[feat] basic query builder for js; [feat] support chunked responses

Signed-off-by: Anton Nesterov <anton@demiurg.io>

dal/Builder.ts

@@ -1,5 +1,5 @@
 import type { Request } from "./Protocol";
-import { METHODS } from "./Protocol";
+import { METHODS, encodeRequest, decodeRowsIterator } from "./Protocol";
 
 type Primitive = string | number | boolean | null;
 
@@ -29,17 +29,23 @@ type JoinFilter = {
   $as?: JoinCondition;
 };
 
-export type SortOptions = Record<string, 1 | -1 | "asc" | "desc">;
+type SortOptions = Record<string, 1 | -1 | "asc" | "desc">;
 
+type Options = {
+    database: string;
+    url: string;
+};
 
 export default class Builder {
     private request: Request;
-    constructor(database: string) {
+    private url: string;
+    constructor(opts: Options) {
         this.request = {
             id: 0,
-            db: database,
+            db: opts.database,
             commands: [],
         };
+        this.url = opts.url;
     }
     private format(): void {
         this.request.commands = METHODS.map((method) => {
@@ -111,5 +117,27 @@ export default class Builder {
         this.request.commands.push({ method: "DoNothing", args: [] });
         return this;
     }
+    async *Rows() {
+        this.format();
+        const response = await fetch(this.url, {
+            method: "POST",
+            body: new Blob([encodeRequest(this.request)]),
+            headers: {
+                "Content-Type": "application/x-msgpack",
+            },
+        });
+        if (response.status !== 200) {
+            throw new Error(await response.text());
+        }
+
+        for await (const row of decodeRowsIterator(response.body!)) {
+            yield row;
+        }
+        this.request = {
+            id: 0,
+            db: this.request.db,
+            commands: [],
+        };
+    }
     
 }

dal/Protocol.ts

@@ -1,4 +1,4 @@
-import { encode } from '@msgpack/msgpack';
+import { encode, decode } from '@msgpack/msgpack';
 
 export interface Method {
     method: string;
@@ -15,4 +15,55 @@ export const METHODS = "In|Find|Select|Fields|Join|Group|Sort|Limit|Offset|Delet
 
 export function encodeRequest(request: Request): Uint8Array {
     return encode(request);
+}
+
+export interface Row {
+    r: unknown[];
+}
+
+const ROW_TAG = [0x81, 0xa1, 0x72];
+
+export function decodeRows(input: Uint8Array): Row[] {
+    const rows = [];
+    let count = 0;
+    let buf = [];
+    while (count < input.length) {
+        if (input.at(count) != 0x81) {
+			buf.push(input.at(count));
+			count++;
+			continue
+		}
+        const [a, b, c] = ROW_TAG;
+        const [aa, bb, cc] = input.slice(count, count + 4);
+        if (aa == a && bb == b && cc == c) {
+            rows.push([...ROW_TAG, ...buf]);
+            buf = [];
+            count += 3;
+        } else {
+            buf.push(input.at(count));
+            count++;
+        }
+    }
+    rows.push([...ROW_TAG, ...buf]);
+    rows.shift();
+    return rows.map((row) => decode(new Uint8Array(row as number[]))) as Row[];
+}
+
+export async function *decodeRowsIterator(stream: ReadableStream<Uint8Array>): AsyncGenerator<Row> {
+    const reader = stream.getReader();
+    let buf = new Uint8Array();
+    for (;;) {
+        const { value, done } = await reader.read();
+        if (done) {
+            console.log("done");
+            break;
+        }
+        buf = new Uint8Array([...buf, ...value]);
+        // the server flushes after each row
+        // so we decode "complete" rows
+        const rows = decodeRows(buf);
+        for (const row of rows) {
+            yield row;
+        }
+    }
 }

dal/__test__/protocol.test.ts

@@ -0,0 +1,24 @@
+import { test, expect } from "bun:test";
+import { DAL } from ".."
+
+const options = {
+    database: "test.sqlite",
+    url: "http://localhost:8111",
+}
+
+
+test("Rows iter",  async () => {
+    const dal = new DAL(options);
+    const rows = dal
+        .In("test t")
+        .Find({
+            id: 1,
+        })
+        .Rows();
+    for await (const row of rows) {
+        // console.log(row);
+        //@ts-ignore
+        expect(row.r.length).toBe(3);
+    }
+    expect(true).toBe(true);
+});

dal/__test__/srv/go.mod

@@ -0,0 +1,31 @@
+module srv
+
+go 1.22.6
+
+replace l12.xyz/dal/filters v0.0.0 => ../../../pkg/filters
+
+replace l12.xyz/dal/builder v0.0.0 => ../../../pkg/builder
+
+require l12.xyz/dal/adapter v0.0.0
+
+replace l12.xyz/dal/adapter v0.0.0 => ../../../pkg/adapter
+
+replace l12.xyz/dal/utils v0.0.0 => ../../../pkg/utils
+
+require l12.xyz/dal/proto v0.0.0 // indirect
+
+replace l12.xyz/dal/proto v0.0.0 => ../../../pkg/proto
+
+require l12.xyz/dal/server v0.0.0
+
+replace l12.xyz/dal/server v0.0.0 => ../../../pkg/server
+
+require (
+	github.com/mattn/go-sqlite3 v1.14.22
+	github.com/philhofer/fwd v1.1.3-0.20240612014219-fbbf4953d986 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/tinylib/msgp v1.2.0 // indirect
+	l12.xyz/dal/builder v0.0.0 // indirect
+	l12.xyz/dal/filters v0.0.0 // indirect
+	l12.xyz/dal/utils v0.0.0 // indirect
+)

