implement resolve

Author: poga

README.md

@@ -15,4 +15,7 @@ var archive = drive.createArchive()
 ln.link(archive, 'linkfile', <ARCHIVE KEY>, cb) // create symlink to another archive
 ln.readlink(archive, 'linkfile', cb) // get linked archive key
 ln.read(drive, archive, 'linkfile', cb) // returns a hyperdrive archive pointed to linked archive
+
+// assume link(archive, 'path/to/file', <ARCHIVE KEY>)
+ln.resolve(drive, archive, 'path/to/file/within/linked/archive', cb) // returns (err, nextArchive(<ARCHIVE KEY>, 'within/linked/archive'))
 ```

index.js

@@ -1,24 +1,26 @@
-const collect = require('stream-collect')
+const collect = require('collect-stream')
 const Readable = require('stream').Readable
 
-module.exports = {read, readlink, link}
+module.exports = {read, readlink, link, resolve}
 
 function readlink (archive, entry, cb) {
-  collect(archive.createFileReadStream(entry), body => {
+  collect(archive.createFileReadStream(entry), (err, body) => {
+    if (err) return cb(err, null)
+    var l
     try {
-      var l = decode(body)
-      if (!l) return cb(new Error('no link found'))
-      cb(null, l)
+      l = decode(body)
     } catch (e) {
-      cb(e)
+      return cb(new Error('not a link'), null)
     }
+    if (!l) return cb(new Error('not a link'), null)
+    cb(null, l)
   })
 }
 
 function read (drive, archive, entry, cb) {
-  readlink(archive, entry, (err, info) => {
+  readlink(archive, entry, (err, key) => {
     if (err) return cb(err)
-    cb(null, drive.createArchive(info))
+    cb(null, drive.createArchive(key))
   })
 }
 
@@ -30,7 +32,44 @@ function link (archive, entry, destArchiveKey, cb) {
   s.pipe(w).on('finish', cb)
 }
 
+function resolve (drive, archive, path, cb) {
+  var components = path.split('/')
+  var partialPath = []
+  var found = false
+  archive.list((err, entries) => {
+    if (err) return cb(err)
+    for (var i = 0; i < components.length; i++) {
+      var c = components[i]
+      partialPath.push(c)
+
+      if (exist(entries, partialPath)) {
+        read(drive, archive, partialPath.join('/'), (err, linkedArchive) => {
+          if (err && err.message === 'not a link') {
+            return cb(new Error(`unresolvable at ${partialPath.join('/')}`))
+          }
+          if (err) return cb(err)
+
+          return cb(null, linkedArchive, components.slice(i + 1).join('/'))
+        })
+        found = true
+        break
+      }
+    }
+
+    if (!found) {
+      cb(new Error(`unresolvable path ${path}`))
+    }
+  })
+
+  function exist (entries, partialPath) {
+    if (entries.find(x => x.name === partialPath.join('/'))) return true
+
+    return false
+  }
+}
+
 function encode (destKey) {
+  if (destKey instanceof Buffer) return JSON.stringify({l: destKey.toString('hex')})
   return JSON.stringify({l: destKey})
 }
 

package.json

@@ -6,7 +6,7 @@
   "main": "index.js",
   "license": "MIT",
   "dependencies": {
-    "stream-collect": "^1.3.1"
+    "collect-stream": "^1.2.1"
   },
   "keywords": [
     "hyperdrive",

test.js

@@ -1,6 +1,7 @@
 const tape = require('tape')
 const memdb = require('memdb')
 const hyperdrive = require('hyperdrive')
+const Readable = require('stream').Readable
 
 const ln = require('.')
