Split up HTTP sending logic (#320)

src-tauri/yaak-http/src/chained_reader.rs

@@ -0,0 +1,78 @@
+use std::io;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use tokio::io::{AsyncRead, ReadBuf};
+
+/// A stream that chains multiple AsyncRead sources together
+pub(crate) struct ChainedReader {
+    readers: Vec<ReaderType>,
+    current_index: usize,
+    current_reader: Option<Box<dyn AsyncRead + Send + Unpin + 'static>>,
+}
+
+#[derive(Clone)]
+pub(crate) enum ReaderType {
+    Bytes(Vec<u8>),
+    FilePath(String),
+}
+
+impl ChainedReader {
+    pub(crate) fn new(readers: Vec<ReaderType>) -> Self {
+        Self { readers, current_index: 0, current_reader: None }
+    }
+}
+
+impl AsyncRead for ChainedReader {
+    fn poll_read(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
+        loop {
+            // Try to read from current reader if we have one
+            if let Some(ref mut reader) = self.current_reader {
+                let before_len = buf.filled().len();
+                return match Pin::new(reader).poll_read(cx, buf) {
+                    Poll::Ready(Ok(())) => {
+                        if buf.filled().len() == before_len && buf.remaining() > 0 {
+                            // Current reader is exhausted, move to next
+                            self.current_reader = None;
+                            continue;
+                        }
+                        Poll::Ready(Ok(()))
+                    }
+                    Poll::Ready(Err(e)) => Poll::Ready(Err(e)),
+                    Poll::Pending => Poll::Pending,
+                };
+            }
+
+            // We need to get the next reader
+            if self.current_index >= self.readers.len() {
+                // No more readers
+                return Poll::Ready(Ok(()));
+            }
+
+            // Get the next reader
+            let reader_type = self.readers[self.current_index].clone();
+            self.current_index += 1;
+
+            match reader_type {
+                ReaderType::Bytes(bytes) => {
+                    self.current_reader = Some(Box::new(io::Cursor::new(bytes)));
+                }
+                ReaderType::FilePath(path) => {
+                    // We need to handle file opening synchronously in poll_read
+                    // This is a limitation - we'll use blocking file open
+                    match std::fs::File::open(&path) {
+                        Ok(file) => {
+                            // Convert std File to tokio File
+                            let tokio_file = tokio::fs::File::from_std(file);
+                            self.current_reader = Some(Box::new(tokio_file));
+                        }
+                        Err(e) => return Poll::Ready(Err(e)),
+                    }
+                }
+            }
+        }
+    }
+}