feat: add json format output for http interface

src/servers/src/http.rs

@@ -59,6 +59,7 @@ use crate::http::error_result::ErrorResponse;
 use crate::http::greptime_result_v1::GreptimedbV1Response;
 use crate::http::influxdb::{influxdb_health, influxdb_ping, influxdb_write_v1, influxdb_write_v2};
 use crate::http::influxdb_result_v1::InfluxdbV1Response;
+use crate::http::json_result::JsonResponse;
 use crate::http::prometheus::{
     build_info_query, format_query, instant_query, label_values_query, labels_query, range_query,
     series_query,
@@ -97,6 +98,7 @@ pub mod error_result;
 pub mod greptime_manage_resp;
 pub mod greptime_result_v1;
 pub mod influxdb_result_v1;
+pub mod json_result;
 pub mod table_result;
 
 #[cfg(any(test, feature = "testing"))]
@@ -279,6 +281,7 @@ pub enum ResponseFormat {
     #[default]
     GreptimedbV1,
     InfluxdbV1,
+    Json,
 }
 
 impl ResponseFormat {
@@ -289,6 +292,7 @@ impl ResponseFormat {
             "table" => Some(ResponseFormat::Table),
             "greptimedb_v1" => Some(ResponseFormat::GreptimedbV1),
             "influxdb_v1" => Some(ResponseFormat::InfluxdbV1),
+            "json" => Some(ResponseFormat::Json),
             _ => None,
         }
     }
@@ -300,6 +304,7 @@ impl ResponseFormat {
             ResponseFormat::Table => "table",
             ResponseFormat::GreptimedbV1 => "greptimedb_v1",
             ResponseFormat::InfluxdbV1 => "influxdb_v1",
+            ResponseFormat::Json => "json",
         }
     }
 }
@@ -356,6 +361,7 @@ pub enum HttpResponse {
     Error(ErrorResponse),
     GreptimedbV1(GreptimedbV1Response),
     InfluxdbV1(InfluxdbV1Response),
+    Json(JsonResponse),
 }
 
 impl HttpResponse {
@@ -366,6 +372,7 @@ impl HttpResponse {
             HttpResponse::Table(resp) => resp.with_execution_time(execution_time).into(),
             HttpResponse::GreptimedbV1(resp) => resp.with_execution_time(execution_time).into(),
             HttpResponse::InfluxdbV1(resp) => resp.with_execution_time(execution_time).into(),
+            HttpResponse::Json(resp) => resp.with_execution_time(execution_time).into(),
             HttpResponse::Error(resp) => resp.with_execution_time(execution_time).into(),
         }
     }
@@ -375,6 +382,7 @@ impl HttpResponse {
             HttpResponse::Csv(resp) => resp.with_limit(limit).into(),
             HttpResponse::Table(resp) => resp.with_limit(limit).into(),
             HttpResponse::GreptimedbV1(resp) => resp.with_limit(limit).into(),
+            HttpResponse::Json(resp) => resp.with_limit(limit).into(),
             _ => self,
         }
     }
@@ -407,6 +415,7 @@ impl IntoResponse for HttpResponse {
             HttpResponse::Table(resp) => resp.into_response(),
             HttpResponse::GreptimedbV1(resp) => resp.into_response(),
             HttpResponse::InfluxdbV1(resp) => resp.into_response(),
+            HttpResponse::Json(resp) => resp.into_response(),
             HttpResponse::Error(resp) => resp.into_response(),
         }
     }
@@ -452,6 +461,12 @@ impl From<InfluxdbV1Response> for HttpResponse {
     }
 }
 
