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authorRyan Dahl <ry@tinyclouds.org>2019-10-10 05:31:23 -0400
committerGitHub <noreply@github.com>2019-10-10 05:31:23 -0400
commite7562eed8c816cd0d97aab6b818d7c8453dbaa2b (patch)
treec5a9f536e79d2c8d2d02897511a9138acaf35394 /std/io/ioutil.ts
parent3882c9d19a641e0c919f1350d87c6d7ee280cf78 (diff)
parent93f7f00c956c14620ef031626f124b57397ca867 (diff)
Merge deno_std in main repo (#3091)
The history of deno_std is persevered but rewritten to update links to issues and PRs Fixes denoland/deno_std#603
Diffstat (limited to 'std/io/ioutil.ts')
m---------std0
-rw-r--r--std/io/ioutil.ts79
2 files changed, 79 insertions, 0 deletions
diff --git a/std b/std
deleted file mode 160000
-Subproject 43aafbf33285753e7b42230f0eb7969b300f71c
diff --git a/std/io/ioutil.ts b/std/io/ioutil.ts
new file mode 100644
index 000000000..f1ca54e14
--- /dev/null
+++ b/std/io/ioutil.ts
@@ -0,0 +1,79 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import { BufReader, UnexpectedEOFError } from "./bufio.ts";
+type Reader = Deno.Reader;
+type Writer = Deno.Writer;
+import { assert } from "../testing/asserts.ts";
+
+/** copy N size at the most.
+ * If read size is lesser than N, then returns nread
+ * */
+export async function copyN(
+ dest: Writer,
+ r: Reader,
+ size: number
+): Promise<number> {
+ let bytesRead = 0;
+ let buf = new Uint8Array(1024);
+ while (bytesRead < size) {
+ if (size - bytesRead < 1024) {
+ buf = new Uint8Array(size - bytesRead);
+ }
+ const result = await r.read(buf);
+ const nread = result === Deno.EOF ? 0 : result;
+ bytesRead += nread;
+ if (nread > 0) {
+ const n = await dest.write(buf.slice(0, nread));
+ assert(n === nread, "could not write");
+ }
+ if (result === Deno.EOF) {
+ break;
+ }
+ }
+ return bytesRead;
+}
+
+/** Read big endian 16bit short from BufReader */
+export async function readShort(buf: BufReader): Promise<number | Deno.EOF> {
+ const high = await buf.readByte();
+ if (high === Deno.EOF) return Deno.EOF;
+ const low = await buf.readByte();
+ if (low === Deno.EOF) throw new UnexpectedEOFError();
+ return (high << 8) | low;
+}
+
+/** Read big endian 32bit integer from BufReader */
+export async function readInt(buf: BufReader): Promise<number | Deno.EOF> {
+ const high = await readShort(buf);
+ if (high === Deno.EOF) return Deno.EOF;
+ const low = await readShort(buf);
+ if (low === Deno.EOF) throw new UnexpectedEOFError();
+ return (high << 16) | low;
+}
+
+const MAX_SAFE_INTEGER = BigInt(Number.MAX_SAFE_INTEGER);
+
+/** Read big endian 64bit long from BufReader */
+export async function readLong(buf: BufReader): Promise<number | Deno.EOF> {
+ const high = await readInt(buf);
+ if (high === Deno.EOF) return Deno.EOF;
+ const low = await readInt(buf);
+ if (low === Deno.EOF) throw new UnexpectedEOFError();
+ const big = (BigInt(high) << 32n) | BigInt(low);
+ // We probably should provide a similar API that returns BigInt values.
+ if (big > MAX_SAFE_INTEGER) {
+ throw new RangeError(
+ "Long value too big to be represented as a Javascript number."
+ );
+ }
+ return Number(big);
+}
+
+/** Slice number into 64bit big endian byte array */
+export function sliceLongToBytes(d: number, dest = new Array(8)): number[] {
+ let big = BigInt(d);
+ for (let i = 0; i < 8; i++) {
+ dest[7 - i] = Number(big & 0xffn);
+ big >>= 8n;
+ }
+ return dest;
+}