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/**
* Compare files line by line with options to ignore
* line endings and white space differencies.
*/
var fs = require('fs')
var FileDescriptorQueue = require('../fs/FileDescriptorQueue')
var closeFilesSync = require('./closeFile').closeFilesSync
var closeFilesAsync = require('./closeFile').closeFilesAsync
var fsPromise = require('../fs/fsPromise')
var BufferPool = require('../fs/BufferPool')
const LINE_TOKENIZER_REGEXP = /[^\n]+\n?|\n/g
const TRIM_LINE_ENDING_REGEXP = /\r\n$/g
const SPLIT_CONTENT_AND_LINE_ENDING_REGEXP = /([^\r\n]*)([\r\n]*)/
const TRIM_WHITE_SPACES_REGEXP = /^[ \f\t\v\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff]+|[ \f\t\v\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff]+$/g
var MAX_CONCURRENT_FILE_COMPARE = 8
var BUF_SIZE = 100000
var fdQueue = new FileDescriptorQueue(MAX_CONCURRENT_FILE_COMPARE * 2)
var bufferPool = new BufferPool(BUF_SIZE, MAX_CONCURRENT_FILE_COMPARE); // fdQueue guarantees there will be no more than MAX_CONCURRENT_FILE_COMPARE async processes accessing the buffers concurrently
function compareSync(path1, stat1, path2, stat2, options) {
var fd1, fd2
var bufferPair = bufferPool.allocateBuffers()
var bufferSize = options.lineBasedHandlerBufferSize || BUF_SIZE
try {
fd1 = fs.openSync(path1, 'r')
fd2 = fs.openSync(path2, 'r')
var buf1 = bufferPair.buf1
var buf2 = bufferPair.buf2
var nextPosition1 = 0, nextPosition2 = 0
while (true) {
var lines1 = readLinesSync(fd1, buf1, bufferSize, nextPosition1)
var lines2 = readLinesSync(fd2, buf2, bufferSize, nextPosition2)
if (lines1.length === 0 && lines2.length === 0) {
// End of file reached
return true
}
var equalLines = compareLines(lines1, lines2, options)
if (equalLines === 0) {
return false
}
nextPosition1 += calculateSize(lines1, equalLines)
nextPosition2 += calculateSize(lines2, equalLines)
}
} finally {
closeFilesSync(fd1, fd2)
bufferPool.freeBuffers(bufferPair)
}
}
async function compareAsync(path1, stat1, path2, stat2, options) {
var fd1, fd2
var bufferSize = options.lineBasedHandlerBufferSize || BUF_SIZE
var bufferPair
try {
var fds = await Promise.all([fdQueue.promises.open(path1, 'r'), fdQueue.promises.open(path2, 'r')])
bufferPair = bufferPool.allocateBuffers()
fd1 = fds[0]
fd2 = fds[1]
var buf1 = bufferPair.buf1
var buf2 = bufferPair.buf2
var nextPosition1 = 0, nextPosition2 = 0
while (true) {
var lines1 = await readLinesAsync(fd1, buf1, bufferSize, nextPosition1)
var lines2 = await readLinesAsync(fd2, buf2, bufferSize, nextPosition2)
if (lines1.length === 0 && lines2.length === 0) {
// End of file reached
return true
}
var equalLines = compareLines(lines1, lines2, options)
if (equalLines === 0) {
return false
}
nextPosition1 += calculateSize(lines1, equalLines)
nextPosition2 += calculateSize(lines2, equalLines)
}
} finally {
bufferPool.freeBuffers(bufferPair)
await closeFilesAsync(fd1, fd2, fdQueue)
}
}
/**
* Read lines from file starting with nextPosition.
* Returns 0 lines if eof is reached, otherwise returns at least one complete line.
*/
function readLinesSync(fd, buf, bufferSize, nextPosition) {
var lines = []
var chunk = ""
while (true) {
var size = fs.readSync(fd, buf, 0, bufferSize, nextPosition)
if (size === 0) {
// end of file
normalizeLastFileLine(lines)
return lines
}
chunk += buf.toString('utf8', 0, size)
lines = chunk.match(LINE_TOKENIZER_REGEXP)
if (lines.length > 1) {
return removeLastIncompleteLine(lines)
}
nextPosition += size
}
}
/**
* Read lines from file starting with nextPosition.
* Returns 0 lines if eof is reached, otherwise returns at least one complete line.
*/
async function readLinesAsync(fd, buf, bufferSize, nextPosition) {
var lines = []
var chunk = ""
while (true) {
var size = await fsPromise.read(fd, buf, 0, bufferSize, nextPosition)
if (size === 0) {
// end of file
normalizeLastFileLine(lines)
return lines
}
chunk += buf.toString('utf8', 0, size)
lines = chunk.match(LINE_TOKENIZER_REGEXP)
if (lines.length > 1) {
return removeLastIncompleteLine(lines)
}
nextPosition += size
}
}
function removeLastIncompleteLine(lines) {
const lastLine = lines[lines.length - 1]
if (!lastLine.endsWith('\n')) {
return lines.slice(0, lines.length - 1)
}
return lines
}
function normalizeLastFileLine(lines) {
if (lines.length === 0) {
return
}
const lastLine = lines[lines.length - 1]
if (!lastLine.endsWith('\n')) {
lines[lines.length - 1] = lastLine + '\n'
}
}
function calculateSize(lines, numberOfLines) {
var size = 0
for (var i = 0; i < numberOfLines; i++) {
var line = lines[i]
size += line.length
}
return size
}
function compareLines(lines1, lines2, options) {
var equalLines = 0
var len = lines1.length < lines2.length ? lines1.length : lines2.length
for (var i = 0; i < len; i++) {
var line1 = lines1[i]
var line2 = lines2[i]
if (options.ignoreLineEnding) {
line1 = trimLineEnding(line1)
line2 = trimLineEnding(line2)
}
if (options.ignoreWhiteSpaces) {
line1 = trimSpaces(line1)
line2 = trimSpaces(line2)
}
if (line1 !== line2) {
return equalLines
}
equalLines++
}
return equalLines
}
// Trims string like ' abc \n' into 'abc\n'
function trimSpaces(s) {
var matchResult = s.match(SPLIT_CONTENT_AND_LINE_ENDING_REGEXP);
var content = matchResult[1]
var lineEnding = matchResult[2]
var trimmed = content.replace(TRIM_WHITE_SPACES_REGEXP, '')
return trimmed + lineEnding
}
// Trims string like 'abc\r\n' into 'abc\n'
function trimLineEnding(s) {
return s.replace(TRIM_LINE_ENDING_REGEXP, '\n')
}
module.exports = {
compareSync: compareSync,
compareAsync: compareAsync
}
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