+impl From<JsonResponse> for HttpResponse {
+    fn from(value: JsonResponse) -> Self {
+        HttpResponse::Json(value)
+    }
+}
+
 async fn serve_api(Extension(api): Extension<OpenApi>) -> impl IntoApiResponse {
     Json(api)
 }
@@ -1131,6 +1146,7 @@ mod test {
             ResponseFormat::Csv,
             ResponseFormat::Table,
             ResponseFormat::Arrow,
+            ResponseFormat::Json,
         ] {
             let recordbatches =
                 RecordBatches::try_new(schema.clone(), vec![recordbatch.clone()]).unwrap();
@@ -1141,6 +1157,7 @@ mod test {
                 ResponseFormat::Table => TableResponse::from_output(outputs).await,
                 ResponseFormat::GreptimedbV1 => GreptimedbV1Response::from_output(outputs).await,
                 ResponseFormat::InfluxdbV1 => InfluxdbV1Response::from_output(outputs, None).await,
+                ResponseFormat::Json => JsonResponse::from_output(outputs).await,
             };
 
             match json_resp {
@@ -1210,6 +1227,21 @@ mod test {
                     assert_eq!(rb.num_columns(), 2);
                     assert_eq!(rb.num_rows(), 4);
                 }
+
+                HttpResponse::Json(resp) => {
+                    let output = &resp.output()[0];
+                    if let GreptimeQueryOutput::Records(r) = output {
+                        assert_eq!(r.num_rows(), 4);
+                        assert_eq!(r.num_cols(), 2);
+                        assert_eq!(r.schema.column_schemas[0].name, "numbers");
+                        assert_eq!(r.schema.column_schemas[0].data_type, "UInt32");
+                        assert_eq!(r.rows[0][0], serde_json::Value::from(1));
+                        assert_eq!(r.rows[0][1], serde_json::Value::Null);
+                    } else {
+                        panic!("invalid output type");
+                    }
+                }
+
                 HttpResponse::Error(err) => unreachable!("{err:?}"),
             }
         }

src/servers/src/http/handler.rs

@@ -39,6 +39,7 @@ use crate::http::csv_result::CsvResponse;
 use crate::http::error_result::ErrorResponse;
 use crate::http::greptime_result_v1::GreptimedbV1Response;
 use crate::http::influxdb_result_v1::InfluxdbV1Response;
+use crate::http::json_result::JsonResponse;
 use crate::http::table_result::TableResponse;
 use crate::http::{
     ApiState, Epoch, GreptimeOptionsConfigState, GreptimeQueryOutput, HttpRecordsOutput,
@@ -138,6 +139,7 @@ pub async fn sql(
         ResponseFormat::Table => TableResponse::from_output(outputs).await,
         ResponseFormat::GreptimedbV1 => GreptimedbV1Response::from_output(outputs).await,
         ResponseFormat::InfluxdbV1 => InfluxdbV1Response::from_output(outputs, epoch).await,
+        ResponseFormat::Json => JsonResponse::from_output(outputs).await,
     };
 
