feat(nodejs): protocol version option, binary protocol for doubles (#49)

Author: glasstiger

src/buffer/base.ts

@@ -0,0 +1,38 @@
+// @ts-check
+import { SenderOptions } from "../options";
+import { SenderBuffer } from "./index";
+import { SenderBufferBase } from "./base";
+
+/**
+ * Buffer implementation for protocol version 1.
+ * Sends floating point numbers in their text form.
+ */
+class SenderBufferV1 extends SenderBufferBase {
+  constructor(options: SenderOptions) {
+    super(options);
+  }
+
+  /**
+   * Writes a 64-bit floating point value into the buffer using v1 serialization (text format). <br>
+   * Use it to insert into DOUBLE or FLOAT database columns.
+   *
+   * @param {string} name - Column name.
+   * @param {number} value - Column value, accepts only number values.
+   * @return {Sender} Returns with a reference to this sender.
+   */
+  floatColumn(name: string, value: number): SenderBuffer {
+    this.writeColumn(
+      name,
+      value,
+      () => {
+        const valueStr = value.toString();
+        this.checkCapacity([valueStr]);
+        this.write(valueStr);
+      },
+      "number",
+    );
+    return this;
+  }
+}
+
+export { SenderBufferV1 };

src/buffer/bufferv1.ts

@@ -0,0 +1,42 @@
+// @ts-check
+import { SenderOptions } from "../options";
+import { SenderBuffer } from "./index";
+import { SenderBufferBase } from "./base";
+
+const ENTITY_TYPE_DOUBLE: number = 16;
+const EQUALS_SIGN: number = "=".charCodeAt(0);
+
+/**
+ * Buffer implementation for protocol version 2.
+ * Sends floating point numbers in binary form.
+ */
+class SenderBufferV2 extends SenderBufferBase {
+  constructor(options: SenderOptions) {
+    super(options);
+  }
+
+  /**
+   * Writes a 64-bit floating point value into the buffer using v2 serialization (binary format). <br>
+   * Use it to insert into DOUBLE or FLOAT database columns.
+   *
+   * @param {string} name - Column name.
+   * @param {number} value - Column value, accepts only number values.
+   * @return {Sender} Returns with a reference to this sender.
+   */
+  floatColumn(name: string, value: number): SenderBuffer {
+    this.writeColumn(
+      name,
+      value,
+      () => {
+        this.checkCapacity([], 10);
+        this.writeByte(EQUALS_SIGN);
+        this.writeByte(ENTITY_TYPE_DOUBLE);
+        this.writeDouble(value);
+      },
+      "number",
+    );
+    return this;
+  }
+}
+
+export { SenderBufferV2 };