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authorAdam Mathes <adam@adammathes.com>2026-02-13 21:34:48 -0800
committerAdam Mathes <adam@adammathes.com>2026-02-13 21:34:48 -0800
commit76cb9c2a39d477a64824a985ade40507e3bbade1 (patch)
tree41e997aa9c6f538d3a136af61dae9424db2005a9 /vanilla/node_modules/@exodus/bytes/fallback/utf16.js
parent819a39a21ac992b1393244a4c283bbb125208c69 (diff)
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feat(vanilla): add testing infrastructure and tests (NK-wjnczv)
Diffstat (limited to 'vanilla/node_modules/@exodus/bytes/fallback/utf16.js')
-rw-r--r--vanilla/node_modules/@exodus/bytes/fallback/utf16.js266
1 files changed, 266 insertions, 0 deletions
diff --git a/vanilla/node_modules/@exodus/bytes/fallback/utf16.js b/vanilla/node_modules/@exodus/bytes/fallback/utf16.js
new file mode 100644
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+++ b/vanilla/node_modules/@exodus/bytes/fallback/utf16.js
@@ -0,0 +1,266 @@
+import { decodeUCS2 } from './latin1.js'
+import { assertU8, E_STRING, E_STRICT_UNICODE } from './_utils.js'
+import { nativeDecoder, isLE, encodeCharcodes } from './platform.js'
+
+export const E_STRICT = 'Input is not well-formed utf16'
+const isWellFormedStr = /* @__PURE__ */ (() => String.prototype.isWellFormed)()
+const toWellFormedStr = /* @__PURE__ */ (() => String.prototype.toWellFormed)()
+
+const replacementCodepoint = 0xff_fd
+const replacementCodepointSwapped = 0xfd_ff
+
+const to16 = (a) => new Uint16Array(a.buffer, a.byteOffset, a.byteLength / 2) // Requires checked length and alignment!
+
+export function encodeApi(str, loose, format) {
+ if (typeof str !== 'string') throw new TypeError(E_STRING)
+ if (format !== 'uint16' && format !== 'uint8-le' && format !== 'uint8-be') {
+ throw new TypeError('Unknown format')
+ }
+
+ // On v8 and SpiderMonkey, check via isWellFormed is faster than js
+ // On JSC, check during loop is faster than isWellFormed
+ // If isWellFormed is available, we skip check during decoding and recheck after
+ // If isWellFormed is unavailable, we check in js during decoding
+ if (!loose && isWellFormedStr && !isWellFormedStr.call(str)) throw new TypeError(E_STRICT_UNICODE)
+ const shouldSwap = (isLE && format === 'uint8-be') || (!isLE && format === 'uint8-le')
+ const u16 = encode(str, loose, !loose && isWellFormedStr, shouldSwap)
+
+ // Bytes are already swapped and format is already checked, we need to just cast the view
+ return format === 'uint16' ? u16 : new Uint8Array(u16.buffer, u16.byteOffset, u16.byteLength)
+}
+
+const fatalLE = nativeDecoder ? new TextDecoder('utf-16le', { ignoreBOM: true, fatal: true }) : null
+const looseLE = nativeDecoder ? new TextDecoder('utf-16le', { ignoreBOM: true }) : null
+const fatalBE = nativeDecoder ? new TextDecoder('utf-16be', { ignoreBOM: true, fatal: true }) : null
+const looseBE = nativeDecoder ? new TextDecoder('utf-16be', { ignoreBOM: true }) : null
+
+export function decodeApiDecoders(input, loose, format) {
+ if (format === 'uint16') {
+ if (!(input instanceof Uint16Array)) throw new TypeError('Expected an Uint16Array')
+ } else if (format === 'uint8-le' || format === 'uint8-be') {
+ assertU8(input)
+ if (input.byteLength % 2 !== 0) throw new TypeError('Expected even number of bytes')
+ } else {
+ throw new TypeError('Unknown format')
