move csv parsing to document_formats

meilisearch-lib/src/document_formats.rs

@@ -1,8 +1,7 @@
-use std::{
-    fmt,
-    io::{Read, Seek, Write},
-};
+use std::io::{self, Read, Result as IoResult, Seek, Write};
+use std::fmt;
 
+use csv::{Reader as CsvReader, StringRecordsIntoIter};
 use milli::documents::DocumentBatchBuilder;
 use serde_json::{Deserializer, Map, Value};
 
@@ -12,6 +11,7 @@ type Result<T> = std::result::Result<T, DocumentFormatError>;
 pub enum PayloadType {
     Jsonl,
     Json,
+    Csv,
 }
 
 impl fmt::Display for PayloadType {
@@ -19,6 +19,7 @@ impl fmt::Display for PayloadType {
         match self {
             PayloadType::Jsonl => write!(f, "ndjson"),
             PayloadType::Json => write!(f, "json"),
+            PayloadType::Csv => write!(f, "csv"),
         }
     }
 }
@@ -34,7 +35,7 @@ pub enum DocumentFormatError {
     ),
 }
 
-internal_error!(DocumentFormatError: milli::documents::Error);
+internal_error!(DocumentFormatError: milli::documents::Error, io::Error);
 
 macro_rules! malformed {
     ($type:path, $e:expr) => {
@@ -42,6 +43,20 @@ macro_rules! malformed {
     };
 }
 
+pub fn read_csv(input: impl Read, writer: impl Write + Seek) -> Result<()> {
+    let mut builder = DocumentBatchBuilder::new(writer).unwrap();
+
+    let iter = CsvDocumentIter::from_reader(input)?;
+    for doc in iter {
+        let doc = doc?;
+        builder.add_documents(doc).unwrap();
+    }
+    builder.finish().unwrap();
+
+    Ok(())
+}
+
+
 /// read jsonl from input and write an obkv batch to writer.
 pub fn read_jsonl(input: impl Read, writer: impl Write + Seek) -> Result<()> {
     let mut builder = DocumentBatchBuilder::new(writer)?;
@@ -68,3 +83,281 @@ pub fn read_json(input: impl Read, writer: impl Write + Seek) -> Result<()> {
 
