* first action! (#1)

node_modules/tar/lib/replace.js

@@ -0,0 +1,220 @@
+'use strict'
+const Buffer = require('./buffer.js')
+
+// tar -r
+const hlo = require('./high-level-opt.js')
+const Pack = require('./pack.js')
+const Parse = require('./parse.js')
+const fs = require('fs')
+const fsm = require('fs-minipass')
+const t = require('./list.js')
+const path = require('path')
+
+// starting at the head of the file, read a Header
+// If the checksum is invalid, that's our position to start writing
+// If it is, jump forward by the specified size (round up to 512)
+// and try again.
+// Write the new Pack stream starting there.
+
+const Header = require('./header.js')
+
+const r = module.exports = (opt_, files, cb) => {
+  const opt = hlo(opt_)
+
+  if (!opt.file)
+    throw new TypeError('file is required')
+
+  if (opt.gzip)
+    throw new TypeError('cannot append to compressed archives')
+
+  if (!files || !Array.isArray(files) || !files.length)
+    throw new TypeError('no files or directories specified')
+
+  files = Array.from(files)
+
+  return opt.sync ? replaceSync(opt, files)
+    : replace(opt, files, cb)
+}
+
+const replaceSync = (opt, files) => {
+  const p = new Pack.Sync(opt)
+
+  let threw = true
+  let fd
+  let position
+
+  try {
+    try {
+      fd = fs.openSync(opt.file, 'r+')
+    } catch (er) {
+      if (er.code === 'ENOENT')
+        fd = fs.openSync(opt.file, 'w+')
+      else
+        throw er
+    }
+
+    const st = fs.fstatSync(fd)
+    const headBuf = Buffer.alloc(512)
+
+    POSITION: for (position = 0; position < st.size; position += 512) {
+      for (let bufPos = 0, bytes = 0; bufPos < 512; bufPos += bytes) {
+        bytes = fs.readSync(
+          fd, headBuf, bufPos, headBuf.length - bufPos, position + bufPos
+        )
+
+        if (position === 0 && headBuf[0] === 0x1f && headBuf[1] === 0x8b)
+          throw new Error('cannot append to compressed archives')
+
+        if (!bytes)
+          break POSITION
+      }
+
+      let h = new Header(headBuf)
+      if (!h.cksumValid)
+        break
+      let entryBlockSize = 512 * Math.ceil(h.size / 512)
+      if (position + entryBlockSize + 512 > st.size)
+        break
+      // the 512 for the header we just parsed will be added as well
+      // also jump ahead all the blocks for the body
+      position += entryBlockSize
+      if (opt.mtimeCache)
+        opt.mtimeCache.set(h.path, h.mtime)
+    }
+    threw = false
+
+    streamSync(opt, p, position, fd, files)
+  } finally {
+    if (threw)
+      try { fs.closeSync(fd) } catch (er) {}
+  }
+}
+
+const streamSync = (opt, p, position, fd, files) => {
+  const stream = new fsm.WriteStreamSync(opt.file, {
+    fd: fd,
+    start: position
+  })
+  p.pipe(stream)
+  addFilesSync(p, files)
+}
+
+const replace = (opt, files, cb) => {
+  files = Array.from(files)
+  const p = new Pack(opt)
+
+  const getPos = (fd, size, cb_) => {
+    const cb = (er, pos) => {
+      if (er)
+        fs.close(fd, _ => cb_(er))
+      else
+        cb_(null, pos)
+    }
+
+    let position = 0
+    if (size === 0)
+      return cb(null, 0)
+
+    let bufPos = 0
+    const headBuf = Buffer.alloc(512)
+    const onread = (er, bytes) => {
+      if (er)
+        return cb(er)
+      bufPos += bytes
+      if (bufPos < 512 && bytes)
+        return fs.read(
+          fd, headBuf, bufPos, headBuf.length - bufPos,
+          position + bufPos, onread
+        )
+
+      if (position === 0 && headBuf[0] === 0x1f && headBuf[1] === 0x8b)
+        return cb(new Error('cannot append to compressed archives'))
+
+      // truncated header
+      if (bufPos < 512)
+        return cb(null, position)
+
+      const h = new Header(headBuf)
+      if (!h.cksumValid)
+        return cb(null, position)
+
+      const entryBlockSize = 512 * Math.ceil(h.size / 512)
+      if (position + entryBlockSize + 512 > size)
+        return cb(null, position)
+
+      position += entryBlockSize + 512
+      if (position >= size)
+        return cb(null, position)
+
+      if (opt.mtimeCache)
+        opt.mtimeCache.set(h.path, h.mtime)
+      bufPos = 0
+      fs.read(fd, headBuf, 0, 512, position, onread)
+    }
+    fs.read(fd, headBuf, 0, 512, position, onread)
+  }
+
+  const promise = new Promise((resolve, reject) => {
+    p.on('error', reject)
+    let flag = 'r+'
+    const onopen = (er, fd) => {
+      if (er && er.code === 'ENOENT' && flag === 'r+') {
+        flag = 'w+'
+        return fs.open(opt.file, flag, onopen)
+      }
+
+      if (er)
+        return reject(er)
+
+      fs.fstat(fd, (er, st) => {
+        if (er)
+          return reject(er)
+        getPos(fd, st.size, (er, position) => {
+          if (er)
+            return reject(er)
+          const stream = new fsm.WriteStream(opt.file, {
+            fd: fd,
+            start: position
+          })
+          p.pipe(stream)
+          stream.on('error', reject)
+          stream.on('close', resolve)
+          addFilesAsync(p, files)
+        })
+      })
+    }
+    fs.open(opt.file, flag, onopen)
+  })
+
+  return cb ? promise.then(cb, cb) : promise
+}
+
+const addFilesSync = (p, files) => {
+  files.forEach(file => {
+    if (file.charAt(0) === '@')
+      t({
+        file: path.resolve(p.cwd, file.substr(1)),
+        sync: true,
+        noResume: true,
+        onentry: entry => p.add(entry)
+      })
+    else
+      p.add(file)
+  })
+  p.end()
+}
+
+const addFilesAsync = (p, files) => {
+  while (files.length) {
+    const file = files.shift()
+    if (file.charAt(0) === '@')
+      return t({
+        file: path.resolve(p.cwd, file.substr(1)),
+        noResume: true,
+        onentry: entry => p.add(entry)
+      }).then(_ => addFilesAsync(p, files))
+    else
+      p.add(file)
+  }
+  p.end()
+}