+ }
+
+ const le = format === 'uint8-le' || (format === 'uint16' && isLE)
+ return (le ? (loose ? looseLE : fatalLE) : loose ? looseBE : fatalBE).decode(input)
+}
+
+export function decodeApiJS(input, loose, format) {
+ let u16
+ switch (format) {
+ case 'uint16':
+ if (!(input instanceof Uint16Array)) throw new TypeError('Expected an Uint16Array')
+ u16 = input
+ break
+ case 'uint8-le':
+ assertU8(input)
+ if (input.byteLength % 2 !== 0) throw new TypeError('Expected even number of bytes')
+ u16 = to16input(input, true)
+ break
+ case 'uint8-be':
+ assertU8(input)
+ if (input.byteLength % 2 !== 0) throw new TypeError('Expected even number of bytes')
+ u16 = to16input(input, false)
+ break
+ default:
+ throw new TypeError('Unknown format')
+ }
+
+ const str = decode(u16, loose, (!loose && isWellFormedStr) || (loose && toWellFormedStr))
+ if (!loose && isWellFormedStr && !isWellFormedStr.call(str)) throw new TypeError(E_STRICT)
+ if (loose && toWellFormedStr) return toWellFormedStr.call(str)
+
+ return str
+}
+
+export function to16input(u8, le) {
+ // Assume even number of bytes
+ if (le === isLE) return to16(u8.byteOffset % 2 === 0 ? u8 : Uint8Array.from(u8))
+ return to16(swap16(Uint8Array.from(u8)))
+}
+
+export const decode = (u16, loose = false, checked = false) => {
+ if (checked || isWellFormed(u16)) return decodeUCS2(u16)
+ if (!loose) throw new TypeError(E_STRICT)
+ return decodeUCS2(toWellFormed(Uint16Array.from(u16))) // cloned for replacement
+}
+
+export function encode(str, loose = false, checked = false, swapped = false) {
+ const arr = new Uint16Array(str.length)
+ if (checked) return swapped ? encodeCheckedSwapped(str, arr) : encodeChecked(str, arr)
+ return swapped ? encodeUncheckedSwapped(str, arr, loose) : encodeUnchecked(str, arr, loose)
+}
+
+/* eslint-disable @exodus/mutable/no-param-reassign-prop-only */
+
+// Assumes checked length % 2 === 0, otherwise does not swap tail
+function swap16(u8) {
+ let i = 0
+ for (const last3 = u8.length - 3; i < last3; i += 4) {
+ const x0 = u8[i]
+ const x1 = u8[i + 1]
+ const x2 = u8[i + 2]
+ const x3 = u8[i + 3]
+ u8[i] = x1
+ u8[i + 1] = x0
+ u8[i + 2] = x3
+ u8[i + 3] = x2
+ }
+
+ for (const last = u8.length - 1; i < last; i += 2) {
+ const x0 = u8[i]
+ const x1 = u8[i + 1]
+ u8[i] = x1
+ u8[i + 1] = x0
+ }
+
+ return u8
+}
+
+// Splitting paths into small functions helps (at least on SpiderMonkey)
+
+const encodeChecked = (str, arr) => encodeCharcodes(str, arr) // Same as encodeLatin1, but with Uint16Array
+
+function encodeCheckedSwapped(str, arr) {
+ // TODO: faster path for Hermes? See encodeCharcodes
+ const length = str.length
+ for (let i = 0; i < length; i++) {
+ const x = str.charCodeAt(i)
+ arr[i] = ((x & 0xff) << 8) | (x >> 8)
+ }
+
+ return arr
+}
+
+// lead: d800 - dbff, trail: dc00 - dfff
+
+function encodeUnchecked(str, arr, loose = false) {
+ // TODO: faster path for Hermes? See encodeCharcodes
+ const length = str.length
+ for (let i = 0; i < length; i++) {
+ const code = str.charCodeAt(i)
+ arr[i] = code
+ if (code >= 0xd8_00 && code < 0xe0_00) {
+ // An unexpected trail or a lead at the very end of input
+ if (code > 0xdb_ff || i + 1 >= length) {
+ if (!loose) throw new TypeError(E_STRICT_UNICODE)
+ arr[i] = replacementCodepoint
+ } else {
+ const next = str.charCodeAt(i + 1) // Process valid pairs immediately