 
@@ -21,3 +22,55 @@ tape('link', function (t) {
     })
   })
 })
+
+tape('resolve', function (t) {
+  var drive = hyperdrive(memdb())
+  var archive = drive.createArchive()
+
+  var drive2 = hyperdrive(memdb())
+
+  var linkedArchive = drive.createArchive({live: false})
+  linkedArchive.finalize(() => {
+    ln.link(archive, '/foo/link', linkedArchive.key, err => {
+      t.error(err)
+
+      ln.resolve(drive2, archive, '/foo/link/bar/baz.txt', (err, nextArchive, nextPath) => {
+        t.error(err)
+        t.same(nextArchive.key, linkedArchive.key)
+        t.same(nextPath, 'bar/baz.txt')
+        t.end()
+      })
+    })
+  })
+})
+
+tape('unresolvable not exists', function (t) {
+  var drive = hyperdrive(memdb())
+  var archive = drive.createArchive()
+
+  ln.resolve(drive, archive, '/foo/link/bar/baz.txt', (err, nextArchive, nextPath) => {
+    t.same(err.message, 'unresolvable path /foo/link/bar/baz.txt')
+    t.end()
+  })
+})
+
+tape('unresolvable not link', function (t) {
+  var drive = hyperdrive(memdb())
+  var archive = drive.createArchive()
+
+  write('baz').pipe(archive.createFileWriteStream('/foo/link')).on('finish', test)
+
+  function test () {
+    ln.resolve(drive, archive, '/foo/link/bar/baz.txt', (err, nextArchive, nextPath) => {
+      t.same(err.message, 'unresolvable at /foo/link')
+      t.end()
+    })
+  }
+})
+
+function write (str) {
+  var s = new Readable()
+  s.push(str)
+  s.push(null)
+  return s
+}

yarn.lock

@@ -177,6 +177,13 @@ cipher-base@^1.0.1:
   dependencies:
     inherits "^2.0.1"
 
+collect-stream@^1.2.1:
+  version "1.2.1"
+  resolved "https://registry.yarnpkg.com/collect-stream/-/collect-stream-1.2.1.tgz#829b41746431b1e27e01e6cd3d0ac163c22a1ca7"
+  dependencies:
+    concat-stream "^1.2.0"
+    once "^1.3.0"
+
 combined-stream@^1.0.5, combined-stream@~1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/combined-stream/-/combined-stream-1.0.5.tgz#938370a57b4a51dea2c77c15d5c5fdf895164009"
@@ -193,6 +200,14 @@ concat-map@0.0.1:
   version "0.0.1"
   resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
 
+concat-stream@^1.2.0:
+  version "1.5.2"
+  resolved "https://registry.yarnpkg.com/concat-stream/-/concat-stream-1.5.2.tgz#708978624d856af41a5a741defdd261da752c266"
+  dependencies:
+    inherits "~2.0.1"
+    readable-stream "~2.0.0"
+    typedarray "~0.0.5"
+
 concat-stream@~1.4.5:
   version "1.4.10"
   resolved "https://registry.yarnpkg.com/concat-stream/-/concat-stream-1.4.10.tgz#acc3bbf5602cb8cc980c6ac840fa7d8603e3ef36"
@@ -239,9 +254,9 @@ dashdash@^1.12.0:
   dependencies:
     assert-plus "^1.0.0"
 
-debug@^2.1.1, debug@^2.2.0, debug@^2.3.2:
-  version "2.3.3"
-  resolved "https://registry.yarnpkg.com/debug/-/debug-2.3.3.tgz#40c453e67e6e13c901ddec317af8986cda9eff8c"
+debug@^2.2.0, debug@^2.3.2:
+  version "2.4.1"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-2.4.1.tgz#ef2532d2753d282045c13c82ce47a09e56b91d53"
   dependencies:
     ms "0.7.2"
 
@@ -405,7 +420,7 @@ esutils@~1.0.0:
 
 execspawn@^1.0.1:
   version "1.0.1"
-  resolved "https://registry.yarnpkg.com/execspawn/-/execspawn-1.0.1.tgz#8286f9dde7cecde7905fbdc04e24f368f23f8da6"
