+ async source

(reader and converter)

lib/src/questions.rs

@@ -69,7 +69,7 @@ pub struct Question {
     pub batch_info: BatchInfo,
 }
 
-#[cfg(feature = "source")]
+#[cfg(feature = "convert")]
 pub mod convert {
     use super::{BatchInfo, Question};
     use crate::source::{SourceQuestion, SourceQuestionsBatch};
@@ -138,6 +138,123 @@ pub mod convert {
         }
     }
 }
-
-#[cfg(feature = "source")]
+#[cfg(feature = "convert")]
 pub use convert::QuestionsConverter;
+
+#[cfg(feature = "convert_async")]
+pub mod convert_async {
+    use async_stream::stream;
+    use futures_core::stream::Stream;
+    use futures_core::Future;
+    use futures_util::{pin_mut, StreamExt};
+
+    use std::pin::Pin;
+    use std::task::{Context, Poll};
+
+    use super::{BatchInfo, Question};
+    use crate::source::{SourceQuestion, SourceQuestionsBatch};
+
+    macro_rules! make {
+        ($Target:ident; by {$($field:ident),+}; from $src:expr) => {$Target {$(
+            $field: $src.$field
+        ),+}};
+        ($Target:ident; with defaults and by {$($field:ident),+}; from $src:expr) => {$Target {$(
+            $field: $src.$field
+        ),+ ,..$Target::default()}}
+    }
+
+    impl From<SourceQuestion> for Question {
+        fn from(src: SourceQuestion) -> Self {
+            make! {Self; with defaults and by {
+                num, id, description, answer, author, comment, comment1, tour, url,
+                date, processed_by, redacted_by, copyright, theme, kind, source, rating
+            }; from src}
+        }
+    }
+
+    impl From<SourceQuestionsBatch> for BatchInfo {
+        fn from(src: SourceQuestionsBatch) -> Self {
+            make! {Self; by {
+                filename, description, author, comment, url, date,
+                processed_by, redacted_by, copyright, theme, kind, source, rating
+            }; from src}
+        }
+    }
+
+    impl From<SourceQuestionsBatch> for Vec<Question> {
+        fn from(src: SourceQuestionsBatch) -> Self {
+            let mut result: Vec<Question> = src
+                .questions
+                .iter()
+                .map(|item| item.clone().into())
+                .collect();
+            let batch_info = BatchInfo::from(src);
+            result.iter_mut().for_each(|question| {
+                question.batch_info = batch_info.clone();
+            });
+
+            result
+        }
+    }
+
+    pub struct QuestionsConverterAsync<T>
+    where
+        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
+            + std::marker::Unpin,
+    {
+        inner: T,
+    }
+
+    impl<T> From<T> for QuestionsConverterAsync<T>
+    where
+        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
+            + std::marker::Unpin,
+    {
+        fn from(inner: T) -> Self {
+            Self { inner }
+        }
+    }
+
+    impl<T> QuestionsConverterAsync<T>
+    where
+        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
+            + std::marker::Unpin,
+    {
+        fn convert(&mut self) -> impl Stream<Item = Question> + '_ {
+            stream! {
+                while let Some((filename, Ok(batch))) = self.inner.next().await {
+                    let mut batch = batch;
+                    batch.filename = filename;
+                    let questions: Vec<Question> = batch.into();
+                    for question in questions {
+                        yield question
+                    }
+                }
+            }
+        }
+    }
+
+    impl<T> Stream for QuestionsConverterAsync<T>
+    where
+        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
+            + std::marker::Unpin,
+    {
+        type Item = Question;
+
+        fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+            let convert = self.convert();
+            pin_mut!(convert);
+            match Pin::new(&mut convert.next()).poll(cx) {
+                Poll::Ready(Some(item)) => Poll::Ready(Some(item)),
+                Poll::Ready(None) => Poll::Ready(None),
+                Poll::Pending => Poll::Pending,
+            }
+        }
+
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            self.inner.size_hint()
+        }
+    }
+}
+#[cfg(feature = "convert_async")]
+pub use convert_async::QuestionsConverterAsync;