+ if (next < 0xdc_00 || next >= 0xe0_00) {
+ if (!loose) throw new TypeError(E_STRICT_UNICODE)
+ arr[i] = replacementCodepoint
+ } else {
+ i++ // consume next
+ arr[i] = next
+ }
+ }
+ }
+ }
+
+ return arr
+}
+
+function encodeUncheckedSwapped(str, arr, loose = false) {
+ // TODO: faster path for Hermes? See encodeCharcodes
+ const length = str.length
+ for (let i = 0; i < length; i++) {
+ const code = str.charCodeAt(i)
+ arr[i] = ((code & 0xff) << 8) | (code >> 8)
+ if (code >= 0xd8_00 && code < 0xe0_00) {
+ // An unexpected trail or a lead at the very end of input
+ if (code > 0xdb_ff || i + 1 >= length) {
+ if (!loose) throw new TypeError(E_STRICT_UNICODE)
+ arr[i] = replacementCodepointSwapped
+ } else {
+ const next = str.charCodeAt(i + 1) // Process valid pairs immediately
+ if (next < 0xdc_00 || next >= 0xe0_00) {
+ if (!loose) throw new TypeError(E_STRICT_UNICODE)
+ arr[i] = replacementCodepointSwapped
+ } else {
+ i++ // consume next
+ arr[i] = ((next & 0xff) << 8) | (next >> 8)
+ }
+ }
+ }
+ }
+
+ return arr
+}
+
+// Only needed on Hermes, everything else has native impl
+export function toWellFormed(u16) {
+ const length = u16.length
+ for (let i = 0; i < length; i++) {
+ const code = u16[i]
+ if (code >= 0xd8_00 && code < 0xe0_00) {
+ // An unexpected trail or a lead at the very end of input
+ if (code > 0xdb_ff || i + 1 >= length) {
+ u16[i] = replacementCodepoint
+ } else {
+ const next = u16[i + 1] // Process valid pairs immediately
+ if (next < 0xdc_00 || next >= 0xe0_00) {
+ u16[i] = replacementCodepoint
+ } else {
+ i++ // consume next
+ }
+ }
+ }
+ }
+
+ return u16
+}
+
+// Only needed on Hermes, everything else has native impl
+export function isWellFormed(u16) {
+ const length = u16.length
+ let i = 0
+
+ const m = 0x80_00_80_00
+ const l = 0xd8_00
+ const h = 0xe0_00
+
+ // Speedup with u32, by skipping to the first surrogate
+ // Only implemented for aligned input for now, but almost all input is aligned (pooled Buffer or 0 offset)
+ if (length > 32 && u16.byteOffset % 4 === 0) {
+ const u32length = (u16.byteLength / 4) | 0
+ const u32 = new Uint32Array(u16.buffer, u16.byteOffset, u32length)
+ for (const last3 = u32length - 3; ; i += 4) {
+ if (i >= last3) break // loop is fast enough for moving this here to be _very_ useful, likely due to array access checks
+ const a = u32[i]
+ const b = u32[i + 1]
+ const c = u32[i + 2]
+ const d = u32[i + 3]
+ if (a & m || b & m || c & m || d & m) break // bitwise OR does not make this faster on Hermes
+ }
+
+ for (; i < u32length; i++) if (u32[i] & m) break
+ i *= 2
+ }
+
+ // An extra loop gives ~30-40% speedup e.g. on English text without surrogates but with other symbols above 0x80_00
+ for (const last3 = length - 3; ; i += 4) {
+ if (i >= last3) break
+ const a = u16[i]
+ const b = u16[i + 1]
+ const c = u16[i + 2]
+ const d = u16[i + 3]
+ if ((a >= l && a < h) || (b >= l && b < h) || (c >= l && c < h) || (d >= l && d < h)) break
+ }
+
+ for (; i < length; i++) {
+ const code = u16[i]
+ if (code >= l && code < h) {
+ // An unexpected trail or a lead at the very end of input
+ if (code >= 0xdc_00 || i + 1 >= length) return false
+ i++ // consume next
+ const next = u16[i] // Process valid pairs immediately
+ if (next < 0xdc_00 || next >= h) return false
+ }
+ }
+
+ return true
+}