     if let Some(limit) = query_params.limit {

src/servers/src/http/json_result.rs

@@ -0,0 +1,137 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use axum::http::{header, HeaderValue};
+use axum::response::{IntoResponse, Response};
+use common_error::status_code::StatusCode;
+use common_query::Output;
+use mime_guess::mime;
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+use serde_json::{json, Map, Value};
+
+use super::process_with_limit;
+use crate::http::error_result::ErrorResponse;
+use crate::http::header::{GREPTIME_DB_HEADER_EXECUTION_TIME, GREPTIME_DB_HEADER_FORMAT};
+use crate::http::{handler, GreptimeQueryOutput, HttpResponse, ResponseFormat};
+
+/// The json format here is different from the default json output of `GreptimedbV1` result.
+/// `JsonResponse` is intended to make it easier for user to consume data.
+#[derive(Serialize, Deserialize, Debug, JsonSchema)]
+pub struct JsonResponse {
+    output: Vec<GreptimeQueryOutput>,
+    execution_time_ms: u64,
+}
+
+impl JsonResponse {
+    pub async fn from_output(outputs: Vec<crate::error::Result<Output>>) -> HttpResponse {
+        match handler::from_output(outputs).await {
+            Err(err) => HttpResponse::Error(err),
+            Ok((output, _)) => {
+                if output.len() > 1 {
+                    HttpResponse::Error(ErrorResponse::from_error_message(
+                        StatusCode::InvalidArguments,
+                        "cannot output multi-statements result in json format".to_string(),
+                    ))
+                } else {
+                    HttpResponse::Json(JsonResponse {
+                        output,
+                        execution_time_ms: 0,
+                    })
+                }
+            }
+        }
+    }
+
+    pub fn output(&self) -> &[GreptimeQueryOutput] {
+        &self.output
+    }
+
+    pub fn with_execution_time(mut self, execution_time: u64) -> Self {
+        self.execution_time_ms = execution_time;
+        self
+    }
+
+    pub fn execution_time_ms(&self) -> u64 {
+        self.execution_time_ms
+    }
+
+    pub fn with_limit(mut self, limit: usize) -> Self {
+        self.output = process_with_limit(self.output, limit);
+        self
+    }
+}
+
+impl IntoResponse for JsonResponse {
+    fn into_response(mut self) -> Response {
+        debug_assert!(
+            self.output.len() <= 1,
+            "self.output has extra elements: {}",
+            self.output.len()
+        );
+
+        let execution_time = self.execution_time_ms;
+        let payload = match self.output.pop() {
+            None => String::default(),
+            Some(GreptimeQueryOutput::AffectedRows(n)) => json!({
+                "data": [],
+                "affected_rows": n,
+                "execution_time_ms": execution_time,
+            })
+            .to_string(),
+
+            Some(GreptimeQueryOutput::Records(records)) => {
+                let schema = records.schema();
+
+                let data: Vec<Map<String, Value>> = records
+                    .rows
+                    .iter()
+                    .map(|row| {
+                        schema
+                            .column_schemas
+                            .iter()
+                            .enumerate()
+                            .map(|(i, col)| (col.name.clone(), row[i].clone()))
+                            .collect::<Map<String, Value>>()
+                    })
+                    .collect();
+
+                json!({
+                    "data": data,
+                    "execution_time_ms": execution_time,
+                })
+                .to_string()
+            }
+        };
+
+        (
+            [
+                (
+                    header::CONTENT_TYPE,
+                    HeaderValue::from_static(mime::APPLICATION_JSON.as_ref()),
+                ),
+                (
+                    GREPTIME_DB_HEADER_FORMAT.clone(),
+                    HeaderValue::from_static(ResponseFormat::Json.as_str()),
+                ),
+                (
+                    GREPTIME_DB_HEADER_EXECUTION_TIME.clone(),
+                    HeaderValue::from(execution_time),
+                ),
+            ],
+            payload,
+        )
+            .into_response()
+    }
+}

tests-integration/tests/http.rs

@@ -181,6 +181,22 @@ pub async fn test_sql_api(store_type: StorageType) {
         })).unwrap()
     );
 
+    // test json result format
+    let res = client
+        .get("/v1/sql?format=json&sql=select * from numbers limit 10")
+        .send()
+        .await;
+    assert_eq!(res.status(), StatusCode::OK);
+
+    let body = res.json::<Value>().await;
+    let data = body.get("data").expect("Missing 'data' field in response");
+
+    let expected = json!([
+        {"number": 0}, {"number": 1}, {"number": 2}, {"number": 3}, {"number": 4},
+        {"number": 5}, {"number": 6}, {"number": 7}, {"number": 8}, {"number": 9}
+    ]);
+    assert_eq!(data, &expected);
+
     // test insert and select
     let res = client
         .get("/v1/sql?sql=insert into demo values('host', 66.6, 1024, 0)")
@@ -1236,7 +1252,7 @@ transform:
         .send()
         .await;
     assert_eq!(res.status(), StatusCode::OK);
-    let body: serde_json::Value = res.json().await;
+    let body: Value = res.json().await;
     let schema = &body["schema"];
     let rows = &body["rows"];
     assert_eq!(