First iteration

src/writer.rs

@@ -0,0 +1,44 @@
+use anyhow::Result;
+use parquet::file::properties::WriterProperties;
+use parquet::schema::parser::parse_message_type;
+use parquet::record::RecordWriter;
+use std::fs::File;
+use std::sync::Arc;
+
+#[derive(parquet_derive::ParquetRecordWriter)]
+pub struct ScopeRecord {
+    pub timestamp: f64,
+    pub channel_1: f32,
+}
+
+pub struct ParquetWriter {
+    writer: parquet::file::writer::SerializedFileWriter<File>,
+}
+
+impl ParquetWriter {
+    pub fn new(path: &str) -> Result<Self> {
+        let file = File::create(path)?;
+        let schema = "
+            message schema {
+                REQUIRED DOUBLE timestamp;
+                REQUIRED FLOAT channel_1;
+            }
+        ";
+        let schema = Arc::new(parse_message_type(schema)?);
+        let props = Arc::new(WriterProperties::builder().build());
+        let writer = parquet::file::writer::SerializedFileWriter::new(file, schema, props)?;
+        Ok(Self { writer })
+    }
+
+    pub fn write_batch(&mut self, records: &[ScopeRecord]) -> Result<()> {
+        let mut row_group_writer = self.writer.next_row_group()?;
+        records.write_to_row_group(&mut row_group_writer)?;
+        row_group_writer.close()?;
+        Ok(())
+    }
+
+    pub fn close(self) -> Result<()> {
+        self.writer.close()?;
+        Ok(())
+    }
+}