refactor(bytes): minor cleanups (#4602)

bytes/concat.ts

@@ -4,7 +4,7 @@
 /**
  * Concatenate an array of byte slices into a single slice.
  *
- * @param buf Array of byte slices to concatenate.
+ * @param buffers Array of byte slices to concatenate.
  *
  * @example Basic usage
  * ```ts
@@ -16,16 +16,16 @@
  * concat([a, b]); // Uint8Array(6) [ 0, 1, 2, 3, 4, 5 ]
  * ```
  */
-export function concat(buf: Uint8Array[]): Uint8Array {
+export function concat(buffers: Uint8Array[]): Uint8Array {
   let length = 0;
-  for (const b of buf) {
-    length += b.length;
+  for (const buffer of buffers) {
+    length += buffer.length;
   }
   const output = new Uint8Array(length);
   let index = 0;
-  for (const b of buf) {
-    output.set(b, index);
-    index += b.length;
+  for (const buffer of buffers) {
+    output.set(buffer, index);
+    index += buffer.length;
   }
 
   return output;

bytes/copy.ts

@@ -2,10 +2,10 @@
 // This module is browser compatible.
 
 /**
- * Copy bytes from the `src` array to the `dst` array and returns the number of
- * bytes copied.
+ * Copy bytes from the source array to the destination array and returns the
+ * number of bytes copied.
  *
- * If the `src` array is larger than what the `dst` array can hold, only the
+ * If the source array is larger than what the `dst` array can hold, only the
  * amount of bytes that fit in the `dst` array are copied.
  *
  * @param src Source array to copy from.

bytes/ends_with.ts

@@ -23,10 +23,11 @@
  * ```
  */
 export function endsWith(source: Uint8Array, suffix: Uint8Array): boolean {
-  let srci = source.length - 1;
-  let sfxi = suffix.length - 1;
-  for (; sfxi >= 0; srci--, sfxi--) {
-    if (source[srci] !== suffix[sfxi]) return false;
+  const diff = source.length - suffix.length;
+  for (let i = suffix.length - 1; i >= 0; i--) {
+    if (source[diff + i] !== suffix[i]) {
+      return false;
+    }
   }
   return true;
 }

bytes/index_of_needle.ts

@@ -54,18 +54,14 @@ export function indexOfNeedle(
   const s = needle[0];
   for (let i = start; i < source.length; i++) {
     if (source[i] !== s) continue;
-    const pin = i;
     let matched = 1;
-    let j = i;
-    while (matched < needle.length) {
-      j++;
-      if (source[j] !== needle[j - pin]) {
-        break;
-      }
+    let j = i + 1;
+    while (matched < needle.length && source[j] === needle[j - i]) {
       matched++;
+      j++;
     }
     if (matched === needle.length) {
-      return pin;
+      return i;
     }
   }
   return -1;

bytes/last_index_of_needle.ts

@@ -51,18 +51,16 @@ export function lastIndexOfNeedle(
   const e = needle[needle.length - 1];
   for (let i = start; i >= 0; i--) {
     if (source[i] !== e) continue;
-    const pin = i;
     let matched = 1;
     let j = i;
-    while (matched < needle.length) {
-      j--;
-      if (source[j] !== needle[needle.length - 1 - (pin - j)]) {
-        break;
-      }
+    while (
+      matched < needle.length &&
+      source[--j] === needle[needle.length - 1 - (i - j)]
+    ) {
       matched++;
     }
     if (matched === needle.length) {
-      return pin - needle.length + 1;
+      return i - needle.length + 1;
     }
   }
   return -1;

bytes/repeat.ts

@@ -39,13 +39,12 @@ export function repeat(source: Uint8Array, count: number): Uint8Array {
     throw new Error("bytes: repeat count must be an integer");
   }
 
-  const nb = new Uint8Array(source.length * count);
+  const repeated = new Uint8Array(source.length * count);
+  let offset = 0;
 
-  let bp = copy(source, nb);
-
-  for (; bp < nb.length; bp *= 2) {
-    copy(nb.slice(0, bp), nb, bp);
+  while (offset < repeated.length) {
+    offset += copy(source, repeated, offset);
   }
 
-  return nb;
+  return repeated;
 }