diff options
Diffstat (limited to 'fastify-busboy/deps')
| -rw-r--r-- | fastify-busboy/deps/dicer/LICENSE | 19 | ||||
| -rw-r--r-- | fastify-busboy/deps/dicer/lib/Dicer.js | 207 | ||||
| -rw-r--r-- | fastify-busboy/deps/dicer/lib/HeaderParser.js | 100 | ||||
| -rw-r--r-- | fastify-busboy/deps/dicer/lib/PartStream.js | 13 | ||||
| -rw-r--r-- | fastify-busboy/deps/dicer/lib/dicer.d.ts | 164 | ||||
| -rw-r--r-- | fastify-busboy/deps/streamsearch/sbmh.js | 228 |
6 files changed, 731 insertions, 0 deletions
diff --git a/fastify-busboy/deps/dicer/LICENSE b/fastify-busboy/deps/dicer/LICENSE new file mode 100644 index 0000000..290762e --- /dev/null +++ b/fastify-busboy/deps/dicer/LICENSE @@ -0,0 +1,19 @@ +Copyright Brian White. All rights reserved. + +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.
\ No newline at end of file diff --git a/fastify-busboy/deps/dicer/lib/Dicer.js b/fastify-busboy/deps/dicer/lib/Dicer.js new file mode 100644 index 0000000..79da160 --- /dev/null +++ b/fastify-busboy/deps/dicer/lib/Dicer.js @@ -0,0 +1,207 @@ +'use strict' + +const WritableStream = require('node:stream').Writable +const inherits = require('node:util').inherits + +const StreamSearch = require('../../streamsearch/sbmh') + +const PartStream = require('./PartStream') +const HeaderParser = require('./HeaderParser') + +const DASH = 45 +const B_ONEDASH = Buffer.from('-') +const B_CRLF = Buffer.from('\r\n') +const EMPTY_FN = function () {} + +function Dicer (cfg) { + if (!(this instanceof Dicer)) { return new Dicer(cfg) } + WritableStream.call(this, cfg) + + if (!cfg || (!cfg.headerFirst && typeof cfg.boundary !== 'string')) { throw new TypeError('Boundary required') } + + if (typeof cfg.boundary === 'string') { this.setBoundary(cfg.boundary) } else { this._bparser = undefined } + + this._headerFirst = cfg.headerFirst + + this._dashes = 0 + this._parts = 0 + this._finished = false + this._realFinish = false + this._isPreamble = true + this._justMatched = false + this._firstWrite = true + this._inHeader = true + this._part = undefined + this._cb = undefined + this._ignoreData = false + this._partOpts = { highWaterMark: cfg.partHwm } + this._pause = false + + const self = this + this._hparser = new HeaderParser(cfg) + this._hparser.on('header', function (header) { + self._inHeader = false + self._part.emit('header', header) + }) +} +inherits(Dicer, WritableStream) + +Dicer.prototype.emit = function (ev) { + if (ev === 'finish' && !this._realFinish) { + if (!this._finished) { + const self = this + process.nextTick(function () { + self.emit('error', new Error('Unexpected end of multipart data')) + if (self._part && !self._ignoreData) { + const type = (self._isPreamble ? 'Preamble' : 'Part') + self._part.emit('error', new Error(type + ' terminated early due to unexpected end of multipart data')) + self._part.push(null) + process.nextTick(function () { + self._realFinish = true + self.emit('finish') + self._realFinish = false + }) + return + } + self._realFinish = true + self.emit('finish') + self._realFinish = false + }) + } + } else { WritableStream.prototype.emit.apply(this, arguments) } +} + +Dicer.prototype._write = function (data, encoding, cb) { + // ignore unexpected data (e.g. extra trailer data after finished) + if (!this._hparser && !this._bparser) { return cb() } + + if (this._headerFirst && this._isPreamble) { + if (!this._part) { + this._part = new PartStream(this._partOpts) + if (this._events.preamble) { this.emit('preamble', this._part) } else { this._ignore() } + } + const r = this._hparser.push(data) + if (!this._inHeader && r !== undefined && r < data.length) { data = data.slice(r) } else { return cb() } + } + + // allows for "easier" testing + if (this._firstWrite) { + this._bparser.push(B_CRLF) + this._firstWrite = false + } + + this._bparser.push(data) + + if (this._pause) { this._cb = cb } else { cb() } +} + +Dicer.prototype.reset = function () { + this._part = undefined + this._bparser = undefined + this._hparser = undefined +} + +Dicer.prototype.setBoundary = function (boundary) { + const self = this + this._bparser = new StreamSearch('\r\n--' + boundary) + this._bparser.on('info', function (isMatch, data, start, end) { + self._oninfo(isMatch, data, start, end) + }) +} + +Dicer.prototype._ignore = function () { + if (this._part && !this._ignoreData) { + this._ignoreData = true + this._part.on('error', EMPTY_FN) + // we must perform some kind of read on the stream even though we are + // ignoring the data, otherwise node's Readable stream will not emit 'end' + // after pushing null to the stream + this._part.resume() + } +} + +Dicer.prototype._oninfo = function (isMatch, data, start, end) { + let buf; const self = this; let i = 0; let r; let shouldWriteMore = true + + if (!this._part && this._justMatched && data) { + while (this._dashes < 2 && (start + i) < end) { + if (data[start + i] === DASH) { + ++i + ++this._dashes + } else { + if (this._dashes) { buf = B_ONEDASH } + this._dashes = 0 + break + } + } + if (this._dashes === 2) { + if ((start + i) < end && this._events.trailer) { this.emit('trailer', data.slice(start + i, end)) } + this.reset() + this._finished = true + // no more parts will be added + if (self._parts === 0) { + self._realFinish = true + self.emit('finish') + self._realFinish = false + } + } + if (this._dashes) { return } + } + if (this._justMatched) { this._justMatched = false } + if (!this._part) { + this._part = new PartStream(this._partOpts) + this._part._read = function (n) { + self._unpause() + } + if (this._isPreamble && this._events.preamble) { this.emit('preamble', this._part) } else if (this._isPreamble !== true && this._events.part) { this.emit('part', this._part) } else { this._ignore() } + if (!this._isPreamble) { this._inHeader = true } + } + if (data && start < end && !this._ignoreData) { + if (this._isPreamble || !this._inHeader) { + if (buf) { shouldWriteMore = this._part.push(buf) } + shouldWriteMore = this._part.push(data.slice(start, end)) + if (!shouldWriteMore) { this._pause = true } + } else if (!this._isPreamble && this._inHeader) { + if (buf) { this._hparser.push(buf) } + r = this._hparser.push(data.slice(start, end)) + if (!this._inHeader && r !== undefined && r < end) { this._oninfo(false, data, start + r, end) } + } + } + if (isMatch) { + this._hparser.reset() + if (this._isPreamble) { this._isPreamble = false } else { + if (start !== end) { + ++this._parts + this._part.on('end', function () { + if (--self._parts === 0) { + if (self._finished) { + self._realFinish = true + self.emit('finish') + self._realFinish = false + } else { + self._unpause() + } + } + }) + } + } + this._part.push(null) + this._part = undefined + this._ignoreData = false + this._justMatched = true + this._dashes = 0 + } +} + +Dicer.prototype._unpause = function () { + if (!this._pause) { return } + + this._pause = false + if (this._cb) { + const cb = this._cb + this._cb = undefined + cb() + } +} + +module.exports = Dicer diff --git a/fastify-busboy/deps/dicer/lib/HeaderParser.js b/fastify-busboy/deps/dicer/lib/HeaderParser.js new file mode 100644 index 0000000..65f667b --- /dev/null +++ b/fastify-busboy/deps/dicer/lib/HeaderParser.js @@ -0,0 +1,100 @@ +'use strict' + +const EventEmitter = require('node:events').EventEmitter +const inherits = require('node:util').inherits +const getLimit = require('../../../lib/utils/getLimit') + +const StreamSearch = require('../../streamsearch/sbmh') + +const B_DCRLF = Buffer.from('\r\n\r\n') +const RE_CRLF = /\r\n/g +const RE_HDR = /^([^:]+):[ \t]?([\x00-\xFF]+)?$/ // eslint-disable-line no-control-regex + +function HeaderParser (cfg) { + EventEmitter.call(this) + + cfg = cfg || {} + const self = this + this.nread = 0 + this.maxed = false + this.npairs = 0 + this.maxHeaderPairs = getLimit(cfg, 'maxHeaderPairs', 2000) + this.maxHeaderSize = getLimit(cfg, 'maxHeaderSize', 80 * 1024) + this.buffer = '' + this.header = {} + this.finished = false + this.ss = new StreamSearch(B_DCRLF) + this.ss.on('info', function (isMatch, data, start, end) { + if (data && !self.maxed) { + if (self.nread + end - start >= self.maxHeaderSize) { + end = self.maxHeaderSize - self.nread + start + self.nread = self.maxHeaderSize + self.maxed = true + } else { self.nread += (end - start) } + + self.buffer += data.toString('binary', start, end) + } + if (isMatch) { self._finish() } + }) +} +inherits(HeaderParser, EventEmitter) + +HeaderParser.prototype.push = function (data) { + const r = this.ss.push(data) + if (this.finished) { return r } +} + +HeaderParser.prototype.reset = function () { + this.finished = false + this.buffer = '' + this.header = {} + this.ss.reset() +} + +HeaderParser.prototype._finish = function () { + if (this.buffer) { this._parseHeader() } + this.ss.matches = this.ss.maxMatches + const header = this.header + this.header = {} + this.buffer = '' + this.finished = true + this.nread = this.npairs = 0 + this.maxed = false + this.emit('header', header) +} + +HeaderParser.prototype._parseHeader = function () { + if (this.npairs === this.maxHeaderPairs) { return } + + const lines = this.buffer.split(RE_CRLF) + const len = lines.length + let m, h + + for (var i = 0; i < len; ++i) { // eslint-disable-line no-var + if (lines[i].length === 0) { continue } + if (lines[i][0] === '\t' || lines[i][0] === ' ') { + // folded header content + // RFC2822 says to just remove the CRLF and not the whitespace following + // it, so we follow the RFC and include the leading whitespace ... + if (h) { + this.header[h][this.header[h].length - 1] += lines[i] + continue + } + } + + const posColon = lines[i].indexOf(':') + if ( + posColon === -1 || + posColon === 0 + ) { + return + } + m = RE_HDR.exec(lines[i]) + h = m[1].toLowerCase() + this.header[h] = this.header[h] || [] + this.header[h].push((m[2] || '')) + if (++this.npairs === this.maxHeaderPairs) { break } + } +} + +module.exports = HeaderParser diff --git a/fastify-busboy/deps/dicer/lib/PartStream.js b/fastify-busboy/deps/dicer/lib/PartStream.js new file mode 100644 index 0000000..c91da1c --- /dev/null +++ b/fastify-busboy/deps/dicer/lib/PartStream.js @@ -0,0 +1,13 @@ +'use strict' + +const inherits = require('node:util').inherits +const ReadableStream = require('node:stream').Readable + +function PartStream (opts) { + ReadableStream.call(this, opts) +} +inherits(PartStream, ReadableStream) + +PartStream.prototype._read = function (n) {} + +module.exports = PartStream diff --git a/fastify-busboy/deps/dicer/lib/dicer.d.ts b/fastify-busboy/deps/dicer/lib/dicer.d.ts new file mode 100644 index 0000000..3c5b896 --- /dev/null +++ b/fastify-busboy/deps/dicer/lib/dicer.d.ts @@ -0,0 +1,164 @@ +// Type definitions for dicer 0.2 +// Project: https://github.com/mscdex/dicer +// Definitions by: BendingBender <https://github.com/BendingBender> +// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped +// TypeScript Version: 2.2 +/// <reference types="node" /> + +import stream = require("stream"); + +// tslint:disable:unified-signatures + +/** + * A very fast streaming multipart parser for node.js. + * Dicer is a WritableStream + * + * Dicer (special) events: + * - on('finish', ()) - Emitted when all parts have been parsed and the Dicer instance has been ended. + * - on('part', (stream: PartStream)) - Emitted when a new part has been found. + * - on('preamble', (stream: PartStream)) - Emitted for preamble if you should happen to need it (can usually be ignored). + * - on('trailer', (data: Buffer)) - Emitted when trailing data was found after the terminating boundary (as with the preamble, this can usually be ignored too). + */ +export class Dicer extends stream.Writable { + /** + * Creates and returns a new Dicer instance with the following valid config settings: + * + * @param config The configuration to use + */ + constructor(config: Dicer.Config); + /** + * Sets the boundary to use for parsing and performs some initialization needed for parsing. + * You should only need to use this if you set headerFirst to true in the constructor and are parsing the boundary from the preamble header. + * + * @param boundary The boundary to use + */ + setBoundary(boundary: string): void; + addListener(event: "finish", listener: () => void): this; + addListener(event: "part", listener: (stream: Dicer.PartStream) => void): this; + addListener(event: "preamble", listener: (stream: Dicer.PartStream) => void): this; + addListener(event: "trailer", listener: (data: Buffer) => void): this; + addListener(event: "close", listener: () => void): this; + addListener(event: "drain", listener: () => void): this; + addListener(event: "error", listener: (err: Error) => void): this; + addListener(event: "pipe", listener: (src: stream.Readable) => void): this; + addListener(event: "unpipe", listener: (src: stream.Readable) => void): this; + addListener(event: string, listener: (...args: any[]) => void): this; + on(event: "finish", listener: () => void): this; + on(event: "part", listener: (stream: Dicer.PartStream) => void): this; + on(event: "preamble", listener: (stream: Dicer.PartStream) => void): this; + on(event: "trailer", listener: (data: Buffer) => void): this; + on(event: "close", listener: () => void): this; + on(event: "drain", listener: () => void): this; + on(event: "error", listener: (err: Error) => void): this; + on(event: "pipe", listener: (src: stream.Readable) => void): this; + on(event: "unpipe", listener: (src: stream.Readable) => void): this; + on(event: string, listener: (...args: any[]) => void): this; + once(event: "finish", listener: () => void): this; + once(event: "part", listener: (stream: Dicer.PartStream) => void): this; + once(event: "preamble", listener: (stream: Dicer.PartStream) => void): this; + once(event: "trailer", listener: (data: Buffer) => void): this; + once(event: "close", listener: () => void): this; + once(event: "drain", listener: () => void): this; + once(event: "error", listener: (err: Error) => void): this; + once(event: "pipe", listener: (src: stream.Readable) => void): this; + once(event: "unpipe", listener: (src: stream.Readable) => void): this; + once(event: string, listener: (...args: any[]) => void): this; + prependListener(event: "finish", listener: () => void): this; + prependListener(event: "part", listener: (stream: Dicer.PartStream) => void): this; + prependListener(event: "preamble", listener: (stream: Dicer.PartStream) => void): this; + prependListener(event: "trailer", listener: (data: Buffer) => void): this; + prependListener(event: "close", listener: () => void): this; + prependListener(event: "drain", listener: () => void): this; + prependListener(event: "error", listener: (err: Error) => void): this; + prependListener(event: "pipe", listener: (src: stream.Readable) => void): this; + prependListener(event: "unpipe", listener: (src: stream.Readable) => void): this; + prependListener(event: string, listener: (...args: any[]) => void): this; + prependOnceListener(event: "finish", listener: () => void): this; + prependOnceListener(event: "part", listener: (stream: Dicer.PartStream) => void): this; + prependOnceListener(event: "preamble", listener: (stream: Dicer.PartStream) => void): this; + prependOnceListener(event: "trailer", listener: (data: Buffer) => void): this; + prependOnceListener(event: "close", listener: () => void): this; + prependOnceListener(event: "drain", listener: () => void): this; + prependOnceListener(event: "error", listener: (err: Error) => void): this; + prependOnceListener(event: "pipe", listener: (src: stream.Readable) => void): this; + prependOnceListener(event: "unpipe", listener: (src: stream.Readable) => void): this; + prependOnceListener(event: string, listener: (...args: any[]) => void): this; + removeListener(event: "finish", listener: () => void): this; + removeListener(event: "part", listener: (stream: Dicer.PartStream) => void): this; + removeListener(event: "preamble", listener: (stream: Dicer.PartStream) => void): this; + removeListener(event: "trailer", listener: (data: Buffer) => void): this; + removeListener(event: "close", listener: () => void): this; + removeListener(event: "drain", listener: () => void): this; + removeListener(event: "error", listener: (err: Error) => void): this; + removeListener(event: "pipe", listener: (src: stream.Readable) => void): this; + removeListener(event: "unpipe", listener: (src: stream.Readable) => void): this; + removeListener(event: string, listener: (...args: any[]) => void): this; +} + +declare namespace Dicer { + interface Config { + /** + * This is the boundary used to detect the beginning of a new part. + */ + boundary?: string | undefined; + /** + * If true, preamble header parsing will be performed first. + */ + headerFirst?: boolean | undefined; + /** + * The maximum number of header key=>value pairs to parse Default: 2000 (same as node's http). + */ + maxHeaderPairs?: number | undefined; + } + + /** + * PartStream is a _ReadableStream_ + * + * PartStream (special) events: + * - on('header', (header: object)) - An object containing the header for this particular part. Each property value is an array of one or more string values. + */ + interface PartStream extends stream.Readable { + addListener(event: "header", listener: (header: object) => void): this; + addListener(event: "close", listener: () => void): this; + addListener(event: "data", listener: (chunk: Buffer | string) => void): this; + addListener(event: "end", listener: () => void): this; + addListener(event: "readable", listener: () => void): this; + addListener(event: "error", listener: (err: Error) => void): this; + addListener(event: string, listener: (...args: any[]) => void): this; + on(event: "header", listener: (header: object) => void): this; + on(event: "close", listener: () => void): this; + on(event: "data", listener: (chunk: Buffer | string) => void): this; + on(event: "end", listener: () => void): this; + on(event: "readable", listener: () => void): this; + on(event: "error", listener: (err: Error) => void): this; + on(event: string, listener: (...args: any[]) => void): this; + once(event: "header", listener: (header: object) => void): this; + once(event: "close", listener: () => void): this; + once(event: "data", listener: (chunk: Buffer | string) => void): this; + once(event: "end", listener: () => void): this; + once(event: "readable", listener: () => void): this; + once(event: "error", listener: (err: Error) => void): this; + once(event: string, listener: (...args: any[]) => void): this; + prependListener(event: "header", listener: (header: object) => void): this; + prependListener(event: "close", listener: () => void): this; + prependListener(event: "data", listener: (chunk: Buffer | string) => void): this; + prependListener(event: "end", listener: () => void): this; + prependListener(event: "readable", listener: () => void): this; + prependListener(event: "error", listener: (err: Error) => void): this; + prependListener(event: string, listener: (...args: any[]) => void): this; + prependOnceListener(event: "header", listener: (header: object) => void): this; + prependOnceListener(event: "close", listener: () => void): this; + prependOnceListener(event: "data", listener: (chunk: Buffer | string) => void): this; + prependOnceListener(event: "end", listener: () => void): this; + prependOnceListener(event: "readable", listener: () => void): this; + prependOnceListener(event: "error", listener: (err: Error) => void): this; + prependOnceListener(event: string, listener: (...args: any[]) => void): this; + removeListener(event: "header", listener: (header: object) => void): this; + removeListener(event: "close", listener: () => void): this; + removeListener(event: "data", listener: (chunk: Buffer | string) => void): this; + removeListener(event: "end", listener: () => void): this; + removeListener(event: "readable", listener: () => void): this; + removeListener(event: "error", listener: (err: Error) => void): this; + removeListener(event: string, listener: (...args: any[]) => void): this; + } +}
\ No newline at end of file diff --git a/fastify-busboy/deps/streamsearch/sbmh.js b/fastify-busboy/deps/streamsearch/sbmh.js new file mode 100644 index 0000000..b90c0e8 --- /dev/null +++ b/fastify-busboy/deps/streamsearch/sbmh.js @@ -0,0 +1,228 @@ +'use strict' + +/** + * Copyright Brian White. All rights reserved. + * + * @see https://github.com/mscdex/streamsearch + * + * 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. + * + * Based heavily on the Streaming Boyer-Moore-Horspool C++ implementation + * by Hongli Lai at: https://github.com/FooBarWidget/boyer-moore-horspool + */ +const EventEmitter = require('node:events').EventEmitter +const inherits = require('node:util').inherits + +function SBMH (needle) { + if (typeof needle === 'string') { + needle = Buffer.from(needle) + } + + if (!Buffer.isBuffer(needle)) { + throw new TypeError('The needle has to be a String or a Buffer.') + } + + const needleLength = needle.length + + if (needleLength === 0) { + throw new Error('The needle cannot be an empty String/Buffer.') + } + + if (needleLength > 256) { + throw new Error('The needle cannot have a length bigger than 256.') + } + + this.maxMatches = Infinity + this.matches = 0 + + this._occ = new Array(256) + .fill(needleLength) // Initialize occurrence table. + this._lookbehind_size = 0 + this._needle = needle + this._bufpos = 0 + + this._lookbehind = Buffer.alloc(needleLength) + + // Populate occurrence table with analysis of the needle, + // ignoring last letter. + for (var i = 0; i < needleLength - 1; ++i) { // eslint-disable-line no-var + this._occ[needle[i]] = needleLength - 1 - i + } +} +inherits(SBMH, EventEmitter) + +SBMH.prototype.reset = function () { + this._lookbehind_size = 0 + this.matches = 0 + this._bufpos = 0 +} + +SBMH.prototype.push = function (chunk, pos) { + if (!Buffer.isBuffer(chunk)) { + chunk = Buffer.from(chunk, 'binary') + } + const chlen = chunk.length + this._bufpos = pos || 0 + let r + while (r !