     Ok(())
 }
+
+
+enum AllowedType {
+    String,
+    Number,
+}
+
+fn parse_csv_header(header: &str) -> (String, AllowedType) {
+    // if there are several separators we only split on the last one.
+    match header.rsplit_once(':') {
+        Some((field_name, field_type)) => match field_type {
+            "string" => (field_name.to_string(), AllowedType::String),
+            "number" => (field_name.to_string(), AllowedType::Number),
+            // if the pattern isn't reconized, we keep the whole field.
+            _otherwise => (header.to_string(), AllowedType::String),
+        },
+        None => (header.to_string(), AllowedType::String),
+    }
+}
+
+pub struct CsvDocumentIter<R>
+where
+    R: Read,
+{
+    documents: StringRecordsIntoIter<R>,
+    headers: Vec<(String, AllowedType)>,
+}
+
+impl<R: Read> CsvDocumentIter<R> {
+    pub fn from_reader(reader: R) -> IoResult<Self> {
+        let mut records = CsvReader::from_reader(reader);
+
+        let headers = records
+            .headers()?
+            .into_iter()
+            .map(parse_csv_header)
+            .collect();
+
+        Ok(Self {
+            documents: records.into_records(),
+            headers,
+        })
+    }
+}
+
+impl<R: Read> Iterator for CsvDocumentIter<R> {
+    type Item = Result<Map<String, Value>>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let csv_document = self.documents.next()?;
+
+        match csv_document {
+            Ok(csv_document) => {
+                let mut document = Map::new();
+
+                for ((field_name, field_type), value) in
+                    self.headers.iter().zip(csv_document.into_iter())
+                {
+                    let parsed_value = (|| match field_type {
+                        AllowedType::Number => malformed!(PayloadType::Csv, value
+                            .parse::<f64>()
+                            .map(Value::from)),
+                        AllowedType::String => Ok(Value::String(value.to_string())),
+                    })();
+
+                    match parsed_value {
+                        Ok(value) => drop(document.insert(field_name.to_string(), value)),
+                        Err(e) => return Some(Err(e)),
+                    }
+                }
+
+                Some(Ok(document))
+            }
+            Err(e) => Some(Err(DocumentFormatError::MalformedPayload(Box::new(e), PayloadType::Csv))),
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use serde_json::json;
+
+    use super::*;
+
+    #[test]
+    fn simple_csv_document() {
+        let documents = r#"city,country,pop
+"Boston","United States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert_eq!(
+            Value::Object(csv_iter.next().unwrap().unwrap()),
+            json!({
+                "city": "Boston",
+                "country": "United States",
+                "pop": "4628910",
+            })
+        );
+    }
+
+    #[test]
+    fn coma_in_field() {
+        let documents = r#"city,country,pop
+"Boston","United, States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert_eq!(
+            Value::Object(csv_iter.next().unwrap().unwrap()),
+            json!({
+                "city": "Boston",
+                "country": "United, States",
+                "pop": "4628910",
+            })
+        );
+    }
+
+    #[test]
+    fn quote_in_field() {
+        let documents = r#"city,country,pop
+"Boston","United"" States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert_eq!(
+            Value::Object(csv_iter.next().unwrap().unwrap()),
+            json!({
+                "city": "Boston",
+                "country": "United\" States",
+                "pop": "4628910",
+            })
+        );
+    }
+
+    #[test]
+    fn integer_in_field() {
+        let documents = r#"city,country,pop:number
+"Boston","United States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert_eq!(
+            Value::Object(csv_iter.next().unwrap().unwrap()),
+            json!({
+                "city": "Boston",
+                "country": "United States",
+                "pop": 4628910.0,
+            })
+        );
+    }
+
+    #[test]
+    fn float_in_field() {
+        let documents = r#"city,country,pop:number
+"Boston","United States","4628910.01""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert_eq!(
+            Value::Object(csv_iter.next().unwrap().unwrap()),
+            json!({
+                "city": "Boston",
+                "country": "United States",
+                "pop": 4628910.01,
+            })
+        );
+    }
+
+    #[test]
+    fn several_colon_in_header() {
+        let documents = r#"city:love:string,country:state,pop
+"Boston","United States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert_eq!(
+            Value::Object(csv_iter.next().unwrap().unwrap()),
+            json!({
+                "city:love": "Boston",
+                "country:state": "United States",
+                "pop": "4628910",
+            })
+        );
+    }
+
+    #[test]
+    fn ending_by_colon_in_header() {
+        let documents = r#"city:,country,pop
+"Boston","United States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert_eq!(
+            Value::Object(csv_iter.next().unwrap().unwrap()),
+            json!({
+                "city:": "Boston",
+                "country": "United States",
+                "pop": "4628910",
+            })
+        );
+    }
+
+    #[test]
+    fn starting_by_colon_in_header() {
+        let documents = r#":city,country,pop
+"Boston","United States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert_eq!(
+            Value::Object(csv_iter.next().unwrap().unwrap()),
+            json!({
+                ":city": "Boston",
+                "country": "United States",
+                "pop": "4628910",
+            })
+        );
+    }
+
+    #[ignore]
+    #[test]
+    fn starting_by_colon_in_header2() {
+        let documents = r#":string,country,pop
+"Boston","United States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert!(dbg!(csv_iter.next().unwrap()).is_err());
+    }
+
+    #[test]
+    fn double_colon_in_header() {
+        let documents = r#"city::string,country,pop
+"Boston","United States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert_eq!(
+            Value::Object(csv_iter.next().unwrap().unwrap()),
+            json!({
+                "city:": "Boston",
+                "country": "United States",
+                "pop": "4628910",
+            })
+        );
+    }
+
+    #[test]
+    fn bad_type_in_header() {
+        let documents = r#"city,country:number,pop
+"Boston","United States","4628910""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert!(csv_iter.next().unwrap().is_err());
+    }
+
+    #[test]
+    fn bad_column_count1() {
+        let documents = r#"city,country,pop
+"Boston","United States","4628910", "too much""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert!(csv_iter.next().unwrap().is_err());
+    }
+
+    #[test]
+    fn bad_column_count2() {
+        let documents = r#"city,country,pop
+"Boston","United States""#;
+
+        let mut csv_iter = CsvDocumentIter::from_reader(documents.as_bytes()).unwrap();
+
+        assert!(csv_iter.next().unwrap().is_err());
+    }
+}