Started to implement server

2023-06-11 15:43:45 -04:00
1 parent 1f2ea8b7e5
commit 17a1b4bed3
@@ -0,0 +1,222 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { copy } from "../bytes/copy.ts";
+import type { Writer, WriterSync } from "../types.d.ts";
+
+const DEFAULT_BUF_SIZE = 4096;
+
+abstract class AbstractBufBase {
+  buf: Uint8Array;
+  usedBufferBytes = 0;
+  err: Error | null = null;
+
+  constructor(buf: Uint8Array) {
+    this.buf = buf;
+  }
+
+  /** Size returns the size of the underlying buffer in bytes. */
+  size(): number {
+    return this.buf.byteLength;
+  }
+
+  /** Returns how many bytes are unused in the buffer. */
+  available(): number {
+    return this.buf.byteLength - this.usedBufferBytes;
+  }
+
+  /** buffered returns the number of bytes that have been written into the
+   * current buffer.
+   */
+  buffered(): number {
+    return this.usedBufferBytes;
+  }
+}
+
+/** BufWriter implements buffering for an deno.Writer object.
+ * If an error occurs writing to a Writer, no more data will be
+ * accepted and all subsequent writes, and flush(), will return the error.
+ * After all data has been written, the client should call the
+ * flush() method to guarantee all data has been forwarded to
+ * the underlying deno.Writer.
+ */
+export class BufWriter extends AbstractBufBase implements Writer {
+  #writer: Writer;
+
+  /** return new BufWriter unless writer is BufWriter */
+  static create(writer: Writer, size: number = DEFAULT_BUF_SIZE): BufWriter {
+    return writer instanceof BufWriter ? writer : new BufWriter(writer, size);
+  }
+
+  constructor(writer: Writer, size: number = DEFAULT_BUF_SIZE) {
+    super(new Uint8Array(size <= 0 ? DEFAULT_BUF_SIZE : size));
+    this.#writer = writer;
+  }
+
+  /** Discards any unflushed buffered data, clears any error, and
+   * resets buffer to write its output to w.
+   */
+  reset(w: Writer) {
+    this.err = null;
+    this.usedBufferBytes = 0;
+    this.#writer = w;
+  }
+
+  /** Flush writes any buffered data to the underlying io.Writer. */
+  async flush() {
+    if (this.err !== null) throw this.err;
+    if (this.usedBufferBytes === 0) return;
+
+    try {
+      const p = this.buf.subarray(0, this.usedBufferBytes);
+      let nwritten = 0;
+      while (nwritten < p.length) {
+        nwritten += await this.#writer.write(p.subarray(nwritten));
+      }
+    } catch (e) {
+      if (e instanceof Error) {
+        this.err = e;
+      }
+      throw e;
+    }
+
+    this.buf = new Uint8Array(this.buf.length);
+    this.usedBufferBytes = 0;
+  }
+
+  /** Writes the contents of `data` into the buffer. If the contents won't fully
+   * fit into the buffer, those bytes that are copied into the buffer will be flushed
+   * to the writer and the remaining bytes are then copied into the now empty buffer.
+   *
+   * @return the number of bytes written to the buffer.
+   */
+  async write(data: Uint8Array): Promise<number> {
+    if (this.err !== null) throw this.err;
+    if (data.length === 0) return 0;
+
+    let totalBytesWritten = 0;
+    let numBytesWritten = 0;
+    while (data.byteLength > this.available()) {
+      if (this.buffered() === 0) {
+        // Large write, empty buffer.
+        // Write directly from data to avoid copy.
+        try {
+          numBytesWritten = await this.#writer.write(data);
+        } catch (e) {
+          if (e instanceof Error) {
+            this.err = e;
+          }
+          throw e;
+        }
+      } else {
+        numBytesWritten = copy(data, this.buf, this.usedBufferBytes);
+        this.usedBufferBytes += numBytesWritten;
+        await this.flush();
+      }
+      totalBytesWritten += numBytesWritten;
+      data = data.subarray(numBytesWritten);
+    }
+
+    numBytesWritten = copy(data, this.buf, this.usedBufferBytes);
+    this.usedBufferBytes += numBytesWritten;
+    totalBytesWritten += numBytesWritten;
+    return totalBytesWritten;
+  }
+}
+
+/** BufWriterSync implements buffering for a deno.WriterSync object.
+ * If an error occurs writing to a WriterSync, no more data will be
+ * accepted and all subsequent writes, and flush(), will return the error.
+ * After all data has been written, the client should call the
+ * flush() method to guarantee all data has been forwarded to
+ * the underlying deno.WriterSync.
+ */
+export class BufWriterSync extends AbstractBufBase implements WriterSync {
+  #writer: WriterSync;
+
+  /** return new BufWriterSync unless writer is BufWriterSync */
+  static create(
+    writer: WriterSync,
+    size: number = DEFAULT_BUF_SIZE,
+  ): BufWriterSync {
+    return writer instanceof BufWriterSync
+      ? writer
+      : new BufWriterSync(writer, size);
+  }
+
+  constructor(writer: WriterSync, size: number = DEFAULT_BUF_SIZE) {
+    super(new Uint8Array(size <= 0 ? DEFAULT_BUF_SIZE : size));
+    this.#writer = writer;
+  }
+
+  /** Discards any unflushed buffered data, clears any error, and
+   * resets buffer to write its output to w.
+   */
+  reset(w: WriterSync) {
+    this.err = null;
+    this.usedBufferBytes = 0;
+    this.#writer = w;
+  }
+
+  /** Flush writes any buffered data to the underlying io.WriterSync. */
+  flush() {
+    if (this.err !== null) throw this.err;
+    if (this.usedBufferBytes === 0) return;
+
+    try {
+      const p = this.buf.subarray(0, this.usedBufferBytes);
+      let nwritten = 0;
+      while (nwritten < p.length) {
+        nwritten += this.#writer.writeSync(p.subarray(nwritten));
+      }
+    } catch (e) {
+      if (e instanceof Error) {
+        this.err = e;
+      }
+      throw e;
+    }
+
+    this.buf = new Uint8Array(this.buf.length);
+    this.usedBufferBytes = 0;
+  }
+
+  /** Writes the contents of `data` into the buffer.  If the contents won't fully
+   * fit into the buffer, those bytes that can are copied into the buffer, the
+   * buffer is the flushed to the writer and the remaining bytes are copied into
+   * the now empty buffer.
+   *
+   * @return the number of bytes written to the buffer.
+   */
+  writeSync(data: Uint8Array): number {
+    if (this.err !== null) throw this.err;
+    if (data.length === 0) return 0;
+
+    let totalBytesWritten = 0;
+    let numBytesWritten = 0;
+    while (data.byteLength > this.available()) {
+      if (this.buffered() === 0) {
+        // Large write, empty buffer.
+        // Write directly from data to avoid copy.
+        try {
+          numBytesWritten = this.#writer.writeSync(data);
+        } catch (e) {
+          if (e instanceof Error) {
+            this.err = e;
+          }
+          throw e;
+        }
+      } else {
+        numBytesWritten = copy(data, this.buf, this.usedBufferBytes);
+        this.usedBufferBytes += numBytesWritten;
+        this.flush();
+      }
+      totalBytesWritten += numBytesWritten;
+      data = data.subarray(numBytesWritten);
+    }
+
+    numBytesWritten = copy(data, this.buf, this.usedBufferBytes);
+    this.usedBufferBytes += numBytesWritten;
+    totalBytesWritten += numBytesWritten;
+    return totalBytesWritten;
+  }
+}