feat: multipart, etc.. (denoland/deno_std#180)

Original: https://github.com/denoland/deno_std/commit/fda9c98d055091fa886fa444ebd1adcd2ecd21bc

1 files changed, 60 insertions, 0 deletions

diff --git a/bytes/bytes.ts b/bytes/bytes.ts
new file mode 100644
index 000000000..ef333288e
--- /dev/null
+++ b/bytes/bytes.ts
@@ -0,0 +1,60 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+
+/** Find first index of binary pattern from a. If not found, then return -1 **/
+export function bytesFindIndex(a: Uint8Array, pat: Uint8Array): number {
+  const s = pat[0];
+  for (let i = 0; i < a.length; i++) {
+    if (a[i] !== s) continue;
+    const pin = i;
+    let matched = 1;
+    while (matched < pat.length) {
+      i++;
+      if (a[i] !== pat[i - pin]) {
+        break;
+      }
+      matched++;
+    }
+    if (matched === pat.length) {
+      return pin;
+    }
+  }
+  return -1;
+}
+
+/** Find last index of binary pattern from a. If not found, then return -1 **/
+export function bytesFindLastIndex(a: Uint8Array, pat: Uint8Array) {
+  const e = pat[pat.length - 1];
+  for (let i = a.length - 1; i >= 0; i--) {
+    if (a[i] !== e) continue;
+    const pin = i;
+    let matched = 1;
+    while (matched < pat.length) {
+      i--;
+      if (a[i] !== pat[pat.length - 1 - (pin - i)]) {
+        break;
+      }
+      matched++;
+    }
+    if (matched === pat.length) {
+      return pin - pat.length + 1;
+    }
+  }
+  return -1;
+}
+
+/** Check whether binary arrays are equal to each other **/
+export function bytesEqual(a: Uint8Array, match: Uint8Array): boolean {
+  if (a.length !== match.length) return false;
+  for (let i = 0; i < match.length; i++) {
+    if (a[i] !== match[i]) return false;
+  }
+  return true;
+}
+
+/** Check whether binary array has binary prefix  **/
+export function bytesHasPrefix(a: Uint8Array, prefix: Uint8Array): boolean {
+  for (let i = 0, max = prefix.length; i < max; i++) {
+    if (a[i] !== prefix[i]) return false;
+  }
+  return true;
+}