* first action! (#1)

node_modules/cacache/lib/content/read.js

@@ -0,0 +1,195 @@
+'use strict'
+
+const BB = require('bluebird')
+
+const contentPath = require('./path')
+const figgyPudding = require('figgy-pudding')
+const fs = require('graceful-fs')
+const PassThrough = require('stream').PassThrough
+const pipe = BB.promisify(require('mississippi').pipe)
+const ssri = require('ssri')
+const Y = require('../util/y.js')
+
+const lstatAsync = BB.promisify(fs.lstat)
+const readFileAsync = BB.promisify(fs.readFile)
+
+const ReadOpts = figgyPudding({
+  size: {}
+})
+
+module.exports = read
+function read (cache, integrity, opts) {
+  opts = ReadOpts(opts)
+  return withContentSri(cache, integrity, (cpath, sri) => {
+    return readFileAsync(cpath, null).then(data => {
+      if (typeof opts.size === 'number' && opts.size !== data.length) {
+        throw sizeError(opts.size, data.length)
+      } else if (ssri.checkData(data, sri)) {
+        return data
+      } else {
+        throw integrityError(sri, cpath)
+      }
+    })
+  })
+}
+
+module.exports.sync = readSync
+function readSync (cache, integrity, opts) {
+  opts = ReadOpts(opts)
+  return withContentSriSync(cache, integrity, (cpath, sri) => {
+    const data = fs.readFileSync(cpath)
+    if (typeof opts.size === 'number' && opts.size !== data.length) {
+      throw sizeError(opts.size, data.length)
+    } else if (ssri.checkData(data, sri)) {
+      return data
+    } else {
+      throw integrityError(sri, cpath)
+    }
+  })
+}
+
+module.exports.stream = readStream
+module.exports.readStream = readStream
+function readStream (cache, integrity, opts) {
+  opts = ReadOpts(opts)
+  const stream = new PassThrough()
+  withContentSri(cache, integrity, (cpath, sri) => {
+    return lstatAsync(cpath).then(stat => ({ cpath, sri, stat }))
+  }).then(({ cpath, sri, stat }) => {
+    return pipe(
+      fs.createReadStream(cpath),
+      ssri.integrityStream({
+        integrity: sri,
+        size: opts.size
+      }),
+      stream
+    )
+  }).catch(err => {
+    stream.emit('error', err)
+  })
+  return stream
+}
+
+let copyFileAsync
+if (fs.copyFile) {
+  module.exports.copy = copy
+  module.exports.copy.sync = copySync
+  copyFileAsync = BB.promisify(fs.copyFile)
+}
+
+function copy (cache, integrity, dest, opts) {
+  opts = ReadOpts(opts)
+  return withContentSri(cache, integrity, (cpath, sri) => {
+    return copyFileAsync(cpath, dest)
+  })
+}
+
+function copySync (cache, integrity, dest, opts) {
+  opts = ReadOpts(opts)
+  return withContentSriSync(cache, integrity, (cpath, sri) => {
+    return fs.copyFileSync(cpath, dest)
+  })
+}
+
+module.exports.hasContent = hasContent
+function hasContent (cache, integrity) {
+  if (!integrity) { return BB.resolve(false) }
+  return withContentSri(cache, integrity, (cpath, sri) => {
+    return lstatAsync(cpath).then(stat => ({ size: stat.size, sri, stat }))
+  }).catch(err => {
+    if (err.code === 'ENOENT') { return false }
+    if (err.code === 'EPERM') {
+      if (process.platform !== 'win32') {
+        throw err
+      } else {
+        return false
+      }
+    }
+  })
+}
+
+module.exports.hasContent.sync = hasContentSync
+function hasContentSync (cache, integrity) {
+  if (!integrity) { return false }
+  return withContentSriSync(cache, integrity, (cpath, sri) => {
+    try {
+      const stat = fs.lstatSync(cpath)
+      return { size: stat.size, sri, stat }
+    } catch (err) {
+      if (err.code === 'ENOENT') { return false }
+      if (err.code === 'EPERM') {
+        if (process.platform !== 'win32') {
+          throw err
+        } else {
+          return false
+        }
+      }
+    }
+  })
+}
+
+function withContentSri (cache, integrity, fn) {
+  return BB.try(() => {
+    const sri = ssri.parse(integrity)
+    // If `integrity` has multiple entries, pick the first digest
+    // with available local data.
+    const algo = sri.pickAlgorithm()
+    const digests = sri[algo]
+    if (digests.length <= 1) {
+      const cpath = contentPath(cache, digests[0])
+      return fn(cpath, digests[0])
+    } else {
+      return BB.any(sri[sri.pickAlgorithm()].map(meta => {
+        return withContentSri(cache, meta, fn)
+      }, { concurrency: 1 }))
+        .catch(err => {
+          if ([].some.call(err, e => e.code === 'ENOENT')) {
+            throw Object.assign(
+              new Error('No matching content found for ' + sri.toString()),
+              { code: 'ENOENT' }
+            )
+          } else {
+            throw err[0]
+          }
+        })
+    }
+  })
+}
+
+function withContentSriSync (cache, integrity, fn) {
+  const sri = ssri.parse(integrity)
+  // If `integrity` has multiple entries, pick the first digest
+  // with available local data.
+  const algo = sri.pickAlgorithm()
+  const digests = sri[algo]
+  if (digests.length <= 1) {
+    const cpath = contentPath(cache, digests[0])
+    return fn(cpath, digests[0])
+  } else {
+    let lastErr = null
+    for (const meta of sri[sri.pickAlgorithm()]) {
+      try {
+        return withContentSriSync(cache, meta, fn)
+      } catch (err) {
+        lastErr = err
+      }
+    }
+    if (lastErr) { throw lastErr }
+  }
+}
+
+function sizeError (expected, found) {
+  var err = new Error(Y`Bad data size: expected inserted data to be ${expected} bytes, but got ${found} instead`)
+  err.expected = expected
+  err.found = found
+  err.code = 'EBADSIZE'
+  return err
+}
+
+function integrityError (sri, path) {
+  var err = new Error(Y`Integrity verification failed for ${sri} (${path})`)
+  err.code = 'EINTEGRITY'
+  err.sri = sri
+  err.path = path
+  return err
+}