diff options
author | Casper Beyer <caspervonb@pm.me> | 2021-02-02 19:05:46 +0800 |
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committer | GitHub <noreply@github.com> | 2021-02-02 12:05:46 +0100 |
commit | 6abf126c2a7a451cded8c6b5e6ddf1b69c84055d (patch) | |
tree | fd94c013a19fcb38954844085821ec1601c20e18 /std/node/string_decoder.ts | |
parent | a2b5d44f1aa9d64f448a2a3cc2001272e2f60b98 (diff) |
chore: remove std directory (#9361)
This removes the std folder from the tree.
Various parts of the tests are pretty tightly dependent
on std (47 direct imports and 75 indirect imports, not
counting the cli tests that use them as fixtures) so I've
added std as a submodule for now.
Diffstat (limited to 'std/node/string_decoder.ts')
-rw-r--r-- | std/node/string_decoder.ts | 313 |
1 files changed, 0 insertions, 313 deletions
diff --git a/std/node/string_decoder.ts b/std/node/string_decoder.ts deleted file mode 100644 index d5aba8018..000000000 --- a/std/node/string_decoder.ts +++ /dev/null @@ -1,313 +0,0 @@ -// Copyright Joyent, Inc. and other Node contributors. -// -// Permission is hereby granted, free of charge, to any person obtaining a -// copy of this software and associated documentation files (the -// "Software"), to deal in the Software without restriction, including -// without limitation the rights to use, copy, modify, merge, publish, -// distribute, sublicense, and/or sell copies of the Software, and to permit -// persons to whom the Software is furnished to do so, subject to the -// following conditions: -// -// The above copyright notice and this permission notice shall be included -// in all copies or substantial portions of the Software. -// -// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS -// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF -// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN -// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, -// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR -// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE -// USE OR OTHER DEALINGS IN THE SOFTWARE. - -import { Buffer } from "./buffer.ts"; -import { normalizeEncoding as castEncoding, notImplemented } from "./_utils.ts"; - -enum NotImplemented { - "ascii", - "latin1", - "utf16le", -} - -function normalizeEncoding(enc?: string): string { - const encoding = castEncoding(enc ?? null); - if (encoding && encoding in NotImplemented) notImplemented(encoding); - if (!encoding && typeof enc === "string" && enc.toLowerCase() !== "raw") { - throw new Error(`Unknown encoding: ${enc}`); - } - return String(encoding); -} -/* - * Checks the type of a UTF-8 byte, whether it's ASCII, a leading byte, or a - * continuation byte. If an invalid byte is detected, -2 is returned. - * */ -function utf8CheckByte(byte: number): number { - if (byte <= 0x7f) return 0; - else if (byte >> 5 === 0x06) return 2; - else if (byte >> 4 === 0x0e) return 3; - else if (byte >> 3 === 0x1e) return 4; - return byte >> 6 === 0x02 ? -1 : -2; -} - -/* - * Checks at most 3 bytes at the end of a Buffer in order to detect an - * incomplete multi-byte UTF-8 character. The total number of bytes (2, 3, or 4) - * needed to complete the UTF-8 character (if applicable) are returned. - * */ -function utf8CheckIncomplete( - self: StringDecoderBase, - buf: Buffer, - i: number, -): number { - let j = buf.length - 1; - if (j < i) return 0; - let nb = utf8CheckByte(buf[j]); - if (nb >= 0) { - if (nb > 0) self.lastNeed = nb - 1; - return nb; - } - if (--j < i || nb === -2) return 0; - nb = utf8CheckByte(buf[j]); - if (nb >= 0) { - if (nb > 0) self.lastNeed = nb - 2; - return nb; - } - if (--j < i || nb === -2) return 0; - nb = utf8CheckByte(buf[j]); - if (nb >= 0) { - if (nb > 0) { - if (nb === 2) nb = 0; - else self.lastNeed = nb - 3; - } - return nb; - } - return 0; -} - -/* - * Validates as many continuation bytes for a multi-byte UTF-8 character as - * needed or are available. If we see a non-continuation byte where we expect - * one, we "replace" the validated continuation bytes we've seen so far with - * a single UTF-8 replacement character ('\ufffd'), to match v8's UTF-8 decoding - * behavior. The continuation byte check is included three times in the case - * where all of the continuation bytes for a character exist in the same buffer. - * It is also done this way as a slight performance increase instead of using a - * loop. - * */ -function utf8CheckExtraBytes( - self: StringDecoderBase, - buf: Buffer, -): string | undefined { - if ((buf[0] & 0xc0) !== 0x80) { - self.lastNeed = 0; - return "\ufffd"; - } - if (self.lastNeed > 1 && buf.length > 1) { - if ((buf[1] & 0xc0) !== 0x80) { - self.lastNeed = 1; - return "\ufffd"; - } - if (self.lastNeed > 2 && buf.length > 2) { - if ((buf[2] & 0xc0) !== 0x80) { - self.lastNeed = 2; - return "\ufffd"; - } - } - } -} - -/* - * Attempts to complete a multi-byte UTF-8 character using bytes from a Buffer. - * */ -function utf8FillLastComplete( - this: StringDecoderBase, - buf: Buffer, -): string | undefined { - const p = this.lastTotal - this.lastNeed; - const r = utf8CheckExtraBytes(this, buf); - if (r !