserializer, _type: PhantomData, } } } impl<R: Read + Seek, T: DeserializeOwned> Iterator for RecordIterator<R, T> { type Item = Result<T, Box<dyn std::error::Error>>; fn next(&mut self) -> Option<Self::Item> { let values = match self.reader.next_record() { Ok(Some(val)) => val, Ok(None) => return None, Err(e) => return Some(Err(e)), }; self.deserializer.set_values(values); T::deserialize(&mut self.deserializer) .map(Some) .map_err(|e| e.into()) .transpose() } } pub struct ValuesIterator<R> where R: Read + Seek, { reader: DbfReader<R>, } impl<R: Read + Seek> Iterator for ValuesIterator<R> { type Item = Result<BTreeMap<String, Value>, Box<dyn std::error::Error>>; fn next(&mut self) -> Option<Self::Item> { let values = match self.reader.next_record() { Ok(Some(val)) => val, Ok(None) => return None, Err(e) => return Some(Err(e)), }; let key_iter = self.reader.fields().iter().map(|f| f.name.clone()); let val_iter = values.into_iter().map(From::from); Some(Ok(key_iter.zip(val_iter).collect())) } }