== chlen && this.matches < this.maxMatches) { r = this._sbmh_feed(chunk) } + return r +} + +SBMH.prototype._sbmh_feed = function (data) { + const len = data.length + const needle = this._needle + const needleLength = needle.length + const lastNeedleChar = needle[needleLength - 1] + + // Positive: points to a position in `data` + // pos == 3 points to data[3] + // Negative: points to a position in the lookbehind buffer + // pos == -2 points to lookbehind[lookbehind_size - 2] + let pos = -this._lookbehind_size + let ch + + if (pos < 0) { + // Lookbehind buffer is not empty. Perform Boyer-Moore-Horspool + // search with character lookup code that considers both the + // lookbehind buffer and the current round's haystack data. + // + // Loop until + // there is a match. + // or until + // we've moved past the position that requires the + // lookbehind buffer. In this case we switch to the + // optimized loop. + // or until + // the character to look at lies outside the haystack. + while (pos < 0 && pos <= len - needleLength) { + ch = this._sbmh_lookup_char(data, pos + needleLength - 1) + + if ( + ch === lastNeedleChar && + this._sbmh_memcmp(data, pos, needleLength - 1) + ) { + this._lookbehind_size = 0 + ++this.matches + this.emit('info', true) + + return (this._bufpos = pos + needleLength) + } + pos += this._occ[ch] + } + + // No match. + + if (pos < 0) { + // There's too few data for Boyer-Moore-Horspool to run, + // so let's use a different algorithm to skip as much as + // we can. + // Forward pos until + // the trailing part of lookbehind + data + // looks like the beginning of the needle + // or until + // pos == 0 + while (pos < 0 && !this._sbmh_memcmp(data, pos, len - pos)) { ++pos } + } + + if (pos >= 0) { + // Discard lookbehind buffer. + this.emit('info', false, this._lookbehind, 0, this._lookbehind_size) + this._lookbehind_size = 0 + } else { + // Cut off part of the lookbehind buffer that has + // been processed and append the entire haystack + // into it. + const bytesToCutOff = this._lookbehind_size + pos + if (bytesToCutOff > 0) { + // The cut off data is guaranteed not to contain the needle. + this.emit('info', false, this._lookbehind, 0, bytesToCutOff) + } + + this._lookbehind.copy(this._lookbehind, 0, bytesToCutOff, + this._lookbehind_size - bytesToCutOff) + this._lookbehind_size -= bytesToCutOff + + data.copy(this._lookbehind, this._lookbehind_size) + this._lookbehind_size += len + + this._bufpos = len + return len + } + } + + pos += (pos >= 0) * this._bufpos + + // Lookbehind buffer is now empty. We only need to check if the + // needle is in the haystack. + if (data.indexOf(needle, pos) !== -1) { + pos = data.indexOf(needle, pos) + ++this.matches + if (pos > 0) { this.emit('info', true, data, this._bufpos, pos) } else { this.emit('info', true) } + + return (this._bufpos = pos + needleLength) + } else { + pos = len - needleLength + } + + // There was no match. If there's trailing haystack data that we cannot + // match yet using the Boyer-Moore-Horspool algorithm (because the trailing + // data is less than the needle size) then match using a modified + // algorithm that starts matching from the beginning instead of the end. + // Whatever trailing data is left after running this algorithm is added to + // the lookbehind buffer. + while ( + pos < len && + ( + data[pos] !== needle[0] || + ( + (Buffer.compare( + data.subarray(pos, pos + len - pos), + needle.subarray(0, len - pos) + ) !== 0) + ) + ) + ) { + ++pos + } + if (pos < len) { + data.copy(this._lookbehind, 0, pos, pos + (len - pos)) + this._lookbehind_size = len - pos + } + + // Everything until pos is guaranteed not to contain needle data. + if (pos > 0) { this.emit('info', false, data, this._bufpos, pos < len ? pos : len) } + + this._bufpos = len + return len +} + +SBMH.prototype._sbmh_lookup_char = function (data, pos) { + return (pos < 0) + ? this._lookbehind[this._lookbehind_size + pos] + : data[pos] +} + +SBMH.prototype._sbmh_memcmp = function (data, pos, len) { + for (var i = 0; i < len; ++i) { // eslint-disable-line no-var + if (this._sbmh_lookup_char(data, pos + i) !== this._needle[i]) { return false } + } + return true +} + +module.exports = SBMH |