== undefined) return r; - if (this.lastNeed <= buf.length) { - buf.copy(this.lastChar, p, 0, this.lastNeed); - return this.lastChar.toString(this.encoding, 0, this.lastTotal); - } - buf.copy(this.lastChar, p, 0, buf.length); - this.lastNeed -= buf.length; -} - -/* - * Attempts to complete a partial non-UTF-8 character using bytes from a Buffer - * */ -function utf8FillLastIncomplete( - this: StringDecoderBase, - buf: Buffer, -): string | undefined { - if (this.lastNeed <= buf.length) { - buf.copy(this.lastChar, this.lastTotal - this.lastNeed, 0, this.lastNeed); - return this.lastChar.toString(this.encoding, 0, this.lastTotal); - } - buf.copy(this.lastChar, this.lastTotal - this.lastNeed, 0, buf.length); - this.lastNeed -= buf.length; -} - -/* - * Returns all complete UTF-8 characters in a Buffer. If the Buffer ended on a - * partial character, the character's bytes are buffered until the required - * number of bytes are available. - * */ -function utf8Text(this: StringDecoderBase, buf: Buffer, i: number): string { - const total = utf8CheckIncomplete(this, buf, i); - if (!this.lastNeed) return buf.toString("utf8", i); - this.lastTotal = total; - const end = buf.length - (total - this.lastNeed); - buf.copy(this.lastChar, 0, end); - return buf.toString("utf8", i, end); -} - -/* - * For UTF-8, a replacement character is added when ending on a partial - * character. - * */ -function utf8End(this: Utf8Decoder, buf?: Buffer): string { - const r = buf && buf.length ? this.write(buf) : ""; - if (this.lastNeed) return r + "\ufffd"; - return r; -} - -function utf8Write( - this: Utf8Decoder | Base64Decoder, - buf: Buffer | string, -): string { - if (typeof buf === "string") { - return buf; - } - if (buf.length === 0) return ""; - let r; - let i; - if (this.lastNeed) { - r = this.fillLast(buf); - if (r === undefined) return ""; - i = this.lastNeed; - this.lastNeed = 0; - } else { - i = 0; - } - if (i < buf.length) return r ? r + this.text(buf, i) : this.text(buf, i); - return r || ""; -} - -function base64Text(this: StringDecoderBase, buf: Buffer, i: number): string { - const n = (buf.length - i) % 3; - if (n === 0) return buf.toString("base64", i); - this.lastNeed = 3 - n; - this.lastTotal = 3; - if (n === 1) { - this.lastChar[0] = buf[buf.length - 1]; - } else { - this.lastChar[0] = buf[buf.length - 2]; - this.lastChar[1] = buf[buf.length - 1]; - } - return buf.toString("base64", i, buf.length - n); -} - -function base64End(this: Base64Decoder, buf?: Buffer): string { - const r = buf && buf.length ? this.write(buf) : ""; - if (this.lastNeed) { - return r + this.lastChar.toString("base64", 0, 3 - this.lastNeed); - } - return r; -} - -function simpleWrite( - this: StringDecoderBase, - buf: Buffer | string, -): string { - if (typeof buf === "string") { - return buf; - } - return buf.toString(this.encoding); -} - -function simpleEnd(this: GenericDecoder, buf?: Buffer): string { - return buf && buf.length ? this.write(buf) : ""; -} - -class StringDecoderBase { - public lastChar: Buffer; - public lastNeed = 0; - public lastTotal = 0; - constructor(public encoding: string, nb: number) { - this.lastChar = Buffer.allocUnsafe(nb); - } -} - -class Base64Decoder extends StringDecoderBase { - public end = base64End; - public fillLast = utf8FillLastIncomplete; - public text = base64Text; - public write = utf8Write; - - constructor(encoding?: string) { - super(normalizeEncoding(encoding), 3); - } -} - -class GenericDecoder extends StringDecoderBase { - public end = simpleEnd; - public fillLast = undefined; - public text = utf8Text; - public write = simpleWrite; - - constructor(encoding?: string) { - super(normalizeEncoding(encoding), 4); - } -} - -class Utf8Decoder extends StringDecoderBase { - public end = utf8End; - public fillLast = utf8FillLastComplete; - public text = utf8Text; - public write = utf8Write; - - constructor(encoding?: string) { - super(normalizeEncoding(encoding), 4); - } -} - -/* - * StringDecoder provides an interface for efficiently splitting a series of - * buffers into a series of JS strings without breaking apart multi-byte - * characters. - * */ -export class StringDecoder { - public encoding: string; - public end: (buf?: Buffer) => string; - public fillLast: ((buf: Buffer) => string | undefined) | undefined; - public lastChar: Buffer; - public lastNeed: number; - public lastTotal: number; - public text: (buf: Buffer, n: number) => string; - public write: (buf: Buffer) => string; - - constructor(encoding?: string) { - let decoder; - switch (encoding) { - case "utf8": - decoder = new Utf8Decoder(encoding); - break; - case "base64": - decoder = new Base64Decoder(encoding); - break; - default: - decoder = new GenericDecoder(encoding); - } - this.encoding = decoder.encoding; - this.end = decoder.end; - this.fillLast = decoder.fillLast; - this.lastChar = decoder.lastChar; - this.lastNeed = decoder.lastNeed; - this.lastTotal = decoder.lastTotal; - this.text = decoder.text; - this.write = decoder.write; - } -} - -export default { StringDecoder }; |