+  resolved "http://registry.npmjs.org/execspawn/-/execspawn-1.0.1.tgz#8286f9dde7cecde7905fbdc04e24f368f23f8da6"
   dependencies:
     util-extend "^1.0.1"
 
@@ -1110,16 +1125,6 @@ process-nextick-args@~1.0.6:
   version "1.0.7"
   resolved "https://registry.yarnpkg.com/process-nextick-args/-/process-nextick-args-1.0.7.tgz#150e20b756590ad3f91093f25a4f2ad8bff30ba3"
 
-promise-polyfill@~2.0.2:
-  version "2.0.2"
-  resolved "https://registry.yarnpkg.com/promise-polyfill/-/promise-polyfill-2.0.2.tgz#3908dda91f5d130bfb3d09b3e1f77c37c4cb2669"
-
-promise-util@^1.1.0:
-  version "1.2.0"
-  resolved "https://registry.yarnpkg.com/promise-util/-/promise-util-1.2.0.tgz#838a3b6c349eb94e60eb42a972d73055bc6634af"
-  dependencies:
-    require-promise "1.0.1"
-
 protocol-buffers-schema@^3.1.1:
   version "3.1.1"
   resolved "https://registry.yarnpkg.com/protocol-buffers-schema/-/protocol-buffers-schema-3.1.1.tgz#b5e4800ce8adab7fb8ffe8770bb36e2a04359c78"
@@ -1224,22 +1229,22 @@ readable-stream@^1.0.33, readable-stream@~1.1.9:
     isarray "0.0.1"
     string_decoder "~0.10.x"
 
-readable-stream@^2.0.0, "readable-stream@^2.0.0 || ^1.1.13", readable-stream@^2.0.4, readable-stream@^2.0.5, readable-stream@^2.1.4, readable-stream@^2.1.5:
-  version "2.2.2"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.2.2.tgz#a9e6fec3c7dda85f8bb1b3ba7028604556fc825e"
+readable-stream@^2.0.0, readable-stream@~2.0.0, readable-stream@~2.0.5:
+  version "2.0.6"
+  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.0.6.tgz#8f90341e68a53ccc928788dacfcd11b36eb9b78e"
   dependencies:
-    buffer-shims "^1.0.0"
     core-util-is "~1.0.0"
     inherits "~2.0.1"
     isarray "~1.0.0"
     process-nextick-args "~1.0.6"
     string_decoder "~0.10.x"
     util-deprecate "~1.0.1"
 
-readable-stream@~2.0.5:
-  version "2.0.6"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.0.6.tgz#8f90341e68a53ccc928788dacfcd11b36eb9b78e"
+"readable-stream@^2.0.0 || ^1.1.13", readable-stream@^2.0.4, readable-stream@^2.0.5, readable-stream@^2.1.4, readable-stream@^2.1.5:
+  version "2.2.2"
+  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.2.2.tgz#a9e6fec3c7dda85f8bb1b3ba7028604556fc825e"
   dependencies:
+    buffer-shims "^1.0.0"
     core-util-is "~1.0.0"
     inherits "~2.0.1"
     isarray "~1.0.0"
@@ -1272,12 +1277,6 @@ request@2:
     tunnel-agent "~0.4.1"
     uuid "^3.0.0"
 
-require-promise@1.0.1:
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/require-promise/-/require-promise-1.0.1.tgz#286508d4b609fe9a439daef714ea721b4f655c22"
-  dependencies:
-    promise-polyfill "~2.0.2"
-
 resolve@^1.1.5, resolve@~1.1.7:
   version "1.1.7"
   resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.1.7.tgz#203114d82ad2c5ed9e8e0411b3932875e889e97b"
@@ -1409,13 +1408,6 @@ static-module@^1.1.0:
     static-eval "~0.2.0"
     through2 "~0.4.1"
 
-stream-collect@^1.3.1:
-  version "1.3.1"
-  resolved "https://registry.yarnpkg.com/stream-collect/-/stream-collect-1.3.1.tgz#f55ded11ec88a06d441089609c775a54e383712d"
-  dependencies:
-    debug "^2.1.1"
-    promise-util "^1.1.0"
-
 stream-collector@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/stream-collector/-/stream-collector-1.0.1.tgz#4d4e55f171356121b2c5f6559f944705ab28db15"