a collection of lightweight TypeScript packages for AT Protocol, the protocol powering Bluesky
atproto
bluesky
typescript
npm
feat(uint8array): add isUtf8LengthInRange function
+79
+5
.changeset/lovely-lines-love.md
+5
.changeset/lovely-lines-love.md
+12
packages/misc/uint8array/lib/index.bun.ts
+12
packages/misc/uint8array/lib/index.bun.ts
···
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return _byteLength(str, 'utf8');
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};
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/**
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* checks if a string's UTF-8 byte length is within a given range
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* @param str string to measure
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* @param min minimum byte length (inclusive)
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* @param max maximum byte length (inclusive)
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* @returns true if byte length is within [min, max]
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*/
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export const isUtf8LengthInRange = (str: string, min: number, max: number): boolean => {
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const len = _byteLength(str, 'utf8');
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return len >= min && len <= max;
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};
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+
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export const toSha256 = async (buffer: Uint8Array): Promise<Uint8Array<ArrayBuffer>> => {
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return toUint8Array(_hash('sha256', buffer, 'buffer')) as Uint8Array<ArrayBuffer>;
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};
+12
packages/misc/uint8array/lib/index.node.ts
+12
packages/misc/uint8array/lib/index.node.ts
···
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return _byteLength(str, 'utf8');
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};
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/**
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* checks if a string's UTF-8 byte length is within a given range
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* @param str string to measure
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* @param min minimum byte length (inclusive)
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* @param max maximum byte length (inclusive)
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* @returns true if byte length is within [min, max]
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*/
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export const isUtf8LengthInRange = (str: string, min: number, max: number): boolean => {
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const len = _byteLength(str, 'utf8');
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return len >= min && len <= max;
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};
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export const toSha256 = async (buffer: Uint8Array): Promise<Uint8Array<ArrayBuffer>> => {
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return toUint8Array(_hash('sha256', buffer, 'buffer')) as Uint8Array<ArrayBuffer>;
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};
+50
packages/misc/uint8array/lib/index.ts
+50
packages/misc/uint8array/lib/index.ts
···
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};
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/**
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* checks if a string's UTF-8 byte length is within a given range.
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* includes early-exit optimization when exceeding max length.
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* @param str string to measure
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* @param min minimum byte length (inclusive)
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* @param max maximum byte length (inclusive)
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* @returns true if byte length is within [min, max]
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*/
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export const isUtf8LengthInRange = (str: string, min: number, max: number): boolean => {
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const len = str.length;
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// fast path: if max possible UTF-8 length is below min, fail
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if (len * 3 < min) {
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return false;
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}
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+
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// fast path: if UTF-16 length satisfies min and max possible satisfies max
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if (len >= min && len * 3 <= max) {
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return true;
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}
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let u16pos = 0;
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let u8pos = 0;
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while (u16pos < len) {
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const code = str.charCodeAt(u16pos);
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if (code < 0x80) {
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u16pos += 1;
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u8pos += 1;
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} else if (code < 0x800) {
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u16pos += 1;
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u8pos += 2;
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} else if (code < 0xd800 || code > 0xdbff) {
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u16pos += 1;
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u8pos += 3;
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} else {
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u16pos += 2;
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u8pos += 4;
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}
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// early exit once we exceed max
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if (u8pos > max) {
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return false;
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}
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}
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return u8pos >= min;
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};
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/**
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* get a SHA-256 digest of this buffer
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*/
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export const toSha256 = async (buffer: Uint8Array<ArrayBuffer>): Promise<Uint8Array<ArrayBuffer>> => {