dal/__test__/srv/go.sum

@@ -0,0 +1,8 @@
+github.com/mattn/go-sqlite3 v1.14.22 h1:2gZY6PC6kBnID23Tichd1K+Z0oS6nE/XwU+Vz/5o4kU=
+github.com/mattn/go-sqlite3 v1.14.22/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
+github.com/philhofer/fwd v1.1.3-0.20240612014219-fbbf4953d986 h1:jYi87L8j62qkXzaYHAQAhEapgukhenIMZRBKTNRLHJ4=
+github.com/philhofer/fwd v1.1.3-0.20240612014219-fbbf4953d986/go.mod h1:RqIHx9QI14HlwKwm98g9Re5prTQ6LdeRQn+gXJFxsJM=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/tinylib/msgp v1.2.0 h1:0uKB/662twsVBpYUPbokj4sTSKhWFKB7LopO2kWK8lY=
+github.com/tinylib/msgp v1.2.0/go.mod h1:2vIGs3lcUo8izAATNobrCHevYZC/LMsJtw4JPiYPHro=

dal/__test__/srv/main.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+
+	_ "github.com/mattn/go-sqlite3"
+	"l12.xyz/dal/adapter"
+	"l12.xyz/dal/server"
+)
+
+func mock(adapter adapter.DBAdapter) {
+	db, _ := adapter.Open("test.sqlite")
+	defer db.Close()
+	db.Exec("CREATE TABLE IF NOT EXISTS test (id INTEGER PRIMARY KEY, name BLOB, data TEXT)")
+	db.Exec("INSERT INTO test (name, data) VALUES (?,?)", "test", "y")
+	db.Exec("INSERT INTO test (name, data) VALUES (?,?)", "tost", "x")
+	db.Exec("INSERT INTO test (name, data) VALUES (?,?)", "foo", "a")
+	db.Exec("INSERT INTO test (name, data) VALUES (?,?)", "bar", "b")
+}
+
+func main() {
+	db := adapter.DBAdapter{
+		Type: "sqlite3",
+	}
+	mock(db)
+	queryHandler := server.QueryHandler(db)
+	mux := http.NewServeMux()
+	mux.Handle("/", queryHandler)
+	fmt.Println("Server running on port 8111")
+	http.ListenAndServe(":8111", mux)
+}

dal/index.ts

@@ -0,0 +1 @@
+export { default as DAL } from './Builder';

package.json

@@ -10,5 +10,10 @@
   },
   "dependencies": {
     "@msgpack/msgpack": "^3.0.0-beta2"
+  },
+  "scripts": {
+    "test:client": "bun test:*",
+    "test:dal" : "bun test dal/__test__",
+    "test:serve": "cd dal/__test__/srv && go run main.go"
   }
 }

pkg/server/query_handler.go

@@ -22,13 +22,7 @@ func QueryHandler(db adapter.DBAdapter) http.Handler {
 	dialect := adapter.GetDialect(db.Type)
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 
-		bodyReader, err := r.GetBody()
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-
-		body, err := io.ReadAll(bodyReader)
+		body, err := io.ReadAll(r.Body)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
@@ -50,12 +44,18 @@ func QueryHandler(db adapter.DBAdapter) http.Handler {
 		}
 		defer rows.Close()
 
+		w.Header().Set("X-Content-Type-Options", "nosniff")
 		w.Header().Set("Content-Type", "application/x-msgpack")
-
+		flusher, ok := w.(http.Flusher)
+		if !ok {
+			http.Error(w, "expected http.ResponseWriter to be an http.Flusher", http.StatusInternalServerError)
+			return
+		}
 		columns, _ := rows.Columns()
 		types, _ := rows.ColumnTypes()
 		cols, _ := proto.MarshalRow(columns)
 		w.Write(cols)
+		flusher.Flush()
 
 		for rows.Next() {
 			data := make([]interface{}, len(columns))
@@ -66,6 +66,7 @@ func QueryHandler(db adapter.DBAdapter) http.Handler {
 			rows.Scan(data...)
 			cols, _ := proto.MarshalRow(data)
 			w.Write(cols)
+			flusher.Flush()
 		}
 	})
 }

pkg/server/query_handler_test.go

@@ -33,7 +33,7 @@ func TestQueryHandler(t *testing.T) {
 	data := proto.Request{
 		Id: 0,
 		Db: "file::memory:?cache=shared",
-		Commands: []proto.BuildCmd{
+		Commands: []proto.BuilderMethod{
 			{Method: "In", Args: []interface{}{"test t"}},
 			{Method: "Find", Args: []interface{}{
 				map[string]interface{}{"id": 1},